Sensing Parts per Million Level Ammonia and Parts per Billion Level Acetic Acid in the Gas Phase by Common Black Film with a Fluorescent pH Probe.

PubMed

Fu, Jingni; Zhang, Luning

2018-01-16

Relying on the nanometer-thick water core and large surface area-to-volume ratio (∼2 × 10 8 m -1 ) of common black film (CBF), we are able to use a pH-sensitive dye (carboxy-seminaphthorhodafluor-1, SNARF-1) to detect ammonia and acetic acid gas adsorption into the CBF, with the limit of detection reaching 0.8 ppm for NH 3 gas and 3 ppb for CH 3 COOH gas in the air. Data analysis reveals that fluorescence signal change is linearly proportional to the gas concentration up to 15 ppm and 65 ppb for NH 3 and CH 3 COOH, respectively.

40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

Code of Federal Regulations, 2014 CFR

2014-07-01

... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

Code of Federal Regulations, 2012 CFR

2012-07-01

... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

40 CFR 50.11 - National primary and secondary ambient air quality standards for oxides of nitrogen (with...

Code of Federal Regulations, 2013 CFR

2013-07-01

... air quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). 50.11 Section... quality standards for oxides of nitrogen (with nitrogen dioxide as the indicator). (a) The level of the national primary annual ambient air quality standard for oxides of nitrogen is 53 parts per billion (ppb...

76 FR 36471 - Approval and Promulgation of Air Quality Implementation Plans; Virginia; Adoption of the Revised...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-06-22

... Promulgation of Air Quality Implementation Plans; Virginia; Adoption of the Revised Nitrogen Dioxide Standard... of adding the new 1-hour nitrogen dioxide (NO 2 ) standard at a level of 100 parts per billion (ppb... Promulgation of Air Quality Implementation Plans; Virginia; Adoption of the Revised Nitrogen Dioxide Standards...

Spectroscopic detection of biological NO with a quantum cascade laser

NASA Technical Reports Server (NTRS)

Menzel, L.; Kosterev, A. A.; Curl, R. F.; Tittel, F. K.; Gmachl, C.; Capasso, F.; Sivco, D. L.; Baillargeon, J. N.; Hutchinson, A. L.; Cho, A. Y.;

Microfluidic Diatomite Analytical Devices for Illicit Drug Sensing with ppb-Level Sensitivity.

PubMed

Kong, Xianming; Chong, Xinyuan; Squire, Kenny; Wang, Alan X

2018-04-15

The escalating research interests in porous media microfluidics, such as microfluidic paper-based analytical devices, have fostered a new spectrum of biomedical devices for point-of-care (POC) diagnosis and biosensing. In this paper, we report microfluidic diatomite analytical devices (μDADs), which consist of highly porous photonic crystal biosilica channels, as an innovative lab-on-a-chip platform to detect illicit drugs. The μDADs in this work are fabricated by spin-coating and tape-stripping diatomaceous earth on regular glass slides with cross section of 400×30µm 2 . As the most unique feature, our μDADs can simultaneously perform on-chip chromatography to separate small molecules from complex biofluidic samples and acquire the surface-enhanced Raman scattering spectra of the target chemicals with high specificity. Owing to the ultra-small dimension of the diatomite microfluidic channels and the photonic crystal effect from the fossilized diatom frustules, we demonstrate unprecedented sensitivity down to part-per-billion (ppb) level when detecting pyrene (1ppb) from mixed sample with Raman dye and cocaine (10 ppb) from human plasma. This pioneering work proves the exclusive advantage of μDADs as emerging microfluidic devices for chemical and biomedical sensing, especially for POC drug screening.

Treated bottom ash medium and method of arsenic removal from drinking water

DOEpatents

Gadgil, Ashok

2009-06-09

A method for low-cost arsenic removal from drinking water using chemically prepared bottom ash pre-treated with ferrous sulfate and then sodium hydroxide. Deposits on the surface of particles of bottom ash form of activated iron adsorbent with a high affinity for arsenic. In laboratory tests, a miniscule 5 grams of pre-treated bottom ash was sufficient to remove the arsenic from 2 liters of 2400 ppb (parts per billion) arsenic-laden water to a level below 50 ppb (the present United States Environmental Protection Agency limit). By increasing the amount of pre-treated bottom ash, even lower levels of post-treatment arsenic are expected. It is further expected that this invention supplies a very low-cost solution to arsenic poisoning for large population segments.

Exhaled Nitric Oxide is Not a Biomarker for Pulmonary Tuberculosis.

PubMed

López, José W; Loader, Maria-Cristina I; Smith, Daniel; Pastorius, Daniel; Bravard, Marjory; Caviedes, Luz; Romero, Karina M; Clark, Taryn; Checkley, William; Ticona, Eduardo; Friedland, Jon S; Gilman, Robert H

2018-06-01

To reduce transmission of tuberculosis (TB) in resource-limited countries where TB remains a major cause of mortality, novel diagnostic tools are urgently needed. We evaluated the fractional concentration of exhaled nitric oxide (FeNO) as an easily measured, noninvasive potential biomarker for diagnosis and monitoring of treatment response in participants with pulmonary TB including multidrug resistant-TB in Lima, Peru. In a longitudinal study however, we found no differences in baseline median FeNO levels between 38 TB participants and 93 age-matched controls (13 parts per billion [ppb] [interquartile range (IQR) = 8-26] versus 15 ppb [IQR = 12-24]), and there was no change over 60 days of treatment (15 ppb [IQR = 10-19] at day 60). Taking this and previous evidence together, we conclude FeNO is not of value in either the diagnosis of pulmonary TB or as a marker of treatment response.

21 CFR 584.725 - 25-Hydroxyvitamin D3.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of use. This substance is generally recognized as safe as a source of vitamin D3 activity in feed or drinking water of broiler chickens when used in accordance with the limitations in paragraph (c) of this section. (c) Limitations. (1) Not to exceed 69 parts per billion (ppb) in feed or 34.5 ppb in drinking...

21 CFR 584.725 - 25-Hydroxyvitamin D3.

Code of Federal Regulations, 2012 CFR

2012-04-01

... of use. This substance is generally recognized as safe as a source of vitamin D3 activity in feed or drinking water of broiler chickens when used in accordance with the limitations in paragraph (c) of this section. (c) Limitations. (1) Not to exceed 69 parts per billion (ppb) in feed or 34.5 ppb in drinking...

21 CFR 584.725 - 25-Hydroxyvitamin D3.

Code of Federal Regulations, 2014 CFR

2014-04-01

... of use. This substance is generally recognized as safe as a source of vitamin D3 activity in feed or drinking water of broiler chickens when used in accordance with the limitations in paragraph (c) of this section. (c) Limitations. (1) Not to exceed 69 parts per billion (ppb) in feed or 34.5 ppb in drinking...

21 CFR 584.725 - 25-Hydroxyvitamin D3.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of use. This substance is generally recognized as safe as a source of vitamin D3 activity in feed or drinking water of broiler chickens when used in accordance with the limitations in paragraph (c) of this section. (c) Limitations. (1) Not to exceed 69 parts per billion (ppb) in feed or 34.5 ppb in drinking...

21 CFR 584.725 - 25-Hydroxyvitamin D3.

Code of Federal Regulations, 2013 CFR

2013-04-01

... of use. This substance is generally recognized as safe as a source of vitamin D3 activity in feed or drinking water of broiler chickens when used in accordance with the limitations in paragraph (c) of this section. (c) Limitations. (1) Not to exceed 69 parts per billion (ppb) in feed or 34.5 ppb in drinking...

Characterization of the Sukinda and Nausahi ultramafic complexes, Orissa, India by platinum-group element geochemistry

USGS Publications Warehouse

Page, N.J.; Banerji, P.K.; Haffty, J.

1985-01-01

Samples of 20 chromitite, 14 ultramafic and mafic rock, and 9 laterite and soil samples from the Precambrian Sukinda and Nausahi ultramafic complexes, Orissa, India were analyzed for platinum-group elements (PGE). The maximum concentrations are: palladium, 13 parts per billion (ppb); platinum, 120 ppb; rhodium, 21 ppb; iridium, 210 ppb; and ruthenium, 630 ppb. Comparison of chondrite-normalized ratios of PGE for the chromitite samples of lower Proterozoic to Archean age with similar data from Paleozoic and Mesozoic ophiolite complexes strongly implies that these complexes represent Precambrian analogs of ophiolite complexes. This finding is consistent with the geology and petrology of the Indian complexes and suggests that plate-tectonic and ocean basin developement models probably apply to some parts of Precambrian shield areas. ?? 1985.

Sub-parts-per-billion level detection of dimethyl methyl phosphonate (DMMP) by quantum cascade laser photoacoustic spectroscopy.

PubMed

Mukherjee, Anadi; Dunayevskiy, Ilya; Prasanna, Manu; Go, Rowel; Tsekoun, Alexei; Wang, Xiaojun; Fan, Jenyu; Patel, C Kumar N

2008-04-01

The need for the detection of chemical warfare agents (CWAs) is no longer confined to battlefield environments because of at least one confirmed terrorist attack, the Tokyo Subway [Emerg. Infect. Dis. 5, 513 (1999)] in 1995, and a suspected, i.e., a false-alarm of a CWA in the Russell Senate Office Building [Washington Post, 9 February 2006, p. B01]. Therefore, detection of CWAs with high sensitivity and low false-alarm rates is considered an important priority for ensuring public safety. We report a minimum detection level for a CWA simulant, dimethyl methyl phosphonate (DMMP), of <0.5 ppb (parts in 10(9)) by use of a widely tunable external grating cavity quantum cascade laser and photoacoustic spectroscopy. With interferents present in Santa Monica, California street air, we demonstrate a false-alarm rate of 1:10(6) at a detection threshold of 1.6 ppb.

Fractional exhaled nitric oxide has a good correlation with asthma control and lung function in latino children with asthma.

PubMed

Soto-Ramos, Mario; Castro-Rodríguez, Jose A; Hinojos-Gallardo, Luis Carlos; Hernández-Saldaña, Raul; Cisneros-Castolo, Martin; Carrillo-Rodríguez, Victor

2013-08-01

Although the measurement of fractional exhaled nitric oxide (FE(NO)) has been recommended for observational studies and clinical trials of asthma, FE(NO) has not been examined in studies of childhood asthma in Latin America, To examine the relationship between FE(NO) and indicators of disease control or severity [asthma control test/childhood asthma control test (ACT/C-ACT), lung function, and exercise challenge test (ECT)] in Mexican children with persistent asthma, Children (6-18 years of age) with persistent asthma were consecutively recruited in a tertiary asthma clinic and divided into two groups, e.g. FE(NO) < 20 parts per billion (ppb) and ≥20 ppb.Adequate FE(NO) measurements were obtained in 134 (83.2%) of 161 eligible children, Children with FE(NO)<20 ppb had significantly higher scores on the ACT/C-ACT than those with FE(NO) ≥ 20 ppb (median [interquartile range] :23 [20.8-25] vs. 21 [18-24], p = .002, respectively). Compared to children with FE(NO) ≥20 ppb, those with FE(NO) <20 ppb had a higher baseline predicted forced expiratory volume (FEV(1)) [94% (92.5%-99.4%) vs. 83% (81%-89.9%), p = .001] and a lower probability of having a positive ECT (42.7% vs. 71.2%, p = .001). In addition, FE(NO) was significantly inversely correlated with the participants' ACT/C-ACT score and predicted FEV1, and directly correlated with positive ECT, CONCLUSION: Among Mexican children with persistent asthma, low levels of FE(NO) ( <20 ppb) are associated with better asthma control, and higher lung function.

Current nitrogen dioxide exposures among railroad workers.

PubMed

Woskie, S R; Hammond, S K; Smith, T J; Schenker, M B

1989-07-01

As part of a series of epidemiologic studies of the mortality patterns of railroad workers, various air contaminants were measured to characterize the workers' current exposures to diesel exhaust. Nitrogen dioxide (NO2), which is a constituent of diesel exhaust, was examined as one possible marker of diesel exposure. An adaptation of the Palmes personal passive sampler was used to measure the NO2 exposures of 477 U.S. railroad workers at four railroads. The range of NO2 exposures expressed as the arithmetic average +/- two standard errors for the five career job groups were as follows: signal maintainers, 16-24 parts per billion (ppb); clerks/dispatchers/station agents, 23-43 ppb; engineers/firers, 26-38 ppb; brakers/conductors, 50-74 ppb; and locomotive shop workers, 95-127 ppb. Variations among railroads and across seasons were not significant for most job groups.

GIS-based assessment of cancer risk due to benzene in Tehran ambient air.

PubMed

Atabi, Farideh; Mirzahosseini, Seyed Alireza Hajiseyed

2013-10-01

The present study aimed to assess the risk of cancer due to benzene in the ambient air of gas stations and traffic zones in the north of Tehran. The cancer risk was estimated using the population distribution data for benzene levels and the unit risk for benzene proposed by the United States Environmental Protection Agency (US EPA). Sixteen sampling locations were monitored, once every week, during 5 April 2010 to 25 March 2011. The results showed that the mean annual benzene concentration was 14.51±3.17 parts per billion (ppb) for traffic zones and 29.01±1.32 ppb for outside gas stations. The risk calculated was 1026×10(-6) for gas station 27 and 955×10(-6) for gas station 139. According to our results, the annual benzene level in Tehran ambient air is 2 to 20 times higher than the respective value specified in International Standard (1.56 ppb). Moreover, the results showed a notable increase of cancer risks, ranging from 10% to 56%, for the vicinity population close to the gas stations in comparison to the vicinity population in the traffic zones.

6.6-hour inhalation of ozone concentrations from 60 to 87 parts per billion in healthy humans.

PubMed

Schelegle, Edward S; Morales, Christopher A; Walby, William F; Marion, Susan; Allen, Roblee P

2009-08-01

Identification of the minimal ozone (O(3)) concentration and/or dose that induces measurable lung function decrements in humans is considered in the risk assessment leading to establishing an appropriate National Ambient Air Quality Standard for O(3) that protects public health. To identify and/or predict the minimal mean O(3) concentration that produces a decrement in FEV(1) and symptoms in healthy individuals completing 6.6-hour exposure protocols. Pulmonary function and subjective symptoms were measured in 31 healthy adults (18-25 yr, male and female, nonsmokers) who completed five 6.6-hour chamber exposures: filtered air and four variable hourly patterns with mean O(3) concentrations of 60, 70, 80, and 87 parts per billion (ppb). Compared with filtered air, statistically significant decrements in FEV(1) and increases in total subjective symptoms scores (P < 0.05) were measured after exposure to mean concentrations of 70, 80, and 87 ppb O(3). The mean percent change in FEV(1) (+/-standard error) at the end of each protocol was 0.80 +/- 0.90, -2.72 +/- 1.48, -5.34 +/- 1.42, -7.02 +/- 1.60, and -11.42 +/- 2.20% for exposure to filtered air and 60, 70, 80, and 87 ppb O(3), respectively. Inhalation of 70 ppb O(3) for 6.6 hours, a concentration below the current 8-hour National Ambient Air Quality Standard of 75 ppb, is sufficient to induce statistically significant decrements in FEV(1) in healthy young adults.

Gas chromatography with pulsed flame photometric detection multiresidue method for organophosphate pesticide and metabolite residues at the parts-per-billion level in representatives commodities of fruits and vegetable crop groups.

PubMed

Podhorniak, L V; Negron, J F; Griffith, F D

2001-01-01

A gas chromatographic method with a pulsed flame photometric detector (P-FPD) is presented for the analysis of 28 parent organophosphate (OP) pesticides and their OP metabolites. A total of 57 organophosphates were analyzed in 10 representative fruit and vegetable crop groups. The method is based on a judicious selection of known procedures from FDA sources such as the Pesticide Analytical Manual and Laboratory Information Bulletins, combined in a manner to recover the OPs and their metabolite(s) at the part-per-billion (ppb) level. The method uses an acetone extraction with either miniaturized Hydromatrix column partitioning or alternately a miniaturized methylene dichloride liquid-liquid partitioning, followed by solid-phase extraction (SPE) cleanup with graphitized carbon black (GCB) and PSA cartridges. Determination of residues is by programmed temperature capillary column gas chromatography fitted with a P-FPD set in the phosphorus mode. The method is designed so that a set of samples can be prepared in 1 working day for overnight instrumental analysis. The recovery data indicates that a daily column-cutting procedure used in combination with the SPE extract cleanup effectively reduces matrix enhancement at the ppb level for many organophosphates. The OPs most susceptible to elevated recoveries around or greater than 150%, based on peak area calculations, were trichlorfon, phosmet, and the metabolites of dimethoate, fenamiphos, fenthion, and phorate.

Application of laser spectroscopy for measurement of exhaled ethane in patients with lung cancer.

PubMed

Skeldon, K D; McMillan, L C; Wyse, C A; Monk, S D; Gibson, G; Patterson, C; France, T; Longbottom, C; Padgett, M J

2006-02-01

There is increasing interest in ethane (C(2)H(6)) in exhaled breath as a non-invasive marker of oxidative stress (OS) and thereby a potential indicator of disease. However, the lack of real-time measurement techniques has limited progress in the field. Here we report on a novel Tunable Diode Laser Spectrometer (TDLS) applied to the analysis of exhaled ethane in patients with lung cancer. The patient group (n=52) comprised randomly selected patients presenting at a respiratory clinic. Of these, a sub-group (n=12) was subsequently diagnosed with lung cancer. An age-matched group (n=12) corresponding to the lung cancer group was taken from a larger control group of healthy adults (n=58). The concentration of ethane in a single exhaled breath sample collected from all subjects was later measured using the TDLS. This technique is capable of real-time analysis of samples with accuracy 0.1 parts per billion (ppb), over 10 times less than typical ambient levels in the northern hemisphere. After correcting for ambient background, ethane in the control group (26% smokers) ranged from 0 to 10.54 ppb (median of 1.9 ppb) while ethane in the lung cancer patients (42% smokers) ranged from 0 to 7.6 ppb (median of 0.7 ppb). Ethane among the non-lung cancer patients presenting for investigation of respiratory disease ranged from 0 to 25 ppb (median 1.45 ppb). We conclude that, while the TDLS proved effective for accurate and rapid sample analysis, there was no significant difference in exhaled ethane among any of the subject groups. Comments are made on the suitability of the technique for monitoring applications.

Do trees smart from ozone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Douglas-firs near Eatonville, Washington - 70 miles south of Seattle - are getting doses of ozone pollution at levels regularly found in Los Angeles. Ozone levels of 220 parts per billion (ppb) can make your eyes smart and give your Aunt Edna a doozy of a headache. University of Washington researchers are now trying to find if Douglas-fir is adversely affected by 220 ppb of ozone. They are also studying whether individual branches can reveal how whole trees respond to pollutants. Studying entire trees is tough so researchers hope to take the pulse of a tree by examining its branches.more » At the university's experimental forest, researchers have placed 12-foot-tall plastic-covered corrals around six Douglas-firs, each nine or 10 years old and up to 15 feet tall. Three of the trees receive filtered air while three others are blasted with 220 ppb of ozone for eight hours each day. Four individual branches on each tree are encased in their own plastic chambers. Two are dosed with filtered air and two with ozone. To date, the UW research is the only study in the US combining branch chambers with whole tree measurements. Now in its second year, the experiment is expected to yield information about growth and foliage health by measuring respiration, chlorophyll, photosynthesis, and nutrient uptake. Loss of tree vigor could lead to increased problems with pathogens and insects. In the summer of '88, surprisingly high levels of ozone - up to 196 ppb - were detected in forests downwind from Seattle, worse than the urban areas themselves.« less

A multifunctional azobenzene-based polymeric adsorbent for effective water remediation

PubMed Central

Wan, Decheng; Chen, Feng; Geng, Qingrui; Lu, Hang; Willcock, Helen; Liu, Qiuming; Wang, Fangyingkai; Zou, Kaidian; Jin, Ming; Pu, Hongting; Du, Jianzhong

2014-01-01

The efficient removal of trace carcinogenic organic pollutants, such as polycyclic aromatic hydrocarbons (PAHs) and ionic dyes, from water is an important technical challenge. We report a highly effective recyclable multifunctional azobenzene (AZ)-based silica-supported polymeric adsorbent which can simultaneously remove both PAHs and anionic dyes from water to below parts per billion (ppb) level based on multiple interactions such as the hydrophobic effect, π–π stacking and electrostatic interactions, thus providing a new strategy for designer water remediation materials. PMID:25465671

Evaporative Gasoline Emissions and Asthma Symptoms

PubMed Central

Gordian, Mary Ellen; Stewart, Alistair W; Morris, Stephen S

2010-01-01

Attached garages are known to be associated with indoor air volatile organic compounds (VOCs). This study looked at indoor exposure to VOCs presumably from evaporative emissions of gasoline. Alaskan gasoline contains 5% benzene making benzene a marker for gasoline exposure. A survey of randomly chosen houses with attached garages was done in Anchorage Alaska to determine the exposure and assess respiratory health. Householders were asked to complete a health survey for each person and a household survey. They monitored indoor air in their primary living space for benzene, toluene, ethylbenzene and xylenes for one week using passive organic vapor monitoring badges. Benzene levels in homes ranged from undetectable to 58 parts per billion. The median benzene level in 509 homes tested was 2.96 ppb. Elevated benzene levels in the home were strongly associated with small engines and gasoline stored in the garage. High concentrations of benzene in gasoline increase indoor air levels of benzene in residences with attached garages exposing people to benzene at levels above ATSDR’s minimal risk level. Residents reported more severe symptoms of asthma in the homes with high gasoline exposure (16%) where benzene levels exceeded the 9 ppb. PMID:20948946

Two-dimensional proteomic analysis of gonads of air-breathing catfish, Clarias batrachus after the exposure of endosulfan and malathion.

PubMed

Laldinsangi, C; Vijayaprasadarao, K; Rajakumar, A; Murugananthkumar, R; Prathibha, Y; Sudhakumari, C C; Mamta, S K; Dutta-Gupta, A; Senthilkumaran, B

2014-05-01

Endocrine disrupting chemicals have raised public concern, since their effects have been found to interfere with the physiological systems of various organisms, especially during critical stage of development and reproduction. Endosulfan and malathion, pesticides widely used for agricultural purposes, have been known to disrupt physiological functions in aquatic organisms. The current work analyzes the effects of endosulfan (2.5 parts per billion [ppb]) and malathion (10 ppb) on the reproductive physiology of catfish (Clarias batrachus) by evaluating protein expression profiles after 21 days of exposure. The proteomic profile of testis and ovary after exposure to endosulfan showed downregulation of proteins such as ubiquitin and Esco2, and upregulation in melanocortin-receptor-2 respectively. Malathion exposed ovary showed upregulated prolactin levels. Identification of proteins differentially expressed in gonads due to the exposure to these pesticides may serve as crucial indications to denote their disruptive effects at the level of proteins. Copyright © 2014 Elsevier B.V. All rights reserved.

7 CFR 996.11 - Negative aflatoxin content.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that have...

7 CFR 996.11 - Negative aflatoxin content.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS FOR DOMESTIC AND IMPORTED PEANUTS MARKETED IN THE UNITED STATES Definitions § 996.11 Negative aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that have...

Sub-ppb Oxygen Contaminant Detection in Semi-Conductor Processing

NASA Technical Reports Server (NTRS)

Man, K. F.

1995-01-01

Gaseous contaminants such as oxygen, water vapor, nitrogen and hydrocarbons are often present in the processing environment in semiconductor device fabrication and in containerless materials processing. The contaminants arise as a result of outgassing from hot surfaces or they may be part of the impurities in commercial ultra-high purity gases. Among these gaseous contaminants, oxygen is the most reactive and, therefore, has the most adverse effects on the end product. There has been an intense effort at the Jet Propulsion Laboratory to develop different types of oxygen sorbents to reduce oxygen concentration in a microgravity processing environment to sub-ppb (parts-per-billion) levels. Higher concentrations can lead to rapid surface oxide formation, hence reducing the quality of semiconductor devices. If the concentration of oxygen in a processing chamber at 1000oC is in the ppb level, it will only take approximately 10 seconds for an oxide layer to form on the surface of a sample. The interaction of oxygen with the water surface can lead to the formation of localized defects in semi-conductor devices, hence decreasing the manufacturing yield. For example, efficient production of 64 Mb RAM chips requires contaminations below ppb levels. This paper describes a technique for measuring trace quantities of oxygen contaminants by recording the monoatomic negative ions, O-, using mass spectrometry. The O- formation from the e--O2 interaction utilizes the electron dissociative attachment method that is greatly enhanced at the resonant energy (6.8 eV). The device combines a small gridded electron ionizer with a compact mass spectrometer. The concentrations of oxygen have been measured using the method of standard additions by diluting O2 in N2. The lowest detection limit obtained was 1.2 kHz (O- count rate) at a concentration of 10-10, corresponding to 0.1 ppb.

Measurement of sub-parts-per-billion levels of carbonyl compounds in marine air by a simple cartridge trapping procedure followed by liquid chromatography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xianliang, Zhou; Mopper, K.

1990-10-01

Carbonyl compounds in clean marine air were trapped onto 2,4-dinitrophenylhydrazine- (DNPH-) coated cartridges, and their hydrazone derivatives were separated by HPLC and detected by UV absorbance. More than 20 carbonyl compounds were isolated from marine air with >92% collection efficiency. The technique employs a highly effective reagent purification procedure, which results in much lower blanks compared to previously reported trapping techniques for carbonyl compounds. Blanks were routinely <0.07 ppb for formaldehyde and acetone and <0.02 ppb for the others. Humidity and reactive gases have no detectable effect on collection efficiencies. Carbonyl-DNPH derivatives eluted from the cartridges are stable in acetonitrilemore » for at least 2 weeks, which facilitates field studies. Several previously undetected unknown carbonyl compounds were found in marine air by this technique. Typical results for open ocean and coastal marine air are shown.« less

Active Hydrazine Vapor Sampler (AHVS)

NASA Technical Reports Server (NTRS)

Young, Rebecca C.; Mcbrearty, Charles F.; Curran, Daniel J.

1993-01-01

The Active Hydrazine Vapor Sampler (AHVS) was developed to detect vapors of hydrazine (HZ) and monomethylhydrazine (MMH) in air at parts-per-billion (ppb) concentration levels. The sampler consists of a commercial personal pump that draws ambient air through paper tape treated with vanillin (4-hydroxy-3-methoxybenzaldehyde). The paper tape is sandwiched in a thin cardboard housing inserted in one of the two specially designed holders to facilitate sampling. Contaminated air reacts with vanillin to develop a yellow color. The density of the color is proportional to the concentration of HZ or MMH. The AHVS can detect 10 ppb in less than 5 minutes. The sampler is easy to use, low cost, and intrinsically safe and contains no toxic material. It is most beneficial for use in locations with no laboratory capabilities for instrumentation calibration. This paper reviews the development, laboratory test, and field test of the device.

The need for congressional action to finance arsenic reductions in drinking water.

PubMed

Levine, Rebecca Leah

2012-11-01

Many public water systems in the U.S. are unsafe because the communities cannot afford to comply with the current 10 parts per billion (ppb) federal arsenic standard for drinking water. Communities unable to afford improvements remain vulnerable to adverse health effects associated with higher levels of arsenic exposure. Scientific and bipartisan political consensus exists that the arsenic standard should not be less stringent than 10 ppb, and new data suggest additional adverse health effects related to arsenic exposure through drinking water. Congress has failed to reauthorize the Drinking Water State Revolving Fund program to provide reliable funding to promote compliance and reduce the risk of adverse health effects. Congress's recent ad hoc appropriations do not allow long-term planning and ongoing monitoring and maintenance. Investing in water infrastructure will lower health care costs and create American jobs. Delaying necessary upgrades will only increase the costs of improvements over time.

Multiple animal studies for medical chemical defense program in soldier/patient decontamination and drug development on task 85-17: Validation of an analytical method for the detection of soman (GD), mustard (HD), tabun (GA), and VX in wastewater samples. Final report, 13 October 1985-1 January 1989

DOE Office of Scientific and Technical Information (OSTI.GOV)

Joiner, R.L.; Hayes, L.; Rust, W.

1989-05-01

The following report summarizes the development and validation of an analytical method for the analyses of soman (GD), mustard (HD), VX, and tabun (GA) in wastewater. The need for an analytical method that can detect GD, HD, VX, and GA with the necessary sensitivity (< 20 parts per billion (PPB))and selectivity is essential to Medical Research and Evaluation Facility (MREF) operations. The analytical data were generated using liquid-liquid extraction of the wastewater, with the extract being concentrated and analyzed by gas chromatography (GC) methods. The sample preparation and analyses methods were developed in support of ongoing activities within the MREF.more » We have documented the precision and accuracy of the analytical method through an expected working calibration range (3.0 to 60 ppb). The analytical method was statistically evaluated over a range of concentrations to establish a detection limit and quantitation limit for the method. Whenever the true concentration is 8.5 ppb or above, the probability is at least 99.9 percent that the measured concentration will be ppb or above. Thus, 6 ppb could be used as a lower reliability limit for detecting concentrations in excess of 8.5 ppb. In summary, the proposed sample extraction and analyses methods are suitable for quantitative analyses to determine the presence of GD, HD, VX, and GA in wastewater samples. Our findings indicate that we can detect any of these chemical surety materiel (CSM) in water at or below the established U.S. Army Surgeon General's safety levels in drinking water.« less

Lead in drinking water: sampling in primary schools and preschools in south central Kansas.

PubMed

Massey, Anne R; Steele, Janet E

2012-03-01

Studies in Philadelphia, New York City, Houston, Washington, DC, and Greenville, North Carolina, have revealed high lead levels in drinking water. Unlike urban areas, lead levels in drinking water in suburban and rural areas have not been adequately studied. In the study described in this article, drinking water in primary schools and preschools in five suburban and rural south central Kansas towns was sampled to determine if any exceeded the U.S. Environmental Protection Agency (U.S. EPA) guidance level for schools and child care facilities of 20 parts per billion (ppb). The results showed a total of 32.1% of the samples had detectable lead levels and 3.6% exceeded the U.S. EPA guidance level for schools and child care providers of 20 ppb. These results indicate that about one-third of the drinking water consumed by children age six and under in the five suburban and rural south central Kansas towns studied has some lead contamination, exposing these children to both short-term and long-term health risks. The authors suggest a need for increased surveillance of children's drinking water in these facilities.

A Portable Electronic Nose For Hydrazine and Monomethyl Hydrazine Detection

NASA Technical Reports Server (NTRS)

Young, Rebecca C.; Linnell, Bruce R.; Peterson, Barbara V.; Brooks, Kathy B.; Griffin, Tim P.

2004-01-01

The Space Program and military use large quantities Hydrazine (Hz) and monomethyl hydrazine (MMI-I) as rocket propellant. These substances are very toxic and are suspected human carcinogens. The American Conference of Governmental Industrial Hygienist set the threshold limit value to be 10 parts per billion (ppb). Current off-the-shelf portable instruments require 10 to 20 minutes of exposure to detect 10 ppb concentration. This shortcofriing is not acceptable for many operations. A new prototype instrument using a gas sensor array and pattern recognition software technology (i.e., an electronic nose) has demonstrated the ability to identify either Hz or MM}{ and quantify their concentrations at 10 parts per billion in 90 seconds. This paper describes the design of the portable electronic nose (e-nose) instrument, test equipment setup, test protocol, pattern recognition algorithm, concentration estimation method, and laboratory test results.

Atrazine concentrations in stream water and streambed sediment pore water in the St. Joseph and Galien River basins, Michigan and Indiana, May 2001-September 2003

USGS Publications Warehouse

Duris, Joseph W.; Reeves, Howard W.; Kiesler, James L.

2005-01-01

The U.S. Geological Survey (USGS) sampled multiple stream sites across the St. Joseph and Galien River Basins to detect and quantify the herbicide atrazine using a field enzyme-linked immunosorbent assay (ELISA) triazine test. In May 2001, July 2001, April 2002, August 2002, August 2003 and September 2003, composite samples were collected across streams at USGS streamflow-gaging stations. Concentrations and instantaneous loading for atrazine sampled in stream water throughout the St. Joseph River and Galien River Basins in Michigan and Indiana ranged from nondetection (< 0.05 part per billion (ppb)) with an associated load less than 0.001 kilogram per day (kg/d) to 6 ppb and a maximum load of 10 kg/d. Atrazine concentrations were highest in May 2001 just after the planting season. The lowest concentration was found in April 2002 just before planting. Atrazine concentrations in streambed-sediment pore water were not spatially connected with atrazine concentrations in stream-water samples. This study showed that atrazine concentrations were elevated from May to July in the St. Joseph and Galien River Basins. At many sites, concentrations exceeded the level that has been shown to feminize frog populations (0.2 ppb). There were 8 sites where concentrations exceeded 0.2 ppb atrazine in May 2001 and July 2001.

Hydrology and water quality of the Upper Three Runs Aquifer in the vicinity of the Gibson Road Landfill, Fort Gordon, Georgia, June-November 1999

USGS Publications Warehouse

Priest, Sherlyn; McSwain, Kristen Bukowski

2002-01-01

Fort Gordon military installation, a U.S. Department of the Army facility, is located in east-central Georgia southwest of Augusta. The military base operates a three-phase unlined landfill?Gibson Road Landfill? to store a variety of wastes. Phases I and II stored only household wastes, and these phases were discontinued during the mid?1990s. Fort Gordon currently (1999) operates Phase III of the landfill that stores only construction and demolition debris. Water-quality monitoring detected selected trace elements and organic compounds exceeding the maximum contaminant levels of the U.S. Environmental Protection Agency, National Primary Drinking Water Standards. The selected trace elements and organic compounds detected showed that contamination of ground water had occurred in the vicinity of the landfill. In 1999, the U.S. Geological Survey, in cooperation with the Environmental and Natural Resources Management Office of the U.S. Army Signal Center and Fort Gordon, Georgia, began an assessment of the hydrogeology and water quality in shallow ground water in the vicinity of the Gibson Road Landfill to delineate the extent of a ground-water contamination plume in the vicinity of the landfill. Hydrogeologic units in the Augusta area include the Upper Three Runs aquifer, the Gordon aquifer, the Millers Pond aquifer, and the Dublin aquifer. Only the shallowest aquifer, Upper Three Runs, was penetrated during this study. The Upper Three Runs aquifer is composed of sediments of the Barnwell Group. Mostly, these sediments are highly permeable fine to medium, well-sorted sand with lenses of clay. Ground-water flow is from northwest to southeast and generally was unaffected by seasonal variation during the period of study (June?November 1999). Water-table altitudes in the landfill area for the study period ranged from 394 feet (ft) to 445 ft above sea level. Ground-water samples analyzed for organic compounds and selected trace elements by a U. S. Environmental Protection Agency (USEPA) approved statistical test revealed that increases in contaminant concentrations above the detection limits had occurred during March and September 1999 in five wells?one of which is located upgradient. These organic compounds, respective increases in concentration, and the wells in which they were detected are: methylene chloride?wells 28AA29 (24 parts per billion [ppb] and 46 ppb), 28AA30 (86 ppb and 130 ppb), and 28AA31 (240 ppb and 140 ppb); 1,1-dichloroethene?well 28AA31 (10 ppb and 5.7 ppb); 1,1-dichloroethane? wells 28AA30 (81 ppb and 140 ppb) and 28AA31 (200 ppb and 130 ppb); and 1,1,1-trichloroethane?well 28AA31 (61 ppb and 37 ppb). Although in some wells the concentration decreased from March to September, the median concentrations were still higher in certain groups. Trace element compounds, their respective increases in concentration, and the wells in which they were detected are: chromium?well 28AA30 (1,190 ppb), vanadium?well 28AA30 (104 ppb); barium?wells 28AA27 (42.2 ppb) and 28AA32 (140 ppb), and beryllium?well 28AA30 (6.3 ppb). These increases occurred in September, with the exception of chromium in well 28AA30, which occurred in March. Although a statistical test indicated increases in contaminant concentrations had occurred, water from wells 28AA27, 28AA30, 28AA31, and 28AA32 had a decrease in contaminant concentrations from February 1998 to September 1999. U.S. Environmental Protection Agency, National Primary Drinking Water Regulations Maximum Contaminant Levels (PMCLs), formerly (MCLs) were exceeded in water from four wells for organic compounds and in five wells by selected trace elements during the February 1998, March 1999, and September 1999 sampling periods. The concentrations for the following organic compounds and the associated wells are: methylene chloride (PMCL is 5 ppb)?wells 28AA27 (February, 37 ppb; March, 24 ppb; and September, 9.6 ppb), 28AA29 (February, 20 ppb; March, 24 ppb; and September, 46 ppb), 28AA

Relationship between the concentration of volatile sulphur compound and periodontal disease severity in Nigerian young adults

PubMed Central

Ehizele, Adebola O.; Ojehanon, Patrick I.

2013-01-01

Background: The aim of this study was to determine the relationship between the concentration of volatile sulphur compounds (VSC) in mouth air and the severity of periodontal diseases in young adults. Materials and Methods: A total of 400 subjects were studied. Estimation of periodontal disease severity was done using the basic periodontal examination (BPE) and the baseline measurement of the concentration of VSC in the mouth air of the subjects was done objectively using the Halimeter®. Result: The mean concentration of VSC for the group with BPE code 0 was 91.0 ± 5.9 parts per billion (ppb), 156.4 ± 9.4 ppb for BPE code 1, 275.2 ± 38.5 ppb for BPE code 2, 353.5 ± 72.3 ppb for BPE code 3, and 587.0 ± 2.1 ppb for BPE code 4 (P = 0.001). Majority (79.0%) of the subjects with BPE code 0 had concentration of VSC <181 ppb. Sixty-two (54.9%) with BPE code 1 had concentration of VSC <181 ppb, 34% with BPE code 2 had concentration of VSC <181 ppb and 42.9% with BPE code 3 had concentration of VSC <181 ppb. Only 6.5% of the subjects with BPE code 0 had VSC concentration >250 ppb, whereas all (100%) of those with BPE code 4 had VSC concentration >250 ppb (P = 0.001). Conclusion: It was concluded that a relationship exists between the periodontal pocket depth and the concentration of VCS in mouth air of young adults. PMID:23901175

Relationship between the concentration of volatile sulphur compound and periodontal disease severity in Nigerian young adults.

PubMed

Ehizele, Adebola O; Ojehanon, Patrick I

2013-05-01

The aim of this study was to determine the relationship between the concentration of volatile sulphur compounds (VSC) in mouth air and the severity of periodontal diseases in young adults. A total of 400 subjects were studied. Estimation of periodontal disease severity was done using the basic periodontal examination (BPE) and the baseline measurement of the concentration of VSC in the mouth air of the subjects was done objectively using the Halimeter(®). The mean concentration of VSC for the group with BPE code 0 was 91.0 ± 5.9 parts per billion (ppb), 156.4 ± 9.4 ppb for BPE code 1, 275.2 ± 38.5 ppb for BPE code 2, 353.5 ± 72.3 ppb for BPE code 3, and 587.0 ± 2.1 ppb for BPE code 4 (P = 0.001). Majority (79.0%) of the subjects with BPE code 0 had concentration of VSC <181 ppb. Sixty-two (54.9%) with BPE code 1 had concentration of VSC <181 ppb, 34% with BPE code 2 had concentration of VSC <181 ppb and 42.9% with BPE code 3 had concentration of VSC <181 ppb. Only 6.5% of the subjects with BPE code 0 had VSC concentration >250 ppb, whereas all (100%) of those with BPE code 4 had VSC concentration >250 ppb (P = 0.001). It was concluded that a relationship exists between the periodontal pocket depth and the concentration of VCS in mouth air of young adults.

Determination of ammonia in ethylene using ion mobility spectrometry

NASA Technical Reports Server (NTRS)

Cross, J. H.; Limero, T. F.; Lane, J. L.; Wang, F.

1997-01-01

A simple procedure to analyze ammonia in ethylene by ion mobility spectrometry is described. The spectrometer is operated with a silane polymer membrane., 63Ni ion source, H+ (H2O)n reactant ion, and nitrogen drift and source gas. Ethylene containing parts per billion (ppb) (v/v) concentrations of ammonia is pulled across the membrane and diffuses into the spectrometer. Preconcentration or preseparation is unnecessary, because the ethylene in the spectrometer has no noticeable effect on the analytical results. Ethylene does not polymerize in the radioactive source. Ethylene's flammability is negated by the nitrogen inside the spectrometer. Response to ammonia concentrations between 200 ppb and 1.5 ppm is near linear, and a detection limit of 25 ppb is calculated.

Sub-ppb, Autonomous, Real-time Detection of VOCs with iCRDS

NASA Astrophysics Data System (ADS)

Leen, J.; Gupta, M.; Baer, D. S.

2013-12-01

The continuous, real-time detection of sub-parts-per-billion (ppb) concentrations of volatile organic compounds (VOCs) such as trichloroethylene (TCE) and tetrachloroethylene (PCE) remains difficult, time consuming and expensive. In particular, short term exposure spikes and diurnal variations are difficult or impossible to detect with traditional TO-15 measurements. We present laboratory and field performance data from an instrument based on incoherent cavity ringdown spectroscopy (iCRDS) that operates in the mid-infrared (bands from 860-1060 cm-1 or 970-1280 cm-1) and is capable of detecting a broad range of VOCs, in situ, continuously and autonomously. We have demonstrated the measurement of TCE in zero air with a precision of 0.17 ppb (1σ in 4 minutes). PCE was measured with a precision of 0.15 ppb (1σ in 4 minutes). Both of these measured precisions exceed the EPA's commercial building action limit, which for TCE is 0.92 ppb (5 μg/m3) and for PCE is 0.29 ppb (2 μg/m3). Additionally, the instrument is capable of precisely measuring and quantifying BTEX compounds (benzene, toluene, ethylbenzene, xylene), including differentiation of xylene isomers. We have demonstrated the accurate, interference free measurement of Mountain View, California air doped with TCE concentrations ranging from 4.22 ppb (22.8 μg/m3) to 17.74 ppb (96 μg/m3) with a precision of 1.42 ppb (1σ in 4 minutes). Mountain View, California air doped with 10.83 ppb of PCE (74.0 μg/m3) was measured with a precision of 0.54 ppb (1σ in 4 minutes). Finally, the instrument was deployed to the Superfund site at Moffett Naval Air Station in Mountain View, California where contaminated ground water results in vapor intrusion of TCE and PCE. For two weeks, the instrument operated continuously and autonomously, successfully measuring TCE and PCE concentrations in both the breathing zone and steam tunnel air. TCE concentrations in the breathing zone averaged 0.186 × 0.669 ppb while tunnel air averaged 17.38 × 4.96 ppb, in excellent agreement with previous TO-15 8 hr averages. PCE concentrations in the breathing zone averaged 0.063 × 0.270 ppb while tunnel air averaged 0.755 × 0.359 ppb, again, in excellent agreement with previous TO-15 8 hr averages. The iCRDS instrument has shown the ability to continuously and autonomously measure sub-ppb levels of toxic VOCs in the field, offering an unprecedented picture of the short term dynamics associated with vapor intrusion and ground water pollution.

Acute effects of aflatoxin on northern bobwhites (Colinus virginianus).

PubMed

Moore, Deana L; Henke, Scott E; Fedynich, Alan M; Laurenz, Jamie C; Morgan, Robert

2013-07-01

Aflatoxin is a widely occurring and harmful mycotoxin produced by strains of Aspergillus spp. growing on vegetable matter. We investigated the concentration of aflatoxin needed to impair normal physiologic responses and induce acute morbidity and mortality in Northern Bobwhites (Colinus virginianus). Ten wild-caught adult bobwhites (five males and five females) from southern Texas were randomly assigned to each treatment group (0, 100, 500, 1,000, and 2,000 parts per billion (ppb) aflatoxin; n=50). We orally administered 100 μL of aflatoxin, derived from Aspergillus flavus, once per week for 4 wk and monitored bird mass, daily feed consumption, liver histology, and blood chemistries. An in vitro white blood cell proliferation test was conducted using spleen tissue to determine the effect of aflatoxin on the immune system. There was no mortality in the control groups, whereas mortalities occurred in all treatment groups except in the 100 ppb aflatoxin treatment. Immunosuppression, reduction in gamma-globulin, glucose, and gamma-glutamyltransferase blood levels, and abnormal liver histology were observed in aflatoxin-exposed quail. Blood chemistry indicated cellular damage to the liver and kidneys. We concluded that short-term, acute doses of aflatoxin as low as 100 ppb can be detrimental to the health of Northern Bobwhites.

The Amino Acid Composition of the Sutter's Mill Carbonaceous Chondrite

NASA Technical Reports Server (NTRS)

Glavin, D. P.; Burton, A. S.; Elsila, J. E.; Dworkin, J. P.; Yin, Q. Z.; Cooper, G.; Jenniskens, P.

2012-01-01

In contrast to the Murchison meteorite which had a complex distribution of amino acids with a total C2 to Cs amino acid abundance of approx.14,000 parts-per-billion (ppb) [2], the Sutters Mill meteorite was found to be highly depleted in amino acids. Much lower abundances (approx.30 to 180 ppb) of glycine, beta-alanine, L-alanine and L-serine were detected in SM2 above procedural blank levels indicating that this meteorite sample experienced only minimal terrestrial amino acid contamination after its fall to Earth. Carbon isotope measurements will be necessary to establish the origin of glycine and beta-alanine in SM2. Other non-protein amino acids that are rare on Earth, yet commonly found in other CM meteorites such as aaminoisobutyric acid (alpha-AIB) and isovaline, were not identified in SM2. However, traces of beta-AIB (approx.1 ppb) were detected in SM2 and could be" extraterrestrial in origin. The low abundances of amino acids in the Sutter's Mill meteorite is consistent with mineralogical evidence that at least some parts of the Sutter's Mill meteorite parent body experienced extensive aqueous and/or thermal alteration.

A Gas Chromatograph/Mass Spectrometer System for UltraLow-Emission Combustor Exhaust Studies

NASA Technical Reports Server (NTRS)

Brabbs, Theodore A.; Wey, Chowen Chou

1996-01-01

A gas chromatograph (GC)/mass spectrometer (MS) system that allows the speciation of unburnt hydrocarbons in the combustor exhaust has been developed at the NASA Lewis Research Center. Combustion gas samples are withdrawn through a water-cooled sampling probe which, when not in use, is protected from contamination by a high-pressure nitrogen purge. The sample line and its connecting lines, filters, and valves are all ultraclean and are heated to avoid condensation. The system has resolution to the parts-per-billion (ppb) level.

All-fiber gas sensor with intracavity photothermal spectroscopy.

PubMed

Zhao, Yan; Jin, Wei; Lin, Yuechuan; Yang, Fan; Ho, Hoi Lut

2018-04-01

We present an all-fiber intracavity photothermal (IC-PT) spectroscopic gas sensor with a hollow-core photonic bandgap fiber (HC-PBF) gas cell. The gas cell is placed inside a fiber-ring laser cavity to achieve higher laser light intensity in the hollow core and hence higher PT modulation signal. An experiment with a 0.62-m-long HC-PBF gas cell demonstrated a noise equivalent concentration of 176 ppb acetylene. Theoretical modeling shows that the IC-PT sensor has the potential of achieving sub-ppb (parts-per-billion) acetylene detection sensitivity.

Environmental monitoring of carbaryl applied in urban areas to control the glassy-winged sharpshooter in California.

PubMed

Walters, Johanna; Goh, Kean S; Li, Linying; Feng, Hsiao; Hernandez, Jorge; White, Jane

2003-03-01

Carbaryl insecticide was applied by ground spray to plants in urban areas to control a serious insect pest the glassy-winged sharpshooter, Homalodisca coagulata (Say), newly introduced in California. To assure there are no adverse impacts to human health and the environment from the carbaryl applications, carbaryl was monitored in tank mixtures, air, surface water, foliage and backyard fruits and vegetables. Results from the five urban areas - Porterville, Fresno, Rancho Cordova, Brentwood and Chico - showed there were no significant human exposures or impacts on the environment. Spray tank concentrations ranged from 0.1-0.32%. Carbaryl concentrations in air ranged from none detected to 1.12 microg m(-3), well below the interim health screening level in air of 51.7 microg m(-3). There were three detections of carbaryl in surface water near application sites: 0.125 ppb (parts per billion) from a water treatment basin; 6.94 ppb from a gold fish pond; and 1737 ppb in a rain runoff sample collected from a drain adjacent to a sprayed site. The foliar dislodgeable residues ranged from 1.54-7.12 microg cm(-2), comparable to levels reported for safe reentry of 2.4 to 5.6 microg cm(-2) for citrus. Carbaryl concentrations in fruits and vegetables ranged from no detectable amounts to 7.56 ppm, which were below the U.S. EPA tolerance, allowable residue of 10 ppm.

Remote monitoring of sub ppb levels of vinyl chloride, dichloroethylene and trichloroethylene via modem operated automated GC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Linenberg, A.; Lander, N.J.

1994-12-31

The need for remote monitoring of certain compounds in a sparsely populated area with limited user assistance led to the development and manufacture of a self contained, portable gas chromatography with the appropriate software. Part per billion levels of vinyl chloride, cis 1,2 dichloroethylene and trichloroethylene were detected in air using a trap for preconcentration of the compounds. The units were continuously calibrated with certified standards from Scott Specialty Gases, which in one case was 1 part per billion of the aforementioned compounds. The entire operation of the units, including monitoring instrument responses, changing operating parameters, data transfer, data reviewmore » and data reporting was done entirely on a remote basis from approximately 600 miles away using a remote computer with a modem and remote operating software. The entire system concept promises the availability of highly sensitive remote monitoring in sparsely populated areas for long periods of time.« less

Exhaled nitric oxide in paediatric asthma and cystic fibrosis.

PubMed Central

Lundberg, J O; Nordvall, S L; Weitzberg, E; Kollberg, H; Alving, K

1996-01-01

Nitric oxide (NO) is present in exhaled air of humans. This NO is mostly produced in the upper airways, whereas basal NO excretion in the lower airways is low. Children with Kartagener's syndrome have an almost total lack of NO in nasally derived air, whereas adult asthmatics have increased NO in orally exhaled air. NO excretion was measured in the nasal cavity and in orally exhaled air in 19 healthy children, in 36 age matched subjects with asthma, and in eight children with cystic fibrosis. NO levels in orally exhaled air were similar in controls and in children with cystic fibrosis, at 4.8 (SD 1.2) v 5.8 (0.8) parts per billion (ppb), but were increased in asthmatic children who were untreated or were being treated only with low doses of inhaled steroids (13.8 (2.5) ppb). Nasal NO levels were reduced by about 70% in children with cystic fibrosis compared to controls and asthmatics. Measurements of airway NO release in different parts of the airways may be useful in non-invasive diagnosis and monitoring of inflammatory airway diseases. PMID:8984919

Detection of singly- and doubly-charged quaternary ammonium drugs in equine urine by liquid chromatography/tandem mass spectrometry.

PubMed

Ho, Emmie N M; Kwok, W H; Wong, April S Y; Wan, Terence S M

2012-01-13

Quaternary ammonium drugs (QADs) are anticholinergic agents some of which are known to have been abused or misused in equine sports. A recent review of literature shows that the screening methods reported thus far for QADs mainly cover singly-charged QADs. Doubly-charged QADs are extremely polar substances which are difficult to be extracted and poorly retained on reversed-phase columns. It would be ideal if a comprehensive method can be developed which can detect both singly- and doubly-charged QADs. This paper describes an efficient liquid chromatography/tandem mass spectrometry (LC/MS/MS) method for the simultaneous detection and confirmation of 38 singly- and doubly-charged QADs at sub-parts-per-billion (ppb) to low-ppb levels in equine urine after solid-phase extraction. Quaternary ammonium drugs were extracted from equine urine by solid-phase extraction (SPE) using an ISOLUTE(®) CBA SPE column and analysed by LC/MS/MS in the positive electrospray ionisation mode. Separation of the 38 QADs was achieved on a polar group embedded C18 LC column with a mixture of aqueous ammonium formate (pH 3.0, 10 mM) and acetonitrile as the mobile phase. Detection and confirmation of the 38 QADs at sub-ppb to low-ppb levels in equine urine could be achieved within 16 min using selected reaction monitoring (SRM). Matrix interference of the target transitions at the expected retention times was not observed. Other method validation data, including precision and recovery, were acceptable. The method was successfully applied to the analyses of drug-administration samples. Copyright © 2011 Elsevier B.V. All rights reserved.

21 CFR 556.741 - Tripelennamine.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.741 Tripelennamine. A tolerance of 200 parts per billion (ppb) is...

21 CFR 556.741 - Tripelennamine.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.741 Tripelennamine. A tolerance of 200 parts per billion (ppb) is...

21 CFR 556.741 - Tripelennamine.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.741 Tripelennamine. A tolerance of 200 parts per billion (ppb) is...

21 CFR 556.741 - Tripelennamine.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.741 Tripelennamine. A tolerance of 200 parts per billion (ppb) is...

21 CFR 556.741 - Tripelennamine.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS TOLERANCES FOR RESIDUES OF NEW ANIMAL DRUGS IN FOOD Specific Tolerances for Residues of New Animal Drugs § 556.741 Tripelennamine. A tolerance of 200 parts per billion (ppb) is...

ELECTROCHEMICAL TREATMENT AND RECYCLING OF SPENT PERCHLORATE-CONTAMINATED ION-EXCHANGE REGENERATION BRINE - PHASE I

EPA Science Inventory

Eltron Research & Development, Inc. (Eltron) proposes to develop an ion-selective, polymer membrane electrode capable of detecting perchlorate in water at low parts per billion (ppb) concentrations. With the discovery of perchlorate contamination in an increasing number of...

Atmospheric Carbon Monoxide Mixing Ratios NOAA Climate Monitoring and Diagnostics Laboratory Cooperative Air Sampling Network (1988-1993) (DB1011)

DOE Data Explorer

Novelli, P. C.; Masarie, K. A.

1994-01-01

Individual site files provide CO mixing ratios in parts per billion (ppb) (ppb = parts in 109 by mole fraction) based on measurements from the NOAA/CMDL Cooperative Air Sampling Network beginning 1988. Data are provided through June 1993 for stations at which the first sample was collected before July 1991. All samples were analyzed for CO at the NOAA/CMDL laboratory in Boulder by gas chromatography with mercuric oxide reduction detection, and all measurements are referenced to the CMDL CO scale (Novelli et al., 1991, Novelli et al., 1994).

Organic cleanliness of the Mars Science Laboratory sample transfer chain.

PubMed

Blakkolb, B; Logan, C; Jandura, L; Okon, A; Anderson, M; Katz, I; Aveni, G; Brown, K; Chung, S; Ferraro, N; Limonadi, D; Melko, J; Mennella, J; Yavrouian, A

2014-07-01

One of the primary science goals of the Mars Science Laboratory (MSL) Rover, Curiosity, is the detection of organics in Mars rock and regolith. To achieve this, the Curiosity rover includes a robotic sampling system that acquires rock and regolith samples and delivers it to the Sample Analysis at Mars (SAM) instrument on board the rover. In order to provide confidence that any significant organics detection result was Martian and not terrestrial in origin, a requirement was levied on the flight system (i.e., all sources minus the SAM instrument) to impart no more than 36 parts per billion (ppb by weight) of total reduced carbon terrestrial contamination to any sample transferred to the SAM instrument. This very clean level was achieved by a combination of a rigorous contamination control program on the project, and then using the first collected samples for a "dilution cleaning" campaign of the sample chain prior to delivering a sample to the SAM instrument. Direct cleanliness assays of the sample-contacting and other Flight System surfaces during pre-launch processing were used as inputs to determine the number of dilution cleaning samples needed once on Mars, to enable delivery of suitably clean samples to the SAM experiment. Taking into account contaminant redistribution during launch thorough landing of the MSL on Mars, the amount of residue present on the sampling hardware prior to the time of first dilution cleaning sample acquisition was estimated to be 60 ng/cm(2) on exposed outer surfaces of the sampling hardware and 20 ng/cm(2) on internal sample contacting surfaces; residues consisting mainly of aliphatic hydrocarbons and esters. After three dilution cleaning samples, estimated in-sample contamination level for the first regolith sample delivered to the SAM instrument at the Gale Crater "Rocknest" site was bounded at ≤10 ppb total organic carbon. A Project decision to forego ejecting the dilution cleaning sample and instead transfer the first drill-acquired sample at the "John Klein" site to SAM resulted in an estimated level of terrestrial contamination of ≤430 ppb. The estimated terrestrial contamination for portions from the second drill-acquired sample, at Cumberland, was ≤69 ppb; the estimate for a future, third, drilled sample is ≤38 ppb. These levels are comparable in magnitude to the SAM instrument blanks at the nanomole level (as chlorohydrocarbon).

Room Temperature ppb Level Chlorine Gas Sensor Based on Copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine Films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bedi, R. K.; Saini, Rajan; Mahajan, Aman

2010-12-01

Spin coating technique has been used to fabricate room temperature chlorine gas sensor based on copper (II) 1, 4, 8, 11, 15, 18, 22, 25-octabutoxy-29 H, 31 H-phthalocyanine (CuPc(OBu){sub 8}) films. Gas sensor shows a response of 185% to few parts per billion level of Cl{sub 2} gas with response time of 9.5 minutes at room temperature. The interactions between sensor and analytes followed first order kinetics with rate constant 0.01{<=}k{<=}0.02. The chemiresistive sensor showed very good stability at room temperature over a long period of time.

Environmental characterization of a coffee processing workplace with obliterative bronchiolitis in former workers

PubMed Central

Duling, Matthew G.; LeBouf, Ryan F.; Cox-Ganser, Jean M.; Kreiss, Kathleen; Martin, Stephen B.; Bailey, Rachel L.

2018-01-01

Obliterative bronchiolitis in five former coffee processing employees at a single workplace prompted an exposure study of current workers. Exposure characterization was performed by observing processes, assessing the ventilation system and pressure relationships, analyzing headspace of flavoring samples, and collecting and analyzing personal breathing zone and area air samples for diacetyl and 2,3-pentanedione vapors and total inhalable dust by work area and job title. Mean airborne concentrations were calculated using the minimum variance unbiased estimator of the arithmetic mean. Workers in the grinding/packaging area for unflavored coffee had the highest mean diacetyl exposures, with personal concentrations averaging 93 parts per billion (ppb). This area was under positive pressure with respect to flavored coffee production (mean personal diacetyl levels of 80 ppb). The 2,3-pentanedione exposures were highest in the flavoring room with mean personal exposures of 122 ppb, followed by exposures in the unflavored coffee grinding/packaging area (53 ppb). Peak 15-min airborne concentrations of 14,300 ppb diacetyl and 13,800 ppb 2,3-pentanedione were measured at a small open hatch in the lid of a hopper containing ground unflavored coffee on the mezzanine over the grinding/packaging area. Three out of the four bulk coffee flavorings tested had at least a factor of two higher 2,3-pentanedione than diacetyl headspace measurements. At a coffee processing facility producing both unflavored and flavored coffee, we found the grinding and packaging of unflavored coffee generate simultaneous exposures to diacetyl and 2,3-pentanedione that were well in excess of the NIOSH proposed RELs and similar in magnitude to those in the areas using a flavoring substitute for diacetyl. These findings require physicians to be alert for obliterative bronchiolitis and employers, government, and public health consultants to assess the similarities and differences across the industry to motivate preventive intervention where indicated by exposures above the proposed RELs for diacetyl and 2,3-pentanedione. PMID:27105025

Airborne Fraunhofer line discriminator (FLD) luminescence imaging systems and its application to exploration problems

USGS Publications Warehouse

Watson, Robert D.; Theisen, Arnold F.; Hemphill, William R.; Barringer, Anthony R.

1980-01-01

Experiments with an imaging airborne Fraunhofer line discriminator (FLD) are being conducted to establish the feasibility of delineating the areal extent of luminescent materials on the earth's surface from aircraft and spacecraft. All luminescence measurements are related to a standard set of conditions with rhodamine wt dye used as a reference standard. The FLD has a minimum detectable rhodamine wt concentration of 0.1 parts per billion (ppb) at a signal-to-noise ratio of 5.0. Luminescence, when expressed in a signal-to-noise ratio (R) is related to equivalent ppb rhodamine wt through the relationship ppb=(0.1R-0.4). Luminescent materials imaged from an aircraft altitude of approximately 2400 m above terrain include fluorite in association with molybdenum, Pinenut Mountains, Nevada (R=62.0); mineralized playas, Claunch, New Mexico (R=960.0); uranium and vanadium-bearing outcrops, Big Indian Valley, Utah (R=105.0); uranophane sandstones, Sandia Mountains, New Mexico (R=60.0); phosphate outcrops, Pine Mountain, California (R=76.0); and marine oil slicks, Santa Barbara Channel, California (R=24.0). Correlation between the amount of fluorite in the rocks and soils of the Pinenut Mountains and luminescence, measured by the FLD, is as high as 0.88 at the 95 percent confidence level.

7 CFR 996.11 - Negative aflatoxin content.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 8 2013-01-01 2013-01-01 false Negative aflatoxin content. 996.11 Section 996.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING... aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that have...

7 CFR 996.11 - Negative aflatoxin content.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 8 2014-01-01 2014-01-01 false Negative aflatoxin content. 996.11 Section 996.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (MARKETING... aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that have...

7 CFR 996.11 - Negative aflatoxin content.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 8 2012-01-01 2012-01-01 false Negative aflatoxin content. 996.11 Section 996.11 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Marketing... aflatoxin content. Negative aflatoxin content means 15 parts per billion (ppb) or less for peanuts that have...

DETERMINATION OF 3,5,6-TRICHLORO-2-PYRIDINOL (TCP) BY ELISA

EPA Science Inventory

A sensitive, competitive enzyme-linked immunosorbent assay (ELISA) for 3,5,6-trichloro-2pyridinol (TCP) has been developed to quantitate parts per billion (ppb) amounts of the analyte in urine. TCP is a major metabolite and environmental degradation product of the insecticide c...

Mid-term changes in blood metal ion levels after Articular Surface Replacement arthroplasty of the hip.

PubMed

Galea, V P; Laaksonen, I; Matuszak, S J; Connelly, J W; Muratoglu, O; Malchau, H

2017-04-01

Our first aim was to determine whether there are significant changes in the level of metal ions in the blood at mid-term follow-up, in patients with an Articular Surface Replacement (ASR) arthroplasty. Secondly, we sought to identify risk factors for any increases. The study involved 435 patients who underwent unilateral, metal-on-metal (MoM) hip resurfacing (HRA) or total hip arthroplasty (THA). These patients all had one measurement of the level of metal ions in the blood before seven years had passed post-operatively (early evaluation) and one after seven years had passed post-operatively (mid-term evaluation). Changes in ion levels were tested using a Wilcoxon signed-rank test. We identified subgroups at the highest risk of increase using a multivariable linear logistic regression model. There were significant increases in the levels of metal ions for patients who underwent both MoM HRA (Chromium (Cr): 0.5 parts per billion (ppb); Cobalt (Co): 1.1 ppb) and MoM THA (Cr: 0.5 ppb; Co: 0.7 ppb). In a multivariable model considering MoM HRAs, the change in the levels of metal ions was influenced by female gender (Co: Odds Ratio (OR) 1.42; p = 0.002 and Cr: OR 1.08; p = 0.006). The change was found to be irrespective of the initial level for the MoM HRAs, whereas there was a negative relationship between the initial level and the change in the level for those with a MoM THA (Co: OR -0.43; p < 0.001 and Cr: OR -0.14; p = 0.033). The levels of metal ions in the blood increase significantly over the period until mid-term follow-up in patients with both a MoM HRA and those with a MoM THA. We recommend that the levels of metal ions be measured most frequently for women with a MoM HRA. While those with a MoM THA appear to stabilise at a certain level, the accuracy of this trend is not yet clear. Vigilant follow-up is still recommended. Cite this article: Bone Joint J 2017;99-B(4 Supple B):33-40. ©2017 Galea et al.

Arsenic in Drinking Water--The Silent Killer

ERIC Educational Resources Information Center

Wajrak, Magdalena

2011-01-01

Natural arsenic salts are present in all waters, with natural concentrations of less than 10 parts per billion (ppb). Unfortunately, there is an increasing number of countries where toxic arsenic compounds in groundwater, which is used for drinking and irrigation, have been detected at concentrations above the World Health Organization's…

CAIRPOL CAIRCLIP NM-VOC

EPA Science Inventory

The CairPol CairClip O3-NO2 is a lightweight, portable sensor for measuring ozone (O3) and nitrogen dioxide (NO2) in parts per billion (ppb) or micrograms per cubic meter (µg/m3) in applications such as personal exposure and indoor and outdoor air quality monitoring. It uses a mi...

USEPA ARSENIC REMOVAL FULL-SCALE DEMONSTRATION PROGRAM

EPA Science Inventory

On October 31, 2001 EPA announced that the final standard for arsenic in drinking water of ten parts per billion (10 ppb) would become effective on February 22, 2002 without any further action by EPA. This means that the standard will be implemented as specified in the January 22...

The Spectral and Chemical Measurement of Pollutants on Snow Near South Pole, Antarctica

NASA Technical Reports Server (NTRS)

Casey, K. A.; Kaspari, S. D.; Skiles, S. M.; Kreutz, K.; Handley, M. J.

2017-01-01

Remote sensing of light-absorbing particles (LAPs), or dark colored impurities, such as black carbon (BC) and dust on snow, is a key remaining challenge in cryospheric surface characterization and application to snow, ice, and climate models. We present a quantitative data set of in situ snow reflectance, measured and modeled albedo, and BC and trace element concentrations from clean to heavily fossil fuel emission contaminated snow near South Pole, Antarctica. Over 380 snow reflectance spectra (350-2500 nm) and 28 surface snow samples were collected at seven distinct sites in the austral summer season of 2014-2015. Snow samples were analyzed for BC concentration via a single particle soot photometer and for trace element concentration via an inductively coupled plasma mass spectrometer. Snow impurity concentrations ranged from 0.14 to 7000 part per billion (ppb) BC, 9.5 to 1200 ppb sulfur, 0.19 to 660 ppb iron, 0.013 to 1.9 ppb chromium, 0.13 to 120 ppb copper, 0.63 to 6.3 ppb zinc, 0.45 to 82 parts per trillion (ppt) arsenic, 0.0028 to 6.1 ppb cadmium, 0.062 to 22 ppb barium, and 0.0044 to 6.2 ppb lead. Broadband visible to shortwave infrared albedo ranged from 0.85 in pristine snow to 0.62 in contaminated snow. LAP radiative forcing, the enhanced surface absorption due to BC and trace elements, spanned from less than 1 W m(exp. -2) for clean snow to approximately 70 W m(exp. -2) for snow with high BC and trace element content. Measured snow reflectance differed from modeled snow albedo due to specific impurity-dependent absorption features, which we recommend be further studied and improved in snow albedo models.

The spectral and chemical measurement of pollutants on snow near South Pole, Antarctica

NASA Astrophysics Data System (ADS)

Casey, K. A.; Kaspari, S. D.; Skiles, S. M.; Kreutz, K.; Handley, M. J.

2017-06-01

Remote sensing of light-absorbing particles (LAPs), or dark colored impurities, such as black carbon (BC) and dust on snow, is a key remaining challenge in cryospheric surface characterization and application to snow, ice, and climate models. We present a quantitative data set of in situ snow reflectance, measured and modeled albedo, and BC and trace element concentrations from clean to heavily fossil fuel emission contaminated snow near South Pole, Antarctica. Over 380 snow reflectance spectra (350-2500 nm) and 28 surface snow samples were collected at seven distinct sites in the austral summer season of 2014-2015. Snow samples were analyzed for BC concentration via a single particle soot photometer and for trace element concentration via an inductively coupled plasma mass spectrometer. Snow impurity concentrations ranged from 0.14 to 7000 part per billion (ppb) BC, 9.5 to 1200 ppb sulfur, 0.19 to 660 ppb iron, 0.013 to 1.9 ppb chromium, 0.13 to 120 ppb copper, 0.63 to 6.3 ppb zinc, 0.45 to 82 parts per trillion (ppt) arsenic, 0.0028 to 6.1 ppb cadmium, 0.062 to 22 ppb barium, and 0.0044 to 6.2 ppb lead. Broadband visible to shortwave infrared albedo ranged from 0.85 in pristine snow to 0.62 in contaminated snow. LAP radiative forcing, the enhanced surface absorption due to BC and trace elements, spanned from <1 W m-2 for clean snow to 70 W m-2 for snow with high BC and trace element content. Measured snow reflectance differed from modeled snow albedo due to specific impurity-dependent absorption features, which we recommend be further studied and improved in snow albedo models.

Electronic Nose: Evaluation of Kamina Prototype Unit

NASA Technical Reports Server (NTRS)

Schattke, Nathan

2001-01-01

The Kamina, Sam and Cyranose electronic nose systems were evaluated and partially trained. Much work was performed on the Kamina as it has the ability to respond to low (less than 10 ppb) concentrations of hydrazine compounds. We were able to tell the difference between Hydrazine (Hz) and Monomethylhydrazine (MMH) in standard clean humid air. We were able to detect MMH in reduced pressure (1/3 atm) at about 250 ppb, however the training set was to far from the real situation to be useful now. Various engineering and usability aspects of both the noses was noted, especially the software. One serious physical engineering flaw was remedied in the Kamina system. A gas flow manifold was created for the Sam system. Different chips were evaluated for the Kamina system. It is still unclear if they can be exchanged without retraining the software.The Sam Detect commercial unit was evaluated for solvent detection and evaluation. It was able to successfully identify some solvents. The Cyranose, was observed and evaluated for two days. It has the ability to detect gasses in the 100 parts per million level but not the 10 parts per billion level. It is very sensitive to humidity changes; there is software to partially handle this.

Colorimetric detection of catalytic reactivity of nanoparticles in complex matrices.

PubMed

Corredor, Charlie; Borysiak, Mark D; Wolfer, Jay; Westerhoff, Paul; Posner, Jonathan D

2015-03-17

There is a need for new methodologies to quickly assess the presence and reactivity of nanoparticles (NPs) in commercial, environmental, and biological samples since current detection techniques require expensive and complex analytical instrumentation. Here, we investigate a simple and portable colorimetric detection assay that assesses the surface reactivity of NPs, which can be used to detect the presence of NPs, in complex matrices (e.g., environmental waters, serum, urine, and in dissolved organic matter) at as low as part per billion (ppb) or ng/mL concentration levels. Surface redox reactivity is a key emerging property related to potential toxicity of NPs with living cells, and is used in our assays as a key surrogate for the presence of NPs and a first tier analytical strategy toward assessing NP exposures. We detect a wide range of metal (e.g., Ag and Au) and oxide (e.g., CeO2, SiO2, VO2) NPs with a diameter range of 5 to 400 nm and multiple capping agents (tannic acid (TA), polyvinylpyrrolidone (PVP), branched polyethylenimine (BPEI), polyethylene glycol (PEG)). This method is sufficiently sensitive (ppb levels) to measure concentrations typically used in toxicological studies, and uses inexpensive, commercially available reagents.

Determination of toxic inorganic elements pollution in ground waters of Kahuta Industrial Triangle Islamabad, Pakistan using inductively coupled plasma mass spectrometry.

PubMed

Kausar, Rubina; Ahmad, Zulfiqar

2009-10-01

The present study deals with the ground water quality assessment in Kahuta Industrial Triangle Islamabad, Pakistan. The objective of the study was to assess ground water quality against the drinking water standards for various toxic inorganic elements. Representative groundwater samples were collected and analyzed in the Water Quality Laboratory of Pakistan Council of Research in Water Resources (PCRWR) at Islamabad, Pakistan. The samples were run on ICP-MS (Inductively coupled plasma mass spectrometry), which has the capability to separate and quantify 70 elements at a time. One of the finding of study is that ICP-MS is a very good tool to analyze broad range of toxic inorganic elements to the level of parts per billion (ppb). World Health Organization drinking water standards shows that these toxic inorganic elements such as heavy metals even at this concentration level (ppb) are injurious to human health. This analysis indicated pollution of various toxic elements including Selenium. Vertical leachate through industrial waste septic tanks is identified as major cause of groundwater pollution in the Industrial Triangle. Monitoring of the septic tanks and groundwater quality in study area is suggested along with remedial measures.

Concentrations of platinum group elements in 122 U.S. coal samples

USGS Publications Warehouse

Oman, C.L.; Finkelman, R.B.; Tewalt, S.J.

1997-01-01

Analysis of more than 13,000 coal samples by semi-quantitative optical emission spectroscopy (OES) indicates that concentrations of the platinum group elements (iridium, palladium, platinum, osmium, rhodium, and ruthenium) are less than 1 ppm in the ash, the limit of detection for this method of analysis. In order to accurately determine the concentration of the platinum group elements (PGE) in coal, additional data were obtained by inductively coupled plasma mass spectroscopy, an analytical method having part-per-billion (ppb) detection limits for these elements. These data indicate that the PGE in coal occur in concentrations on the order of 1 ppb or less.

Ultra-trace analysis of furanic compounds in transformer/rectifier oils with water extraction and high-performance liquid chromatography.

PubMed

Lin, Monica; Lin, Kham; Lin, Amanda; Gras, Ronda; Luong, Jim

2016-07-01

A novel approach for the determination of parts-per-billion level of 5-hydroxymethyl-2-furaldehyde, furfuryl alcohol, furfural, 2-furyl methyl ketone, and 5-methylfurfural in transformer or rectifier oils has been successfully innovated and implemented. Various extraction methods including solid-phase extraction, liquid-liquid extraction using methanol, acetonitrile, and water were studied. Water was by far the most efficient solvent for use as an extraction medium. Separation of the analytes was conducted using a 4.6 mm × 250 mm × 3.5 μm Agilent Zorbax column while detection and quantitation were conducted with a variable wavelength UV detector. Detection limits of all furans were at 1 ppb v/v with linear ranges range from 5 to 1000 ppb v/v with correlation coefficients of 0.997 or better. A relative standard deviation of at most 2.4% at 1000 ppb v/v and 7.3% at 5 ppb v/v and a recovery from 43% to 90% depending on the analyte monitored were obtained. The method was purposely designed to be environmental friendly with water as an extraction medium. Also, the method uses 80% water and 20% acetonitrile with a mere 0.2 mL/min of acetonitrile in an acetonitrile/water mixture as mobile phase. The analytical technique has been demonstrated to be highly reliable with low cost of ownership, suitable for deployment in quality control labs or in regions where available analytical resources and solvents are difficult to procure. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Determination of palladium, platinum and rhodium in geologic materials by fire assay and emission spectrography

USGS Publications Warehouse

Hapfty, J.; Riley, L.B.

1968-01-01

A method is described for the determination of palladium down to 4ppb (parts per billion, 109), platinum down to 10 ppb and rhodium down to 5 ppb in 15 g of sample. Fire-assay techniques are used to preconcentrate the platinum metals into a gold bead, then the bead is dissolved in aqua regia and diluted to volume with 1M hydrochloric acid. The solution is analysed by optical emission spectrography of the residue from 200 ??l of it evaporated on a pair of flat-top graphite electrodes. This method requires much less sample handling than most published methods for these elements. Data are presented for G-1, W-1, and six new standard rocks of the U.S. Geological Survey. The values for palladium in W-1 are in reasonable agreement with previously published data. ?? 1968.

CAIRPOL CAIRCLIP O3-NO2

EPA Science Inventory

The CairPol CairClip O₃-NO₂ is a lightweight, portable sensor for measuring ozone (O₃) and nitrogen dioxide (NO₂) in parts per billion (ppb) or micrograms per cubic meter (µg/m³) in applications such as personal exposure and ...

Metal ion levels and lymphocyte counts: ASR hip resurfacing prosthesis vs. standard THA

PubMed Central

2013-01-01

Background and purpose Wear particles from metal–on–metal arthroplasties are under suspicion for adverse effects both locally and systemically, and the DePuy ASR Hip Resurfacing System (RHA) has above–average failure rates. We compared lymphocyte counts in RHA and total hip arthroplasty (THA) and investigated whether cobalt and chromium ions affected the lymphocyte counts. Method In a randomized controlled trial, we followed 19 RHA patients and 19 THA patients. Lymphocyte subsets and chromium and cobalt ion concentrations were measured at baseline, at 8 weeks, at 6 months, and at 1 and 2 years. Results The T–lymphocyte counts for both implant types declined over the 2–year period. This decline was statistically significant for CD3+CD8+ in the THA group, with a regression coefficient of –0.04 × 109cells/year (95% CI: –0.08 to –0.01). Regression analysis indicated a depressive effect of cobalt ions in particular on T–cells with 2–year whole–blood cobalt regression coefficients for CD3+ of –0.10 (95% CI: –0.16 to –0.04) × 109 cells/parts per billion (ppb), for CD3+CD4+ of –0.06 (–0.09 to –0.03) × 109 cells/ppb, and for CD3+CD8+ of –0.02 (–0.03 to –0.00) × 109 cells/ppb. Interpretation Circulating T–lymphocyte levels may decline after surgery, regardless of implant type. Metal ions—particularly cobalt—may have a general depressive effect on T– and B–lymphocyte levels. Registered with ClinicalTrials.gov under # NCT01113762 PMID:23597114

Quantitative Analysis of Aloins and Aloin-Emodin in Aloe Vera Raw Materials and Finished Products Using High-Performance Liquid Chromatography: Single-Laboratory Validation, First Action 2016.09.

PubMed

Kline, David; Ritruthai, Vicha; Babajanian, Silva; Gao, Quanyin; Ingle, Prashant; Chang, Peter; Swanson, Gary

2017-05-01

A single-laboratory validation study is described for a method of quantitative analysis of aloins (aloins A and B) and aloe-emodin in aloe vera raw materials and finished products. This method used HPLC coupled with UV detection at 380 nm for the aloins and 430 nm for aloe-emodin. The advantage of this test method is that the target analytes are concentrated from the sample matrix (either liquid or solid form) using stepwise liquid-liquid extraction (water-ethyl acetate-methanol), followed by solvent evaporation and reconstitution. This sample preparation process is suitable for different forms of products. The concentrating step for aloins and aloe-emodin has enhanced the method quantitation level to 20 parts per billion (ppb). Reversed-phase chromatography using a 250 × 4.6 mm column under gradient elution conditions was used. Mobile phase A is 0.1% acetic acid in water and mobile phase B is 0.1% acetic acid in acetonitrile. The HPLC run starts with a 20% mobile phase B that reaches 35% at 13 min. From 13 to 30 min, mobile phase B is increased from 35 to 100%. From 30 to 40 min, mobile phase B is changed from 100% back to the initial condition of 20% for re-equilibration. The flow rate is 1 mL/min, with a 100 μL injection volume. Baseline separation (Rs > 2.0) for aloins A and B and aloe-emodin was observed under this chromatographic condition. This test method was validated with raw materials of aloe vera 5× (liquid) and aloe vera 200× (powder) and finished products of aloe concentrate (liquid) and aloe (powder). The linearity of the method was studied from 10 to 500 ppb for aloins A and B and aloe-emodin, with correlation coefficients of 0.999964, 0.999957, and 0.999980, respectively. The test method was proven to be specific, precise, accurate, rugged, and suitable for the intended quantitative analysis of aloins and aloe-emodin in raw materials and finished products. The S/N for aloins A and B and aloe-emodin at 10 ppb level were 12, 10, and 8, respectively, indicating our conservative LOD level at 10 ppb (the typical LOD level S/N is about 3). The S/N for aloins A and B and aloe-emodin at the 20 ppb level were 17, 14, and 16, respectively, indicating our conservative LOQ level at 20 ppb (the typical LOQ level S/N is about 10). The stock standard solution of a mixture of aloins and aloe-emodin and a working standard solution were found to be stable for at least 19 days when stored refrigerated at 2-8°C, with a recovery of 100 ± 5%.

Skin cancer and inorganic arsenic: uncertainty-status of risk.

PubMed

Brown, K G; Guo, H R; Kuo, T L; Greene, H L

1997-02-01

The current U.S. EPA standard for inorganic arsenic in drinking water is 50 ppb (microgram/L), dating to the National Interim Primary Drinking Water Regulation of 1976. The current EPA risk analysis predicts an increased lifetime skin cancer risk on the order of 3 or 4 per 1000 from chronic exposure at that concentration. Revision of the standard to only a few ppb, perhaps even less than 1 ppb, may be indicated by the EPA analysis to reduce the lifetime risk to an acceptable level. The cost to water utilities, and ultimately to their consumers, to conform to such a large reduction in the standard could easily reach several billion dollars, so it is particularly important to assess accurately the current risk and the risk reduction that would be achieved by a lower standard. This article addresses the major sources of uncertainty in the EPA analysis with respect to this objective. Specifically, it focuses on uncertainty and variability in the exposure estimates for the landmark study of Tseng and colleagues in Taiwan, analyzed using a reconstruction of the their exposure data. It is concluded that while the available dataset is suitable to establish the hazard of skin cancer, it is too highly summarized for reliable dose-response assessment. A new epidemiologic study is needed, designed for the requirements of dose-response assessment.

Ozone impedes the ability of a herbivore to find its host

NASA Astrophysics Data System (ADS)

Fuentes, Jose D.; Roulston, T.'ai H.; Zenker, John

2013-03-01

Plant-emitted hydrocarbons mediate several key interactions between plants and insects. They enhance the ability of pollinators and herbivores to locate suitable host plants, and parasitoids to locate herbivores. While plant volatiles provide strong chemical signals, these signals are potentially degraded by exposure to pollutants such as ozone, which has increased in the troposphere and is projected to continue to increase over the coming decades. Despite the potential broad ecological significance of reduced plant signaling effectiveness, few studies have examined behavioral responses of insects to their hosts in polluted environments. Here, we use a laboratory study to test the effect of ozone concentration gradients on the ability of the striped cucumber beetle (Acalymma vittatum) to locate flowers of its host plant, Cucurbita foetidissima. Y-tube experiments showed that ozone mixing ratios below 80 parts per billion (ppb) resulted in beetles moving toward their host plant, but levels above 80 ppb resulted in beetles moving randomly with respect to host location. There was no evidence that beetles avoided polluted air directly. The results show that ozone pollution has great potential to perniciously alter key interactions between plants and animals.

Determination of acidic herbicides in surface water by solid-phase extraction followed by capillary zone electrophoresis.

PubMed

Qin, Weidong; Wei, Hongping; Li, Sam Fong Yau

2002-08-01

A rapid solid-phase extraction-capillary zone electrophoresis (CZE) method for determining 2,4-dichlorophenoxyacetic acid, 4-(2,4-dichlorophenoxy) butyric acid, and 2,4,5-trichlorophenoxyacetic acid in real water samples is described. Factors affecting the recoveries and detection of the targets are investigated. With samples being acidified to pH 2 and salted by sodium sulfate to 2% (w/w), an average recovery of greater than 85% is obtained using ethyl acetate as the eluent on an octadecylsilane-bonded silica cartridge. A running buffer of 5 mM sodium tetraborate in a water-acetonitrile mixture (70:30, v/v) adjusted to pH 9 is employed in the CZE analysis, and the targets can be analyzed within 7 min with good reproducibility and acceptable sensitivity. The method is suitable for detecting herbicide residues of sub-parts-per-billion levels in surface water. A local pond water is analyzed, and the concentrations of 2,4-dichlorophenoxyacetic acid and 4-(2,4-dichlorophenoxy) butyric acid are detected to be 0.27 +/- 0.03 ppb and 0.61 +/- 0.08 ppb, respectively.

Evaluation of Nickel and Chromium Ion Release During Fixed Orthodontic Treatment Using Inductively Coupled Plasma-Mass Spectrometer: An In Vivo Study

PubMed Central

Nayak, Rabindra S; Khanna, Bharti; Pasha, Azam; Vinay, K; Narayan, Anjali; Chaitra, K

2015-01-01

Background: Fixed orthodontic appliances with the use of stainless steel brackets and archwires made of nitinol have a corrosive potential in the oral environment. Nickel and chromium ions released from these appliances act as allergens apart from being cytotoxic, mutagenic and carcinogenic in smaller quantities in the range of nanograms. This study was done to evaluate the release of nickel and chromium ions from orthodontic appliances in the oral cavity using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Materials and Methods: Saliva samples from 30 orthodontic patients undergoing treatment with 0.022″ MBT mechanotherapy were collected prior to commencement of treatment, after initial aligning wires and after 10-12 months of treatment. Salivary nickel and chromium ion concentration was measured in parts per billion (ppb) using ICP-MS. Results: Mean, standard deviation and range were computed for the concentrations of ions obtained. Results analyzed using ANOVA indicated a statistically significant increase of 10.35 ppb in nickel ion concentration and 33.53 ppb in chromium ion concentration after initial alignment. The ionic concentration at the end of 10-12 months of treatment showed a statistically significant increase in of 17.92 ppb for chromium and a statistically insignificant decrease in nickel ion concentration by 1.58 ppb. Pearson’s correlation coefficient showed a positive correlation for an increase in nickel concentration after aligning, but not at the end of 10-12 months. A positive correlation was seen for an increase in chromium ion concentration at both time intervals. Conclusion: Nickel and chromium ion concentration in saliva even though below the recommended daily allowance should not be ignored in light of the new knowledge regarding effects of these ions at the molecular level and the allergic potential. Careful and detailed medical history of allergy is essential. Nickel free alternatives should form an essential part of an orthodontist’s inventory. PMID:26464533

Evaluation of Nickel and Chromium Ion Release During Fixed Orthodontic Treatment Using Inductively Coupled Plasma-Mass Spectrometer: An In Vivo Study.

PubMed

Nayak, Rabindra S; Khanna, Bharti; Pasha, Azam; Vinay, K; Narayan, Anjali; Chaitra, K

2015-08-01

Fixed orthodontic appliances with the use of stainless steel brackets and archwires made of nitinol have a corrosive potential in the oral environment. Nickel and chromium ions released from these appliances act as allergens apart from being cytotoxic, mutagenic and carcinogenic in smaller quantities in the range of nanograms. This study was done to evaluate the release of nickel and chromium ions from orthodontic appliances in the oral cavity using Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Saliva samples from 30 orthodontic patients undergoing treatment with 0.022″ MBT mechanotherapy were collected prior to commencement of treatment, after initial aligning wires and after 10-12 months of treatment. Salivary nickel and chromium ion concentration was measured in parts per billion (ppb) using ICP-MS. Mean, standard deviation and range were computed for the concentrations of ions obtained. Results analyzed using ANOVA indicated a statistically significant increase of 10.35 ppb in nickel ion concentration and 33.53 ppb in chromium ion concentration after initial alignment. The ionic concentration at the end of 10-12 months of treatment showed a statistically significant increase in of 17.92 ppb for chromium and a statistically insignificant decrease in nickel ion concentration by 1.58 ppb. Pearson's correlation coefficient showed a positive correlation for an increase in nickel concentration after aligning, but not at the end of 10-12 months. A positive correlation was seen for an increase in chromium ion concentration at both time intervals. Nickel and chromium ion concentration in saliva even though below the recommended daily allowance should not be ignored in light of the new knowledge regarding effects of these ions at the molecular level and the allergic potential. Careful and detailed medical history of allergy is essential. Nickel free alternatives should form an essential part of an orthodontist's inventory.

Health-Related Benefits of Attaining the 8-Hr Ozone Standard

PubMed Central

Hubbell, Bryan J.; Hallberg, Aaron; McCubbin, Donald R.; Post, Ellen

2005-01-01

During the 2000–2002 time period, between 36 and 56% of ozone monitors each year in the United States failed to meet the current ozone standard of 80 ppb for the fourth highest maximum 8-hr ozone concentration. We estimated the health benefits of attaining the ozone standard at these monitors using the U.S. Environmental Protection Agency’s Environmental Benefits Mapping and Analysis Program. We used health impact functions based on published epidemiologic studies, and valuation functions derived from the economics literature. The estimated health benefits for 2000 and 2001 are similar in magnitude, whereas the results for 2002 are roughly twice that of each of the prior 2 years. The simple average of health impacts across the 3 years includes reductions of 800 premature deaths, 4,500 hospital and emergency department admissions, 900,000 school absences, and > 1 million minor restricted activity days. The simple average of benefits (including premature mortality) across the 3 years is $5.7 billion [90% confidence interval (CI), 0.6–15.0] for the quadratic rollback simulation method and $4.9 billion (90% CI, 0.5–14.0) for the proportional rollback simulation method. Results are sensitive to the form of the standard and to assumptions about background ozone levels. If the form of the standard is based on the first highest maximum 8-hr concentration, impacts are increased by a factor of 2–3. Increasing the assumed hourly background from zero to 40 ppb reduced impacts by 30 and 60% for the proportional and quadratic attainment simulation methods, respectively. PMID:15626651

Production of ozone and reactive oxygen species after welding.

PubMed

Liu, H H; Wu, Y C; Chen, H L

2007-11-01

Many toxic substances including heavy metals, ozone, carbon monoxide, carbon dioxide, and nitrogen oxides are generated during welding. Ozone (O(3)) is a strong oxidant that generates reactive oxygen species (ROS) in tissue, and ambient ROS exposure associated with particles has been determined to cause DNA damage. Ozone is produced within 30 seconds during welding. However, the length of time that O(3) remains in the air after welding is completed (post-welding) is unknown. The current study aimed to assess the distributions of ambient ROS and O(3) before the start of welding (pre-welding), during welding, and after welding. The highest O(3) levels, equal to 195 parts per billion (ppb), appeared during welding. Ozone levels gradually decreased to 60 ppb 10 minutes after the welding was completed. The highest ROS level was found in samples taken during welding, followed by samples taken after the welding was completed. The lowest ROS level was found in samples taken before the welding had started. Ozone and ROS levels were poorly correlated, but a similar trend was found for O(3) and ROS levels in particles (microM/mg). Although particles were not generated after welding, ROS and O(3) still persisted for more than 10 minutes. Meanwhile, because O(3) continues after welding, how long the occupational protective system should be used depends on the welding materials and the methods used. In addition, the relationship between metal fumes and ROS generation during the welding process should be further investigated.

Demonstration of Diesel Engine Air Emissions Reduction Technologies

DTIC Science & Technology

2008-12-01

16 Figure 5. Plots of Cheyenne Mountain Operating Cycle and Reference CBD Driving...Air Act CARB California Air Resources Board CBD Central Business District CCR California Code of Regulations CES Cummins Emissions Solutions CFR...matter ppb parts per billion ppm parts per million PuriNOx Proprietary Water / Diesel Emulsified Fuel RPF robust particulate filter THC total

Ammonia And Ethylene Optrodes For Research On Plant Growth

NASA Technical Reports Server (NTRS)

Zhou, Quan; Tabacco, Mary Beth

1995-01-01

Fiber-optic sensors developed for use in measuring concentrations of ammonia and ethylene near plants during experiments on growth of plants in enclosed environments. Developmental fiber-optic sensors satisfy need to measure concentrations as low as few parts per billion (ppb) and expected to contribute to research on roles of ethylene and ammonia in growth of plants.

Hydrogen cyanide as a biomarker for Pseudomonas aeruginosa in the breath of children with cystic fibrosis.

PubMed

Enderby, Beth; Smith, David; Carroll, W; Lenney, W

2009-02-01

Hydrogen cyanide (HCN) is emitted by Pseudomonas aeruginosa (PA) in vitro. We hypothesized that exhaled HCN could be measured using Selected Ion Flow Tube Mass Spectrometry (SIFT-MS) and that concentrations would be higher in children with cystic fibrosis (CF) and PA infection than in children with asthma. Children aged 7-17 years with CF (n = 16) or asthma (n = 21) attending outpatient clinics provided breath samples between July and December 2007. HCN was measured using the SIFT-MS Profile 3 instrument. FeNO was measured with a Sievers NOA 280i analyzer. Baseline inter-group differences between HCN and FeNO concentrations were compared using the Mann-Whitney U test. Children were invited to re-attend fortnightly. Breath samples, spirometry, growth and clinical status were measured at each visit. There were significant baseline differences in exhaled HCN and FeNO concentrations between the two groups. Children with CF had higher median HCN concentrations than those with asthma: 13.5 parts per billion (ppb) (IQR 8.1-16.5) versus 2.0 ppb (IQR 0.0-4.8) (P < 0.001). Children with CF had lower median FeNO levels compared to children with asthma: 13.4 ppb (IQR 8.9-17.6) versus 57.9 ppb (IQR 34.0-85.7) (P < 0.001). Intra-subject variability was high and significant changes in HCN concentrations were not observed related to changes in lung function or clinical status. This study provides proof of principle that HCN is detectable in the breath of children with CF and is elevated compared to children with asthma. Further studies are required to capture data from acutely unwell children and more accurately delineate responses to treatment. (c) 2009 Wiley-Liss, Inc.

Single aflatoxin contaminated corn kernel analysis with fluorescence hyperspectral image

NASA Astrophysics Data System (ADS)

Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Ononye, Ambrose; Brown, Robert L.; Cleveland, Thomas E.

2010-04-01

Aflatoxins are toxic secondary metabolites of the fungi Aspergillus flavus and Aspergillus parasiticus, among others. Aflatoxin contaminated corn is toxic to domestic animals when ingested in feed and is a known carcinogen associated with liver and lung cancer in humans. Consequently, aflatoxin levels in food and feed are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food and 100 ppb in feed for interstate commerce. Currently, aflatoxin detection and quantification methods are based on analytical tests including thin-layer chromatography (TCL) and high performance liquid chromatography (HPLC). These analytical tests require the destruction of samples, and are costly and time consuming. Thus, the ability to detect aflatoxin in a rapid, nondestructive way is crucial to the grain industry, particularly to corn industry. Hyperspectral imaging technology offers a non-invasive approach toward screening for food safety inspection and quality control based on its spectral signature. The focus of this paper is to classify aflatoxin contaminated single corn kernels using fluorescence hyperspectral imagery. Field inoculated corn kernels were used in the study. Contaminated and control kernels under long wavelength ultraviolet excitation were imaged using a visible near-infrared (VNIR) hyperspectral camera. The imaged kernels were chemically analyzed to provide reference information for image analysis. This paper describes a procedure to process corn kernels located in different images for statistical training and classification. Two classification algorithms, Maximum Likelihood and Binary Encoding, were used to classify each corn kernel into "control" or "contaminated" through pixel classification. The Binary Encoding approach had a slightly better performance with accuracy equals to 87% or 88% when 20 ppb or 100 ppb was used as classification threshold, respectively.

The geographic distribution and economic value of climate change-related ozone health impacts in the United States in 2030.

PubMed

Fann, Neal; Nolte, Christopher G; Dolwick, Patrick; Spero, Tanya L; Brown, Amanda Curry; Phillips, Sharon; Anenberg, Susan

2015-05-01

In this United States-focused analysis we use outputs from two general circulation models (GCMs) driven by different greenhouse gas forcing scenarios as inputs to regional climate and chemical transport models to investigate potential changes in near-term U.S. air quality due to climate change. We conduct multiyear simulations to account for interannual variability and characterize the near-term influence of a changing climate on tropospheric ozone-related health impacts near the year 2030, which is a policy-relevant time frame that is subject to fewer uncertainties than other approaches employed in the literature. We adopt a 2030 emissions inventory that accounts for fully implementing anthropogenic emissions controls required by federal, state, and/or local policies, which is projected to strongly influence future ozone levels. We quantify a comprehensive suite of ozone-related mortality and morbidity impacts including emergency department visits, hospital admissions, acute respiratory symptoms, and lost school days, and estimate the economic value of these impacts. Both GCMs project average daily maximum temperature to increase by 1-4°C and 1-5 ppb increases in daily 8-hr maximum ozone at 2030, though each climate scenario produces ozone levels that vary greatly over space and time. We estimate tens to thousands of additional ozone-related premature deaths and illnesses per year for these two scenarios and calculate an economic burden of these health outcomes of hundreds of millions to tens of billions of U.S. dollars (2010$). Near-term changes to the climate have the potential to greatly affect ground-level ozone. Using a 2030 emission inventory with regional climate fields downscaled from two general circulation models, we project mean temperature increases of 1 to 4°C and climate-driven mean daily 8-hr maximum ozone increases of 1-5 ppb, though each climate scenario produces ozone levels that vary significantly over space and time. These increased ozone levels are estimated to result in tens to thousands of ozone-related premature deaths and illnesses per year and an economic burden of hundreds of millions to tens of billions of U.S. dollars (2010$).

Silica Gel Coated Spherical Micro resonator for Ultra-High Sensitivity Detection of Ammonia Gas Concentration in Air.

PubMed

Mallik, Arun Kumar; Farrell, Gerald; Liu, Dejun; Kavungal, Vishnu; Wu, Qiang; Semenova, Yuliya

2018-01-26

A silica gel coated microsphere resonator is proposed and experimentally demonstrated for measurements of ammonia (NH 3 ) concentration in air with ultra-high sensitivity. The optical properties of the porous silica gel layer change when it is exposed to low (parts per million (ppm)) and even ultra-low (parts per billion (ppb)) concentrations of ammonia vapor, leading to a spectral shift of the WGM resonances in the transmission spectrum of the fiber taper. The experimentally demonstrated sensitivity of the proposed sensor to ammonia is estimated as 34.46 pm/ppm in the low ammonia concentrations range from 4 ppm to 30 ppm using an optical spectrum analyser (OSA), and as 800 pm/ppm in the ultra-low range of ammonia concentrations from 2.5 ppb to 12 ppb using the frequency detuning method, resulting in the lowest detection limit (by two orders of magnitude) reported to date equal to 0.16 ppb of ammonia in air. In addition, the sensor exhibits excellent selectivity to ammonia and very fast response and recovery times measured at 1.5 and 3.6 seconds, respectively. Other attractive features of the proposed sensor are its compact nature, simplicity of fabrication.

Sensing strategies for toxic vapor detection

NASA Technical Reports Server (NTRS)

Mottola, Horacio A.

1995-01-01

This work was motivated by the recommendations of the American Conference of Governmental Industrial Hygienists (ACGIH) that threshold limits for hydrazine, H2N-NH2 in air be lowered from 100 to 10 parts-per-billion (ppb) concentration levels. Hydrazine is one of the high-energy propellants used in large volumes in Space Shuttle, Titan, payloads, and other aerospace operations. Since analytical methods presently available for hydrazine detection and/or determination do not satisfy such low levels of detection, the ultimate goal of this research is the development and characterization of a portable and compact chemical sensor ideally capable to detect (in real time) 1 ppb of hydrazine, continuously and reversibly. The laboratory prototype developed as part of this project is comprised of: (1) a reactor part in which H2N-NH2 reacts, generating chemiluminescence emission, with tris(2,2'-bipyridine)ruthenium(III), which is immobilized on an ion-exchange polymeric materials of a perfluorinated hydrocarbon containing sulfonate groups as exchange centers (Nafion); (2) an electrochemical three-electrode cell posed at a potential at which the immobilized ruthenium complex could be reoxidized to the 3-oxidation state (as to provide reversible and continuous detection); and (3) a low power consumption photomultiplier tube to collect and quantitatively integrate the emitted photons with the help of auxiliary electronics and readout device.

Normal values of offline exhaled and nasal nitric oxide in healthy children and teens using chemiluminescence.

PubMed

Menou, A; Babeanu, D; Paruit, H N; Ordureau, A; Guillard, S; Chambellan, A

2017-08-21

Nitric oxide (NO) can be used to detect respiratory or ciliary diseases. Fractional exhaled nitric oxide (FeNO) measurement can reflect ongoing eosinophilic airway inflammation and has a diagnostic utility as a test for asthma screening and follow-up while nasal nitric oxide (nNO) is a valuable screening tool for the diagnosis of primary ciliary dyskinesia. The possibility of collecting airway gas samples in an offline manner offers the advantage to extend these measures and improve the screening and management of these diseases, but normal values from healthy children and teens remain sparse. Samples were consecutively collected using the offline method for eNO and nNO chemiluminescence measurement in 88 and 31 healthy children and teens, respectively. Offline eNO measurement was also performed in 30 consecutive children with naïve asthma and/or respiratory allergy. The normal offline eNO value was determined by the following regression equation -8.206 + 0.176 × height. The upper limit of the norm for the offline eNO value was 27.4 parts per billion (ppb). A separate analysis was performed in children, pre-teens and teens, for which offline eNO was 13.6 ± 4.7 ppb, 16.3 ± 13.7 ppb and 20.0 ± 7.2 ppb, respectively. The optimal cut-off value of the offline eNO to predict asthma or respiratory allergies was 23.3 ppb, with a sensitivity and specificity of 77% and 91%, respectively. Mean offline nNO was determined at 660 ppb with the lower limit of the norm at 197 ppb. The use of offline eNO and nNO normal values should favour the widespread screening of respiratory diseases in children of school age in their usual environment.

Ethylene Production by Plants in a Closed Environment

NASA Technical Reports Server (NTRS)

Wheeler, R. M.; Peterson, B. V.; Sager, J. C.; Knott, W. M.

1996-01-01

Ethylene production by 20-sq m stands of wheat, soybean, lettuce and potato was monitored throughout growth and development in NASA's Controlled Ecological Life Support System (CELSS) Biomass Production Chamber. Chamber ethylene concentrations rose during periods of rapid growth for all four species, reaching 120 parts per billion (ppb) for wheat, 60 ppb for soybean, and 40 to 50 ppb for lettuce and potato. Following this, ethylene concentrations declined during seed fill and maturation (wheat and soybean), or remained relatively constant (potato). Lettuce plants were harvested during rapid growth and peak ethylene production. The highest ethylene production rates (unadjusted for chamber leakage) ranged from 0.04 to 0.06 ml/sq m/day during rapid growth of lettuce and wheat stands, or approximately 0.8 to 1.1 ml/g fresh weight/h. Results suggest that ethylene production by plants is a normal event coupled to periods of rapid metabolic activity, and that ethylene removal or control measures should be considered for growing crops in a tightly closed CELSS.

Sensitivity of Texas strains of Ceratocystis fagacearum to triazole fungicides

Treesearch

A. Dan Wilson; L.B. Forse

1997-01-01

Ten geographically diverse Texas strains of the oak wilt fungus Ceratocystis fagacearum were tested in vitro for their sensitivity to five triazole fungicides based on accumulated linear growth, linear growth rates, and dry weight accumulation in response to fungicide concentrations of 0.1 to 600 parts per billion (ppb). None of the triazoles inhibited growth at 0.1...

Physiological effects of positive pressure breathing with pure oxygen and a low oxygen gas mixture.

PubMed

Liu, Xiaopeng; Xiao, Huajun; Shi, Weiru; Wen, Dongqing; Yu, Lihua; Chen, Jianzhang

2015-01-01

Positive pressure breathing (PPB) can cause circulatory dysfunction due to peripheral pooling of blood. This study explored a better way at ground level to simulate pure oxygen PPB at 59,055 ft (18,000 m) by comparing the physiological changes during PPB with pure oxygen and low oxygen at ground level. Six subjects were exposed to 3 min of 69-mmHg PPB and 3 min of 59-mmHg PPB with pure oxygen and low oxygen while wearing the thoracic counterpressure jerkin inflated to 1× breathing pressure and G-suit inflated to 3 and 4× breathing pressure. Stroke volume (SV), cardiac output (CO), heart rate (HR), and peripheral oxygen saturation (Spo2) were measured. Subjects completed a simulating flying task (SFT) during 3-min PPB and scores were recorded. HR and SV responses differed significantly between breathing pure oxygen and low oxygen. CO response was not significantly different for pure oxygen and low oxygen, the two levels of PPB, and the two levels of G-suit pressure. Spo2 declined as a linear function of time during low-oxygen PPB and there was a significant difference in Spo2 response for the two levels of PPB. The average score of SFT during pure oxygen PPB was 3970.5 ± 1050.4, which was significantly higher than 2708.0 ± 702.7 with low oxygen PPB. Hypoxia and PPB have a synergistic negative effect on both the cardiovascular system and SFT performance. PPB with low oxygen was more appropriate at ground level to investigate physiological responses during PPB and evaluate the protective performance of garments. Liu X, Xiao H, Shi W, Wen D, Yu L, Chen J. Physiological effects of positive pressure breathing with pure oxygen and a low oxygen gas mixture.

Engineering-scale experiments of solar photocatalytic oxidation of trichloroethylene

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pacheco, J.; Prairie, M.; Evans, L.

1990-01-01

A photocatalytic process is being developed to destroy organic contaminants in water. Tests with a common water pollutant, trichlorethylene (TCE), were conducted at the Solar Thermal Test Facility at Sandia with trough systems. Tests at this scale provide verification of laboratory studies and allow examination of design and operation issues that only arise in experiments on a realistic scale. The catalyst, titanium dioxide (TiO{sub 2}), is a harmless material found in paint, cosmetics and even toothpaste. We examined the effect of initial contaminant concentration and the effect of hydrogen peroxide on the photocatalytic decomposition of trichlorethylene (TCE). An aqueous solutionmore » of 5000 parts per billion (ppB) TCE with 0.1 weight {percent} suspended titanium dioxide catalyst required approximately 4.2 minutes of exposure to destroy the TCE to a detection limit of 5 ppB. For a 300 ppB TCE solution, the time required was only 2.5 minutes to reach the same level of destruction. Adding 250 parts per million (ppM) of hydrogen peroxide reduced the time required by about 1 minute. A two parameter Langmuir Hinshelwood model was able to describe the data. A simple flow apparatus was built to test four fixed catalyst supports and to measure their pressure drop and assess their ability to withstand flow conditions typical of a full-sized system. In this paper, we summarize the engineering-scale testing and results. 16 refs., 5 figs.« less

Design, fabrication, and optimization of photo acoustic gas sensor for the trace level detection of NO2 in the atmosphere.

PubMed

Gondal, Mohammed A; Dastageer, Mohamed A

2010-09-01

Photoacoustic (PA) gas sensor for the detection of hazardous NO(2) with detection limit as low as few part per billion by volume (ppbV) has been designed and tested with pulsed UV laser. Some design optimization factors such as the optimum cell geometry, buffer gas etc has been proposed. It was found that a cylindrical cell with many acoustic filters considerably dampens the noise level and also argon as a buffer gas improves the photoacoustic signal level and this combination substantially improved the signal to noise ratio and the limit of detection. Ambiguous decline of photo acoustic signal at higher NO(2) concentration due to the adsorption of NO(2) on the walls of the photoacoustic cells and the dependence of this effect on the buffer gases are also discussed. The PA signal dependence on incident laser energy for three cells was also investigated.

Environmental Implications of Excessive Selenium: A Review

Treesearch

A. Dennis Lemly

1997-01-01

Selenium is a trace element that is normally present in surface waters at concentrations of about 0.1 - 0.3 parts-per-billion; Lemly, 1985a. In slightly greater amounts, i. e., l-5 ppb, it can bioaccumulate in aquatic food chains and become a concentrated dietary source of selenium that is highly toxic to fish and wildlife (Lemly and Smith, 1987; Lemly, 1993a). Dietary...

Determination of Picloram in Soil and Water by Reversed-Phase Liquid Chromatography

Treesearch

M.J.M. Wells; J.L. Michael; D.G. Neary

1984-01-01

A reversed-phase liquid chromatographic method is presneted for the determination of picloram in the parts per billion (ppb) range in soil, soil solution, and stream samples. Quanitification is effected by UV absorpation at 254 nm. Derivatization is not necessary. The method permits 92% ± 7.1 recovery from water samples and 61.8% ± 11.1 recovery from soil samples....

Intercomparison of infrared cavity leak-out spectroscopy and gas chromatography-flame ionization for trace analysis of ethane.

PubMed

Thelen, Sven; Miekisch, Wolfram; Halmer, Daniel; Schubert, Jochen; Hering, Peter; Mürtz, Manfred

2008-04-15

Comparison of two different methods for the measurement of ethane at the parts-per-billion (ppb) level is reported. We used cavity leak-out spectroscopy (CALOS) in the 3 microm wavelength region and gas chromatography-flame ionization detection (GC-FID) for the analysis of various gas samples containing ethane fractions in synthetic air. Intraday and interday reproducibilities were studied. Intercomparing the results of two series involving seven samples with ethane mixing ratios ranging from 0.5 to 100 ppb, we found a reasonable agreement between both methods. The scatter plot of GC-FID data versus CALOS data yields a linear regression slope of 1.07 +/- 0.03. Furthermore, some of the ethane mixtures were checked over the course of 1 year, which proved the long-term stability of the ethane mixing ratio. We conclude that CALOS shows equivalent ethane analysis precision compared to GC-FID, with the significant advantage of a much higher time resolution (<1 s) since there is no requirement for sample preconcentration. This opens new analytical possibilities, e.g., for real-time monitoring of ethane traces in exhaled human breath.

Facility monitoring of chemical warfare agent simulants in air using an automated, field-deployable, miniature mass spectrometer.

PubMed

Smith, Jonell N; Noll, Robert J; Cooks, R Graham

2011-05-30

Vapors of four chemical warfare agent (CWA) stimulants, 2-chloroethyl ethyl sulfide (CEES), diethyl malonate (DEM), dimethyl methylphosphonate (DMMP), and methyl salicylate (MeS), were detected, identified, and quantitated using a fully automated, field-deployable, miniature mass spectrometer. Samples were ionized using a glow discharge electron ionization (GDEI) source, and ions were mass analyzed with a cylindrical ion trap (CIT) mass analyzer. A dual-tube thermal desorption system was used to trap compounds on 50:50 Tenax TA/Carboxen 569 sorbent before their thermal release. The sample concentrations ranged from low parts per billion [ppb] to two parts per million [ppm]. Limits of detection (LODs) ranged from 0.26 to 5.0 ppb. Receiver operating characteristic (ROC) curves are presented for each analyte. A sample of CEES at low ppb concentration was combined separately with two interferents, bleach (saturated vapor) and diesel fuel exhaust (1%), as a way to explore the capability of detecting the simulant in an environmental matrix. Also investigated was a mixture of the four CWA simulants (at concentrations in air ranging from 270 to 380 ppb). Tandem mass (MS/MS) spectral data were used to identify and quantify the individual components. Copyright © 2011 John Wiley & Sons, Ltd.

Baseline ambient gaseous ammonia concentrations in the Four Corners area and eastern Oklahoma, USA.

PubMed

Sather, Mark E; Mathew, Johnson; Nguyen, Nghia; Lay, John; Golod, George; Vet, Robert; Cotie, Joseph; Hertel, Terry; Aaboe, Erik; Callison, Ryan; Adam, Jacque; Keese, Danielle; Freise, Jeremy; Hathcoat, April; Sakizzie, Brenda; King, Michael; Lee, Chris; Oliva, Sylvia; San Miguel, George; Crow, Leon; Geasland, Frank

2008-11-01

Ambient ammonia monitoring using Ogawa passive samplers was conducted in the Four Corners area and eastern Oklahoma, USA during 2007. The resulting data will be useful in the multipollutant management of ozone, nitrogen oxides, and visibility (atmospheric regional haze) in the Four Corners area, an area with growing oil/gas production and increasing coal-based power plant construction. The passive monitoring data also add new ambient ammonia concentration information for the U.S. and will be useful to scientists involved in present and future visibility modeling exercises. Three week integrated passive ammonia samples were taken at five sites in the Four Corners area and two sites in eastern Oklahoma from December, 2006 through December, 2007 (January, 2008 for two sites). Results show significantly higher regional background ammonia concentrations in eastern Oklahoma (1.8 parts per billion (ppb) arithmetic mean) compared to the Four Corners area (0.2 ppb arithmetic mean). Annual mean ammonia concentrations for all Four Corners area sites for the 2007 study ranged from 0.2 ppb to 1.5 ppb. Peak ambient ammonia concentrations occurred in the spring and summer in both areas. The passive samplers deployed at the Stilwell, Oklahoma site compared favorably with other passive samplers and a continuous ammonia monitoring instrument.

The Origin of Amino Acids in Lunar Regolith Samples

NASA Technical Reports Server (NTRS)

Cook, Jamie E.; Callahan, Michael P.; Dworkin, Jason P.; Glavin, Daniel P.; McLain, Hannah L.; Noble, Sarah K.; Gibson, Everett K., Jr.

2016-01-01

We analyzed the amino acid content of seven lunar regolith samples returned by the Apollo 16 and Apollo 17 missions and stored under NASA curation since collection using ultrahigh-performance liquid chromatography with fluorescence detection and time-of-flight mass spectrometry. Consistent with results from initial analyses shortly after collection in the 1970s, we observed amino acids at low concentrations in all of the curated samples, ranging from 0.2 parts-per-billion (ppb) to 42.7 ppb in hot-water extracts and 14.5 ppb to 651.1 ppb in 6M HCl acid-vapor-hydrolyzed, hot-water extracts. Amino acids identified in the Apollo soil extracts include glycine, D- and L-alanine, D- and L-aspartic acid, D- and L-glutamic acid, D- and L-serine, L-threonine, and L-valine, all of which had previously been detected in lunar samples, as well as several compounds not previously identified in lunar regoliths: -aminoisobutyric acid (AIB), D-and L-amino-n-butyric acid (-ABA), DL-amino-n-butyric acid, -amino-n-butyric acid, -alanine, and -amino-n-caproic acid. We observed an excess of the L enantiomer in most of the detected proteinogenic amino acids, but racemic alanine and racemic -ABA were present in some samples.

The Anatomy of High Levels of Wintertime Photochemical Ozone Production in the Uintah Basin, Utah, 2013

NASA Astrophysics Data System (ADS)

Schnell, R. C.; Oltmans, S. J.; Johnson, B.; Petron, G.; Neely, R. R.

2013-12-01

The Uintah Basin, Utah is ~ 5,000 km2 in size with lower elevations of ~1400 m msl ringed by mountains rising to ~3,000 m. Within this basin are 6,000 gas wells that produced 10 billion m3 of natural gas and 4,000 oil wells that produced ~22 million barrels of oil in 2012. In winter, the confined geography in the basin traps effluents from these fossil fuel extraction activities into a shallow layer (a few 100 meters deep) beneath strong temperature inversions, especially when ample snow cover is present throughout the basin. The temperature inversions isolate the basin from upper level winds that allow for stagnant conditions that may last for a week or more before a frontal system may flush the basin out. The highly reflective snow provides for enhanced photolysis rates that in February are comparable to those in June. In 2013 December snowfall in the Uintah Basin persisted until early March with exceptionally elevated ozone production occurring in four distinct, 10-day periods separated by 2-3 days of near background values following frontal induced washouts of the basins. In one well studied ozone event, background ozone levels of 55 ppb in the basin were measured from the surface to the lower troposphere on January 30, 2013. By February 1, ozone concentrations from the surface to the top of the 180 m deep temperature inversion averaged 100 ppb. By February 6 ozone concentrations were 165 ppb throughout the same layer. From aircraft measurements these ozone concentrations were observed to be fairly well mixed throughout the basin although there were some notable hotspots. Clean-out of ozone and ozone precursors in the Uintah Basin was observed to occur within 4 hours or less as basin air was replaced with air coming in from the west coast and mixing to the surface.

Detecting Airborne Mercury by Use of Palladium Chloride

NASA Technical Reports Server (NTRS)

Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Jewell, April; Manatt, Kenneth; Torres, Julia; Soler, Jessica; Taylor, Charles

2009-01-01

Palladium chloride films have been found to be useful as alternatives to the gold films heretofore used to detect airborne elemental mercury at concentrations of the order of parts per billion (ppb). Somewhat more specifically, when suitably prepared palladium chloride films are exposed to parts-per-billion or larger concentrations of airborne mercury, their electrical resistances change by amounts large enough to be easily measurable. Because airborne mercury adversely affects health, it is desirable to be able to detect it with high sensitivity, especially in enclosed environments in which there is a risk of leakage of mercury from lamps or other equipment. The detection of mercury by use of gold films involves the formation of gold/mercury amalgam. Gold films offer adequate sensitivity for detection of airborne mercury and could easily be integrated into an electronic-nose system designed to operate in the temperature range of 23 to 28 C. Unfortunately, in order to regenerate a gold-film mercury sensor, one must heat it to a temperature of 200 C for several minutes in clean flowing air. In preparation for an experiment to demonstrate the present sensor concept, palladium chloride was deposited from an aqueous solution onto sets of gold electrodes and sintered in air to form a film. Then while using the gold electrodes to measure the electrical resistance of the films, the films were exposed, at a temperature of 25 C, to humidified air containing mercury at various concentrations from 0 to 35 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury in room-temperature air at concentrations of at least 2.5 ppb and can readily be regenerated at temperatures <40 C.

Temporal trends (1989–2011) in levels of mercury and other heavy metals in feathers of fledgling great egrets nesting in Barnegat Bay, NJ

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna, E-mail: burger@biology.rutgers.edu

There is an abundance of data for levels of metals from a range of species, but relatively few long-term time series from the same location. In this paper I examine the levels of arsenic, cadmium, chromium, lead, manganese, mercury and selenium in feathers from fledgling great egrets (Ardea alba) collected at nesting colonies in Barnegat Bay, New Jersey from 1989 to 2011. The primary objectives were to test the null hypotheses that (1) There were no temporal differences in metal levels in feathers of fledgling great egrets, and (2) Great egrets nesting in different areas of Barnegat Bay (New Jersey)more » did not differ in metal levels. There were significant yearly variations in levels of all heavy metals in feathers of fledgling great egret, but levels decreased significantly from 1989 to 2011 only for lead (1470 ppb to 54.3 ppb), cadmium (277 ppb to 30.5 ppb), and manganese (only since 1996; 2669 ppb to 329 ppb)). Although mercury levels decreased from 2003–2008 (6430 ppb to 1042 ppb), there was no pattern before 2003, and levels increased after 2008 to 2610 ppb in 2011. Lead, cadmium, chromium, manganese and mercury were higher in feathers from great egrets nesting in the northern part of the bay, and selenium was highest in feathers from mid-bay. The lack of a temporal decline in mercury levels in feathers of great egrets is cause for concern, since the high levels in feathers from some years (means as high as 6430 ppb) are in the range associated with adverse effects (5000 ppb for feathers). -- Highlights: ► Metals were monitored in feathers of great egrets from Barnegat Bay, New Jersey. ► Levels of cadmium and lead decreased significantly from 1989–2011. ► Mercury levels in feathers from great egrets did not decline from 1989–2011. ► Metal levels were generally higher in great egrets and black-crowned night heron feathers than in snowy egrets.« less

Nitrogen dioxide and respiratory illness in children. Part II: Assessment of exposure to nitrogen dioxide.

PubMed

Lambert, W E; Samet, J M; Hunt, W C; Skipper, B J; Schwab, M; Spengler, J D

1993-06-01

Repeated measurements of nitrogen dioxide were obtained from 1988 to 1991 in the homes of 1,205 infants living in Albuquerque, NM. Passive diffusion samplers were used to obtain a series of two-week integrated measurements from the home of each infant for use in a cohort study of the relation of residential exposure to nitrogen dioxide and respiratory illnesses. Information on stove use and time spent inside the residence was collected at two-week and two-month intervals, respectively. During the winter, in the bedrooms of homes with gas cooking stoves, mean nitrogen dioxide concentrations were 21 parts per billion (ppb); mean concentrations in the living room and kitchen were 29 ppb and 34 ppb, respectively. In homes with electric cooking stoves, the mean bedroom concentration was 7 ppb during the winter. Lower indoor concentrations were observed during the summer in homes with both gas and electric stoves. On average, infants spent approximately 12.3 hours per day in their bedrooms, 7.3 hours in the living rooms, 35 minutes in the kitchens, and 3.8 hours out of their homes. (As a condition of participation, none of the infants spent more than 20 hours per week in day care outside of their homes). The mean time infants spent in the kitchen during cooking was approximately nine minutes per day. We tested whether exposures of infants living in homes with gas stoves could be reasonably estimated by measurements in the bedroom in comparison with time-weighted average concentrations based on time-activity data and simultaneous nitrogen dioxide measurements in the kitchen, living room, and bedroom. In 1,937 two-week intervals from 587 infants, 90% of time-weighted exposure (on the three-level classification used in this study) estimates were in agreement with estimates based on bedroom concentrations alone. The agreement of the time-weighted nitrogen dioxide exposure estimates with the bedroom concentrations is attributed to limited amounts of cooking stove use (the mean was 29 minutes per day), small room-to-room differences in nitrogen dioxide concentrations (the mean kitchen-bedroom difference was 12 ppb), and the relatively large proportion of time that infants spent in their bedrooms.

Public health assessment for New Brighton/Arden Hills (A/K/A US Army Twin Cities ammunition plant), New Brighton, Ramsey County, Minnesota, Region 5. Cerclis No. MN213820908. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1994-05-24

The New Brighton/Arden Hills National Priorities List (NPL) Site in Ramsey County, Minnesota, includes the 4-square-mile Twin Cities Army Ammunition Plant (TCAAP) and portions of seven nearby communities: New Brighton, St. Anthony, Arden Hills, Shoreview, Mounds View, Columbia Heights, and Minneapolis. In June 1981, the Minnesota Pollution Control Agency (MPCA) and the Minnesota Department of Health (MDH) discovered trichloroethylene (TCE) and other volatile organic compounds (VOCs) in municipal, mobile home park, and private well water in the vicinity of TCAAP. Initial analysis of TCAAP water supply wells revealed high concentrations of TCE (720 parts per billion ppb), 1,1,1-trichloroethane (360 ppb),more » 1,1-dichloroethane (130 ppb), and other VOCs. From its review of available data, ATSDR concludes that hazardous waste sites within TCAAP are public health hazards because people were exposed in the past to groundwater contaminants at concentrations that may cause adverse health effects.« less

Trace gases and air mass origin at Kaashidhoo, Indian Ocean

NASA Astrophysics Data System (ADS)

Lobert, Jürgen M.; Harris, Joyce M.

2002-10-01

Carbon monoxide (CO) was measured at the Kaashidhoo Climate Observatory (KCO, Republic of Maldives) between February 1998 and March 2000 to assess the regional pollution of the remote atmosphere in the northern Indian Ocean. CO showed a distinct annual cycle with maximum daily mixing ratios of around 240 parts per billion (ppb), a seasonal difference of about 200 ppb, and high variability during the dry seasons. Detailed air mass trajectory analysis for 1998, 1999, and 2000 was used to identify source regions and to associate them with various levels of pollution encountered at KCO. We conclude that most significant changes in local pollution throughout the year are caused by changes in air masses. Air at KCO generally originated from three main regions with decreasing pollution: India and southeast Asia, the Arabian Sea, and the Southern Hemisphere. We show that isentropic air mass trajectories can be used to predict CO pollution levels at KCO to a certain extent and vice versa. Nitrous oxide, CFC-11, CFC-12, CCI4, and SF6 were measured during the Indian Ocean Experiment (February to March 1999) to support pollution analysis and to confirm that India is the main source for heavy pollution measured at KCO. Correlations between CO and other gases and aerosol properties measured at the surface illustrate that CO may also be used as a proxy for aerosol loading and general pollution at the surface.

Use of electrochemical sensors for measurement of air pollution: correcting interference response and validating measurements

NASA Astrophysics Data System (ADS)

Cross, Eben S.; Williams, Leah R.; Lewis, David K.; Magoon, Gregory R.; Onasch, Timothy B.; Kaminsky, Michael L.; Worsnop, Douglas R.; Jayne, John T.

2017-09-01

The environments in which we live, work, and play are subject to enormous variability in air pollutant concentrations. To adequately characterize air quality (AQ), measurements must be fast (real time), scalable, and reliable (with known accuracy, precision, and stability over time). Lower-cost air-quality-sensor technologies offer new opportunities for fast and distributed measurements, but a persistent characterization gap remains when it comes to evaluating sensor performance under realistic environmental sampling conditions. This limits our ability to inform the public about pollution sources and inspire policy makers to address environmental justice issues related to air quality. In this paper, initial results obtained with a recently developed lower-cost air-quality-sensor system are reported. In this project, data were acquired with the ARISense integrated sensor package over a 4.5-month time interval during which the sensor system was co-located with a state-operated (Massachusetts, USA) air quality monitoring station equipped with reference instrumentation measuring the same pollutant species. This paper focuses on validating electrochemical (EC) sensor measurements of CO, NO, NO2, and O3 at an urban neighborhood site with pollutant concentration ranges (parts per billion by volume, ppb; 5 min averages, ±1σ): [CO] = 231 ± 116 ppb (spanning 84-1706 ppb), [NO] = 6.1 ± 11.5 ppb (spanning 0-209 ppb), [NO2] = 11.7 ± 8.3 ppb (spanning 0-71 ppb), and [O3] = 23.2 ± 12.5 ppb (spanning 0-99 ppb). Through the use of high-dimensional model representation (HDMR), we show that interference effects derived from the variable ambient gas concentration mix and changing environmental conditions over three seasons (sensor flow-cell temperature = 23.4 ± 8.5 °C, spanning 4.1 to 45.2 °C; and relative humidity = 50.1 ± 15.3 %, spanning 9.8-79.9 %) can be effectively modeled for the Alphasense CO-B4, NO-B4, NO2-B43F, and Ox-B421 sensors, yielding (5 min average) root mean square errors (RMSE) of 39.2, 4.52, 4.56, and 9.71 ppb, respectively. Our results substantiate the potential for distributed air pollution measurements that could be enabled with these sensors.

Tracking Se Assimilation and Speciation through the Rice Plant – Nutrient Competition, Toxicity and Distribution

PubMed Central

Eiche, Elisabeth; Riemann, Michael; Nick, Peter; Winkel, Lenny H. E.; Göttlicher, Jörg; Steininger, Ralph; Brendel, Rita; von Brasch, Matthias; Konrad, Gabriele; Neumann, Thomas

2016-01-01

Up to 1 billion people are affected by low intakes of the essential nutrient selenium (Se) due to low concentrations in crops. Biofortification of this micronutrient in plants is an attractive way of increasing dietary Se levels. We investigated a promising method of Se biofortification of rice seedlings, as rice is the primary staple for 3 billion people, but naturally contains low Se concentrations. We studied hydroponic Se uptake for 0–2500 ppb Se, potential phyto-toxicological effects of Se and the speciation of Se along the shoots and roots as a function of added Se species, concentrations and other nutrients supplied. We found that rice germinating directly in a Se environment increased plant-Se by factor 2–16, but that nutrient supplementation is required to prevent phyto-toxicity. XANES data showed that selenite uptake mainly resulted in the accumulation of organic Se in roots, but that selenate uptake resulted in accumulation of selenate in the higher part of the shoot, which is an essential requirement for Se to be transported to the grain. The amount of organic Se in the plant was positively correlated with applied Se concentration. Our results indicate that biofortification of seedlings with selenate is a successful method to increase Se levels in rice. PMID:27116220

Honeybees Produce Millimolar Concentrations of Non-Neuronal Acetylcholine for Breeding: Possible Adverse Effects of Neonicotinoids.

PubMed

Wessler, Ignaz; Gärtner, Hedwig-Annabel; Michel-Schmidt, Rosmarie; Brochhausen, Christoph; Schmitz, Luise; Anspach, Laura; Grünewald, Bernd; Kirkpatrick, Charles James

2016-01-01

The worldwide use of neonicotinoid pesticides has caused concern on account of their involvement in the decline of bee populations, which are key pollinators in most ecosystems. Here we describe a role of non-neuronal acetylcholine (ACh) for breeding of Apis mellifera carnica and a so far unknown effect of neonicotinoids on non-target insects. Royal jelly or larval food are produced by the hypopharyngeal gland of nursing bees and contain unusually high ACh concentrations (4-8 mM). ACh is extremely well conserved in royal jelly or brood food because of the acidic pH of 4.0. This condition protects ACh from degradation thus ensuring delivery of intact ACh to larvae. Raising the pH to ≥5.5 and applying cholinesterase reduced the content of ACh substantially (by 75-90%) in larval food. When this manipulated brood was tested in artificial larval breeding experiments, the survival rate was higher with food supplemented by 100% with ACh (6 mM) than with food not supplemented with ACh. ACh release from the hypopharyngeal gland and its content in brood food declined by 80%, when honeybee colonies were exposed for 4 weeks to high concentrations of the neonicotinoids clothianidin (100 parts per billion [ppb]) or thiacloprid (8,800 ppb). Under these conditions the secretory cells of the gland were markedly damaged and brood development was severely compromised. Even field-relevant low concentrations of thiacloprid (200 ppb) or clothianidin (1 and 10 ppb) reduced ACh level in the brood food and showed initial adverse effects on brood development. Our findings indicate a hitherto unknown target of neonicotinoids to induce adverse effects on non-neuronal ACh which should be considered when re-assessing the environmental risks of these compounds. To our knowledge this is a new biological mechanism, and we suggest that, in addition to their well documented neurotoxic effects, neonicotinoids may contribute to honeybee colony losses consecutive to a reduction of the ACh content in the brood food.

Environmental and occupational exposure to benzene in Thailand.

PubMed

Navasumrit, Panida; Chanvaivit, Sirirat; Intarasunanont, Pornpat; Arayasiri, Manaswee; Lauhareungpanya, Narumon; Parnlob, Varaporn; Settachan, Daam; Ruchirawat, Mathuros

2005-05-30

Exposure to benzene in air is a concern in Thailand, particularly since it was observed that the incidence of blood-related cancers, such as leukemia and lymphoma, has increased in the past few decades. In Bangkok, the mean atmospheric levels of benzene on main roads and in schools were 33.71 and 8.25 ppb, respectively, while in gasoline service stations and petrochemical factories the mean ambient levels were 64.78 and 66.24 ppb, respectively. Cloth vendors (22.61 ppb) and grilled-meat vendors (28.19 ppb) working on the roadsides were exposed to significantly higher levels of benzene than the control group (12.95 ppb; p<0.05). Bangkok school children (5.50 ppb) were exposed to significantly higher levels of benzene than provincial school children (2.54 ppb; p<0.01). Factory workers (73.55 ppb) and gasoline service attendants (121.67 ppb) were exposed to significantly higher levels of benzene than control workers (4.77 ppb; p<0.001). In accordance with the increased benzene exposures, levels of urinary trans,trans-muconic acid (MA) were significantly increased in all benzene-exposed groups. In school children, the levels of MA were relatively high, taking into account the much lower level of exposure. Blood benzene levels were also significantly increased in Bangkok school children (77.97 ppt; p<0.01), gasoline service attendants (641.84 ppt; p<0.05) and factory workers (572.61 ppt; p<0.001), when compared with the respective controls. DNA damage, determined as DNA strand breaks, was found to be elevated in gasoline service attendants, petrochemical factory workers, and Bangkok school children (p<0.001). The cytogenetic challenge assay, which measures DNA repair capacity, showed varying levels of significant increases in the numbers of dicentrics and deletions in gasoline service attendants, petrochemical factory workers and Bangkok school children, indicating a decrease in DNA repair capacity in these subjects.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hichwa, B.P.; Pun, D.D.; Wang, D.

A multielemental analysis to determine the trace metal content of generic and name-brand aspirins and name-brand lipsticks was done via proton induced x-ray (PIXE) measurements. The Hope College PIXE system is described as well as the target preparation methods. The trace metal content of twelve brands of aspirin and aspirin substitutes and fourteen brands of lipstick are reported. Detection limits for most elements are in the range of 100 parts per billion (ppb) to 10 parts per million (ppm).

Benzene levels in ambient air and breath of smokers and nonsmokers in urban and pristine environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wester, R.C.; Maibach, H.I.; Gruenke, L.D.

Benzene levels in human breath and in ambient air were compared in the urban area of San Francisco (SF) and in a more remote coastal pristine setting of Stinson Beach, Calif. (SB). Benzene analysis was done by gas chromatography-mass spectroscopy (GC-MS). Ambient benzene levels were sevenfold higher in SF (2.6 +/- 1.3 ppb, n = 25) than SB (0.38 +/- 0.39 ppb, n = 21). In SF, benzene in smokers' breath (6.8 +/- 3.0 ppb) was greater than in nonsmokers' breath (2.5 +/- 0.8 ppb) and smokers' ambient air (3.3 +/- 0.8 ppb). In SB the same pattern was observed:more » benzene in smokers' breath was higher than in nonsmokers' breath and ambient air. Benzene in SF nonsmokers' breath was greater than in SB nonsmokers' breath. Marijuana-only smokers had benzene breath levels between those of smokers and nonsmokers. There was little correlation between benzene in breath and number of cigarettes smoked, or with other benzene exposures such as diet. Of special interest was the finding that benzene in breath of SF nonsmokers (2.5 +/- 0.8 ppb) was greater than that in nonsmokers ambient air (1.4 +/- 0.1 ppb). The same was true in SB, where benzene in nonsmokers breath was greater than ambient air (1.8 +/- 0.2 ppb versus 1.0 +/- 0.1 ppb on d 1 and 1.3 +/- 0.3 ppb versus 0.23 +/- 0.18 ppb on d 2). This suggests an additional source of benzene other than outdoor ambient air.« less

Use of laboratory spectrometry to predict the detection of phytoplankton luminescence by an airborne Fraunhofer line discriminator

USGS Publications Warehouse

Watson, Robert D.; Theisen, Arnold F.; Prezelin, Barbara B.

1981-01-01

Laboratory measurements of the excitation spectra of 13 species of phytoplankton (six diatoms, five dinoflagellates and two chrysophytes) were obtained with the emission wavelength held constant at 656.3 nm and the excitation wavelength scanned from 320 to 640 nm. Integrated excitation intensities were normalized to a standard concentration of rhodamine wt dye and the resulting luminescence compared to the minimum detectable FLD level of 0.12 parts per billion (p.p.b.) rhodamine wt. Results demonstrated that all 13 species would be detectable with an FLD at concentrations of 10.0 and 5.0 μg/1 of chlorophyll a and that only one would not be detectable at a chlorophyll a concentration of 1.0 μg/1.

The relation between respiratory illness in primary schoolchildren and the use of gas for cooking--II. Factors affecting nitrogen dioxide levels in the home.

PubMed

Goldstein, B D; Melia, R J; Chinn, S; Florey, C V; Clark, D; John, H H

1979-12-01

The study was designed to determine whether there was an association between indoor levels of nitrogen dioxide (NO2) and respiratory illness and lung function in schoolchildren. NO2 was measured for one week in the winter outside and inside the homes of children aged 6-7 years living and attending primary schools in a defined 4 square km area in Middlesbrough, Cleveland, UK. Outdoor levels of NO2 measured at 75 points within the area ranged from 14-24 ppb weekly average. Measurements were also made in 428 kitchens with gas cookers, range 5-317 ppb, mean 112.2 ppb, and in 87 kitchens with electric cookers, range 6-188 ppb, mean 18.0 ppb. In a random subsample of homes the range of NO2 levels in 107 children's bedrooms in homes where gas was used for cooking was 4-169 ppb, mean 30.5 ppb, in 18 bedrooms in electric cooking homes the range was 3-37 ppb, mean 13.9 ppb. NO2 levels in the gas cooking kitchens were positively related to the presence of pilot lights, use of gas fires for main heating, number of regular smokers, and the number of people in the home. Information from 29 homes with the highest kitchen NO2 levels paired with 29 low NO2 gas cooking homes showed that the daily number of meals eaten and the frequency with which the cooker was used for heating and drying clothes were significantly greater in the high NO2 homes.

Development of narrow-band fluorescence index for the detection of aflatoxin contaminated corn

NASA Astrophysics Data System (ADS)

Yao, Haibo; Hruska, Zuzana; Kincaid, Russell; Ononye, Ambrose; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

2011-06-01

Aflatoxin is produced by the fungus Aspergillus flavus when the fungus invades developing corn kernels. Because of its potent toxicity, the levels of aflatoxin are regulated by the Food and Drug Administration (FDA) in the US, allowing 20 ppb (parts per billion) limits in food, and feed intended for interstate commerce. Currently, aflatoxin detection and quantification methods are based on analytical tests. These tests require the destruction of samples, can be costly and time consuming, and often rely on less than desirable sampling techniques. Thus, the ability to detect aflatoxin in a rapid, non-invasive way is crucial to the corn industry in particular. This paper described how narrow-band fluorescence indices were developed for aflatoxin contamination detection based on single corn kernel samples. The indices were based on two bands extracted from full wavelength fluorescence hyperspectral imagery. The two band results were later applied to two large sample experiments with 25 g and 1 kg of corn per sample. The detection accuracies were 85% and 95% when 100 ppb threshold was used. Since the data acquisition period is significantly lower for several image bands than for full wavelength hyperspectral data, this study would be helpful in the development of real-time detection instrumentation for the corn industry.

A new sensor for the assessment of personal exposure to volatile organic compounds

NASA Astrophysics Data System (ADS)

Chen, Cheng; Driggs Campbell, Katherine; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica S.

2012-07-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real-time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts-per-billion (ppb), with a detection range of 4 ppb-1000 ppm (parts-per-million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology.

A New Sensor for the Assessment of Personal Exposure to Volatile Organic Compounds

PubMed Central

Chen, Cheng; Campbell, Katherine Driggs; Negi, Indira; Iglesias, Rodrigo A.; Owens, Patrick; Tao, Nongjian; Tsow, Francis; Forzani, Erica

2012-01-01

To improve our understanding of indoor and outdoor personal exposures to common environmental toxicants released into the environment, new technologies that can monitor and quantify the toxicants anytime anywhere are needed. This paper presents a wearable sensor to provide such capabilities. The sensor can communicate with a common smart phone and provides accurate measurement of volatile organic compound concentration at a personal level in real time, providing environmental toxicants data every three minutes. The sensor has high specificity and sensitivity to aromatic, alkyl, and chlorinated hydrocarbons with a resolution as low as 4 parts per billion (ppb), with a detection range of 4 ppb to 1000 ppm (parts per million). The sensor's performance was validated using Gas Chromatography and Selected Ion Flow Tube - Mass Spectrometry reference methods in a variety of environments and activities with overall accuracy higher than 81% (r2 > 0.9). Field tests examined personal exposure in various scenarios including: indoor and outdoor environments, traffic exposure in different cities which vary from 0 to 50 ppmC (part-per-million carbon from hydrocarbons), and pollutants near the 2010 Deepwater Horizon's oil spill. These field tests not only validated the performance but also demonstrated unprecedented high temporal and spatial toxicant information provided by the new technology. PMID:22736952

Industrial-hygiene survey report, Wabash Magnetic Company, Huntington, Indiana, May 24-26, 1988. [4,4'-methylenedianiline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boeniger, M.F.

1989-01-01

A walk-through survey was made at Wabash Magnetic Company, located in Huntington, Indiana for the purpose of determining the extent of worker exposure to 4,4'-methylenedianiline (MDA) in a batch type mixing operation and user of B-stage resins. At this site the chemical was used as a hardening agent to produce the resins used to make transfer-molded parts. Air, wipe, bulk, and urine samples were taken to determine exposure levels. In both the formulating and molding departments, evidence was found for the possible inhalation of and dermal contact with MDA. Air concentrations were detectable, but were below the permissible exposure levelmore » of 10 parts per billion (ppb) proposed by OSHA. Of seven workers monitored by urinalysis, two were excreting detectable amounts of MDA with the higher concentration being 16 ppb. The author recommends a combination of modified work practices and alternative personal protection to reduce exposures. A vacuum installed with a HEPA filter should be used in the dry cleanup processes in the mixing and formulating departments and workers should wear a glove more resistant to permeation than the cotton ones now in use at the site. Gloves made of polyvinylchloride or natural latex are suggested.« less

Use of radioimmunoassay as a screen for antibiotics in confined animal feeding operations and confirmation by liquid chromatography/mass spectrometry

USGS Publications Warehouse

Meyer, M.T.; Bumgarner, J.E.; Varns, J.L.; Daughtridge, J.V.; Thurman, E.M.; Hostetler, K.A.

2000-01-01

Approximately one-half of the 50 000000 lb of antibiotics produced in the USA are used in agriculture. Because of the intensive use of antibiotics in the management of confined livestock operations, the potential exists for the transport of these compounds and their metabolites into our nation's water resources. A commercially available radioimmunoassay method, developed as a screen for tetracycline antibiotics in serum, urine, milk, and tissue, was adapted to analyze water samples at a detection level of approximately 1.0 ppb and a semiquantitative analytical range of 1-20 ppb. Liquid waste samples were obtained from 13 hog lagoons in three states and 52 surface- and ground-water samples were obtained primarily from areas associated with intensive swine and poultry production in seven states. These samples were screened for the tetracycline antibiotics by using the modified radioimmunoassay screening method. The radioimmunoassay tests yielded positive results for tetracycline antibiotics in samples from all 13 of the hog lagoons. Dilutions of 10-100-fold of the hog lagoon samples indicated that tetracycline antibiotic concentrations ranged from approximately 5 to several hundred parts per billion in liquid hog lagoon waste. Of the 52 surface- and ground-water samples collected all but two tested negative and these two samples contained tetracycline antibiotic concentrations less than 1 ppb. A new liquid chromatography/mass spectrometry method was used to confirm the radioimmunoassay results in 9 samples and also to identify the tetracycline antibiotics to which the radioimmunoassay test was responding. The new liquid chromatography/mass spectrometry method with online solid-phase extraction and a detection level of 0.5 ??g/l confirmed the presence of chlorotetracycline in the hog lagoon samples and in one of the surface-water samples. The concentrations calculated from the radioimmunoassay were a factor of 1-5 times less than those calculated by the liquid chromatography/mass spectrometry concentrations for chlorotetracycline. Copyright (C) 2000 Elsevier Science B.V.

Assimilation of atmospheric methane products into the MACC-II system: from SCIAMACHY to TANSO and IASI

NASA Astrophysics Data System (ADS)

Massart, S.; Agusti-Panareda, A.; Aben, I.; Butz, A.; Chevallier, F.; Crevosier, C.; Engelen, R.; Frankenberg, C.; Hasekamp, O.

2014-06-01

The Monitoring Atmospheric Composition and Climate Interim Implementation (MACC-II) delayed-mode (DM) system has been producing an atmospheric methane (CH4) analysis 6 months behind real time since June 2009. This analysis used to rely on the assimilation of the CH4 product from the SCanning Imaging Absorption spectroMeter for Atmospheric CHartographY (SCIAMACHY) instrument onboard Envisat. Recently the Laboratoire de Météorologie Dynamique (LMD) CH4 products from the Infrared Atmospheric Sounding Interferometer (IASI) and the SRON Netherlands Institute for Space Research CH4 products from the Thermal And Near-infrared Sensor for carbon Observation (TANSO) were added to the DM system. With the loss of Envisat in April 2012, the DM system now has to rely on the assimilation of methane data from TANSO and IASI. This paper documents the impact of this change in the observing system on the methane tropospheric analysis. It is based on four experiments: one free run and three analyses from respectively the assimilation of SCIAMACHY, TANSO and a combination of TANSO and IASI CH4 products in the MACC-II system. The period between December 2010 and April 2012 is studied. The SCIAMACHY experiment globally underestimates the tropospheric methane by 35 part per billion (ppb) compared to the HIAPER Pole-to-Pole Observations (HIPPO) data and by 28 ppb compared the Total Carbon Column Observing Network (TCCON) data, while the free run presents an underestimation of 5 ppb and 1 ppb against the same HIPPO and TCCON data, respectively. The assimilated TANSO product changed in October 2011 from version v.1 to version v.2.0. The analysis of version v.1 globally underestimates the tropospheric methane by 18 ppb compared to the HIPPO data and by 15 ppb compared to the TCCON data. In contrast, the analysis of version v.2.0 globally overestimates the column by 3 ppb. When the high density IASI data are added in the tropical region between 30° N and 30° S, their impact is mainly positive but more pronounced and effective when combined with version v.2.0 of the TANSO products. The resulting analysis globally underestimates the column-averaged dry-air mole fractions of methane (xCH4) just under 1 ppb on average compared to the TCCON data, whereas in the tropics it overestimates xCH4 by about 3 ppb. The random error is estimated to be less than 7 ppb when compared to TCCON data.

[Effect of chewing gum on halitosis].

PubMed

De Luca-Monasterios, Fiorella; Chimenos-Küstner, Eduardo; López-López, José

2014-07-22

This study aims to estimate the prevalence of oral halitosis in a young population and show the effect of chewing gum on their breath. Prospective, descriptive correlational cross section study. We selected a convenience sample of 121 young individuals and 98 completed the study. It was carried out at the University Dental Hospital-University of Barcelona. The protocol consisted of: questionnaire, oral clinical evaluation, organoleptic tests (OT) and measurement of volatile sulfur compounds (VSC) with sulphide monitoring before and after chewing gum during 15 min, with 2 calibrated investigators. A percentage of 87.8 had adequate oral hygiene, 17.3% reported bad breath and 29.6% had xerostomia. Forty-four subjects had a OT grade ≥2; the agreement of examiners was 75%. The VSC in 53 individuals were ≤100 parts per billion (ppb) and in 45 subjects, it was>100 ppb. A post-reduction of VSC of 17.34% was obtained with a mean decrease of 1.8-9.0 ppb (P=.003). The prevalence of halitosis was 36.7%. The use of chewing gum as an adjunct in cases of halitosis decreases the VSC, improving the perception of others and the patient. Copyright © 2013 Elsevier España, S.L. All rights reserved.

Determination of 2,4-dichlorophenoxyacetic acid (2,4-D) in human urine with mass selective detection.

PubMed

Hughes, D L; Ritter, D J; Wilson, R D

2001-11-01

Method development and validation studies have been completed on an assay that will allow the determination of 2,4-dichlorophenoxyacetic acid (2,4-D) in human urine. The accurate determination of 2,4-D in urine is an important factor in monitoring worker and population exposure. These studies successfully validated a method for the detection of 2,4-D in urine at a limit of quantitation (LOQ) of 5.00 ppb (parts per billion) using gas chromatography with mass selective detection (GC/MSD). The first study involved the determination of 2,4-D in control human urine and urine samples fortified with 2,4-D. Due to chromatographic interference, a second study was conducted using 14C-2,4-D to verify the recoverability of 2,4-D from human urine at low levels using the GC/MSD method. The second study supports the results of the original data. The 2,4-D was extracted from human urine using a procedure involving hydrolysis using potassium hydroxide, followed by a liquid-liquid extraction into methylene chloride. The extracted samples were derivatized with diazomethane. The methylated fraction was analyzed by GC/MSD. Quantitation was made by comparison to methylated reference standards of 2,4-D. Aliquots fortified at 5-, 50-, and 500-ppb levels were analyzed. The overall mean recovery for all fortified samples was 90.3% with a relative standard deviation of 14.31%.

Assessment of metals in down feathers of female common eiders and their eggs from the Aleutians: arsenic, cadmium, chromium, lead, manganese, mercury, and selenium

PubMed Central

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Snigaroff, Daniel; Snigaroff, Ronald; Stamm, Timothy; Volz, Conrad

2014-01-01

Concentrations of arsenic, cadmium, chromium, lead, manganese, mercury and selenium were examined in the down feathers and eggs of female common eiders (Somateria mollissima) from Amchitka and Kiska Islands in the Aleutian Chain of Alaska to determine whether there were (1) differences between levels in feathers and eggs, (2) differences between the two islands, (3) positive correlations between metal levels in females and their eggs, and (4) whether there was more variation within or among clutches. Mean levels in eggs (dry weight) were as follows: arsenic (769 ppb, ng/g), cadmium (1.49 ppb), chromium (414 ppb), lead (306 ppb), manganese (1,470 ppb), mercury (431 ppb) and selenium (1,730 ppb). Levels of arsenic were higher in eggs, while chromium, lead, manganese, and mercury were higher in feathers; there were no differences for selenium. There were no significant interisland differences in female feather levels, except for manganese (eider feathers from Amchitka were four times higher than feathers from Kiska). Levels of manganese in eggs were also higher from Amchitka than Kiska, and eider eggs from Kiska had significantly higher levels of arsenic, but lower levels of selenium. There were no significant correlations between the levels of any metals in down feathers of females and in their eggs. The levels of mercury in eggs were below ecological benchmark levels, and were below human health risk levels. However, Aleuts can seasonally consume several meals of bird eggs a week, suggesting cause for concern for sensitive (pregnant) women. PMID:17934788

Aflatoxin contamination in corn sold for wildlife feed in texas.

PubMed

Dunham, Nicholas R; Peper, Steven T; Downing, Carson D; Kendall, Ronald J

2017-05-01

Supplemental feeding with corn to attract and manage deer is a common practice throughout Texas. Other species, including northern bobwhites (Colinus virginianus), are commonly seen feeding around supplemental deer feeders. In many cases, supplemental feeding continues year-round so feed supply stores always have supplemental corn in stock. Fluctuating weather and improper storage of corn can lead to and/or amplify aflatoxin contamination. Due to the recent decline of bobwhites throughout the Rolling Plains ecoregion of Texas, there has been interest in finding factors such as toxins that could be linked to their decline. In this study, we purchased and sampled supplemental corn from 19 locations throughout this ecoregion to determine if aflatoxin contamination was present in individual bags prior to being dispersed to wildlife. Of the 57 bags sampled, 33 bags (approximately 58%) contained aflatoxin with a bag range between 0.0-19.91 parts per billion (ppb). Additionally, three metal and three polypropylene supplemental feeders were each filled with 45.4 kg of triple cleaned corn and placed in an open field to study long-term aflatoxin buildup. Feeders were sampled every 3 months from November 2013-November 2014. Average concentration of aflatoxin over the year was 4.08 ± 2.53 ppb (±SE) in metal feeders, and 1.43 ± 0.89 ppb (±SE) in polypropylene feeders. The concentration of aflatoxins is not affected by the type of feeder (metal vs polypropylene), the season corn was sampled, and the location in the feeder (top, middle, bottom) where corn is sampled. It is unlikely that corn used in supplemental feeders is contributing to the bobwhite decline due to the low levels of aflatoxin found in purchased corn and long-term storage of corn used in supplemental feeders.

Ambient formaldehyde detection with a laser spectrometer based on difference-frequency generation in PPLN.

PubMed

Rehle, D; Leleux, D; Erdelyi, M; Tittel, F; Fraser, M; Friedfeld, S

2001-01-01

A laser spectrometer based on difference-frequency generation in periodically poled LiNbO3 (PPLN) has been used to quantify atmospheric formaldehyde with a detection limit of 0.32 parts per billion in a given volume (ppbV) using specifically developed data-processing techniques. With state-of-the-art fiber-coupled diode-laser pump sources at 1083 nm and 1561 nm, difference-frequency radiation has been generated in the 3.53-micrometers (2832-cm-1) spectral region. Formaldehyde in ambient air in the 1- to 10-ppb V range has been detected continuously for nine and five days at two separate field sites in the Greater Houston area operated by the Texas Natural Resource Conservation Commission (TNRCC) and the Houston Regional Monitoring Corporation (HRM). The acquired spectroscopic data are compared with results obtained by a well-established wet-chemical o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) technique.

Photoacoustic spectroscopy for chemical detection

NASA Astrophysics Data System (ADS)

Holthoff, Ellen L.; Pellegrino, Paul M.

2012-06-01

The Global War on Terror has made rapid detection and identification of chemical and biological agents a priority for Military and Homeland Defense applications. Reliable real-time detection of these threats is complicated by our enemy's use of a diverse range of materials. Therefore, an adaptable platform is necessary. Photoacoustic spectroscopy (PAS) is a useful monitoring technique that is well suited for trace detection of gaseous media. This method routinely exhibits detection limits at the parts-per-billion (ppb) or sub-ppb range. The versatility of PAS also allows for the investigation of solid and liquid analytes. Current research utilizes quantum cascade lasers (QCLs) in combination with an air-coupled solid-phase photoacoustic cell design for the detection of condensed phase material films deposited on a surface. Furthermore, variation of the QCL pulse repetition rate allows for identification and molecular discrimination of analytes based solely on photoacoustic spectra collected at different film depths.

Extraterrestrial Amino Acids in Orgueil and Ivuna: Tracing the Parent Body of CI Type Carbonaceous Chondrites

NASA Technical Reports Server (NTRS)

Meyer, Michael (Technical Monitor); Ehrenfreund, Pascale; Glavin, Daniel P.; Bota, Oliver; Cooper, George; Bada, Jeffrey

2001-01-01

Amino acid analyses using HPLC of pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna have found that beta-alanine, glycine, and gamma-amino-n-butyric acid (ABA) are the most abundant amino acids in these two meteorites, with concentrations ranging from approx. 600 to 2,000 parts per billion (ppb). Other alpha-amino acids such as alanine, alpha-ABA, alpha-aminoisobutyric acid (AIB), and isovaline are present only in trace amounts (less than 200 ppb). Carbon isotopic measurements of beta-alanine and glycine and the presence of racemic (D/L 1) alanine and beta-ABA in Orgueil suggest that these amino acids are extraterrestrial in origin. In comparison to the CM carbonaceous chondrites Murchison and Murray, the amino acid composition of the CIs is strikingly distinct, suggesting that these meteorites came from a different type of parent body, possibly an extinct comet, than did the CM carbonaceous chondrites.

Ambient formaldehyde detection with a laser spectrometer based on difference-frequency generation in PPLN

NASA Technical Reports Server (NTRS)

Rehle, D.; Leleux, D.; Erdelyi, M.; Tittel, F.; Fraser, M.; Friedfeld, S.

2001-01-01

A laser spectrometer based on difference-frequency generation in periodically poled LiNbO3 (PPLN) has been used to quantify atmospheric formaldehyde with a detection limit of 0.32 parts per billion in a given volume (ppbV) using specifically developed data-processing techniques. With state-of-the-art fiber-coupled diode-laser pump sources at 1083 nm and 1561 nm, difference-frequency radiation has been generated in the 3.53-micrometers (2832-cm-1) spectral region. Formaldehyde in ambient air in the 1- to 10-ppb V range has been detected continuously for nine and five days at two separate field sites in the Greater Houston area operated by the Texas Natural Resource Conservation Commission (TNRCC) and the Houston Regional Monitoring Corporation (HRM). The acquired spectroscopic data are compared with results obtained by a well-established wet-chemical o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) technique.

Airway diffusing capacity of nitric oxide and steroid therapy in asthma.

PubMed

Shin, Hye-Won; Rose-Gottron, Christine M; Cooper, Dan M; Newcomb, Robert L; George, Steven C

2004-01-01

Exhaled nitric oxide (NO) concentration is a noninvasive index for monitoring lung inflammation in diseases such as asthma. The plateau concentration at constant flow is highly dependent on the exhalation flow rate and the use of corticosteroids and cannot distinguish airway and alveolar sources. In subjects with steroid-naive asthma (n = 8) or steroid-treated asthma (n = 12) and in healthy controls (n = 24), we measured flow-independent NO exchange parameters that partition exhaled NO into airway and alveolar regions and correlated these with symptoms and lung function. The mean (+/-SD) maximum airway flux (pl/s) and airway tissue concentration [parts/billion (ppb)] of NO were lower in steroid-treated asthmatic subjects compared with steroid-naive asthmatic subjects (1,195 +/- 836 pl/s and 143 +/- 66 ppb compared with 2,693 +/- 1,687 pl/s and 438 +/- 312 ppb, respectively). In contrast, the airway diffusing capacity for NO (pl.s-1.ppb-1) was elevated in both asthmatic groups compared with healthy controls, independent of steroid therapy (11.8 +/- 11.7, 8.71 +/- 5.74, and 3.13 +/- 1.57 pl.s-1.ppb-1 for steroid treated, steroid naive, and healthy controls, respectively). In addition, the airway diffusing capacity was inversely correlated with both forced expired volume in 1 s and forced vital capacity (%predicted), whereas the airway tissue concentration was positively correlated with forced vital capacity. Consistent with previously reported results from Silkoff et al. (Silkoff PE, Sylvester JT, Zamel N, and Permutt S, Am J Respir Crit Med 161: 1218-1228, 2000) that used an alternate technique, we conclude that the airway diffusing capacity for NO is elevated in asthma independent of steroid therapy and may reflect clinically relevant changes in airways.

2013 Flood Waters "Flush" Pharmaceuticals and other Contaminants of Emerging Concern into the Water and Sediment of the South Platte River, Colorado

NASA Astrophysics Data System (ADS)

Battaglin, W. A.; Bradley, P. M.; Paschke, S.; Plumlee, G. S.; Kimbrough, R.

2016-12-01

In September 2013, heavy rainfall caused severe flooding in Rocky Mountain National Park (ROMO) and environs extending downstream into the main stem of the South Platte River. In ROMO, flooding damaged infrastructure and local roads. In the tributary canyons, flooding damaged homes, septic systems, and roads. On the plains, flooding damaged several wastewater treatment plants. The occurrence and fate of pharmaceuticals and other contaminants of emerging concern (CECs) in streams during flood conditions is poorly understood. We assessed the occurrence and fate of CECs in this flood by collecting water samples (post-peak flow) from 4 headwaters sites in ROMO, 7 sites on tributaries to the South Platte River, and 6 sites on the main stem of the South Platte; and by collecting flood sediment samples (post-flood depositional) from 14 sites on tributaries and 10 sites on the main stem. Water samples were analysed for 110 pharmaceuticals and 69 wastewater indicators. Sediment samples were analysed for 57 wastewater indicators. Concentrations and numbers of CECs detected in water increased markedly as floodwaters moved downstream and some were not diluted despite the large flow increases in downstream reaches of the affected rivers. For example, in the Cache la Poudre River in ROMO, no pharmaceuticals and 1 wastewater indicator compound (camphor) were detected. At Greeley, the Cache la Poudre was transporting 19 pharmaceuticals [total concentration of 0.69 parts-per-billion (ppb)] and 22 wastewater indicators (total concentration of 2.81 ppb). In the South Platte downstream from Greeley, 24 pharmaceuticals (total concentration of 1.47 ppb) and 24 wastewater indicators (total concentration of 2.35 ppb) were detected. Some CECs such as the combustion products pyrene, fluoranthene, and benzo(a)pyrene were detected only at sub-ppb concentrations in water, but were detected at concentrations in the hundreds of ppb in flood sediment samples.

Lead contamination of chicken eggs and tissues from a small farm flock.

PubMed

Trampel, Darrell W; Imerman, Paula M; Carson, Thomas L; Kinker, Julie A; Ensley, Steve M

2003-09-01

Twenty mixed-breed adult laying hens from a small farm flock in Iowa were clinically normal but had been exposed to chips of lead-based paint in their environment. These chickens were brought to the Iowa State University Veterinary Diagnostic Laboratory, Ames, Iowa, where the concentration of lead in blood, eggs (yolk, albumen, and shell), and tissues (liver, kidney, muscle, and ovary) from 5 selected chickens was determined over a period of 9 days. Blood lead levels ranged from less than 50 to 760 ppb. Lead contamination of the yolks varied from less than 20 to 400 ppb, and shells were found to contain up to 450 ppb lead. Albumen contained no detectable amount. Lead content of the egg yolks strongly correlated with blood lead levels. Deposition of lead in the shells did not correlate well with blood lead levels. Mean tissue lead accumulation was highest in kidneys (1,360 ppb), with livers ranking second (500 ppb) and ovarian tissue third (320 ppb). Muscle contained the lowest level of lead (280 ppb). Lead contamination of egg yolks and edible chicken tissues represents a potential public health hazard, especially to children repeatedly consuming eggs from contaminated family-owned flocks.

Use of primary cultures of Kenyon cells from bumblebee brains to assess pesticide side effects.

PubMed

Wilson, Daniel E; Velarde, Rodrigo A; Fahrbach, Susan E; Mommaerts, Veerle; Smagghe, Guy

2013-09-01

Bumblebees are important pollinators in natural and agricultural ecosystems. The latter results in the frequent exposure of bumblebees to pesticides. We report here on a new bioassay that uses primary cultures of neurons derived from adult bumblebee workers to evaluate possible side-effects of the neonicotinoid pesticide imidacloprid. Mushroom bodies (MBs) from the brains of bumblebee workers were dissected and dissociated to produce cultures of Kenyon cells (KCs). Cultured KCs typically extend branched, dendrite-like processes called neurites, with substantial growth evident 24-48 h after culture initiation. Exposure of cultured KCs obtained from newly eclosed adult workers to 2.5 parts per billion (ppb) imidacloprid, an environmentally relevant concentration of pesticide, did not have a detectable effect on neurite outgrowth. By contrast, in cultures prepared from newly eclosed adult bumblebees, inhibitory effects of imidacloprid were evident when the medium contained 25 ppb imidacloprid, and no growth was observed at 2,500 ppb. The KCs of older workers (13-day-old nurses and foragers) appeared to be more sensitive to imidacloprid than newly eclosed adults, as strong effects on KCs obtained from older nurses and foragers were also evident at 2.5 ppb imidacloprid. In conclusion, primary cultures using KCs of bumblebee worker brains offer a tool to assess sublethal effects of neurotoxic pesticides in vitro. Such studies also have the potential to contribute to the understanding of mechanisms of plasticity in the adult bumblebee brain. © 2013 Wiley Periodicals, Inc.

Uranium hydrogeochemical and stream sediment reconnaissance of the Trinidad NTMS Quadrangle, Colorado

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morris, W.A.; LaDelfe, C.M.; Weaver, T.A.

1978-10-01

During the field seasons of 1976 and 1977, 1,060 natural water and 1,240 waterborne sediment samples were collected from 1,768 locations in the Trinidad, Colorado, NTMS quadrangle. The samples from this 19,600-km/sup 2/ area were analyzed at the Los Alamos Scientific Laboratory for total uranium. The uranium concentrations in waters ranged from less than the detection limit of 0.02 parts per billion (ppb) to 88.3 ppb, with a mean value of 4.05 ppb. The concentrations in sediments ranged from 1.3 parts per million (ppM) to 721.9 ppM, with a mean value of 5.55 ppM. Based on simple statistical analyses ofmore » these data, arbitrary anomaly thresholds were set at 20 ppb for water samples and 12 ppM for sediment samples. By this definition, fifty-eight water and 39 sediment samples were considered anomalous. At least five areas delineated by the data appear to warrant more detailed investigations. Twenty-six anomalous water samples outline a broad area corresponding to the axis of the Apishapa uplift, seven others form a cluster in Huerfano Park, and five others outline a small area in the northern part of the San Luis Valley. Twenty-three anomalous sediment samples outline an area corresponding generally to Precambrian metamorphic rocks in the Culebra Range, and seven anomalous sediment samples form a cluster near Crestone Peak in the Sangre de Cristo Mountains.« less

Association of Ozone Exposure With Cardiorespiratory Pathophysiologic Mechanisms in Healthy Adults.

PubMed

Day, Drew B; Xiang, Jianbang; Mo, Jinhan; Li, Feng; Chung, Mingkei; Gong, Jicheng; Weschler, Charles J; Ohman-Strickland, Pamela A; Sundell, Jan; Weng, Wenguo; Zhang, Yinping; Zhang, Junfeng Jim

2017-09-01

Exposure to ozone has been associated with cardiovascular mortality, but the underlying biological mechanisms are not yet understood. To examine the association between ozone exposure and cardiopulmonary pathophysiologic mechanisms. A longitudinal study involving 89 healthy adult participants living on a work campus in Changsha City, China, was conducted from December 1, 2014, to January 31, 2015. This unique quasiexperimental setting allowed for better characterization of air pollutant exposure effects because the participants spent most of their time in controlled indoor environments. Concentrations of indoor and outdoor ozone, along with the copollutants particulate matter, nitrogen dioxide, and sulfur dioxide, were monitored throughout the study period and then combined with time-activity information and filtration conditions of each residence and office to estimate 24-hour and 2-week combined indoor and outdoor mean exposure concentrations. Associations between each exposure measure and outcome measure were analyzed using single-pollutant and 2-pollutant linear mixed models controlling for ambient temperature, secondhand smoke exposure, and personal-level time-varying covariates. Biomarkers indicative of inflammation and oxidative stress, arterial stiffness, blood pressure, thrombotic factors, and spirometry were measured at 4 sessions. Of the 89 participants, 25 (28%) were women and the mean (SD) age was 31.5 (7.6) years. The 24-hour ozone exposure concentrations ranged from 1.4 to 19.4 parts per billion (ppb), corresponding to outdoor concentrations ranging from 4.3 to 47.9 ppb. Within this range, in models controlling for a second copollutant and other potential confounders, a 10-ppb increase in 24-hour ozone was associated with mean increases of 36.3% (95% CI, 29.9%-43.0%) in the level of platelet activation marker soluble P-selectin, 2.8% (95% CI, 0.6%-5.1%) in diastolic blood pressure, 18.1% (95% CI, 4.5%-33.5%) in pulmonary inflammation markers fractional exhaled nitric oxide, and 31.0% (95% CI, 0.2%-71.1%) in exhaled breath condensate nitrite and nitrate as well as a -9.5% (95% CI, -17.7% to -1.4%) decrease in arterial stiffness marker augmentation index. A 10-ppb increase in 2-week ozone was associated with increases of 61.1% (95% CI, 37.8%-88.2%) in soluble P-selectin level and 126.2% (95% CI, 12.1%-356.2%) in exhaled breath condensate nitrite and nitrate level. Other measured biomarkers, including spirometry, showed no significant associations with either 24-hour ozone or 2-week ozone exposures. Short-term ozone exposure at levels not associated with lung function changes was associated with platelet activation and blood pressure increases, suggesting a possible mechanism by which ozone may affect cardiovascular health.

Metal levels in flathead sole (Hippoglossoides elassodon) and great sculpin (Myoxocephalus polyacanthocephalus) from Adak Island, Alaska: Potential risk to predators and fishermen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Burger, Joanna; Gochfeld, Michael; Environmental and Occupational Medicine, UMDNJ-Robert Wood Johnson Medical School, Piscataway, NJ 08854

2007-01-15

Increasingly there is a need to assess the contaminant levels in fish as indicators of the health and well-being of both the fish and their consumers, including humans. This paper examines the levels of arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the kidney, liver, and muscle of great sculpin and flathead sole from Adak Island in the Aleutian Islands, Alaska. Both species are consumed by the local Aleuts and others. There were significant differences in the levels of heavy metals as a function of tissue for both fish species; the liver of sculpin and sole generally had themore » highest levels of most metals, except for arsenic, lead, and selenium. Sole had significantly higher mean levels of arsenic in kidney (32,384 vs. 531 ppb, wet weight), liver (18,954 vs. 2532 ppb), and muscle (19,452 vs. 1343 ppb) than did sculpin. Sole also had higher mean levels of cadmium (230 vs. 63 ppb), lead (1236 vs. 48 ppb), mercury (150 vs. 107 ppb), and selenium (5215 vs. 1861 ppb) in kidney than did sculpin. There were significant correlations among weight and length measurements for both species. However, except for mercury, there were few significant correlations among tissue types for most metals. Only mercury and manganese levels were significantly correlated with size for sculpin (but not for sole). Levels of arsenic, lead, and mercury may pose a risk to predators that consume them, and arsenic and mercury may pose a risk to human consumers.« less

Carbon Nanotube Electrode Arrays For Enhanced Chemical and Biological Sensing

NASA Technical Reports Server (NTRS)

Han, Jie

2003-01-01

Applications of carbon nanotubes for ultra-sensitive electrical sensing of chemical and biological species have been a major focus in NASA Ames Center for Nanotechnology. Great progress has been made toward controlled growth and chemical functionalization of vertically aligned carbon nanotube arrays and integration into micro-fabricated chip devices. Carbon nanotube electrode arrays devices have been used for sub-attomole detection of DNA molecules. Interdigitated carbon nanotubes arrays devices have been applied to sub ppb (part per billion) level chemical sensing for many molecules at room temperature. Stability and reliability have also been addressed in our device development. These results show order of magnitude improvement in device performance, size and power consumption as compared to micro devices, promising applications of carbon nanotube electrode arrays for clinical molecular diagnostics, personal medical testing and monitoring, and environmental monitoring.

Chip Scale Ultra-Stable Clocks: Miniaturized Phonon Trap Timing Units for PNT of CubeSats

NASA Technical Reports Server (NTRS)

Rais-Zadeh, Mina; Altunc, Serhat; Hunter, Roger C.; Petro, Andrew

2016-01-01

The Chip Scale Ultra-Stable Clocks (CSUSC) project aims to provide a superior alternative to current solutions for low size, weight, and power timing devices. Currently available quartz-based clocks have problems adjusting to the high temperature and extreme acceleration found in space applications, especially when scaled down to match small spacecraft size, weight, and power requirements. The CSUSC project aims to utilize dual-mode resonators on an ovenized platform to achieve the exceptional temperature stability required for these systems. The dual-mode architecture utilizes a temperature sensitive and temperature stable mode simultaneously driven on the same device volume to eliminate ovenization error while maintaining extremely high performance. Using this technology it is possible to achieve parts-per-billion (ppb) levels of temperature stability with multiple orders of magnitude smaller size, weight, and power.

Electrospray Ionization/Ion Mobility Spectrometer/Cylindrical Ion Trap Mass Spectrometer System for In-Situ Detection of Organic Compounds

NASA Technical Reports Server (NTRS)

Kanik, I.; Johnson, P. V.; Beegle, L. W.; Cooks, R. G.; Laughlin, B. C.; Hill, H. H.

2003-01-01

The potential of an Electrospray Ionization/Ion Mobility Spectrometer/Cylindrical Ion Trap Mass Spectrometer (ESI/IMS/CIT-MS) as an analytical instrument for analyzing material extracted from rock and soil samples as part of a suite of instruments on the proposed 2009 Mars Science Lander (MSL) will be demonstrated. This instrument will be able to identify volatile compounds as well as resident organic molecules on the parts-per-billion (ppb) level. Also, it will be able to obtain an inventory of chemical species on the surface of Mars which will result in a better understanding of ongoing surface chemistry. Finally, questions relevant to biological processes will be answered with the complete inventory of surface and near surface organic molecules that the ESI/IMS/CIT is capable of performing.

Remediation of DNAPL through Sequential In Situ Chemical Oxidation and Bioaugmentation

DTIC Science & Technology

2009-04-01

Specific Electrode Field Field-filtered, ICP - PSC 0.05 mg/L 125 mL plastic nitric acid to pHɚ 28 days cool to 4oC Ion Chromatography 25310 C PSC 0.2...oxidized by MnO2 at a significant rate; however, MnO2 reacted rapidly with oxalic acid ; • Complete dechlorination occurred only in microcosms...controller PLFA phospholipid fatty acid ppb parts per billion PTA pilot test area PVC polyvinyl chloride QAPP quality assurance project plan QA

Treatability Studies of Tributyltin in Activated Sludge

DTIC Science & Technology

1989-12-01

per liter pg/L Picograms per liter ppb Parts per billion RREL Risk Reduction Engineering Laboratory TBT Tributyltin Chloride TKN Total Kjeldahl number...success of tributyltin ( TBT ) compounds in inhibiting the growth of marine organisms has led to their use as pesticides in marine antifouling paints...CONTROL -4- ANALINE 150 E a. 100 zw 50 50 0 1 2 3 4 5 6 7 8 TIME (DAYS) Fig. 6. Inhibition studies of tributyltin . 17 ANILINE (100 mg/I) + TBT (0.05 mg

Increased Femoral Head Offset is Associated With Elevated Metal Ions in Asymptomatic Patients With Metal-on-Polyethylene Total Hip Arthroplasty.

PubMed

Martin, John R; Camp, Christopher L; Wyles, Cody C; Taunton, Michael J; Trousdale, Robert T; Lewallen, David G

2016-12-01

Predisposing factors for trunnionosis and elevated metal ion levels in metal-on-polyethylene (MOP) total hip arthroplasty (THA) are currently unknown. This retrospective cohort study enrolled 80 consecutive patients (43 males) with an asymptomatic MOP THA at 2- to 5-year follow-up and no other metal implants. Serum cobalt (Co) and chromium (Cr) levels were collected at the time of enrollment, and retrospective review was performed regarding demographic, implant, and surgical characteristics. Mean age at the time of surgery was 65.7 years (range 35.6-85.9 years), and mean postoperative follow-up was 28.7 months (range 24.4-58.9 months). Femoral head offset was the only evaluated factor shown to increase serum Co ion levels above baseline within the cohort. Mean difference in Co level for high and low offset implants was 0.58 ppb (95% confidence interval [CI] = 0.05-1.11 ppb; P = .03). Mean difference in Cr level for high and low offset implants was 0.19 ppb (95% CI = -0.23 to 0.60 ppb; P = .37). Mean difference in Co level for small and large femoral heads was 0.20 ppb (95% CI = -0.41 to 0.81 ppb; P = .59). Mean difference in Cr level for small and large femoral heads was 0.28 ppb (95% CI = -0.18 to 0.74 ppb; P = .06). Age, gender, Harris Hip Score, and implant duration were not associated with changes in metal ion levels. Femoral head offset appears to be an important source of elevated metal ion levels in MOP THA. Further studies will be needed to understand if increasing femoral head offset is associated with subsequent adverse local tissue reactions. Copyright © 2016 Elsevier Inc. All rights reserved.

Perchlorate and Superfund Response to Uncertainty and the Geochemical Cycle

NASA Astrophysics Data System (ADS)

Mayer, K. P.

2007-12-01

Perchlorate, a chemical that had been known both in nature and through synthesis since the nineteenth century, only emerged into the limelight as an environmental contaminant in 1997. US EPA's Superfund Program became involved in perchlorate issues in the late 1980s and early 1990s due to the chemical's presence mixed with other contaminants at cleanup sites. Relying largely on pharmaceutical studies primarily from the 1950s and 1960s, EPA scientists in 1992 made a provisional estimate of toxicity and estimated that about 4 micrograms per liter (parts per billion or ppb) in drinking water would be protective. "Uncertainty factors" were incorporated to address for several identified information gaps. Results of new animal and human studies funded by the Defense Department and industry in the late 1990s shifted the concern from affects on adults with unhealthy thyroids to the potential developmental health risks to infants and children. EPA's January, 2002, draft toxicity assessment was referred to a committee of the National Research Council. In January, 2005, this committee recommended a "reference dose" based primarily on human clinical data. Many decisions remain on interpretation of the scientific recommendations for regulatory applications. After California's 1997 development of an analytical method to detect perchlorate in water to 4 ppb, EPA and state officials quickly discovered this chemical at 10 Superfund sites in the Pacific Southwest Region and at more than 30 other locations in California, Arizona and Nevada. Even before current research on the potential for natural sources of this anion, reported detections of perchlorate were investigated with reasonable care and appropriate skepticism. A brief overview of the search for likely sources of perchlorate detected in California water supplies is presented from a regional Superfund perspective. Some are clearly anthropogenic and others may be unrelated to industrial or disposal practices. Currently, there is no Federal standard for perchlorate. In March, 2004, California established Public Health Goal of 6 ppb in drinking water and a drinking water standard may be promulgated by November 2007. Seven other states have advisory levels ranging from 1 to 51 ppb.

A reactive and sensitive diffusion sampler for the determination of aldehydes and ketones in ambient air

NASA Astrophysics Data System (ADS)

Uchiyama, Shigehisa; Hasegawa, Shuji

We developed a diffusive sampling device (DSD-carbonyl) for organic carbonyl compounds (aldehydes and ketones) which is suitable for collection and analysis of low concentration levels. This sampling device is composed of three parts, an exposure part made of a porous polytetrafluoroethylene (PPTFE) tube, an analysis part made of polypropylene (PP) tubing and an absorbent part made of 2,4-dinitrophenylhydrazine (DNPH) coated silica gel (DNPH-silica). Aldehydes and ketones diffuse to the DSD-carbonyl through PPTFE-tube by the mechanism of molecular diffusion and react specifically with DNPH to form a stable DNPH-derivatives. Collection is controlled by moving the absorbent from the exposure part to the analysis part by changing the posture of the DSD-carbonyl. DNPH-derivatives were eluted from an analysis part of DSD-carbonyl with acetonitrile directly and analyzed by high performance liquid chromatography (HPLC). The advantages of the DSD-carbonyl are the following: (1) The DSD-carbonyl can be used in a wide range of concentration of aldehydes and ketones in atmosphere, as the DSD-carbonyl exposure part has a variable diffusion area, (2) DNPH-derivatives are eluted from DNPH-silica without contamination of air. (3) The sampler can be applied to active sampling by connecting it with a pump. The limit of detection (LOD) for concentrations of major aldehydes and ketones ranged from 0.072 to 0.13 ppb, and the limit of quantitation (LOQ) ranged from 0.24 to 0.42 ppb. The coefficient variation (CV) for concentrations of major aldehydes and ketones ranged from 2.5 to 3.0% in laboratory air. The DSD-carbonyl method and active sampling method (US EPA method IP-6A) showed a good correlation (formaldehyde, r2=0.995). The uptake rates for formaldehyde, acetaldehyde, and acetone were estimated as 0.078, 0.062 and 0.079 nmol ppb -1 h -1, respectively. It is possible to estimate atmospheric aldehydes and ketones at parts per billion (ppb), with high sensitivity and precision, by using DSD-carbonyl.

Diagnostic utility of fractional exhaled nitric oxide in prolonged and chronic cough according to atopic status.

PubMed

Asano, Takamitsu; Takemura, Masaya; Fukumitsu, Kensuke; Takeda, Norihisa; Ichikawa, Hiroya; Hijikata, Hisatoshi; Kanemitsu, Yoshihiro; Uemura, Takehiro; Takakuwa, Osamu; Ohkubo, Hirotsugu; Maeno, Ken; Ito, Yutaka; Oguri, Tetsuya; Nakamura, Atsushi; Niimi, Akio

2017-04-01

Cough-variant asthma (CVA) and cough-predominant asthma (CPA) are the major causes of persistent cough in Japan. The utility of fractional exhaled nitric oxide (FeNO) measurement in the differential diagnosis of persistent cough has been reported, but the influence of atopic status, which is associated with higher FeNO levels, on the diagnostic utility of FeNO has been unknown. We retrospectively analyzed 105 non-smoking patients with prolonged and chronic cough that were not treated with corticosteroids and anti-leukotrienes. CPA was diagnosed in 37 patients, CVA in 40, and non-asthmatic cough (NAC) in 28. FeNO levels were significantly higher in the CPA [35.8 (7.0-317.9) ppb] and CVA [24.9 (3.1-156.0) ppb] groups than in the NAC group [18.2 (6.9-49.0) ppb] (p < 0.01 by Kruskal-Wallis test). The optimal cut-off for distinguishing asthmatic cough (AC; CPA and CVA) from NAC was 29.2 ppb [area under the curve (AUC) 0.74, p < 0.01]. Ninety-one percent of subjects with FeNO levels ≥29.2 ppb had AC. Meanwhile, 40% of AC patients had FeNO levels <29.2 ppb. Stratified cut-off levels were 31.1 ppb (AUC 0.83) in atopic subjects vs. 19.9 ppb (AUC 0.65) in non-atopic subjects (p = 0.03 for AUC). Although high FeNO levels suggested the existence of AC, lower FeNO levels had limited diagnostic significance. Atopic status affects the utility of FeNO levels in the differential diagnosis of prolonged and chronic cough. Copyright © 2016 Japanese Society of Allergology. Production and hosting by Elsevier B.V. All rights reserved.

Perchlorate Contamination of Drinking Water: Regulatory Issues and Legislative Actions

DTIC Science & Technology

2006-11-29

water was thought to be contaminated. The FDA found perchlorate in roughly 90% of lettuce samples (average levels ranged from 11.9 ppb to 7.7 ppb for... lettuces in four states), and in 101 of 104 bottled milk samples (with an average level of 5.7 ppb across 14 states). 5 This research is relevant to

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, T.L.; George, W.E.; Hensley, W.K.

As part of the Hydrogeochemical and Stream Sediment Reconnaissance (HSSR) of the National Uranium Resource Evaluation (NURE) sponsored by the US Department of Energy (DOE), the Los Alamos Scientific Laboratory (LASL) conducted a detailed hydrogeochemical survey of well waters in a 4250-km/sup 2/ area near Pie Town in west-central New Mexico. A total of 300 well samples was collected and analyzed for uranium and 23 other elements. The results of these analyses and carbonate and bicarbonate ion concentrations are presented in the Appendixes of this report. Uranium concentrations range from below the detection limit of 0.02 parts per billion (ppB)more » to 293.18 ppB and average 8.71 ppB. Samples containing high levels of uranium were collected from the Largo Creek valley west of Quemado, from a small area about 6 km east of Quemado, from a small area surrounding Pie Town, and from scattered locations in the area surrounding Adams Diggings north of Pie Town. Most of the samples containing high uranium concentrations were collected from wells associated with the volcanic sedimentary facies of the Datil formation. This formation is a likely source of mobile uranium that may be precipitating in the underlying Baca formation, a known uranium host unit. Bicarbonate ion concentration, while proportional to uranium concentration in some cases, is not a strong controlling factor in the uranium concentrations in samples from this area.« less

Exhaled ethane concentration in patients with cancer of the upper gastrointestinal tract - a proof of concept study.

PubMed

Abela, Jo Etienne; Skeldon, Kenneth D; Stuart, Robert C; Padgett, Miles J

2009-06-01

There has been growing interest in the measurement of breath ethane as an optimal non-invasive marker of oxidative stress. High concentrations of various breath alkanes including ethane have been reported in a number of malignancies. Our aim was to investigate the use of novel laser spectroscopy for rapid reporting of exhaled ethane and to determine whether breath ethane concentration is related to a diagnosis of upper gastrointestinal malignancy. Two groups of patients were recruited. Group A (n = 20) had a histo-pathological diagnosis of either esophageal or gastric malignancy. Group B (n = 10) was made up of healthy controls. Breath samples were collected from these subjects and the ethane concentration in these samples was subsequently measured to an accuracy of 0.2 parts per billion, ppb. Group A patients had a corrected exhaled breath ethane concentration of 2.3 +/- 0.8 (mean +/- SEM) ppb. Group B patients registered a mean of 3.1 +/- 0.5 ppb. There was no statistically significant difference between the two groups (p = 0.39). In conclusion, concentrations of ethane in collected breath samples were not significantly elevated in upper gastrointestinal malignancy. The laser spectroscopy system provided a reliable and rapid turnaround for breath sample analysis.

Detecting Airborne Mercury by Use of Gold Nanowires

NASA Technical Reports Server (NTRS)

Ryan, Margaret; Shevade, Abhijit; Kisor, Adam; Homer, Margie; Soler, Jessica; Mung, Nosang; Nix, Megan

2009-01-01

Like the palladium chloride (PdCl2) films described in the immediately preceding article, gold nanowire sensors have been found to be useful for detecting airborne elemental mercury at concentrations on the order of parts per billion (ppb). Also like the PdCl2 films, gold nanowire sensors can be regenerated under conditions much milder than those necessary for regeneration of gold films that have been used as airborne-Hg sensors. The interest in nanowire sensors in general is prompted by the expectation that nanowires of a given material covering a given surface may exhibit greater sensitivity than does a film of the same material because nanowires have a greater surface area. In preparation for experiments to demonstrate this sensor concept, sensors were fabricated by depositing gold nanowires, variously, on microhotplate or microarray sensor substrates. In the experiments, the electrical resistances were measured while the sensors were exposed to air at a temperature of 25 C and relative humidity of about 30 percent containing mercury at various concentrations from 2 to 70 ppb (see figure). The results of this and other experiments have been interpreted as signifying that sensors of this type can detect mercury at ppb concentrations in room-temperature air and can be regenerated by exposure to clean flowing air at temperatures <40 C.

DPASV analytical technique for ppb level uranium analysis

NASA Astrophysics Data System (ADS)

Pal, Sangita; Singha, Mousumi; Meena, Sher Singh

2018-04-01

Determining uranium in ppb level is considered to be most crucial for reuse of water originated in nuclear industries at the time of decontamination of plant effluents generated during uranium (fuel) production, fuel rod fabrication, application in nuclear reactors and comparatively small amount of effluents obtained during laboratory research and developmental work. Higher level of uranium in percentage level can be analyzed through gravimetry, titration etc, whereas inductively coupled plasma-atomic energy spectroscopy (ICP-AES), fluorimeter are well suited for ppm level. For ppb level of uranium, inductively coupled plasma - mass spectroscopy (ICP-MS) or Differential Pulse Anodic Stripping Voltammetry (DPASV) serve the purpose. High precision, accuracy and sensitivity are the crucial for uranium analysis in trace (ppb) level, which are satisfied by ICP-MS and stripping voltammeter. Voltammeter has been found to be less expensive, requires low maintenance and is convenient for measuring uranium in presence of large number of other ions in the waste effluent. In this paper, necessity of uranium concentration quantification for recovery as well as safe disposal of plant effluent, working mechanism of voltammeter w.r.t. uranium analysis in ppb level with its standard deviation and a data comparison with ICP-MS has been represented.

Detection and Spatial Mapping of Mercury Contamination in Water Samples Using a Smart-Phone

PubMed Central

2014-01-01

Detection of environmental contamination such as trace-level toxic heavy metal ions mostly relies on bulky and costly analytical instruments. However, a considerable global need exists for portable, rapid, specific, sensitive, and cost-effective detection techniques that can be used in resource-limited and field settings. Here we introduce a smart-phone-based hand-held platform that allows the quantification of mercury(II) ions in water samples with parts per billion (ppb) level of sensitivity. For this task, we created an integrated opto-mechanical attachment to the built-in camera module of a smart-phone to digitally quantify mercury concentration using a plasmonic gold nanoparticle (Au NP) and aptamer based colorimetric transmission assay that is implemented in disposable test tubes. With this smart-phone attachment that weighs <40 g, we quantified mercury(II) ion concentration in water samples by using a two-color ratiometric method employing light-emitting diodes (LEDs) at 523 and 625 nm, where a custom-developed smart application was utilized to process each acquired transmission image on the same phone to achieve a limit of detection of ∼3.5 ppb. Using this smart-phone-based detection platform, we generated a mercury contamination map by measuring water samples at over 50 locations in California (USA), taken from city tap water sources, rivers, lakes, and beaches. With its cost-effective design, field-portability, and wireless data connectivity, this sensitive and specific heavy metal detection platform running on cellphones could be rather useful for distributed sensing, tracking, and sharing of water contamination information as a function of both space and time. PMID:24437470

A Room Temperature Nitric Oxide Gas Sensor Based on a Copper-Ion-Doped Polyaniline/Tungsten Oxide Nanocomposite

PubMed Central

Wang, Shih-Han; Shen, Chi-Yen; Su, Jian-Ming; Chang, Shiang-Wen

2015-01-01

The parts-per-billion-level nitric oxide (NO) gas sensing capability of a copper-ion-doped polyaniline/tungsten oxide nanocomposite (Cu2+/PANI/WO3) film coated on a Rayleigh surface acoustic wave device was investigated. The sensor developed in this study was sensitive to NO gas at room temperature in dry nitrogen. The surface morphology, dopant distribution, and electric properties were characterized using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, and Hall effect measurements, respectively. The Cu2+/PANI/WO3 film exhibited high NO gas sensitivity and selectivity as well as long-term stability. At 1 ppb of NO, a signal with a frequency shift of 4.3 ppm and a signal-to-noise ratio of 17 was observed. The sensor exhibited distinct selectivity toward NO gas with no substantial response to O2, NH3 and CO2 gases. PMID:25811223

TRACE ELEMENT ANALYSES OF URANIUM MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beals, D; Charles Shick, C

The Savannah River National Laboratory (SRNL) has developed an analytical method to measure many trace elements in a variety of uranium materials at the high part-per-billion (ppb) to low part-per-million (ppm) levels using matrix removal and analysis by quadrapole ICP-MS. Over 35 elements were measured in uranium oxides, acetate, ore and metal. Replicate analyses of samples did provide precise results however none of the materials was certified for trace element content thus no measure of the accuracy could be made. The DOE New Brunswick Laboratory (NBL) does provide a Certified Reference Material (CRM) that has provisional values for a seriesmore » of trace elements. The NBL CRM were purchased and analyzed to determine the accuracy of the method for the analysis of trace elements in uranium oxide. These results are presented and discussed in the following paper.« less

Prototype development and test results of a continuous ambient air monitoring system for hydrazine at the 10 ppb level

NASA Technical Reports Server (NTRS)

Meneghelli, Barry; Parrish, Clyde; Barile, Ron; Lueck, Dale E.

1995-01-01

A Hydrazine Vapor Area Monitor (HVAM) system is currently being field tested as a detector for the presence of hydrazine in ambient air. The MDA/Polymetron Hydrazine Analyzer has been incorporated within the HVAM system as the core detector. This analyzer is a three-electrode liquid analyzer typically used in boiler feed water applications. The HVAM system incorporates a dual-phase sample collection/transport method which simultaneously pulls ambient air samples containing hydrazine and a very dilute sulfuric acid solution (0.0001 M) down a length of 1/4 inch outside diameter (OD) tubing from a remote site to the analyzer. The hydrazine-laden dilute acid stream is separated from the air and the pH is adjusted by addition of a dilute caustic solution to a pH greater than 10.2 prior to analysis. Both the dilute acid and caustic used by the HVAM are continuously generated during system operation on an "as needed" basis by mixing a metered amount of concentrated acid/base with dilution water. All of the waste water generated by the analyzer is purified for reuse by Barnstead ion-exchange cartridges so that the entire system minimizes the generation of waste materials. The pumping of all liquid streams and mixing of the caustic solution and dilution water with the incoming sample are done by a single pump motor fitted with the appropriate mix of peristaltic pump heads. The signal to noise (S/N) ratio of the analyzer has been enhanced by adding a stirrer in the MDA liquid cell to provide mixing normally generated by the high liquid flow rate designed by the manufacturer. An onboard microprocessor continuously monitors liquid levels, sample vacuum, and liquid leak sensors, as well as handles communications and other system functions (such as shut down should system malfunctions or errors occur). The overall system response of the HVAM can be automatically checked at regular intervals by measuring the analyzer response to a metered amount of calibration standard injected into the dilute acid stream. The HVAM system provides two measurement ranges (threshold limit value (TLV): 10 to 1000 parts per billion (ppb)/LEAK: 100 ppb to 10 parts per million (ppm)). The LEAK range is created by dilution of the sulfuric acid/hydrazine liquid sample with pure water. This dual range capability permits the analyzer to quantify ambient air samples whose hydrazine concentrations range from 10 ppb to as high as 10 ppm. The laboratory and field prototypes have demonstrated total system response times on the order of 10 to 12 minutes for samples ranging from 10 to 900 ppb in the lLV mode and is greater than 2 minutes for samples ranging from 100 to 1300 ppb in the LEAK mode. Service intervals of over 3 months have been demonstrated for continuous 24 hour/day, 7 day/week usage. The HVAM is made up of a purged cabinet that contains power supplies, RS422 signal transmission capabilities, a UPS, an on-site warning system, and a Line Replaceable Unit (LRU). The LRU includes all of the liquid flow system, the analyzer, the control/data system microprocessor and assorted flow and liquid-level sensors. The LRU is mounted on a track slide system so it can be serviced inplace or totally removed and quickly exchanged with another calibrated unit, thus minimizing analyzer downtime. Once an LRU is removed from an analyzer enclosure, it can be brought to a laboratory facility for complete calibration and periodic maintenance.

Performance of a new hand-held device for exhaled nitric oxide measurement in adults and children.

PubMed

Alving, K; Janson, C; Nordvall, L

2006-04-20

Exhaled nitric oxide (NO) measurement has been shown to be a valuable tool in the management of patients with asthma. Up to now, most measurements have been done with stationary, chemiluminescence-based NO analysers, which are not suitable for the primary health care setting. A hand-held NO analyser which simplifies the measurement would be of value both in specialized and primary health care. In this study, the performance of a new electrochemical hand-held device for exhaled NO measurements (NIOX MINO) was compared with a standard stationary chemiluminescence unit (NIOX). A total of 71 subjects (6-60 years; 36 males), both healthy controls and atopic patients with and without asthma were included. The mean of three approved exhalations (50 ml/s) in each device, and the first approved measurement in the hand-held device, were compared with regard to NO readings (Bland-Altman plots), measurement feasibility (success rate with 6 attempts) and repeatability (intrasubject SD). Success rate was high (> or = 84%) in both devices for both adults and children. The subjects represented a FENO range of 8-147 parts per billion (ppb). When comparing the mean of three measurements (n = 61), the median of the intrasubject difference in exhaled NO for the two devices was -1.2 ppb; thus generally the hand-held device gave slightly higher readings. The Bland-Altman plot shows that the 95% limits of agreement were -9.8 and 8.0 ppb. The intrasubject median difference between the NIOX and the first approved measurement in the NIOX MINO was -2.0 ppb, and limits of agreement were -13.2 and 10.2 ppb. The median repeatability for NIOX and NIOX MINO were 1.1 and 1.2 ppb, respectively. The hand-held device (NIOX MINO) and the stationary system (NIOX) are in clinically acceptable agreement both when the mean of three measurements and the first approved measurement (NIOX MINO) is used. The hand-held device shows good repeatability, and it can be used successfully on adults and most children. The new hand-held device will enable the introduction of exhaled NO measurements into the primary health care.

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

DOE PAGES

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; ...

2015-10-21

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO 2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ~10 15 cm -2 for the 4.8-nm-thick PNSmore » when exposed to 20 p.p.b. NO 2 at 300 K. As a result, our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm).« less

Summary of airborne chlorine and hydrogen chloride gas measurements for August 20 and September 5, 1977 Voyager launches at Air Force Eastern Test Range, Florida

NASA Technical Reports Server (NTRS)

Gregory, G. L.; Emerson, B. R., Jr.; Hudgins, C. H.

1978-01-01

Airborne chlorine and hydrogen chloride measurements were made in the tropospheric ground cloud following the Voyager launches of August 20 and September 5, 1977. The maximum observed hydrogen chloride concentration for both launches was about 25 to 30 parts per million (ppm) occurring typically 2 to 6 minutes after launch. By completion of the sampling mission (1-1/2 hours for August, 4-1/2 hours for September), the maximum in-cloud concentration decayed to about 1 to 2 ppm. Maximum observed chlorine concentrations were about 40 to 55 parts per billion (ppb) about 2 to 8 minutes after launch; by about 15 minutes after launch, chlorine concentrations were less than 10 ppb (detection limit). In-cloud chlorine concentrations were well below 1 percent of hydrogen chloride concentrations. The appendix of the report discusses the chlorine instrument and the laboratory evaluation of the detector.

Extraterrestrial amino acids in Orgueil and Ivuna: Tracing the parent body of CI type carbonaceous chondrites

PubMed Central

Ehrenfreund, Pascale; Glavin, Daniel P.; Botta, Oliver; Cooper, George; Bada, Jeffrey L.

2001-01-01

Amino acid analyses using HPLC of pristine interior pieces of the CI carbonaceous chondrites Orgueil and Ivuna have found that β-alanine, glycine, and γ-amino-n-butyric acid (ABA) are the most abundant amino acids in these two meteorites, with concentrations ranging from ≈600 to 2,000 parts per billion (ppb). Other α-amino acids such as alanine, α-ABA, α-aminoisobutyric acid (AIB), and isovaline are present only in trace amounts (<200 ppb). Carbon isotopic measurements of β-alanine and glycine and the presence of racemic (D/L ≈ 1) alanine and β-ABA in Orgueil suggest that these amino acids are extraterrestrial in origin. In comparison to the CM carbonaceous chondrites Murchison and Murray, the amino acid composition of the CIs is strikingly distinct, suggesting that these meteorites came from a different type of parent body, possibly an extinct comet, than did the CM carbonaceous chondrites. PMID:11226205

Ultrahigh sensitivity and layer-dependent sensing performance of phosphorene-based gas sensors

NASA Astrophysics Data System (ADS)

Cui, Shumao; Pu, Haihui; Wells, Spencer A.; Wen, Zhenhai; Mao, Shun; Chang, Jingbo; Hersam, Mark C.; Chen, Junhong

2015-10-01

Two-dimensional (2D) layered materials have attracted significant attention for device applications because of their unique structures and outstanding properties. Here, a field-effect transistor (FET) sensor device is fabricated based on 2D phosphorene nanosheets (PNSs). The PNS sensor exhibits an ultrahigh sensitivity to NO2 in dry air and the sensitivity is dependent on its thickness. A maximum response is observed for 4.8-nm-thick PNS, with a sensitivity up to 190% at 20 parts per billion (p.p.b.) at room temperature. First-principles calculations combined with the statistical thermodynamics modelling predict that the adsorption density is ~1015 cm-2 for the 4.8-nm-thick PNS when exposed to 20 p.p.b. NO2 at 300 K. Our sensitivity modelling further suggests that the dependence of sensitivity on the PNS thickness is dictated by the band gap for thinner sheets (<10 nm) and by the effective thickness on gas adsorption for thicker sheets (>10 nm).

Gas Chromatic Mass Spectrometer

NASA Technical Reports Server (NTRS)

Wey, Chowen

1995-01-01

Gas chromatograph/mass spectrometer (GC/MS) used to measure and identify combustion species present in trace concentration. Advanced extractive diagnostic method measures to parts per billion (PPB), as well as differentiates between different types of hydrocarbons. Applicable for petrochemical, waste incinerator, diesel transporation, and electric utility companies in accurately monitoring types of hydrocarbon emissions generated by fuel combustion, in order to meet stricter environmental requirements. Other potential applications include manufacturing processes requiring precise detection of toxic gaseous chemicals, biomedical applications requiring precise identification of accumulative gaseous species, and gas utility operations requiring high-sensitivity leak detection.

Superfund Record of Decision Amendment (EPA Region 6): Texarkana Wood Preserving Co. , Texarkana, TX, March 13, 1998

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

This decision document presents an amendment to the selected remedial action for the Texarkana Wood Preserving Co. Superfund Site. This amendment fundamentally changes the Record of Decision (ROD) executed by the Regional Administrator on September 25, 1990. This amended remedy will seal and contain soils contaminated with greater than 3 ppm (parts per million) benzo(a)pyrene equivalents, 2450 ppm total poly aromatic hydrocarbons (PAH), 20 ppb (parts per billion) as 2,3,7,8 TCDD equivalents and 150 ppm pentachlorophenol beneath a soil cap.

Relations between total phosphorus and orthophosphorus concentrations and rainfall, surface-water discharge, and groundwater levels in Big Cypress Seminole Indian Reservation, Florida, 2014–16

USGS Publications Warehouse

McBride, W. Scott; Sifuentes, Dorothy F.

2018-02-06

The Seminole Tribe of Florida (the Tribe) is partnering with the U.S. Environmental Protection Agency to develop a numeric phosphorus criterion for the 52,000-acre Big Cypress Seminole Indian Reservation (BCSIR), which is located downgradient of the Everglades Agricultural Area, and of other public and private lands, in southeastern Hendry County and northwestern Broward County in southern Florida. The U.S. Geological Survey (USGS), in cooperation with the Tribe, used water-quality data collected between October 2014 and September 2016 by the Tribe and the South Florida Water Management District (SFWMD), along with data from rainfall gages, surface-water stage and discharge gages, and groundwater monitoring wells, to (1) examine the relations between local hydrology and measured total phosphorus (TP) and orthophosphorus (OP) concentrations and (2) identify explanatory variables for TP concentrations. Of particular concern were conditions when TP exceeded 10 parts per billion (ppb) (0.01 milligram per liter [mg/L]) given that the State of Florida and the Miccosukee Tribe of Indians Alligator Alley Reservation (located downstream of the BCSIR) have adopted a 10-ppb maximum TP criterion for surface waters.From October 2014 to September 2016, the Tribe collected 47–52 samples at each of nine water-quality sites for analysis of TP and OP, except at one site where 28 samples were collected. For all sites sampled, concentrations of TP (as phosphorus [P]) ranged from less than 0.002 mg/L (2 ppb) to a maximum of nearly 0.50 mg/L (500 ppb), whereas concentrations of OP (as P), the reactive form of inorganic phosphorus readily absorbed by plants and (or) abiotically absorbed, ranged from less than 0.003 mg/L (3 ppb) to a maximum of 0.24 mg/L (240 ppb). The median and interquartile ranges of concentrations of TP and OP in the samples collected in 2014–16 by the Tribe were similar to the median and interquartile ranges of concentrations in samples collected by the SFWMD at nearby sites during the same period. Differences in concentrations can likely be explained by differences in sample collection methods, sampling locations, sample collection time, and the hydrology during sampling or by the number of samples collected. A major limitation of this study was the short duration of sample collection, which covers a limited range of hydrologic conditions within the BCSIR.The effect of surface-water and groundwater hydrologic conditions on TP and OP concentrations was assessed by using rainfall data and surface-water stage and discharge records. The highest TP and OP concentrations occurred during peak surface-water flows in the canals following long dry periods. Concentrations of TP and OP increased internal to the BCSIR in the western half of the BCSIR during wet periods, but increased concentrations tended to lag behind rainfall events, likely because control structures upstream of sampling sites do not release flows until the water levels in the canals reach predetermined levels. This pattern may indicate that bed sediments in the canals contain high concentrations of phosphorus that becomes resuspended during high flows or that phosphorus salts that had accumulated on dry land during dry periods are carried into the canals by runoff. The largest TP spikes usually occurred at the beginning of high-flow events, but then quickly tapered off even when flows remained high.Groundwater flows were assessed in the BCSIR by using groundwater level observations from two preexisting USGS monitoring well clusters, each characterized by a shallow well installed in the surficial aquifer system and a deeper well installed in the intermediate aquifer system. Groundwater levels were evaluated with respect to surface-water levels and discharge in the BCSIR during the period of surface-water sampling. During dry conditions water levels in canals were often higher than groundwater levels in the surficial aquifer, indicating the potential for surface water to recharge the surficial aquifer. During wetter conditions, this trend reversed, and there was potential for shallow groundwater discharge into the canals.From October 2014 to September 2016, concentrations of TP tended to decrease as surface-water inflows moved across the BCSIR from north to south. In both the western and eastern halves of the reservation, the mean concentration of TP was lower in the surface-water outflows from the BCSIR than in the inflows. The mean concentration of TP in the inflows to the western reservation was 0.04 mg/L (40 ppb), whereas the mean concentration of TP in the outflows was 0.03 mg/L (30 ppb). In the eastern reservation, the mean concentration of TP in the inflows was 0.07 mg/L (70 ppb), whereas the mean concentration of TP in the outflows was 0.04 mg/L (40 ppb).TP and OP concentrations were evaluated relative to other water-quality parameters, including turbidity, suspended solids, nitrate plus nitrite, dissolved oxygen, pH, and specific conductance, to determine if any relations existed between TP and other variables. Weak relations were indicated for turbidity and suspended solids at two sites, which indicates that there may be a relation of increased TP to mobilization of sediment.

Exhaled nitric oxide in a population-based study of asthma and allergy in schoolchildren.

PubMed

Nordvall, S L; Janson, C; Kalm-Stephens, P; Foucard, T; Torén, K; Alving, K

2005-04-01

Exhaled nitric oxide (NO) reflects inflammation in the lower airways and is well adapted for use in children. The aims of this study were to investigate the distribution of the fraction of expired NO (FENO) in school children and to compare FENO and spirometry in relation to the International Study of Asthma and Allergies in Childhood questionnaire. The study was performed in 959 randomly selected 13-14-year-old school children in Uppsala, Sweden. Exhaled NO was measured at an inhalation rate of 0.1 l/s (FENO0.1) and a spirometric test was performed and data from these measurements were related to questionnaire data. Exhaled NO was measured according to American Thoracic Society recommendations, except the use of a mouth wash and an exhalation flow rate of 0.1 l/s. The distribution of the mean FENO0.1 values was skewed, with a preponderance of very low levels and a widespread tail of values ranging up to 102 parts per billion (ppb). Boys exhibited significantly higher mean FENO0.1 values than girls, 5.2 (4.7-5.7) vs 4.4 (4.0-4.8) ppb (geometric mean and 95% CI), P <0.01). Children who reported wheezing in the last year had higher FENO0.1 values than children that had not, 8.5 (7.1-10.2) vs 4.3 (4.0-4.6) ppb, P <0.001). The same association was found to most symptoms indicating hay fever and eczema. In contrast to this, only weak or inconsistent associations were found between asthma and spirometric indices. Exhaled NO levels were found to be independently related to male gender, wheeze and rhinoconjuctivitis but not to current eczema. In conclusion, exhaled NO was closely associated with reported asthma and allergy symptoms whereas spirometric indices such as percent predicted forced expiratory volume in 1 s were not. As most asthma cases in a population are mild, the findings suggest that exhaled NO is a sensitive marker of asthma and allergy.

Comparative developmental toxicity of planar polychlorinated biphenyl congeners in chickens, American kestrels, and common terns

USGS Publications Warehouse

Hoffman, D.J.; Melancon, M.J.; Klein, P.N.; Eisemann, J.D.; Spann, J.W.

1998-01-01

The effects of PCB congeners, PCB 126 (3,3',4,4',5-pentaCB) and PCB 77 (3,3'4,4'-tetraCB), were examined in chicken (Gallus gallus), American kestrel (Falco sparverius), and common tern (Sterna hirundo) embryos through hatching, following air cell injections on day 4. PCB 126 caused malformations and edema in chickens starting at 0.3 ppb, in kestrels at 2.3 ppb, but in terns only at levels affecting hatching success (44 ppb). Extent of edema was most severe in chickens and least in terns. Defects of the beak were common in all species, but with crossed beak most prevalent in terns. Effects on embryo growth were most apparent for PCB 126 in chickens and kestrels. The approximate LD50 for PCB 126 in chickens was 0.4 ppb, in kestrels was 65 ppb, and in terns was 104 ppb. The approximate LD50 for PCB 77 in chickens was 2.6 ppb and in kestrels was 316 ppb. Induction of cytochrome P450 associated monooxygenase activity (EROD activity) by PCB 126 in chick embryo liver was about 800 times more responsive than in tern and at least 1000 times more responsive than in kestrel. High concentrations of PCB 126 found in bald eagle eggs are nearly 20-fold higher than the lowest toxic concentration tested in kestrels. Concentrations of PCB 126 causing low level toxic effects in common tern eggs are comparable to highest levels in common terns and Forster's terns in the field, suggesting additional involvement of other compounds in the Great Lakes.

Light emitting diode excitation emission matrix fluorescence spectroscopy.

PubMed

Hart, Sean J; JiJi, Renée D

2002-12-01

An excitation emission matrix (EEM) fluorescence instrument has been developed using a linear array of light emitting diodes (LED). The wavelengths covered extend from the upper UV through the visible spectrum: 370-640 nm. Using an LED array to excite fluorescence emission at multiple excitation wavelengths is a low-cost alternative to an expensive high power lamp and imaging spectrograph. The LED-EEM system is a departure from other EEM spectroscopy systems in that LEDs often have broad excitation ranges which may overlap with neighboring channels. The LED array can be considered a hybrid between a spectroscopic and sensor system, as the broad LED excitation range produces a partially selective optical measurement. The instrument has been tested and characterized using fluorescent dyes: limits of detection (LOD) for 9,10-bis(phenylethynyl)-anthracene and rhodamine B were in the mid parts-per-trillion range; detection limits for the other compounds were in the low parts-per-billion range (< 5 ppb). The LED-EEMs were analyzed using parallel factor analysis (PARAFAC), which allowed the mathematical resolution of the individual contributions of the mono- and dianion fluorescein tautomers a priori. Correct identification and quantitation of six fluorescent dyes in two to six component mixtures (concentrations between 12.5 and 500 ppb) has been achieved with root mean squared errors of prediction (RMSEP) of less than 4.0 ppb for all components.

Borehole strainmeter measurements spanning the 2014, Mw6.0 South Napa Earthquake, California: The effect from instrument calibration

USGS Publications Warehouse

Langbein, John O.

2015-01-01

The 24 August 2014 Mw6.0 South Napa, California earthquake produced significant offsets on 12 borehole strainmeters in the San Francisco Bay area. These strainmeters are located between 24 and 80 km from the source and the observed offsets ranged up to 400 parts-per-billion (ppb), which exceeds their nominal precision by a factor of 100. However, the observed offsets of tidally calibrated strains differ by up to 130 ppb from predictions based on a moment tensor derived from seismic data. The large misfit can be attributed to a combination of poor instrument calibration and better modeling of the strain fit from the earthquake. Borehole strainmeters require in-situ calibration, which historically has been accomplished by comparing their measurements of Earth tides with the strain-tides predicted by a model. Although the borehole strainmeter accurately measure the deformation within the borehole, the long-wavelength strain signals from tides or other tectonic processes recorded in the borehole are modified by the presence of the borehole and the elastic properties of the grout and the instrument. Previous analyses of surface-mounted, strainmeter data and their relationship with the predicted tides suggest that tidal models could be in error by 30%. The poor fit of the borehole strainmeter data from this earthquake can be improved by simultaneously varying the components of the model tides up to 30% and making small adjustments to the point-source model of the earthquake, which reduces the RMS misfit from 130 ppb to 18 ppb. This suggests that relying on tidal models to calibrate borehole strainmeters significantly reduces their accuracy.

Granulite sulphides as tracers of lower crustal origin and evolution: An example from the Slave craton, Canada

NASA Astrophysics Data System (ADS)

Aulbach, Sonja; Krauss, Cristen; Creaser, Robert A.; Stachel, Thomas; Heaman, Larry M.; Matveev, Sergei; Chacko, Thomas

2010-09-01

We carried out a detailed study of sulphide minerals, a ubiquitous mineral group in lower crustal mafic to peraluminous granulite xenoliths from the Diavik kimberlites, to assess their use in constraining the origin and tectonothermal evolution of the deep crust, and to obtain additional data on the composition of lower crust beneath ancient continents. Sulphides are overwhelmingly pyrrhotite with minor Ni (0.7-3.9 at.%), Co (0.1-0.7 at.%), and Cu contents (0.4-3.9 at.%). Sulphide modes in mafic granulites range from 0.14 to 0.55 vol%, translating into bulk rock S contents from ˜600 to 2000 ppm, similar to S contents in other mafic igneous rocks and indicating preservation of primary igneous S contents. In mafic granulites, Re and Os abundances in sulphides range from 42.5 to 726 ppb and 3.2 to 180 ppb, respectively, whereas those in peraluminous granulites are distinctly lower (36.1-282 ppb and 1.8-7.2 ppb, respectively), suggestive of Re and Os loss to fractionating sulphides in the more evolved precursors of these rocks. The significant within-sample variability of 187Os/ 188Os and correlation with 187Re/ 188Os indicates the preservation of primary Re-Os isotope systematics and time-integrated decay of the measured 187Re. Within the large uncertainties inherent in the nature of the samples and technique, sulphides in some granulites may record major tectonothermal events in the central Slave craton spanning several billion years of evolution. Multiple generations of sulphide can occur in a single sample. These data attest to the heterogeneous composition and complex history of the Slave craton lower crust.

Drinking water: a major source of lead exposure in Karachi, Pakistan.

PubMed

Ul-Haq, N; Arain, M A; Badar, N; Rasheed, M; Haque, Z

2011-11-01

Excess lead in drinking water is a neglected source of lead toxicity in Pakistan. A cross-sectional survey in 2007/08 was made of water samples from drinking water sources in Karachi, a large industrial city. This study aimed to compare lead levels between untreated ground water and treated surface (tap) water in 18 different districts. Of 216 ground and surface water samples collected, 86% had lead levels higher than the World Health Organization maximum acceptable concentration of l0 ppb. Mean lead concentration in ground water [146 (SD 119) ppb] was significantly higher than in surface water [77.1 (SD 54) ppb]. None of the 18 districts had a mean lead level of ground or surface water below the WHO cut-off and ground water sources in 9 districts had a severe level of contamination (>150 ppb). Urgent action is needed to eliminate sources of contamination.

Chronic Exposure of Imidacloprid and Clothianidin Reduce Queen Survival, Foraging, and Nectar Storing in Colonies of Bombus impatiens

PubMed Central

Scholer, Jamison; Krischik, Vera

2014-01-01

In an 11-week greenhouse study, caged queenright colonies of Bombus impatiens Cresson, were fed treatments of 0 (0 ppb actual residue I, imidacloprid; C, clothianidin), 10 (14 I, 9 C), 20 (16 I, 17C), 50 (71 I, 39 C) and 100 (127 I, 76 C) ppb imidacloprid or clothianidin in sugar syrup (50%). These treatments overlapped the residue levels found in pollen and nectar of many crops and landscape plants, which have higher residue levels than seed-treated crops (less than 10 ppb, corn, canola and sunflower). At 6 weeks, queen mortality was significantly higher in 50 ppb and 100 ppb and by 11 weeks in 20 ppb–100 ppb neonicotinyl-treated colonies. The largest impact for both neonicotinyls starting at 20 (16 I, 17 C) ppb was the statistically significant reduction in queen survival (37% I, 56% C) ppb, worker movement, colony consumption, and colony weight compared to 0 ppb treatments. Bees at feeders flew back to the nest box so it appears that only a few workers were collecting syrup in the flight box and returning the syrup to the nest. The majority of the workers sat immobilized for weeks on the floor of the flight box without moving to fed at sugar syrup feeders. Neonicotinyl residues were lower in wax pots in the nest than in the sugar syrup that was provided. At 10 (14) ppb I and 50 (39) ppb C, fewer males were produced by the workers, but queens continued to invest in queen production which was similar among treatments. Feeding on imidacloprid and clothianidin can cause changes in behavior (reduced worker movement, consumption, wax pot production, and nectar storage) that result in detrimental effects on colonies (queen survival and colony weight). Wild bumblebees depending on foraging workers can be negatively impacted by chronic neonicotinyl exposure at 20 ppb. PMID:24643057

Quantum cascade laser-based screening portal for the detection of explosive precursors

NASA Astrophysics Data System (ADS)

Lindley, Ruth; Normand, Erwan; Howieson, Iain; McCulloch, Michael; Black, Paul; Lewis, Colin; Foulger, Brian

2007-10-01

In recent years, quantum cascade lasers (QCL) have been proven in robust, high-performance gas analyzers designed for continuous emission monitoring (CEM) in harsh environments. In 2006, Cascade Technologies reported progress towards adapting its patented technology for homeland security applications by publishing initial results on explosive compound detection. This paper presents the performance and results from a QCL-based people screening portal developed during the past year and aimed at the detection of precursors used in the make up of improvised explosive devices (IED). System tests have been carried out on a large number of potential interferents, together with target precursor materials, reinforcing original assumptions that compound fingerprinting can be effectively demonstrated using this technique. Results have shown that an extremely high degree of specificity can be achieved with a sub-second response time. Furthermore, it has been shown that unambiguous precursor signature recognition can be extended to compound mixtures associated with the intermediate stages in the make up of IEDs, whilst maintaining interferent immunity. The portal sensitivity was configured for parts per billion (ppb) detection level thresholds, but is currently being reconfigured for sub-ppb detection. In summary, the results obtained from the QCL based portal indicate that development of a low cost detection system, with enhanced features such as low false positive and high throughput screening of individuals or items, is possible. Development and testing was carried out with the support of the UK government.

Inflammatory Markers in Blood and Exhaled Air after Short-Term Exposure to Cooking Fumes

PubMed Central

Svedahl, Sindre Rabben

2013-01-01

Objectives: Cooking fumes contain aldehydes, alkanoic acids, polycyclic aromatic hydrocarbons, and heterocyclic compounds. The inhalation of cooking fumes entails a risk of deleterious health effects. The aim of this study was to see if the inhalation of cooking fumes alters the expression of inflammatory reactions in the bronchial mucosa and its subsequent systemic inflammatory response in blood biomarkers. Methods: Twenty-four healthy volunteers stayed in a model kitchen on two different occasions for 2 or 4h. On the first occasion, there was only exposure to normal air, and on the second, there was exposure to controlled levels of cooking fumes. On each occasion, samples of blood, exhaled air, and exhaled breath condensate (EBC) were taken three times in 24h and inflammatory markers were measured from all samples. Results: There was an increase in the concentration of the d-dimer in blood from 0.27 to 0.28mg ml–1 on the morning after exposure to cooking fumes compared with the levels the morning before (P-value = 0.004). There was also a trend of an increase in interleukin (IL)-6 in blood, ethane in exhaled air, and IL-1β in EBC after exposure to cooking fumes. In a sub-analysis of 12 subjects, there was also an increase in the levels of ethane—from 2.83 parts per billion (ppb) on the morning before exposure to cooking fumes to 3.53 ppb on the morning after exposure (P = 0.013)—and IL-1β—from 1.04 on the morning before exposure to cooking fumes to 1.39 pg ml–1 immediately after (P = 0.024). Conclusion: In our experimental setting, we were able to unveil only small changes in the levels of inflammatory markers in exhaled air and in blood after short-term exposure to moderate concentrations of cooking fumes. PMID:23179989

Impact of Biogenic Emission Uncertainties on the Simulated Response of Ozone and Fine Particulate Matter to Anthropogenic Emission Reductions

PubMed Central

Hogrefe, Christian; Isukapalli, Sastry S.; Tang, Xiaogang; Georgopoulos, Panos G.; He, Shan; Zalewsky, Eric E.; Hao, Winston; Ku, Jia-Yeong; Key, Tonalee; Sistla, Gopal

2011-01-01

The role of emissions of volatile organic compounds and nitric oxide from biogenic sources is becoming increasingly important in regulatory air quality modeling as levels of anthropogenic emissions continue to decrease and stricter health-based air quality standards are being adopted. However, considerable uncertainties still exist in the current estimation methodologies for biogenic emissions. The impact of these uncertainties on ozone and fine particulate matter (PM2.5) levels for the eastern United States was studied, focusing on biogenic emissions estimates from two commonly used biogenic emission models, the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the Biogenic Emissions Inventory System (BEIS). Photochemical grid modeling simulations were performed for two scenarios: one reflecting present day conditions and the other reflecting a hypothetical future year with reductions in emissions of anthropogenic oxides of nitrogen (NOx). For ozone, the use of MEGAN emissions resulted in a higher ozone response to hypothetical anthropogenic NOx emission reductions compared with BEIS. Applying the current U.S. Environmental Protection Agency guidance on regulatory air quality modeling in conjunction with typical maximum ozone concentrations, the differences in estimated future year ozone design values (DVF) stemming from differences in biogenic emissions estimates were on the order of 4 parts per billion (ppb), corresponding to approximately 5% of the daily maximum 8-hr ozone National Ambient Air Quality Standard (NAAQS) of 75 ppb. For PM2.5, the differences were 0.1–0.25 μg/m3 in the summer total organic mass component of DVFs, corresponding to approximately 1–2% of the value of the annual PM2.5 NAAQS of 15 μg/m3. Spatial variations in the ozone and PM2.5 differences also reveal that the impacts of different biogenic emission estimates on ozone and PM2.5 levels are dependent on ambient levels of anthropogenic emissions. PMID:21305893

Traffic-related air pollution: Exposure and health effects in Copenhagen street cleaners and cemetery workers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Raaschou-Nielsen, O.; Nielsen, M.L.; Gehl, J.

This questionaire-based study found a significantly higher prevalence of chronic bronchitis, asthma, and several other symptoms in 116 Copenhagen street cleaners who were exposed to traffic-related air pollution at levels that were slightly lower than the 1987 World Health Organization-recommended threshold values, compared with 115 Copenhagen cemetery workers exposed to lower pollution levels. Logistic regression analysis, controlling for age and smoking, was conducted, and odds ratios and 95% confidence intervals were calculated to be 2.5 for chronic bronchitis (95% confidence interval = 1.2-5.1), 2.3 for asthma (95% confidence interval = 1.0-5.1), and 1.8-7.9 for other symptoms (95% confidence interval =more » 1.0-28.2). Except for exposure to air pollution, the two groups were comparable, i.e., they had similar terms of employment and working conditions. the exposure ranges during an 8-h work day, averaged from readings taken at five monitored street positions, were: 41-257 ppb nitric oxide (1-h max: 865 ppb); 23-43 ppb nitrogen dioxide (1-h max: 208 ppb); 1.0-4.3 ppm carbon monoxide (8-h max: 7.1 ppm); 14-28 ppb sulfur dioxide (1-h max; 112 ppb); and 10-38 ppb ozone (1-h max: 72 ppb). 33 refs., 7 tabs.« less

Isolation and Identification of Plant Growth Promoting Rhizobacteria from Cucumber Rhizosphere and Their Effect on Plant Growth Promotion and Disease Suppression

PubMed Central

Islam, Shaikhul; Akanda, Abdul M.; Prova, Ananya; Islam, Md. T.; Hossain, Md. M.

2016-01-01

Plant growth promoting rhizobacteria (PGPR) are the rhizosphere bacteria that may be utilized to augment plant growth and suppress plant diseases. The objectives of this study were to identify and characterize PGPR indigenous to cucumber rhizosphere in Bangladesh, and to evaluate their ability to suppress Phytophthora crown rot in cucumber. A total of 66 isolates were isolated, out of which 10 (PPB1, PPB2, PPB3, PPB4, PPB5, PPB8, PPB9, PPB10, PPB11, and PPB12) were selected based on their in vitro plant growth promoting attributes and antagonism of phytopathogens. Phylogenetic analysis of 16S rRNA sequences identified these isolates as new strains of Pseudomonas stutzeri, Bacillus subtilis, Stenotrophomonas maltophilia, and Bacillus amyloliquefaciens. The selected isolates produced high levels (26.78–51.28 μg mL-1) of indole-3-acetic acid, while significant acetylene reduction activities (1.79–4.9 μmole C2H4 mg-1 protein h-1) were observed in eight isolates. Cucumber plants grown from seeds that were treated with these PGPR strains displayed significantly higher levels of germination, seedling vigour, growth, and N content in root and shoot tissue compared to non-treated control plants. All selected isolates were able to successfully colonize the cucumber roots. Moreover, treating cucumber seeds with these isolates significantly suppressed Phytophthora crown rot caused by Phytophthora capsici, and characteristic morphological alterations in P. capsici hyphae that grew toward PGPR colonies were observed. Since these PGPR inoculants exhibited multiple traits beneficial to the host plants, they may be applied in the development of new, safe, and effective seed treatments as an alternative to chemical fungicides. PMID:26869996

Evaluation of two mycotoxin binders to reduce toxicity of broiler diets containing ochratoxin A and T-2 toxin contaminated grain.

PubMed

García, A R; Avila, E; Rosiles, R; Petrone, V M

2003-01-01

In order to assess ochratoxin A (OA) and T-2 toxin (T-2) binding ability of two commercial sorbents, both in vitro and in vivo trials with broilers were performed. Crude OA and T-2 extracts from contaminated grain were used to assess in vitro binding ability of two sorbents (Zeotek [Zk] and Mycofix [Mx]), by quantifying free mycotoxin through an enzyme-linked immunosorbent assay (ELISA) test. For in vivo trial, a 3 x 2 x 2 factorial arrangement was used for this experiment, being the factors: adsorbents (none, Zk, and Mx), OA (0 and 567 parts per billion [ppb]) and T-2 (0 and 927 ppb). OA and T-2 contaminated wheat and corn, respectively, were added to sorghum-soybean meal diets to meet 567 ppb of OA and 927 ppb of T-2. Mycotoxins were fed alone or combined in treatments. After 21 days, blood chemistry, gross, and histological evaluations were performed. Relative weights of liver, kidney, and bursa of Fabricius were obtained. Zk had the highest OA and T-2 in vitro binding ability (100% and 8.67%, respectively). Chickens fed OA with or without sorbents had a lower body weight and feed intake reduction. However, those birds fed T-2 were partly protected by a sorbent. Birds fed both toxins showed toxic additive effects, and no protection of any adsorbent was observed. A significant reduction in plasma proteins, albumin, and globulins was a characteristic observed in all birds fed diets with OA both with or without adsorbents. Uric acid level in blood was increased in all chickens fed OA-contaminated diets. Histological findings observed in birds fed OA-contaminated diets were necrosis of kidney tubular cells, swollen and necrotic hepatocytes, bile ducts hyperplasia, and increased diameter of proventriculus glands. In birds that received T-2 alone, only the liver, with the same kind of lesions, was affected. According to these results, it can be concluded that there is not a relation between in vitro and in vivo trials. OA toxic effects could not be counteracted by any sorbent. T-2 toxicity could be partially counteracted by an adsorbent used in this research.

Mercury and Other Metals in Feathers of Common Eider (Somateria mollissima) and Tufted Puffin (Fratercula cirrhata) from the Aleutian Chain of Alaska

PubMed Central

Gochfeld, Michael

2014-01-01

We analyzed arsenic, cadmium, chromium, lead, manganese, mercury, and selenium in the feathers of common eiders (Somateria mollissima) and tufted puffins (Fratercula cirrhata) from Amchitka and Kiska islands (Aleutians). Between species, puffins had 10 times higher chromium (arithmetic mean = 1820 ppb), 7.5 times higher selenium (mean = 6600 ppb), and 3 times higher mercury (mean = 2540 ppb) than eiders. Eiders had significantly higher levels of manganese than puffins. Puffins are higher on the food chain than eiders, which is reflected in their generally higher levels of metals in their feathers. Interisland differences were generally small, and there were few significant differences as a function of the three nuclear test locations on Amchitka. The only sex-related difference was that female puffins had higher mercury than males (arithmetic mean of 3060 ppb vs. 2270 ppb). Mean levels of metals in the feathers of puffins and eiders from the Aleutians were low compared with comparable studies elsewhere, and the relatively low levels of metals do not indicate the potential for adverse behavioral or reproductive effects in the birds themselves, nor pose concern for other consumers, including subsistence hunters. PMID:18712499

Comparative developmental toxicity of planar polychlorinated biphenyl congeners in chickens, American kestrels, and common terns

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoffman, D.J.; Melancon, M.J.; Klein, P.N.

1998-04-01

The effects of polychlorinated biphenyl (PCB) congeners, PCB 126 (3,3{prime},4,4{prime},5-pentaCB) and PCB 77 (3,3{prime},4,4{prime}-tetraCB), were examined in chicken (Gallus gallus), American kestrel (Falco sparverius), and common tern (Sterna hirundo) embryos through hatching, following air cell injections on day 4. PCB 126 caused malformations and edema in chickens starting at 0.3 ppb, in kestrels at 2.3 to 23 ppb, but in terns only at levels affecting hatching success (44 ppb). Extent of edema was most severe in chickens and least in terns. Defects of the beak were common in all species but with crossed beak most prevalent in terns. Effects onmore » embryo growth were most apparent for PCB 126 in chickens and kestrels. The approximate 50% lethal dose (LD50) for PCB 126 in chickens was 0.4 ppb, in kestrels was 65 ppb, and in terns was 104 ppb. The approximate LD50 for PCB 77 in chickens was 2.6 ppb and in kestrels was 316 ppb. Induction of cytochrome P450 associated monooxygenase activity (ethoxyresorufin-O-dealkylase activity) by PCB 126 in chick embryo liver was about 800 times more responsive than in tern and at least 1,000 times more responsive than in kestrel. High concentrations of PCB 126 found in bald eagle eggs are nearly 20-fold higher than the lowest toxic concentration tested in kestrels. Concentrations of PCB 126 causing low-level toxic effects in common tern eggs are comparable to highest levels in common terns and Forster`s terns in the field, suggesting additional involvement of other compounds in the Great Lakes.« less

Iridium and trace element measurements from the Cretaceous-Tertiary boundary, site 752, Broken Ridge, Indian Ocean

NASA Technical Reports Server (NTRS)

Schuraytz, B. C.; O'Connell, S.; Sharpton, V. L.

1991-01-01

Fourteen samples spanning a 2.5 m interval that includes the Cretaceous-Tertiary (K/T) boundary from Hole 752B near the crest of Broken Ridge in the eastern Indian Ocean were studied in order to search for anomalous enrichments of iridium (Ir) and shock-metamorphosed quartz grains. No allogenic quartz grains larger than 10 microns were observed, hence the presence of quartz containing diagnostic evidence of shock-metamorphism could not be confirmed. Two Ir anomalies of 2.2 +/- 0.6 and 2.0 +/- 0.4 parts per billion (ppb) were measured in samples of dark green ash-bearing chalk at depths of 357.93 and 358.80 m below seafloor, respectively. These samples containing anomalous enrichments of Ir were taken from approximately 82 cm above and 5 cm below the extinction level of Globotruncanids. Our results are consistent with those of Michel et al., who observe elevated concentrations of Ir at these depths in addition to a larger Ir anomaly associated with the extinction level of Globotruncanids.

Mycotoxins – Limits and Regulations

PubMed Central

Mazumder, Papiya Mitra; Sasmal, D.

2001-01-01

Since early years, a need has always been felt for some control on the quality of foodstuffs. With the discovery of aflatoxins in the early sixties, health authorities in man countries have become active in establishing regulations to protect their citizens and livestock fro t potential harm caused by mycotoxins. FDA mycotox-ins-in-foods sampling program is continuing with an objective to remove those foods from interstate commerce that contain Aflatoxins “at levels judged to be of regulator significance” Aflatoxins, Fumonisin B1 and B2, Deoxynivalenol (DON) Ochratoxin A and Patulin occur in a number of food products. FDA workers were instructed to sample and analyze all products for different types of mycotoxins. All baby foods should always be analyzed for all type of mycotoxins. The limits of Aflatoxins B1,B2,! < G2, and M1 in foods and feed stuffs varies from (0-40) ppb for foods & 0-1000ppb for food); for Ochratoxin A(0-50 ppb in food and 0-1000ppb in feed); for Don (500-2000ppb in food & 5-10,000 ppb in feed); for Zearalenone (0-1000 ppb in food); for Patulin (0-50 ppb in foods), for Diacetoxyscirpenol (0-100 ppd in feed); for chetomin (0ppb I feed); for stachybotryotoxin (0ppb in feeds and for Fumonisins (0-1000 ppb in food 5000-50,000 ppb in feedstuffs). PMID:22557007

Performance of a new hand-held device for exhaled nitric oxide measurement in adults and children

PubMed Central

Alving, K; Janson, C; Nordvall, L

2006-01-01

Background Exhaled nitric oxide (NO) measurement has been shown to be a valuable tool in the management of patients with asthma. Up to now, most measurements have been done with stationary, chemiluminescence-based NO analysers, which are not suitable for the primary health care setting. A hand-held NO analyser which simplifies the measurement would be of value both in specialized and primary health care. In this study, the performance of a new electrochemical hand-held device for exhaled NO measurements (NIOX MINO) was compared with a standard stationary chemiluminescence unit (NIOX). Methods A total of 71 subjects (6–60 years; 36 males), both healthy controls and atopic patients with and without asthma were included. The mean of three approved exhalations (50 ml/s) in each device, and the first approved measurement in the hand-held device, were compared with regard to NO readings (Bland-Altman plots), measurement feasibility (success rate with 6 attempts) and repeatability (intrasubject SD). Results Success rate was high (≥ 84%) in both devices for both adults and children. The subjects represented a FENO range of 8–147 parts per billion (ppb). When comparing the mean of three measurements (n = 61), the median of the intrasubject difference in exhaled NO for the two devices was -1.2 ppb; thus generally the hand-held device gave slightly higher readings. The Bland-Altman plot shows that the 95% limits of agreement were -9.8 and 8.0 ppb. The intrasubject median difference between the NIOX and the first approved measurement in the NIOX MINO was -2.0 ppb, and limits of agreement were -13.2 and 10.2 ppb. The median repeatability for NIOX and NIOX MINO were 1.1 and 1.2 ppb, respectively. Conclusion The hand-held device (NIOX MINO) and the stationary system (NIOX) are in clinically acceptable agreement both when the mean of three measurements and the first approved measurement (NIOX MINO) is used. The hand-held device shows good repeatability, and it can be used successfully on adults and most children. The new hand-held device will enable the introduction of exhaled NO measurements into the primary health care. PMID:16626491

Lead (Pb) in biota and perceptions of Pb exposure at a recently designated Superfund beach site in New Jersey.

PubMed

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2012-01-01

The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did.

LEAD (Pb) IN BIOTA AND PERCEPTIONS OF Pb EXPOSURE AT A RECENTLY DESIGNATED SUPERFUND BEACH SITE IN NEW JERSEY

PubMed Central

Burger, Joanna; Gochfeld, Michael; Jeitner, Christian; Donio, Mark; Pittfield, Taryn

2014-01-01

The Raritan Bay Slag Site (New Jersey) was designated a Superfund site in 2009 because the seawall, jetties, and sediment contained lead (Pb). Our objective was to compare Pb and mercury (Hg) levels in biota and public perceptions of exposure at the Superfund and reference sites. Samples (algae, invertebrates, fish) were collected from the Raritan Bay Slag Site and reference sites and analyzed for Pb and Hg. Waterfront users were interviewed using a standard questionnaire. Levels of Pb in aquatic organisms were compared to ecological and human health safety standards. Lead levels were related to location, trophic level, and mobility. Lead levels in biota were highest at the western side of the West Jetty. Mean Pb levels were highest for algae (Fucus = 53,600 ± 6990 ng/g = ppb [wet weight], Ulva = 23,900 ± 2430 ppb), intermediate for grass shrimp (7270 ± 1300 ppb, 11,600 ± 3340 ppb), and lowest for fish (Atlantic silversides 218 ± 44 ppb). Within species, Pb levels varied significantly across the sampling sites. Lead levels in algae, sometimes ingested by individuals, were sufficiently high to exceed human safety levels. Mercury levels did not differ between the Superfund and reference sites. Despite the fence and warnings, people (1) used the Superfund and reference sites similarly, (2) had similar fish consumption rates, and (3) were not concerned about Pb, although most individuals knew the metal was present. The fish sampled posed no apparent risk for human consumers, but the algae did. PMID:22409490

Use of passive samplers to measure atmospheric ammonia levels in a high-density industrial hog farm area of eastern North Carolina

NASA Astrophysics Data System (ADS)

Wilson, Sacoby M.; Serre, Marc L.

Hog concentrated animal feeding operations (CAFOs) in North Carolina release ammonia (NH 3), hydrogen sulfide, VOCs, and particulate matter to the atmosphere. These operations are located mainly in the NC coastal plain and can create potential health hazards for nearby human populations. Limited work has been performed to measure NH 3 at the community level to assess potential human exposure. In an effort to address this issue, a study was designed to measure NH 3 levels near hog CAFOs and community locations (i.e. homes and schools) in Eastern NC. NH 3 was collected using passive diffusion tubes in triplicate exposed primarily in weekly intervals. Sampling occurred from October 2003 to May 2004 (20 sites) and from July 2004 to October 2004 (23 sites) at varying distances from hog CAFOs in close proximity to homes and schools. Average weekly NH3 levels were measured as mass (μg NH 3-N) and converted to concentration (ppb). Mean level of 13.8 ppb near homes and schools (<2 km) was 4-12 times greater than ambient background levels (1-3 ppb), reaching as high as 80 ppb. Exposed sites (<2 km from a hog CAFO) had a mean level of 12.8 ppb which was over 2 times higher than the mean level of 5.5 ppb at less exposed sites (>2 km from a hog CAFO). The study establishes that passive sampling can be effectively used to measure average atmospheric ammonia levels at community locations near hog CAFOs in Eastern NC. The collected data indicate the relative exposure for human populations who live near a hog CAFO. The closer a populace is to the hog CAFO, the more intense the exposure. These results require more validation in the field by comparison to a reference method.

Higher Levels of Aflatoxin M1 Contamination and Poorer Composition of Milk Supplied by Informal Milk Marketing Chains in Pakistan

PubMed Central

Aslam, Naveed; Tipu, Muhammad Yasin; Ishaq, Muhammad; Cowling, Ann; McGill, David; Warriach, Hassan Mahmood; Wynn, Peter

2016-01-01

The present study was conducted to observe the seasonal variation in aflatoxin M1 and nutritional quality of milk along informal marketing chains. Milk samples (485) were collected from three different chains over a period of one year. The average concentrations of aflatoxin M1 during the autumn and monsoon seasons (2.60 and 2.59 ppb) were found to be significantly higher (standard error of the difference, SED = 0.21: p = 0.003) than in the summer (1.93 ppb). The percentage of added water in milk was significantly lower (SED = 1.54: p < 0.001) in summer (18.59%) than in the monsoon season (26.39%). There was a significantly different (SED = 2.38: p < 0.001) mean percentage of water added by farmers (6.23%), small collectors (14.97%), large collectors (27.96%) and retailers (34.52%). This was reflected in changes in milk quality along the marketing chain. There was no difference (p = 0.178) in concentration of aflatoxin M1 in milk collected from the farmers (2.12 ppb), small collectors (2.23 ppb), large collectors (2.36 ppb) and retailers (2.58 ppb). The high levels of contamination found in this study, which exceed the standards set by European Union (0.05 ppb) and USFDA (0.5 ppb), demand radical intervention by regulatory authorities and mass awareness of the consequences for consumer health and safety. PMID:27929386

Short-term ozone exposure and asthma severity: Weight-of-evidence analysis.

PubMed

Goodman, Julie E; Zu, Ke; Loftus, Christine T; Lynch, Heather N; Prueitt, Robyn L; Mohar, Isaac; Shubin, Sara Pacheco; Sax, Sonja N

2018-01-01

To determine whether evidence indicates that short-term exposure to ambient concentrations of ozone in the United States can affect asthma severity, we systematically reviewed published controlled human exposure, epidemiology, and animal toxicity studies. The strongest evidence for a potential causal relationship came from epidemiology studies reporting increased emergency department visits and hospital admissions for asthma following elevated ambient ozone concentrations. However, while controlled exposure studies reported lung function decrements and increased asthma symptoms following high ozone exposures 160-400 parts per billion [ppb]), epidemiology studies evaluating similar outcomes reported less consistent results. Animal studies showed changes in pulmonary function at high ozone concentrations (> 500ppb), although there is substantial uncertainty regarding the relevance of these animal models to human asthma. Taken together, the weight of evidence indicates that there is at least an equal likelihood that either explanation is true, i.e., the strength of the evidence for a causal relationship between short-term exposure to ambient ozone concentrations and asthma severity is "equipoise and above." Copyright © 2017 Elsevier Inc. All rights reserved.

Distribution ozone concentration in Klang Valley using GIS approaches

NASA Astrophysics Data System (ADS)

Sulaiman, A.; Rahman, A. A. Ab; Maulud, K. N. Abdul; Latif, M. T.; Ahmad, F.; Wahid, M. A. Abdul; Ibrahim, M. A.; Halim, N. D. Abdul

2017-05-01

Today, ozone has become one of the main air pollutants in Malaysia. The high ozone precursor concentrations have been encouraging the ozone production. The development of the Klang Valley, Malaysia has many types of physical activities such as urban commercial, industrial area, settlement area and others, which has increased the risk of atmospheric pollution. The purpose of this paper is to determine the spatial distribution between types of land use and ozone concentration that are occurred in the year 2014. The study areas for this paper include Shah Alam, Kajang, Petaling Jaya and Port Klang. Distribution of ozone concentration will be showed via spatial analysis tools in Geographic Information Systems (GIS) approached and the types of land use will be extracted using Remote Sensing technique. The result showed 97 ppb (parts-per-billion, 10-9) and 161 ppb recorded at Port Klang and Shah Alam respectively that are mainly represented by the settlement area. Therefore, the physical land use need to be monitor and controlled by the government in order to make sure the ozone production for daily per hour will not exceed the regulation allowed.

Effects of chromium nanoparticle dosage on growth, body composition, serum hormones and tissue chromium in Sprague-Dawley rats*

PubMed Central

Zha, Long-ying; Xu, Zi-rong; Wang, Min-qi; Gu, Liang-ying

2007-01-01

This 6-week study was conducted to evaluate the effects of seven different levels of dietary chromium (Cr) (0, 75, 150, 300, 450, 600, and 1 200 ppb Cr) in the form of Cr nanoparticle (CrNano) on growth, body composition, serum hormones and tissue Cr in Sprague-Dawley (SD) rats. Seventy male SD rats (average initial body weight of (83.2±4.4) g) were randomly assigned to seven dietary treatments (n=10). At the end of the trial, body composition was assessed via dual energy X-ray absorptiometry (DEXA). All rats were then sacrificed to collect samples of blood, organs and tissues for determination of serum hormones and tissue Cr contents. The results indicated that lean body mass was significantly increased (P<0.05) due to the addition of 300 and 450 ppb Cr from CrNano. Supplementation of 150, 300, 450, and 600 ppb Cr decreased (P<0.05) percent body fat significantly. Average daily gain was increased (P<0.05) by addition of 75, 150, and 300 ppb Cr and feed efficiency was increased (P<0.05) by supplementation of 75, 300, and 450 ppb Cr. Addition of 300 and 450 ppb Cr decreased (P<0.05) the insulin level in serum greatly. Cr contents in liver and kidney were greatly increased (P<0.05) by the addition of Cr as CrNano in the dosage of from 150 ppb to 1 200 ppb. In addition, Supplementation of 300, 450, and 600 ppb Cr significantly increased (P<0.05) Cr content in the hind leg muscle. These results suggest that supplemental CrNano has beneficial effects on growth performance and body composition, and increases tissue Cr concentration in selected muscles. PMID:17542060

Regulatory Impact Analysis of the Final Revisions to the National Ambient Air Quality Standards for Ground-Level Ozone

EPA Pesticide Factsheets

The EPA performed an illustrative analysis of the potential costs, human health benefits, and welfare benefits of nationally attaining a revised primary ozone standard of 70 ppb and a primary alternative ozone standard level of 65 ppb.

Acoustic resonance in MEMS scale cylindrical tubes with side branches

NASA Astrophysics Data System (ADS)

Schill, John F.; Holthoff, Ellen L.; Pellegrino, Paul M.; Marcus, Logan S.

2014-05-01

Photoacoustic spectroscopy (PAS) is a useful monitoring technique that is well suited for trace gas detection. This method routinely exhibits detection limits at the parts-per-million (ppm) or parts-per-billion (ppb) level for gaseous samples. PAS also possesses favorable detection characteristics when the system dimensions are scaled to a microelectromechanical system (MEMS) design. One of the central issues related to sensor miniaturization is optimization of the photoacoustic cell geometry, especially in relationship to high acoustical amplification and reduced system noise. Previous work relied on a multiphysics approach to analyze the resonance structures of the MEMS scale photo acoustic cell. This technique was unable to provide an accurate model of the acoustic structure. In this paper we describe a method that relies on techniques developed from musical instrument theory and electronic transmission line matrix methods to describe cylindrical acoustic resonant cells with side branches of various configurations. Experimental results are presented that demonstrate the ease and accuracy of this method. All experimental results were within 2% of those predicted by this theory.

Detection biomarkers of lung cancer using mini-GC-PID system integrated with micro GC column and micro pre-concentrator

PubMed Central

2014-01-01

The survival rate of lung cancer can be significantly improved by monitoring biomarkers in exhaled air that indicate diseases in early stage, so it is very important to develop micro analytical systems which can offer a fast, on-site, real-time detecting biomarkers in exhaled air. In this paper, a mini-gas chromatography (GC)-photo-ionization detector (PID) system integrated with a micro GC column and a micro pre-concentrator was developed for forming an inexpensive, fast, and non-invasive diagnostic tool for lung cancer. This system has very strong concentrate ability owing to its integrated micro pre-concentrator, which make the detection of trace components in exhaled air very easy. In addition, the integrated micro GC column can separate complex mixtures, which overcome low resolution and poor anti-interference ability of other instruments. The results indicated that the mini-GC-PID system can effectively separate and detect the biomarkers at parts-per-billion (ppb) level. PMID:25339856

Rapid determination of organochlorine pesticides and polychlorinated biphenyls, using selected ion monitoring mass spectrometry

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hargesheimer, E.E.

Methane chemical ionization (CI)-selected ion monitoring (SIM) mass spectrometry was used to identify and conclusively distinguish 19 organochlorine pesticides from polychlorinated biphenyls (PCBs) at parts-per-trillion to parts-per-billion levels in environmental water sample extracts with minimal sample cleanup. Two CI-SIM screens were developed. One set of ions scanned specifically for the presence of 4 classes of pesticides; diphenylmethane derivatives, bridged polycyclic chlorinated benzenes, and acetanilide pesticides. The second set of ions responded exclusively to PCBs with biphenyl moieties containing from 1 to 8 chlorine atoms. Eight commercial Aroclor mixtures were analyzed and distinguished from the pesticides groups. The detection limit formore » pesticides and PCBs by CI-SIM screening was 0.005 and 0.1 ppB, respectively. CI-SIM can be used as an alternative method for the analysis of biological or environmental samples containing interferences that complicate the detection of PCBs and chlorinated pesticides. 8 references, 6 figures, 6 tables.« less

Nitric oxide contamination of hospital compressed air improves gas exchange in patients with acute lung injury.

PubMed

Tan, P Seow Koon; Genc, F; Delgado, E; Kellum, J A; Pinsky, M R

2002-08-01

We tested the hypothesis that NO contamination of hospital compressed air also improves PaO(2) in patients with acute lung injury (ALI) and following lung transplant (LTx). Prospective clinical study. Cardiothoracic intensive care unit. Subjects following cardiac surgery (CABG, n=7); with ALI (n=7), and following LTx (n=5). Four sequential 15-min steps at a constant FiO(2) were used: hospital compressed air-O(2) (H1), N(2)-O(2) (A1), repeat compressed air-O(2) (H2), and repeat N(2)-O(2) (A2). NO levels were measured from the endotracheal tube. Cardiorespiratory values included PaO(2) were measured at the end of each step. FiO(2) was 0.46+/-0.05, 0.53+/-0.15, and 0.47+/-0.06 (mean+/-SD) for three groups, respectively. Inhaled NO levels during H1 varied among subjects (30-550 ppb, 27-300 ppb, and 5-220 ppb, respectively). Exhaled NO levels were not detected in 4/7 of CABG (0-300 ppb), 3/6 of ALI (0-140 ppb), and 3/5 of LTx (0-59 ppb) patients during H1, whereas during A1 all but one patient in ALI and three CABG patients had measurable exhaled NO levels (P<0.05). Small but significant decreases in PaO(2) occurred for all groups from H1 to A1 and H2 to A2 (132-99 Torr and 128-120 Torr, P <0.01, respectively). There was no correlation between inhaled NO during H1 and exhaled NO during A1 or the change in PaO(2) from H1 to A1. Low-level NO contamination improves PaO(2) in patients with ALI and following LTx.

The State of Ambient Air Quality of a Mega City in Southeast Asia (Karachi, Pakistan)

NASA Astrophysics Data System (ADS)

Khwaja, H. A.; Hussain, M. M.; Naqvi, I.; Malik, A.; Siddiqui, S. A.; Khan, A.

2016-12-01

Outdoor air pollution is a serious public health problem. Studies indicate that in recent years exposure levels have increased considerably in some parts of the world, particularly in developing countries of Asia with large populations. Simultaneous measurements of PM2.5 and gaseous pollutants NO, NO2 , SO2 , O3 , HONO, HNO3, HF, and HCl were carried out in the city of Karachi. This is the first systematic study of this kind carried out in a mega city of Pakistan. Mean concentration of PM2.5 was 186 µg/m3. Concentrations of NO, NO2 , SO2 , O3 , HONO , HNO3, HF, and HCl varied from 8.6 - 194 ppb, 15.7 - 131 ppb, 7.9 - 60 ppb, 5.0 - 218 ppb, 0.05 - 6.6 ppb, 0.1 - 10.8 ppb, 0.1 - 2.8 ppb, and 0.3 - 568 ppb, respectively. Daily patterns were observed. The 24 h mean PM2.5 on weekdays was significantly higher than the weekend value, indicating that vehicular pollution is one of the important source of PM2.5. The diurnal variations of both NO and NO2 showed higher concentrations during morning and evening rush-hours and lower concentrations at night, indicating that vehicular traffic is the principal source of NOx . Peak HONO concentration of 6.6 ppb was observed in the morning hours. The highest SO2 , HNO3 , HF, and HCl values occurred during the daytime when general pollution levels, particularly those of suspended particulate matter, were also high. Concentrations of O3 are observed to increase during the daytime, consistent with its formation by photochemical reactions. The present findings are compared with similar measurements worldwide. Results have demonstrated that WHO air quality standard for PM2.5 (20 µg/m3) were exceeded by a factor of 5 - 13. Concentrations of NO2 , SO2 and O3 were found to be significantly higher than the WHO air quality guidelines. The reported high levels were attributed to vehicular traffic and industrial activity. It has been concluded that air pollution levels in Karachi are extremely high and can be considered an alarming indicator of adverse health effects for city dwellers.

Elevated ground-level O(3) changes the diversity of anoxygenic purple phototrophic bacteria in paddy field.

PubMed

Feng, Youzhi; Lin, Xiangui; Yu, Yongchang; Zhu, Jianguo

2011-11-01

The knowledge of the impact of elevated ground-level O(3) below ground the agro-ecosystem is limited. A field experiment in China Ozone Free-Air Concentration Enrichment (FACE-O(3)) facility on a rice-wheat rotation system was carried out to investigate responses of anoxygenic phototrophic purple bacteria (AnPPB) to elevated ground-level O(3). AnPPB community structures and sizes in paddy soil were monitored by molecular approaches including PCR-DGGE and real-time quantitative PCR based upon the pufM gene on three typical rice growth stages. Repetitive sequence-based PCR (rep-PCR) in combination with culture-reliant method was conducted to reveal changes in genotypic diversity. Elevated ground-level O(3) statistically reduce AnPPB abundance and percentage in total bacterial community in flooded rice soil via decreasing their genotypic diversity and metabolic versatility. Concomitantly, their community composition changed after rice anthesis stage under elevated ground-level O(3). Our results from AnPPB potential responses imply that continuously elevated ground-level O(3) in the future would eventually harm the health of paddy ecosystem through negative effect on soil microorganisms.

Use of North American and European Air Quality Networks to Evaluate Global Chemistry-Climate Modeling of Surface Ozone

NASA Technical Reports Server (NTRS)

Schnell, J. L.; Prather, M. J.; Josse, B.; Naik, V.; Horowitz, L. W.; Cameron-Smith, P.; Bergmann, D.; Zeng, G.; Plummer, D. A.; Sudo, K.;

Detection of volatile compounds emitted by Pseudomonas aeruginosa using selected ion flow tube mass spectrometry.

PubMed

Carroll, Will; Lenney, Warren; Wang, Tianshu; Spanel, Patrik; Alcock, Alice; Smith, David

2005-05-01

Pseudomonas aeruginosa (PA) is associated with a distinctive smell produced by a combination of volatile compounds (VCs). Selected ion flow tube mass spectrometry (SIFT-MS) provides a novel and rapid methodology for rapid, accurate detection of trace quantities (parts per billion; ppb) of VCs in air. We studied the VCs produced by different isolates of PA cultures in vitro from patients with cystic fibrosis. Twenty-one patients with cystic fibrosis provided sputum and cough swab samples for culture. These were used to inoculate blood agar (BA) and Pseudomonas-selective media (PSM). These plates were incubated for 48 hr at 37 degrees C inside sealed plastic bags. The air surrounding the samples after 48 hr (headspace) was analyzed using SIFT-MS. PA growth was commonly associated with the production of significant quantities of VCs, notably hydrogen cyanide gas (HCN). This was detectable in the headspace of 15/22 of PA-positive samples. In contrast, it was only seen in the headspace of 1/13 control samples (6 sterile plates and 7 plates with only mixed upper respiratory tract flora). The concentration of HCN was significantly higher above PA-positive samples than above other bacterial growth (P < 0.01), and in our study, levels of HCN greater than 100 ppb were a sensitive (68%) and highly specific (100%) biomarker of PA. SIFT-MS can detect a range of VCs from PA in vitro. HCN may be a specific indicator of PA infection in vivo, and offers promise as a biomarker for noninvasive detection of PA infection by breath analysis. Copyright 2005 Wiley-Liss, Inc

Air Pollution and Mortality in the Medicare Population.

PubMed

Di, Qian; Wang, Yan; Zanobetti, Antonella; Wang, Yun; Koutrakis, Petros; Choirat, Christine; Dominici, Francesca; Schwartz, Joel D

2017-06-29

Studies have shown that long-term exposure to air pollution increases mortality. However, evidence is limited for air-pollution levels below the most recent National Ambient Air Quality Standards. Previous studies involved predominantly urban populations and did not have the statistical power to estimate the health effects in underrepresented groups. We constructed an open cohort of all Medicare beneficiaries (60,925,443 persons) in the continental United States from the years 2000 through 2012, with 460,310,521 person-years of follow-up. Annual averages of fine particulate matter (particles with a mass median aerodynamic diameter of less than 2.5 μm [PM 2.5 ]) and ozone were estimated according to the ZIP Code of residence for each enrollee with the use of previously validated prediction models. We estimated the risk of death associated with exposure to increases of 10 μg per cubic meter for PM 2.5 and 10 parts per billion (ppb) for ozone using a two-pollutant Cox proportional-hazards model that controlled for demographic characteristics, Medicaid eligibility, and area-level covariates. Increases of 10 μg per cubic meter in PM 2.5 and of 10 ppb in ozone were associated with increases in all-cause mortality of 7.3% (95% confidence interval [CI], 7.1 to 7.5) and 1.1% (95% CI, 1.0 to 1.2), respectively. When the analysis was restricted to person-years with exposure to PM 2.5 of less than 12 μg per cubic meter and ozone of less than 50 ppb, the same increases in PM 2.5 and ozone were associated with increases in the risk of death of 13.6% (95% CI, 13.1 to 14.1) and 1.0% (95% CI, 0.9 to 1.1), respectively. For PM 2.5 , the risk of death among men, blacks, and people with Medicaid eligibility was higher than that in the rest of the population. In the entire Medicare population, there was significant evidence of adverse effects related to exposure to PM 2.5 and ozone at concentrations below current national standards. This effect was most pronounced among self-identified racial minorities and people with low income. (Supported by the Health Effects Institute and others.).

High-Density, High-Resolution, Low-Cost Air Quality Sensor Networks for Urban Air Monitoring

NASA Astrophysics Data System (ADS)

Mead, M. I.; Popoola, O. A.; Stewart, G.; Bright, V.; Kaye, P.; Saffell, J.

2012-12-01

Monitoring air quality in highly granular environments such as urban areas which are spatially heterogeneous with variable emission sources, measurements need to be made at appropriate spatial and temporal scales. Current routine air quality monitoring networks generally are either composed of sparse expensive installations (incorporating e.g. chemiluminescence instruments) or higher density low time resolution systems (e.g. NO2 diffusion tubes). Either approach may not accurately capture important effects such as pollutant "hot spots" or adequately capture spatial (or temporal) variability. As a result, analysis based on data from traditional low spatial resolution networks, such as personal exposure, may be inaccurate. In this paper we present details of a sophisticated, low-cost, multi species (gas phase, speciated PM, meteorology) air quality measurement network methodology incorporating GPS and GPRS which has been developed for high resolution air quality measurements in urban areas. Sensor networks developed in the Centre for Atmospheric Science (University of Cambridge) incorporated electrochemical gas sensors configured for use in urban air quality studies operating at parts-per-billion (ppb) levels. It has been demonstrated that these sensors can be used to measure key air quality gases such as CO, NO and NO2 at the low ppb mixing ratios present in the urban environment (estimated detection limits <4ppb for CO and NO and <1ppb for NO2. Mead et al (submitted Aug., 2012)). Based on this work, a state of the art multi species instrument package for deployment in scalable sensor networks has been developed which has general applicability. This is currently being employed as part of a major 3 year UK program at London Heathrow airport (the Sensor Networks for Air Quality (SNAQ) Heathrow project). The main project outcome is the creation of a calibrated, high spatial and temporal resolution data set for O3, NO, NO2, SO2, CO, CO2, VOCstotal, size-speciated PM, temperature, relative humidity, wind speed and direction. The network incorporates existing GPRS infrastructures for real time sending of data with low overheads in terms of cost, effort and installation. In this paper we present data from the SNAQ Heathrow project as well as previous deployments showing measurement capability at the ppb level for NO, NO2 and CO. We show that variability can be observed and measured quantitatively using these sensor networks over widely differing time scales from individual emission events, diurnal variability associated with traffic and meteorological conditions, through to longer term synoptic weather conditions and seasonal behaviour. This work demonstrates a widely applicable generic capability to urban areas, airports as well as other complex emissions environments making this sensor system methodology valuable for scientific, policy and regulatory issues. We conclude that the low-cost high-density network philosophy has the potential to provide a more complete assessment of the high-granularity air quality structure generally observed in the environment. Further, when appropriately deployed, has the potential to offer a new paradigm in air quality quantification and monitoring.

First simultaneous measurements of peroxyacetyl nitrate (PAN) and ozone at Nam Co in the central Tibetan Plateau: impacts from the PBL evolution and transport processes

NASA Astrophysics Data System (ADS)

Xu, Xiaobin; Zhang, Hualong; Lin, Weili; Wang, Ying; Xu, Wanyun; Jia, Shihui

2018-04-01

Both peroxyacetyl nitrate (PAN) and ozone (O3) are key photochemical products in the atmosphere. Most of the previous in situ observations of both gases have been made in polluted regions and at low-altitude sites. Here we present the first simultaneous measurements of PAN and O3 at Nam Co (NMC; 30°46' N, 90°57' E, 4745 m a.s.l.), a remote site in the central Tibetan Plateau (TP). The observations were made during summer periods in 2011 and 2012. The PAN levels averaged 0.36 ppb (range: 0.11-0.76 ppb) and 0.44 ppb (range: 0.21-0.99 ppb) during 17-24 August 2011 and 15 May to 13 July 2012, respectively. The O3 level varied from 27.9 to 96.4 ppb, with an average of 60.0 ppb. Profound diurnal cycles of PAN and O3 were observed with minimum values around 05:00 LT, steep rises in the early morning, and broader platforms of high values during 09:00-20:00 LT. The evolution of the planetary boundary layer (PBL) played a key role in shaping the diurnal patterns of both gases, particularly the rapid increases of PAN and O3 in the early morning. Air entrainment from the free troposphere into the PBL seemed to cause the early-morning increase and be a key factor for sustaining the daytime high concentrations of both gases. The days with higher daytime PBL (about 3 km) showed stronger diurnal variations in both gases and were mainly distributed in the drier pre-monsoon period, while those with shallower daytime PBL (about 2 km) showed minor diurnal variations and were mainly distributed in the humid monsoon period. Episodes of higher PAN levels were occasionally observed at NMC. These PAN episodes were caused either by rapid downward transport of air masses from the middle/upper troposphere or by long-range transport of PAN plumes from north India, north Pakistan, and Nepal. The maximum PAN level in the downward transport cases ranged from 0.5 to 0.7 ppb. In the long-range transport case, the PAN level varied in the range of 0.3-1.0 ppb, with an average of 0.6 ppb. This long-range transport process influenced most of the western and central TP region for about a week in early June 2012. Our results suggest that polluted air masses from South Asia can significantly enhance the PAN level over the TP. As PAN acts as a reservoir of NOx, the impacts of pollution transport from South Asia on tropospheric photochemistry over the TP region deserve further studies.

Validation of the BetaStar® Advanced for Beta-lactams Test Kit for the Screening of Bulk Tank and Tanker Truck Milks for the Presence of Beta-lactam Drug Residues.

PubMed

Denhartigh, Andrew; Reynolds, Lindsay; Palmer, Katherine; Klein, Frank; Rice, Jennifer; Rejman, John J

2018-05-18

A validation study was conducted for an immunochromatographic method (BetaStar ® Advanced for Beta-lactams) for the detection of beta-lactam residues in raw, commingled bovine milk. The assay detected amoxicillin, ampicillin, cloxacillin, penicillin, cephapirin, and ceftiofur below the U.S. Food and Drug Administration tolerance levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. The results of internal and independent laboratory dose-response studies employing spiked samples were in agreement. The test detected all six drugs at the approximate 90/95% sensitivity levels in milk from cows treated with each drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing 1148 control milk samples. Testing the estimated 90/95% sensitivity level for amoxicillin (8.5 ppb), ampicillin (6.9 ppb), cloxacillin (8.9 ppb), penicillin (4.2 ppb), and cephapirin (17.6 ppb), and at 100 ppb for each antibiotic, resulted in 94-100% positive tests for each of the beta-lactam drugs. The results of ruggedness experiments established the operating parameter tolerances for the assay. Cross-reactivity testing established that the assay detects other certain beta-lactam drugs, but it does not cross-react with any of 30 drugs belonging to seven different drug classes. Abnormally high bacterial or somatic cell counts in raw milk produced no assay interference.

Ultra-trace level analysis of morpholine, cyclohexylamine, and diethylaminoethanol in steam condensate by gas chromatography with multi-mode inlet, and flame ionization detection.

PubMed

Luong, J; Shellie, R A; Cortes, H; Gras, R; Hayward, T

2012-03-16

Steam condensate water treatment is a vital and integral part of the overall cooling water treatment process. Steam condensate often contains varying levels of carbon dioxide and oxygen which acts as an oxidizer. Carbon dioxide forms corrosive carbonic acid when dissolved in condensed steam. To neutralize the harmful effect of the carbonic acid, volatile amine compounds such as morpholine, cyclohexylamine, and diethylaminoethanol are often employed as part of a strategy to control corrosion in the water treatment process. Due to the high stability of these compounds in a water matrix, the indirect addition of such chemicals into the process via steam condensate often results in their presence throughout the process and even into the final product. It is therefore important to understand the impact of these chemicals and their fate within a chemical plant. The ability to analyze such compounds by gas chromatography has historically been difficult due to the lack of chromatographic system inertness at the trace level concentrations especially in an aqueous matrix. Here a highly sensitive, practical, and reliable gas chromatographic approach is described for the determination of morpholine, cyclohexylamine, and diethylaminoethanol in steam condensate at the part-per-billion (ppb) levels. The approach does not require any sample enrichment or derivatization. The technique employs a multi-mode inlet operating in pulsed splitless mode with programmed inlet temperature for sample introduction, an inert base-deactivated capillary column for solute separation and flame ionization detection. Chromatographic performance was further enhanced by the incorporation of 2-propanol as a co-solvent. Detection limits for morpholine, cyclohexylamine, diethylaminoethanol were established to be 100 ppb (v/v), with relative standard deviations (RSD) of less than 6% at the 95% confidence level (n=20) and a percent recovery of 96% or higher for the solutes of interest over a range of 0.1-100 ppm (v/v). A complete analysis can be conducted in less than 10 min. Copyright © 2012 Elsevier B.V. All rights reserved.

Health benefits from large-scale ozone reduction in the United States.

PubMed

Berman, Jesse D; Fann, Neal; Hollingsworth, John W; Pinkerton, Kent E; Rom, William N; Szema, Anthony M; Breysse, Patrick N; White, Ronald H; Curriero, Frank C

2012-10-01

Exposure to ozone has been associated with adverse health effects, including premature mortality and cardiopulmonary and respiratory morbidity. In 2008, the U.S. Environmental Protection Agency (EPA) lowered the primary (health-based) National Ambient Air Quality Standard (NAAQS) for ozone to 75 ppb, expressed as the fourth-highest daily maximum 8-hr average over a 24-hr period. Based on recent monitoring data, U.S. ozone levels still exceed this standard in numerous locations, resulting in avoidable adverse health consequences. We sought to quantify the potential human health benefits from achieving the current primary NAAQS standard of 75 ppb and two alternative standard levels, 70 and 60 ppb, which represent the range recommended by the U.S. EPA Clean Air Scientific Advisory Committee (CASAC). We applied health impact assessment methodology to estimate numbers of deaths and other adverse health outcomes that would have been avoided during 2005, 2006, and 2007 if the current (or lower) NAAQS ozone standards had been met. Estimated reductions in ozone concentrations were interpolated according to geographic area and year, and concentration-response functions were obtained or derived from the epidemiological literature. We estimated that annual numbers of avoided ozone-related premature deaths would have ranged from 1,410 to 2,480 at 75 ppb to 2,450 to 4,130 at 70 ppb, and 5,210 to 7,990 at 60 ppb. Acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually if the current 75-ppb standard had been attained. Substantially greater health benefits would have resulted if the CASAC-recommended range of standards (70-60 ppb) had been met. Attaining a more stringent primary ozone standard would significantly reduce ozone-related premature mortality and morbidity.

Health Benefits from Large-Scale Ozone Reduction in the United States

PubMed Central

Berman, Jesse D.; Fann, Neal; Hollingsworth, John W.; Pinkerton, Kent E.; Rom, William N.; Szema, Anthony M.; Breysse, Patrick N.; White, Ronald H.

2012-01-01

Background: Exposure to ozone has been associated with adverse health effects, including premature mortality and cardiopulmonary and respiratory morbidity. In 2008, the U.S. Environmental Protection Agency (EPA) lowered the primary (health-based) National Ambient Air Quality Standard (NAAQS) for ozone to 75 ppb, expressed as the fourth-highest daily maximum 8-hr average over a 24-hr period. Based on recent monitoring data, U.S. ozone levels still exceed this standard in numerous locations, resulting in avoidable adverse health consequences. Objectives: We sought to quantify the potential human health benefits from achieving the current primary NAAQS standard of 75 ppb and two alternative standard levels, 70 and 60 ppb, which represent the range recommended by the U.S. EPA Clean Air Scientific Advisory Committee (CASAC). Methods: We applied health impact assessment methodology to estimate numbers of deaths and other adverse health outcomes that would have been avoided during 2005, 2006, and 2007 if the current (or lower) NAAQS ozone standards had been met. Estimated reductions in ozone concentrations were interpolated according to geographic area and year, and concentration–response functions were obtained or derived from the epidemiological literature. Results: We estimated that annual numbers of avoided ozone-related premature deaths would have ranged from 1,410 to 2,480 at 75 ppb to 2,450 to 4,130 at 70 ppb, and 5,210 to 7,990 at 60 ppb. Acute respiratory symptoms would have been reduced by 3 million cases and school-loss days by 1 million cases annually if the current 75-ppb standard had been attained. Substantially greater health benefits would have resulted if the CASAC-recommended range of standards (70–60 ppb) had been met. Conclusions: Attaining a more stringent primary ozone standard would significantly reduce ozone-related premature mortality and morbidity. PMID:22809899

Comparison of two exhaled nitric oxide analyzers: the NIOX MINO hand-held electrochemical analyzer and the NOA280i stationary chemiluminescence analyzer.

PubMed

Kim, Sang-Heon; Moon, Ji-Yong; Kwak, Hyun Jung; Kim, Sa Il; Park, Dong Won; Kim, Jee Woo; Kim, Tae Hyung; Sohn, Jang Won; Shin, Dong Ho; Park, Sung Soo; Yoon, Ho Joo

2012-07-01

Measurement of the fraction of nitric oxide (FeNO) in exhaled air is useful in the management of asthma. A new hand-held nitric oxide (NO) analyzer, the NIOX MINO, is simple and easy to use in clinical practice. In this study, FeNO values measured using the NIOX MINO were compared with those obtained using a stationary chemiluminescence analyzer, the Sievers NOA280i. FeNO was measured in 100 adults, using both the NIOX MINO and the NOA280i. Nine (9.0%) of these subjects had asthma. The first acceptable measurement with the NIOX MINO and the mean of two acceptable measurements with the NOA280i were compared. There was a significant correlation between FeNO concentrations measured with the two devices (r = 0.876, P < 0.001). A Bland-Altman plot showed a high degree of agreement between the two devices: the mean inter-device difference was 3.3 parts per billion (ppb), and the 95% limits of agreement were -7.0 and 13.6 ppb. In addition, the mean relative difference was 14.5%, with the 95% limits of agreement being -33.7 and 62.7%. The mean value (± standard error of the mean) for FeNO as measured with the NIOX MINO (18.8 ± 0.9 ppb) was significantly lower than that measured with the NOA280i (22.1 ± 1.2 ppb, P < 0.001). There was a significant correlation, but only moderate agreement, between FeNO values measured with the NIOX MINO and those measured with the NOA280i, with the NIOX MINO values being significantly lower than the NOA280i values. Significant differences in FeNO values obtained with these two NO analyzers should be considered when interpreting the results of FeNO measurements. © 2012 The Authors. Respirology © 2012 Asian Pacific Society of Respirology.

Deciphering the role of radical precursors during the Second Texas Air Quality Study.

PubMed

Olaguer, Eduardo P; Rappenglück, Bernhard; Lefer, Barry; Stutz, Jochen; Dibb, Jack; Griffin, Robert; Brune, William H; Shauck, Maxwell; Buhr, Martin; Jeffries, Harvey; Vizuete, William; Pinto, Joseph P

2009-11-01

The Texas Environmental Research Consortium (TERC) funded significant components of the Second Texas Air Quality Study (TexAQS II), including the TexAQS II Radical and Aerosol Measurement Project (TRAMP) and instrumented flights by a Piper Aztec aircraft. These experiments called attention to the role of short-lived radical sources such as formaldehyde (HCHO) and nitrous acid (HONO) in increasing ozone productivity. TRAMP instruments recorded daytime HCHO pulses as large as 32 parts per billion (ppb) originating from upwind industrial activities in the Houston Ship Channel, where in situ surface monitors detected HCHO peaks as large as 52 ppb. Moreover, Ship Channel petrochemical flares were observed to produce plumes of apparent primary HCHO. In one such combustion plume that was depleted of ozone by large emissions of oxides of nitrogen (NOx), the Piper Aztec measured a ratio of HCHO to carbon monoxide (CO) 3 times that of mobile sources. HCHO from uncounted primary sources or ozonolysis of underestimated olefin emissions could significantly increase ozone productivity in Houston beyond previous expectations. Simulations with the CAMx model show that additional emissions of HCHO from industrial flares or mobile sources can increase peak ozone in Houston by up to 30 ppb. Other findings from TexAQS II include significant concentrations of HONO throughout the day, well in excess of current air quality model predictions, with large nocturnal vertical gradients indicating a surface or near-surface source of HONO, and large concentrations of nighttime radicals (approximately30 parts per trillion [ppt] HO2). HONO may be formed heterogeneously on urban canopy or particulate matter surfaces and may be enhanced by organic aerosol of industrial or motor vehicular origin, such as through conversion of nitric acid (HNO3). Additional HONO sources may increase daytime ozone by more than 10 ppb. Improving the representation of primary and secondary HCHO and HONO in air quality models could enhance the simulated effectiveness of control strategies.

Tropospheric and lower stratospheric vertical profiles of ethane and acetylene

NASA Technical Reports Server (NTRS)

Cronn, D.; Robinson, E.

1979-01-01

The first known vertical distributions of ethane and acetylene which extend into the lower stratosphere are reported. The average upper tropospheric concentrations, between 20,000 ft and 35,000 ft, near 37 deg N-123 deg W were 1.2 micrograms/cu m (1.0 ppb) for ethane and 0.24 micrograms /cu m (0.23 ppb) for acetylene while the values near 9 N-80 W were 0.95 micrograms/cu m (0.77 ppb) and 0.09 micrograms/cu m (0.09 ppb), respectively. Detectable quantities of both ethane and acetylene are present in the lower stratosphere. There is a sharp decrease in the levels of these two compounds as one crosses the tropopause and ascends into the lower stratosphere. The observed levels of ethane and acetylene may allow some impact on the background chemistry of the troposphere and stratosphere.

Modern Material Analysis Instruments Add a New Dimension to Materials Characterization and Failure Analysis

NASA Technical Reports Server (NTRS)

Panda, Binayak

2009-01-01

Modern analytical tools can yield invaluable results during materials characterization and failure analysis. Scanning electron microscopes (SEMs) provide significant analytical capabilities, including angstrom-level resolution. These systems can be equipped with a silicon drift detector (SDD) for very fast yet precise analytical mapping of phases, as well as electron back-scattered diffraction (EBSD) units to map grain orientations, chambers that admit large samples, variable pressure for wet samples, and quantitative analysis software to examine phases. Advanced solid-state electronics have also improved surface and bulk analysis instruments: Secondary ion mass spectroscopy (SIMS) can quantitatively determine and map light elements such as hydrogen, lithium, and boron - with their isotopes. Its high sensitivity detects impurities at parts per billion (ppb) levels. X-ray photo-electron spectroscopy (XPS) can determine oxidation states of elements, as well as identifying polymers and measuring film thicknesses on coated composites. This technique is also known as electron spectroscopy for chemical analysis (ESCA). Scanning Auger electron spectroscopy (SAM) combines surface sensitivity, spatial lateral resolution (10 nm), and depth profiling capabilities to describe elemental compositions of near and below surface regions down to the chemical state of an atom.

A Summary of Ambient Air at John F. Kennedy Space Center with a Comparison to Data from the Florida Statewide Monitoring Network (1983-1992)

NASA Technical Reports Server (NTRS)

Drese, John H.

1997-01-01

The EPA criteria air pollutants were monitored at Kennedy Space Center (KSC) since 1983 to comply the prevention of significant deterioration requirements under the Clean Air Act amendments passed by Congress in 1977 and 1990. Monitoring results show that monthly maximum 24-hour total suspended particulates decreased from 144.6 micograms/cu m in 1988 to 73.0 micrograms/cu m in 1991 and increased to 149.3 micrograms/cu m in 1992. Inhalable particulates increased from 56.1 gg/M3 in 1983 to 131.4 micrograms/cu m in 1988, and then decreased to 38.5 micrograms/cu m in 1992. Sulfur dioxide monthly maximum 24-hour average concentrations decreased each year from 135.2 micrograms/cu m in 1983 to 33.8 micrograms/cu m in 1992. Nitrogen dioxide concentrations increased from 5.1 micrograms/cu m in 1983 to 5.9 micrograms/cu m in 1988, then decreased to 4.5 micrograms/cu m in 1992. Carbon monoxide annual average concentrations decreased from 6.2 micrograms/cu m in 1983 to 1.1 micrograms/cu m in 1988, and increased to 1.2 micrograms/cu m in 1992. Ozone maximum 1-hour concentrations increased from 98 parts per billion (ppb) in 1983 to 134 ppb in 1989, and then decreased to 80 ppb in 1992. Total annual rainfall ranged from 37.47 inches to 57.47 inches and shows a 6.6 percent increase over this same ten year period.

Effect of non-surgical periodontal therapy on the concentration of volatile sulfur compound in mouth air of a group of nigerian young adults.

PubMed

Ehizele, Ao; Akhionbare, O

2013-07-01

The major goal of non-surgical periodontal therapy is to reduce or eliminate the subgingival pathogenic microbial flora that is known to be associated with volatile sulfur compounds (VSC). The aim of this study was, therefore, to determine the effect of non-surgical periodontal therapy on the concentration of VSC in mouth air of young adults. Four hundred subjects, grouped into two based on the absence or presence of periodontal diseases, were involved in this study. Basic periodontal examination was used for the grouping. The measurement of the concentration of the VSC in the mouth air of the subjects was done objectively, using the Halimeter, before and after the therapy, and at recall visits 2 weeks and 6 weeks after therapy. Chi-square and Paired t-test were used to find statistical significance. The results revealed that at baseline, 78.7% (48/61) of the subjects who had VSC concentration more than 250 parts per billion (ppb) were from the group with periodontal disease. Immediately after non-surgical periodontal therapy, only 8.5% (17/200) of the subjects with periodontal disease had VSC concentration of more than 250 ppb while all the subjects with no periodontal disease had VSC concentration less than 181 ppb. The same pattern of reduction in the concentration of the VSC and improvement in oral hygiene was also obtained 2 weeks and 6 weeks after therapy. It can be concluded that non-surgical periodontal therapy brought about reduction in the concentration of volatile sulfur compounds in mouth air of young adults.

Chemical evolution of gaseous air pollutants down-wind of tropical megacities: Mexico City case study

NASA Astrophysics Data System (ADS)

Madronich, Sasha

The photochemical evolution of a polluted air parcel originating in a tropical megacity was modeled for 3 days using a box model with detailed gas-phase chemistry. The parcel was initialized with concentrations typically observed in Mexico City for nitrogen oxides (80 parts per billion on a molar basis, or ppbv), carbon monoxide (3000 ppbv), non-methane hydrocarbons (1700 ppb on a carbon basis, or ppbC) and formaldehyde (23.9 ppbv). Vigorous ozone production occurred during day 1, followed by gradual net destruction during the next 2 days. Other major inorganic products were nitric acid and hydrogen peroxide (35 and 16 ppbv, respectively at the end of day 3), while organic products included ketones (83 ppbv), organic hydroperoxides (25 ppbv), peroxyacyl nitrates (28 ppbv), aldehydes (18 ppbv), organic acids (16 ppbv), alkyl nitrates (10 ppbv) and alcohols (0.2 ppbv). Also produced was multitude of different polyfunctional compounds, present individually at small concentrations, but with significant summed concentrations (68, 49 and 1.5 ppbC, respectively, for compounds having 2, 3 or 4 functional groups), which could contribute to the formation of secondary aerosols. The overall reactivity of the parcel (daytime concentrations of hydroxy, hydroperoxy and organic peroxy radicals; and cumulative hydroxyl radical loss rates) remained relatively constant and high on days 2 and 3. This persistent gas-phase reactivity suggests that urban areas could affect regional and global tropospheric chemistry. However, it remains unclear whether heterogeneous losses, on aerosol particles, reduce this reactivity while simultaneously changing aerosol chemical, microphysical and radiative properties relevant to weather and climate.

Determination of Aflatoxin B1 in Smokeless Tobacco Products by use of UHPLC-MS/MS

PubMed Central

Zitomer, Nicholas; Rybak, Michael E.; Li, Zhong; Walters, Matthew J.; Holman, Matthew R.

2017-01-01

We have developed a UHPLC-MS/MS method for the detection and quantitation of aflatoxins in smokeless tobacco products and used it to determine aflatoxin B1 concentrations in 32 smokeless tobacco products commercially available in the US. Smokeless tobacco products were dried, milled and amended with 13C17-labelled internal standards, extracted in water/methanol solution in the presence of a surfactant, isolated through use of immunoaffinity column chromatography and reconstituted in mobile phase prior to UHPLC-MS/MS analysis. Our method was capable of baseline separation of aflatoxins B1, B2, G1 and G2 in a 2.5 min run by use of a fused core C18 column and a water/methanol gradient. MS/MS transition (m/z) 313.3>241.2 was used for aflatoxin B1 quantitation, with 313.3>285.1 used for confirmation. The limit of detection (LOD) for aflatoxin B1 was 0.007 parts per billion (ppb). Method imprecision for aflatoxin B1 (expressed as coefficient of variation) ranged from 5.5% to 9.4%. Spike recoveries were 105–111%. Aflatoxin B1 concentrations in the smokeless tobacco products analysed ranged from

Surfactants from the gas phase may promote cloud droplet formation.

PubMed

Sareen, Neha; Schwier, Allison N; Lathem, Terry L; Nenes, Athanasios; McNeill, V Faye

2013-02-19

Clouds, a key component of the climate system, form when water vapor condenses upon atmospheric particulates termed cloud condensation nuclei (CCN). Variations in CCN concentrations can profoundly impact cloud properties, with important effects on local and global climate. Organic matter constitutes a significant fraction of tropospheric aerosol mass, and can influence CCN activity by depressing surface tension, contributing solute, and influencing droplet activation kinetics by forming a barrier to water uptake. We present direct evidence that two ubiquitous atmospheric trace gases, methylglyoxal (MG) and acetaldehyde, known to be surface-active, can enhance aerosol CCN activity upon uptake. This effect is demonstrated by exposing acidified ammonium sulfate particles to 250 parts per billion (ppb) or 8 ppb gas-phase MG and/or acetaldehyde in an aerosol reaction chamber for up to 5 h. For the more atmospherically relevant experiments, i.e., the 8-ppb organic precursor concentrations, significant enhancements in CCN activity, up to 7.5% reduction in critical dry diameter for activation, are observed over a timescale of hours, without any detectable limitation in activation kinetics. This reduction in critical diameter enhances the apparent particle hygroscopicity up to 26%, which for ambient aerosol would lead to cloud droplet number concentration increases of 8-10% on average. The observed enhancements exceed what would be expected based on Köhler theory and bulk properties. Therefore, the effect may be attributed to the adsorption of MG and acetaldehyde to the gas-aerosol interface, leading to surface tension depression of the aerosol. We conclude that gas-phase surfactants may enhance CCN activity in the atmosphere.

Ag-Modified In2O3/ZnO Nanobundles with High Formaldehyde Gas-Sensing Performance

PubMed Central

Fang, Fang; Bai, Lu; Song, Dongsheng; Yang, Hongping; Sun, Xiaoming; Sun, Hongyu; Zhu, Jing

2015-01-01

Ag-modified In2O3/ZnO bundles with micro/nano porous structures have been designed and synthesized with by hydrothermal method continuing with dehydration process. Each bundle consists of nanoparticles, where nanogaps of 10–30 nm are present between the nanoparticles, leading to a porous structure. This porous structure brings high surface area and fast gas diffusion, enhancing the gas sensitivity. Consequently, the HCHO gas-sensing performance of the Ag-modified In2O3/ZnO bundles have been tested, with the formaldehyde-detection limit of 100 ppb (parts per billion) and the response and recover times as short as 6 s and 3 s, respectively, at 300 °C and the detection limit of 100 ppb, response time of 12 s and recover times of 6 s at 100 °C. The HCHO sensing detect limitation matches the health standard limitation on the concentration of formaldehyde for indoor air. Moreover, the strategy to synthesize the nanobundles is just two-step heating and easy to scale up. Therefore, the Ag-modified In2O3/ZnO bundles are ready for industrialization and practical applications. PMID:26287205

The study of international and interstate transport of ozone in Yuma, Arizona

NASA Astrophysics Data System (ADS)

Li, Y.; Sonenberg, M.; Wood, J. L.; Pearson, C. R.; Colson, H.; Malloy, J. W.; Pace, M.; Mao, F.; Paul, J.; Busby, B. R.; Parkey, B.; Drago, L.; Franquist, T. S.

2017-12-01

In October 2015, EPA reduced the National Ambient Air Quality Standards (NAAQS) for ozone from 75 parts per billion (ppb) to 70 ppb. Meeting the new standard may be extremely challenging for some areas, including rural Yuma County in the State of Arizona. Yuma County faces unique air quality challenges, since it borders the Mexican states of Baja California and Sonora, and the State of California. The present study investigates the contribution of international and interstate transport of ozone and ozone precursors to episodes of elevated ozone concentrations in Yuma. The Arizona Department of Environmental Quality (ADEQ) merged HYSPLIT modeling outputs with two years of hourly ground ozone monitor data to investigate the potential area contributions to ozone concentrations in Yuma County. This analysis found that elevated ozone concentrations in Yuma in 2014 and 2015 frequently coincided with back-trajectories over both California and Mexico, typically favoring Mexico during the spring. In May 2017, ADEQ installed a new ozone monitor in San Luis Rio Colorado, Sonora, Mexico (Latitude: 32.4665, Longitude: -114.7688), which is 29 km south of ozone site in Yuma County. We will present the first simultaneous observations of ozone seasons in Sonora, Mexico, eastern California, and Yuma.

Sensitive detection of formaldehyde using an interband cascade laser near 3.6 μm

DOE PAGES

Ren, Wei; Luo, Longqiang; Tittel, Frank K.

2015-12-31

Here, we report the development of a formaldehyde (H 2CO) trace gas sensor using a continuous wave (CW), thermoelectrically-cooled (TEC), distributed-feedback interband cascade laser (DFB-ICL) at 3.6 μm. Wavelength modulation spectroscopy was used to detect the second harmonic spectra of a strong H 2CO absorption feature centered at 2778.5 cm -1 (3599 nm) in its ν 1 fundamental vibrational band. A compact and novel multipass cell (7.6-cm physical length and 32-ml sampling volume) was implemented to achieve an effective optical path length of 3.75 m. A minimum detection limit of 6 parts per billion (ppb) at an optimum gas pressuremore » of 200 Torr was achieved with a 1-s data acquisition time. An Allan-Werle deviation analysis was performed to investigate the long-term stability of the sensor system and a 1.5 ppb minimum detectable concentration could be achieved by averaging up to 140 s. Absorption interference eeffects from atmospheric H 2O (2%) and CH 4(5 ppm) were also analyzed in this work and proved to be insignificant for the current sensor configuration.« less

Sensitive detection of formaldehyde using an interband cascade laser near 3.6 μm

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ren, Wei; Luo, Longqiang; Tittel, Frank K.

Here, we report the development of a formaldehyde (H 2CO) trace gas sensor using a continuous wave (CW), thermoelectrically-cooled (TEC), distributed-feedback interband cascade laser (DFB-ICL) at 3.6 μm. Wavelength modulation spectroscopy was used to detect the second harmonic spectra of a strong H 2CO absorption feature centered at 2778.5 cm -1 (3599 nm) in its ν 1 fundamental vibrational band. A compact and novel multipass cell (7.6-cm physical length and 32-ml sampling volume) was implemented to achieve an effective optical path length of 3.75 m. A minimum detection limit of 6 parts per billion (ppb) at an optimum gas pressuremore » of 200 Torr was achieved with a 1-s data acquisition time. An Allan-Werle deviation analysis was performed to investigate the long-term stability of the sensor system and a 1.5 ppb minimum detectable concentration could be achieved by averaging up to 140 s. Absorption interference eeffects from atmospheric H 2O (2%) and CH 4(5 ppm) were also analyzed in this work and proved to be insignificant for the current sensor configuration.« less

Beneficial of Coriander Leaves (Coriandrum sativum L.) to Reduce Heavy Metals Contamination in Rod Shellfish

NASA Astrophysics Data System (ADS)

Winarti, S.; Pertiwi, C. N.; Hanani, A. Z.; Mujamil, S. I.; Putra, K. A.; Herlambang, K. C.

2018-01-01

Contamination of heavy metals in certain levels of food can disrupt human health. Heavy metals have toxic properties, cannot be overhauled or destroyed by living organisms, can accumulate in the body of organisms including humans, either directly or indirectly. Heavy metal Hg, Cd, Cr is a very toxic metals (can result in death or health problems that are not recovered in a short time), while heavy metal Co, Pb, Cu toxicity is moderate (can lead to both recoverable and non-recoverable health problems in a relatively long time). Hence the heavy metal contaminating the food must be eliminated or reduced to a safe level. One effort was use coriander leaves to reduce the contamination of heavy metals in fish/shellfish. The objective of the research was to prove the extract of coriander leaves can reduce heavy metal contamination of Pb, Hg and Cu in rod shellfish (lorjuk). The treatment of this research was long soaking in coriander leaves extract that were 0, 30, 60 and 90 minutes. The results showed that the longer time of soaking can decrease Pb level from 4.4 ± 0.424 ppb to 1.7 ± 0.5 ppb, Hg level from 4.11± 0.07 to 1.12± 0.6 ppb, and Cu level from 433.7 ± 0.1 ppb to 117 ± 0.78 ppb. Protein content not significant decrease in rod shellfish (lorjuk) after 90 minutes soaking time, that was from 28.56 ± 0.403% to 26,625 ± 0.19%.

Toluene diisocyanate: Induction of the autotaxin-lysophosphatidic acid axis and its association with airways symptoms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broström, Julia M.; Ye, Zhi-wei; Axmon, Anna

Diisocyanates are industrial chemicals which have a wide range of applications in developed and developing countries. They are notorious lung toxicants and respiratory sensitizers. However, the mechanisms behind their adverse effects are not adequately characterized. Autotaxin (ATX) is an enzyme producing lysophosphatidic acid (LPA), and the ATX-LPA axis has been implicated in lung related inflammatory conditions and diseases, including allergic asthma, but not to toxicity of environmental low-molecular-weight chemicals. We investigated effects of toluene diisocyanate (TDI) on ATX induction in human lung epithelial cell models, and we correlated LPA-levels in plasma to biomarkers of TDI exposure in urine collected frommore » workers exposed to < 5 ppb (parts per billion). Information on workers' symptoms was collected through interviews. One nanomolar TDI robustly induced ATX release within 10 min in vitro. A P2X7- and P2X4-dependent microvesicle formation was implicated in a rapid ATX release and a subsequent protein synthesis. Co-localization between purinergic receptors and ATX was documented by immunofluorescence and confocal microscopy. The release was modulated by monocyte chemoattractant protein-1 (MCP-1) and by extracellular ATP. In workers, we found a dose–response relationship between TDI exposure biomarkers in urine and LPA levels in plasma. Among symptomatic workers reporting “sneezing”, the LPA levels were higher than among non-symptomatic workers. This is the first report indicating induction of the ATX-LPA axis by an environmental low-molecular-weight chemical, and our data suggest a role for the ATX-LPA axis in TDI toxicity. - Highlights: • Human epithelial cells release autotaxin in response to 1 nM toluene diisocyanate (TDI). • The release involves P2X4 and P2X7 receptors and is modulated by ATP and MCP-1. • Lysophosphatidic acid (LPA) was measured in workers exposed to < 5 ppb TDI. • LPA in plasma correlated to TDI exposure biomarkers in workers. • Symptomatic workers had higher LPA levels than those without symptoms.« less

Enhanced xylene removal by photocatalytic oxidation using fiber-illuminated honeycomb reactor at ppb level.

PubMed

Wu, Yi-Ting; Yu, Yi-Hui; Nguyen, Van-Huy; Lu, Kung-Te; Wu, Jeffrey Chi-Sheng; Chang, Luh-Maan; Kuo, Chi-Wen

2013-11-15

The removal of volatile organic compounds (VOCs) at ppb level is one of the most critical challenges in clean rooms for the semiconductor industry. Photocatalytic oxidation is an innovative and promising technology for ppb-level VOCs degradation. We have designed a fiber-illuminated honeycomb reactor (FIHR) in which the removal efficiency of m-xylene is significantly enhanced to 96.5% as compared to 22.0% for UV irradiation only. The results indicate that photocatalysts not only play the role to substantially oxidize m-xylene, but also alter the chemical properties of xylene under UV illumination. Using the FIHR with Mn-TiO2 photocatalyst not only increased the m-xylene removal efficiency, but also increased the CO2 selectivity. Interestingly, Mn-TiO2 in FIHR also showed a very good reusability, 93% removal efficiency was still achieved in 72-h in reaction. Thus, the FIHR gave very high removal efficiency for xylene at ppb level under room temperature. The FIHR has great potential application in the clean room for the air purification system in the future. Copyright © 2013 Elsevier B.V. All rights reserved.

The impact of an urban park on air pollution and noise levels in the Mediterranean city of Tel-Aviv, Israel.

PubMed

Cohen, Pninit; Potchter, Oded; Schnell, Izhak

2014-12-01

This study examines the influence of urban parks on air quality and noise in the city of Tel-Aviv, Israel, by investigation of an urban park, an urban square and a street canyon. Simultaneous monitoring of several air pollutants and noise levels were conducted. The results showed that urban parks can reduce NOx, CO and PM10 and increase O3 concentrations and that park's mitigation effect is greater at higher NOx and PM10 levels. During extreme events, mean values of 413 ppb NOx and 80 μG/m3 PM10 were measured in the street while mean values of 89 ppb NOx and 24 μG/m3 PM10 were measured in the park. Whereas summer highest O3 values of 84 ppb were measured in the street, 94 ppb were measured in the park. The benefit of the urban park in reducing NOx and PM10 concentrations is more significant than the disadvantage of increased O3 levels. Furthermore, urban parks can reduce noise by ∼5 dB(A). Copyright © 2014 Elsevier Ltd. All rights reserved.

Unexpectedly high mercury level in pelleted commercial fish feed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, M.H.; Cech, J.J. Jr.

1998-10-01

An unexpectedly high mercury (Hg) level was found in a pelleted commercial fish feed used to feed fish in laboratory and fish farm settings. Mean total Hg (T-Hg) concentration in the commercial fish pellets was 66 ppb. Mean total selenium (T-Se) concentration in the pellets was 1,120 ppb (ranging from 790 to 1,360 ppb). Total Hg and Se in the whole blood of Sacramento blackfish and in the fish feed were determined by inductively coupled plasma-mass spectrometry (ICP-MS). During a 10-week sampling period T-Hg in blood fluctuated between 35 and 56 ppb. A highly significant, positive correlation was found betweenmore » T-Hg in the fish blood and in the fish feed through the sampling period. On the other hand, no correlation was found between T-Se in the fish feed and T-Hg or T-Se blood level. Researchers working with fish in Hg studies need to know that fish pellets may contain Hg and to consider the influence of these pellets in their results.« less

Impact of kerosene heater usage on indoor NO/sub 2/ exposures in 50 East Tennessee homes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dudney, C.S.; Hawthorne, A.R.; Monar, K.P.

1988-01-01

As part of a study of indoor air quality in 300 houses in Roane County, Tennessee, a special study was made on kerosene heater usage and indoor pollutant levels, with emphasis on NO/sub 2/. Owners of 45 homes with kerosene heaters deployed pairs of passive NO/sub 2/ monitors on a weekly basis for ten weeks and recorded the weekly amount of heater use. Without correcting for house-specific factors, such as air exchange rate, indoor NO/sub 2/ levels were found to increase about 0.3 ppB per h/week of homeowner-reported heater use. In the absence of heater use, NO/sub 2/ levels weremore » about 10 ppB in houses with and without kerosene heaters. In four houses with kerosene heaters and one house without, continuous measurements were made of NO, NO/sub x/, SO/sub 2/, and CO. CO and SO/sub 2/ levels increased threefold and tenfold, respectively, when the heater was operated compared to when it was off. Mean SO/sub 2/ levels during heater operation were 57, 46, and 110 ppB in three houses with radiant heaters and 13.5 ppB in one house with a convective heater. 5 refs., 8 figs., 3 tabs.« less

Climate Change Impacts on Projections of Excess Mortality at 2030 using Spatially-Varying Ozone-Temperature Risk Surfaces

PubMed Central

Wilson, Ander; Reich, Brian J.; Nolte, Christopher G.; Spero, Tanya L.; Hubbell, Bryan; Rappold, Ana G.

2017-01-01

We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995–2005) and near-future (2025–2035) time period while incorporating a nonlinear and synergistic effect of ozone and temperature on mortality. We simulate air quality from climate projections varying only biogenic emissions and holding anthropogenic emissions constant, thus attributing changes in ozone only to changes in climate and independent of changes in air pollutant emissions. We estimate nonlinear, spatially-varying, ozone-temperature risk surfaces for 94 US urban areas using observed data. Using the risk surfaces and climate projections we estimate daily mortality attributable to ozone exceeding 40 ppb (moderate level) and 75 ppb (US ozone NAAQS) for each time period. The average increases in city-specific median April-October ozone and temperature between time periods are 1.02 ppb and 1.94°F; however, the results varied by region. Increases in ozone due to climate change result in an increase in ozone-mortality burden. Mortality attributed to ozone exceeding 40 ppb increases by 7.7% (1.6%, 14.2%). Mortality attributed to ozone exceeding 75 ppb increases by 14.2% (1.6%, 28.9%). The absolute increase in excess ozone mortality is larger for changes in moderate ozone levels, reflecting the larger number of days with moderate ozone levels. PMID:27005744

Investigating the Origin of Chlorohydrocarbons Detected by the Sample Analysis at Mars (SAM) Instrument at Rocknest

NASA Technical Reports Server (NTRS)

Glavin, D.; Archer, D.; Brunner, A.; Buch, A.; Cabane, M.; Coll, P.; Conrad, P.; Coscia, D.; Dworkin J.; Eigenbrode, J.;

Porous titanium particles for acetabular reconstruction in total hip replacement show extensive bony armoring after 15 weeks

PubMed Central

Walschot, Lucas H B; Aquarius, René; Verdonschot, Nico; Buma, Pieter

2014-01-01

Background and purpose — The bone impaction grafting technique restores bone defects in total hip replacement. Porous titanium particles (TiPs) are deformable, like bone particles, and offer better primary stability. We addressed the following questions in this animal study: are impacted TiPs osteoconductive under loaded conditions; do released micro-particles accelerate wear; and are systemic titanium blood levels elevated after implantation of TiPs? Animals and methods — An AAOS type-III defect was created in the right acetabulum of 10 goats weighing 63 (SD 6) kg, and reconstructed with calcium phosphate-coated TiPs and a cemented polyethylene cup. A stem with a cobalt chrome head was cemented in the femur. The goats were killed after 15 weeks. Blood samples were taken pre- and postoperatively. Results — The TiP-graft layer measured 5.6 (SD 0.8) mm with a mean bone ingrowth distance of 2.8 (SD 0.8) mm. Cement penetrated 0.9 (0.3–1.9) mm into the TiPs. 1 reconstruction showed minimal cement penetration (0.3 mm) and failed at the cement-TiP interface. There were no signs of accelerated wear, metallic particle debris, or osteolysis. Median systemic titanium concentrations increased on a log-linear scale from 0.5 (0.3–1.1) parts per billion (ppb) to 0.9 (0.5–2.8) ppb (p = 0.01). Interpretation — Adequate cement pressurization is advocated for impaction grafting with TiPs. After implantation, calcium phosphate-coated TiPs were osteoconductive under loaded conditions and caused an increase in systemic titanium concentrations. However, absolute levels remained low. There were no signs of accelerated wear. A clinical pilot study should be performed to prove that application in humans is safe in the long term. PMID:25238431

Low-level arsenic exposure from drinking water is associated with prostate cancer in Iowa.

PubMed

Roh, Taehyun; Lynch, Charles F; Weyer, Peter; Wang, Kai; Kelly, Kevin M; Ludewig, Gabriele

2017-11-01

Inorganic arsenic is a toxic naturally occurring element in soil and water in many regions of the US including the Midwest. Prostate cancer is the second most common type of cancer in men in Iowa, surpassed only by non-melanotic skin cancer. Epidemiology studies have evaluated arsenic exposure from drinking water and prostate cancer, but most have focused on high-level exposures outside the US. As drinking water from groundwater sources is a major source of arsenic exposure, we conducted an ecologic study to evaluate prostate cancer and arsenic in drinking water from public water sources and private wells in Iowa, where exposure levels are low, but duration of exposure can be long. Arsenic data from public water systems were obtained from the Iowa Safe Drinking Water Information System for the years 1994-2003 and for private wells from two Iowa Well Water Studies, the Iowa Community Private Well Study (ICPWS, 2002-2003) and Iowa Statewide Rural Well Water Survey Phase 2 (SWIRL2, 2006-2008) that provided data for 87 Iowa counties. Prostate cancer incidence data from 2009 to 2013 for Iowa were obtained from Surveillance, Epidemiology and End Results' SEER*Stat software. County averages of water arsenic levels varied from 1.08 to 18.6 ppb, with three counties above the current 10 ppb limit. Based on the tertiles of arsenic levels, counties were divided into three groups: low (1.08-2.06 ppb), medium (2.07-2.98 ppb), and high (2.99-18.6 ppb). Spatial Poisson regression modeling was conducted to estimate the risk ratios (RR) of prostate cancer by tertiles of arsenic level at a county level, adjusted for demographic and risk factors. The RR of prostate cancer were 1.23 (95% CI, 1.16-1.30) and 1.28 (95% CI, 1.21-1.35) in the medium and high groups, respectively, compared to the low group after adjusting for risk factors. The RR increased to 1.36 (95% CI, 1.28-1.45) in the high group when analyses were restricted to aggressive prostate cancers (Gleason score ≥ 7). This study shows a significant dose-dependent association between low-level arsenic exposure and prostate cancer, and if this result is replicated in future individual-level studies, may suggest that 10 ppb is not protective for human health. Copyright © 2017 Elsevier Inc. All rights reserved.

Thermoelectrically cooled water trap

DOEpatents

Micheels, Ronald H [Concord, MA

2006-02-21

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

Silicon chip integrated photonic sensors for biological and chemical sensing

NASA Astrophysics Data System (ADS)

Chakravarty, Swapnajit; Zou, Yi; Yan, Hai; Tang, Naimei; Chen, Ray T.

2016-03-01

We experimentally demonstrate applications of photonic crystal waveguide based devices for on-chip optical absorption spectroscopy for the detection of chemical warfare simulant, triethylphosphate as well as applications with photonic crystal microcavity devices in the detection of biomarkers for pancreatic cancer in patient serum and cadmium metal ions in heavy metal pollution sensing. At mid-infrared wavelengths, we experimentally demonstrate the higher sensitivity of photonic crystal based structures compared to other nanophotonic devices such as strip and slot waveguides with detection down to 10ppm triethylphosphate. We also detected 5ppb (parts per billion) of cadmium metal ions in water at near-infrared wavelengths using established techniques for the detection of specific probe-target biomarker conjugation chemistries.

[Microcystin in plants that treat water for human consumption in a tropical environment: the Metropolitan Area of Costa Rica].

PubMed

Lopez, Adrián Avendaño; Villa, Carolina Arguedas

2006-09-01

We measured microcystin levels in water of the Metropolitan Area of Costa Rica by competitive inhibition ELISA and we quantified total coliforms, fecal coliforms, Escherichia coli (by a Most Probable Number method) and aerobic count. We wanted to identify any cyanotoxin correlation with these parameters, as a public health risk. We sampled in the rainy season of 2003 (April-October) and in the dry season of 2004 (February-March) (30 samples/season). We sampled pre-treated, semi-treated and treated water. Microcystin levels < 0.5 ppb were found in the rainy season (and > 0.5 ppb in the dry season). Dry season levels exceeded World Health Organization limits (1.0 ppb). Cyanotoxins occurred in the Tres Rios plant. We did not find a correlation between these microbiologic parameters of water quality and microcystin levels in water.

Determination of 22 triazole compounds including parent fungicides and metabolites in apples, peaches, flour, and water by liquid chromatography/tandem mass spectrometry.

PubMed

Schermerhorn, Patricia G; Golden, Paul E; Krynitsky, Alexander J; Leimkuehler, William M

2005-01-01

A liquid chromatography/tandem mass spectrometry (LC/MS/MS) method has been developed for the determination of 14 parent triazole fungicides and 8 of their metabolites found in apples, peaches, flour, raw water, and tap water. The triazole fungicides chosen for this multiresidue method development project included propiconazole, fenbuconazole and its RH-9129 and RH-9130 metabolites, cyproconazole, difenoconazole, tebuconazole and its HWG 2061 metabolite, hexaconazole, bromuconazole (both stereoisomers), epoxiconazole, tetraconazole, triticonazole and its RPA-404886 and RPA-406341 metabolites, triadimefon, triadimenol, and myclobutanil. Of special concern to the U.S. Environmental Protection Agency were the metabolites common to all triazole fungicides: free triazole, 1,2,4-triazole (T), and its 2 conjugates: triazolylalanine (TA) and triazolylacetic acid (TAA). These metabolites were the primary focus of this project. All samples we cleaned up by a combination of C18 solid-phase extraction (SPE), mixed-mode cationic SPE, and mixed-mode anionic SPE columns. A triple-stage quadrupole mass spectrometer, equipped with electrospray ionization in the positive-ion mode, was used to determine the compounds of interest. T, TA, and TAA were quantitated using isotopically labeled internal standards (IS), in which the 1,2,4-triazole ring had been synthesized by using 13C and 15N (IS_T, IS_TA, and IS_TAA). These isotopically labeled internal standards were necessary to correct for matrix effects. The T, TA, and TAA metabolites were quantitated at the 25-50 parts-per-billion (ppb) level in food commodities and at 0.50 ppb in water. Recoveries were 70-101% from apples, 60-121% from peaches, 57-118% from flour, 75-99% from raw water, and 79-99% from tap water.

Sensitive Procedures for Determining the Permeation Resistance of Chlorinated Polyethylene Against Liquid Propellants

NASA Technical Reports Server (NTRS)

Waller, Jess M.; Williams, James H.; Fries, Joseph (Technical Monitor)

1999-01-01

The permeation resistance of chlorinated polyethylene (CPE) used in totally encapsulating chemical protective suits against the aerospace fuels hydrazine, monomethylhydrazine, and uns-dimethylhydrazine was determined by measuring the breakthrough time (BT) and time-averaged vapor transmission rate (VTR) using procedures consistent with ASTM F 739 and ASTM F 1383. Two exposure scenarios were simulated: a 2 hour (h) fuel vapor exposure, and a liquid fuel "splash" followed by a 2 h vapor exposure. To simulate internal suit pressure during operation, a positive differential pressure of 0.3 in. water (75 Pa) on the collection side of the permeation apparatus was used. Using the available data, a model was developed to estimate propellant concentrations inside an air-line fed, totally encapsulating chemical protective suit. Concentrations were calculated under simulated conditions of fixed vapor transmission rate, variable breathing air flow rate, and variable splash exposure area. Calculations showed that the maximum allowable permeation rates of hydrazine fuels through CPE were of the order of 0.05 to 0.08 ng/sq cm min for encapsulating suits with low breathing air flow rates (of the order of 5 scfm or 140 L min-1). Above these permeation rates, the 10 parts-per-billion (ppb) threshold limit value time-weighted average could be exceeded. To evaluate suit performance at 10 ppb threshold-limiting value/time-weighted average level concentrations, use of a sensitive analytical method such as cation exchange high performance liquid chromatography with amperometric detection was found to be essential. The analytical detection limit determines the lowest measurable VTR, which in turn governed the lowest per meant concentration that could be calculated inside the totally encapsulating chemical protective suit.

Permeation Resistance of Chlorinated Polyethylene Against Hydrazine Fuels

NASA Technical Reports Server (NTRS)

Waller, J. M.; Williams, J. H.

1999-01-01

The permeation resistance of chlorinated polyethylene (CPE) used in chemical protective clothing against the aerospace fuels hydrazine, monomethylhydrazine (MMH), and uns-dimethylhydrazine (UDMH) was determined by measuring breakthrough times and time-averaged vapor transmission rates using an ASTM F 739 permeation cell. Two exposure scenarios were simulated: a 2 hour (h) fuel vapor exposure, and a liquid fuel "splash" followed by a 2 h vapor exposure. To simulate internal suit pressure during operation, a positive differential pressure of 0.3 in. water (75 Pa) on the collection side of the permeation apparatus was used. Breakthrough was observed after exposure to liquid MMH, and to vapor and liquid UDMH. No breakthrough was observed after exposure to vapor and liquid hydrazine, or vapor MMH. A model was then used to calculate propellant concentrations inside a totally encapsulating chemical protective suit based on the ASTM permeation data obtained in the present study. Concentrations were calculated under conditions of fixed vapor transmission rate, variable breathing air flow rate, and variable splash exposure area. Calculations showed that the maximum allowable permeation rates of hydrazine fuels through CPE were of the order of 0.05 to 0.08 ng sq cm/min for encapsulating suits with low breathing air flow rates (of the order of 5 scfm or 140 L/min). Above these permeation rates, the 10 parts per billion (ppb) threshold limit value time - weighted average could be exceeded for chemical protective suits having a CPE torso. To evaluate suit performance at ppb level concentrations, use of a sensitive analytical method such as cation exchange high performance liquid chromatography with amperometric detection was found to be essential.

The MØLLER experiment at Jefferson Lab: search for physics beyond the Standard Model

NASA Astrophysics Data System (ADS)

van Oers, Willem T. H.

2010-07-01

The MO/LLER experiment at Jefferson Lab will measure the parity-violating analyzing power Az in the scattering of 11 GeV longitudinally polarized electrons from the atomic electrons in a liquid hydrogen target (Mo/ller scattering). In the Standard Model a non-zero Az is due to the interference of the electromagnetic amplitude and the weak neutral current amplitude, the latter mediated by the Z0 boson. Az is predicted to be 35.6 parts per billion (ppb) at the kinematics of the experiment. It is the objective of the experiment to measure Az to a precision of 0.73 ppb. This result would yield a measurement of the weak charge of the electron QWe to a fractional error of 2.3% at an average value Q2 of 0.0056 (GeV/c)2. This in turn will yield a determination of the weak mixing angle sin2θw with an uncertainty of ±0.00026(stat) ±0.00013(syst), comparable to the accuracy of the two best determinations at high energy colliders (at the Z0 pole). Consequently, the result could potentially influence the central value of this fundamental electroweak parameter, which is of critical importance in deciphering any signal of new physics that might be observed at the Large Hadron Collider (LHC). The measurement is sensitive to the interference of the electromagnetic amplitude with new neutral current amplitudes as weak as 10-3 GF from as yet unknown high energy dynamics, a level of sensitivity unlikely to be matched in any experiment measuring a flavor and CP conserving process in the next decade. This provides indirect access to new physics at multi-TeV scales in a manner complementary to direct searches at the LHC.

A passive ozone sampler based on a reaction with iodide.

PubMed

Yanagisawa, Y

1994-02-01

A new passive sampler for ozone and its simple analytical system have been developed. Because it is small and sensitive, the sampler can be used for determining personal exposures to ozone and oxidants and for multilocation measurements. The sampler consists of an electrode, a spacer, and several layers of membrane filters and Teflon meshes. The electrode is a carbon paper disk coated with nylon-6 polymer and potassium iodide. The membrane filters are used to remove interferences. A sampling rate of ozone is controlled by the spacer and Teflon meshes. Iodine is liberated by an oxidation reaction of potassium iodide with ozone. The iodine is stabilized by forming a charge transfer complex with nylon-6 and is accumulated in the nylon-6 layer. The amount of iodine, which is proportional to the level of ozone exposure, is quantified by constant current coulometry. The discharge time of a galvanic battery is measured using the electrode as a positive electrode and a zinc plate as a counter electrode. A time-weighted average concentration of ozone is derived from the discharge time after exposing the electrode to ozone. The effects of various environmental conditions on the sampler's performance were investigated. The results indicated that the sampler showed a linear response to ozone exposure up to 1,450 parts per billion for every hour of use (ppb.hour). The minimum detectable exposure was about 400 ppb.hour. The effects of surface wind velocity, temperature, and humidity were small. However, a relative humidity below 20% resulted in an underestimation of the ozone concentration. Because the electrode requires no pretreatment and the analytical method is very simple, this method is suitable for large-scale studies of personal exposures to ozone and oxidants using multilocation measurements.

Chlordane contamination in selected estuarine and coastal marine finfish and shellfish of New Jersey, USA.

PubMed

Kennish, M J; Ruppel, B E

1996-01-01

Analysis of chlordane contamination in selected finfish and shellfish species from estuarine and coastal marine waters of New Jersey, USA, indicates consistently highest organochlorine pesticide levels in samples from the north and northeast regions of the state. Gas chromatographic analysis of tissue samples from four finfish species (American eel, Anguilla rostrata; bluefish, Pomatomus saltatrix; striped bass, Morone saxatilis; and weakfish, Cynoscion regalis) and one shellfish species (blue crab, Callinectes sapidus) collected at 28 stations throughout the state during the 1986-1987 sampling period and 42 stations during the 1988-1991 sampling period revealed chlordane concentrations ranging from 5 to 2150 ppb wet weight (wet wt). Highest mean concentrations of chlordane (300 ppb wet wt) occurred in American eel from the Camden region, with secondary maxima (100 ppb wet wt) observed in the northeast region. Lower mean concentrations of chlordane (< 100 ppb wet wt) were recorded in tissue samples of other species collected elsewhere in the state. In general, the lowest levels of chlordane contamination (mean < 50 ppb wet wt) were found in samples from the south coast and Delaware regions. A major conclusion of this study is that some commercially and recreationally important finfish and shellfish species in New Jersey waters, especially those which are lipid-rich, have continued to accumulate chlordane from the environment long after restrictive regulations were first placed on its use in the US. The greatest impact of chlordane contamination is nearby metropolitan centers of the state (i.e., New York, Newark, Camden), although the total concentrations of chlordane in tissue samples from these areas are currently far less than the US Food and Drug Administration action level of 300 ppb wet wt.

Nitrogen Dioxide in Indoor Ice Skating Facilities: An International Survey.

PubMed

Brauer, Michael; Lee, Kiyoung; Spengler, John D; Salonen, Raimo O; Pennanen, Arto; Braathen, Ole Anders; Miskovic, Eva Mihalikova And Peter; Nozaki, Atsuo; Tsuzuki, Toshifumi; Rui-Jin, Song; Qing-Xiang, Yang Xu And Zeng; Drahonovska, Hana; Kjaergaard, Søren

1997-10-01

An international survey of nitrogen dioxide (NO 2 ) levels inside indoor ice skating facilities was conducted. One-week average NO 2 concentrations were measured inside and outside of 332 ice rinks located in nine countries. Each rink manager also completed a questionnaire describing the building, the resurfacing machines, and their use patterns. The (arithmetic) mean NO 2 level for all rinks in the study was 228 ppb, with a range of 1-2,680 ppb, based on a sample collected at breathing height and adjacent to the ice surface. The mean of the second indoor sample (collected at a spectator's area) was 221 ppb, with a range of 1-3,175 ppb. The ratio of the indoor to outdoor NO 2 concentrations was above 1 for 95% of the rinks sampled, indicating the presence of an indoor NO 2 source (mean indoor:outdoor ratio = 20). Estimates of short-term NO 2 concentrations indicated that as many as 40% of the sampled rinks would have exceeded the World Health Organization 1-hour guideline value of 213 ppb NO 2 for indoor air. Statistically significant associations were observed between NO 2 levels and the type of fuel used to power the resurfacer, the absence of a catalytic converter on a resurfacer, and the use of an ice edger. There were also indications that decreased use of mechanical ventilation, increased number of resurfacing operations per day, and smaller rink volumes were associated with increased NO 2 levels. In rinks where the main resurfacer was powered by propane, the NO 2 concentrations were higher than in those with gasoline-powered resurfacers, while the latter had NO 2 concentrations higher than in those using diesel. Rinks where the main resurfacer was electric had the lowest indoor NO 2 concentrations, similar to the levels measured outdoor.

Validation of a rapid lateral flow test for the simultaneous determination of β-lactam drugs and flunixin in raw milk.

PubMed

Douglas, David; Banaszewski, Katie; Juskelis, Rima; Al-Taher, Fadwa; Chen, Yang; Cappozzo, Jack; McRobbie, Lindsay; Salter, Robert S

2012-07-01

β-Lactam antibiotics are the most commonly used drugs on dairy farms. β-Lactam residues in milk are kept out of the human milk supply with good agricultural practices and mandatory truck screening performed by the dairy industry under Appendix N of the Pasteurized Milk Ordinance. Flunixin, a nonsteroidal and anti-inflammatory drug, appears in dairy cattle tissue residues with a frequency similar to the occurrence of penicillin G. This creates concern that flunixin residues could be in milk and would go undetected under current milk screening programs. A single test that combines mandatory β-lactam screening with voluntary flunixin screening is an economical approach for monitoring and controlling for potential flunixin or 5-hydroxyflunixin, the primary flunixin metabolite marker in milk. The objective of this study was to validate a β-lactam and flunixin rapid lateral flow test (LFT) and compare the results obtained with a liquid chromatography-triple quadrupole tandem mass spectrometry (LC-MS/MS) method for the simultaneous determination of flunixin and 5-hydroxyflunixin in raw milk with a limit of detection of , 1 ppb, equivalent to 1 ng/ml. Using the LFT, three combined manufactured lots of test strips detected penicillin G at 2.0 ppb, ampicillin at 6.8 ppb, amoxicillin at 5.9 ppb, cephapirin at 13.4 ppb, ceftiofur (total metabolites) at 63 ppb, and 5-hydroxyflunixin at 1.9 ppb at least 90% of the time with 95% confidence. The LFT also detected incurred flunixin milk samples that were analyzed with the LC-MS/MS and diluted to tolerance in raw milk. The detection levels for the LFT are lower than the U.S. safe levels or tolerances and qualify the test to be used in compliance with U.S. milk screening programs.

Observations of ozone and carbon monoxide at Mei-Feng mountain site (2269 m a.s.l.) in Central Taiwan: seasonal variations and influence of Asian continental outflow.

PubMed

Lin, Yu Chi; Lin, Chuan Yao; Lin, Po Hsiung; Engling, Guenter; Lan, Yung-Yao; Kuo, Ten-Ho; Hsu, Wei Ting; Ting, Chia-Chun

2011-07-15

Continuous measurements of ozone (O(3)) and carbon monoxide (CO) were carried out at Mei-Feng (24.05°N, 120.10°E, 2269 m above sea level), a remote mountain site in central Taiwan, to investigate the influence of long-range transported air pollution on O(3) and CO variations in the subtropical Pacific region. Data collected from March 2009 to September 2010 revealed average mixing ratios of 37±14 ppb for O(3) and 188±82 ppb for CO at this remote site. Diurnal variations for both O(3) and CO were observed as well in all seasons. The higher levels for O(3) and CO in the afternoon were attributed to transport of boundary layer pollution to the site during daytime upslope flow. Monthly means of both O(3) and CO showed maxima in spring and in the continental air masses from Southeast Asia, coastal China, and Korea/Japan. On the contrary, the lower O(3) and CO levels found in summer were due to the marine air masses originating from the Philippine Sea and Pacific Ocean. The relationship between O(3) and CO was analyzed, using nighttime data to minimize any local influence. The results showed a fairly good correlation between O(3) and CO from March to September. The contribution of CO from the Asian outflow reached a maximum in spring (88 ppb) and had a minimum in summer (27 ppb). The photochemical buildup of O(3) resulting from anthropogenic emissions in continental Asia was estimated to be 15 ppb in spring, while its production was insignificant, with an average of 4 ppb, in summer. A positive correlation between O(3) and CO plus high ozone levels in springtime suggested that the enhancements of O(3) were likely due to O(3) which was photochemically produced over this region. Copyright © 2011 Elsevier B.V. All rights reserved.

The effect of aldicarb on nematode population and its persistence in carrots, soil and hydroponic solution.

PubMed

Lue, L P; Lewis, C C; Melchor, V E

1984-04-01

Aldicarb, Temik 15 G, was incorporated in furrows at 3.37 and 6.73 kg ai (active ingredient)/ha and carrots (Daucus carota L.) were directly seeded on the same day. The numbers of nematode larvae were significantly suppressed in the treated plots; averages were 249, 74, and 51/50 cc soil samples for control (0), 3.37 and 6.73 kg ai/ha, respectively. Aldicarb treatment resulted in a 28% yield increase as compared to the untreated. Aldicarb residue in carrots was 28 ppb for the low treatment and 46 ppb for the high. Residual levels in soil of high treatment declined from 61 to 31 ppb during two weeks prior to harvest, meanwhile, those in the low decreased slightly from 13 to 12 ppb. Carrots placed in hydroponic solution containing aldicarb 14.5 ppm for 6 days, had an aldicarb residue of 10.26 ppb and the hydroponic solution, 2.7 ppb. Persistence of aldicarb residue was in carrot greater than in soil greater than in hydroponic solution.

Charge-Transfer-Induced Fluorescence Quenching of Anthracene Derivatives and Selective Detection of Picric Acid.

PubMed

Santra, Dines Chandra; Bera, Manas Kumar; Sukul, Pradip Kumar; Malik, Sudip

2016-02-01

2,6-Divinylpyridine-appended anthracene derivatives flanked by two alkyl chains at the 9,10-position of the core have been designed, synthesized, and characterized by NMR, MALDI-TOF, FTIR, and single-crystal XRD. These anthracene derivatives are able to recognize picric acid (2,4,6-trinitrophenol, PA) selectively down to parts per billion (ppb) level in aqueous as well as nonaqueous medium. Fluorescence emission of these derivatives in solution is significantly quenched by adding trace amounts of PA, even in the presence of other competing analogues, such as 2,4-dinitrophenol (2,4-DNP), 4-nitrophenol (NP), nitrobenzene (NB), benzoic acid (BA), and phenol (PH). The high sensitivity of these derivatives toward PA is considered as a combined effect of the proton-induced intramolecular charge transfer (ICT) as well as electron transfer from the electron-rich anthracene to the electron-deficient PA. Moreover, visual detection of PA has been successfully demonstrated in the solid state by using different substrates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Ozone-initiated chemistry in an occupied simulated aircraft cabin.

PubMed

Weschler, Charles J; Wisthaler, Armin; Cowlin, Shannon; Tamás, Gyöngyi; Strøm-Tejsen, Peter; Hodgson, Alfred T; Destaillats, Hugo; Herrington, Jason; Zhang, Junfeng; Nazaroff, William W

2007-09-01

We have used multiple analytical methods to characterize the gas-phase products formed when ozone was added to cabin air during simulated 4-hour flights that were conducted in a reconstructed section of a B-767 aircraft containing human occupants. Two separate groups of 16 females were each exposed to four conditions: low air exchange (4.4 (h-1)), <2 ppb ozone; low air exchange, 61-64 ppb ozone; high air exchange (8.8 h(-1)), <2 ppb ozone; and high air exchange, 73-77 ppb ozone. The addition of ozone to the cabin air increased the levels of identified byproducts from approximately 70 to 130 ppb at the lower air exchange rate and from approximately 30 to 70 ppb at the higher air exchange rate. Most of the increase was attributable to acetone, nonanal, decanal, 4-oxopentanal (4-OPA), 6-methyl-5-hepten-2-one (6-MHO), formic acid, and acetic acid, with 0.25-0.30 mol of quantified product volatilized per mol of ozone consumed. Several of these compounds reached levels above their reported odor thresholds. Most byproducts were derived from surface reactions with occupants and their clothing, consistent with the inference that occupants were responsible for the removal of >55% of the ozone in the cabin. The observations made in this study have implications for other indoor settings. Whenever human beings and ozone are simultaneously present, one anticipates production of acetone, nonanal, decanal, 6-MHO, geranyl acetone, and 4-OPA.

Increased sensitivity of OSHA method analysis of diacetyl and 2,3-pentanedione in air

PubMed Central

LeBouf, Ryan; Simmons, Michael

2018-01-01

Gas chromatography/mass spectrometry (GC/MS) operated in selected ion monitoring mode was used to enhance the sensitivity of OSHA Methods 1013/1016 for measuring diacetyl and 2,3-pentanedione in air samples. The original methods use flame ionization detection which cannot achieve the required sensitivity to quantify samples at or below the NIOSH recommended exposure limits (REL: 5 ppb for diacetyl and 9.3 ppb for 2,3-pentanedione) when sampling for both diacetyl and 2,3-pentanedione. OSHA Method 1012 was developed to measure diacetyl at lower levels but requires an electron capture detector, and a sample preparation time of 36 hours. Using GC/MS allows detection of these two alpha-diketones at lower levels than OSHA Method 1012 for diacetyl and OSHA Method 1016 for 2,3-pentanedione. Acetoin and 2,3-hexanedione may also be measured using this technique. Method quantification limits were 1.1 ppb for diacetyl (22% of the REL), 1.1 ppb for 2,3-pentanedione (12% of the REL), 1.1 ppb for 2,3-hexanedione, and 2.1 ppb for acetoin. Average extraction efficiencies above the limit of quantitation were 100% for diacetyl, 92% for 2,3-pentanedione, 89% for 2,3-hexanedione, and 87% for acetoin. Mass spectrometry with OSHA Methods 1013/1016 could be used by analytical laboratories to provide more sensitive and accurate measures of exposure to diacetyl and 2,3-pentanedione. PMID:27792470

Increased sensitivity of OSHA method analysis of diacetyl and 2,3-pentanedione in air.

PubMed

LeBouf, Ryan; Simmons, Michael

2017-05-01

Gas chromatography/mass spectrometry (GC/MS) operated in selected ion monitoring mode was used to enhance the sensitivity of OSHA Methods 1013/1016 for measuring diacetyl and 2,3-pentanedione in air samples. The original methods use flame ionization detection which cannot achieve the required sensitivity to quantify samples at or below the NIOSH recommended exposure limits (REL: 5 ppb for diacetyl and 9.3 ppb for 2,3-pentanedione) when sampling for both diacetyl and 2,3-pentanedione. OSHA Method 1012 was developed to measure diacetyl at lower levels but requires an electron capture detector, and a sample preparation time of 36 hours. Using GC/MS allows detection of these two alpha-diketones at lower levels than OSHA Method 1012 for diacetyl and OSHA Method 1016 for 2,3-pentanedione. Acetoin and 2,3-hexanedione may also be measured using this technique. Method quantification limits were 1.1 ppb for diacetyl (22% of the REL), 1.1 ppb for 2,3-pentanedione (12% of the REL), 1.1 ppb for 2,3-hexanedione, and 2.1 ppb for acetoin. Average extraction efficiencies above the limit of quantitation were 100% for diacetyl, 92% for 2,3-pentanedione, 89% for 2,3-hexanedione, and 87% for acetoin. Mass spectrometry with OSHA Methods 1013/1016 could be used by analytical laboratories to provide more sensitive and accurate measures of exposure to diacetyl and 2,3-pentanedione.

Photochemical model evaluation of the ground-level ozone impacts on ambient air quality and vegetation health in the Alberta oil sands region: Using present and future emission scenarios

NASA Astrophysics Data System (ADS)

Vijayaraghavan, Krish; Cho, Sunny; Morris, Ralph; Spink, David; Jung, Jaegun; Pauls, Ron; Duffett, Katherine

2016-09-01

One of the potential environmental issues associated with oil sands development is increased ozone formation resulting from NOX and volatile organic compound emissions from bitumen extraction, processing and upgrading. To manage this issue in the Athabasca Oil Sands Region (AOSR) in northeast Alberta, a regional multi-stakeholder group, the Cumulative Environmental Management Association (CEMA), developed an Ozone Management Framework that includes a modelling based assessment component. In this paper, we describe how the Community Multi-scale Air Quality (CMAQ) model was applied to assess potential ground-level ozone formation and impacts on ambient air quality and vegetation health for three different ozone precursor cases in the AOSR. Statistical analysis methods were applied, and the CMAQ performance results met the U.S. EPA model performance goal at all sites. The modelled 4th highest daily maximum 8-h average ozone concentrations in the base and two future year scenarios did not exceed the Canada-wide standard of 65 ppb or the newer Canadian Ambient Air Quality Standards of 63 ppb in 2015 and 62 ppb in 2020. Modelled maximum 1-h ozone concentrations in the study were well below the Alberta Ambient Air Quality Objective of 82 ppb in all three cases. Several ozone vegetation exposure metrics were also evaluated to investigate the potential impact of ground-level ozone on vegetation. The chronic 3-months SUM60 exposure metric is within the CEMA baseline range (0-2000 ppb-hr) everywhere in the AOSR. The AOT40 ozone exposure metric predicted by CMAQ did not exceed the United Nations Economic Commission for Europe (UN/ECE) threshold of concern of 3000 ppb-hr in any of the cases but is just below the threshold in high-end future emissions scenario. In all three emission scenarios, the CMAQ predicted W126 ozone exposure metric is within the CEMA baseline threshold of 4000 ppb-hr. This study outlines the use of photochemical modelling of the impact of an industry (oil sands) on ground-level ozone levels as an air quality management tool in the AOSR. It allows an evaluation of the relationships between the pollutants emitted to the atmosphere and potential ground level ozone concentrations throughout the AOSR thereby extending the spatial coverage of the results beyond the monitoring network and also allowing an assessment of the potential impacts of possible future emission cases.

High-precision quasi-continuous atmospheric greenhouse gas measurements at Trainou tower (Orléans forest, France)

NASA Astrophysics Data System (ADS)

Schmidt, M.; Lopez, M.; Yver Kwok, C.; Messager, C.; Ramonet, M.; Wastine, B.; Vuillemin, C.; Truong, F.; Gal, B.; Parmentier, E.; Cloué, O.; Ciais, P.

2014-07-01

Results from the Trainou tall tower measurement station installed in 2006 are presented for atmospheric measurements of CO2, CH4, N2O, SF6, CO, H2 mole fractions and radon-222 activity. Air is sampled from four sampling heights (180, 100, 50 and 5 m) of the Trainou 200 m television tower in the Orléans forest in France (47°57'53" N, 2°06'45" E, 131 m a.s.l.). The station is equipped with a custom-built CO2 analyser (CARIBOU), which is based on a commercial non-dispersive, infrared (NDIR) analyser (Licor 6252), and a coupled gas chromatography (GC) system equipped with an electron capture detector (ECD) and a flame ionization detector (FID) (HP6890N, Agilent) and a reduction gas detector (PP1, Peak Performer). Air intakes, pumping and air drying system are shared between the CARIBOU and the GC systems. The ultimately achieved short-term repeatability (1 sigma, over several days) for the GC system is 0.05 ppm for CO2, 1.4 ppb for CH4, 0.25 ppb for N2O, 0.08 ppb for SF6, 0.88 ppb for CO and 3.8 for H2. The repeatability of the CARIBOU CO2 analyser is 0.06 ppm. In addition to the in situ measurements, weekly flask sampling is performed, and flask air samples are analysed at the Laboratoire des Sciences du Climat et de l'Environnement (LSCE) central laboratory for the same species as well for stable isotopes of CO2. The comparison between in situ measurements and the flask sampling showed averaged differences of 0.08 ± 1.40 ppm for CO2, 0.7 ± 7.3 ppb for CH4, 0.6 ± 0.6 ppb for N2O, 0.01 ± 0.10 ppt for SF6, 1.5± 5.3 ppb for CO and 4.8± 6.9 ppb for H2 for the years 2008-2012. At Trainou station, the mean annual increase rates from 2007 to 2011 at the 180 m sampling height were 2.2 ppm yr-1 for CO2, 4 ppb yr-1 for CH4, 0.78 ppb yr-1 for N2O and 0.29 ppt yr-1 for SF6. For all species, the 180 m sampling level showed the smallest diurnal variation. Mean diurnal gradients between the 50 m and the 180 m sampling level reached up to 30 ppm CO2, 15 ppm CH4 or 0.5 ppb N2O during nighttime whereas the mean gradients are smaller than 0.5 ppm for CO2 and 1.5 ppb for CH4 during afternoon.

Low level vapor verification of monomethyl hydrazine

NASA Technical Reports Server (NTRS)

Mehta, Narinder

1990-01-01

The vapor scrubbing system and the coulometric test procedure for the low level vapor verification of monomethyl hydrazine (MMH) are evaluated. Experimental data on precision, efficiency of the scrubbing liquid, instrument response, detection and reliable quantitation limits, stability of the vapor scrubbed solution, and interference were obtained to assess the applicability of the method for the low ppb level detection of the analyte vapor in air. The results indicated that the analyte vapor scrubbing system and the coulometric test procedure can be utilized for the quantitative detection of low ppb level vapor of MMH in air.

Identification and level of organochlorine insecticide contamination in groundwater and iridology analysis for people in Upper Citarum cascade

NASA Astrophysics Data System (ADS)

Oginawati, K.; Pratama, M. A.

2016-03-01

Organochlorines are the main pollutants in the class of persistent organic pollutants which are types of pollutants that are being questioned worldwide due to chronic persistence, toxicity and bioaccumulation. Human around the Citarum River are still using groundwater as a drinking source. It is very risky for people health that consume groundwater because in 2009 the application of organochlorine still found in the Upper Citarum watershed rice field and had potential to contaminate groundwater. Groundwater was analyzed with nine species belonging to the organochlorine pollutants Organic Peristent types. 7 types of organochlorinesAldrin was detected with an average concentration of 0.09 ppb, dieldrin with an average concentration of 24 ppb, heptaklor with an average concentration of 0.51 ppb, with concentrations of endosulfan on average 0.73 ppb, DDT with average concentration of 0.13 ppb, Lindan with an average concentration of 1.2 ppb, endrin with an average concentration of 0.03 ppb. Types with the highest concentration of organochlorine a lindan and endosulfan. Residues of aldrin, dieldrin and heptaklor in groundwater already exceeds the quality standards for drinking water Permenkes 492/2010. Based on the iridology analysis obtained several systems are expected to nervous, immune and reproductive system disorders and toxin deposits under the skin.

Mycotoxin Cocktail in the Samples of Oilseed Cake from Early Maturing Cotton Varieties Associated with Cattle Feeding Problems.

PubMed

Yunus, Agha W; Sulyok, Michael; Böhm, Josef

2015-06-12

Cottonseed cake in South East Asia has been associated with health issues in ruminants in the recent years. The present study was carried out to investigate the health issues associated with cottonseed cake feeding in dairy animals in Pakistan. All the cake samples were confirmed to be from early maturing cotton varieties (maturing prior to or during Monsoon). A survey of the resource persons indicated that the feeding problems with cottonseed cake appeared after 4-5 months of post-production storage. All the cake samples had heavy bacterial counts, and contaminated with over a dozen different fungal genera. Screening for toxins revealed co-contamination with toxic levels of nearly a dozen mycotoxins including aflatoxin B1 + B2 (556 to 5574 ppb), ochratoxin A + B (47 to 2335 ppb), cyclopiazonic acid (1090 to 6706 ppb), equisetin (2226 to 12672 ppb), rubrofusarin (81 to 1125), tenuazonic acid (549 to 9882 ppb), 3-nitropropionic acid (111 to 1032 ppb), and citrinin (29 to 359 ppb). Two buffalo calves in a diagnostic feed trial also showed signs of complex toxicity. These results indicate that inappropriate processing and storage of the cake, in the typical conditions of the subcontinent, could be the main contributory factors regarding the low quality of cottonseed cake.

Chronic respiratory effects of indoor formaldehyde exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krzyzanowski, M.; Quackenboss, J.J.; Lebowitz, M.D.

The relation of chronic respiratory symptoms and pulmonary function to formaldehyde (HCHO) in homes was studied in a sample of 298 children (6-15 years of age) and 613 adults. HCHO measurements were made with passive samplers during two 1-week periods. Data on chronic cough and phlegm, wheeze, attacks of breathlessness, and doctor diagnoses of chronic bronchitis and asthma were collected with self-completed questionnaires. Peak expiratory flow rates (PEFR) were obtained during the evenings and mornings for up to 14 consecutive days for each individual. Significantly greater prevalence rates of asthma and chronic bronchitis were found in children from houses withmore » HCHO levels 60-120 ppb than in those less exposed, especially in children also exposed to environmental tobacco smoke. In children, levels of PEFR decreased linearly with HCHO exposure, with the estimated decrease due to 60 ppb of HCHO equivalent to 22% of PEFR level in nonexposed children. The effects in asthmatic children exposed to HCHO below 50 ppb were greater than in healthy ones. The effects in adults were less evident: decrements in PEFR due to HCHO over 40 ppb were seen only in the morning, and mainly in smokers.« less

Climate change impacts on projections of excess mortality at ...

EPA Pesticide Factsheets

We project the change in ozone-related mortality burden attributable to changes in climate between a historical (1995-2005) and near-future (2025-2035) time period while incorporating a non-linear and synergistic effect of ozone and temperature on mortality. We simulate air quality from climate projections varying only biogenic emissions and holding anthropogenic emissions constant, thus attributing changes in ozone only to changes in climate and independent of changes in air pollutant emissions. We estimate non-linear, spatially varying, ozone-temperature risk surfaces for 94 US urban areas using observeddata. Using the risk surfaces and climate projections we estimate daily mortality attributable to ozone exceeding 40 p.p.b. (moderate level) and 75 p.p.b. (US ozone NAAQS) for each time period. The average increases in city-specific median April-October ozone and temperature between time periods are 1.02 p.p.b. and 1.94 °F; however, the results variedby region . Increases in ozone because of climate change result in an increase in ozone mortality burden. Mortality attributed to ozone exceeding 40 p.p.b. increases by 7.7% (1 .6-14.2%). Mortality attributed to ozone exceeding 75 p.p.b. increases by 14.2% (1.628.9%). The absolute increase in excess ozone mortality is larger for changes in moderate ozone levels, reflecting the larger number of days with moderate ozone levels. In this study we evaluate changes in ozone related mortality due to changes in biogenic f

Embryonic-only arsenic exposure in killifish (Fundulus heteroclitus) reduces growth and alters muscle IGF levels one year later.

PubMed

Szymkowicz, Dana B; Sims, Kaleigh C; Castro, Noemi M; Bridges, William C; Bain, Lisa J

2017-05-01

Arsenic is a contaminant of drinking water and crops in many parts of the world. Epidemiological studies have shown that arsenic exposure is linked to decreased birth weight, weight gain, and proper skeletal muscle function. The goal of this study was to use killifish (Fundulus heteroclitus) as a model to determine the long-term effects of embryonic-only arsenic exposure on muscle growth and the insulin-like growth factor (IGF) pathway. Killifish embryos were exposed to 0, 50, 200 or 800ppb As III from fertilization until hatching. Juvenile fish were reared in clean water and muscle samples were collected at 16, 28, 40 and 52 weeks of age. There were significant reductions in condition factors, ranging from 12 to 17%, in the fish exposed to arsenic at 16, 28 and 40 weeks of age. However, by 52 weeks, no significant changes in condition factors were seen. Alterations in IGF-1R and IGF-1 levels were assessed as a potential mechanism by which growth was reduced. While there no changes in hepatic IGF-1 transcripts, skeletal muscle cells can also produce their own IGF-1 and/or alter IGF-1 receptor levels to help enhance growth. After a 200 and 800ppb embryonic exposure, fish grown in clean water for 16 weeks had IGF-1R transcripts that were 2.8-fold and 2-fold greater, respectively, than unexposed fish. Through 40 weeks of age, IGF1-R remained elevated in the 200ppb and 800ppb embryonic exposure groups by 1.8-3.9-fold, while at 52 weeks of age, IGF-1R levels were still significantly increased in the 800ppb exposure group. Skeletal muscle IGF-1 transcripts were also significantly increased by 1.9-5.1 fold through the 52 weeks of grow-out in clean by water in the 800ppb embryonic exposure group. Based on these results, embryonic arsenic exposure has long-term effects in that it reduces growth and increases both IGF-1 and IGF-1R levels in skeletal muscle even 1year after the exposure has ended. Copyright © 2017 Elsevier B.V. All rights reserved.

Trends analyses of 30 years of ambient 8 hour ozone and precursor monitoring data in the South Central U.S.: progress and challenges.

PubMed

Sather, Mark E; Cavender, Kevin

2016-07-13

In the last 30 years ambient ozone concentrations have notably decreased in the South Central U.S. Yet, current ambient ozone concentrations measured over the past three years 2013-2015 in this area of the U.S. are not meeting the U.S. 2015 8 hour ozone standard of 70 parts per billion (ppb). This paper provides an update on long-term trends analyses of ambient 8 hour ozone and ozone precursor monitoring data collected over the past 30 years (1986-2015) in four South Central U.S. cities, following up on two previously published reviews of 20 and 25 year trends for these cities. All four cities have benefitted from national ozone precursor controls put in place during the 1990s and 2000s involving cleaner vehicles (vehicle fleet turnover/replacement over time), cleaner fuels, cleaner gasoline and diesel engines, and improved inspection/maintenance programs for existing vehicles. Additional ozone precursor emission controls specific to each city are detailed in this paper. The controls have resulted in impressive ambient ozone and ambient ozone precursor concentration reductions in the four South Central U.S. cities over the past 30 years, including 31-70% ambient nitrogen oxides (NOx) concentration declines from historical peaks to the present, 43-72% volatile organic compound (VOC) concentration declines from historical peaks to the present, a related 45-76% VOC reactivity decline for a subset of VOC species from historical peaks to the present, and an 18-38 ppb reduction in city 8 hour ozone design value concentrations. A new challenge for each of the four South Central U.S. cities will be meeting the U.S. 2015 8 hour ozone standard of 70 ppb.

Maternal exposure to brominated flame retardants and infant Apgar scores.

PubMed

Terrell, Metrecia L; Hartnett, Kathleen P; Lim, Hyeyeun; Wirth, Julie; Marcus, Michele

2015-01-01

Brominated flame retardants (BFRs) and other persistent organic pollutants have been associated with adverse health outcomes in humans and may be particularly toxic to the developing fetus. We investigated the association between in utero polybrominated biphenyl (PBB) and polychlorinated biphenyl (PCB) exposures and infant Apgar scores in a cohort of Michigan residents exposed to PBB through contaminated food after an industrial accident. PBB and PCB concentrations were measured in serum at the time the women were enrolled in the cohort. PBB concentrations were also estimated at the time of conception for each pregnancy using a validated elimination model. Apgar scores, a universal measure of infant health at birth, measured at 1 and 5min, were taken from birth certificates for 613 offspring born to 330 women. Maternal PCB concentrations at enrollment were not associated with below-median Apgar scores in this cohort. However, maternal PBB exposure was associated with a dose-related increase in the odds of a below-median Apgar score at 1min and 5min. Among infants whose mothers had an estimated PBB at conception above the limit of detection of 1 part per billion (ppb) to <2.5ppb, the odds ratio=2.32 (95% CI: 1.22-4.40); for those with PBB⩾2.5ppb the OR=2.62 (95% CI: 1.38-4.96; test for trend p<0.01). Likewise, the odds of a below-median 5min Apgar score increased with higher maternal PBB at conception. It remains critical that future studies examine possible relationships between in utero exposures to brominated compounds and adverse health outcomes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Effect of Non-Surgical Periodontal Therapy on the Concentration of Volatile Sulfur Compound in Mouth Air of a Group of Nigerian Young Adults

PubMed Central

Ehizele, AO; Akhionbare, O

2013-01-01

Background: The major goal of non-surgical periodontal therapy is to reduce or eliminate the subgingival pathogenic microbial flora that is known to be associated with volatile sulfur compounds (VSC). Aim: The aim of this study was, therefore, to determine the effect of non-surgical periodontal therapy on the concentration of VSC in mouth air of young adults. Subjects and Methods: Four hundred subjects, grouped into two based on the absence or presence of periodontal diseases, were involved in this study. Basic periodontal examination was used for the grouping. The measurement of the concentration of the VSC in the mouth air of the subjects was done objectively, using the Halimeter, before and after the therapy, and at recall visits 2 weeks and 6 weeks after therapy. Chi-square and Paired t-test were used to find statistical significance. Results: The results revealed that at baseline, 78.7% (48/61) of the subjects who had VSC concentration more than 250 parts per billion (ppb) were from the group with periodontal disease. Immediately after non-surgical periodontal therapy, only 8.5% (17/200) of the subjects with periodontal disease had VSC concentration of more than 250 ppb while all the subjects with no periodontal disease had VSC concentration less than 181 ppb. The same pattern of reduction in the concentration of the VSC and improvement in oral hygiene was also obtained 2 weeks and 6 weeks after therapy. Conclusion: It can be concluded that non-surgical periodontal therapy brought about reduction in the concentration of volatile sulfur compounds in mouth air of young adults. PMID:24116328

Smartphone app-based/portable sensor for the detection of fluoro-surfactant PFOA.

PubMed

Fang, Cheng; Zhang, Xian; Dong, Zhaomin; Wang, Liang; Megharaj, Mallavarapu; Naidu, Ravi

2018-01-01

We developed a smartphone app-based monitoring tool for the detection of anionic surfactants (AS), including perfluorooctanoic acid (PFOA) and perfluorooctane sulfonate (PFOS). Akin to the methylene blue active substances (MBAS), liquid-phase extraction (LPE) is employed to extract the hydrophobic ion-pair of dye (ethyl violet)-AS to an organic phase (ethyl acetate). The colour (RGB) of the organic phase is read using a smartphone camera with the help of a reading kit. The value of RGB is carefully corrected and linked to the concentration of ASs with a standard deviation of <10% in the 10-1000 ppb (part per billion) range. In order to avoid the interference arising from inorganic anions (such as those found in tap water and groundwater), the water sample is pre-treated either by solid-phase extraction (SPE), which takes ∼30 min, or by dual liquid-phase extraction (dual-LPE, developed by us), which takes ∼5 min. In the latter case, the organic phase of the first LPE (equilibrium with water sample) is transferred and subjected to a second LPE (equilibrium with Milli-Q water) to remove any potential background interference. In the meantime, SPE can also pre-concentrate ASs at 100-1000 times (in volume) to benefit the sensitivity. Consequently, our smartphone app can detect PFOA spiked in tap/groundwater with an LOD of 10 ppb (∼12 nM, dual-LPE of ∼5 min), or 0.5 ppb (∼1.2 nM, SPE of ∼3 h), suggesting that it has the potential to succeed as a pre-screening tool for on-site application and in common laboratory tests. Copyright © 2017 Elsevier Ltd. All rights reserved.

The potential near-source ozone impacts of upstream oil and gas industry emissions.

PubMed

Olaguer, Eduardo P

2012-08-01

Increased drilling in urban areas overlying shale formations and its potential impact on human health through decreased air quality make it important to estimate the contribution of oil and gas activities to photochemical smog. Flares and compressor engines used in natural gas operations, for example, are large sources not only of NOx but also offormaldehyde, a hazardous air pollutant and powerful ozone precursor We used a neighborhood scale (200 m horizontal resolution) three-dimensional (3D) air dispersion model with an appropriate chemical mechanism to simulate ozone formation in the vicinity ofa hypothetical natural gas processing facility, based on accepted estimates of both regular and nonroutine emissions. The model predicts that, under average midday conditions in June, regular emissions mostly associated with compressor engines may increase ambient ozone in the Barnett Shale by more than 3 ppb beginning at about 2 km downwind of the facility, assuming there are no other major sources of ozone precursors. Flare volumes of 100,000 cubic meters per hour ofnatural gas over a period of 2 hr can also add over 3 ppb to peak 1-hr ozone somewhatfurther (>8 km) downwind, once dilution overcomes ozone titration and inhibition by large flare emissions of NOx. The additional peak ozone from the hypothetical flare can briefly exceed 10 ppb about 16 km downwind. The enhancements of ambient ozone predicted by the model are significant, given that ozone control strategy widths are of the order of a few parts per billion. Degrading the horizontal resolution of the model to 1 km spuriously enhances the simulated ozone increases by reducing the effectiveness of ozone inhibition and titration due to artificial plume dilution.

Cup inclination angle of greater than 50 degrees increases whole blood concentrations of cobalt and chromium ions after metal-on-metal hip resurfacing.

PubMed

Hart, A J; Buddhdev, P; Winship, P; Faria, N; Powell, J J; Skinner, J A

2008-01-01

A cup inclination angle greater than 45 degrees is associated with increased wear rates of metal on polyethylene (MOP) hip replacements. The same maybe true for metal on metal (MOM) hips yet this has not been clearly shown. We measured the acetabular inclination angle from plain radiographs, and whole blood metal ion levels using Inductively Coupled Plasma Mass Spectrometry of 26 patients (mean Harris Hip Score 94 and mean time post op of 22 months) with Birmingham Hip Resurfacings. We identified a threshold level of 50 degrees cup inclination. Below this threshold, the mean whole blood cobalt and chromium were 1.6 ppb and 1.88 ppb respectively; above this threshold, the mean blood cobalt and chromium were 4.45 ppb and 4.3 ppb respectively. These differences were significant cobalt (p<0.01) and chromium (p=0.01). All patients above the threshold had metal levels greater than any of the patients below the threshold. For 14 patients, who returned one year later for a repeat blood metal level measurement, cobalt and chromium levels were very similar. The effect of an acetabular inclination angle of greater than 50 degrees on wear rates of MOM hips, as measured through blood metal ion levels, appears to be similar to that seen with MOP hips. Additionally, our new analytical methods may allow blood metal levels to be used as a realistic biomarker of in vivo wear rate of MOM hips. The implication is that metal levels can be minimised with optimal orientation of the acetabular component.

Investigations into the relations between respiratory illness in children, gas cooking and nitrogen dioxide in the U.K.

PubMed

Melia, R J; Florey, C D; Chinn, S; Morris, R W; Goldstein, B D; John, H H; Clark, D

1985-08-01

In 1977 an association was reported between the prevalence of respiratory illness and use of gas for cooking at home in a national sample of six to 11 year olds living in England and Scotland (p less than .10). Other variables such as social class and number of cigarette smokers at home did not seem to explain the association. As the gas cooker is an unflued appliance emitting a variety of pollutants during gas combustion it was suggested that indoor air pollution might explain the finding. Nitrogen dioxide (NO2) was suspected so a series of studies was conducted to investigate the distribution of levels of NO2 in the home, the relative contribution of sources of NO2 to indoor exposure and the relation between respiratory illness in six to 11 year olds and levels of NO2 in the home. The gas cooker was found to be one of the main sources of NO2 in the home. Winter weekly averages in kitchens with gas cookers had a mean of 112.2 ppb (n = 428, range 5-317 ppb). Levels in electric cooking kitchens were significantly lower (n = 87, mean 18 ppb, range 6-188 ppb). Studies of health indicated a relation between respiratory illness and bedroom levels of NO2 over the range 4-169 ppb (p .10). Results for living room levels of NO2 suggested a similar but non-significant relationship (p greater than .10). No relation was found for kitchen levels of NO2. For schoolchildren any effect on health from indoor NO2 is likely to be weak. However other sections of the population such as infants and the elderly who may spend more time indoors and are particularly susceptible to respiratory illness need to be studied to assess fully the impact that NO2 may be having on health.

Allergen exposure modifies the relation of sensitization to FENO levels in children at risk for allergy and asthma

PubMed Central

Sordillo, Joanne E; Webb, Tara; Kwan, Doris; Kamel, Jimmy; Hoffman, Elaine; Milton, Donald K; Gold, Diane R

2011-01-01

Background Studies on airway inflammation, measured as fraction exhaled nitric oxide (FENO), have focused on its relation to control of asthma, but the contribution of allergen exposure to elevation of FENO is unknown. Objective We evaluated (1) whether FENO was elevated in children with allergic sensitization or asthma; (2) whether specific allergen exposure increased FENO levels in sensitized, but not in unsensitized children; and (3) whether sedentary behavior increased FENO, independent of allergen exposures. Methods At age 12, in a birth cohort of children with parental history of allergy or asthma, we measured bed dust allergen (dust mite, cat, cockroach) by ELISA; specific allergic sensitization primarily by specific IgE ; and respiratory disease (current asthma, rhinitis, and wheeze) and hours of TV viewing/video game playing by questionnaire. Children performed spirometry maneuvers before and after bronchodilator responses, and had FENO measured using electrochemical detection methods (NIOX MINO). Results FENO was elevated in children with current asthma (32.2 ppb), wheeze (27.0 ppb), or rhinitis (23.2ppb) as compared to individuals without these respective symptoms/diagnoses (16.4 ppb to 16.6 ppb, p< 0.005 for all comparisons). Allergic sensitization to indoor allergens (cat, dog, dust mite) predicted higher levels of FENO, and explained one third of the variability of FENO. FENO levels were highest in children both sensitized and exposed to dust mite. Greater than 10 hours of weekday TV viewing was associated with a 0.64 log increase in FENO, after controlling indoor allergen exposure, BMI and allergic sensitization. Conclusion Allergen exposures and sedentary behavior (TV viewing/ video game playing), may increase airway inflammation, measured as FENO. PMID:21463890

Health assessment for Hagen Farm Site, Stoughton, Wisconsin, Region 5. CERCLIS No. WID980610059. Preliminary report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

Hagen Farm is listed on the National Priorities List. The site, in the township of Dunkirk, Dane County, Wisconsin, was found to be contaminating surrounding ground water in the early 1980's. The site was used as a dumpsite for industrial waste. The media of concern are ground water and on-site soil contamination. Soil contamination data are not available. The existing on-site data show ground water contamination at the monitoring-well sites. These contaminants at maximum levels include: xylenes, 27,000 ppb; ethylbenzene, 7000 ppb; toluene, 260 ppb; tetrahydrofuran, 56,000 ppb; chlorobenzene, 24 ppb. The Hagen Farm Site represents a public health concern.more » The ground water contamination has been clearly demonstrated, and continued private well use has been established. The ongoing use of the Sundby Sand and Gravel Well for industrial use and use in toilet facilities exposes workers to an unknown contamination.« less

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruchirawat, Mathuros; Navasumrit, Panida; Settachan, Daam

The effects of air pollution on human health are a great concern, particularly in big cities with severe traffic problems such as Bangkok, Thailand. In this study, exposure to genotoxic compounds in ambient air was studied by analysis of particle-associated polycyclic aromatic hydrocarbons (PAHs) and benzene through direct measurement of concentrations in air as well as through the use of different biomarkers of exposure: urinary 1-hydroxypyrene (1-OHP) for PAHs and urinary t,t-muconic acid (t,t-MA) for benzene. The study was conducted in various susceptible groups of the population with different occupations in 5 traffic-congested areas of Bangkok, as well as inmore » primary school children. The level of total PAHs on the main roads at various sites ranged from 7.10 to 83.04 ng/m{sup 3}, while benzene levels ranged from 16.35 to 49.25 ppb. In contrast, ambient levels in nearby temples, the control sites, ranged from 1.67 to 3.04 ng/m{sup 3} total PAHs and 10.16 to 16.25 ppb benzene. Street vendors selling clothes were exposed to 16.07 {+-} 1.64 ng/m{sup 3} total PAHs and 21.97 {+-} 1.50 ppb benzene, levels higher than in monks and nuns residing in nearby temples (5.34 {+-} 0.65 ng/m{sup 3} total PAHs and 13.69 {+-} 0.77 ppb benzene). Grilled-meat vendors in the same area were exposed to both total PAHs and benzene at even higher levels, possibly due to additional formation of PAHs during the grilling of meat (34.27 {+-} 7.02 ng/m{sup 3} total PAHs; 27.49 {+-} 2.72 ppb benzene). At the end of the workday, urinary 1-OHP levels in street vendors (0.12 and 0.15 {mu}mol/mol creatinine in clothes and grilled-meat vendors, respectively) were significantly higher than in controls (0.04 {mu}mol/mol creatinine; P < 0.01). Afternoon urinary t,t-MA levels in both groups of street vendors (0.12 mg/g creatinine) were also significantly higher than in controls (0.08 mg/g creatinine; P < 0.05). School children from two schools in Bangkok were exposed to total PAHs and benzene at levels of 6.70 {+-} 0.47 ng/m{sup 3} and 4.71 {+-} 0.25 ppb, respectively, higher than those to which children living outside the city were exposed (1.25 {+-} 0.24 ng/m{sup 3} total PAHs; 2.10 {+-} 0.16 ppb benzene). At the end of the school day, levels of urinary 1-OHP and t,t-MA were significantly higher (P < 0.001 and P < 0.01, respectively) in Bangkok school children (0.23 {mu}mol/mol creatinine and 0.27 mg/g creatinine, respectively) than in school children from outside Bangkok (0.10 {mu}mol/mol creatinine and 0.08 mg/g creatinine, respectively)« less

Pollen count and exhaled nitric oxide levels in a seasonal allergic rhinitis patient.

PubMed

Shirai, Toshihiro; Mochizuki, Eisuke; Asada, Kazuhiro; Suda, Takafumi

2014-09-01

The subject was a 52-year-old man with Japanese cedar pollinosis, which developed between February and May. He had no history of asthma and was an ex-smoker. He underwent fractional exhaled nitric oxide (FeNO) measurements twice a week from 2010 to 2012. The pollen counts in 2010 were the lowest during the last decade, and the FeNO level was less than 30 ppb for the whole year. In contrast, the mean pollen count in 2011 was very high and the patient's FeNO level rose to more than 100 ppb. The mean pollen count in 2012 was comparable with that of 2010; however, high counts were detected in April and May, and the FeNO level rose to 70 ppb during the latter stages of the pollen season. These results indicate that pollen counts should be taken into consideration during the interpretation of FeNO data in asthma or allergic rhinitis.

Sub-parts per million NO2 chemi-transistor sensors based on composite porous silicon/gold nanostructures prepared by metal-assisted etching.

PubMed

Sainato, Michela; Strambini, Lucanos Marsilio; Rella, Simona; Mazzotta, Elisabetta; Barillaro, Giuseppe

2015-04-08

Surface doping of nano/mesostructured materials with metal nanoparticles to promote and optimize chemi-transistor sensing performance represents the most advanced research trend in the field of solid-state chemical sensing. In spite of the promising results emerging from metal-doping of a number of nanostructured semiconductors, its applicability to silicon-based chemi-transistor sensors has been hindered so far by the difficulties in integrating the composite metal-silicon nanostructures using the complementary metal-oxide-semiconductor (CMOS) technology. Here we propose a facile and effective top-down method for the high-yield fabrication of chemi-transistor sensors making use of composite porous silicon/gold nanostructures (cSiAuNs) acting as sensing gate. In particular, we investigate the integration of cSiAuNs synthesized by metal-assisted etching (MAE), using gold nanoparticles (NPs) as catalyst, in solid-state junction-field-effect transistors (JFETs), aimed at the detection of NO2 down to 100 parts per billion (ppb). The chemi-transistor sensors, namely cSiAuJFETs, are CMOS compatible, operate at room temperature, and are reliable, sensitive, and fully recoverable for the detection of NO2 at concentrations between 100 and 500 ppb, up to 48 h of continuous operation.

Halimeter ppb Levels as the Predictor of Erosive Gastroesophageal Reflux Disease.

PubMed

Kim, Jung Gon; Kim, Yoon Jae; Yoo, Seung Hee; Lee, So Jung; Chung, Jun Won; Kim, Min Ho; Park, Dong Kyun; Hahm, Ki-Baik

2010-09-01

In a previous issue published in Gut and Liver, we found that erosive changes in the esophagogastroduodenal mucosa were strongly correlated with increased levels of volatile sulfur-containing compounds (VSC), suggesting that halitosis could be a symptom reflecting the erosive status of the upper gut mucosa. Together with other studies showing a possible association between halitosis and gastroesophageal reflux disease (GERD), under the premise that halitosis could be one of extraesophageal manifestations of erosive GERD (ERD), we investigated the significance of Halimeter ppb levels on ERD compared to non-erosive gastroesophageal reflux disease (NERD). Subjects were assigned to the NERD group if there was no evidence of esophageal erosive changes on endoscopy, despite reflux symptoms, and to the ERD group if they had GERD A, B, C, or D (according to the Los Angeles classification). The VSC levels were measured in all patients with either a Halimeter (before endoscopy) or by gas chromatography of the gastric juices aspirated during endoscopy. The VSC level differed significantly between the NERD and ERD groups (p<0.0001), suggesting that this can be used to discriminate between NERD and ERD. However, the VSC level did not differ significantly with the severity of GERD. Even though hiatal hernia and a body mass index of >24 kg/m(2) was significantly associated with ERD, there was no correlation with Halimeter ppb levels. Minimal-change lesions exhibited the highest VSC levels, signifying that minimal change lesions can be classified as ERD based on our finding that halimeter ppb levels were descrimitive of erosive change. Erosive changes in the esophageal mucosa were strongly associated with VSC levels, supporting the hypothesis that halitosis can be a potential biomarker for the discrimination between ERD and NERD, reflecting the presence of erosive change in the lower esophagogastric junction.

Hollow Waveguide Gas Sensor for Mid-Infrared Trace Gas Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, S; Young, C; Chan, J

2007-07-12

A hollow waveguide mid-infrared gas sensor operating from 1000 cm{sup -1} to 4000 cm{sup -1} has been developed, optimized, and its performance characterized by combining a FT-IR spectrometer with Ag/Ag-halide hollow core optical fibers. The hollow core waveguide simultaneously serves as a light guide and miniature gas cell. CH{sub 4} was used as test analyte during exponential dilution experiments for accurate determination of the achievable limit of detection (LOD). It is shown that the optimized integration of an optical gas sensor module with FT-IR spectroscopy provides trace sensitivity at the few hundreds of parts-per-billion concentration range (ppb, v/v) for CH{submore » 4}.« less

Chlorine bleaches - A significant long term source of mercury pollution

NASA Technical Reports Server (NTRS)

Siegel, S. M.; Eshleman, A.

1975-01-01

Products of industrial electrolysis of brine - NaOCl-based bleaches and NaOH - yielded 17 to 1290 ppb of Hg upon flameless atomic absorption analysis. Compared with current U.S. rejection value of 5 ppb for potable waters, the above levels seem sufficiently high to be a matter of environmental concern.

Chronic low-level arsenite exposure through drinking water increases blood pressure and promotes concentric left ventricular hypertrophy in female mice.

PubMed

Sanchez-Soria, Pablo; Broka, Derrick; Monks, Sarah L; Camenisch, Todd D

2012-04-01

Cardiovascular disease is the leading cause of death in the United States and worldwide. High incidence of cardiovascular diseases has been linked to populations with elevated arsenic content in their drinking water. Although this correlation has been established in many epidemiological studies, a lack of experimental models to study mechanisms of arsenic-related cardiovascular pathogenesis has limited our understanding of how arsenic exposure predisposes for development of hypertension and increased cardiovascular mortality. Our studies show that mice chronically exposed to drinking water containing 100 parts per billion (ppb) sodium arsenite for 22 weeks show an increase in both systolic and diastolic blood pressure. Echocardiographic analyses as well as histological assessment show concentric left ventricular hypertrophy, a primary cardiac manifestation of chronic hypertension. Live imaging by echocardiography shows a 43% increase in left ventricular mass in arsenic-treated animals. Relative wall thickness (RWT) was calculated showing that all the arsenic-exposed animals show an RWT greater than 0.45, indicating concentric hypertrophy. Importantly, left ventricular hypertrophy, although often associated with chronic hypertension, is an independent risk factor for cardiovascular-related mortalities. These results suggest that chronic low-level arsenite exposure promotes the development of hypertension and the comorbidity of concentric hypertrophy.

Explosives detection in the marine environment using UUV-modified immunosensor

NASA Astrophysics Data System (ADS)

Charles, Paul T.; Adams, André A.; Deschamps, Jeffrey R.; Veitch, Scott P.; Hanson, Alfred; Kusterbeck, Anne W.

2011-05-01

Port and harbor security has rapidly become a point of interest and concern with the emergence of new improvised explosive devices (IEDs). The ability to provide physical surveillance and identification of IEDs and unexploded ordnances (UXO) at these entry points has led to an increased effort in the development of unmanned underwater vehicles (UUVs) equipped with sensing devices. Traditional sensors used to identify and locate potential threats are side scan sonar/acoustic methods and magnetometers. At the Naval Research Laboratory (NRL), we have developed an immunosensor capable of detecting trace levels of explosives that has been integrated into a REMUS payload for use in the marine environment. Laboratory tests using a modified PMMA microfluidic device with immobilized monoclonal antibodies specific for TNT and RDX have been conducted yielding detection levels in the low parts-per-billion (ppb) range. New designs and engineered improvements in microfluidic devices, fluorescence signal probes, and UUV internal fluidic and optical components have been investigated and integrated into the unmanned underwater prototype. Results from laboratory and recent field demonstrations using the prototype UUV immunosensor will be discussed. The immunosensor in combination with acoustic and other sensors could serve as a complementary characterization tool for the detection of IEDs, UXOs and other potential chemical or biological threats.

LEVELS OF SYNTHETIC MUSKS COMPOUNDS IN ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

CORRELATION OF CHEMICAL MARKERS - NITRATE AND ...

EPA Pesticide Factsheets

Giving public water authorities another tool to monitor and measure levels of human waste contamination of waters simply and rapidly would enhance public protection. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. Subtask 3: To ap

Evaluation of ozone emissions and exposures from consumer products and home appliances.

PubMed

Zhang, Q; Jenkins, P L

2017-03-01

Ground-level ozone can cause serious adverse health effects and environmental impacts. This study measured ozone emissions and impacts on indoor ozone levels and associated exposures from 17 consumer products and home appliances that could emit ozone either intentionally or as a by-product of their functions. Nine products were found to emit measurable ozone, one up to 6230 ppb at a distance of 5 cm (2 inches). One use of these products increased room ozone concentrations by levels up to 106 ppb (mean, from an ozone laundry system) and personal exposure concentrations of the user by 12-424 ppb (mean). Multiple cycles of use of one fruit and vegetable washer increased personal exposure concentrations by an average of 2550 ppb, over 28 times higher than the level of the 1-h California Ambient Air Quality Standard for ozone (0.09 ppm). Ozone emission rates ranged from 1.6 mg/h for a refrigerator air purifier to 15.4 mg/h for a fruit and vegetable washer. The use of some products was estimated to contribute up to 87% of total daily exposures to ozone. The results show that the use of some products may result in potential health impacts. © 2016 The Authors. Indoor Air published by John Wiley & Sons Ltd.

Validation of the BetaStar® Advanced for Tetracyclines Test Kit for the Screening of Bulk Tank and Tanker Truck Milks for the Presence of Tetracycline Drug Residues.

PubMed

Ankrapp, David; Schaus, Benjamin; Clements, Lauren; Klein, Frank; Rice, Jennifer; Rejman, John

2018-05-09

A validation study was conducted for an immunochromatographic method (BetaStar ® Advanced for Tetracyclines) for detection of tetracycline antibiotic residues in raw, commingled bovine milk. The assay was demonstrated to detect tetracycline, chlortetracycline, and oxytetracycline at levels below the FDA tolerance levels but above the maximum sensitivity thresholds established by the National Conference on Interstate Milk Shipments. Results of internal and independent laboratory dose-response studies employing spiked samples were in agreement. All three drugs at the approximate 90/95% sensitivity levels were detected in milk collected from cows that had been treated with the specific drug. Selectivity of the assay was 100%, as no false-positive results were obtained in testing 881 control milk samples. Testing the estimated 90/95 sensitivity level for tetracycline (213 ppb), chlortetracycline (272 ppb), and oxytetracycline (180 ppb) and at 1000 ppb for each antibiotic resulted in 100% positive tests for each tetracycline. Results of ruggedness experiments established the operating parameter tolerances for the test. Results of cross-reactivity testing established that the assay detects certain other tetracycline drugs but does not cross-react with any of 32 drugs belonging to seven different drug classes. Abnormally high bacterial or somatic cell counts (SCC) in raw milk produced no assay interference.

Tissue PAH, blood cell and tissue changes following exposure to water accommodated fractions of crude oil in alligator gar, Atractosteus spatula.

PubMed

Omar-Ali, Ahmad; Hohn, Claudia; Allen, Peter J; Rodriguez, Jose; Petrie-Hanson, Lora

2015-07-01

Alligator gar Atractosteus spatula acclimated to brackish water (9 ppt) were exposed to water accommodated fraction oil loadings (surrogate to Macondo Deepwater Horizon, northern Gulf of Mexico) of 0.5 and 4.0 gm oil/L tank water for 48 h. The surrogate oil was approximately 98% alkanes and alkynes and 2% petroleum aromatic hydrocarbons. The 2% petroleum aromatic hydrocarbons were predominately naphthalene. After 48 h, naphthalene levels in fish liver exposed to 0.5 or 4 gm oil/L were 547.79 and 910.68 ppb, while muscle levels were 214.11 and 253.84 ppb. There was a significant decrease in peripheral blood lymphocyte numbers and a significant reduction of granulocytes in the kidney marrow of the same fish. Tissue changes included hepatocellular vacuolization and necrosis, necrotizing pancreatitis, renal eosinophilia, and splenic congestion. After 7 days recovery, liver naphthalene levels decreased to 43.59 and 43.20 ppb, while muscle levels decreased to 9.74, and 16.78 ppb for oil exposures of 0, 0.5 or 4 g/L. In peripheral blood and kidney marrow, blood cell counts returned to normal. The severity of liver and kidney lesions lessened after 7 days recovery in non-oiled water, but splenic congestion remained in all gar. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Generation of sub-ppb level vapor phase mixtures of biogenic volatile organic compounds from liquid phase standards and stepwise characterization of their volatilization properties by thermal desorption-gas chromatography-mass spectrometry.

PubMed

Iqbal, Mohammad Asif; Kim, Ki-Hyun

2014-12-19

In the analysis of biogenic volatile organic compounds (BVOCs) in ambient air, preparation of a sub-ppb level standard is an important factor. This task is very challenging as most BVOCs (e.g., monoterpenes) are highly volatile and reactive in nature. As a means to produce sub-ppb gaseous standards for BVOCs, we investigated the dynamic headspace (HS) extraction technique through which their vapors are generated from a liquid standard (mixture of 10 BVOCs: (1) α-pinene, (2) β-pinene, (3) 3-carene, (4) myrcene, (5) α-phellandrene, (6) α-terpinene, (7) R-limonene, (8) γ-terpinene, (9) p-cymene, and (10) Camphene) spiked into a chamber-style impinger. The quantification of BVOCs was made by collection on multiple-bed sorbent tubes (STs) and subsequent analysis by thermal desorption-gas chromatography-mass spectrometry (TD-GC-MS). Using this approach, sub-ppb level mixtures of gaseous BVOCs were generated at different sweep cycles. The mean concentrations of 10 BVOCs generated from the most stable conditions (i.e., in the third sweep cycle) varied in the range of 0.37±0.05 to 7.27±0.86ppb depending on the initial concentration of liquid standard spiked into the system. The reproducibility of the gaseous BVOCs generated as mixture standards, if expressed in terms of relative standard error using the concentration datasets acquired under stable conditions, ranged from 1.64 (α-phellandrene) to 9.67% (R-limonene). Copyright © 2014 Elsevier B.V. All rights reserved.

Application of Cavity Enhanced Absorption Spectroscopy to the Detection of Nitric Oxide, Carbonyl Sulphide, and Ethane—Breath Biomarkers of Serious Diseases

PubMed Central

Wojtas, Jacek

2015-01-01

The paper presents one of the laser absorption spectroscopy techniques as an effective tool for sensitive analysis of trace gas species in human breath. Characterization of nitric oxide, carbonyl sulphide and ethane, and the selection of their absorption lines are described. Experiments with some biomarkers showed that detection of pathogenic changes at the molecular level is possible using this technique. Thanks to cavity enhanced spectroscopy application, detection limits at the ppb-level and short measurements time (<3 s) were achieved. Absorption lines of reference samples of the selected volatile biomarkers were probed using a distributed feedback quantum cascade laser and a tunable laser system consisting of an optical parametric oscillator and difference frequency generator. Setup using the first source provided a detection limit of 30 ppb for nitric oxide and 250 ppb for carbonyl sulphide. During experiments employing a second laser, detection limits of 0.9 ppb and 0.3 ppb were obtained for carbonyl sulphide and ethane, respectively. The conducted experiments show that this type of diagnosis would significantly increase chances for effective therapy of some diseases. Additionally, it offers non-invasive and real time measurements, high sensitivity and selectivity as well as minimizing discomfort for patients. For that reason, such sensors can be used in screening for early detection of serious diseases. PMID:26091398

Application of Cavity Enhanced Absorption Spectroscopy to the Detection of Nitric Oxide, Carbonyl Sulphide, and Ethane--Breath Biomarkers of Serious Diseases.

PubMed

Wojtas, Jacek

2015-06-17

The paper presents one of the laser absorption spectroscopy techniques as an effective tool for sensitive analysis of trace gas species in human breath. Characterization of nitric oxide, carbonyl sulphide and ethane, and the selection of their absorption lines are described. Experiments with some biomarkers showed that detection of pathogenic changes at the molecular level is possible using this technique. Thanks to cavity enhanced spectroscopy application, detection limits at the ppb-level and short measurements time (<3 s) were achieved. Absorption lines of reference samples of the selected volatile biomarkers were probed using a distributed feedback quantum cascade laser and a tunable laser system consisting of an optical parametric oscillator and difference frequency generator. Setup using the first source provided a detection limit of 30 ppb for nitric oxide and 250 ppb for carbonyl sulphide. During experiments employing a second laser, detection limits of 0.9 ppb and 0.3 ppb were obtained for carbonyl sulphide and ethane, respectively. The conducted experiments show that this type of diagnosis would significantly increase chances for effective therapy of some diseases. Additionally, it offers non-invasive and real time measurements, high sensitivity and selectivity as well as minimizing discomfort for patients. For that reason, such sensors can be used in screening for early detection of serious diseases.

Risk profile and health vulnerability of female workers who pick cotton by organanochlorine pesticides from southern Punjab, Pakistan.

PubMed

Yasmeen, Humaira; Qadir, Abdul; Mumtaz, Mehvish; Eqani, Syed Ali Musstjab Akber Shah; Syed, Jabbir Hussain; Mahmood, Adeel; Jamil, Nadia; Nazar, Farva; Ali, Habib; Ahmad, Muhammad Shafiq; Tanveer, Zafar Iqbal; Zhang, Gan

2017-05-01

The present study was conducted to highlight the existing level of organochlorine-pesticides (OCPs) from human milk (n = 45) and blood serum (n = 40) of female workers who pick cotton in Khanewal District, southern Punjab, Pakistan. Source apportionment, congener-specific analysis, and risk surveillance of OCPs are reported from human milk and blood samples. Levels of OCPs in milk and blood serum samples ranged from 15.7 ppb to 538.3 ppb and from 16.4 ppb to 747.1 ppb, respectively, and were lower than previously published reports from other regions of the globe. Congener-specific analysis revealed that DDTs were predominant, followed by hexachlorocyclohexane, chlordane, and hexachlorobenzene. Calculated results for source apportionment analysis suggested that contamination load was a new input of DDTs as well as the historic use of lindane in the study area. Levels of OCPs in milk and blood serum were significantly (p < 0.05) correlated with age, time period of picking cotton, and number of children. Health risk revealed that female workers had risk of cancer among 1 per million; however, noncarcinogenic risks were not considerable. Environ Toxicol Chem 2017;36:1193-1201. © 2016 SETAC. © 2016 SETAC.

Measurements of lower carbonyls in Rome ambient air

NASA Astrophysics Data System (ADS)

Possanzini, M.; Di Palo, V.; Petricca, M.; Fratarcangeli, R.; Brocco, D.

Ambient levels and diurnal profiles of lower carbonyls were measured in Rome during selected days of summer 1994 and winter 1995. The most abundant carbonyls were formaldehyde (up to 27 ppb) followed by ethanal (< 17 ppb) and acetone (< 9 ppb). Gas-phase concentrations of other seven carbonyls were in the 0-3 ppb range. The results were discussed with respect to direct emissions and photochemical production. Using carbonyl/CO concentration ratios mobil source emissions of carbonyls were estimated for the urban area. The secondary production of C 1-C 3 aldehydes from reactions of alkenes with O 3 and OH radicals during the early morning hours of summer days was also calculated. The daytime pattern of carbonyls was found to be similar to that of toluene in wintertime and close to that of ozone in summer periods conductive to photochemical pollution episodes.

What controls the atmospheric methane seasonal variability over India?

NASA Astrophysics Data System (ADS)

Guha, Tania; Tiwari, Yogesh K.; Valsala, Vinu; Lin, Xin; Ramonet, Michel; Mahajan, Anoop; Datye, Amey; Kumar, K. Ravi

2018-02-01

Atmospheric CH4 observations from two ground-based stations within Indian subcontinent, namely, Sinhagad (SNG) and Cape Rama station (CRI) showed a strong seasonality with a minima (∼1800 ± 20 ppb) during southwest monsoon (SWM; i.e. June-September, JJAS) and a maxima (2000 ± 30 ppb) during northeast monsoon (NEM i.e. December-February, DJF) with a peak-to-peak seasonality close to 200 ppb. The Indian summer (winter) monsoon is characterized with strong southwesterly (northeasterly) winds of oceanic (land) origin at the surface level and strong easterly (westerly) jet streams aloft. The monsoon dynamics has pronounced impact on CH4 variability over India and is analyzed with winds, Lagrangian trajectories, and 3-dimentional distributions of CH4 simulated by a general circulation model. The model simulations suggest a consistent annual vertical structure (mean and sub-seasonal uncertainty) of CH4 over India with a stark contrast in concentration from summer to winter at surface levels (below 750 mb) in confirmation with what is identified by the ground-based observations. During SWM (NEM) the air with comparatively lower (higher) CH4 concentrations from southern (northern) hemisphere reduces the CH4 over India by 1814 ± 26 ppb (enhances by 1950 ± 51 ppb). The contribution of local fluxes to this seasonality appears to be albeit weak as the synthesized CH4 fluxes (from EDGAR dataset) of the Indian peninsula itself show a peak in summer and a dip in winter. Similar property of CH4 is also common to nearby oceanic region (i.e. over Arabian Sea, 1765 ± 10 ppb during summer) suggesting the role of monsoon dynamics as the controlling factor. Further the mixing and convection carries the CH4 to the upper atmosphere and advect inward or outward aloft according the seasonal monsoon dynamics.

Stability of selected volatile breath constituents in Tedlar, Kynar and Flexfilm sampling bags

PubMed Central

Mochalski, Paweł; King, Julian; Unterkofler, Karl; Amann, Anton

2016-01-01

The stability of 41 selected breath constituents in three types of polymer sampling bags, Tedlar, Kynar, and Flexfilm, was investigated using solid phase microextraction and gas chromatography mass spectrometry. The tested molecular species belong to different chemical classes (hydrocarbons, ketones, aldehydes, aromatics, sulphurs, esters, terpenes, etc.) and exhibit close-to-breath low ppb levels (3–12 ppb) with the exception of isoprene, acetone and acetonitrile (106 ppb, 760 ppb, 42 ppb respectively). Stability tests comprised the background emission of contaminants, recovery from dry samples, recovery from humid samples (RH 80% at 37 °C), influence of the bag’s filling degree, and reusability. Findings yield evidence of the superiority of Tedlar bags over remaining polymers in terms of background emission, species stability (up to 7 days for dry samples), and reusability. Recoveries of species under study suffered from the presence of high amounts of water (losses up to 10%). However, only heavier volatiles, with molecular masses higher than 90, exhibited more pronounced losses (20–40%). The sample size (the degree of bag filling) was found to be one of the most important factors affecting the sample integrity. To sum up, it is recommended to store breath samples in pre-conditioned Tedlar bags up to 6 hours at the maximum possible filling volume. Among the remaining films, Kynar can be considered as an alternative to Tedlar; however, higher losses of compounds should be expected even within the first hours of storage. Due to the high background emission Flexfilm is not suitable for sampling and storage of samples for analyses aiming at volatiles at a low ppb level. PMID:23323261

Ultrasensitive ppb-level NO2 gas sensor based on WO3 hollow nanosphers doped with Fe

NASA Astrophysics Data System (ADS)

Zhang, Ziyue; haq, Mahmood; Wen, Zhen; Ye, Zhizhen; Zhu, Liping

2018-03-01

WO3 mesoporous hollow nanospheres doped with Fe synthesized by a facile method have mesoporous hollow nanospherical like morphology, small grain size (10 nm), high crystalline quality and ultrahigh surface area (165 m2/g). XRD spectra and Raman spectra indicate the Fe doping leading to the smaller cell parameters as compared to pure WO3, and the slight distortion in the crystal lattice produces a number of defects, making it a better candidate for gas sensing. XPS analysis shows that Fe-doped WO3 mesoporous hollow nanospheres have more oxygen vacancies than pure WO3, which is beneficial to the adsorption of oxygen and NO2 and its surface reaction. The gas sensor based on Fe-WO3 exhibited excellent low ppb-level (10 ppb) NO2 detecting performance and outstanding selectivity.

Cadmium contamination in cereal-based diets and diet ingredients

DOE Office of Scientific and Technical Information (OSTI.GOV)

Siitonen, P.H.; Thompson, H.C. Jr.

1990-11-01

Cereal-based diet and/or diet ingredient cadmium levels were determined by graphite furnace AAS. Cadmium contamination was 88.3 and 447 ppb in two cereal-based diets, 44.6 and 48.9 ppb in two purified diets, and ranged from less than 1.1 to 22,900 ppb in the ingredients of one cereal-based diet. The major source of cadmium contamination was attributed to the calcium supplement used for diet formulation. Comparative analyses of two purified diet samples and one cereal-based diet by the National Institute of Standards and Technology (NIST, formerly the National Bureau of Standards) and the National Center for Toxicological Research (NCTR) gave virtuallymore » identical results for Cd. A comparative study of Cd levels determined by flame and furnace AAS was also made by the NCTR and the NIST.« less

Measurement of atmospheric ammonia at a dairy using differential optical absorption spectroscopy in the mid-ultraviolet

NASA Astrophysics Data System (ADS)

Mount, George H.; Rumburg, Brian; Havig, Jeff; Lamb, Brian; Westberg, Hal; Yonge, David; Johnson, Kristen; Kincaid, Ronald

Ammonia is the most abundant basic gas in the atmosphere, and after N 2 and N 2O is the most abundant nitrogen-containing specie (Seinfeld and Pandis, 1998. Atmospheric Chemistry and Physics: from air pollution to climate changes. Wiley, New York). Typical concentrations of ammonia in the boundary layer range from <1 part per billion by volume (ppbv) in the free continental troposphere to parts per million (ppmv) levels over animal waste lagoons and near animal stalls. Agricultural activities are the dominant global source of ammonia emissions and a major environmental concern. In the US, ≈85% of ammonia emissions come from livestock operations (EPA Trends, 1998. www.epa.gov/ttn/chief/trends98/chapter2.pdf). Dairy farms constitute a large fraction of the livestock inventory. Current estimates of ammonia emissions to the atmosphere are characterized by a high degree of uncertainty, and so it is very important to obtain better estimates of ammonia emissions. We are working at the Washington State University research dairy to quantify ammonia emissions and investigate the effects of various mitigation strategies on those emissions. We describe here a new instrument utilizing the differential optical absorption spectroscopy (DOAS) technique to measure ammonia in the mid-ultraviolet with a detectability limit of about 1 ppb. DOAS avoids many of the problems that have thwarted past ammonia concentration measurements. Initial results show concentrations in the barn/concrete yard areas in the tens of parts per million range, over the slurry lagoons of hundreds of parts per billion to low parts per million, and low parts per million levels after initial slurry applications onto pastureland. Future papers will report on emission fluxes from the various parts of the dairy and the results of mitigation strategies; we show here initial data results. For a recent review of ammonia volatilization from dairy farms, see Bussink and Oenema (Nutrient Cycling in Agroecosystems 51(1998) 19).

Pseudo-Patella Baja after total knee arthroplasty

PubMed Central

Kazemi, Seyyed Morteza; Besheli, Laleh Daftari; Eajazi, Alireza; Sajadi, Mohammad Reza Miniator; Okhovatpoor, Mohammad Ali; Zanganeh, Ramin Farhang; Minaei, Reza

2011-01-01

Summary Background One of the complications of total knee arthroplasty (TKA) which has not yet been directly addressed is pseudo-patella baja (PPB). True patella baja (PB) is present when the length of the patellar tendon becomes shorter. PPB is present when the patella tendon is not shortened, but the level of the joint line is elevated. This study was conducted to assess PPB in TKA. Material/Methods Sixty patients who had had a primary TKA at our center between 1995 and 2005 were included. The average follow-up was 27.5 months. The Knee Society Scoring (KSS), lateral knee x-rays and the Blackburne-Peel index were used for assessments. Results Out of the 60 patients, 43 (72%) demonstrated no joint line elevation or patellar tendon shortening (group A). Fifteen patients (25%) had joint line elevation (group B), and both PB and PPB were present in 2 (3%) patients (group C). KSS was lower in groups B and C compared with group A, but this difference was not statistically significant. The average range of motion (ROM) in group A was significantly higher compared with either group B or C, and patients in groups B and C showed significantly more severe pain compared with group A (P<0.001). Conclusions PPB is not an uncommon finding after TKA and is associated with a statistically significant decrease in ROM and an increase in pain. Furthermore, KSS in the PPB group was less than in patients without PPB, although the difference was not statistically meaningful. PMID:21525812

Assessment of fractionated exhaled nitric oxide as a biomarker for the treatment of eosinophilic esophagitis

PubMed Central

Nguyen-Traxler, Ann; Lee, Erika M.; Yip, Jason S.; Weinstock, Joel V.; Chan, Walter W.; Ngo, Peter; Weinstein, Barbara J.; Bonis, Peter A.

2012-01-01

Diagnosis of eosinophilic esophagitis (EoE) and determination of response to therapy is based on histological assessment of the esophagus, which requires upper endoscopy. In children, in whom a dietary approach is commonly used, multiple endoscopies are needed, because foods are eliminated and then gradually reintroduced. Ideally, noninvasive methods could supplement or replace upper endoscopy to facilitate management. Fractionated exhaled nitric oxide (FeNO) has been proposed as a useful measure for monitoring disease activity in studies of patients with eosinophil-predominant asthma and in other atopic disorders. Thus, we evaluated whether FeNO levels could be a useful biomarker to assess the response to therapy in EoE patients. This study was designed to determine whether there is a change in FeNO levels during treatment with topical corticosteroids and whether changes correlated with clinical response. This was a prospective, multicenter study that enrolled nonasthmatic patients with established EoE. FeNO levels and symptom scores were measured at baseline, biweekly during 6-week swallowed fluticasone treatment, and 4 weeks posttreatment. Twelve patients completed the trial. We found a statistically significant difference between median pre- and posttreatment FeNO levels [20.3 ppb (16.0–29.0 ppb) vs 17.6 ppb (11.7–27.3 ppb), p=0.009]. However, neither the pretreatment FeNO level, a change of FeNO level after 2 weeks of treatment, nor the FeNO level at the end of treatment confidently predicted a clinical or histological response. Although our findings suggest nitric oxide possibly has a physiological role in EoE, our observations do not support a role of FeNo determination for management of EoE. PMID:23394511

Study of Nox Levels At The Castellon Area (spain) By Means of Passive Samplers

NASA Astrophysics Data System (ADS)

Delgado, J. M.; Esteve, V.

Nitrogen oxides are emitted by mobile sources like traffic, heating engines and indus- tries. In the case of La Plana de Castellon area, the cities, the industrial area called El Serrallo (with its oil refinery and power plant), the tile factories and the main roads (A7-E15 and N-340), all they are the main pollutant focus of NOx. Those pollutants are precursors of tropospheric ozone formation. The aim of this work is the study of nitrogen oxides levels in La Plana de Castellon area, by means of passive samplers and stand relationships between NOx levels and ozone levels both measured with pas- sive samplers. The measurement campaign is made during summer, the higher pho- tochemical activity period (from May to September) in order to obtain the necessary data of NOx levels to make the relationship with measured ozone levels. Measuring campaing has been divided into sampling periods of one week. Twelve samples are collected each sampling period to cover an interest area of 1400 Km2, Two of these samples are laboratory blanks, four are situated at reference points (beside an auto- matic NOx sampler), one is situated at A7-E15 expressway, other at the main road N-340 and another one in a hard traffic road. The other three are placed in the main cities (Castellon and Benicassim). We employ Radielloo samplers developed by Dr. Cocheo at Fondazione Salvatore Maugeri. Samples located far from the main roads, at countryside show the lowest levels of NOx, lower than 10 ppb. Samples located at Castellon city show a difference between downtown and boundaries of about 33% higher at downtown, raising from 11 ppb to 14,5 ppb of NOx. The highest levels of NOx are measured at roads and their surroundings with medium levels of 14,3 ppb of NOx. Moreover, the sample located close to the expressway raises its level until 18 ppb of NOx, 53,4% higher than the media of all the samples measured. We would like to thank Dr. M. Wolfson(Harvard University), Dr. Carlos Felis (Conselleria de Medi Ambient) and Ms. C. Clemente for their contribution and work on this project as well as to Generalitat Valenciana for the FPI grant.

Improvement of Toluene Selectivity via the Application of an Ethanol Oxidizing Catalytic Cell Upstream of a YSZ-Based Sensor for Air Monitoring Applications

PubMed Central

Sato, Tomoaki; Breedon, Michael; Miura, Norio

2012-01-01

The sensing characteristics of a yttria-stabilized zirconia (YSZ)-based sensor utilizing a NiO sensing-electrode (SE) towards toluene (C7H8) and interfering gases (C3H6, H2, CO, NO2 and C2H5OH) were evaluated with a view to selective C7H8 monitoring in indoor atmospheres. The fabricated YSZ-based sensor showed preferential responses toward 480 ppb C2H5OH, rather than the target 50 ppb C7H8 at an operational temperature of 450 °C under humid conditions (RH ≃ 32%). To overcome this limitation, the catalytic activity of Cr2O3, SnO2, Fe2O3 and NiO powders were evaluated for their selective ethanol oxidation ability. Among these oxides, SnO2 was found to selectively oxidize C2H5OH, thus improving C7H8 selectivity. An inline pre-catalytic cell loaded with SnO2 powder was installed upstream of the YSZ-based sensor utilizing NiO-SE, which enabled the following excellent abilities by selectively catalyzing common interfering gases; sensitive ppb level detection of C7H8 lower than the established Japanese Guideline value; low interferences from 50 ppb C3H6, 500 ppb H2, 100 ppb CO, 40 ppb NO2, as well as 480 ppb C2H5OH. These operational characteristics are all indicative that the developed sensor may be suitable for real-time C7H8 concentration monitoring in indoor environments. PMID:22666053

Investigating ozone-induced decomposition of surface-bound permethrin for conditions in aircraft cabins.

PubMed

Coleman, B K; Wells, J R; Nazaroff, W W

2010-02-01

The reaction of ozone with permethrin can potentially form phosgene. Published evidence on ozone levels and permethrin surface concentrations in aircraft cabins indicated that significant phosgene formation might occur in this setting. A derivatization technique was developed to detect phosgene with a lower limit of detection of 2 ppb. Chamber experiments were conducted with permethrin-coated materials (glass, carpet, seat fabric, and plastic) exposed to ozone under cabin-relevant conditions (150 ppb O(3), 4.5/h air exchange rate, <1% relative humidity, 1700 ng/cm(2) of permethrin). Phosgene was not detected in these experiments. Reaction of ozone with permethrin appears to be hindered by the electron-withdrawing chlorine atoms adjacent to the double bond in permethrin. Experimental results indicate that the upper limit on the reaction probability of ozone with surface-bound permethrin is approximately 10(-7). Extrapolation by means of material-balance modeling indicates that the upper limit on the phosgene level in aircraft cabins resulting from this chemistry is approximately 1 microg/m(3) or approximately 0.3 ppb. It was thus determined that phosgene formation, if it occurs in aircraft cabins, is not likely to exceed relevant, health-based phosgene exposure guidelines. Phosgene formation from ozone-initiated oxidation of permethrin in the aircraft cabin environment, if it occurs, is estimated to generate levels below the California Office of Environmental Health Hazard Assessment acute reference exposure level of 4 microg/m(3) or approximately 1 ppb.

Effect of dietary vitamin E or selenium on prostaglandin dehydrogenase in hyperoxic rat lung

NASA Technical Reports Server (NTRS)

North, L. N.; Mathias, M. M.; Schatte, C. L.

1984-01-01

Weanling male rats were fed semipurified diets supplemented with 0, 60, or 600 IU/kg vitamin E or 0, 100, or 1000 ppb selenium. One group was injected daily with vitamin E at a rate equivalent to consumption of 60 IU/kg. Animals from all groups were sacrificed after exposure to normobaric oxygen or air for 48 h. Lung tissue was analyzed for the combined activity of prostaglandin dehydrogenase and reductase. Using the decline in enzyme activity as an indicator of susceptibility to oxygen poisoning, protection against hyperoxia was directly related to the level of vitamin E supplementation. Selenium supplemented at 100 ppb provided significant protection when compared to 0 ppb or 1000 ppb. The latter dose may have been marginally toxic. Thus dietary supplementation of vitamin E and selenium may influence the relative susceptibility of an animal to pulmonary oxygen poisoning.

Rapid determination of ampicillin in bovine milk by liquid chromatography with fluorescence detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ang, C.Y.W.; Luo, Wenhong

1997-01-01

A rapid and sensitive liquid chromatographic (LC) method was developed for the determination of ampicillin residues in raw bovine milk, processed skim milk, and pasteurized, homogenized whole milk with vitamin D. Milk samples were deproteinized with trichloroacetic acid (TCA) and acetonictrile. After centrifugation, the clear supernatant was reacted with formaldehyde and TCA under heat. The major fluorescent derivative of ampicillin was then determined by reversed-phase LC with fluorescence detection. Average recoveries of ampicillin fortified at 5, 10, and 20 ppb (ng/mL) were all >85% with coefficients of variation <10%. Limits of detection ranged from 0.31 to 0.51 ppb and limitsmore » of quantitation, from 0.66 to 1.2 ppb. After appropriate validation, this method should be suitable for rapid analysis of milk for ampicillin residues at the tolerance level of 10 ppb. 16 refs., 4 figs., 3 tabs.« less

Ion mobility analyzer - quadrupole mass spectrometer system design

NASA Astrophysics Data System (ADS)

Cuna, C.; Leuca, M.; Lupsa, N.; Mirel, V.; Bocos-Bintintan, V.; Cuna, Stela; Cosma, V.; Tusa, Florina

2009-08-01

Because of their extremely high sensitivity for chemicals with elevated electronegativity or high proton affinity the ion mobility analysers are ideal for the ultra-trace detection of toxic or explosive chemicals, most of these situated often at concentration levels of sub-ppb (parts-per-billion). Ion mobility spectrometers (IMS) can be used to identify illicit drugs or environmental pollutants. Since resolution of an IMS is relatively low, to achieve an accurate identification of target analyte it is recommended to couple the IMS with a quadrupole mass spectrometer (QMS) or a time of flight mass spectrometer, acquiring in this way confirmatory information. This coupling is made through a specific interface. In this paper, an experimental model of such a tandem instrument, IMS-QMS is described. Accomplishment of this general purpose will be done, overcoming a series of specific issues. This implies the solving, using innovative solutions, of a series of complex issues: ensuring the stability of the ions beam generated by ion source; transfer with a good efficiency of the ionic current from IMS analyser to QMS; and realization of a special electronic circuitry which will be able to detect both positive and negative ions.

Subminiaturization for ERAST instrumentation (Environmental Research Aircraft and Sensor Technology)

NASA Technical Reports Server (NTRS)

Madou, Marc; Lowenstein, Max; Wegener, Steven

1995-01-01

We are focusing on the Argus as an example to demonstrate our philosophy on miniaturization of airborne analytical instruments for the study of atmospheric chemistry. Argus is a two channel, tunable-diode laser absorption spectrometer developed at NASA for the measurement of nitrogen dioxide (N2O) (4.5 micrometers) and ammonia (CH3) (3.3 micrometers) at the 0.1 parts per billion (ppb) level from the Perseus aircraft platform at altitudes up to 30 km. Although Argus' mass is down to 23 kg from the 197 kg Atlas, its predecessor, our goal is to design a next-generation subminiaturized instrument weighing less than 1 kg, measuring a few cm(exp 3) and able to eliminate dewars for cooling. Current designs enable use to make a small,inexpensive, monolithic spectrometer without the required sensitivity range. Further work is on its way to increase sensitivity. We are continuing to zero-base the technical approach in terms of the specifications for the given instrument. We are establishing a check list of questions to hone into the best micromachining approach and to superpose on the answers insights in scaling laws and flexible engineering designs to enable more relaxed tolerances for the smallest of the components.

Exposure to hazardous volatile pollutants back diffusing from automobile exhaust systems.

PubMed

Rahman, Md Mahmudur; Kim, Ki-Hyun

2012-11-30

As back diffusion gases from automobiles are significant sources of in-vehicular pollution, we investigated eight automobiles, five for back diffusion (driving) measurements and three for reference conditions (non-driving). To characterize the back diffusion emission conditions, seven volatile organic compounds (VOC) and four carbonyl compounds (CCs) were measured along with dilution-to-threshold (D/T) ratio. The data obtained from back diffusion measurements were examined after having been divided into three subcategories: (i) driving and non-driving, (ii) with and without automobile upgrading (sealing the inner line), and (iii) differences in CO emission levels. Among the VOCs, the concentrations of toluene (T) was found to be the highest (range: 13.6-155 ppb), while benzene (0.19-1.47 ppb) was hardly distinguishable from its ambient levels. Other VOCs (xylene, trimethylbenzene, and styrene) were generally below <1 ppb. Unlike VOCs, the concentrations (ppb) of CCs were seen at fairly enhanced levels: 30.1-95 (formaldehyde), 34.6-87.2 (acetaldehyde), 4.56-34.7 (propionaldehyde), and 3.45-68.8 (butyraldehyde). The results of our study suggest that the back diffusion phenomenon, if occurring, can deteriorate in-vehicle air, especially with the most imminent health hazards from a compound such as formaldehyde in view of its exceedance pattern over common guidelines. Copyright © 2012 Elsevier B.V. All rights reserved.

Milk and Dairy Products Intake Is Associated with Low Levels of Lead (Pb) in Workers highly Exposed to the Metal.

PubMed

Gomes, Willian Robert; Devóz, Paula Pícoli; Araújo, Marília Ladeira; Batista, Bruno Lemos; Barbosa, Fernando; Barcelos, Gustavo Rafael Mazzaron

2017-07-01

Lead (Pb) is a toxic metal, frequently associated with occupational exposure, due to its widespread use in industry and several studies have shown high Pb levels in workers occupationally exposed to the metal. The aim of this study was to evaluate the influence of milk and dairy products (MDP) on Pb levels in blood (B-Pb), plasma (P-Pb), and urine (U-Pb), in workers from automotive battery industries in Brazil. The study included 237 male workers; information concerning diet and lifestyle were gathered through a questionnaire, and B-Pb, P-Pb, and U-Pb were determined by ICP-MS. Mean B-Pb, P-Pb, and U-Pb were 21 ± 12, 0.62 ± 0.73 μg/dL, and 39 ± 47 μg/g creatinine, respectively. Forty three percent of participants declared consuming ≤3 portions/week of MDP (classified as low-MDP intake), while 57% of individuals had >3portions/week of MDP (high-MDP intake). B-Pb and P-Pb were correlated with working time (r s  = 0.21; r s  = 0.20; p < 0.010). Multivariable linear regressions showed a significant influence of MDP intake on B-Pb (β = -0.10; p = 0.012) and P-Pb (β = -0.16; p < 0.010), while no significance was seen on U-Pb. Our results suggest that MDP consumption may modulate Pb levels in individuals highly exposed to the metal; these findings may be due to the Pb-Ca interactions, since the adverse effects of Pb are partially based on its interference with Ca metabolism and proper Ca supplementation may help to reduce the adverse health effects induced by Pb exposure.

Halitosis as a product of hepatic disease.

PubMed

Guglielmi, M; Beushausen, M; Feng, C; Beech, A; Baur, D

2014-09-01

This study evaluated halitosis in patients suffering from hepatic disease. Twenty-five patients (12 males and 13 females) aged between 16 and 73 years who had undergone treatment for liver disease were included in this study. Three halimeter recordings were performed to measure methyl mercarptan and hydrogen sulphite. Mean values were calculated and compared with normal values (75-120 ppb). The level of significance was set at P < .05. Results: Thirteen of the 25 subjects (52%) had normal Volatile Sulphur Compound (VSC) values (75-120 ppb). Twelve subjects (48%) recorded values ranging from 132 to 1112 ppb. There was no correlation between hepatic pathology and halitosis. Fifty-two percent of all subjects had poor oral hygiene, strongly correlated with high VSC values (P<0.05) whereas the remaining 48% with good hygiene had normal levels of VSC. Within the limitations of this study, high values of VSC were not associated with the presence of hepatic disease.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Safira, Nabila, E-mail: safira.nabila@ymail.com; Anggraeni, Tjandra, E-mail: tjandra@sith.itb.ac.id

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish themore » correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre–Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.« less

Analysis of lead concentration in forager stingless bees Trigona sp. (hymenoptera: Apidae) and propolis at Cilutung and Maribaya, West Java

NASA Astrophysics Data System (ADS)

Safira, Nabila; Anggraeni, Tjandra

2015-09-01

Several studies had shown that lead (Pb) in the environment could accumulate in bees, which in turn could affect the quality of the resulting product. In this study, forager stingless bees (Trigona sp.) and its product (propolis) collected from a stingless bees apiculture. This apiculture had two apiary sites which were distinguished by its environmental setting. Apiary site in Cilutung had a forest region environmental setting, while apiary site in Maribaya was located beside the main road. The objective of this study was to determine the extent of lead concentration in propolis originated from both apiary sites and establish the correlation between lead concentration in propolis and lead level in forager stingless bees. Forager bees and propolis samples were originated from 50 bees colonies (Cilutung) and 44 bees colonies (Maribaya). They were analyzed using AAS-GF (Atomic Absorption Spectrometre-Graphite Furnace) to determine the level of lead concentration. The results showed that the average level of lead in propolis originated from Cilutung (298.08±73.71 ppb) was lower than the average level of lead in forager bees which originated from Maribaya (330.64±156.34 ppb). However, these values did not show significant difference (p>0.05). There was no significant difference (p>0.05) between the average level of lead in forager bees which originated from Cilutung (118.08±30.46 ppb) and Maribaya (128.82±39.66 ppb). However, these values did not show significant difference (p>0.05). In conclusion, the average level of lead concentration in propolis in both sites had passed the maximum permission standard of lead for food in Indonesia. There was no correlation between lead concentration in propolis and forager stingless bees.

Development of an Automated Reader for Analysis and Storage of Personnel Dosimeter Badge Data

NASA Technical Reports Server (NTRS)

Meneghelli, B. J.; Hodge, T. R.; Robinson, L. J.; Lueck, D. E.

1997-01-01

The collection and archiving of data from personnel dosimeters has become increasingly important in light of the lowered threshold limit values (TLV) for hydrazine (HZ), monomethylhydrazine (MMH), and unsymmetrical dimethylhydrazine (UDMH). The American Conference of Government Industrial Hygienists (ACGIH) lowered the TLV from 100 parts per billion (ppb) to 10 ppb and has caused increased concern over long term exposures of personnel to trace levels of these hypergols and other potentially harmful chemicals. An automated system of reading the exposure levels of personnel dosimeters and storing exposure data for subsequent evaluation has been developed. The reading of personnel dosimeter badges for exposure lo potentially harmful vapor concentrations of hydrazines or other chemicals is performed visually by comparing the color developed by the badge with a calibrated color comparator. The result obtained using visual comparisons of the developed badge color with the comparator may vary widely from user to user. The automated badge reader takes the variability out of the dosimeter reading by accurately comparing the reflectance obtained from a colored spot on the badge with a reading on the same spot prior to any exposure to chemical vapors. The observed difference between the reflectance values is used as part of a calculation of the dose value for the badge based on a stored calibration curve. The badge reader also stores bar-code data unique to each badge, as well as bar-code information on the user, as part of the permanent badge record. The start and stop exposure times for each badge are recorded and can be used as part of the calculated concentration, in ppm, for each badge logged during a recording period. The badge reader is equipped with a number of badge holders, each of which is unique to a specific type of personnel dosimeter badge. This gives the reader maximum flexibility to allow for the reading of several different types of badges. Test results of the badge reader for several different types of personnel dosimeter badges are presented within the body of this paper.

Development of an Automated Reader for Analysis and Storage of Personnel Dosimeter Badge Data

NASA Technical Reports Server (NTRS)

Meneghelli, B. J.; Hodge, T. R.; Robinson, L. J.; Lueck, D. E.

1997-01-01

The collection and archiving of data from personnel dosimeters has become increasingly important in light of the lowered Threshold Limit Values (TLV) for HydraZine (HZ), MonoMethylHydrazine (MMH), and Unsymmetrical DiMethylHydrazine (UDMH). The American Conference of Government Industrial Hygienists (ACGIH) lowered the TLV from 100 parts per billion (ppb) to IO ppb and has caused increased concern over long term exposures of personnel to trace levels of these hypergols and other potentially harmful chemicals. An automated system of reading the exposure levels of personnel dosimeters and storing exposure data for subsequent evaluation has been developed. The reading of personnel dosimeter badges for exposure to potentially harmful vapor concentrations of hydrazines or other chemicals is performed visually by comparing the color developed by the badge with a calibrated color comparator. The result obtained using visual comparisons of the developed badge color with the comparator may vary widely from user to user. The automated badge reader takes the variability out of the dosimeter reading by accurately comparing the reflectance obtained from a colored spot on the badge with a reading on the same spot prior to any exposure to chemical vapors. The observed difference between the reflectance values is used as part of a calculation of the dose value for the badge based on a stored calibration curve. The badge reader also stores bar-code data unique to each badge, as well as bar-code information on the user, as part of the permanent badge record. The start and stop exposure times for each badge are recorded and can be used as part of the calculated concentration, in ppm, for each badge logged during a recording period. The badge reader is equipped with a number of badge holders, each of which is unique to a specific type of personnel dosimeter badge. This gives the reader maximum flexibility to allow for the reading of several different types of badges. Test results of the badge reader for several different types of personnel dosimeter badges are presented within the body of this paper.

Generation of sub-part-per-billion gaseous volatile organic compounds at ambient temperature by headspace diffusion of aqueous standards through decoupling between ideal and nonideal Henry's law behavior.

PubMed

Kim, Yong-Hyun; Kim, Ki-Hyun

2013-05-21

In the analysis of volatile organic compounds in air, the preparation of their gaseous standards at low (sub-ppb) concentration levels with high reliability is quite difficult. In this study, a simple dynamic headspace-based approach was evaluated as a means of generating vapor-phase volatile organic compounds from a liquid standard in an impinger at ambient temperature (25 °C). For a given sampling time, volatile organic compound vapor formed in the headspace was swept by bypassing the sweep gas through the impinger and collected four times in quick succession in separate sorbent tubes. In each experiment, a fresh liquid sample was used for each of the four sampling times (5, 10, 20, and 30 min) at a steady flow rate of 50 mL min(-1). The air-water partitioning at the most dynamic (earliest) sweeping stage was established initially in accord with ideal Henry's law, which was then followed by considerably reduced partitioning in a steady-state equilibrium (non-ideal Henry's law). The concentrations of gaseous volatile organic compounds, collected after the steady-state equilibrium, reached fairly constant values: for instance, the mole fraction of toluene measured at a sweeping interval of 10 and 30 min averaged 1.10 and 0.99 nmol mol(-1), respectively (after the initial 10 min sampling). In the second stage of our experiment, the effect of increasing the concentrations of liquid spiking standard was also examined by collecting sweep gas samples from two consecutive 10 min runs. The volatile organic compounds, collected in the first and second 10 min sweep gas samples, exhibited ideal and nonideal Henry's law behavior, respectively. From this observation, we established numerical relationships to predict the mole fraction (or mixing ratio) of each volatile organic compound in steady-state equilibrium in relation to the concentration of standard spiked into the system. This experimental approach can thus be used to produce sub-ppb levels of gaseous volatile organic compounds in a constant and predictable manner.

Quantification of toxins in a Cry1Ac + CpTI cotton cultivar and its potential effects on the honey bee Apis mellifera L.

PubMed

Han, Peng; Niu, Chang-Ying; Lei, Chao-Liang; Cui, Jin-Jie; Desneux, Nicolas

2010-11-01

Transgenic Cry1Ac + CpTI cotton (CCRI41) is increasingly planted throughout China. However, negative effects of this cultivar on the honey bee Apis mellifera L., the most important pollinator for cultivated ecosystem, remained poorly investigated. The objective of our study was to evaluate the potential side effects of transgenic Cry1Ac + CpTI pollen from cotton on young adult honey bees A. mellifera L. Two points emphasized the significance of our study: (1) A higher expression level of insecticidal protein Cry1Ac in pollen tissues was detected (when compared with previous reports). In particular, Cry1Ac protein was detected at 300 ± 4.52 ng g(-1) [part per billion (ppb)] in pollen collected in July, (2) Effects on chronic mortality and feeding behaviour in honey bees were evaluated using a no-choice dietary feeding protocol with treated pollen, which guarantee the highest exposure level to bees potentially occurring in natural conditions (worst case scenario). Tests were also conducted using imidacloprid-treated pollen at a concentration of 48 ppb as positive control for sublethal effect on feeding behaviour. Our results suggested that Cry1Ac + CpTI pollen carried no lethal risk for honey bees. However, during a 7-day oral exposure to the various treatments (transgenic, imidacloprid-treated and control), honey bee feeding behaviour was disturbed and bees consumed significantly less CCRI41 cotton pollen than in the control group in which bees were exposed to conventional cotton pollen. It may indicate an antifeedant effect of CCRI41 pollen on honey bees and thus bees may be at risk because of large areas are planted with transgenic Bt cotton in China. This is the first report suggesting a potential sublethal effect of CCRI41 cotton pollen on honey bees. The implications of the results are discussed in terms of risk assessment for bees as well as for directions of future work involving risk assessment of CCRI41 cotton.

Halimeter ppb Levels as the Predictor of Erosive Gastroesophageal Reflux Disease

PubMed Central

Kim, Jung Gon; Kim, Yoon Jae; Yoo, Seung Hee; Lee, So Jung; Chung, Jun Won; Kim, Min Ho; Park, Dong Kyun

2010-01-01

Background/Aims In a previous issue published in Gut and Liver, we found that erosive changes in the esophagogastroduodenal mucosa were strongly correlated with increased levels of volatile sulfur-containing compounds (VSC), suggesting that halitosis could be a symptom reflecting the erosive status of the upper gut mucosa. Together with other studies showing a possible association between halitosis and gastroesophageal reflux disease (GERD), under the premise that halitosis could be one of extraesophageal manifestations of erosive GERD (ERD), we investigated the significance of Halimeter ppb levels on ERD compared to non-erosive gastroesophageal reflux disease (NERD). Methods Subjects were assigned to the NERD group if there was no evidence of esophageal erosive changes on endoscopy, despite reflux symptoms, and to the ERD group if they had GERD A, B, C, or D (according to the Los Angeles classification). The VSC levels were measured in all patients with either a Halimeter (before endoscopy) or by gas chromatography of the gastric juices aspirated during endoscopy. Results The VSC level differed significantly between the NERD and ERD groups (p<0.0001), suggesting that this can be used to discriminate between NERD and ERD. However, the VSC level did not differ significantly with the severity of GERD. Even though hiatal hernia and a body mass index of >24 kg/m2 was significantly associated with ERD, there was no correlation with Halimeter ppb levels. Minimal-change lesions exhibited the highest VSC levels, signifying that minimal change lesions can be classified as ERD based on our finding that halimeter ppb levels were descrimitive of erosive change. Conclusions Erosive changes in the esophageal mucosa were strongly associated with VSC levels, supporting the hypothesis that halitosis can be a potential biomarker for the discrimination between ERD and NERD, reflecting the presence of erosive change in the lower esophagogastric junction. PMID:20981207

Direct observations of reactive atmospheric gases at ZOTTO station in the middle of Siberia as a base for large-scale modeling of atmospheric chemistry over Northern Eurasia

NASA Astrophysics Data System (ADS)

Skorokhod, Andrey; Belikov, Igor; Shtabkin, Yury; Moiseenko, Konstantin; Pankratova, Natalia; Vasileva, Anastasia; Rakitin, Vadim; Heimann, Martin

2015-04-01

Direct observations of atmospheric air composition are very important for a comprehensive understanding of atmospheric chemistry over Northern Eurasia and its variability and trends driven by abrupt climatic and ecosystem changes and anthropogenic pressure. Atmospheric air composition (including greenhouse gases and aerosols), its trends and variability is still insufficiently known for most of the nearly uninhabited areas of Northern Eurasia. This limits the accuracy of both global and regional models, which simulate climatological and ecosystem changes in this highly important region. From that point of view, the Zotino Tall Tower Observatory (ZOTTO) in the middle of Siberia (near 60N, 90E), launched in 2006 and governed by a scientific international consortium plays an important role providing unique information about concentrations of greenhouse and reactive trace gases, as well as aerosols. Simulations of surface concentrations of O3, NOx and CO performed by global chemical-transport model GEOS-Chem using up-to-date anthropogenic and biogenic emissions databases show very good agreement with values observed at ZOTTO in 2007-2012. Observed concentration of ozone has a pronounced seasonal variation with a clear peak in spring (40-45 ppbv in average and up to 80 ppbv in extreme cases) and minimum in winter. Average ozone level is about 20 ppbv that corresponds to the background conditions. Enhanced concentration in March-July is due to increased stratospheric-tropospheric exchange. In autumn and winter distribution of ozone is close to uniform. NOx concentration does not exceed 1 ppb that is typical for background areas but may vary by order and some more in few hours. Higher surface NOx(=NO+NO2) concentrations during day time generally correspond to higher ozone when NO/NO2 ratio indicates on clean or slightly polluted conditions. CO surface concentration has a vivid seasonal course and varies from about 100 ppb in summer till 150 ppb in winter. But during polluted cases which are quite regular CO may increase till 400 ppb and more. Most uncertainties are due to the wild fires, which are often in different regions of Siberia. Numerical assessment of climatically important natural and anthropogenic emission sources influencing observed CO and O3 concentrations and their seasonal variability was made using GEOS-Chem model. According to the results, during the cold period CO concentrations in the surface layer is largely driven atmospheric transport from anthropogenic sources in Western Europe (up to 20 ppb), south of European Russia (up to 35 ppb) and south-western Siberia (up to 28 ppb). During the warm season they are usually affected by air transport from eastern Siberia, where the main contribution to the CO emissions are biogenic VOC oxidation (up to 15 ppb) and wildfires (up to 12 ppb). Transport of pollutants from south-western Siberia can add about 2,5 ppb to the ozone summer level in Central Siberia. In wintertime this factor leads to a reduced surface ozone level by 2 ppb. The contribution of large remote emission sources (Europe) is estimated within 1 ppb. Generally the simulation results indicate a significant role of long-range air transport in addition to regional natural and anthropogenic sources of air pollution which determine the total balance of surface CO. These processes need to be considered in quantitative analyses of the factors that determine the long-term photochemical system evolution in the lower troposphere over the continental regions of Northern Eurasia. This work was supported by the Russian Scientific Fund under grant 14-47-00049.

Continuous determination of gaseous ammonia in the ambient atmosphere using fluorescence derivatization

NASA Astrophysics Data System (ADS)

Abbas, Rana; Tanner, Roger L.

A method for continuous determination of ambient ammonia levels employing o-phthalaldehyde fluorescence derivatization is described. A simplified Venturi scrubber and gas-liquid separator have been employed for reproducible measurements of ⩾ 0.1 ppb ambient ammonia with less than 2 min time resolution. The scrubbing efficiency of the ammonia gas collection system was determined to be 29 ± 1 %. During 4 d in August 1979 ambient ammonia levels at the Brookhaven National Laboratory site averaged about 1.5 ± 1.1 ppb during afternoon daylight hours.

Toward stand-off open-path measurements of NO and NO(2) in the sub-parts per million meter range using quantum cascade lasers (QCLs) in the intra-pulse absorption mode.

PubMed

Reidl-Leuthner, Christoph; Lendl, Bernhard

2013-12-01

Two thermoelectrically cooled mid-infrared distributed feedback quantum cascade lasers operated in pulsed mode have been used for the quasi-simultaneous determination of NO and NO2 in the sub-parts per million meter (sub-ppm-m) range. Using a beam splitter, the beams of the two lasers were combined and sent to a retro-reflector. The returned light was recorded with a thermoelectrically cooled mercury cadmium telluride detector with a rise time of 4 ns. Alternate operation of the lasers with pulse lengths of 300 ns and a repetition rate of 66 kHz allowed quasi-simultaneous measurements. During each pulse the laser temperature increased, causing a thermal chirp of the laser line of up to 1.3 cm(-1). These laser chirps were sufficient to scan rotational bands of NO centered at 1902 cm(-1) and NO2 located at 1632 cm(-1). In that way an absorption spectrum could be recorded from a single laser pulse. Currently achieved limits of detection are 600 parts per billion meter (ppb-m) for NO and 260 ppb-m for NO2 using signal averaging over 1 min. This work presents the first steps toward a portable stand-off, open-path instrument that uses thermoelectrically cooled detector and lasers.

Respiratory cancer risks among workers with glutaraldehyde exposure.

PubMed

Collins, James J; Burns, Carol; Spencer, Pam; Bodnar, Catherine M; Calhoun, Teresa

2006-02-01

Glutaraldehyde is a substance that represents a substantial portion of the human exposure to aldehydes in medicine and industry. Other aldehydes such as formaldehyde have been associated with increased cancer rates of the upper respiratory tract and leukemia. Our study is the only one, to our knowledge, to examine cancer rates among exposed glutaraldehyde workers. In an extended follow up using death certificates, we calculated standardized mortality ratios (SMRs) and 95% confidence intervals (CIs) for three cumulative exposure categories of glutaraldehyde. There were 99,730 person-years of observation among unexposed workers, 2934 person-years in the lower exposure category, < 0-100.0 parts per billion (ppb)-years, and 2805 person-years in the higher exposure category of 100.0+ ppb-years. For all respiratory cancers for these exposure categories, the SMRs were 0.9 (95% CI = 0.7-1.1), 1.0 (95% CI = 0.2-3.0), and 0.3 (95% CI = 0.0-1.5). No increasing trend of SMR with increasing exposure is observed for any cause of death examined. We observed no cancers of the nasal cavity and sinus (0.03 expected), nasopharynx (0.02 expected), or leukemia (0.6 expected) among all glutaraldehyde-exposed workers. Although our study findings should be tempered by the small size and the potentially low prevalence of smoking among glutaraldehyde workers, we found no increased rates of respiratory tract cancer or leukemia related to glutaraldehyde exposure.

Effects of ozone and acidic deposition on carbon allocation and mycorrhizal colonization of Pinus taeda L. seedlings

Treesearch

M.B. Adams; E.G. O' Neill

1991-01-01

Patterns of carbon allocation and mycorrhizal colonization were examined in loblolly pine seedlings from two half-sib families exposed to three ozone treatments (charcoal-filtered air, ambient air + 80 ppb 03 , and ambient air + 160 ppb 03) and three rain pH levels (5.2, 4.5, and 3.3) for 12 weeks in open-topped chambers in...

Asymptomatic prospective and retrospective cohorts with metal-on-metal hip arthroplasty indicate acquired lymphocyte reactivity varies with metal ion levels on a group basis

PubMed Central

Hallab, NJ; Caicedo, M; McAllister, K; Skipor, A; Amstutz, H; Jacobs, JJ

2012-01-01

Some tissues from metal-on-metal (MoM) hip arthroplasty revisions have shown evidence of adaptive-immune reactivity (i.e., excessive peri-implant lymphocyte infiltration/activation). We hypothesized that, prior to symptoms, some people with MoM hip arthroplasty will develop quantifiable metal-induced lymphocyte reactivity responses related to peripheral metal ion levels. We tested 3 cohorts (Group-1: n=21 prospective longitudinal MoM hip arthroplasty; Group-2: n=17 retrospective MoM hip arthroplasty; and Group-3: n=20 controls without implants). We compared implant position, metal-ion release, and immuno-reactivity. MoM cohorts had elevated (p<0.01) amounts of serum Co and Cr compared to controls as early as 3 mos post-op (Group-1:1.2ppb-Co, 1.5ppb-Cr; Group-2: 3.4ppb-Co,, 5.4ppb-Cr; Group-3: 0.01ppb-Co, 0.1ppb-Cr). However, only after 1 to 4 yrs post-op did 56% of Group-1 develop metal-reactivity (vs. 5%pre-op, metal-LTT, SI>2), compared with 76% of Group-2 and 15% of Group-3 controls (patch testing was a poor diagnostic indicator with only 1/21 Group-1 positive). Higher cup-abduction angles (50° vs. 40°) in Group-1 were associated with higher serum Cr (p<0.07). However, sub-optimal cup-anteversion angles (9° vs. 20°) had higher serum Co (p<0.08). Serum Cr and Co were significantly elevated in reactive vs. non-reactive Group-1 participants (p<0.04). CD4+CD69+ T-helper lymphocytes (but not CD8+) and IL-1β, IL-12 and IL-6 cytokines were all significantly elevated in metal-reactive vs. non-reactive Group-1 participants. Our results showed that lymphocyte reactivity to metals can develop within the first 1 to 4 years after MoM arthroplasty in asymptomatic patients and lags increases in metal ion levels. This increased metal reactivity was more prevalent in those individuals with extreme cup angles and higher amounts of circulating metal. PMID:22941579

Room temperature ppb level Cl2 sensing using sulphonated copper phthalocyanine films.

PubMed

Kumar, Arvind; Singh, A; Debnath, A K; Samanta, S; Aswal, D K; Gupta, S K; Yakhmi, J V

2010-09-15

We present room temperature chemiresistive gas sensing characteristics of drop casted sulphonated copper phthalocyanine (CuTsPc) films. It has been demonstrated that these films are highly selective to Cl(2) and the sensitivity in the 5-2000 ppb range varies linearly between 65 and 625%. However, for concentrations >or=2000 ppb, the response becomes irreversible, which is found to be due to the chemical bond formation between Cl(2) and SO(3)Na group of CuTsPc films. The X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) data confirms the oxidation of SO(3)Na group by Cl(2) gas. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Elemental distribution in seaweed, Gelidium abbottiorum along the KwaZulu-Natal Coastline, South Africa.

PubMed

Misheer, Natasha; Kindness, Andrew; Jonnalagadda, Sreekanth B

2006-01-01

The total concentrations of 7 selected metals, namely manganese, iron, zinc, titanium, boron, arsenic and mercury, were monitored for one annual cycle covering four seasons in the seaweed, Gelidium abbottiorum, at four sampling sites at Zinkwasi, Ballito, Treasure beach and Park Rynie along the South-East coastline of KwaZulu-Natal, South Africa to assess the current status of the marine environment. Inductively Coupled Plasma Optical Emission Spectrophotometry, Mercury Cold Vapour AAS, and Hydride Generation AAS were used for the determination of metal concentrations. Mn concentrations were particularly high in the G. abbottiorum species, followed by Fe, As and B concentrations which were in the 3-8 ppm range. Ti and Zn were in the 100-400 ppb range, while Hg was low and below 100 ppb. A typical sample of G. abbottiorum at Treasure beach, a site close to Durban metropolis in winter had Mn (8.6 ppm), Fe (4.6 ppm), As (5.6 ppm), B (3.0 ppm), Ti (420 ppb), Zn (167 ppb) and Hg (7.5 ppb). All metals recorded a decrease in concentrations from winter to spring with the exception of Hg. The Hg levels increased considerably from winter to spring.

Aqueous nitrite ion determination by selective reduction and gas phase nitric oxide chemiluminescence

NASA Technical Reports Server (NTRS)

Dunham, A. J.; Barkley, R. M.; Sievers, R. E.; Clarkson, T. W. (Principal Investigator)

1995-01-01

An improved method of flow injection analysis for aqueous nitrite ion exploits the sensitivity and selectivity of the nitric oxide (NO) chemilluminescence detector. Trace analysis of nitrite ion in a small sample (5-160 microL) is accomplished by conversion of nitrite ion to NO by aqueous iodide in acid. The resulting NO is transported to the gas phase through a semipermeable membrane and subsequently detected by monitoring the photoemission of the reaction between NO and ozone (O3). Chemiluminescence detection is selective for measurement of NO, and, since the detection occurs in the gas-phase, neither sample coloration nor turbidity interfere. The detection limit for a 100-microL sample is 0.04 ppb of nitrite ion. The precision at the 10 ppb level is 2% relative standard deviation, and 60-180 samples can be analyzed per hour. Samples of human saliva and food extracts were analyzed; the results from a standard colorimetric measurement are compared with those from the new chemiluminescence method in order to further validate the latter method. A high degree of selectivity is obtained due to the three discriminating steps in the process: (1) the nitrite ion to NO conversion conditions are virtually specific for nitrite ion, (2) only volatile products of the conversion will be swept to the gas phase (avoiding turbidity or color in spectrophotometric methods), and (3) the NO chemiluminescence detector selectively detects the emission from the NO + O3 reaction. The method is free of interferences, offers detection limits of low parts per billion of nitrite ion, and allows the analysis of up to 180 microL-sized samples per hour, with little sample preparation and no chromatographic separation. Much smaller samples can be analyzed by this method than in previously reported batch analysis methods, which typically require 5 mL or more of sample and often need chromatographic separations as well.

Spontaneous pregnancy loss in humans and exposure to arsenic in drinking water.

PubMed

Bloom, Michael S; Fitzgerald, Edward F; Kim, Keewan; Neamtiu, Iulia; Gurzau, Eugen S

2010-11-01

Maternal exposure to high concentrations of inorganic arsenic (iAs) in naturally contaminated drinking groundwater sources has been associated with an increased risk for the spontaneous loss of clinically recognized pregnancies in several epidemiologic studies. Whereas a large worldwide population depends on drinking groundwater sources with high levels of iAs contamination, in quantities exceeding 10 parts per billion (ppb), an even larger population is likely to be exposed to mild-moderate drinking groundwater iAs contamination, in quantities <10ppb. Only a single epidemiologic study to date has considered spontaneous pregnancy loss in association with consumption of drinking water with mild-moderate iAs contamination; the vast majority of published studies of spontaneous loss addressed populations with substantial exposure. The aim of this review is to evaluate the published literature to assess the plausibility for a causal association between exposure to iAs-contaminated drinking water and the spontaneous loss of clinically recognized pregnancy. In spite of numerous methodologic limitations resulting from circumstance or design, a consistent pattern of increased risk for loss is suggested by the epidemiologic literature. Moreover, these study results are corroborated by a large number of experimental studies, albeit usually conducted at concentrations exceeding that to which humans are exposed via contaminated drinking water. In this review, we discuss sources of human iAs exposure, highlight several experimental studies pertinent to a possible causal link between iAs and spontaneous pregnancy loss in humans, and provide a critical review of published epidemiologic studies of pregnancy loss and drinking water iAs exposures, and their limitations. Based on a review of the published literature, we recommend the future conduct of a two-stage comprehensive prospective study of low-moderate iAs drinking water exposure and spontaneous pregnancy loss. Copyright © 2010 Elsevier GmbH. All rights reserved.

Highly Efficient Luminescent Metal-Organic Framework for the Simultaneous Detection and Removal of Heavy Metals from Water.

PubMed

Rudd, Nathan D; Wang, Hao; Fuentes-Fernandez, Erika M A; Teat, Simon J; Chen, Feng; Hall, Gene; Chabal, Yves J; Li, Jing

2016-11-09

We have designed and synthesized an isoreticular series of luminescent metal-organic frameworks (LMOFs) by incorporating a strongly emissive molecular fluorophore and functionally diverse colinkers into Zn-based structures. The three-dimensional porous networks of LMOF-261, -262, and -263 represent a unique/new type of nets, classified as a 2-nodal, (4,4)-c net (mot-e type) with 4-fold, class IIIa interpenetration. All compounds crystallize in a body-centered tetragonal crystal system (space group I4 1 /a). A systematic study has been implemented to analyze their interactions with heavy metals. LMOF-263 exhibits impressive water stability, high porosity, and strong luminescence, making it an excellent candidate as a fluorescent chemical sensor and adsorbent for aqueous contaminants. It is extremely responsive to toxic heavy metals at a parts per billion level (3.3 ppb Hg 2+ , 19.7 ppb Pb 2+ ) and demonstrates high selectivity for heavy metals over light metals, with detection ratios of 167.4 and 209.5 for Hg 2+ /Ca 2+ and Hg 2+ /Mg 2+ , respectively. Mixed-metal adsorption experiments also show that LMOF-263 selectively adsorbs Hg 2+ over other heavy metal ions in addition to light metals. The Pb 2+ K SV value for LMOF-263 (55,017 M -1 ) is the highest among LMOFs reported to date, and the Hg 2+ K SV value is the second highest (459,446 M -1 ). LMOF-263 exhibits a maximum adsorption capacity of 380 mg Hg 2+ /g. The Hg 2+ adsorption process follows pseudo-second-order kinetics, removing 99.1% of the metal within 30 min. An in situ XPS study provides insight to help understand the interaction mechanism between Hg 2+ and LMOF-263. No other MOFs have demonstrated such a high performance in both the detection and the capture of Hg 2+ from aqueous solution.

Effects of in Utero Exposure to Arsenic during the Second Half of Gestation on Reproductive End Points and Metabolic Parameters in Female CD-1 Mice

PubMed Central

Rodriguez, Karina F.; Ungewitter, Erica K.; Crespo-Mejias, Yasmin; Liu, Chang; Nicol, Barbara; Kissling, Grace E.; Yao, Humphrey Hung-Chang

2015-01-01

Background Mice exposed to high levels of arsenic in utero have increased susceptibility to tumors such as hepatic and pulmonary carcinomas when they reach adulthood. However, the effects of in utero arsenic exposure on general physiological functions such as reproduction and metabolism remain unclear. Objectives We evaluated the effects of in utero exposure to inorganic arsenic at the U.S. Environmental Protection Agency (EPA) drinking water standard (10 ppb) and at tumor-inducing levels (42.5 ppm) on reproductive end points and metabolic parameters when the exposed females reached adulthood. Methods Pregnant CD-1 mice were exposed to sodium arsenite [none (control), 10 ppb, or 42.5 ppm] in drinking water from gestational day 10 to birth, the window of organ formation. At birth, exposed offspring were fostered to unexposed dams. We examined reproductive end points (age at vaginal opening, reproductive hormone levels, estrous cyclicity, and fertility) and metabolic parameters (body weight changes, hormone levels, body fat content, and glucose tolerance) in the exposed females when they reached adulthood. Results Arsenic-exposed females (10 ppb and 42.5 ppm) exhibited early onset of vaginal opening. Fertility was not affected when females were exposed to the 10-ppb dose. However, the number of litters per female was decreased in females exposed to 42.5 ppm of arsenic in utero. In both 10-ppb and 42.5-ppm groups, arsenic-exposed females had significantly greater body weight gain, body fat content, and glucose intolerance. Conclusion Our findings revealed unexpected effects of in utero exposure to arsenic: exposure to both a human-relevant low dose and a tumor-inducing level led to early onset of vaginal opening and to obesity in female CD-1 mice. Citation Rodriguez KF, Ungewitter EK, Crespo-Mejias Y, Liu C, Nicol B, Kissling GE, Yao HH. 2016. Effects of in utero exposure to arsenic during the second half of gestation on reproductive end points and metabolic parameters in female CD-1 mice. Environ Health Perspect 124:336–343; http://dx.doi.org/10.1289/ehp.1509703 PMID:26295903

Embryonic-only arsenic exposure alters skeletal muscle satellite cell function in killifish (Fundulus heteroclitus).

PubMed

Szymkowicz, Dana B; Schwendinger, Katey L; Tatnall, Caroline M; Swetenburg, John R; Bain, Lisa J

2018-05-01

Arsenic is a contaminant found worldwide in drinking water and food. Epidemiological studies have correlated arsenic exposure with reduced weight gain and improper muscular development, while in vitro studies show that arsenic exposure impairs myogenic differentiation. The purpose of this study was to use Fundulus heteroclitus or killifish as a model organism to determine if embryonic-only arsenic exposure permanently reduces the number or function of muscle satellite cells. Killifish embryos were exposed to 0, 50, 200, or 800 ppb arsenite (As III ) until hatching, and then juvenile fish were raised in clean water. At 28, 40, and 52 weeks after hatching, skeletal muscle injuries were induced by injecting cardiotoxin into the trunk of the fish just posterior to the dorsal fin. Muscle sections were collected at 0, 3 and 10 days post-injury. Collagen levels were used to assess muscle tissue damage and recovery, while levels of proliferating cell nuclear antigen (PCNA) and myogenin were quantified to compare proliferating cells and newly formed myoblasts. At 28 weeks of age, baseline collagen levels were 105% and 112% greater in 200 and 800 ppb groups, respectively, and at 52 weeks of age, were 58% higher than controls in the 200 ppb fish. After cardiotoxin injury, collagen levels tend to increase to a greater extent and take longer to resolve in the arsenic exposed fish. The number of baseline PCNA(+) cells were 48-216% greater in 800 ppb exposed fish compared to controls, depending on the week examined. However, following cardiotoxin injury, PCNA is reduced at 28 weeks in 200 and 800 ppb fish at day 3 during the recovery period. By 52 weeks, there are significant reductions in PCNA in all exposure groups at day 3 of the recovery period. Based on these results, embryonic arsenic exposure increases baseline collagen levels and PCNA(+) cells in skeletal muscle. However, when these fish are challenged with a muscle injury, the proliferation and differentiation of satellite cells into myogenic precursors is impaired and instead, the fish appear to be favoring a fibrotic resolution to the injury. Copyright © 2018 Elsevier B.V. All rights reserved.

Simultaneous Determination of Residue from 58 Pesticides in the Wheat Flour Consumed in Tehran, Iran by GC/MS

PubMed Central

Rezaei, Mohammad; Shariatifar, Nabi; Shoeibi, Shahram; Amir Ahmadi, Maryam; Jahed Khaniki, Gholamreza

2017-01-01

Food safety has a direct impact on human health and as such is a growing concern worldwide. Presence of harmful pesticide residue in food is a serious cause for concern among consumers so it is important to monitor levels of pesticides in foods. The aim of this study was simultaneous determination of concentrations of 58 pesticides in 40 wheat flour samples collected from Tehran market in January, 2014. The city under study (Tehran) was divided into five districts and samples were collected independently from each district and sourced from different bakeries (n=40). A gas chromatography-mass spectrometry single quadrupole selected ion monitoring «GC/MS-SQ-SIM» method was used to quantify residue of 58 pesticides in the wheat flour samples. Four of the 40 samples showed contamination with Malathion (2 samples: 50.96 ± 11.38 and 62.088 ± 11.38 ppb) and 2, 4-DDE (2 samples: 19.88±15.24 and 13.7 ± 15.24 ppb). that had levels below MRLs of these pesticides in Iran. Averages of recovery of pesticides at 6 concentration levels were in the range of 81.61-118.41%. The method was proven as repeatable with RSDr in the range of 6.5-29.45% for all concentration levels. The limit of quantification for 37 of the tested pesticides was calculated as 15 ppb and for the other 21 tested pesticides, the concentration was 25 ppb. In summary, results of these tests suggested that the wheat flour consumed in Tehran, was within safety limits in terms of levels of pesticide residues. PMID:29201093

Mixing Heights and Three-Dimensional Ozone Structure Observed by Airborne Lidar During the 2006 Texas Air Quality Study

NASA Astrophysics Data System (ADS)

Hardesty, R. M.; Senff, C. J.; Alvarez, R. J.; Banta, R. M.; Sandberg, S. P.; Weickmann, A. M.; Darby, L. S.

2007-12-01

A new all solid state ozone lidar was deployed on a NOAA Twin Otter to study boundary layer ozone and aerosol, mostly around Houston, during the 2006 Texas Air Quality Study. The new instrument transmits high pulse-rate, low pulse-energy light at 3 wavelengths in the ultraviolet to obtain ozone profiles with 500 m horizontal resolution and 90 m vertical resolution. During the Texas field study, 20 research flights resulted in nearly 70 hours of ozone measurements during the period from August 1 to September 15. Science objectives included characterization of background ozone levels over rural areas near Houston and Dallas and variability and structure of the boundary layer over different surface types, including urban, wooded, and agricultural land surface areas as well as over Galveston Bay and the Gulf of Mexico. A histogram of all boundary layer ozone concentration measurements showed a bimodal distribution with modes at 45 ppb and 70 ppb. The lower mode correlated with southerly flow, when relatively clean air was transported onshore into the Houston area. Segmenting the observations during southerly flow by region, including the Gulf of Mexico, land within about 55 km from the coast, and further inland indicated that background levels increased by about 10 ppb as air was transported onshore. During the latter part of the experiment, as more pollution was imported into the Houston region, background levels rose to nearly 80 ppb in regions N of Houston. Two flights aimed at observing import of ozone into Texas from the east showed that ozone concentrations increased and boundary layer depths deepened upwind of Houston between September 4 and September 8. Background levels rose by more than 10 ppb over this period. In addition to ozone measurements, we also estimated boundary layer height based on maximum gradient in observed backscatter. The technique worked well when the layer topped by the strongest gradient extends down to the surface. Investigation of the correlation between ozone levels and mixing layer heights both within and external to the Houston urban plume showed a variety of relationships, depending on, e.g., wind direction and occurrence of a bay/gulf breeze. On a day-to-day basis, higher ozone levels were weakly correlated with deeper mixing levels - this was likely due to advection of the urban heat island downwind with the high-ozone urban plume.

Preliminary Public Health, Environmental Risk, and Data Requirements Assessment for the Herbicide Orange Storage Site at Johnston Island

DTIC Science & Technology

1991-10-01

an average concentration of 0.8 ppb. 2,4-D in surface soil ranges from 2.5 ppb to 281,330 ppb with an average of 49,986 ppb. 2,4,5-T in surface soil...ranges from 53 ppb to 237,155 ppb, with an average of 48,914 ppb. Approximately 25% of the site was sampled for subsurface TCDD in the 3-7 inch layer of...subsurface soil. Values ranged from 0.02 ppb to 207 ppb, with an average reading of 15 ppb. Approximately 2% of the site was sampled for subsurface

Surface-Functionalized Electrospun Titania Nanofibers for the Scavenging and Recycling of Precious Metal Ions.

PubMed

Dai, Yunqian; Formo, Eric; Li, Haoxuan; Xue, Jiajia; Xia, Younan

2016-10-20

Precious metals are widely used as catalysts in industry. It is of critical importance to keep the precious metal ions leached from catalysts at a level below one part per million (ppm) in the final products and to recycle the expensive precious metals. Here we demonstrate a simple and effective method for scavenging precious metal ions from an aqueous solution and thereby reduce their concentrations down to the parts per billion (ppb) level. The key component is a filtration membrane comprised of titania (TiO 2 ) nanofibers whose surface has been functionalized with a silane bearing amino or thiol group. When operated under continuous flow at a rate of 1 mL min -1 and at room temperature, up to 99.95 % of the Pd 2+ ions could be removed from a stock solution with an initial concentration of 100 ppm. This work offers a viable strategy not only for the removal of precious metal ions but also for recovering and further recycling them for use as catalysts. For example, the captured Pd 2+ ions could be converted to nanoparticles and used as catalysts for organic reactions such as Suzuki coupling in a continuous flow reactor. This system can be potentially applied to pharmaceutical industry and waste stream treatment. © 2016 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Multi-channeled single chain variable fragment (scFv) based microfluidic device for explosives detection.

PubMed

Charles, Paul T; Davis, Jasmine; Adams, André A; Anderson, George P; Liu, Jinny L; Deschamps, Jeffrey R; Kusterbeck, Anne W

2015-11-01

The development of explosives detection technologies has increased significantly over the years as environmental and national security agencies implement tighter pollution control measures and methods for improving homeland security. 2, 4, 6-Trinitrotoluene (TNT), known primarily as a component in munitions, has been targeted for both its toxicity and carcinogenic properties that if present at high concentrations can be a detriment to both humans, marine and plant ecosystems. Enabling end users with environmental detection and monitoring systems capable of providing real-time, qualitative and quantitative chemical analysis of these toxic compounds would be extremely beneficial. Reported herein is the development of a multi-channeled microfluidic device immobilized with single chain fragment variable (scFv) recombinant proteins specific for the explosive, TNT. Fluorescence displacement immunoassays performed under constant flow demonstrated trace level sensitivity and specificity for TNT. The utility of three multi-channeled devices immobilized with either (1) scFv recombinant protein, (2) biotinylated-scFv (bt-scFv) and (3) monoclonal anti-TNT (whole IgG molecule) were investigated and compared. Fluorescence dose response curves, crossreactivity measurements and limits of detection (LOD) for TNT were determined. Fluorescence displacement immunoassays for TNT in natural seawater demonstrated detection limits at sub-parts-per-billion levels (0.5 ppb) utilizing the microfluidic device with immobilized bt-scFv. Published by Elsevier B.V.

CHEMICAL MARKERS OF HUMAN WASTE ...

EPA Pesticide Factsheets

Giving public water authorities a tool to monitor and measure levels of human waste contamination of waters simply and rapidly would enhance public protection. This methodology, using both urobilin and azithromycin (or any other human-use pharmaceutical) could be used to give public water authorities a rapid (24- hrs) and definitive method for measuring human waste contamination The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subco

LEVELS OF SYNTHETIC MUSK COMPOUNDS IN ...

EPA Pesticide Factsheets

To be presented is an overview of the chemistry, the monitoring methodology, and the statistical evaluation of concentrations obtained from the analysis of a suite of compounds (e.g., Galaxolide®, musk xylene, and amino musk xylene) in an aquatic ecological site. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles

CHEMICAL MARKERS OF HUMAN WASTE ...

EPA Pesticide Factsheets

Giving public water authorities a tool to monitor and measure levels of human waste contamination of waters simply and rapidly would enhance public protection. This methodology, using both urobilin and azithromycin (or any other human-use pharmaceutical) could be used to give public water authorities a rapid (24- hrs) and definitive method for measuring human waste contamination. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subc

ADDRESSING EMERGING ISSUES IN WATER QUALITY ...

EPA Pesticide Factsheets

Public concern over cleanliness and safety of source and recreational waters has prompted researchers to look for indicators of water quality. Giving public water authorities multiple tools to measure and monitor levels of chemical contaminants, as well as chemical markers of contamination, simply and rapidly would enhance public protection. The goals of water quality are outlined in the Water Quality Multi-year Plan [http://intranet.epa.gov/ospintra/Planning/wq.pdf] and the research in this task falls under GPRA Goal 2, 2.3.2, Long Term Goals 1, 2, and 4. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG

PPB | What is PPB?

Cancer.gov

Pleuropulmonary blastoma (PPB) is a rare tumor of the lung that affects young children. PPB is caused by mutations in a gene known as DICER1. Not everyone with PPB has a change in DICER1. The PPB DICER1 Syndrome Study ‹an observational clinical research study is enrolling children with PPB and their families.

Comparative study of qualitative and quantitative methods to determine toxicity level of Aspergillus flavus isolates in maize.

PubMed

Shekhar, Meena; Singh, Nirupma; Dutta, Ram; Kumar, Shrvan; Mahajan, Vinay

2017-01-01

An attempt was made to compare between easy and inexpensive qualitative method (ammonia vapour test) and analytical methods (thin layer chromatography and enzyme-linked immunosorbent assay) for identification of aflatoxigenic isolates of Aspergillus flavus in maize. In this comparative study the toxicity level of A. flavus isolates exhibited 100% agreement among ammonia vapour test, ELISA and TLC for highly toxigenic (>2000 ppb) and toxigenic (501-2000 ppb) isolates while 88.5% agreement observed for least toxic (<20 ppb) isolates. In ammonia vapour test 51% of A. flavus isolates showed creamish or no colour change corresponding to least toxic/atoxic (<20ppb) category estimated by ELISA. Similarly 22% highly toxic isolates exhibited plum red colour, 12% moderately toxic indicated pink colour and 10% toxic isolates showed red colour. However, 11.5% isolates were found to be false positive in cream colour category (least toxic) and 28.5% false negatives in pink colour (moderately toxic) category. The isolates from different agroclimatic zones of maize in India showed high variability for aflatoxin B1 (AFB1) production potential ranging from 0.214-8116.61 ppb. Toxigenic potential of Aspergillus flavus isolates in culture was further validated by inoculating maize grain sample with four different isolates with varied toxin producing ability. With good agreement percentage between cultural and analytical methods the study concludes the ammonia vapour test to be easy, inexpensive, reliable and time saving method that can be used for segregating or pre-screening of contaminated samples from bulk food/feed stock.

A smog chamber comparison of a microfluidic derivatization measurement of gas-phase glyoxal and methylglyoxal with other analytical techniques

NASA Astrophysics Data System (ADS)

Pang, X.; Lewis, A. C.; Richard, A.; Baeza-Romero, M. T.; Adams, T. J.; Ball, S. M.; Daniels, M. J. S.; Goodall, I. C. A.; Monks, P. S.; Peppe, S.; Ródenas García, M.; Sánchez, P.; Muñoz, A.

2013-06-01

A microfluidic lab-on-a-chip derivatization technique has been developed to measure part per billion volume (ppbV) mixing ratios of gaseous glyoxal (GLY) and methylglyoxal (MGLY), and the method compared with other techniques in a smog chamber experiment. The method uses o-(2,3,4,5,6-pentafluorobenzyl) hydroxylamine (PFBHA) as a derivatization reagent and a microfabricated planar glass micro-reactor comprising an inlet, gas and fluid splitting and combining channels, mixing junctions, and a heated capillary reaction microchannel. The enhanced phase contact area-to-volume ratio and the high heat transfer rate in the micro-reactor result in a fast and highly efficient derivatization reaction, generating an effluent stream ready for direct introduction to a gas chromatograph-mass spectrometer (GC-MS). A linear response for GLY was observed over a calibration range 0.7 to 400 ppbV, and for MGLY of 1.2 to 300 ppbV, when derivatized under optimal reaction conditions. The method detection limits (MDLs) were 80 pptV and 200 pptV for GLY and MGLY respectively, calculated as 3 times the standard deviation of the S/N of the blank sample chromatograms. These MDLs are below or close to typical concentrations in clean ambient air. The feasibility of the technique was assessed by applying the methodology under controlled conditions to quantify of α-dicarbonyls formed during the photo-oxidation of isoprene in a large scale outdoor atmospheric simulation chamber (EUPHORE). Good general agreement was seen between microfluidic measurements and Fourier Transform Infra Red (FTIR), Broad Band Cavity Enhanced Absorption Spectroscopy (BBCEAS) and a detailed photochemical chamber box modelling calculation for both GLY and MGLY. Less good agreement was found with Proton-Transfer Reaction Time-of-Flight Mass Spectrometry (PTR-ToF-MS) and Solid Phase Microextraction (SPME) derivatization methods for MGLY measurement.

Uranium hydrogeochemical and stream sediment reconnaissance of the Arminto NTMS quadrangle, Wyoming, including concentrations of forty-three additional elements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Morgan, T.L.

1979-11-01

During the summers of 1976 and 1977, 570 water and 1249 sediment samples were collected from 1517 locations within the 18,000-km/sup 2/ area of the Arminto NTMS quadrangle of central Wyoming. Water samples were collected from wells, springs, streams, and artifical ponds; sediment samples were collected from wet and dry streams, springs, and wet and dry ponds. All water samples were analyzed for 13 elements, including uranium, and each sediment sample was analyzed for 43 elements, including uranium and thorium. Uranium concentrations in water samples range from below the detection limit to 84.60 parts per billion (ppb) with a meanmore » of 4.32 ppb. All water sample types except pond water samples were considered as a single population in interpreting the data. Pond water samples were excluded due to possible concentration of uranium by evaporation. Most of the water samples containing greater than 20 ppb uranium grouped into six clusters that indicate possible areas of interest for further investigation. One cluster is associated with the Pumpkin Buttes District, and two others are near the Kaycee and Mayoworth areas of uranium mineralization. The largest cluster is located on the west side of the Powder River Basin. One cluster is located in the central Big Horn Basin and another is in the Wind River Basin; both are in areas underlain by favorable host units. Uranium concentrations in sediment samples range from 0.08 parts per million (ppm) to 115.50 ppm with a mean of 3.50 ppm. Two clusters of sediment samples over 7 ppm were delineated. The first, containing the two highest-concentration samples, corresponds with the Copper Mountain District. Many of the high uranium concentrations in samples in this cluster may be due to contamination from mining or prospecting activity upstream from the sample sites. The second cluster encompasses a wide area in the Wind River Basin along the southern boundary of the quadrangle.« less

Basal and induced NO formation in the pharyngo-oral tract influences estimates of alveolar NO levels.

PubMed

Malinovschi, Andrei; Janson, Christer; Holm, Lena; Nordvall, Lennart; Alving, Kjell

2009-02-01

The present study analyzed how models currently used to distinguish alveolar from bronchial contribution to exhaled nitric oxide (NO) are affected by manipulation of NO formation in the pharyngo-oral tract. Exhaled NO was measured at multiple flow rates in 15 healthy subjects in two experiments: 1) measurements at baseline and 5 min after chlorhexidine (CHX) mouthwash and 2) measurements at baseline, 60 min after ingestion of 10 mg NaNO(3)/kg body wt, and 5 min after CHX mouthwash. Alveolar NO concentration (Calv(NO)) and bronchial flux (J'aw(NO)) were calculated by using the slope-intercept model with or without adjustment for trumpet shape of airways and axial diffusion (TMAD). Salivary nitrate and nitrite were measured in the second experiment. Calv(NO) [median (range)] was reduced from 1.16 ppb (0.77, 1.96) at baseline to 0.84 ppb (0.57, 1.48) 5 min after CHX mouthwash (P < 0.001). The TMAD-adjusted Calv(NO) value after CHX mouthwash was 0.50 ppb (0, 0.85). The nitrate load increased J'aw(NO) from 32.2 nl/min (12.2, 60.3) to 57.1 nl/min (22.0, 119) in all subjects and Calv(NO) from 1.47 ppb (0.73, 1.95) to 1.87 ppb (10.85, 7.20) in subjects with high nitrate turnover (>10-fold increase of salivary nitrite after nitrate load). CHX mouthwash reduced Calv(NO) levels to 1.15 ppb (0.72, 2.07) in these subjects with high nitrate turnover. All these results remained consistent after TMAD adjustment. We conclude that estimated alveolar NO concentration is affected by pharyngo-oral tract production of NO in healthy subjects, with a decrease after CHX mouthwash. Moreover, unknown ingestion of dietary nitrate could significantly increase estimated alveolar NO in subjects with high nitrate turnover, and this might be falsely interpreted as a sign of peripheral inflammation. These findings were robust for TMAD.

SU-G-201-09: Evaluation of a Novel Machine-Learning Algorithm for Permanent Prostate Brachytherapy Treatment Planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nicolae, A; Department of Physics, Ryerson University, Toronto, ON; Lu, L

Purpose: A novel, automated, algorithm for permanent prostate brachytherapy (PPB) treatment planning has been developed. The novel approach uses machine-learning (ML), a form of artificial intelligence, to substantially decrease planning time while simultaneously retaining the clinical intuition of plans created by radiation oncologists. This study seeks to compare the ML algorithm against expert-planned PPB plans to evaluate the equivalency of dosimetric and clinical plan quality. Methods: Plan features were computed from historical high-quality PPB treatments (N = 100) and stored in a relational database (RDB). The ML algorithm matched new PPB features to a highly similar case in the RDB;more » this initial plan configuration was then further optimized using a stochastic search algorithm. PPB pre-plans (N = 30) generated using the ML algorithm were compared to plan variants created by an expert dosimetrist (RT), and radiation oncologist (MD). Planning time and pre-plan dosimetry were evaluated using a one-way Student’s t-test and ANOVA, respectively (significance level = 0.05). Clinical implant quality was evaluated by expert PPB radiation oncologists as part of a qualitative study. Results: Average planning time was 0.44 ± 0.42 min compared to 17.88 ± 8.76 min for the ML algorithm and RT, respectively, a significant advantage [t(9), p = 0.01]. A post-hoc ANOVA [F(2,87) = 6.59, p = 0.002] using Tukey-Kramer criteria showed a significantly lower mean prostate V150% for the ML plans (52.9%) compared to the RT (57.3%), and MD (56.2%) plans. Preliminary qualitative study results indicate comparable clinical implant quality between RT and ML plans with a trend towards preference for ML plans. Conclusion: PPB pre-treatment plans highly comparable to those of an expert radiation oncologist can be created using a novel ML planning model. The use of an ML-based planning approach is expected to translate into improved PPB accessibility and plan uniformity.« less

Development of an inhalation unit risk factor for isoprene.

PubMed

Haney, Joseph T; Phillips, Tracie; Sielken, Robert L; Valdez-Flores, Ciriaco

2015-12-01

A unit risk factor (URF) was developed for isoprene based on evaluation of three animal studies with adequate data to perform dose-response modeling (NTP, 1994, 1999; Placke et al., 1996). Ultimately, the URF of 6.2E-08 per ppb (2.2E-08 per μg/m(3)) was based on the 95% lower confidence limit on the effective concentration corresponding to 10% extra risk for liver carcinoma in male B6C3F1 mice after incorporating appropriate adjustment factors for species differences in target tissue metabolite concentrations and inhalation dosimetry. The corresponding lifetime air concentration at the 1 in 100,000 no significant excess risk level is 160 ppb (450 μg/m(3)). This concentration is almost 4400 times lower than the lowest exposure level associated with statistically increased liver carcinoma in B6C3F1 mice in the key study (700 ppm in Placke et al., 1996) and is above typical isoprene breath concentrations reported in the scientific literature. Continuous lifetime environmental exposure to the 1 in 100,000 excess risk level of 160 ppb would be expected to raise the human blood isoprene area under the curve (AUC) less than one-third of the standard deviation of the endogenous mean blood AUC. The mean for ambient air monitoring sites in Texas (2005-2014) is approximately 0.13 ppb. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Effects of low-level SO/sub 2/ on Usnes hirta and Parmelia chlorachroa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eversman, S.

1978-01-01

Respiration rates of Usnea hirta (l.) wigg, and Parmelia chlorochroa tuck exposed in the field to SO/sub 2/ fumigation decreased significantly, compared to control rates, within 30 days at 94 ppB SO/sub 2/ and within 60 days at 33 ppB. Nearly 100% of the algal cells were plasmolyzed within 60 days. The respiration rates of P. chlorochora samples were not significantly different from those of conrol samples after 60 days of exposure to 18 ppB SO/sub 2/. The respiration rates of U. hirta samples were significantly less than those of control samples after 96 days of exposure to 18 ppBmore » SO/sub 2/. A significantly greater percentage of the algal cells were plasmolyzed in U. hirta and P. chlorochroa, compared to control samples, after 31 days of exposure to 18 ppB. Damage to the lichens was more obvious and occurred faster than damage to adjacent vascular vegetation.« less

O3, VOC, NOx, PM2.5 and Meteorological Measurements during an Inversion Episode in Utah's Uinta Basin

NASA Astrophysics Data System (ADS)

Moore, K. D.; Martin, R. S.; Hill, S.; Shorthill, H.

2011-12-01

Recent measurements found high winter ozone (O3) at several locations in northeastern Utah's Uinta Basin. Similar to Wyoming's Upper Green River Basin, the area has seen recent growth in the gas/oil sector. As a part of a more comprehensive project, a study was conducted examining the relationships between O3, volatile organic compounds (VOCs), nitrogen oxides (NOx), fine particulate matter (PM2.5), and meteorology during an inversion episode. The study took place February 21-25, 2011 at the area's population center (Vernal) and at an area within the gas/oil fields (Red Wash). At both sites, O3 and NOx, displayed expected diurnal behaviors. The 1-hr O3 concentrations ranged from 10-90 ppb at Vernal and 34-107 ppb at Red Wash. Average diurnal O3 maximums (±95% CI) were 70.4±12.1 ppb and 76.8±12.6 ppb at Vernal and Red Wash, respectively. The Red Wash average O3 diurnal curve was broader than that at Vernal and did not titrate out as rapidly in the evening and morning hours. In contrast, higher NOx was observed at Vernal, with hourly averaged values ranging from 4.5-80.2 ppb, compared to 1.5-29.7 ppb at Red Wash. The NOx tended to follow traffic patterns at both sites, with morning maximum 1-hr averages of 40.8±12.1 ppb and 20.2±8.7 ppb, respectively. A portable O3 monitor attached to a tethered balloon found high ground level O3 (70-80 ppb) and a decrease to relatively constant levels (50-60 ppb) by 150 m agl. Methane and non-methane hydrocarbons (NHMC) were collected at least twice per day using whole vial and sorbent cartridges, followed by GC-FID and GC-MS analysis. The gas/oil field samples (Red Wash) found significantly higher CH4 levels (2.71±0.32 ppm) compared to the Vernal samples (1.82±0.14 ppm). The NMHC were likewise higher at the Red Wash location. Calculation of the maximum incremental reactivity (MIR) estimated that methane, ethane, propane, acetylene, remaining alkanes, alkenes, and aromatics accounted for 7.9%, 18.5%, 4.7%, 1.0%, 20.6%, 46.7%, and 0.6%, respectively, of the Vernal ozone formation potential. For the Red Wash site, the equivalent MIRs were 7.0%, 10.9%, 4.7%, 0.5%, 32.4%, 39.6%, and 4.8%. Five collocated AirMetrics MiniVol samplers measured 23-hr average PM2.5 concentrations at each site. Collocation allowed various analyses for compositional determination. The PM2.5 levels averaged 16.4±3.9 at Vernal and 8.9±0.3 μg/m3 Red Wash. At both sites, carbonaceous material made up around 80% of the PM2.5. Elemental carbon accounted for 13.4% and 12.8% of the PM2.5 and organic carbon contributed 64.1% and 69.6%, at Vernal and Red Wash, respectively. Vertical meteorology was examined through the use of tethersondes. The period was characterized by a stagnant high pressure system until the final day of the study when an active storm system moved through the area. Vertical temperature profiles showed strong temperature inversions from the ground to >350 m agl and a very stable atmosphere throughout the study. Winds were almost always light (≤2 m/s) and changed direction through the vertical profile. Diurnal variation in the height of the surface layer was observed varied from 20-80 m agl.

Exposure to volatile organic compounds and kidney dysfunction in thin film transistor liquid crystal display (TFT-LCD) workers.

PubMed

Chang, Ta-Yuan; Huang, Kuei-Hung; Liu, Chiu-Shong; Shie, Ruei-Hao; Chao, Keh-Ping; Hsu, Wen-Hsin; Bao, Bo-Ying

2010-06-15

Many volatile organic compounds (VOCs) are emitted during the manufacturing of thin film transistor liquid crystal displays (TFT-LCDs), exposure to some of which has been reported to be associated with kidney dysfunction, but whether such an effect exists in TFT-LCD industry workers is unknown. This cross-sectional study aimed to investigate the association between exposure to VOCs and kidney dysfunction among TFT-LCD workers. The results showed that ethanol (1811.0+/-1740.4 ppb), acetone (669.0+/-561.0 ppb), isopropyl alcohol (187.0+/-205.3 ppb) and propylene glycol monomethyl ether acetate (PGMEA) (102.9+/-102.0 ppb) were the four dominant VOCs present in the workplace. The 63 array workers studied had a risk of kidney dysfunction 3.21-fold and 3.84-fold that of 61 cell workers and 18 module workers, respectively. Workers cumulatively exposed to a total level of isopropyl alcohol, PGMEA and propylene glycol monomethyl ether> or =324 ppb-year had a significantly higher risk of kidney dysfunction (adjusted OR=3.41, 95% CI=1.14-10.17) compared with those exposed to <25 ppb-year after adjustment for potential confounding factors. These findings indicated that array workers might be the group at greatest risk of kidney dysfunction within the TFT-LCD industry, and cumulative exposure to specific VOCs might be associated with kidney dysfunction. Crown Copyright 2010. Published by Elsevier B.V. All rights reserved.

Measurements of formaldehyde and acetaldehyde in the urban ambient air

NASA Astrophysics Data System (ADS)

Salas, Louis J.; Singh, Hanwant B.

Acetaldehyde and formaldehyde were measured in urban ambient air by analyzing their 2,4-dinitrophenylhydrazine derivatives with reverse-phase, high-performance liquid chromatography (HPLC). A series of nine short term field experiments were performed in eight cities. Concurrent formaldehyde measurements using the chromotropic-acid procedure show reasonable agreement (±30 %) between the two methods. Average summertime ambient urban formaldehyde (HCHO) concentrations of 10-20 ppb (10 -9v/v) are significantly higher than the average acetaldehyde (CH 3CHO) concentrations of 1-2 ppb. There is evidence of much reduced formaldehyde levels in winter months. Exceptionally high, absolute (8.5 ppb av.) and relative ( HCHO/CH 3CHO ~ 2 ) acetaldehyde concentrations are measured in the South Coast Air Basin of California.

Quartz-enhanced photoacoustic detection of ethylene using a 10.5 μm quantum cascade laser.

PubMed

Wang, Zhen; Li, Zhili; Ren, Wei

2016-02-22

A quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor has been developed for the sensitive detection of ethylene (C2H4) at 10.5 µm using a continuous-wave distributed-feedback quantum cascade laser. At this long-wavelength infrared, the key acoustic elements of quartz tuning fork and micro-resonators were optimized to improve the detection signal-to-noise ratio by a factor of >4. The sensor calibration demonstrated an excellent linear response (R2>0.999) to C2H4 concentration at the selected operating pressure of 500 and 760 Torr. With a minimum detection limit of 50 parts per billion (ppb) achieved at an averaging time of 70 s, the sensor has been deployed for measuring the C2H4 efflux during the respiration of biological samples in an agronomic environment.

A Review of Hydrazine Sensors: The State of the Art

NASA Technical Reports Server (NTRS)

Meneghelli, B. J.

2004-01-01

Several types of sensors have been developed over the past few years that quantify the vapor concentrations of the hydrazines. These sensor s are able to detect concentrations as low as 10 parts per billion (ppb) up to several parts per million (ppm). The scope of this review wi ll be focused on those sensors that are most current in the marketpla ce as either leak detectors or personnel monitors. Some technical information on the theory of operations of each hydrazine detector will a lso be included. The review will highlight current operations that utilize hydrazine sensors including the Kennedy Space Center (KSC), the United States Air Force (USAF) at Cape Canaveral Air Station (CCAS), USAF F-16 facilities. The orientation of the review will be towards giving users usable practical information on hydrazine sensors.

Exposure Assessment of Acetamide in Milk, Beef, and Coffee Using Xanthydrol Derivatization and Gas Chromatography/Mass Spectrometry

PubMed Central

2017-01-01

Acetamide has been classified as a possible human carcinogen, but uncertainties exist about its levels in foods. This report presents evidence that thermal decomposition of N-acetylated sugars and amino acids in heated gas chromatograph injectors contributes to artifactual acetamide in milk and beef. An alternative gas chromatography/mass spectrometry protocol based on derivatization of acetamide with 9-xanthydrol was optimized and shown to be free of artifactual acetamide formation. The protocol was validated using a surrogate analyte approach based on d3-acetamide and applied to analyze 23 pasteurized whole milk, 44 raw sirloin beef, and raw milk samples from 14 different cows, and yielded levels about 10-fold lower than those obtained by direct injection without derivatization. The xanthydrol derivatization procedure detected acetamide in every food sample tested at 390 ± 60 ppb in milk, 400 ± 80 ppb in beef, and 39 000 ± 9000 ppb in roasted coffee beans. PMID:29186951

Precise Measurements of the Masses of Cs, Rb and Na A New Route to the Fine Structure Constant

NASA Astrophysics Data System (ADS)

Rainville, Simon; Bradley, Michael P.; Porto, James V.; Thompson, James K.; Pritchard, David E.

2001-01-01

We report new values for the atomic masses of the alkali 133Cs, 87Rb, 85Rb, and 23Na with uncertainties ≤ 0.2 ppb. These results, obtained using Penning trap single ion mass spectrometry, are typically two orders of magnitude more accurate than previously measured values. Combined with values of h/m atom from atom interferometry measurements and accurate wavelength measurements for different atoms, these values will lead to new ppb-level determinations of the molar Planck constant N A h and the fine structure constant α. This route to α is based on simple physics. It can potentially achieve the several ppb level of accuracy needed to test the QED determination of α extracted from measurements of the electron g factor. We also demonstrate an electronic cooling technique that cools our detector and ion below the 4 K ambient temperature. This technique improves by about a factor of three our ability to measure the ion's axial motion.

Seaweeds along KwaZulu-Natal coast of South Africa-3: elemental uptake by Ulva lactuca (Sea lettuce).

PubMed

Misheer, Natasha; Kindness, A; Jonnalagadda, S B

2006-01-01

The elemental uptake by Ulva lactuca (Sea lettuce), a marine macro-algae (chlorophyta, green alga) grown richly along KwaZulu-Natal coastline. The total elemental concentrations of seven important elements, namely manganese, iron, arsenic, boron, titanium, zinc and mercury, selected based on their abundance in U. lactuca were investigated for one year cycle (June 2002 to May 2003). The four selected sampling sites, Zinkwasi, Ballito, Treasure Beach and Park Ryrie are spread over 150 km wide along the KwaZulu-Natal coastline from North to South. The Ulva lectuca possess good manganese and arsenic accumulating ability and an excellent bio-indicator for most of the metals studied. A typical U. lectuca sample at Zinkwasi (in winter) recorded Mn (25.3 +/- 1.16 ppm), Fe (21.0 +/- 0.85 ppm), As (6.2 +/- 0.30 ppm), B (935 +/- 14 ppb), Ti (863 +/- 34 ppb), Zn (421 +/- 21 ppb), and Hg (61.3 +/- 1.2 ppb). The general trend found at all sites was high elemental concentrations in winter and a decrease in concentrations from winter to spring and summer. Iron uptake was lowest in summer and autumn at all sites. Ulva lactuca recorded highest mercury levels (>400 ppb) during the spring season at the Treasure Beach site near Durban.

BOREAS TGB-10 Oxidant Concentration Data over the SSA

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Westberg, Hal; Hall, Brad; Jackson, Andrea V.

2000-01-01

The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This data set contains measured peroxide (H2O2 and total organic peroxides (ROOH)) and ozone concentrations as well as H2O2 and ROOH deposition velocities. These data were obtained at the SSA-OJP site from May to September 1994. The data are stored in tabular ASCII files. Some important results were: (1) Ozone concentrations were consistently low, 20-30 ppb, during the summer of 1994. (2) Peroxide concentrations showed a seasonal variation with highest concentrations occurring in July (IFC-2). (3) Midday H2O2 levels averaged around 1.4 ppb during IFC-2 and 0.4 - 0.5 ppb during IFC's 1 and 3. (4) Midday organic peroxide concentrations were lower, averaging 0.8 ppb during IFC-2, and 0.4 - 0.5 ppb during IFC's 1 and 3. (5) The rough pine forest canopy serves as a significant sink for H2O2. (6) Midday H2O2 deposition velocities averaged 4 - 7 cm/s. (7) Organic peroxide deposition velocities (measured as total ROOH) were approximately 40% as large as those of H2O2.

Quantifying Ozone Production throughout the Boundary Layer from High Frequency Tethered Profile Measurements during a High Ozone Episode in the Uinta Basin, Utah

NASA Astrophysics Data System (ADS)

Sterling, C. W.; Johnson, B.; Schnell, R. C.; Oltmans, S. J.; Cullis, P.; Hall, E. G.; Jordan, A. F.; Windell, J.; McClure-Begley, A.; Helmig, D.; Petron, G.

2015-12-01

During the Uinta Basin Winter Ozone Study (UBWOS) in Jan - Feb 2013, 735 tethered ozonesonde profiles were obtained at 3 sites including during high wintertime photochemical ozone production events that regularly exceeded 125 ppb. High resolution profiles of ozone and temperature with altitude, measured during daylight hours, showed the development of approximately week long high ozone episodes building from background levels of ~40 ppb to >150 ppb. The topography of the basin combined with a strong temperature inversion trapped oil and gas production effluents in the basin and the snow covered surface amplified the sun's radiation driving the photochemical ozone production at rates up to 13 ppb/hour in a cold layer capped at 1600-1700 meters above sea level. Beginning in mid-morning, ozone mixing ratios throughout the cold layer increased until late afternoon. Ozone mixing ratios were generally constant with height indicating that ozone production was nearly uniform throughout the depth of the cold pool. Although there was strong diurnal variation, ozone mixing ratios increased during the day more than decreased during the night, resulting in elevated levels the next morning; an indication that nighttime loss processes did not compensate for daytime production. Even though the 3 tethersonde sites were at elevations differing by as much as 140 m, the top of the high ozone layer was nearly uniform in altitude at the 3 locations. Mobile van surface ozone measurements across the basin confirmed this capped structure of the ozone layer; the vehicle drove out of high ozone mixing ratios at an elevation of ~1900 meters above sea level, above which free tropospheric ozone mixing ratios of ~50 ppb were measured. Exhaust plumes from a coal-fired power plant in the eastern portion of the basin were intercepted by the tethersondes. The structure of the profiles clearly showed that effluents in the plumes were not mixed downward and thus did not contribute precursor nitrogen oxides to the observed ozone production in the boundary layer.

Colloidal lithography nanostructured Pd/PdO x core-shell sensor for ppb level H2S detection.

PubMed

Benedict, Samatha; Lumdee, Chatdanai; Dmitriev, Alexandre; Anand, Srinivasan; Bhat, Navakanta

2018-06-22

In this work we report on plasma oxidation of palladium (Pd) to form reliable palladium/palladium oxide (Pd/PdO x ) core-shell sensor for ppb level H 2 S detection and its performance improvement through nanostructuring using hole-mask colloidal lithography (HCL). The plasma oxidation parameters and the sensor operating conditions are optimized to arrive at a sensor device with high sensitivity and repeatable response for H 2 S. The plasma oxidized palladium/palladium oxide sensor shows a response of 43.1% at 3 ppm H 2 S at the optimum operating temperature of 200 °C with response and recovery times of 24 s and 155 s, respectively. The limit of detection (LoD) of the plasma oxidised beam is 10 ppb. We further integrate HCL, a bottom-up and cost-effective process, to create nanodiscs of fixed diameter of 100 nm and varying heights (10, 15 and 20 nm) on 10 nm thin Pd beam which is subsequently plasma oxidized to improve the H 2 S sensing characteristics. The nanostructured Pd/PdO x sensor with nanodiscs of 100 nm diameter and 10 nm height shows an enhancement in sensing performance by 11.8% at same operating temperature and gas concentration. This nanostructured sensor also shows faster response and recovery times (15 s and 100 s, respectively) compared to the unstructured Pd/PdO x counterpart together with an experimental LoD of 10 ppb and the estimated limit going all the way down to 2 ppb. Material characterization of the fabricated Pd/PdO x sensors is done using UV-vis spectroscopy and x-ray photoemission spectroscopy.

Colloidal lithography nanostructured Pd/PdO x core–shell sensor for ppb level H2S detection

NASA Astrophysics Data System (ADS)

Benedict, Samatha; Lumdee, Chatdanai; Dmitriev, Alexandre; Anand, Srinivasan; Bhat, Navakanta

2018-06-01

In this work we report on plasma oxidation of palladium (Pd) to form reliable palladium/palladium oxide (Pd/PdO x ) core–shell sensor for ppb level H2S detection and its performance improvement through nanostructuring using hole-mask colloidal lithography (HCL). The plasma oxidation parameters and the sensor operating conditions are optimized to arrive at a sensor device with high sensitivity and repeatable response for H2S. The plasma oxidized palladium/palladium oxide sensor shows a response of 43.1% at 3 ppm H2S at the optimum operating temperature of 200 °C with response and recovery times of 24 s and 155 s, respectively. The limit of detection (LoD) of the plasma oxidised beam is 10 ppb. We further integrate HCL, a bottom-up and cost-effective process, to create nanodiscs of fixed diameter of 100 nm and varying heights (10, 15 and 20 nm) on 10 nm thin Pd beam which is subsequently plasma oxidized to improve the H2S sensing characteristics. The nanostructured Pd/PdO x sensor with nanodiscs of 100 nm diameter and 10 nm height shows an enhancement in sensing performance by 11.8% at same operating temperature and gas concentration. This nanostructured sensor also shows faster response and recovery times (15 s and 100 s, respectively) compared to the unstructured Pd/PdO x counterpart together with an experimental LoD of 10 ppb and the estimated limit going all the way down to 2 ppb. Material characterization of the fabricated Pd/PdO x sensors is done using UV–vis spectroscopy and x-ray photoemission spectroscopy.

Fish consumption habits and body burden levels of chlorinated hydrocarbons in Wisconsin sport fishermen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jones, V.B.; Anderson, H.A.; Hanrahan, L.P.

In 1985, 1% (1,600) of the 1984 fishing license holders from 10 Wisconsin counties were selected randomly to participate in a study of fishing and fish consumption habits and their relation to body burden of PCBs and DDE. Of the 801 who responded to a mail survey, 245 (30%) fished on Lake Michigan. The mean number of sport-caught fish meals eaten in 1984 was 20 meals/person. Seventy-three pounds was the mean for fish caught and kept for eating by family members in 1984, with a range of 0 to 1,470 pounds. Perch was the most commonly caught fish from Lakemore » Michigan and Lake Superior. Data indicate sport fishermen are following the health advisory suggestions for fishing and sport caught fish meal preparation to reduce accumulation of these compounds. Eighty-five percent of respondents were familiar with the health advisory, and 57% of them either changed their fishing or fish consumption habits. All 317 respondents who consumed potentially contaminated fish and a stratified sample of 155 consumers of noncontaminated fish were asked to donate a blood sample for serum analysis of PCBs and DDE. A total of 198 blood samples were collected. The use of capillary column GC analytic procedure allowed for PCB congener specific detection at 0.6 ppb. The most commonly identified PCB congeners were: 2,2',3,4,4',5' hexachlorobiphenyl; 2,2',4,4'5,5' hexachlorobiphenyl; and 2,2'3,4,4',5,5' heptachlorobiphenyl. The mean sum of identified PCBs congeners was 2.04 ppb, with a range of 0 to 27.1 ppb. The mean DDE level was 6.55 ppb with a range of 0 to 40 ppb.« less

Contribution of diet to aggregate arsenic exposures—An analysis across populations

PubMed Central

Kurzius-Spencer, Margaret; Burgess, Jefferey L.; Harris, Robin B.; Hartz, Vern; Roberge, Jason; Huang, Shuang; Hsu, Chiu-Hsieh; O'Rourke, MK

2014-01-01

The relative contribution of dietary arsenic (As) to aggregate daily exposure has not been well-characterized, especially in relation to the current EPA maximum contaminant level (MCL) of 10 p.p.b. for As in drinking water. Our objectives were to: (1) model exposure to inorganic and total As among non-seafood eaters using subject-specific data, (2) compare the contribution of food, drinking and cooking water to estimated aggregate exposure in households with variable background tap water As levels, and (3) describe the upper distribution of potential dose at different thresholds of tap water As. Dietary As intake was modeled in regional study populations and NHANES 2003–2004 using dietary records in conjunction with published food As residue data. Water As was measured in the regional studies. Among subjects exposed to tap water As >10 p.p.b., aggregate inorganic exposure was 24.5–26.1 μg/day, with approximately 30% of intake from food. Among subjects living in homes with tap water As ≤10, 5 or 3 p.p.b., aggregate inorganic As exposure was 8.6–11.8 μg/day, with 54–85% of intake from food. Median inorganic As potential dose was 0.42–0.50 μg/kg BW/day in subjects exposed to tap water As >10 p.p.b. and less than half that among subjects exposed to tap water As ≤10 p.p.b. The majority of inorganic and total As exposure is attributable to diet in subjects with tap water As

Quantitative Analysis of Mixed Halogen Dioxins and Furans in Fire Debris Utilizing Atmospheric Pressure Ionization Gas Chromatography-Triple Quadrupole Mass Spectrometry.

PubMed

Organtini, Kari L; Myers, Anne L; Jobst, Karl J; Reiner, Eric J; Ross, Brian; Ladak, Adam; Mullin, Lauren; Stevens, Douglas; Dorman, Frank L

2015-10-20

Residential and commercial fires generate a complex mixture of volatile, semivolatile, and nonvolatile compounds. This study focused on the semi/nonvolatile components of fire debris to better understand firefighter exposure risks. Using the enhanced sensitivity of gas chromatography coupled to atmospheric pressure ionization-tandem mass spectrometry (APGC-MS/MS), complex fire debris samples collected from simulation fires were analyzed for the presence of potentially toxic polyhalogenated dibenzo-p-dioxins and dibenzofurans (PXDD/Fs and PBDD/Fs). Extensive method development was performed to create multiple reaction monitoring (MRM) methods for a wide range of PXDD/Fs from dihalogenated through hexa-halogenated homologue groups. Higher halogenated compounds were not observed due to difficulty eluting them off the long column used for analysis. This methodology was able to identify both polyhalogenated (mixed bromo-/chloro- and polybromo-) dibenzo-p-dioxins and dibenzofurans in the simulated burn study samples collected, with the dibenzofuran species being the dominant compounds in the samples. Levels of these compounds were quantified as total homologue groups due to the limitations of commercial congener availability. Concentration ranges in household simulation debris were observed at 0.01-5.32 ppb (PXDFs) and 0.18-82.11 ppb (PBDFs). Concentration ranges in electronics simulation debris were observed at 0.10-175.26 ppb (PXDFs) and 0.33-9254.41 ppb (PBDFs). Samples taken from the particulate matter coating the firefighters' helmets contained some of the highest levels of dibenzofurans, ranging from 4.10 ppb to 2.35 ppm. The data suggest that firefighters and first responders at fire scenes are exposed to a complex mixture of potentially hundreds to thousands of different polyhalogenated dibenzo-p-dioxins and dibenzofurans that could negatively impact their health.

Long-term sub second-response monitoring of gaseous ammonia in ambient air by positive inhaling ion mobility spectrometry.

PubMed

Huang, Wei; Wang, Weiguo; Chen, Chuang; Li, Mei; Peng, Liying; Li, Hang; Liu, Jiwei; Hou, Keyong; Li, Haiyang

2017-12-01

A real-time dynamic measurements of ammonia (NH 3 ) is crucial for understanding the atmospheric nucleation process. A novel method was developed for on line monitoring at the sub-second time scale for the gaseous ammonia in ambient air for months, based on a positive inhaling ion mobility spectrometry (IMS) with a 63 Ni ion source. The selective detection of NH 3 was achieved using a high resolution IMS with an optimization of the drift tube temperature above 150°C. This method improved the peak-to-peak resolution significantly, thus avoided the interferences of the adjacent peaks to the quantitative analysis of NH 3 . The time resolution of the IMS was less than 0.1s at a data averaging of 10 times. The limit of detection (LOD) achieved at sub-ppb level while a linear response of peak intensity versus concentration of NH 3 in the range of 10-60ppb and 60-400ppb were obtained. The relative standard deviations (RSD), the confidence level and the errors were 1.06%, 95% and ± 0.21ppb by measuring 100ppb NH 3 for 100 times. The effect of ambient humidity could be greatly reduced by using the drift temperature of over 150°C. At last, the application of measuring the NH 3 concentration evolutions of Dalian city was performed from June 19 to December 3 in 2015. The results illustrated a potential method of using IMS for a real-time measuring atmospheric NH 3 at an unprecedented accuracy and sensitivity with long-term stability. Copyright © 2017 Elsevier B.V. All rights reserved.

Levels of Polychlorinated Biphenyls (PCBs) and Three Organochlorine Pesticides in Fish from the Aleutian Islands of Alaska

PubMed Central

Hardell, Sara; Tilander, Hanna; Welfinger-Smith, Gretchen; Burger, Joanna; Carpenter, David O.

2010-01-01

Background Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) and chlorinated pesticides, have been shown to have many adverse human health effects. These contaminants therefore may pose a risk to Alaska Natives that follow a traditional diet high in marine mammals and fish, in which POPs bioaccumulate. Methods and Findings This study examined the levels of PCBs and three pesticides [p, p′-DDE, mirex, and hexachlorobenzene (HCB)] in muscle tissue from nine fish species from several locations around the Aleutian Islands of Alaska. The highest median PCB level was found in rock sole (Lepidopsetta bilineata, 285 ppb, wet weight), while the lowest level was found in rock greenling (Hexagrammos lagocephalus, 104 ppb, wet weight). Lipid adjusted PCB values were also calculated and significant interspecies differences were found. Again, rock sole had the highest level (68,536 ppb, lipid weight). Concerning the PCB congener patterns, the more highly chlorinated congeners were most common as would be expected due to their greater persistence. Among the pesticides, p, p′-DDE generally dominated, and the highest level was found in sockeye salmon (Oncorhynchus nerka, 6.9 ppb, wet weight). The methodology developed by U.S. Environmental Protection Agency (USEPA) was used to calculate risk-based consumption limits for the analyzed fish species. For cancer health endpoints for PCBs, all species would trigger strict advisories of between two and six meals per year, depending upon species. For noncancer effects by PCBs, advisories of between seven and twenty-two meals per year were triggered. None of the pesticides triggered consumption limits. Conclusion The fish analyzed, mainly from Adak, contain significant concentrations of POPs, in particular PCBs, which raises the question whether these fish are safe to eat, particularly for sensitive populations. However when assessing any risk of the traditional diet, one must also consider the many health and cultural benefits from eating fish. PMID:20811633

The relation between respiratory illness in primary schoolchildren and the use of gas for cooking--III. Nitrogen dioxide, respiratory illness and lung infection.

PubMed

Florey, C V; Melia, R J; Chinn, S; Goldstein, B D; Brooks, A G; John, H H; Craighead, I B; Webster, X

1979-12-01

We examined the relation between lung function and respiratory illness in a population of 808 primary school children aged 6-7 years and the levels of nitrogen dioxide (NO2) in the kitchens and bedrooms in their homes. Complete data were collected on about 66% of the population. The children lived in a defined 4 square km area in Middlesbrough, Cleveland, UK. One week average outdoor levels of NO2 varied little over the area (14-24 ppb); The prevalence of respiratory illness was higher in children from gas than electric cooking homes (p approximately or equal to 0.1). Although prevalence was not related to kitchen NO2 levels (range 5-317 ppb) it increased with increasing levels of NO2 in the children's bedrooms in gas cooking homes (range 4-169 ppb, p approximately or equal to 0.1). Symptoms in siblings and parents were not related to kitchen NO2 levels. Lung function was not related to NO2 levels in the kitchen or bedroom. Because of the very low levels of NO2 at which an association with illness was observed and the inconsistency between our results in the UK and those from several studies in the US, it is possible that the NO2 levels were a proxy for some other factor more directly related to respiratory disease such as temperature or humidity.

Evidence for changes in the transcription levels of two putative P-glycoprotein genes in sea lice (Lepeophtheirus salmonis) in response to emamectin benzoate exposure.

PubMed

Tribble, Nicholas D; Burka, John F; Kibenge, Frederick S B

2007-05-01

Overexpression of P-glycoproteins (Pgps) is assumed to be a principal mechanism of resistance of nematodes and arthropods to macrocyclic lactones. Quantitative RT-PCR (Q-RT-PCR) was used to demonstrate changes in transcription levels of two putative P-glycoprotein genes, designated here as SL0525 and SL-Pgp1, in sea lice (Lepeophtheirus salmonis) following exposure to emamectin benzoate (EMB). Pre-adult L. salmonis were challenged in an EMB bioassay for 24h and gene expression was studied from lice surviving EMB concentrations of 0, 10, and 30ppb. Gene expression was measured using Q-RT-PCR with elongation factor 1 (eEF1alpha) as an internal reference gene. The results show that both target genes, SL0525 and SL-Pgp1, had significantly increased levels of expression with exposure to 10ppb EMB (p=0.11 and p=0.17, respectively) whereas the group exposed to 30ppb was on the verge of being significant (p=0.053) only in the expression of SL-Pgp1. Gene expression for SL0525 and SL-Pgp1 were increased over five-fold at 10ppb EMB. Therefore, the upregulation of these target genes may offer protection by increasing Pgp expression when lice are exposed to EMB. Our optimized Q-RT-PCR can be used to determine if over-expression of these genes could be the basis for development of resistance in sea lice and thus allow suitable alternative chemotherapeutic options to be assessed.

Eurasian continental background and regionally polluted levels of ozone and CO observed in northeast Asia

NASA Astrophysics Data System (ADS)

Pochanart, Pakpong; Kato, Shungo; Katsuno, Takao; Akimoto, Hajime

The roles of Eurasian/Siberian continental air masses transport and the impact of large-scale East Asian anthropogenic emissions on tropospheric ozone and carbon monoxide levels in northeast Asia were investigated. Seasonal behaviors of O 3 and CO mixing ratios in background continental (BC) air masses and regionally polluted continental (RPC) air masses were identified using trajectory analyses of Eurasian continental air masses and multi-year O 3 and CO data observed at Happo, a mountain site in Japan. RPC air masses show significantly higher O 3 and CO mixing ratios (annual average of 53.9±6.0 and 200±41 ppb, respectively) than BC air masses (44.4±3.6 and 167±17 ppb, respectively). Large scale anthropogenic emissions in East Asia are suggested to contribute about 10 ppb of photochemical O 3 and 32 ppb of CO at Happo. A comparative study of O 3 and CO observed at other sites, i.e., Oki Islands and Mondy in northeast Asia, showed similarities suggesting that O 3 mixing ratios in BC air masses at Happo could be representative for remote northeast Asia. However, CO mixing ratios in BC air masses at Happo are higher than the background level in Siberia. The overestimate is probably related to an increase in the CO baseline gradient between Siberia and the East Asia Pacific rim, and perturbations by sub-grid scale pollution transport and regional-scale boreal forest fires in Siberia when the background continental air masses are transported to Japan.

Vegan-mycoprotein concentrate from pea-processing industry byproduct using edible filamentous fungi.

PubMed

Souza Filho, Pedro F; Nair, Ramkumar B; Andersson, Dan; Lennartsson, Patrik R; Taherzadeh, Mohammad J

2018-01-01

Currently around one billion people in the world do not have access to a diet which provides enough protein and energy. However, the production of one of the main sources of protein, animal meat, causes severe impacts on the environment. The present study investigates the production of a vegan-mycoprotein concentrate from pea-industry byproduct (PpB), using edible filamentous fungi, with potential application in human nutrition. Edible fungal strains of Ascomycota ( Aspergillus oryzae , Fusarium venenatum , Monascus purpureus , Neurospora intermedia ) and Zygomycota ( Rhizopus oryzae ) phyla were screened and selected for their protein production yield. A. oryzae had the best performance among the tested fungi, with a protein yield of 0.26 g per g of pea-processing byproduct from the bench scale airlift bioreactor cultivation. It is estimated that by integrating the novel fungal process at an existing pea-processing industry, about 680 kg of fungal biomass attributing to about 38% of extra protein could be produced for each 1 metric ton of pea-processing byproduct. This study is the first of its kind to demonstrate the potential of the pea-processing byproduct to be used by filamentous fungi to produce vegan-mycoprotein for human food applications. The pea-processing byproduct (PpB) was proved to be an efficient medium for the growth of filamentous fungi to produce a vegan-protein concentrate. Moreover, an industrial scenario for the production of vegan-mycoprotein concentrate for human nutrition is proposed as an integrated process to the existing PPI production facilities.

Environmental and industrial factors relating to flavor tainting of fish in the upper Wisconsin river

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heil, T.P.; Lindsay, R.C.

1990-08-01

Extracts from Large Toothed Aspen (Populous grandidenta Michx.) and Jack Pine (Pinus banksiana Lamb.) contained many odor compounds found in flavor-tainted walleye from the Wisconsin River, including alkylphenols. Aspen wood contained 8 ppb of 2-isopropylphenol, and river sediments also contained low ppb levels of many alkylphenols, including 2-isopropylphenol. Thiophenol and thiocresol which sporadically cause offensive sulfury taints in Wisconsin River fish were also found in river sediment. Quantitative analysis of fish for alkylphenols supported a hypothesis involving a food chain-mediated seasonal fluctuation of alkylphenol levels in fish. Thiophenols are postulated to be derived from pulp mill activities on the river.

Association between children's blood lead levels, lead service lines, and water disinfection, Washington, DC, 1998-2006.

PubMed

Brown, Mary Jean; Raymond, Jaime; Homa, David; Kennedy, Chinaro; Sinks, Thomas

2011-01-01

Evaluate the effect of changes in the water disinfection process, and presence of lead service lines (LSLs), on children's blood lead levels (BLLs) in Washington, DC. Three cross-sectional analyses examined the relationship of LSL and changes in water disinfectant with BLLs in children <6 years of age. The study population was derived from the DC Childhood Lead Poisoning Prevention Program blood lead surveillance system of children who were tested and whose blood lead test results were reported to the DC Health Department. The Washington, DC Water and Sewer Authority (WASA) provided information on LSLs. The final study population consisted of 63,854 children with validated addresses. Controlling for age of housing, LSL was an independent risk factor for BLLs ≥ 10 μg/dL, and ≥ 5 μg/dL even during time periods when water levels met the US Environmental Protection Agency (EPA) action level of 15 parts per billion (ppb). When chloramine alone was used to disinfect water, the risk for BLL in the highest quartile among children in homes with LSL was greater than when either chlorine or chloramine with orthophosphate was used. For children tested after LSLs in their houses were replaced, those with partially replaced LSL were >3 times as likely to have BLLs ≥ 10 μg/dL versus children who never had LSLs. LSLs were a risk factor for elevated BLLs even when WASA met the EPA water action level. Changes in water disinfection can enhance the effect of LSLs and increase lead exposure. Partially replacing LSLs may not decrease the risk of elevated BLLs associated with LSL exposure. Copyright © 2010 Elsevier Inc. All rights reserved.

The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders

NASA Technical Reports Server (NTRS)

Ferrando, A. A.; Green, N. R.

1993-01-01

The effect of boron supplementation was investigated in 19 male bodybuilders ages 20-27 years. Ten were given a 2.5-mg boron supplement while 9 were given a placebo every day for 7 weeks. Plasma total and free testosterone, plasma boron, lean body mass, and strength measurements were determined on Days 1 and 49 of the study. Plasma boron values were significantly (p < 0.05) different as the experimental group increased from (+/- SD) 20.1 +/- 7.7 ppb pretest to 32.6 +/- 27.6 ppb posttest, while the control group mean decreased from 15.1 +/- 14.4 ppb pretest to 6.3 +/- 5.5 ppb posttest. Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders, and that boron supplementation had no effect on these measures.

The effect of boron supplementation on lean body mass, plasma testosterone levels, and strength in male bodybuilders.

PubMed

Ferrando, A A; Green, N R

1993-06-01

The effect of boron supplementation was investigated in 19 male bodybuilders ages 20-27 years. Ten were given a 2.5-mg boron supplement while 9 were given a placebo every day for 7 weeks. Plasma total and free testosterone, plasma boron, lean body mass, and strength measurements were determined on Days 1 and 49 of the study. Plasma boron values were significantly (p < 0.05) different as the experimental group increased from (+/- SD) 20.1 +/- 7.7 ppb pretest to 32.6 +/- 27.6 ppb posttest, while the control group mean decreased from 15.1 +/- 14.4 ppb pretest to 6.3 +/- 5.5 ppb posttest. Analysis of variance indicated no significant effect of boron supplementation on any of the dependent variables. Both groups demonstrated significant increases in total testosterone, lean body mass, 1-RM squat, and 1-RM bench press. The findings suggest that 7 weeks of bodybuilding can increase total testosterone, lean body mass, and strength in lesser trained bodybuilders, and that boron supplementation had no effect on these measures.

A modeling analysis of alternative primary and secondary US ozone standards in urban and rural areas

NASA Astrophysics Data System (ADS)

Nopmongcol, Uarporn; Emery, Chris; Sakulyanontvittaya, Tanarit; Jung, Jaegun; Knipping, Eladio; Yarwood, Greg

2014-12-01

This study employed the High-Order Decoupled Direct Method (HDDM) of sensitivity analysis in a photochemical grid model to determine US anthropogenic emissions reductions required from 2006 levels to meet alternative US primary (health-based) and secondary (welfare-based) ozone (O3) standards. Applying the modeling techniques developed by Yarwood et al. (2013), we specifically evaluated sector-wide emission reductions needed to meet primary standards in the range of 60-75 ppb, and secondary standards in the range of 7-15 ppm-h, in 22 cities and at 20 rural sites across the US for NOx-only, combined NOx and VOC, and VOC-only scenarios. Site-specific model biases were taken into account by applying adjustment factors separately for the primary and secondary standard metrics, analogous to the US Environmental Protection Agency's (EPA) relative response factor technique. Both bias-adjusted and unadjusted results are presented and analyzed. We found that the secondary metric does not necessarily respond to emission reductions the same way the primary metric does, indicating sensitivity to their different forms. Combined NOx and VOC reductions are most effective for cities, whereas NOx-only reductions are sufficient at rural sites. Most cities we examined require more than 50% US anthropogenic emission reductions from 2006 levels to meet the current primary 75 ppb US standard and secondary 15 ppm-h target. Most rural sites require less than 20% reductions to meet the primary 75 ppb standard and less than 40% reductions to meet the secondary 15 ppm-h target. Whether the primary standard is protective of the secondary standard depends on the combination of alternative standard levels. Our modeling suggests that the current 75 ppb standard achieves a 15 ppm-h secondary target in most (17 of 22) cities, but only half of the rural sites; the inability for several western cities and rural areas to achieve the seasonally-summed secondary 15 ppm-h target while meeting the 75 ppb primary target is likely driven by higher background O3 that is commonly reported in the western US. However, a 70 ppb primary standard is protective of a 15 ppm-h secondary standard in all cities and 18 of 20 rural sites we examined, and a 60 ppb primary standard is protective of a 7 ppm-h secondary standard in all cities and 19 of 20 rural sites. If EPA promulgates separate primary and secondary standards, exceedance areas will need to develop and demonstrate control strategies to achieve both. This HDDM analysis provides an illustrative screening assessment by which to estimate emissions reductions necessary to satisfy both standards.

ABSTRACT PRESENTATION--PHARMACEUTICALS AS ...

EPA Pesticide Factsheets

Pharmaceuticals comprise a large and diverse array of contaminants that can occur in the environmentfrom the combined activities and actions of multitudes of individuals as well as from veterinary andagricultural use. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for med

ION COMPOSITION ELUCIDATION (ICE) FOR ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICALS AND PERSONAL CARE PRODUCTS ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICAL AND PERSONAL CARE PRODUCTS IN ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

INTRODUCTION TO PHARMACEUTICALS AND PERSONAL ...

EPA Pesticide Factsheets

There is no abstract for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. Subtask 3: T

OVERVIEW OF PHARMACEUTICALS AND PERSONAL ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

ORIGINS AND RAMIFICATIONS OF PHARMACEUTICALS & ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICAL AND PERSONAL CARE PRODUCTS ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICALS AND PERSONAL CARE PRODUCTS ...

EPA Pesticide Factsheets

There is no abstract for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. Subtask 3: T

ORIGINS AND RAMIFICATIONS OF PHARMACEUTICALS ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICALS AS ENVIRONMENTAL ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

MERCURY MEASUREMENTS USING DIRECT-ANALYZER ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

SLIDE PRESENTATION--PHARMACEUTICALS AS ...

EPA Pesticide Factsheets

While pharmaceuticals are ubiquitous trace contaminants in the environment, thetypes, concentrations, and relative abundances of individual residues will vary depending on thegeographic locale and time of year, primarily a reflection of differing and varying prescribing andconsumption practices. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical

SYNTHETIC FRAGRANCES IN THE ENVIRONMENT ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

ENVIRONMENTAL STEWARDSHIP OF PHARMACEUTICALS ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

INVESTIGATING ENVIRONMENTAL SINKS OF MACROLIDE ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under the Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquirie

ADVANCED TOOLS FOR ASSESSING SELECTED ...

EPA Pesticide Factsheets

The purpose of this poster is to present the application and assessment of advanced technologies in a real-world environment - wastewater effluent and source waters - for detecting six drugs (azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, and methylenedioxymethamphetamine). The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technica

POTENTIAL CONCERNS/EFFECTS ON HUMAN AND ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

MEETING TODAY'S EMERGING CONTAMINANTS WITH ...

EPA Pesticide Factsheets

This presentation will explore the many facets of research and development for emerging contaminants within the USEPA's National Exposure Research Laboratories (Athens, Cincinnati, Las Vegas, and Research Triangle Park). The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for

NON-REGULATED CONTAMINANTS: EMERGING ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

DETECTION OF ILLCIT DRUGS IN MUNICIPAL ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

ADVANCED TOOLS FOR ASSESSING SELECTED ...

EPA Pesticide Factsheets

The purpose of this poster is to present the application and assessment of advanced state-of-the-art technologies in a real-world environment - wastewater effluent and source waters - for detecting six drugs [azithromycin, fluoxetine, omeprazole, levothyroxine, methamphetamine, methylenedioxymethamphetamine (MDMA)]. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansi

PRESCRIBING FOR THE ENVIRONMENT | Science Inventory ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

INVESTIGATING ENVIRONMENTAL SINKS OF MACROLIDE ...

EPA Pesticide Factsheets

Possible environmental sinks (wastewater effluents, biosolids, sediments) of macrolide antibiotics (i.e., azithromycin, roxithromycin and clarithromycin)are investigated using state-of-the-art analytical chemistry techniques. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews

MONITORING SYNTHETIC MUSK COMPOUNDS IN ...

EPA Pesticide Factsheets

Synthetic musk compounds are manufactured as fragrance materials for consumer products and are consumed in very large quantities worldwide. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. Subtask 3: To apply state-of-the-art envir

A NEW HIGH RESOLUTION MASS SPECTROMEY ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICALS IN SOURCE WATER - OVERVIEW ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

SPECIATION AND DETECTION OF ORGANOTINS FROM ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

NEW APPROACHES FOR TRACE ANALYSIS OF ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

ANTIBIOTICS IN THE ENVIRONMENTS; LESS RECOGNIZED ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

Uranium: A Dentist's perspective

PubMed Central

Toor, R. S. S.; Brar, G. S.

2012-01-01

Uranium is a naturally occurring radionuclide found in granite and other mineral deposits. In its natural state, it consists of three isotopes (U-234, U-235 and U-238). On an average, 1% – 2% of ingested uranium is absorbed in the gastrointestinal tract in adults. The absorbed uranium rapidly enters the bloodstream and forms a diffusible ionic uranyl hydrogen carbonate complex (UO2HCO3+) which is in equilibrium with a nondiffusible uranyl albumin complex. In the skeleton, the uranyl ion replaces calcium in the hydroxyapatite complex of the bone crystal. Although in North India, there is a risk of radiological toxicity from orally ingested natural uranium, the principal health effects are chemical toxicity. The skeleton and kidney are the primary sites of uranium accumulation. Acute high dose of uranyl nitrate delays tooth eruption, and mandibular growth and development, probably due to its effect on target cells. Based on all previous research and recommendations, the role of a dentist is to educate the masses about the adverse effects of uranium on the overall as well as the dental health. The authors recommended that apart from the discontinuation of the addition of uranium to porcelain, the Public community water supplies must also comply with the Environmental Protection Agency (EPA) standards of uranium levels being not more than 30 ppb (parts per billion). PMID:24478959

Small-size mass spectrometer for determining gases and volatile compounds in air during breathing

NASA Astrophysics Data System (ADS)

Kogan, V. T.; Kozlenok, A. V.; Chichagov, Yu. V.; Antonov, A. S.; Lebedev, D. S.; Bogdanov, A. A.; Moroshkin, V. S.; Berezina, A. V.; Viktorova-Leclerc, O. S.; Vlasov, S. A.; Tubol'tsev, Yu. V.

2015-10-01

We describe an automated mass spectrometer for diagnostics of deceases from the composition of exhaled air. It includes a capillary system, which performs a rapid direct feeding of the sample to the instrument without changing substantially its composition and serves for studying the dynamics of variation of the ratio between various components of exhaled air. The membrane system for introducing the sample is intended for determining low concentrations of volatile organic compounds which are biomarkers of pathologies. It is characterized by selective transmittance and ensures the detection limits of target compounds at the parts per million-parts per billion (ppm-ppb) level. A static mass analyzer operating on permanent magnets possesses advantages important for mobile devices as compared to its dynamic analogs: it is more reliable in operation, has a larger dynamic range, and can be used for determining the concentration of components in the mixture one-by-one or simultaneously. The curvilinear output boundary of the magnetic lens of the mass analyzer makes it possible to reduce its weight and size by 2.5 times without deteriorating the mass resolution. We report on the results of testing of the instrument and consider the possibility of its application for early detection of deceases of respiratory and blood circulation system, gastrointestinal tract, and endocrine system.

Impacts of rising tropospheric ozone on photosynthesis and metabolite levels on field grown soybean.

PubMed

Sun, Jindong; Feng, Zhaozhong; Ort, Donald R

2014-09-01

The response of leaf photosynthesis and metabolite profiles to ozone (O3) exposure ranging from 37 to 116 ppb was investigated in two soybean cultivars Dwight and IA3010 in the field under fully open-air conditions. Leaf photosynthesis, total non-structural carbohydrates (TNC) and total free amino acids (TAA) decreased linearly with increasing O3 levels in both cultivars with average decrease of 7% for an increase in O3 levels by 10 ppb. Ozone interacted with developmental stages and leaf ages, and caused higher damage at later reproductive stages and in older leaves. Ozone affected yield mainly via reduction of maximum rate of Rubisco carboxylation (Vcmax) and maximum rates of electron transport (Jmax) as well as a shorter growing season due to earlier onset of canopy senescence. For all parameters investigated the critical O3 levels (∼50 ppb) for detectable damage fell within O3 levels that occur routinely in soybean fields across the US and elsewhere in the world. Strong correlations were observed in O3-induced changes among yield, photosynthesis, TNC, TAA and many metabolites. The broad range of metabolites that showed O3 dose dependent effect is consistent with multiple interaction loci and thus multiple targets for improving the tolerance of soybean to O3. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Quantifying commuter exposures to volatile organic compounds

NASA Astrophysics Data System (ADS)

Kayne, Ashleigh

Motor-vehicles can be a predominant source of air pollution in cities. Traffic-related air pollution is often unavoidable for people who live in populous areas. Commuters may have high exposures to traffic-related air pollution as they are close to vehicle tailpipes. Volatile organic compounds (VOCs) are one class of air pollutants of concern because exposure to VOCs carries risk for adverse health effects. Specific VOCs of interest for this work include benzene, toluene, ethylbenzene, and xylenes (BTEX), which are often found in gasoline and combustion products. Although methods exist to measure time-integrated personal exposures to BTEX, there are few practical methods to measure a commuter's time-resolved BTEX exposure which could identify peak exposures that could be concealed with a time-integrated measurement. This study evaluated the ability of a photoionization detector (PID) to measure commuters' exposure to BTEX using Tenax TA samples as a reference and quantified the difference in BTEX exposure between cyclists and drivers with windows open and closed. To determine the suitability of two measurement methods (PID and Tenax TA) for use in this study, the precision, linearity, and limits of detection (LODs) for both the PID and Tenax TA measurement methods were determined in the laboratory with standard BTEX calibration gases. Volunteers commuted from their homes to their work places by cycling or driving while wearing a personal exposure backpack containing a collocated PID and Tenax TA sampler. Volunteers completed a survey and indicated if the windows in their vehicle were open or closed. Comparing pairs of exposure data from the Tenax TA and PID sampling methods determined the suitability of the PID to measure the BTEX exposures of commuters. The difference between BTEX exposures of cyclists and drivers with windows open and closed in Fort Collins was determined. Both the PID and Tenax TA measurement methods were precise and linear when evaluated in the laboratory using standard BTEX gases. The LODs for the Tenax TA sampling tubes (determined with a sample volume of 1,000 standard cubic centimeters which is close to the approximate commuter sample volumes collected) were orders of magnitude lower (0.04 to 0.7 parts per billion (ppb) for individual compounds of BTEX) compared to the PIDs' LODs (9.3 to 15 ppb of a BTEX mixture), which makes the Tenax TA sampling method more suitable to measure BTEX concentrations in the sub-parts per billion (ppb) range. PID and Tenax TA data for commuter exposures were inversely related. The concentrations of VOCs measured by the PID were substantially higher than BTEX concentrations measured by collocated Tenax TA samplers. The inverse trend and the large difference in magnitude between PID responses and Tenax TA BTEX measurements indicates the two methods may have been measuring different air pollutants that are negatively correlated. Drivers in Fort Collins, Colorado with closed windows experienced greater time-weighted average BTEX exposures than cyclists (p: 0.04). Commuter BTEX exposures measured in Fort Collins were lower than commuter exposures measured in prior studies that occurred in larger cities (Boston and Copenhagen). Although route and intake may affect a commuter's BTEX dose, these variables are outside of the scope of this study. Within the limitations of this study (including: small sample size, small representative area of Fort Collins, and respiration rates not taken into account), it appears health risks associated with traffic-induced BTEX exposures may be reduced by commuting via cycling instead of driving with windows closed and living in a less populous area that has less vehicle traffic. Although the PID did not reliably measure low-level commuter BTEX exposures, the Tenax TA sampling method did. The PID measured BTEX concentrations reliably in a controlled environment, at high concentrations (300-800 ppb), and in the absence of other air pollutants. In environments where there could be multiple chemicals present that may produce a PID signal (such as nitrogen dioxide), Tenax TA samplers may be a better choice for measuring BTEX. Tenax TA measurements were the only suitable method within this study to measure commuter's BTEX exposure in Fort Collins, Colorado.

Effects of clothianidin on aquatic communities: Evaluating the impacts of lethal and sublethal exposure to neonicotinoids

PubMed Central

Miles, Jesse C.; Hua, Jessica; Sepulveda, Maria S.; Krupke, Christian H.

2017-01-01

The widespread usage of neonicotinoid insecticides has sparked concern over their effects on non-target organisms. While research has largely focused on terrestrial systems, the low soil binding and high water solubility of neonicotinoids, paired with their extensive use on the landscape, puts aquatic environments at high risk for contamination via runoff events. We assessed the potential threat of these compounds to wetland communities using a combination of field surveys and experimental exposures including concentrations that are representative of what invertebrates experience in the field. In laboratory toxicity experiments, LC50 values ranged from 0.002 ppm to 1.2 ppm for aquatic invertebrates exposed to clothianidin. However, freshwater snails and amphibian larvae showed high tolerance to the chemical with no mortality observed at the highest dissolvable concentration of the insecticide. We also observed behavioral effects of clothianidin. Water bugs, Belostoma flumineum, displayed a dose-dependent reduction in feeding rate following exposure to clothianidin. Similarly, crayfish, Orconectes propinquus, exhibited reduced responsiveness to stimulus with increasing clothianidin concentration. Using a semi-natural mesocosm experiment, we manipulated clothianidin concentration (0.6, 5, and 352 ppb) and the presence of predatory invertebrates to explore community-level effects. We observed high invertebrate predator mortality with increases in clothianidin concentration. With increased predator mortality, prey survival increased by 50% at the highest clothianidin concentration. Thus, clothianidin contamination can result in a top-down trophic cascade in a community dominated by invertebrate predators. In our Indiana field study, we detected clothianidin (max = 176 ppb), imidacloprid (max = 141 ppb), and acetamiprid (max = 7 ppb) in soil samples. In water samples, we detected clothianidin (max = 0.67 ppb), imidacloprid (max = 0.18 ppb), and thiamethoxam (max = 2,568 ppb). Neonicotinoids were detected in >56% of soil samples and >90% of the water samples, which reflects a growing understanding that neonicotinoids are ubiquitous environmental contaminants. Collectively, our results underscore the need for additional research into the effects of neonicotinoids on aquatic communities and ecosystems. PMID:28334022

Detection of new VOC compounds with iCRDS

NASA Astrophysics Data System (ADS)

Huang, H.; Leen, J. B.; Gardner, A.; Gupta, M.; Baer, D. S.

2015-12-01

The instrument at Los Gatos Research (a member of ABB Inc.) which is based on incoherent cavity ringdown spectroscopy (iCRDS) that operates in the mid-infrared (bands from 860-1060 cm-1 or 970-1280 cm-1) is capable of detecting a broad range of VOCs, in situ, continuously and autonomously, for example, BTEX compounds (benzene, toluene, ethylbenzene, xylene), including differentiation of xylene isomers. Previously, we have demonstrated the measurement of trichloroethylene (TCE) in zero air with a precision of 0.17 ppb (1σ in 4 minutes), and the measurement of tetrachloroethylene (PCE) with a precision of 0.15 ppb (1σ in 4 minutes). Both of these measured precisions exceed the EPA's commercial building action limit, which for TCE is 0.92 ppb (5 µg/m3) and for PCE is 0.29 ppb (2 µg/m3). This ability has been fully demonstrated by the deployment of the instrument to the Superfund site at Moffett Naval Air Station in Mountain View, California where contaminated ground water results in vapor intrusion of TCE and PCE. For two weeks, the instrument operated continuously and autonomously, successfully measuring TCE and PCE concentrations in both the breathing zone and steam tunnel air, in excellent agreement with previous TO-15 data. In this poster, we present laboratory performance data targeting new toxic molecules with the same instrument. We have demonstrated the measurement of trichlorofluolomethane (Freon 11) in zero air with a precision of 1 ppb (3σ at 1075cm-1), and hexafluoropropene in zero air with a precision of about 0.3 ppb (3σ per spectrum). The iCRDS instrument has shown the ability to continuously and autonomously measure sub-ppb levels of toxic VOCs in the lab/field, offering an unprecedented picture of the short term dynamics associated with vapor intrusion and ground water pollution.

BOREAS TGB-10 Oxidant Flux Data over the SSA

NASA Technical Reports Server (NTRS)

Hall, Forrest G. (Editor); Conrad, Sara K. (Editor); Westberg, Hal; Hall, Brad; Jackson, Andrea V.

2000-01-01

The BOREAS TGB-10 team collected several trace gas data sets in its efforts to determine the role of biogenic hydrocarbon emissions with respect to boreal forest carbon cycles. This oxidant data set contains measured peroxide (H2O2 and total organic peroxides (ROOH)) and ozone concentrations as well as H2O2 and ROOH deposition velocities. These data were obtained at the SSA-OJP site during the summer of 1994. Measurements were made from May to September 1994. The data are stored in tabular ASCII files. Some important results were: (1) Ozone concentrations were consistently low, 20-30 ppb, during the summer of 1994. (2) Peroxide concentrations showed a seasonal variation with highest concentrations occurring in July (IFC-2). (3) Midday H2O2 levels averaged around 1.4 ppb during IFC-2 and 0.4 - 0.5 ppb during IFC's 1 and 3. (4) Midday organic peroxide concentrations were lower, averaging 0.8 ppb during IFC-2, and 0.4 - 0.5 ppb during IFC's 1 and 3. (5) The rough pine forest canopy serves as a significant sink for H2O2. (6) Midday H2O2 deposition velocities averaged 4 - 7 cm/s. (7) Organic peroxide deposition velocities (measured as total ROOH) were approximately 40% as large as those of H2O2.

Direct analysis of human breath ammonia using corona discharge ion mobility spectrometry.

PubMed

Jazan, Elham; Mirzaei, Hadi

2014-01-01

In this study, ammonia in human breath was directly determined using corona discharge ionization ion mobility spectrometry (CD-IMS) technique with several important advantages including high sensitivity, low cost, high speed, and ease of maintenance. The temperature effect on the ammonia signal was evaluated too. The results indicated that the best temperature for the investigation of breath ammonia was 150°C. The analytical results showed that the linear dynamic range was between 12 and 810ppb and the detection limit was 6.6ppb. The relative standard deviation (RSD) was obtained to be 5, 3, and 3 for 290, 348, and 522ppb, respectively. The amounts of ammonia in breath of eight healthy volunteers were measured. The values were between 236 and 1218ppb. Also, the inequality in breath ammonia levels was scrutinized over a 6h working day for three healthy volunteers. The results showed a drop in breath ammonia from the morning amount to the mid-day measurement and then, a progressive increase while the day continued. In addition, the amounts of ammonia were determined to be 1494-1553ppb in exhaled breath of two renal failure patients. The results obtained in this work revealed that the method was conveniently established without any considerable sample pretreatment for direct analysis of ammonia in human breath. Copyright © 2013 Elsevier B.V. All rights reserved.

Mycotoxigenic fungi and natural co-occurrence of mycotoxins in rainbow trout (Oncorhynchus mykiss) feeds.

PubMed

Greco, Mariana; Pardo, Alejandro; Pose, Graciela

2015-11-05

Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of <10 to 4.2 × 10⁴ CFU/g on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), <10 to 5.1 × 10⁴ CFU/g on Dichloran Chloramphenicol Peptone Agar (DCPA) and <10 to 3.6 × 10⁴ CFU/g on Dichloran 18% Glycerol Agar (DG18). The most frequent mycotoxigenic fungi were Eurotium (frequency (Fr) 25.0%), followed by Penicillium (Fr 21.4%) and Aspergillus (Fr 3.6%). The most prevalent mycotoxigenic species were E. repens (Fr 21.4%) and E. rubrum (Fr 14.3%). All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb), 50% samples with zearalenone (median 87.97 ppb) and aflatoxins (median 2.82 ppb), 25% with ochratoxin A (median 5.26 ppb) and 3.57% samples with deoxynivalenol (median 230 ppb). Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples.

Mycotoxigenic Fungi and Natural Co-Occurrence of Mycotoxins in Rainbow Trout (Oncorhynchus mykiss) Feeds

PubMed Central

Greco, Mariana; Pardo, Alejandro; Pose, Graciela

2015-01-01

Samples of rainbow trout feed were analyzed with the aim to determine the mycobiota composition and the co-occurrence of mycotoxins. A total of 28 samples of finished rainbow trout feed from hatcheries in the provinces of Río Negro and Neuquén, Argentina, were studied. Fungal counts were obtained on three culture media in the ranges of <10 to 4.2 × 104 CFU/g on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), <10 to 5.1 × 104 CFU/g on Dichloran Chloramphenicol Peptone Agar (DCPA) and <10 to 3.6 × 104 CFU/g on Dichloran 18% Glycerol Agar (DG18). The most frequent mycotoxigenic fungi were Eurotium (frequency (Fr) 25.0%), followed by Penicillium (Fr 21.4%) and Aspergillus (Fr 3.6%). The most prevalent mycotoxigenic species were E. repens (Fr 21.4%) and E. rubrum (Fr 14.3%). All samples were contaminated with mycotoxins: 64% samples were contaminated with T-2 toxin (median 70.08 ppb), 50% samples with zearalenone (median 87.97 ppb) and aflatoxins (median 2.82 ppb), 25% with ochratoxin A (median 5.26 ppb) and 3.57% samples with deoxynivalenol (median 230 ppb). Eight samples had a fumonisins contamination level below the limit of detection. Co-occurrence of six mycotoxins was determined in 7% of the samples. PMID:26556374

Excitation-emission matrix fluorescence spectroscopy in conjunction with multiway analysis for PAH detection in complex matrices.

PubMed

Nahorniak, Michelle L; Booksh, Karl S

2006-12-01

A field portable, single exposure excitation-emission matrix (EEM) fluorometer has been constructed and used in conjunction with parallel factor analysis (PARAFAC) to determine the sub part per billion (ppb) concentrations of several aqueous polycyclic aromatic hydrocarbons (PAHs), such as benzo(k)fluoranthene and benzo(a)pyrene, in various matrices including aqueous motor oil extract and asphalt leachate. Multiway methods like PARAFAC are essential to resolve the analyte signature from the ubiquitous background in environmental samples. With multiway data and PARAFAC analysis it is shown that reliable concentration determinations can be achieved with minimal standards in spite of the large convoluting fluorescence background signal. Thus, rapid fieldable EEM analyses may prove to be a good screening method for tracking pollutants and prioritizing sampling and analysis by more complete but time consuming and labor intensive EPA methods.

High sensitive formaldehyde graphene gas sensor modified by atomic layer deposition zinc oxide films

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mu, Haichuan; Zhang, Zhiqiang; Wang, Keke

2014-07-21

Zinc oxide (ZnO) thin films with various thicknesses were fabricated by Atomic Layer Deposition on Chemical Vapor Deposition grown graphene films and their response to formaldehyde has been investigated. It was found that 0.5 nm ZnO films modified graphene sensors showed high response to formaldehyde with the resistance change up to 52% at the concentration of 9 parts-per-million (ppm) at room temperature. Meanwhile, the detection limit could reach 180 parts-per-billion (ppb) and fast response of 36 s was also obtained. The high sensitivity could be attributed to the combining effect from the highly reactive, top mounted ZnO thin films, and high conductivemore » graphene base network. The dependence of ZnO films surface morphology and its sensitivity on the ZnO films thickness was also investigated.« less

Antimicrobial silver: An unprecedented anion effect

PubMed Central

Swathy, J. R.; Sankar, M. Udhaya; Chaudhary, Amrita; Aigal, Sahaja; Anshup; Pradeep, T.

2014-01-01

Silver is an indispensable metal but its use has to be minimised for sustainable growth. Much of the silver lost during use is unrecoverable; an example being its use as an antimicrobial agent, a property known since ages. While developing methods to create an affordable drinking water purifier especially for the developing world, we discovered that 50 parts per billion (ppb) of Ag+ released continuously from silver nanoparticles confined in nanoscale cages is enough to cause antimicrobial activity in conditions of normal water. Here we show that the antibacterial and antiviral activities of Ag+ can be enhanced ~1,000 fold, selectively, in presence of carbonate ions whose concentration was maintained below the drinking water norms. The protective layers of the organisms were affected during the carbonate-assisted antimicrobial activity. It is estimated that ~1,300 tons of silver can be saved annually using this new way to enhance its antimicrobial activity. PMID:25418185

Propylparaben reduces the excitability of hippocampal neurons by blocking sodium channels.

PubMed

Lara-Valderrábano, Leonardo; Rocha, Luisa; Galván, Emilio J

2016-12-01

Propylparaben (PPB) is an antimicrobial preservative widely used in food, cosmetics, and pharmaceutics. Virtual screening methodologies predicted anticonvulsant activity of PPB that was confirmed in vivo. Thus, we explored the effects of PPB on the excitability of hippocampal neurons by using standard patch clamp techniques. Bath perfusion of PPB reduced the fast-inactivating sodium current (I Na ) amplitude, causing a hyperpolarizing shift in the inactivation curve of the I Na, and markedly delayed the sodium channel recovery from the inactivation state. Also, PPB effectively suppressed the riluzole-sensitive, persistent sodium current (I NaP ). PPB perfusion also modified the action potential kinetics, and higher concentrations of PPB suppressed the spike activity. Nevertheless, the modulatory effects of PPB did not occur when PPB was internally applied by whole-cell dialysis. These results indicate that PPB reduces the excitability of CA1 pyramidal neurons by modulating voltage-dependent sodium channels. The mechanistic basis of this effect is a marked delay in the recovery from inactivation state of the voltage-sensitive sodium channels. Our results indicate that similar to local anesthetics and anticonvulsant drugs that act on sodium channels, PPB acts in a use-dependent manner. Copyright © 2016 Elsevier B.V. All rights reserved.

QEPAS based ppb-level detection of CO and N2O using a high power CW DFB-QCL.

PubMed

Ma, Yufei; Lewicki, Rafał; Razeghi, Manijeh; Tittel, Frank K

2013-01-14

An ultra-sensitive and selective quartz-enhanced photoacoustic spectroscopy (QEPAS) sensor platform was demonstrated for detection of carbon monoxide (CO) and nitrous oxide (N2O). This sensor used a state-of-the art 4.61 μm high power, continuous wave (CW), distributed feedback quantum cascade laser (DFB-QCL) operating at 10°C as the excitation source. For the R(6) CO absorption line, located at 2169.2 cm(-1), a minimum detection limit (MDL) of 1.5 parts per billion by volume (ppbv) at atmospheric pressure was achieved with a 1 sec acquisition time and the addition of 2.6% water vapor concentration in the analyzed gas mixture. For the N2O detection, a MDL of 23 ppbv was obtained at an optimum gas pressure of 100 Torr and with the same water vapor content of 2.6%. In both cases the presence of water vapor increases the detected CO and N2O QEPAS signal levels as a result of enhancing the vibrational-translational relaxation rate of both target gases. Allan deviation analyses were performed to investigate the long term performance of the CO and N2O QEPAS sensor systems. For the optimum data acquisition time of 500 sec a MDL of 340 pptv and 4 ppbv was obtained for CO and N2O detection, respectively. To demonstrate reliable and robust operation of the QEPAS sensor a continuous monitoring of atmospheric CO and N2O concentration levels for a period of 5 hours were performed.

GIS-modeled indicators of traffic-related air pollutants and adverse pulmonary health among children in El Paso, Texas.

PubMed

Svendsen, Erik R; Gonzales, Melissa; Mukerjee, Shaibal; Smith, Luther; Ross, Mary; Walsh, Debra; Rhoney, Scott; Andrews, Gina; Ozkaynak, Halûk; Neas, Lucas M

2012-10-01

Investigators examined 5,654 children enrolled in the El Paso, Texas, public school district by questionnaire in 2001. Exposure measurements were first collected in the late fall of 1999. School-level and residence-level exposures to traffic-related air pollutants were estimated using a land use regression model. For 1,529 children with spirometry, overall geographic information system (GIS)-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with a 2.4% decrement in forced vital capacity (95% confidence interval (CI): -4.0, -0.7) after adjustment for demographic, anthropomorphic, and socioeconomic factors and spirometer/technician effects. After adjustment for these potential covariates, overall GIS-modeled residential levels of traffic-related ambient air pollution (calibrated to a 10-ppb increment in nitrogen dioxide levels) were associated with pulmonary function levels below 85% of those predicted for both forced vital capacity (odds ratio (OR) = 3.10, 95% CI: 1.65, 5.78) and forced expiratory volume in 1 second (OR = 2.35, 95% CI: 1.38, 4.01). For children attending schools at elevations above 1,170 m, a 10-ppb increment in modeled nitrogen dioxide levels was associated with current asthma (OR = 1.56, 95% CI: 1.08, 2.50) after adjustment for demographic, socioeconomic, and parental factors and random school effects. These results are consistent with previous studies in Europe and California that found adverse health outcomes in children associated with modeled traffic-related air pollutants.

Interferon gamma peptidomimetic targeted to hepatic stellate cells ameliorates acute and chronic liver fibrosis in vivo.

PubMed

Bansal, Ruchi; Prakash, Jai; De Ruiter, Marieke; Poelstra, Klaas

2014-04-10

Hepatic stellate cells play a crucial role in the pathogenesis of hepatic fibrosis. Thus, pharmacological inhibition of pro-fibrotic activities of these cells might lead to an effective therapy for this disease. Among the potent anti-fibrotics, interferon gamma (IFNγ), a proinflammatory cytokine, is highly efficacious but it failed in clinical trials due to the poor efficacy and multiple adverse effects attributed to the ubiquitous IFNγ receptor (IFNγR) expression. To resolve these drawbacks, we chemically synthesized a chimeric molecule containing (a) IFNγ signaling peptide (IFNγ peptidomimetic, mimγ) that retains the agonistic activities of IFNγ but lacks an extracellular receptor recognition sequence for IFNγR; coupled via heterobifunctional PEG linker to (b) bicyclic platelet derived growth factor beta receptor (PDGFβR)-binding peptide (BiPPB) to induce internalization into the stellate cells that express PDGFβR. The synthesized targeted IFNγ peptidomimetic (mimγ-BiPPB) was extensively investigated for its anti-fibrotic and adverse effects in acute and chronic CCl4-induced liver fibrosis models in mice. Treatment with mimγ-BiPPB, after the onset of disease, markedly inhibited both early and established hepatic fibrosis as reflected by a reduced intrahepatic α-SMA, desmin and collagen-I mRNA expression and protein levels. While untargeted mimγ and BiPPB had no effect, and native IFNγ only induced a moderate reduction. Additionally, no off-target effects, e.g. systemic inflammation, were found with mimγ-BiPPB, which were substantially observed in mice treated with native IFNγ. The present study highlights the beneficial effects of a novel BiPPB mediated cell-specific targeting of IFNγ peptidomimetic to the disease-inducing cells and therefore represents a highly potential therapeutic approach to treat fibrotic diseases. Copyright © 2014 Elsevier B.V. All rights reserved.

Effects of supplemental chromium picolinate and chromium nanoparticles on performance and antibody titers of infectious bronchitis and avian influenza of broiler chickens under heat stress condition.

PubMed

Hajializadeh, Farhad; Ghahri, Hasan; Talebi, Alireza

2017-01-01

This experiment was carried out to investigate the effects of different levels chromium picolinate (CrPic) and chromium nanoparticles (nano-Cr) on the performance and immune function of broilers under heat stress condition. A total of 320 Ross 308 broiler chicks (from 21 to 42 days) were assigned randomly into eight treatment groups (four replicates per treatment, and 10 chicks per replicate) and be reared at either thermoneutral (21 ˚C) or heat stress (36 ◦ C). The treatments were control (T1) group without supplementation and heat stress, T2 as a heat stress group without supplementation, T3, T4 and T5 groups which were supplemented with 500, 1000 and 1500 ppb CrPic in diet with heat stress, respectively and T6, T7 and T8 groups which were supplemented with 500, 1000 and 1500 ppb nano-chromium in diet under heat stress, respectively. Supplementation of chromium and nano-chromium improved performance including weight gain and feed conversion ratio of heat-stressed chickens. Antibody titers against avian influenza (AI) and infectious bronchitis (IB) at 21 to 42 days of age in broilers fed supplemental chromium and nano-chromium were higher than broiler chickens fed control diet ( p < 0.05). Nano-chromium supplementation at level of 1000 ppb and CrPic at level of 1500 ppb improved the antibody titers against AI and IB of broilers under heat stress conditions. It can be concluded from these findings that dietary supplementation of CrPic and nano-Cr can improve performance and antibody titers against AI and IB under heat stress conditions in broilers.

Evaluation of contaminated drinking water and preterm birth, small for gestational age, and birth weight at Marine Corps Base Camp Lejeune, North Carolina: a cross-sectional study.

PubMed

Ruckart, Perri Zeitz; Bove, Frank J; Maslia, Morris

2014-11-20

Births during 1968-1985 at Camp Lejeune were exposed to drinking water contaminated with trichloroethylene (TCE), tetrachloroethylene (PCE), and benzene. We conducted a cross-sectional study to evaluate associations between residential prenatal exposure to contaminated drinking water at Camp Lejeune during 1968-1985 and preterm birth, small for gestational age (SGA), term low birth weight (TLBW), and mean birth weight (MBW) deficit. Birth certificates identified mothers residing at Camp Lejeune at delivery. We analyzed exposure data for the entire pregnancy and individual trimesters. For each period examined, births were categorized as unexposed if mothers did not reside at Camp Lejeune or if their residence on base received uncontaminated drinking water. Ground water contaminant fate/transport and distribution system models provided monthly estimated contaminant levels at residences. For PCE and TCE, the exposed group was divided into four levels: < median value, ≥ median value, ≥75th percentile, and ≥90th percentile. For benzene, the exposed group was categorized as <1 part per billion (ppb) versus ≥1 ppb because of sparse data. Magnitude of effect estimates and exposure response relationships were used to assess associations. Confidence intervals (CIs) indicated precision of estimates. For the highest TCE exposure category during the entire pregnancy, odds ratios (ORs) were 1.5 (95% CI: 1.2, 1.9) and 1.3 (95% CI: 0.8, 2.2) for SGA and TLBW, respectively, and reduced MBW β = -78.3 g (95% CI: -115.0, -41.7). The OR =1.3 (95% CI: 1.0, 1.6) for preterm birth and the highest PCE exposure category during the entire pregnancy. Monotonic exposure-response relationships were observed for benzene exposure during the entire pregnancy and TLBW (highest category OR =1.5, 85% CI: 0.9, 2.3). Although a monotonic association between benzene and adjusted MBW difference was also observed (highest category β = -36.2 g, 95% CI: -72.3, -0.1), the association disappeared when TCE was also added to the model. We found no evidence suggesting any other associations between outcomes and exposures. Findings suggested associations between in utero exposures to TCE and SGA, TLBW and reduced MBW; benzene and TLBW; and PCE and preterm birth.

Comparison of a bioassay and a liquid chromatography-fluorescence-mass spectrometry(n) method for the detection of incurred enrofloxacin residues in chicken tissues.

PubMed

Schneider, M J; Donoghue, D J

2004-05-01

Regulatory monitoring for most antibiotic residues in edible poultry tissues is often accomplished with accurate, although expensive and technically demanding, chemical analytical techniques. The purpose of this study is to determine if a simple, inexpensive bioassay could detect fluoroquinolone (FQ) residues in chicken muscle above the FDA established tolerance (300 ppb) comparable to a liquid chromatography-fluorescencemass spectrometry(n) method. To produce incurred enrofloxacin (ENRO) tissues (where ENRO is incorporated into complex tissue matrices) for the method comparison, 40-d-old broilers (mixed sex) were orally dosed through drinking water for 3 d at the FDA-approved dose of ENRO (50 ppm). At the end of each day of the 3-d dosing period and for 3 d postdosing, birds were sacrificed and breast and thigh muscle collected and analyzed. Both methods were able to detect ENRO at and below the tolerance level in the muscle, with limits of detection of 26 ppb (bioassay), 0.1 ppb for ENRO, and 0.5 ppb for the ENRO metabolite, ciprofloxacin (liquid chromatography-fluorescence-mass spectrometry(n)). All samples that had violative levels of antibiotic were detected by the bioassay. These results support the use of this bioassay as a screening method for examining large numbers of samples for regulatory monitoring. Positive samples should then be examined by a more extensive method, such as liquid chromatography-fluorescence-mass spectrometry(n), to provide confirmation of the analyte.

A new resin embedded with chelating motifs of biogenic methionine for the removal of Hg(II) at ppb levels.

PubMed

Ali, Shaikh A; Mazumder, Mohammad A J

2018-05-15

Cyclopolymerization of N,N-diallylmethionine hydrochloride, derived from the biogenic amino acid methionine, (90 mol%) and cross-linker tetraallylpiperazinium dichloride (10 mol%) in presence of an azo-initiator afforded pH-responsive cross-linked polyzwitterion (CPZ). The structural morphology of the resin (i.e. CPZ) was examined by the BET and FESEM-EDX analyses. The methionine embedded resin demonstrated remarkable efficacies for the removal of Hg(II) ions at ppb levels. A 50 mg-dose of the resin immersed in aqueous medium (18 mL) could reduce the concentration of Hg(II) from 200 and 400 ppb to 1.8 and 4.4 ppb, respectively, within 15 min. The resin has also proven to be remarkably effective in the removal of several toxic and priority metal pollutants from industrial wastewater. The Hg(II) adsorption followed pseudo second-order process with E a of 48.1 kJ mol -1 . The initial rapid adsorption of metal ions and subsequent slower adsorption was attributed to film and intraparticle diffusion, respectively. The SEM-EDX analyses revealed the attachment of Hg(II) ions onto the resin. The favorability of the endothermic adsorption was ensured by the negative ΔGº values. The efficient adsorption/desorption process confirmed the recyclability of the resin. The current resin demonstrated superior metal removal capacities as compared to several other adsorbents in recent works. Copyright © 2018 Elsevier B.V. All rights reserved.

Impact of Future Emissions and Climate Change on Surface Ozone over China

NASA Astrophysics Data System (ADS)

Ma, C. T.; Westervelt, D. M.; Fiore, A. M.; Rieder, H. E.; Kinney, P.; Wang, S.; Correa, G. J. P.

2017-12-01

China's immense ambient air pollution problem and world-leading greenhouse gas emissions place it at the forefront of global efforts to address these related environmental concerns. Here, we analyze the impact of ECLIPSE (Evaluating the Climate and Air Quality Impacts of Short-Lived Pollutants) future emissions scenarios representative of current legislation (CLE) and maximum technically feasible emissions reductions (MFR) on surface ozone (O3) concentrations over China in the 2030s and 2050s, in the context of a changing climate. We use a suite of simulations performed with the NOAA Geophysical Fluid Dynamics Laboratory's AM3 global chemistry-climate model. To estimate the impact of climate change in isolation on Chinese air quality, we hold emissions of air pollutants including O3 precursors fixed at 2015 levels but allow climate (global sea surface temperatures and sea ice cover) to change according to decadal averages for the years 2026-2035 and 2046-2055 from a three-member ensemble of GFDL-CM3 simulations under the RCP8.5 high warming scenario. Evaluation of the present-day simulation (2015 CLE) with observations from 1497 chiefly urban air quality monitoring stations shows that simulated surface O3 is positively biased by 26 ppb on average over the domain of China. Previous studies, however, have shown that the modeled ozone response to changes in NOx emissions over the Eastern United States mirrors the magnitude and structure of observed changes in maximum daily average 8-hour (MDA8) O3 distributions. Therefore, we use the model's simulated changes for the 2030s and 2050s to project changes in policy-relevant MDA8 O3 concentrations. We find an overall increase in MDA8 O3 for CLE scenarios in which emissions of NOx precursors are projected to increase, and under MFR scenarios, an overall decrease, with the highest changes occurring in summertime for both 2030 and 2050 MFR. Under climate change alone, the model simulates a mean summertime decrease of 1.3 ppb and wintertime increase of 3.3 ppb by 2050. Adjustment of the observed site-level MDA8 O3 distribution to reflect regionally interpolated projected changes from AM3 allows us to examine changes in the number of days in exceedance of MDA8 O3 Level I (50 ppb) and Level II (80 ppb) Chinese national ambient air quality standards.

High Incidence and Levels of Ochratoxin A in Wines Sourced from the United States.

PubMed

De Jesus, Christopher Lawrence; Bartley, Amanda; Welch, Aaron Z; Berry, John P

2017-12-21

Ochratoxin A (OTA) is one of the most prevalent mycotoxin contaminants of food crops. Among the agricultural products consequently contaminated by OTA is wine. In the present study, a sample of wines sourced from the United States was assessed for OTA. Wines were primarily analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FD) coupled to a liquid-liquid extraction (LLE) technique which was developed and validated as a simplified sample preparation approach. More than 85% of the wines evaluated were found to contain OTA, at levels above the limit-of-detection (LOD = 0.1 µg L -1 ), and 76% were above the limit-of-quantitation (LOQ = 0.3 µg L -1 ) for the LLE/HPLC-FD method. More than two-thirds of the wines above the LOQ were found to exceed 1 µg L -1 . Complementary analysis by HPLC coupled to tandem mass spectrometry (HPLC-MS/MS) confirmed OTA in 74% of the OTA-positive wines (i.e., >LOQ by HPLC-FD). Overall, both the occurrence and measured levels of OTA were generally high, specifically relative to previous assessments of OTA in wine, and two of the wines were above the only current (European Union) regulatory limit of two parts-per-billion (ppb, ~2 µg L -1 ). Possible trends with respect to geographical region and/or growing climate are noted. As the first assessment of U.S. wines in more than a decade, the overall high occurrence and levels of OTA in wine, and possible geographic and climatic trends, point to a need for regular surveillance of wines, as well as investigation of the relevant contributors to OTA occurrence toward mitigating contamination and exposure risks.

Nitrous acid (HONO) measurements during winter haze events in Beijing

NASA Astrophysics Data System (ADS)

Bloss, W.; Kramer, L. J.; Crilley, L.; Lee, J. D.; Squires, F. A.; Tong, S.

2017-12-01

Daytime HONO levels can reach several parts per billion in megacities during winter haze events and hence act as the dominant (primary) precursor to OH radicals in the urban boundary layer, and affect NOx abundance. Understanding the sources of HONO is therefore important to quantify atmospheric oxidative capacity and secondary pollutant formation during such haze events. Despite decades of research, there are still large uncertainties in HONO formation mechanisms, and as a result models often substantially underestimate peak HONO levels. In this study, measurements of HONO were performed at the Institute of Atmospheric Physics (IAP) site located in central Beijing during Nov/Dec 2016, across both haze and non-haze events. Using a commercial long-path absorption photometer (LOPAP), vertical profiles of HONO concentrations up to a height of 260 m on the IAP Meteorological Tower were performed, as well as continuous near-surface measurements. Preliminary results showed that HONO levels near the ground were very high during the winter haze events with concentrations over 10 ppbV observed. Typically, during the vertical profiles a negative gradient was observed, indicating a large HONO source close to the surface. However, during some of the profiles elevated HONO concentrations were also observed at higher altitudes pointing to a strong source within the boundary layer. Co-located NOx and SO2 measurements are used to elucidate potential HONO sources from direct emissions, homogeneous gas phase reactions and heterogeneous conversion of NO2 on surfaces. Results from ground level HONO/NOx ratios show a midday peak during clean periods indicating a photo-enhanced process, which was not apparent during hazy days. The potential impact of these findings on the OH radical budget in wintertime Beijing will be discussed.

Ozone and Ozone By-Products in the Cabins of Commercial Aircraft

PubMed Central

Weisel, Clifford; Weschler, Charles J.; Mohan, Kris; Vallarino, Jose; Spengler, John D.

2013-01-01

The aircraft cabin represents a unique indoor environment due to its high surface-to-volume ratio, high occupant density and the potential for high ozone concentrations at cruising altitudes. Ozone was continuously measured and air was sampled on sorbent traps, targeting carbonyl compounds, on 52 transcontinental U.S. or international flights between 2008 and 2010. The sampling was predominantly on planes that did not have ozone scrubbers (catalytic converters). Peak ozone levels on aircraft without catalytic convertors exceeded 100 ppb, with some flights having periods of more than an hour when the ozone levels were > 75ppb. Ozone was greatly reduced on relatively new aircraft with catalytic convertors, but ozone levels on two flights whose aircraft had older convertors were similar to those on planes without catalytic convertors. Hexanal, heptanal, octanal, nonanal, decanal and 6-methyl-5-hepten-2-one (6-MHO) were detected in the aircraft cabin at sub- to low ppb levels. Linear regression models that included the log transformed mean ozone concentration, percent occupancy and plane type were statistically significant and explained between 18 and 25% of the variance in the mixing ratio of these carbonyls. Occupancy was also a significant factor for 6-MHO, but not the linear aldehydes, consistent with 6-MHO’s formation from the reaction between ozone and squalene, which is present in human skin oils. PMID:23517299

Interlaboratory study of free cyanide methods compared to total cyanide measurements and the effect of preservation with sodium hydroxide for secondary- and tertiary-treated waste water samples.

PubMed

Stanley, Brett J; Antonio, Karen

2012-11-01

Several methods exist for the measurement of cyanide levels in treated wastewater,typically requiring preservation of the sample with sodium hydroxide to minimize loss of hydrogen cyanide gas (HCN). Recent reports have shown that cyanide levels may increase with chlorination or preservation. In this study, three flow injection analysis methods involving colorimetric and amperometric detection were compared within one laboratory, as well as across separate laboratories and equipment. Split wastewater samples from eight facilities and three different sampling periods were tested. An interlaboratory confidence interval of 3.5 ppb was calculated compared with the intralaboratory reporting limit of 2 ppb. The results show that free cyanide measurements are not statistically different than total cyanide levels. An artificial increase in cyanide level is observed with all methods for preserved samples relative to nonpreserved samples, with an average increase of 2.3 ppb. The possible loss of cyanide without preservation is shown to be statistically insignificant if properly stored up to 48 hours. The cyanide increase with preservation is further substantiated with the method of standard additions and is not a matrix interference. The increase appears to be correlated with the amount of cyanide observed without preservation, which appears to be greater in those facilities that disinfect their wastewater with chlorine, followed by dechlorination with sodium bisulfite.

Exhaled nitric oxide levels in school children in relation to IgE sensitisation and window pane condensation.

PubMed

Janson, Christer; Kalm-Stephens, Pia; Foucard, Tony; Norbäck, Dan; Alving, Kjell; Nordvall, S Lennart

2005-08-01

A positive relation between exhaled nitric oxide (NO) levels and allergen exposure has been found in some studies whereas there is less information on how non-allergen environmental factors influences exhaled NO. To study the relationship between exhaled NO levels in schoolchildren in relation to IgE sensitisation and allergenic and non-allergenic environmental factors. This study comprised 374 schoolchildren (13-14 years of age) who performed exhaled NO-measurements and skin prick tests. Exposure to allergens, respiratory infections, environmental tobacco smoke and home window pane condensation, the latter an indicator of high humidity and poor ventilation was evaluated through questionnaires. In IgE-sensitised children sensitisation to pets was a more important determinant of exhaled NO than sensitisation to pollen. Higher NO levels were found in cat-sensitised children with a cat or other furred pets at home compared to cat-sensitised children without pets (geometric mean, 24.0 vs. 13.9 ppb, P=0.03). Significantly higher exhaled NO levels were found in non-sensitised children that reported having a cold (5.7 vs. 3.8 ppb, P<0.001) or lived in homes with window pane condensation (7.1 vs. 4.4 ppb, P=0.01) than in non-sensitised children without a cold and window pane condensation, respectively. These associations were not found in children that were sensitised to inhalation allergens. Allergen exposure seems to be the most important determinant for exhaled NO levels in IgE-sensitised children whereas in non-sensitised children NO levels were associated with respiratory infections and home window pane condensation.

Evaluation of the Contributing Area for Recovery Wells at the Naval Industrial Reserve Ordnance Plant, Fridley, Minnesota

USGS Publications Warehouse

Davis, J. Hal

2007-01-01

The Naval Industrial Reserve Ordnance Plant is located on the southernmost tip of Anoka County, Minnesota, within the City of Fridley, and about one-quarter mile east of the Mississippi River. Industrial production at the plant began in 1941 and has continued since that time. Contamination spills and poor disposal practices in the past have led to significant ground-water contamination beneath the facility. A ground-water recovery (and containment) system began operation in 1992 to prevent contaminated ground-water from migrating off site. In an effort to determine the effectiveness of the recovery system, pressure transducers were installed in 23 monitoring wells, multiple hand water-level measurements were taken in an additional 56 wells, and two extensive rounds of water-level measurements were taken in all wells (one during pumping and one during non-pumping conditions). The cones of depression of the shallow flow zone wells AT-8 (17 gallons per minute (gal/min) and AT-9 (142 gal/min) overlap to form one broad cone, while the cone of depression of well AT-7 (42 gal/min) was more isolated. Shallow flow zone well AT-5A (156 gal/min) had a large, broad cone of depression which was the result of the relatively high pumping rate and the relatively high permeability of 200 feet per day (ft/d). Intermediate flow zone well AT-3A (182 gal/min) had a broad cone of depression that extended to the intermediate clays; well AT-10 (23 gal/min) had a relatively steep cone because it was screened in a relatively low-permeability zone. Deep flow zone well AT-5B (86 gal/min) had a broad cone of depression. Intermediate well AT-3A appears to be drawing water up vertically out of the deep flow zone. The combined contributing areas of recovery wells AT-7, AT-8, and AT-9 capture the high levels of trichloroethene (TCE) contamination (greater than 100 parts per billion (ppb) along their combined axis. Well AT-5A has a broad contributing area that reaches approximately halfway to the Mississippi River and captures the eastern flank of the highest levels of contamination in the shallow zone; but it does not capture the highest levels that will still discharge to the Mississippi River. The combined contributing areas of wells AT-3A and AT-10 should capture the TCE contamination in the intermediate zone that is moving off site. Well AT-5B captures about a third of the TCE contamination in the deep flow zone where the concentration exceeds 100 ppb.

Demonstration of improved sensitivity of echo interferometers to gravitational acceleration

NASA Astrophysics Data System (ADS)

Mok, C.; Barrett, B.; Carew, A.; Berthiaume, R.; Beattie, S.; Kumarakrishnan, A.

2013-08-01

We have developed two configurations of an echo interferometer that rely on standing-wave excitation of a laser-cooled sample of rubidium atoms. Both configurations can be used to measure acceleration a along the axis of excitation. For a two-pulse configuration, the signal from the interferometer is modulated at the recoil frequency and exhibits a sinusoidal frequency chirp as a function of pulse spacing. In comparison, for a three-pulse stimulated-echo configuration, the signal is observed without recoil modulation and exhibits a modulation at a single frequency as a function of pulse spacing. The three-pulse configuration is less sensitive to effects of vibrations and magnetic field curvature, leading to a longer experimental time scale. For both configurations of the atom interferometer (AI), we show that a measurement of acceleration with a statistical precision of 0.5% can be realized by analyzing the shape of the echo envelope that has a temporal duration of a few microseconds. Using the two-pulse AI, we obtain measurements of acceleration that are statistically precise to 6 parts per million (ppm) on a 25 ms time scale. In comparison, using the three-pulse AI, we obtain measurements of acceleration that are statistically precise to 0.4 ppm on a time scale of 50 ms. A further statistical enhancement is achieved by analyzing the data across the echo envelope so that the statistical error is reduced to 75 parts per billion (ppb). The inhomogeneous field of a magnetized vacuum chamber limited the experimental time scale and resulted in prominent systematic effects. Extended time scales and improved signal-to-noise ratio observed in recent echo experiments using a nonmagnetic vacuum chamber suggest that echo techniques are suitable for a high-precision measurement of gravitational acceleration g. We discuss methods for reducing systematic effects and improving the signal-to-noise ratio. Simulations of both AI configurations with a time scale of 300 ms suggest that an optimized experiment with improved vibration isolation and atoms selected in the mF=0 state can result in measurements of g statistically precise to 0.3 ppb for the two-pulse AI and 0.6 ppb for the three-pulse AI.

Assimilation of IASI partial tropospheric columns with an Ensemble Kalman Filter over Europe

NASA Astrophysics Data System (ADS)

Coman, A.; Foret, G.; Beekmann, M.; Eremenko, M.; Dufour, G.; Gaubert, B.; Ung, A.; Schmechtig, C.; Flaud, J.-M.; Bergametti, G.

2011-09-01

Partial lower tropospheric ozone columns provided by the IASI (Infrared Atmospheric Sounding Interferometer) instrument have been assimilated into a chemistry-transport model at continental scale (CHIMERE) using an Ensemble Kalman Filter (EnKF). Analyses are made for the month of July 2007 over the European domain. Launched in 2006, aboard the MetOp-A satellite, IASI shows high sensitivity for ozone in the free troposphere and low sensitivity at the ground; therefore it is important to evaluate if assimilation of these observations can improve free tropospheric ozone, and possibly surface ozone. The analyses are validated against independent ozone observations from sondes, MOZAIC1 aircraft and ground based stations (AIRBASE - the European Air quality dataBase) and compared with respect to the free run of CHIMERE. These comparisons show a decrease in error of 6 parts-per-billion (ppb) in the free troposphere over the Frankfurt area, and also a reduction of the root mean square error (respectively bias) at the surface of 19% (33%) for more than 90% of existing ground stations. This provides evidence of the potential of data assimilation of tropospheric IASI columns to better describe the tropospheric ozone distribution, including surface ozone, despite the lower sensitivity. The changes in concentration resulting from the observational constraints were quantified and several geophysical explanations for the findings of this study were drawn. The corrections were most pronounced over Italy and the Mediterranean region, on the average we noted an average reduction of 8-9 ppb in the free troposphere with respect to the free run, and still a reduction of 5.5 ppb at ground, likely due to a longer residence time of air masses in this part associated to the general circulation pattern (i.e. dominant western circulation) and to persistent anticyclonic conditions over the Mediterranean basin. This is an important geophysical result, since the ozone burden is large over this area, with impact on the radiative balance and air quality. 1 Measurements of OZone, water vapour, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft ( http://mozaic.aero.obs-mip.fr/web/)

Assimilation of IASI partial tropospheric columns with an Ensemble Kalman Filter over Europe

NASA Astrophysics Data System (ADS)

Coman, A.; Foret, G.; Beekmann, M.; Eremenko, M.; Dufour, G.; Gaubert, B.; Ung, A.; Schmechtig, C.; Flaud, J.-M.; Bergametti, G.

2012-03-01

Partial lower tropospheric ozone columns provided by the IASI (Infrared Atmospheric Sounding Interferometer) instrument have been assimilated into a chemistry-transport model at continental scale (CHIMERE) using an Ensemble Square Root Kalman Filter (EnSRF). Analyses are made for the month of July 2007 over the European domain. Launched in 2006, aboard the MetOp-A satellite, IASI shows high sensitivity for ozone in the free troposphere and low sensitivity at the ground; therefore it is important to evaluate if assimilation of these observations can improve free tropospheric ozone, and possibly surface ozone. The analyses are validated against independent ozone observations from sondes, MOZAIC1 aircraft and ground based stations (AIRBASE - the European Air quality dataBase) and compared with respect to the free run of CHIMERE. These comparisons show a decrease in error of 6 parts-per-billion (ppb) in the free troposphere over the Frankfurt area, and also a reduction of the root mean square error (respectively bias) at the surface of 19% (33%) for more than 90% of existing ground stations. This provides evidence of the potential of data assimilation of tropospheric IASI columns to better describe the tropospheric ozone distribution, including surface ozone, despite the lower sensitivity. The changes in concentration resulting from the observational constraints were quantified and several geophysical explanations for the findings of this study were drawn. The corrections were most pronounced over Italy and the Mediterranean region, we noted an average reduction of 8-9 ppb in the free troposphere with respect to the free run, and still a reduction of 5.5 ppb at ground, likely due to a longer residence time of air masses in this part associated to the general circulation pattern (i.e. dominant western circulation) and to persistent anticyclonic conditions over the Mediterranean basin. This is an important geophysical result, since the ozone burden is large over this area, with impact on the radiative balance and air quality. 1 Measurements of OZone, water vapour, carbon monoxide and nitrogen oxides by in-service AIrbus airCraft (http://mozaic.aero.obs-mip.fr/web/).

Trihalomethanes in Comerio Drinking Water and Their Reduction by Nanostructured Materials

DOE PAGES

Bourdon, Jorge Hernandez; Linares, Francisco Marquez

2014-01-01

The formation of disinfection by-products (DBPs) during chlorination of drinking water is an issue which has drawn significant scientific attention due to the possible adverse effects that these compounds have on human health and the formation of another DBPs. Some factors that affect the formation of DBPs include: chlorine dose and residue, contact time, temperature, pH and natural organic matter (NOM). The most frequently detected DBPs in drinking water are trihalomethanes (THMs) and haloacetic acids (HAAs). The MCLs are standards established by the United States Environmental Protection Agency (USEPA) for drinking water quality established in Stage 1, Disinfectants and Disinfectionmore » Byproducts Rule (DBPR), and they limit the amount of potentially hazardous substances that are allowed in drinking water. The water quality data for THMs were evaluated in the Puerto Rico Aqueduct and Sewer Authority (PRASA). During this evaluation, the THMs exceeded the maximum contamination limit (MCLs) for the Comerio Water Treatment Plant (CWTP). USEPA classified the THMs as Group B2 carcinogens (shown to cause cancer in laboratory animals). This research evaluated the THMs concentrations in the following sampling sites: CWTP, Río Hondo and Piñas Abajo schools, Comerio Health Center (CDT), and the Vázquez Ortiz family, in the municipality of Comerio Puerto Rcio. The results show that the factors affecting the formation of THMs occur in different concentrations across the distribution line. Furthermore, there are not specific ranges to determine the formation of THMs in drinking water when the chemical and physical parameters were evaluated. Three different nanostructured materials (graphene, mordenite (MOR) and multiwalled carbon nanotubes (MWCNTs)) were used in this research, to reduce the THMs formation by adsorption in specific contact times. The results showed that graphene is the best nanomaterial to reduce THMs in drinking water. Graphene can reduce 80 parts per billion (ppb) of THMs in about 2 hours. In addition mordenite can reduce approximately 80 ppb of THMs and MWCNTs adsorbs 71 ppb of THMs in the same period of time respectively. Finally, in order to complement the adsorption results previously obtained, total organic carbon (TOC) analyses were measured, after different contact times with the nanomaterials.« less

Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments

NASA Astrophysics Data System (ADS)

Hagan, David H.; Isaacman-VanWertz, Gabriel; Franklin, Jonathan P.; Wallace, Lisa M. M.; Kocar, Benjamin D.; Heald, Colette L.; Kroll, Jesse H.

2018-01-01

The use of low-cost air quality sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions, and there is thus a critical need for understanding and optimizing the performance of such sensors in the field. Here we describe the deployment, calibration, and evaluation of electrochemical sensors on the island of Hawai`i, which is an ideal test bed for characterizing such sensors due to its large and variable sulfur dioxide (SO2) levels and lack of other co-pollutants. Nine custom-built SO2 sensors were co-located with two Hawaii Department of Health Air Quality stations over the course of 5 months, enabling comparison of sensor output with regulatory-grade instruments under a range of realistic environmental conditions. Calibration using a nonparametric algorithm (k nearest neighbors) was found to have excellent performance (RMSE < 7 ppb, MAE < 4 ppb, r2 > 0.997) across a wide dynamic range in SO2 (< 1 ppb, > 2 ppm). However, since nonparametric algorithms generally cannot extrapolate to conditions beyond those outside the training set, we introduce a new hybrid linear-nonparametric algorithm, enabling accurate measurements even when pollutant levels are higher than encountered during calibration. We find no significant change in instrument sensitivity toward SO2 after 18 weeks and demonstrate that calibration accuracy remains high when a sensor is calibrated at one location and then moved to another. The performance of electrochemical SO2 sensors is also strong at lower SO2 mixing ratios (< 25 ppb), for which they exhibit an error of less than 2.5 ppb. While some specific results of this study (calibration accuracy, performance of the various algorithms, etc.) may differ for measurements of other pollutant species in other areas (e.g., polluted urban regions), the calibration and validation approaches described here should be widely applicable to a range of pollutants, sensors, and environments.

PPB | About

Cancer.gov

The Pleuropulmonary Blastoma (PPB) DICER1 Syndrome Study ‹an observational clinical research study is enrolling children with PPB and their families. The goal of the study is to improve the care of children with PPB and other tumors associated with DICER1.

Increased levels of ethane, a non-invasive, quantitative, direct marker of n-3 lipid peroxidation, in the breath of patients with schizophrenia.

PubMed

Puri, Basant K; Ross, Brian M; Treasaden, Ian H

2008-04-01

This study directly assessed whether there was a change in the level of exhaled ethane, which provides a non-invasive, quantitative, direct measure of n-3 lipid peroxidation, in the breath of patients with schizophrenia. Samples of alveolar air were obtained from 20 subjects with schizophrenia and 23 age- and sex-matched healthy control subjects. The air samples were analyzed for ethane using mass spectrometry. The mean level of ethane in the schizophrenia sample [5.15 (S.E. 0.56) ppb] was significantly higher than that of the healthy controls [2.63 (S.E. 0.31) ppb; p<0.0005]. A further sub-analysis showed that nicotine dependence was unlikely to be the cause of this difference. These results suggest that the measurement of exhaled ethane levels may offer a non-invasive direct biomarker of increased n-3 lipid peroxidation in schizophrenia.

Method for Trace Oxygen Detection

NASA Technical Reports Server (NTRS)

Man, Kim Fung (Inventor); Boumsellek, Said (Inventor); Chutjian, Ara (Inventor)

1997-01-01

Trace levels of molecular oxygen are measured by introducing a gas containing the molecular oxygen into a target zone, and impacting the molecular oxygen in the target zone with electrons at the O(-) resonant energy level for dissociative electron attachment to produce O(-) ions. Preferably, the electrons have an energy of about 4 to about 10 eV. The amount of O(-) ions produced is measured, and is correlated with the molecular oxygen content in the target zone. The technique is effective for measuring levels of oxygen below 50 ppb. and even less than 1 ppb. The amount of O(-) can be measured in a quadrupole mass analyzer. Best results are obtained when the electrons have an energy of about 6 to about 8 eV. and preferably about 6.8 eV. The method can be used for other species by selecting the appropriate electron energy level.

Olfactory Transcriptional Analysis of Salmon Exposed to Mixtures of Chlorpyrifos and Malathion Reveal Novel Molecular Pathways of Neurobehavioral Injury

PubMed Central

Wang, Lu; Espinoza, Herbert M.; MacDonald, James W.; Bammler, Theo K.; Williams, Chase R.; Yeh, Andrew; Louie, Ke’ale W.; Marcinek, David J.; Gallagher, Evan P.

2016-01-01

Pacific salmon exposed to sublethal concentrations of organophosphate pesticides (OP) have impaired olfactory function that can lead to loss of behaviors that are essential for survival. These exposures often involve mixtures and can occur at levels below those which inhibit acetylcholinesterase (AChE). In this study, juvenile Coho salmon were exposed for 24 h to either 0.1, 0.5, or 2.5 ppb chlorpyrifos (CPF), 2, 10, or 50 ppb malathion (MAL), or binary mixtures of 0.1 CPF:2 ppb MAL, 0.5 CPF:10 ppb MAL, or 2.5 CPF:10 ppb MAL to mimic single and binary environmental exposures. Microarray analysis of olfactory rosettes from pesticide-exposed salmon revealed differentially expressed genes involved in nervous system function and signaling, aryl hydrocarbon receptor signaling, xenobiotic metabolism, and mitochondrial dysfunction. Coho exposed to OP mixtures exhibited a more pronounced loss in detection of a predatory olfactory cue relative to those exposed to single compounds, whereas respirometry experiments demonstrated that exposure to OPs, individually and in mixtures, reduced maximum respiratory capacity of olfactory rosette mitochondria. The observed molecular, biochemical, and behavioral effects occurred largely in the absence of effects on brain AChE. In summary, our results provide new insights associated with the sublethal neurotoxic effects of OP mixtures relevant to environmental exposures involving molecular and cellular pathways of injury to the salmon olfactory system that underlie neurobehavioral injury. PMID:26494550

Formaldehyde Surface Distributions and Variability in the Mexico City Basin

NASA Astrophysics Data System (ADS)

Junkermann, W.; Mohr, C.; Steinbrecher, R.; Ruiz Suarez, L.

2007-05-01

Formaldehyde ambient air mole fractions were measured throughout the dry season in March at three different locations in the Mexico City basin. The continuously running instruments were operated at Tenago del Aire, a site located in the Chalco valley in the southern venting area of the basin, at the Intituto Mexicano del Petroleo (IMP) in the northern part of the city and about 30 km north of the city at the campus of the Universidad Tecnològica de Tecamac (UTTEC). The technique used is the Hantzsch technology with a time resolution of 2 minutes and a detection limit of 100 ppt. Daily maxima peaked at 35 ppb formaldehyde in the city and about 15 to 20 ppb at the other sites. During night formaldehyde levels dropped to about 5 ppb or less. It is evident that the observed spatial and temporal variability in near surface formaldehyde distributions is strongly affected by local and regional advection processes.

Genetic interrelationships among phosphorus, nitrogen, calcium, and energy bioavailability in a growing chicken population.

PubMed

Ankra-Badu, G A; Pesti, G M; Aggrey, S E

2010-11-01

A random-mating population was used to study the genetic interrelationship between phytate P (PPB), Ca (CaB), N (NB), and energy bioavailability (EB), BW at 4 wk of age, relative growth (RG), and feed conversion ratio (FCR). Heritability estimates for PPB, CaB, NB, and EB were 0.09, 0.13, 0.16, and 0.10, respectively, and those of BW, RG, and FCR were 0.66, 0.15, and 0.10, respectively. Genetic correlations between PPB and BW, and FCR were moderate and negative, suggesting that improvement in PPB will impair growth. The genetic correlations between PPB and CaB, and EB and RG were positive and moderate, indicating that improvement in PPB would also lead to improved CaB, EB, and RG. Energy bioavailability was positively correlated with CaB, NB, PPB, and BW. Even though the genetic correlation between EB and the other traits measured, except RG and FCR, ranged from low to moderate, improving the ability of birds to utilize caloric energy in the feed would consequently improve PPB as well as growth. Improving PPB would reduce the amount of P in excreta and provide an additional savings if exogenous phytase were not added to poultry feed. The genetic correlation between PPB and NB was low but positive, whereas NB had a positive genetic correlation with BW. Therefore, selecting on NB will result in positive correlated responses in BW and PPB. Improving PPB and NB will not only improve productivity, but also reduce the polluting effects of P and N on the environment.

Unmanned aerial system laser based measurements of ammonia and methane emissions from animal feeding operations

NASA Astrophysics Data System (ADS)

Shadman, S.; McHale, L.; Miller, T.; Yalin, A.

2017-12-01

In the US, 40 Tg of ammonia is emitted every year into the atmosphere via agricultural activities. Ammonia is the third most abundant nitrogen containing species in the atmosphere and it has important impacts on atmospheric chemistry, health, and the environment. Since the atmospheric lifetime of ammonia is a few days, it typically deposits to the ground close to its source. In this study we are developing two laser-based sensors to measure ammonia and methane emissions from concentrated animal feeding operations (CAFOs) with the specific goal of quantifying the dry deposition of ammonia in the first few kilometers downwind of the CAFOs. Since methane is nonreactive and does not undergo dry deposition, its change in concentration with downwind distance is due to dispersion alone. We therefore plan to use methane as a conservative tracer, and will infer the ammonia deposition from the changing (deceasing) ratio of ammonia to methane as a function of downwind position. The laser sensors (ammonia and methane) developed in this study are relatively lightweight (<3.5 kg), low power (<40 W) and achieve part-per-billion level concentration sensitivity via sensitive open-path absorption spectroscopy methods. The sensors are designed for simultaneous airborne measurements of both species on a 12 foot Telemaster unmanned aerial system (UAS). The methane sensor employs cavity ring-down spectroscopy (CRDS) at 1.65 um with a distributed feedback laser and has effective cavity length of 20 km. The ammonia sensor employs wavelength modulation spectroscopy (WMS) with a quantum cascade laser at 10.33 um with a Herriot multipass cell (19 m effective length). In order to minimize the thermal expansion effects, most mounts and physical structures are made from carbon-fiber. For each sensor, a custom electronics module has been designed to control and power the electro-optic components, as well as to acquire, analyze, and save data (including concentration, temperature, pressure, and GPS time and position). The sensors have been characterized in the lab (Allan variance) and show sensitivities of 1.5 ppb (at 1 Hz) and 20 ppb (at 1 Hz), for ammonia and methane respectively.

RELATIONSHIPS BETWEEN LEVELS OF VOLATILE ORGANIC COMPOUNDS IN AIR AND BLOOD FROM THE GENERAL POPULATION

EPA Science Inventory

Background: The relationships between levels of volatile organic compounds (VOCs) in blood and air have not been well characterized in the general population where exposure concentrations are generally at ppb levels. Objectives: This study investigates relationships between ...

Measurements of Volatile Organic Compounds Using Proton Transfer Reaction - Mass Spectrometry during the MILAGRO 2006 Campaign

NASA Astrophysics Data System (ADS)

Fortner, E. C.; Zheng, J.; Zhang, R.; Berk Knighton, W.; Volkamer, R. M.; Sheehy, P.; Molina, L.; André, M.

2009-01-01

Volatile organic compounds (VOCs) were measured by proton transfer reaction - mass spectrometry (PTR-MS) on a rooftop in the urban mixed residential and industrial area North Northeast of downtown Mexico City as part of the Megacity Initiative - Local and Global Research Observations (MILAGRO) 2006 field campaign. Thirty eight individual masses were monitored during the campaign and many species were quantified including methanol, acetaldehyde, toluene, the sum of C2 benzenes, the sum of C3 benzenes, acetone, isoprene, benzene, and ethyl acetate. The VOC measurements were analyzed to gain a better understanding of the type of VOCs present in the MCMA, their diurnal patterns, and their origins. Diurnal profiles of weekday and weekend/holiday aromatic VOC concentrations showed the influence of vehicular traffic during the morning rush hours and during the afternoon hours. Plumes including elevated toluene as high as 216 parts per billion (ppb) and ethyl acetate as high as 183 ppb were frequently observed during the late night and early morning hours, indicating the possibility of significant industrial sources of the two compounds in the region. Wind fields during those peak episodes revealed no specific direction for the majority of the toluene plumes but the ethyl acetate plumes arrived at the site when winds were from the Southwest or West. The PTR-MS measurements combined with other VOC measuring techniques at the field site as well as VOC measurements conducted in other areas of the Mexico City Metropolitan Area (MCMA) will help to develop a better understanding of the spatial pattern of VOCs and its variability in the MCMA.

Geologic reconnaissance and geochemical sampling survey of molybdenum mineralization near Schiestler Peak, Temple Peak Quadrangle, Sublette County, Wyoming

USGS Publications Warehouse

Lee, G.K.; Antweiler, J.C.; Love, J.D.; Benedict, J.F.

1982-01-01

A brief geologic reconnaissance and geochemical survey of molybdenum mineralization near Schiestler Peak, Sublette County, Wyo., indicates that molybdenite occurs in this area as disseminations and blebs in granitic or quartz monzonitic rocks intruded by felsic dikes of similar composition. Samples of stream sediments, panned concentrates from stream sediments, soils, rocks, and water were collected in the geochemical survey. Analytical results show that in reconnaissance, panned concentrates are the best of the sample types used in this study to detect molybdenum mineralization. More detailed analysis of the distribution of the molybdenum is best achieved through the collection of rock samples. Hydrothermal alteration is generally not conspicuous in the study area; however, rock samples that contain molybdenite are usually slightly enriched in silver, copper, lead, and in several instances, gold. Conversely, there appear to be negative associations between molybdenum and zinc and between molybdenum and several of the rare-earth elements. Mo concentrations in the rock samples with no visible molybdenite range from undetectable at a sensitivity of 5 parts per million (ppm) to 700 ppm. Mo content in rock samples containing visible molybdenite ranges from 10 ppm to greater than 2,000 ppm. Stream-sediment values range from undetected to 15 ppm; panned concentrates from undetected to 15 ppm; soils from undetected to 20 ppm. Analyses of the water samples indicate Mo concentrations from 0.8 parts per billion (ppb) to 4.8 ppb. As currently understood, this deposit is not extensive or continuous, but drilling to provide information on the vertical extent of mineralization may alter this opinion.

Prostate tissue metal levels and prostate cancer recurrence in smokers.

PubMed

Neslund-Dudas, Christine; Kandegedara, Ashoka; Kryvenko, Oleksandr N; Gupta, Nilesh; Rogers, Craig; Rybicki, Benjamin A; Dou, Q Ping; Mitra, Bharati

2014-02-01

Although smoking is not associated with prostate cancer risk overall, smoking is associated with prostate cancer recurrence and mortality. Increased cadmium (Cd) exposure from smoking may play a role in progression of the disease. In this study, inductively coupled plasma mass spectrometry was used to determine Cd, arsenic (As), lead (Pb), and zinc (Zn) levels in formalin-fixed paraffin embedded tumor and tumor-adjacent non-neoplastic tissue of never- and ever-smokers with prostate cancer. In smokers, metal levels were also evaluated with regard to biochemical and distant recurrence of disease. Smokers (N = 25) had significantly higher Cd (median ppb, p = 0.03) and lower Zn (p = 0.002) in non-neoplastic tissue than never-smokers (N = 21). Metal levels were not significantly different in tumor tissue of smokers and non-smokers. Among smokers, Cd level did not differ by recurrence status. However, the ratio of Cd ppb to Pb ppb was significantly higher in both tumor and adjacent tissue of cases with distant recurrence when compared with cases without distant recurrence (tumor tissue Cd/Pb, 6.36 vs. 1.19, p = 0.009, adjacent non-neoplastic tissue Cd/Pb, 6.36 vs. 1.02, p = 0.038). Tissue Zn levels were also higher in smokers with distant recurrence (tumor, p = 0.039 and adjacent non-neoplastic, p = 0.028). These initial findings suggest that prostate tissue metal levels may differ in smokers with and without recurrence. If these findings are confirmed in larger studies, additional work will be needed to determine whether variations in metal levels are drivers of disease progression or are simply passengers of the disease process.

Atmospheric oxygenation three billion years ago.

PubMed

Crowe, Sean A; Døssing, Lasse N; Beukes, Nicolas J; Bau, Michael; Kruger, Stephanus J; Frei, Robert; Canfield, Donald E

2013-09-26

It is widely assumed that atmospheric oxygen concentrations remained persistently low (less than 10(-5) times present levels) for about the first 2 billion years of Earth's history. The first long-term oxygenation of the atmosphere is thought to have taken place around 2.3 billion years ago, during the Great Oxidation Event. Geochemical indications of transient atmospheric oxygenation, however, date back to 2.6-2.7 billion years ago. Here we examine the distribution of chromium isotopes and redox-sensitive metals in the approximately 3-billion-year-old Nsuze palaeosol and in the near-contemporaneous Ijzermyn iron formation from the Pongola Supergroup, South Africa. We find extensive mobilization of redox-sensitive elements through oxidative weathering. Furthermore, using our data we compute a best minimum estimate for atmospheric oxygen concentrations at that time of 3 × 10(-4) times present levels. Overall, our findings suggest that there were appreciable levels of atmospheric oxygen about 3 billion years ago, more than 600 million years before the Great Oxidation Event and some 300-400 million years earlier than previous indications for Earth surface oxygenation.

Air pollutant mapping with a mobile laboratory during the BEE-TEX field study

NASA Astrophysics Data System (ADS)

Yacovitch, T. I.; Herndon, S. C.; Roscioli, J. R.; Floerchinger, C. R.; Knighton, W. B.; Kolb, C. E., Jr.

2016-12-01

The region surrounding the Houston ship channel (Texas, USA) is home to a high density of petrochemical facilities, many of which emit air toxics of concern to human health. Several residential neighborhoods also abut these industrial areas. The Aerodyne Mobile Laboratory was deployed to the Houston ship channel and surrounding areas during the Benzene and Other Toxics Exposure (BEE-TEX) field study in February of 2015. We evaluate atmospheric concentrations of volatile organic hydrocarbons and other hazardous air pollutants, including benzene, 1,3-butadiene, toluene, xylenes and ethylbenzenes, styrene and nitrogen dioxide. Measurements are focused in the Manchester neighborhood, bordered by industry on the north, a rail yard on the south and a highway on the west. Two other neighborhoods are sampled to a lesser degree: Harrisburg and Galena Park. The most likely measured concentration of 1,3-butadiene in the Manchester neighborhood (0.17 ppb) exceeds the Environmental Protection Agency's E-5 lifetime cancer risk level of 0.14 ppb. In all three neighborhoods, the measured benzene concentration falls below or within the E-5 lifetime cancer risk levels of 0.4-1.4 ppb for benzene. Pollution maps as a function of wind direction show the impact of nearby sources.

Effects of ambient and elevated level of ozone on Brassica campestris L. with special reference to yield and oil quality parameters.

PubMed

Tripathi, Ruchika; Agrawal, S B

2012-11-01

Tropospheric ozone (O(3)) has become a serious threat to growth and yield of important agricultural crops over Asian regions including India. Effect of elevated O(3) (ambient+10ppb) was studied on Brassica campestris L. (cv. Sanjukta and Vardan) in open top chambers under natural field conditions. Eight hourly mean ambient O(3) concentration varied from 26.3ppb to 69.5ppb during the growth period. Plants under O(3) exposure showed reductions in photosynthetic rate, reproductive parameters, yield as well as seed and oil quality. Cultivar Sanjukta showed more reduction in photosynthetic characteristics, reproductive structures and seed and oil quality. However, total yield was more affected in Vardan. Exposure of O(3) increased the degree of unsaturation and level of PUFA, ω-6fatty acid, linolenic acid and erucic acid in oil indicating the deterioration of its quality. The study further confirmed that there is a correspondence between O(3) induced change in photosynthetic processes, reproductive development and yield and did not find any compensatory response in the final yield. Copyright © 2012 Elsevier Inc. All rights reserved.

Products of ozone-initiated chemistry in a simulated aircraft environment.

PubMed

Wisthaler, Armin; Tamás, Gyöngyi; Wyon, David P; Strøm-Tejsen, Peter; Space, David; Beauchamp, Jonathan; Hansel, Armin; Märk, Tilmann D; Weschler, Charles J

2005-07-01

We used proton-transfer-reaction mass spectrometry (PTR-MS) to examine the products formed when ozone reacted with the materials in a simulated aircraft cabin, including a loaded high-efficiency particulate air (HEPA) filter in the return air system. Four conditions were examined: cabin (baseline), cabin plus ozone, cabin plus soiled T-shirts (surrogates for human occupants), and cabin plus soiled T-shirts plus ozone. The addition of ozone to the cabin without T-shirts, at concentrations typically encountered during commercial air travel, increased the mixing ratio (v:v concentration) of detected pollutants from 35 ppb to 80 ppb. Most of this increase was due to the production of saturated and unsaturated aldehydes and tentatively identified low-molecular-weight carboxylic acids. The addition of soiled T-shirts, with no ozone present, increased the mixing ratio of pollutants in the cabin air only slightly, whereas the combination of soiled T-shirts and ozone increased the mixing ratio of detected pollutants to 110 ppb, with more than 20 ppb originating from squalene oxidation products (acetone, 4-oxopentanal, and 6-methyl-5-hepten-2-one). For the two conditions with ozone present, the more-abundant oxidation products included acetone/propanal (8-20 ppb), formaldehyde (8-10 ppb), nonanal (approximately 6 ppb), 4-oxopentanal (3-7 ppb), acetic acid (approximately 7 ppb), formic acid (approximately 3 ppb), and 6-methyl-5-hepten-2-one (0.5-2.5 ppb), as well as compounds tentatively identified as acrolein (0.6-1 ppb) and crotonaldehyde (0.6-0.8 ppb). The odor thresholds of certain products were exceeded. With an outdoor air exchange of 3 h(-1) and a recirculation rate of 20 h(-1), the measured ozone surface removal rate constant was 6.3 h(-1) when T-shirts were not present, compared to 11.4 h(-1) when T-shirts were present.

Adolescents' Observations of Parent Pain Behaviors: Preliminary Measure Validation and Test of Social Learning Theory in Pediatric Chronic Pain.

PubMed

Stone, Amanda L; Walker, Lynn S

2017-01-01

Evaluate psychometric properties of a measure of adolescents’ observations of parental pain behaviors and use this measure to test hypotheses regarding pain-specific social learning. We created a proxy-report of the Patient Reported Outcomes Measurement Information System (PROMIS) Pain Behavior–Short Form (PPB) for adolescents to report on parental pain behaviors, which we labeled the PPB-Proxy. Adolescents (n = 138, mean age = 14.20) with functional abdominal pain completed the PPB-Proxy and a parent completed the PPB. Adolescents and their parents completed measures of pain and disability during the adolescent’s clinic visit for abdominal pain. Adolescents subsequently completed a 7-day pain diary period. The PPB-Proxy moderately correlated with the PPB, evidencing that adolescents observe and can report on parental pain behaviors. Both the PPB-Proxy and PPB significantly correlated with adolescents’ pain-related disability. Parental modeling of pain behaviors could represent an important target for assessment and treatment in pediatric chronic pain patients.

No Difference in Reoperations at 2 Years Between Ceramic-on-metal and Metal-on-metal THA: A Randomized Trial.

PubMed

Engh, C Anderson; Sritulanondha, Supatra; Korczak, Abigail; Whalen, Terrence David; Naudie, Douglas D R; McCalden, Richard W; MacDonald, Steven J

2016-02-01

Hard-on-hard bearings for total hip arthroplasty continue to warrant analysis even though crosslinked polyethylene is performing very well. Ceramic-on-metal (CoM) has low in vitro wear and did well in an early clinical trial. We report on a prospective, randomized, multicenter investigational device trial comparing CoM with metal-on-metal (MoM). (1) Is there a difference in the number or type of revisions comparing CoM with MoM? (2) Are cobalt and chromium metal levels different for CoM and MoM THA? Between August 2005 and October 2006, of 1015 patients screened, 390 patients were enrolled at 11 centers and randomized to 194 CoM and 196 MoM bearings. There was no difference in the preoperative patient demographics between the study groups. Mean followup was 50 months (range, 22-75 months). Seventy-two patients from two centers had metal level analysis. With the numbers available, there was no difference in the proportion of patients undergoing revisions between the MoM and the CoM cohorts (MOM: 3% [six of 196]; COM: 1.5% [three of 194]; p = 0.50). Four MoM revisions were unrelated to the bearing surface. Two had bearing surface-related reoperations, one for an aseptic lymphocyte-dominated vasculitis-associated lesion and one for elevated metal levels with acetabular malposition. None of the CoM revisions were related to the bearing surface. The metal level analysis revealed that in contrast to the CoM, the MoM bearing group had increasing values of erythrocyte and serum cobalt from 1 to 5 years (CoM erythrocyte 0.45-0.55 ppb, p = 0.11 and CoM serum 0.88-0.85, p = 0.55, and MoM erythrocyte 0.32-0.51 ppb, p < 0.01 and MoM serum 0.65-1.01 ppb, p < 0.01). In addition, the MoM cobalt levels in erythrocytes and serum at 5 years were more variable than at 1 year (erythrocyte interquartile range [IQR], 0.26-0.44 to 0.31-1.21 ppb and serum IQR, 0.42-0.80 to 0.64-2.20 ppb, p < 0.02 for both). Although both bearings performed well at short-term followup, the CoM bearing group had no wear-related revisions and maintained consistently low metal levels. The MoM cobalt elevations may be important considering recent reports of taper corrosion. This CoM bearing was approved by the FDA but withdrawn from the market because of low sales. If it were available, the authors would not use CoM until long-term data were available. The bearing would have to outperform crosslinked polyethylene because it is unlikely that CoM metal levels will return to normal. Level I, therapeutic study.

PPB | What is the DICER1 gene?

Cancer.gov

DICER1 is a gene that manages the function of other genes. Inherited changes in DICER1 can result in a variety of tumors, including pleuropulmonary blastoma (PPB). The PPB DICER1 Syndrome Study ‹an observational clinical research study is enrolling children with PPB and their families.

Mercury Contamination in Costa Rica

NASA Astrophysics Data System (ADS)

Varekamp, J. C.; Haynes, A.; Balcom, P. H.

2012-12-01

Recent measurements of Hg in air in the central valley of Costa Rica produced some remarkably high values (up to 700 ng Hg/m3;Castillo et al., 2011), raising concerns for public health. We made a broad assessment of Hg as an environmental contaminant in Costa Rica, and sampled and analyzed lake and wetland sediment and soils to derive atmospheric Hg deposition rates. We also measured Hg(0) in air in three locations, and sampled local fish that were analyzed for Hg. We set up a sampling program of Hg in hair of Costa Ricans, sampling hair from a broad crossection of the population, in combination with dietary and personal information. The lake sediments had Hg concentrations between 34 and 316 ppb Hg, with several lakes at common natural background concentrations (20-100 ppb Hg). Some lakes showed a Hg contamination component with concentrations well above simple background values. These sediments also were very rich in organic matter, and the high Hg concentrations may be a result of Hg focusing from the watersheds into the lake depositional environments. Deduced atmospheric deposition rates of Hg range from 0.16-0.25 ng Hg/cm2 per year, which is at the low end of the global range of measured wet atmospheric deposition rates. The observed Hg concentrations in sediment and soils thus can be characterized as natural background to mildly contaminated, but nothing that would indicate Hg inventories as expected from the reported high Hg air burdens. Some of our Hg(0) in air measurements were done at the same locations as those done earlier and yielded values between 0.6-4.2 ng Hg/m3; these values are similar to the low range measurements of Castillo et al. (their night time values), but we found no evidence in 2011 for their high daytime values. The range of a few ng Hg/m3 in air is compatible with global Hg dispersion modeling. Fish tissue of Trout and Tilapia gave a range of 68-112 ppb Hg (wet weight base), well below the 300 ppb Hg EPA alert level. Overall, these data do not point to a major local source of environmental Hg in Costa Rica, which would be most likely geothermal or volcanic in origin. We sampled hair from 53 people in San Jose, Heredia, and surrounding villages. The Hg(hair) contents ranged from 97-13,840 ppb Hg, with >50% of the subjects sampled above the USEPA alert level of 1000 ppb Hg. Three individuals had Hg> 8000 ppb Hg, which is a matter of concern. From the dietary information we calculated that 76% of the subjects sampled had an Hg intake above the USEPA recommended level of 0.1 microgram/kg bodyweight per day, largely from large marine fish such as tuna, swordfish, and shark. Many of the fish are imported and the local marine fish probably obtained their Hg burden outside the Costa Rica coastal region. In conclusion, there does not seem to be a direct large natural volcanic/geothermal Hg source in Costa Rica that may create public health concerns. However, the Costa Rican people studied by us have overall high Hg(hair) which seems to be related to their level of large marine fish consumption, which in several cases may be a matter of health concern.

Using Metal Complex Ion-Molecule Reactions in a Miniature Rectilinear Ion Trap Mass Spectrometer to Detect Chemical Warfare Agents

NASA Astrophysics Data System (ADS)

Graichen, Adam M.; Vachet, Richard W.

2013-06-01

The gas-phase reactions of a series of coordinatively unsaturated [Ni(L)n]y+ complexes, where L is a nitrogen-containing ligand, with chemical warfare agent (CWA) simulants in a miniature rectilinear ion trap mass spectrometer were investigated as part of a new approach to detect CWAs. Results show that upon entering the vacuum system via a poly(dimethylsiloxane) (PDMS) membrane introduction, low concentrations of several CWA simulants, including dipropyl sulfide (simulant for mustard gas), acetonitrile (simulant for the nerve agent tabun), and diethyl phosphite (simulant for nerve agents sarin, soman, tabun, and VX), can react with metal complex ions generated by electrospray ionization (ESI), thereby providing a sensitive means of detecting these compounds. The [Ni(L)n]2+ complexes are found to be particularly reactive with the simulants of mustard gas and tabun, allowing their detection at low parts-per-billion (ppb) levels. These detection limits are well below reported exposure limits for these CWAs, which indicates the applicability of this new approach, and are about two orders of magnitude lower than electron ionization detection limits on the same mass spectrometer. The use of coordinatively unsaturated metal complexes as reagent ions offers the possibility of further tuning the ion-molecule chemistry so that desired compounds can be detected selectively or at even lower concentrations.

PHARMACEUTICALS IN THE ENVIRONMENT: SOURCES ...

EPA Pesticide Factsheets

An issue that began to receive more attention by environmental scientists in the late 1990s was the conveyancy of pharmaceuticals in the environment by way of their use in human and veterinary medical practices and personal care The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, intervi

ION COMPOSITION ELUCIDATION (ICE) OF IONS FROM ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

Polymer nanocomposite nanomechanical cantilever sensors: material characterization, device development and application in explosive vapour detection.

PubMed

Seena, V; Fernandes, Avil; Pant, Prita; Mukherji, Soumyo; Rao, V Ramgopal

2011-07-22

This paper reports an optimized and highly sensitive piezoresistive SU-8 nanocomposite microcantilever sensor and its application for detection of explosives in vapour phase. The optimization has been in improving its electrical, mechanical and transduction characteristics. We have achieved a better dispersion of carbon black (CB) in the SU-8/CB nanocomposite piezoresistor and arrived at an optimal range of 8-9 vol% CB concentration by performing a systematic mechanical and electrical characterization of polymer nanocomposites. Mechanical characterization of SU-8/CB nanocomposite thin films was performed using the nanoindentation technique with an appropriate substrate effect analysis. Piezoresistive microcantilevers having an optimum carbon black concentration were fabricated using a design aimed at surface stress measurements with reduced fabrication process complexity. The optimal range of 8-9 vol% CB concentration has resulted in an improved sensitivity, low device variability and low noise level. The resonant frequency and spring constant of the microcantilever were found to be 22 kHz and 0.4 N m(-1) respectively. The devices exhibited a surface stress sensitivity of 7.6 ppm (mN m(-1))(-1) and the noise characterization results support their suitability for biochemical sensing applications. This paper also reports the ability of the sensor in detecting TNT vapour concentration down to less than six parts per billion with a sensitivity of 1 mV/ppb.

Laser photoacoustic sensor for air toxicity measurements

NASA Astrophysics Data System (ADS)

Prasad, Coorg R.; Lei, Jie; Shi, Wenhui; Li, Guangkun; Dunayevskiy, Ilya; Patel, C. Kumar N.

2012-06-01

US EPA's Clean Air Act lists 187 hazardous air pollutants (HAP) or airborne toxics that are considered especially harmful to health, and hence the measurement of their concentration is of great importance. Numerous sensor systems have been reported for measuring these toxic gases and vapors. However, most of these sensors are specific to a single gas or able to measure only a few of them. Thus a sensor capable of measuring many of the toxic gases simultaneously is desirable. Laser photoacoustic spectroscopy (LPAS) sensors have the potential for true broadband measurement when used in conjunction with one or more widely tunable laser sources. An LPAS gas analyzer equipped with a continuous wave, room temperature IR Quantum Cascade Laser tunable over the wavelength range of 9.4 μm to 9.7 μm was used for continuous real-time measurements of multiple gases/chemical components. An external cavity grating tuner was used to generate several (75) narrow line output wavelengths to conduct photoacoustic absorption measurements of gas mixtures. We have measured various HAPs such as Benzene, Formaldehyde, and Acetaldehyde in the presence of atmospheric interferents water vapor, and carbon dioxide. Using the preliminary spectral pattern recognition algorithm, we have shown our ability to measure all these chemical compounds simultaneously in under 3 minutes. Sensitivity levels of a few part-per-billion (ppb) were achieved with several of the measured compounds with the preliminary laboratory system.

PHARMACEUTICALS AND PERSONAL CARE PRODUCTS ...

EPA Pesticide Factsheets

This presentation briefly summarizes some of what is known and not known about the occurrence of drugs in the environment, the potential for chronic effects on wildlife (and some instances of acute effects), the relevance of drug residues in drinking water to consumer risk perception, and actions that can be taken to reduce environmental exposure. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs.

PHARMACEUTICALS & PERSONAL CARE PRODUCTS AS ...

EPA Pesticide Factsheets

Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processes and human influence. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-revi

US EPA, NERL-LAS VEGAS ACTIVITIES AND RESEARCH ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

Introduction to Pharmaceuticals and Personal Care Products ...

EPA Pesticide Factsheets

Those chemical pollutants that are regulated under various international, federal, and state programs represent but a small fraction of the universe of chemicals that occur in the environment as a result of both natural processes and human influence. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-revi

SOURCES & ORIGINS OF PPCPS: A COMPLEX ISSUE ...

EPA Pesticide Factsheets

There is no abstract for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. Subtask 3: T

PRESENTATION ON PPCPS IN THE ENVIRONMENT: AN ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PPCPS IN THE ENVIRONMENT: AN OVERVIEW OF THE ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PHARMACEUTICALS IN THE ENVIRONMENT: A ...

EPA Pesticide Factsheets

This presentation briefly summarizes some of what is known, and not known about the occurrence of drugs in the environment, the potential for effects on wildlife, the relevance of drug residues in drinking water to consumer risk perception, and actions that can be taken to reduce environmental exposure. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited t

PRESENTED 04/05/2006: MERCURY MEASUREMENTS ...

EPA Pesticide Factsheets

While traditional methods for determining mercury in solid samples involve the use of aggressive chemicals to dissolve the matrix and the use of other chemicals to properly reduce the mercury to the volatile elemental form, pyrolysis-based analyzers can be used by directly weighing the solid in a sampling boat and initiating the instrumental analysis for total mercury. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee wo

FATE OF SYNTHETIC MUSK COMPOUNDS IN AN AQUATIC ...

EPA Pesticide Factsheets

To be presented is an overview of the chemistry, the monitoring methodology, and the statistical evaluation of concentrations obtained from the analysis of a suite of these compounds (e.g., Galaxolide®, musk xylene, and amino musk xylene) in different environmental compartments. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations,

TELEPHONIC PRESENTATION: MERCURY ...

EPA Pesticide Factsheets

While traditional methods for determining mercury in solid samples involve the use of aggressive chemicals to dissolve the matrix and the use of other chemicals to properly reduce the mercury to the volatile elemental form, pyrolysis-based analyzers can be used by directly weighing the solid in a sampling boat and initiating the instrumental analysis for total mercury. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee wo

PCCPS IN THE ENVIRONMENT: AN OVERVIEW OF THE ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PPCPS AS UBIQUITOUS POLLUTANTS FROM HEALTH AND ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

MEDICATION DISPOSAL AS A SOURCE FOR DRUGS AS ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

PRESENTATION FOR THE PPCPS IN THE ENVIRONMENT ...

EPA Pesticide Factsheets

There is no abstract available for this product. If further information is requested, please refer to the bibliographic citation and contact the person listed under Contact Field. The research focused on in the subtasks is the development and application of state-of the-art technologies to meet the needs of the public, Office of Water, and ORD in the area of Water Quality. Located In the subtasks are the various research projects being performed in support of this Task and more in-depth coverage of each project. Briefly, each project's objective is stated below.Subtask 1: To integrate state-of-the-art technologies (polar organic chemical integrative samplers, advanced solid-phase extraction methodologies with liquid chromatography/electrospray/mass spectrometry) and apply them to studying the sources and fate of a select list of PPCPs. Application and improvement of analytical methodologies that can detect non-volatile, polar, water-soluble pharmaceuticals in source waters at levels that could be environmentally significant (at concentrations less than parts per billion, ppb). IAG with USGS ends in FY05. APM 20 due in FY05.Subtask 2: Coordination of interagency research and public outreach activities for PPCPs. Participate on NSTC Health and Environment subcommittee working group on PPCPs. Web site maintenance and expansion, invited technical presentations, invited articles for peer-reviewed journals, interviews for media, responding to public inquiries. S

Determination of transfer rate and nature of the residue(s) in milk from {sup 14}C-atrazine cows

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thalacker, F.W.; Ash, S.G.; Simoneaux, B.J.

1996-10-01

In order to determine the rate of transfer and the nature of the atrazine residues present in milk, lactating dairy cattle were treated with atrazine at three concentrations, 0.764 ppm, 0.0747 ppm and 0.0085 ppm (dry weight of food consumed). The concentrations were selected to bridge the gap between the concentration used for EPA metabolism studies (10 ppm) and the potential exposure level of dairy cattle to atrazine and its chlorotriazine metabolites through feed. The cattle were dosed following the morning milking for nine consecutive days with a single capsule bolus of {sup 14}C-atrazine. Milk was collected twice daily andmore » aliquots of each milking and the individual cow`s daily pool of milk were analyzed by liquid scinitllation counting (LSC). The concentrations of {sup 14}C-residues in the milk plateaued on approximately day 3 and the mean {sup 14}C-atrazine levels in milk were 11.2 ppb, 1.13 ppb and 0.152 ppb for the high, middle and low dosed animals, respectively. The transfer of radioactive level of exposure to {sup 14}C-atrazine. The nature of the residues in milk were determined by extracting milk samples and analysis by HPLC, TLC or Aminex chromatography. Diaminchlorotriazine was the only chlorinated metabolite in the milk, constituting approximately 65% to 75% of the total radioactive residues (TRR).« less

Global and regional kinematics with GPS

NASA Technical Reports Server (NTRS)

King, Robert W.

1994-01-01

The inherent precision of the doubly differenced phase measurement and the low cost of instrumentation made GPS the space geodetic technique of choice for regional surveys as soon as the constellation reached acceptable geometry in the area of interest: 1985 in western North America, the early 1990's in most of the world. Instrument and site-related errors for horizontal positioning are usually less than 3 mm, so that the dominant source of error is uncertainty in the reference frame defined by the satellites orbits and the tracking stations used to determine them. Prior to about 1992, when the tracking network for most experiments was globally sparse, the number of fiducial sites or the level at which they could be tied to an SLR or VLBI reference frame usually, set the accuracy limit. Recently, with a global network of over 30 stations, the limit is set more often by deficiencies in models for non-gravitational forces acting on the satellites. For regional networks in the northern hemisphere, reference frame errors are currently about 3 parts per billion (ppb) in horizontal position, allowing centimeter-level accuracies over intercontinental distances and less than 1 mm for a 100 km baseline. The accuracy of GPS measurements for monitoring height variations is generally 2-3 times worse than for horizontal motions. As for VLBI, the primary source of error is unmodeled fluctuations in atmospheric water vapor, but both reference frame uncertainties and some instrument errors are more serious for vertical than horizontal measurements. Under good conditions, daily repeatabilities at the level of 10 mm rms were achieved. This paper will summarize the current accuracy of GPS measurements and their implication for the use of SLR to study regional kinematics.

Characterization of organics, microorganisms, desert soils, and Mars-like soils by thermal volatilization coupled to mass spectrometry and their implications for the search for organics on Mars by Phoenix and future space missions.

PubMed

Navarro-González, Rafael; Iñiguez, Enrique; de la Rosa, José; McKay, Christopher P

2009-10-01

A key goal for astrobiology is the search for evidence of life on Mars. Because liquid water is a fundamental environmental requirement for life, the recent set of missions to Mars have focused on a strategy known as "follow the water." Since life is made of organic molecules, a logical next step is "follow the organics." However, organics are expected to be present at very low levels on Mars, which would make their detection challenging. Viking was unable to detect organics at parts per billion (ppb), but the effective upper limit could be higher due to the low efficiency of the thermal volatilization (TV) step in releasing organics. Due to its ease of use, TV is still the method selected for current and future NASA and ESA missions. Here, we show that when organics are present in the soil at levels above 1500 parts per million (ppm), there are several characteristic organic fragments detected by TV-mass spectrometry; however, when the levels are below <150 ppm, TV oxidizes them, and no organic fragments are released. Instead, nitric oxide (NO) is produced and can be used to determine quantitatively the organic content if the C/N ratio is determined. Any atmospheric NO sorbed or mineral nitrogen (e.g., nitrates) present in the soil would release NO by TV at distinctive temperature regimes that would not overlap with the organic nitrogen source. Therefore, we suggest that monitoring NO provides the best chance for Phoenix and other future Mars missions to detect nitrogen-containing organics in the soil or ice.

Climatological simulations of ozone and atmospheric aerosols in the Greater Cairo region

DOE Office of Scientific and Technical Information (OSTI.GOV)

Steiner, A. L.; Tawfik, A. B.; Shalaby, A.

An integrated chemistry-climate model (RegCM4-CHEM) simulates present-day climate, ozone and tropospheric aerosols over Egypt with a focus on Greater Cairo (GC) region. The densley populated GC region is known for its severe air quality issues driven by high levels of anthropogenic pollution in conjuction with natural sources such as dust and agricultural burning events. We find that current global emission inventories underestimate key pollutants such as nitrogen oxides and anthropogenic aerosol species. In the GC region, average-ground-based NO2 observations of 40-60 ppb are substantially higher than modeled estimates (5-10 ppb), likely due to model grid resolution, improper boundary layer representation,more » and poor emissions inventories. Observed ozone concentrations range from 35 ppb (winter) to 80 ppb (summer). The model reproduces the seasonal cycle fairly well, but modeled summer ozone is understimated by approximately 15 ppb and exhibits little interannual variability. For aerosols, springtime dust events dominate the seasonal aerosol cycle. The chemistry-climate model captures the springtime peak aerosol optical depth (AOD) of 0.7-1 but is slightly greater than satellite-derived AOD. Observed AOD decreases in the summer and increases again in the fall due to agricultural burning events in the Nile Delta, yet the model underestimates this fall observed AOD peak, as standard emissions inventories underestimate this burning and the resulting aerosol emissions. Our comparison of modeled gas and particulate phase atmospheric chemistry in the GC region indicates that improved emissions inventories of mobile sources and other anthropogenic activities are needed to improve air quality simulations in this region.« less

Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

NASA Astrophysics Data System (ADS)

Sarkar, C.; Sinha, V.; Kumar, V.; Rupakheti, M.; Panday, A.; Mahata, K. S.; Rupakheti, D.; Kathayat, B.; Lawrence, M. G.

2015-09-01

The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the Valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterize the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs by deploying a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS)-the first such deployment in South Asia. 71 ion peaks (for which measured ambient concentrations exceeded the 2 σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the Valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m/Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The highest average VOC mixing ratios during the measurement period were (in rank order): acetaldehyde (8.8 ppb), methanol (7.4 ppb), acetone (4.2 ppb), benzene (2.7 ppb), toluene (1.5 ppb), isoprene (1.1 ppb), acetonitrile (1.1 ppb), C8-aromatics (~ 1 ppb), furan (~ 0.5 ppb), and C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m/z = 69.070) and furan (m/z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde (~ 9 ppb), acetonitrile (~ 1 ppb) and isoprene (~ 1 ppb) to be among the highest reported till date. Two "new" ambient compounds namely, formamide (m/z = 46.029) and acetamide (m/z = 60.051), which can photochemically produce isocyanic acid in the atmosphere, are reported in this study along with nitromethane (a tracer for diesel exhaust) which has only recently been detected in ambient studies. Two distinct periods were selected during the campaign for detailed analysis: the first was associated with high wintertime emissions of biogenic isoprene, and the second with elevated levels of ambient acetonitrile, benzene and isocyanic acid from biomass burning activities. Emissions from biomass burning and biomass co-fired brick kilns were found to be the dominant sources for compounds such as propyne, propene, benzene and propanenitrile which correlated strongly with acetonitrile (r2 > 0.7), a chemical tracer for biomass burning. The calculated total VOC OH reactivity was dominated by acetaldehyde (24.0 %), isoprene (20.2 %) and propene (18.7 %), while oxygenated VOCs and isoprene collectively contributed to more than 68 % of the total ozone production potential. Based on known SOA yields and measured ambient concentrations in the Kathmandu Valley, the relative SOA production potential of VOCs were: benzene > naphthalene > toluene > xylenes > monoterpenes > trimethyl-benzenes > styrene > isoprene. The first ambient measurements from any site in South Asia of compounds with significant health effects such as isocyanic acid, formamide, acetamide, naphthalene and nitromethane have been reported in this study. Our results suggest that mitigation of intense wintertime biomass burning activities, in particular point sources such biomass co-fired brick kilns, would be important to reduce the emission and formation of toxic VOCs (such as benzene and isocyanic acid) in the Kathmandu Valley and improve its air quality.

Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley

NASA Astrophysics Data System (ADS)

Sarkar, Chinmoy; Sinha, Vinayak; Kumar, Vinod; Rupakheti, Maheswar; Panday, Arnico; Mahata, Khadak S.; Rupakheti, Dipesh; Kathayat, Bhogendra; Lawrence, Mark G.

2016-03-01

The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012-2013, a comprehensive study was carried out to characterise the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs, by deploying a proton transfer reaction time-of-flight mass spectrometer (PTR-TOF-MS) - the first such deployment in South Asia. In the study, 71 ion peaks (for which measured ambient concentrations exceeded the 2σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m / Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The concentration ranking in the average VOC mixing ratios during our wintertime deployment was acetaldehyde (8.8 ppb) > methanol (7.4 ppb) > acetone + propanal (4.2 ppb) > benzene (2.7 ppb) > toluene (1.5 ppb) > isoprene (1.1 ppb) > acetonitrile (1.1 ppb) > C8-aromatics ( ˜ 1 ppb) > furan ( ˜ 0.5 ppb) > C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m / z = 69.070) and furan (m / z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde ( ˜ 9 ppb), acetonitrile ( ˜ 1 ppb) and isoprene ( ˜ 1 ppb) to be among the highest reported to date. Two "new" ambient compounds, namely formamide (m / z = 46.029) and acetamide (m / z = 60.051), which can photochemically produce isocyanic acid in the atmosphere, are reported in this study along with nitromethane (a tracer for diesel exhaust), which has only recently been detected in ambient studies. Two distinct periods were selected during the campaign for detailed analysis: the first was associated with high wintertime emissions of biogenic isoprene and the second with elevated levels of ambient acetonitrile, benzene and isocyanic acid from biomass burning activities. Emissions from biomass burning and biomass co-fired brick kilns were found to be the dominant sources for compounds such as propyne, propene, benzene and propanenitrile, which correlated strongly with acetonitrile (r2 > 0.7), a chemical tracer for biomass burning. The calculated total VOC OH reactivity was dominated by acetaldehyde (24.0 %), isoprene (20.2 %) and propene (18.7 %), while oxygenated VOCs and isoprene collectively contributed to more than 68 % of the total ozone production potential. Based on known secondary organic aerosol (SOA) yields and measured ambient concentrations in the Kathmandu Valley, the relative SOA production potential of VOCs were benzene > naphthalene > toluene > xylenes > monoterpenes > trimethylbenzenes > styrene > isoprene. The first ambient measurements from any site in South Asia of compounds with significant health effects such as isocyanic acid, formamide, acetamide, naphthalene and nitromethane have been reported in this study. Our results suggest that mitigation of intense wintertime biomass burning activities, in particular point sources such biomass co-fired brick kilns, would be important to reduce the emission and formation of toxic VOCs (such as benzene and isocyanic acid) in the Kathmandu Valley.

Air quality simulation over South Asia using Hemispheric Transport of Air Pollution version-2 (HTAP-v2) emission inventory and Model for Ozone and Related chemical Tracers (MOZART-4)

NASA Astrophysics Data System (ADS)

Surendran, Divya E.; Ghude, Sachin D.; Beig, G.; Emmons, L. K.; Jena, Chinmay; Kumar, Rajesh; Pfister, G. G.; Chate, D. M.

2015-12-01

This study presents the distribution of tropospheric ozone and related species for South Asia using the Model for Ozone and Related chemical Tracers (MOZART-4) and Hemispheric Transport of Air Pollution version-2 (HTAP-v2) emission inventory. The model present-day simulated ozone (O3), carbon monoxide (CO) and nitrogen dioxide (NO2) are evaluated against surface-based, balloon-borne and satellite-based (MOPITT and OMI) observations. The model systematically overestimates surface O3 mixing ratios (range of mean bias about: 1-30 ppbv) at different ground-based measurement sites in India. Comparison between simulated and observed vertical profiles of ozone shows a positive bias from the surface up to 600 hPa and a negative bias above 600 hPa. The simulated seasonal variation in surface CO mixing ratio is consistent with the surface observations, but has a negative bias of about 50-200 ppb which can be attributed to a large part to the coarse model resolution. In contrast to the surface evaluation, the model shows a positive bias of about 15-20 × 1017 molecules/cm2 over South Asia when compared to satellite derived CO columns from the MOPITT instrument. The model also overestimates OMI retrieved tropospheric column NO2 abundance by about 100-250 × 1013 molecules/cm2. A response to 20% reduction in all anthropogenic emissions over South Asia shows a decrease in the anuual mean O3 mixing ratios by about 3-12 ppb, CO by about 10-80 ppb and NOX by about 3-6 ppb at the surface level. During summer monsoon, O3 mixing ratios at 200 hPa show a decrease of about 6-12 ppb over South Asia and about 1-4 ppb over the remote northern hemispheric western Pacific region.

Ozone Induced Premature Mortality and Crop Yield Loss in China

NASA Astrophysics Data System (ADS)

Lin, Y.; Jiang, F.; Wang, H.

2017-12-01

Exposure to ambient ozone is a major risk factor for health impacts such as chronic obstructive pulmonary disease (COPD) and cause damage to plant and agricultural crops. But these impacts were usually evaluated separately in earlier studies. We apply Community Multi-scale Air Quality model to simulate the ambient O3 concentration at a resolution of 36 km×36 km across China. Then, we follow Global Burden of Diseases approach and AOT40 (i.e., above a threshold of 40 ppb) metric to estimate the premature mortalities and yield losses of major grain crops (i.e., winter wheat, rice and corn) across China due to surface ozone exposure, respectively. Our results show that ozone exposure leads to nearly 67,700 premature mortalities and 145 billion USD losses in 2014. The ozone induced yield losses of all crop production totaled 78 (49.9-112.6)million metric tons, worth 5.3 (3.4-7.6)billion USD, in China. The relative yield losses ranged from 8.5-14% for winter wheat, 3.9-15% for rice, and 2.2-5.5% for maize. We can see that the top four health affected provinces (Sichuan, Henan, Shandong, Jiangsu) are also ranking on the winter wheat and rice crop yield loss. Our results provide further evidence that surface ozone pollution is becoming urgent air pollution in China, and have important policy implications for China to alleviate the impacts of air pollution.

Major 20th century changes of water-soluble humic-like substances (HULISWS) aerosol over Europe inferred from Alpine ice cores

NASA Astrophysics Data System (ADS)

Guilhermet, J.; Preunkert, S.; Voisin, D.; Baduel, C.; Legrand, M.

2013-05-01

Using a newly developed method dedicated to measurements of water-soluble humic-like substances (HULISWS) in atmospheric aerosol samples, the carbon mass quantification of HULISWS in an Alpine ice core is achieved for the first time. The method is based on the extraction of HULISWS with a weak anion-exchanger resin and the subsequent quantification of the extracted carbon fraction with a total organic carbon (TOC) analyzer. Measurements were performed along a Col du Dôme (4250 m above sea level, French Alps) ice core covering the 1920-2004 time period. The HULISWS concentrations exhibit a well-marked seasonal cycle with winter minima close to 7 ppbC and summer maxima ranging between 10 and 50 ppbC. Whereas the winter HULISWS concentrations remained unchanged over the twentieth century, the summer concentrations increased from 20 ppbC prior to the Second World War to 35 ppbC in the 1970-1990s. These different trends reflect the different types of HULISWS sources in winter and summer. HULISWS are mainly primarily emitted by domestic wood burning in winter and secondary in summer being produced from biogenic precursors. For unknown reason, the HULISWS signal is found to be unusual in ice samples corresponding to World War II.

Proton transfer reaction mass spectrometry: on-line trace gas analysis at the ppb level

NASA Astrophysics Data System (ADS)

Hansel, A.; Jordan, A.; Holzinger, R.; Prazeller, P.; Vogel, W.; Lindinger, W.

1995-11-01

A system for trace gas analysis using proton transfer reaction mass spectrometry (PTR-MS) has been developed which allows for on-line measurements of components with concentrations as low as 1 ppb. The method is based on reactions of H3O+ ions, which perform non-dissociative proton transfer to most of the common organic trace constituents but do not react with any of the components present in clean air. Examples of analysis of breath taken from smokers and non-smokers as well as from patients suffering from cirrhosis of the liver, and of air in buildings as well as of ambient air taken at a road crossing demonstrate the wide range of applicability of this method. An enhanced level of acetonitrile in the breath is a most suitable indicator that a person is a smoker. Enhanced levels of propanol strongly indicate that a person has a severe liver deficiency.

Chronic respiratory effects of indoor formaldehyde exposure

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krzyzanowski, M.; Quackenboss, J.J.; Lebowitz, M.D.

The relation of chronic respiratory symptoms and pulmonary function to formaldehyde (HCHO) in homes was studied in a sample of 298 children (6-15 years of age) and 613 adults. HCHO measurements were made with passive samplers two one-week periods. Data on chronic cough and phlegm, wheeze, attacks of breathlessness, and doctor diagnoses of chronic bronchitis and asthma were collected with self-completed questionnaires. Peak expiratory flow rates (PEFR) were obtained during the evenings and mornings for up to 14 consecutive days for each individual. Significantly greater prevalence rates of asthma and chronic bronchitis were found in children from houses with HCHOmore » levels 60-120 ppb than in those less exposed, especially in children also exposed to environmental tobacco smoke. In children, levels of PEFR linearly decreased with HCHO exposure, with estimated decrease due to 60 ppb of HCHO equivalent to 22% of PEFR level in nonexposed children.« less

Biological data on PCBs in animals other than man

USGS Publications Warehouse

Stickel, L.F.

1972-01-01

SUMMARY: Polychlorinated biphenyls have become ubiquitous in the world ecosystem in quantities similar to those of DDE. Experimental studies have shown that PCBs have a toxicity to mallards, pheasants, bobwhite quail, coturnix quail, red-winged blackbirds, starlings, cowbirds, and grackles that is of the same order as the toxicity of DDE to these species. Overt signs of poisoning also are similar to those caused by compounds of the DDT group. Toxic effects of DDE and Aroclor 1254 to coturnix chicks were additive, but not synergistic. PCBs containing higher percentages of chlorine are more toxic to birds than those containing lower percentages. PCBs of foreign manufacture contained contaminants to an extent that greatly increased their toxicity. Residues of PCBs in the brains of birds killed by these compounds measure in the hundreds of parts per million. PCBs may have contributed to mortality of some birds in the field. Toxicity to insects of PCBs of different degrees of chlorination is the reverse of the pattern in birds: the lower chlorinations are more toxic to insects. PCBs enhanced the toxicity of dieldrin and DDT to insects. Shrimp are very sensitive to PCBs and most will die as a result of 20-day exposure to a concentration of 5 ppb. PCBs also inhibit shell growth of oysters. Crabs are less sensitive; all accumulate residues to many times the concentrations in the water, and a test with crabs showed that they lost the residues very slowly. Growth of certain species of marine diatoms was experimentally inhibited by PCBs, but algae were not affected. The small marine crustacean, Gammarus, is sensitive to PCBs in concentrations of thousandths to tenths of a part per billion. Exposure to 5 ppb of Aroclor 1254 caused mortality of two species of fish in 14-45 days. Onset of death was delayed and was accompanied by fungus-like lesions. Rainbow trout were quickly killed by terphenyls at 10 ppb under normal oxygen conditions and at 2 ppb with reduced oxygen. Metabolic changes of PCBs have been suggested by environmental observations of different isomeric patterns in animals of different trophic levels. Quantitative differences also are pronounced, with magnifications of hundreds to thousands of times. Laboratory studies have shown no metabolic changes of PCBs by crabs and shrimps, minimal changes by fish, and pronounced changes by birds. PCBs induce microsomal enzyme activity in birds. Exposure to PCBs increased the susceptibility of mallard ducklings to duck hepatitis virus. Offspring of pheasants whose parents received high dosages of PCBs made poor choices in visual cliff tests. Egg production and hatching after pipping also were affected. Migratory restlessness was increased in English robins exposed to PCBs. Long-term studies of the reproductive effects of Aroclor 1254 on mallards and bobwhite quail and of Aroclor 1254 plus DDE on quail showed no significant differences from controls. In studies of chickens, however, egg production and hatchability were impaired by high doses of Aroclor 1254 and by low doses of Aroclor 1242. Statistical evaluations of the role that different chemicals may play in thinning eggshells of brown pelicans showed that DDE residues correlate better with shell thinning than do residues of dieldrin or PCBs, confirming observations with cormorants and white pelicans.

Wintertime Methane and Non-Methane Hydrocarbon Measurements Utah's Uintah Basin

NASA Astrophysics Data System (ADS)

Martin, R. S.

2012-12-01

As a part of the winter 2011/2012 Uintah Basin Winter Ozone Study, ambient methane (CH4) and total non-methane hydrocarbons (TNMHC) were measured at a population center (Roosevelt) and within the oil/gas field (Horse Pool). At Horse Pool, near real-time CH4/TNMHC were monitored using a GC-FID analyzer. Samples were collected for 30 seconds once every five minutes. The TNMHC concentrations were reported in ppb-C3, or parts per billion in C3 (propane) equivalents. At Roosevelt, discrete volatile organic carbon (VOC) samples were collected for two weeks beginning on Feb. 14, 2012 using evacuated stainless steel Summa canisters. The samples were collected over four 1-hr time periods spaced throughout the day. After collection, the canisters were shipped to a commercial laboratory for GC-MS quantification. Methane samples were obtained at Roosevelt by whole vial collection and subsequently analyzed via GC-FID. Nominally, the CH4 vials were collected at the start and end of each canister collection period, as well as intermittently throughout the daily periods. Furthermore, CH4 grab samples were collected at several other locations throughout the Basin when possible. For the full wintertime study period (Jan. 19 - Mar. 15, 2012), the CH4 and TNMHC at Horse Pool averaged 3.47±1.8 ppm and 243±253 ppb-C3 (± 1σ), respectively. A very strong diurnal behavior was seen for both classes of compounds, with CH4 maximums approaching 30 ppm in the early morning hours. During the comparative February time period, CH4 concentrations at Horse Pool averaged 3.25±0.07 ppm (± 95% CI), while CH4 at Roosevelt averaged 2.52±0.08 ppm. No strong diurnal behavior was observed at Roosevelt and the maximum CH4 levels only reached 4.08 ppm. Grab samples from the other locations found similar or slightly lower CH4 concentrations, with the exception of Ouray (3.91±1.27 ppm) which was also located in the production/exploration area, but was among the lowest elevation of the sampling sites. It was also observed at Horse Pool that the relationship between CH4 and TNMHC showed a strong function of wind direction. When the winds were out of the northwest the ratio of TNMHC to CH4 was about 185, whereas when the wind was from any other sector the ratio decreased to around 80. Tedlar bag grab samples collected from arrayed locations surrounding Horse Pool verified the wind sector-dependent ratio function, indicating two separate regional source signatures. Examination of well-type locations suggested that these differing regimes may be due to the spatial delineation between predominantly oil or gas wells. Direct comparison of TNMHC between Roosevelt and Horse Pool was not possible because the commercial analysis was unable to identify VOCS with fewer than three carbons and parallel investigators (J. Gillman; NOAA-CSD) observed that these were significant at Horse Pool. Recalling that the averaged TNMHC at Horse Pool was 243 ppb-C3, it should be noted that of the compounds identified at Roosevelt only four (propane, isobutene, n-butane, and n-pentane) were observed at concentrations greater than 1.0 ppb. These species are often associated with urban or traffic areas, as opposed to oil and gas fields. Additionally, examination of the relationships between other typical urban VOCs (BTEX), their ratios also suggest sources associated with urban, traffic dominated plumes.

Single microfilaments mediate the early steps of microtubule bundling during preprophase band formation in onion cotyledon epidermal cells

PubMed Central

Takeuchi, Miyuki; Karahara, Ichirou; Kajimura, Naoko; Takaoka, Akio; Murata, Kazuyoshi; Misaki, Kazuyo; Yonemura, Shigenobu; Staehelin, L. Andrew; Mineyuki, Yoshinobu

2016-01-01

The preprophase band (PPB) is a cytokinetic apparatus that determines the site of cell division in plants. It originates as a broad band of microtubules (MTs) in G2 and narrows to demarcate the future division site during late prophase. Studies with fluorescent probes have shown that PPBs contain F-actin during early stages of their development but become actin depleted in late prophase. Although this suggests that actins contribute to the early stages of PPB formation, how actins contribute to PPB-MT organization remains unsolved. To address this question, we used electron tomography to investigate the spatial relationship between microfilaments (MFs) and MTs at different stages of PPB assembly in onion cotyledon epidermal cells. We demonstrate that the PPB actins observed by fluorescence microscopy correspond to short, single MFs. A majority of the MFs are bound to MTs, with a subset forming MT-MF-MT bridging structures. During the later stages of PPB assembly, the MF-mediated links between MTs are displaced by MT-MT linkers as the PPB MT arrays mature into tightly packed MT bundles. On the basis of these observations, we propose that the primary function of actins during PPB formation is to mediate the initial bundling of the PPB MTs. PMID:27053663

Carbonyl compounds in dining areas, kitchens and exhaust streams in restaurants with varying cooking methods in Kaohsiung, Taiwan.

PubMed

Cheng, Jen-Hsuan; Lee, Yi-Shiun; Chen, Kang-Shin

2016-03-01

Eighteen carbonyl species in C1-C10 were measured in the dining areas, kitchens and exhaust streams of six different restaurant types in Kaohsiung, southern Taiwan. Measured results in the dining areas show that Japanese barbecue (45.06ppb) had the highest total carbonyl concentrations (sum of 18 compounds), followed by Chinese hotpot (38.21ppb), Chinese stir-frying (8.99ppb), Western fast-food (8.22ppb), Chinese-Western mixed style (7.38ppb), and Chinese buffet (3.08ppb), due to their different arrangements for dining and cooking spaces and different cooking methods. On average, low carbon-containing species (C1-C4), e.g., formaldehyde, acetaldehyde, acetone and butyraldehyde were dominant and contributed 55.01%-94.52% of total carbonyls in the dining areas of all restaurants. Meanwhile, Chinese-Western mixed restaurants (45.48ppb) had high total carbonyl concentrations in kitchens mainly because of its small kitchen and poor ventilation. However, high carbon-containing species (C5-C10) such as hexaldehyde, heptaldehyde and nonanaldehyde (16.62%-77.00% of total carbonyls) contributed comparatively with low carbon-containing compounds (23.01%-83.39% of total carbonyls) in kitchens. Furthermore, Chinese stir-frying (132.10ppb), Japanese barbecue (125.62ppb), Western fast-food (122.67ppb), and Chinese buffet (119.96ppb) were the four restaurant types with the highest total carbonyl concentrations in exhaust streams, indicating that stir-frying and grilling are inclined to produce polluted gases. Health risk assessments indicate that Chinese hotpot and Japanese barbecue exceeded the limits of cancer risk (10(-6)) and hazard index (=1), mainly due to high concentrations of formaldehyde. The other four restaurants were below both limits. Copyright © 2015. Published by Elsevier B.V.

Technical Report for Water Circulation Pumping System for Trihalomethanes (THMs)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bellah, W.

2015-06-08

The TSWWS was added as an active source of supply to the permit (No. 03-10-13P-003) in 2010, but has never been used due to the potential for formation of trihalomethanes (THMs) in the distribution system. THMs are formed as a by-product when chlorine is used to disinfect water for drinking. THMs are a group of chemicals generally referred to as disinfection by-products (DBPs). THMs result from the reaction of chlorine with organic matter that is present in the water. Some of the THMs are volatile and may easily vaporize into the air. This fact forms the basis of the designmore » of the system discussed in this technical report. In addition, the design is based on the results of a study that has shown success using aeration as a means to reduce TTHMs to within allowable concentration levels with turn-over times as long as ten days. The Primary Drinking Water Standards of Regulated Contaminants Maximum Contaminant Level (MCL) for TTHMs is 80 parts per billion (ppb). No other changes to the existing drinking water distribution system and chlorination operations are anticipated before switching to the TSWWS as the primary drinking water source. The two groundwater wells (Wells 20 and 18) which are currently the primary and backup water sources for the system would be maintained for use as backup supply. In the future, one of the wells may be removed from the system. A permit amendment would be filed at that time if this modification was deemed appropriate.« less