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Sample records for acute dietary exposure

  1. Factors affecting the estimated probabilistic acute dietary exposure to captan from apple consumption.

    PubMed

    Zentai, A; Sali, J; Szabó, I J; Szeitzné-Szabó, M; Ambrus, A; Vásárhelyi, A

    2013-01-01

    The effect of the number of pesticide residue values below the LOQ/LOD of analytical methods, the variability of residues in individual fruits, mass of fruit units and the number of bootstrap iterations was studied on the probabilistically estimated acute exposure of consumers. The 4720 daily apple consumption data and the results of 1239 apple sample analyses for captan residues, performed within the Hungarian monitoring programme between 2005 and 2011, were used in this study as model matrix. Up to about 95th percentile exposure (µg/(kg bw·day)), simply multiplying each residue in composite samples with each consumption value gave similar estimates to those obtained with the complex procedure taking also into account the mass of and residues in individual fruits. However, the exposure above the 95th percentile calculated with the complex procedure gradually increased with increasing percentile level compared to the simple procedure. Including the high number of non-detects reduced the estimated exposure, which was the highest when only the residues measured in treated fruits were taken into account. The number of bootstrap iterations between 100 and 10,000 did not significantly affect the calculated exposure. The 99.99th percentile exposure amounted to 17.9% of the acute reference dose of 300 µg/(kg bw·day) for women of childbearing age.

  2. Probabilistic acute dietary exposure assessment of the Chinese population to cypermethrin residues.

    PubMed

    Sun, J-F; Liu, P; Li, C-Y; Li, J-X; Wang, C-N; Min, J; Hu, D; Wu, Y-N

    2011-01-01

    A probabilistic estimation of dietary exposure to cypermethrin residues for the Chinese population was performed. Cypermethrin residue data were obtained from the national food contamination monitoring program for 2001-2006, encompassing 14,096 samples from 36 commodities with a detection rate of 10.4%. Food consumption data were gathered from the national nutrition and health survey conducted in 2002, comprising 65,915 consumers aged 2-100 years and 3701 children of 2-6 years old. The whole country was roughly divided into six regions and the ranges of the median and of P99.9 exposure estimated for these regions were 0.018-0.026 and 3.131-7.095 µg kg(-1 )bw day(-1), respectively. Pak-choi and Chinese cabbage contributed 33.9 and 13.2%, respectively, to the cypermethrin intake for the general population, while pak-choi and citrus covered 30.7 and 22.5% of the total intake for children, respectively. The exposure of the rural population was higher than urban populations. Rural areas mainly located in the plains of central China had among the highest exposure of the six regions, accounting for 17.7% of the ARfD at P99.9, while the 99.99th percentile of exposure for children, especially rural children, far exceeded the ARfD, which is a cause for concern.

  3. Probabilistic acute dietary exposure assessments to captan and tolylfluanid using several European food consumption and pesticide concentration databases.

    PubMed

    Boon, Polly E; Svensson, Kettil; Moussavian, Shahnaz; van der Voet, Hilko; Petersen, Annette; Ruprich, Jiri; Debegnach, Francesca; de Boer, Waldo J; van Donkersgoed, Gerda; Brera, Carlo; van Klaveren, Jacob D; Busk, Leif

    2009-12-01

    Probabilistic dietary acute exposure assessments of captan and tolylfluanid were performed for the populations of the Czech Republic, Denmark, Italy, the Netherlands and Sweden. The basis for these assessments was national databases for food consumption and pesticide concentration data harmonised at the level of raw agricultural commodity. Data were obtained from national food consumption surveys and national monitoring programmes and organised in an electronic platform of databases connected to probabilistic software. The exposure assessments were conducted by linking national food consumption data either (1) to national pesticide concentration data or (2) to a pooled database containing all national pesticide concentration data. We show that with this tool national exposure assessments can be performed in a harmonised way and that pesticide concentrations of other countries can be linked to national food consumption surveys. In this way it is possible to exchange or merge concentration data between countries in situations of data scarcity. This electronic platform in connection with probabilistic software can be seen as a prototype of a data warehouse, including a harmonised approach for dietary exposure modelling.

  4. NEUROCHEMICAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL ACUTE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    Lots of information is available surrounding the acute toxicity of anticholinesterase pesticides, but these have been very few detailed studies on the chronic effects of these pesticides. Humans are exposed on a chronic basis and some humans believe that have been affected advers...

  5. Acute and chronic dietary exposure to domoic acid in recreational harvesters: A survey of shellfish consumption behavior.

    PubMed

    Ferriss, Bridget E; Marcinek, David J; Ayres, Daniel; Borchert, Jerry; Lefebvre, Kathi A

    2017-04-01

    Domoic acid (DA) is a neurotoxin that is naturally produced by phytoplankton and accumulates in seafood during harmful algal blooms. As the prevalence of DA increases in the marine environment, there is a critical need to identify seafood consumers at risk of DA poisoning. DA exposure was estimated in recreational razor clam (Siliqua patula) harvesters to determine if exposures above current regulatory guidelines occur and/or if harvesters are chronically exposed to low levels of DA. Human consumption rates of razor clams were determined by distributing 1523 surveys to recreational razor clam harvesters in spring 2015 and winter 2016, in Washington, USA. These consumption rate data were combined with DA measurements in razor clams, collected by a state monitoring program, to estimate human DA exposure. Approximately 7% of total acute exposures calculated (including the same individuals at different times) exceeded the current regulatory reference dose (0.075mgDA·kgbodyweight(-1)·d(-1)) due to higher than previously reported consumption rates, lower bodyweights, and/or by consumption of clams at the upper range of legal DA levels (maximum 20mg·kg(-1) wet weight for whole tissue). Three percent of survey respondents were potentially at risk of chronic DA exposure by consuming a minimum of 15 clams per month for at 12 consecutive months. These insights into DA consumption will provide an additional tool for razor clam fishery management.

  6. Probabilistic acute risk assessment of cumulative exposure to organophosphorus and carbamate pesticides from dietary vegetables and fruits in Shanghai populations.

    PubMed

    Li, Fan; Yuan, Yaqun; Meng, Pai; Wu, Min; Li, Shuguang; Chen, Bo

    2017-02-03

    Organophosphorus pesticides (OPs) and carbamate pesticides (CPs) are among the most widely used pesticides in China, playing a major role in protecting agricultural commodities. In this study, we determined the cumulative acute exposure to OPs and CPs of Shanghai residents from vegetables and fruits (VFs). The food consumption data were obtained from the Shanghai Food Consumption Survey (SHFCS) of 2012-14 including a total of 1973 participants aged 2-90 years. The pesticide residue data were obtained from the Shanghai monitoring programme during 2008-11 with 34 organophosphates and 11 carbamates analysed in a total of 5335 samples of VFs. A probabilistic approach was performed as recommended by the EFSA, using the optimistic model with non-detects set as zero and with processing factors (PFs) being used and the pessimistic model with non-detects replaced by limit of detection (LOD) and without PFs. We used the relative potency factor (RPF) method to normalise the various pesticides to the index compound (IC) of methamidophos and chlorpyrifos separately. Only in the pessimistic model using methamidophos as the IC was there was small risk of exposure exceeding the ARfD (3 µg kg(-)(1) bw day(-)(1)) in the populations of preschool children (0.029%), school-age children (0.022%) and adults (0.002%). There were no risk of exposure exceeding the ARfD of methamidophos in the optimistic model and of chlorpyrifos (100 µg kg(-)(1) bw day(-)(1)) in both optimistic and pessimistic models in all three populations. Considering the Chinese habits of overwhelmingly eating processed food (vegetables being cooked, and fruits being washed or peeled), we conclude that little acute risk was found for the exposure to VF-sourced OPs and CPs in Shanghai.

  7. CHILDREN'S DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    The Food Quality Protection Act of 1996 requires EPA to more accurately assess children's aggregate exposures to environmental contaminants. Children have unstructured eating behaviors which cause excess exposures as a result of their activities. Determining total dietary intak...

  8. CHILDREN'S DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    The Food Quality Protection Act of 1996 requires EPA to more accurately assess children's aggregate exposures to environmental contaminants. Children have unstructured eating behaviors which cause excess exposures as a result of their activities. Determining total dietary intak...

  9. Risks from occupational and dietary exposure to mevinphos.

    PubMed

    Cochran, R C; Formoli, T A; Silva, M H; Kellner, T P; Lewis, C M; Pfeifer, K F

    1996-01-01

    Mevinphos (trade name, Phosdrin), a category 1 organophosphorus insecticide, has been used mainly as a cleanup pesticide for vegetable crops. A risk assessment for occupational and dietary exposure to mevinphos was initiated because of the high acute toxicity of the compound. Repetitive dosing with mevinphos did not cause any discernible histopathological effects in mice or rats, nor was it oncogenic in either species. The principal toxic effects of mevinphos, both short- and long term, were due to inhibition of cholinesterase activity. Consequently, potential adverse effects from short-term exposures were the primary concern. A human no-observed-effect level (0.025 mg/kg) for cholinergic signs was used as the regulatory basis for calculating margins of safety (MOSs) for potential acute dietary and short-term occupational exposures. Estimates of exposure to mixer/loaders, pilots, and flaggers associated with aerial application of mevinphos were based on passive dosimetry. Because no acceptable exposure studies for work tasks associated with ground application of mevinphos were available, surrogate data based on ground application of oxydemeton-methyl were used. Exposure estimates for field workers and harvesters relied on measured dislodgeable foliar residues of mevinphos and transfer factors generated from studies of other active ingredients. MOSs for mean acute occupational exposure of mixer/loader/applicators associated with ground application and of harvesters working in fruit trees were less than the value conventionally recommended to protect people from the toxic effects of mevinphos. MOSs for the 95th percentile of short-term worker exposure for all mixer/loader work categories associated with mevinphos application were also inadequate. Calculated MOSs for potential acute dietary exposure to measured residue levels of mevinphos were adequate for the various population subgroups. However, 25 of the USEPA tolerances for mevinphos on agricultural commodities

  10. RECENT ENHANCEMENTS TO THE DIETARY EXPOSURE POTENTIAL MODEL

    EPA Science Inventory

    Presentation describes recent enhancements & new applications of the Dietary Exposure Potential Model (DEPM), a model developed to assist in design & interpretation of dietary exposure measurements. Model is an interactive system that provides dietary exposure estimates using dat...

  11. RECENT ENHANCEMENTS TO THE DIETARY EXPOSURE POTENTIAL MODEL

    EPA Science Inventory

    Presentation describes recent enhancements & new applications of the Dietary Exposure Potential Model (DEPM), a model developed to assist in design & interpretation of dietary exposure measurements. Model is an interactive system that provides dietary exposure estimates using dat...

  12. DERMAL AND NON-DIETARY EXPOSURE WORKSHOP

    EPA Science Inventory

    A dermal and non-dietary ingestion exposure workshop was sponsored by U.S. EPA's National Exposure Research Laboratory (NERL) on September 17,1998. The purpose of this workshop was to gather information on the state-of-the-art in measuring and assessing children's exposures to ...

  13. DEVELOPMENT OF A DIETARY EXPOSURE POTENTIAL MODEL FOR EVALUATING DIETARY EXPOSURE TO CHEMICAL RESIDUES IN FOOD

    EPA Science Inventory

    The Dietary Exposure Potential Model (DEPM) is a computer-based model developed for estimating dietary exposure to chemical residues in food. The DEPM is based on food consumption data from the 1987-1988 Nationwide Food Consumption Survey (NFCS) administered by the United States ...

  14. DEVELOPMENT OF A DIETARY EXPOSURE POTENTIAL MODEL FOR EVALUATING DIETARY EXPOSURE TO CHEMICAL RESIDUES IN FOOD

    EPA Science Inventory

    The Dietary Exposure Potential Model (DEPM) is a computer-based model developed for estimating dietary exposure to chemical residues in food. The DEPM is based on food consumption data from the 1987-1988 Nationwide Food Consumption Survey (NFCS) administered by the United States ...

  15. ESTIMATING EXCESS DIETARY EXPOSURES OF YOUNG CHILDREN

    EPA Science Inventory

    Nine children in a daycare that routinely applied the pesticide, esfenvalerate, were studied to assess excess dietary exposures. Surface wipes, a standard food item of processed American cheese slice pressed on the surface and handled by the child, an accelerometer reading, and ...

  16. MEASURING DIETARY EXPOSURE OF YOUNG CHILDREN

    EPA Science Inventory

    Young children do not consume foods in a structured manner. Their foods contact surfaces (hands, floors, eating surfaces, etc.) that may be contaminated while they are eating them. Thus, dietary exposures of young children are difficult to accurately assess or measure. A recen...

  17. ESTIMATING EXCESS DIETARY EXPOSURES OF YOUNG CHILDREN

    EPA Science Inventory

    Nine children in a daycare that routinely applied the pesticide, esfenvalerate, were studied to assess excess dietary exposures. Surface wipes, a standard food item of processed American cheese slice pressed on the surface and handled by the child, an accelerometer reading, and ...

  18. DIETARY EXPOSURES OF YOUNG CHILDREN, PART 3: MODELLING

    EPA Science Inventory

    A deterministic model was used to model dietary exposure of young children. Parameters included pesticide residue on food before handling, surface pesticide loading, transfer efficiencies and children's activity patterns. Three components of dietary pesticide exposure were includ...

  19. DIETARY EXPOSURES OF YOUNG CHILDREN, PART 3: MODELLING

    EPA Science Inventory

    A deterministic model was used to model dietary exposure of young children. Parameters included pesticide residue on food before handling, surface pesticide loading, transfer efficiencies and children's activity patterns. Three components of dietary pesticide exposure were includ...

  20. ADVANCES IN DIETARY EXPOSURE RESEARCH AT THE UNITED STATES

    EPA Science Inventory

    The United States Environmental Protection Agency-National Exposure Research Laboratory's (USEPA-NERL)dietary exposure research program investigates the role of diet, including drinking water, as a potential pathway of human exposure to environmental contaminants. A primary progr...

  1. Dietary phosphorus acutely impairs endothelial function.

    PubMed

    Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji

    2009-07-01

    Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality.

  2. Dietary Phosphorus Acutely Impairs Endothelial Function

    PubMed Central

    Shuto, Emi; Taketani, Yutaka; Tanaka, Rieko; Harada, Nagakatsu; Isshiki, Masashi; Sato, Minako; Nashiki, Kunitaka; Amo, Kikuko; Yamamoto, Hironori; Higashi, Yukihito; Nakaya, Yutaka; Takeda, Eiji

    2009-01-01

    Excessive dietary phosphorus may increase cardiovascular risk in healthy individuals as well as in patients with chronic kidney disease, but the mechanisms underlying this risk are not completely understood. To determine whether postprandial hyperphosphatemia may promote endothelial dysfunction, we investigated the acute effect of phosphorus loading on endothelial function in vitro and in vivo. Exposing bovine aortic endothelial cells to a phosphorus load increased production of reactive oxygen species, which depended on phosphorus influx via sodium-dependent phosphate transporters, and decreased nitric oxide production via inhibitory phosphorylation of endothelial nitric oxide synthase. Phosphorus loading inhibited endothelium-dependent vasodilation of rat aortic rings. In 11 healthy men, we alternately served meals containing 400 mg or 1200 mg of phosphorus in a double-blind crossover study and measured flow-mediated dilation of the brachial artery before and 2 h after the meals. The high dietary phosphorus load increased serum phosphorus at 2 h and significantly decreased flow-mediated dilation. Flow-mediated dilation correlated inversely with serum phosphorus. Taken together, these findings suggest that endothelial dysfunction mediated by acute postprandial hyperphosphatemia may contribute to the relationship between serum phosphorus level and the risk for cardiovascular morbidity and mortality. PMID:19406976

  3. Indirect Dietary Residential Exposure Assessment Model (IDREAM) Implementation

    EPA Pesticide Factsheets

    The Indirect Dietary Residential Exposure Assessment Model (IDREAM) estimates indirect ingestion exposure to disinfectants used in residential settings on hard surfaces where there may be inadvertent transfer to edible items prepared on those surfaces.

  4. EXPOSURE OF RAINBOW TROUT TO DIETARY METALS USING LIVE PREY

    EPA Science Inventory

    Dietary exposure to CD, Cu, ZN, and Pb has been shown to cause accumulatioin of metal in fish and other aquatic organisms...In this study the toxicity of dietary metal exposure was evaluated using an experimental food chain of sediment from oligochaetes to fish...Relationships am...

  5. DIETARY EXPOSURE TO PYRETHROIDS IN THE U.S POPULATION

    EPA Science Inventory

    We examined the contribution of pyrethroid residues in food as an important driver of exposure. The levels of urinary metabolites of pyrethroids reported in NHANES were used as a general estimate of population exposure to pyrethroids. Dietary exposure to pyrethroids was estimat...

  6. DIETARY EXPOSURE TO PYRETHROIDS IN THE U.S POPULATION

    EPA Science Inventory

    We examined the contribution of pyrethroid residues in food as an important driver of exposure. The levels of urinary metabolites of pyrethroids reported in NHANES were used as a general estimate of population exposure to pyrethroids. Dietary exposure to pyrethroids was estimat...

  7. DIETARY EXPOSURES OF YOUNG CHILDREN, PART II: FIELD STUDY

    EPA Science Inventory

    A small, pilot field study was conducted to determine the adequacy of protocols for dietary exposure measurements. Samples were collected to estimate the amount of pesticides transferred from contaminated surfaces or hands to foods of young children and to validate a dietary mod...

  8. DIETARY EXPOSURES OF YOUNG CHILDREN, PART II: FIELD STUDY

    EPA Science Inventory

    A small, pilot field study was conducted to determine the adequacy of protocols for dietary exposure measurements. Samples were collected to estimate the amount of pesticides transferred from contaminated surfaces or hands to foods of young children and to validate a dietary mod...

  9. U.S. EPA'S ACUTE REFERENCE EXPOSURE METHODOLOGY FOR ACUTE INHALATION EXPOSURES

    EPA Science Inventory

    The US EPA National Center for Environmental Assessment has developed a methodology to derive acute inhalation toxicity benchmarks, called acute reference exposures (AREs), for noncancer effects. The methodology provides guidance for the derivation of chemical-specific benchmark...

  10. Amphetamine Containing Dietary Supplements and Acute Myocardial Infarction

    PubMed Central

    Hritani, Abdulwahab; Antoun, Patrick

    2016-01-01

    Weight loss is one of the most researched and marketed topics in American society. Dietary regimens, medications that claim to boost the metabolism, and the constant pressure to fit into society all play a role in our patient's choices regarding new dietary products. One of the products that are well known to suppress appetite and cause weight loss is amphetamines. While these medications suppress appetite, most people are not aware of the detrimental side effects of amphetamines, including hypertension, tachycardia, arrhythmias, and in certain instances acute myocardial infarction. Here we present the uncommon entity of an acute myocardial infarction due to chronic use of an amphetamine containing dietary supplement in conjunction with an exercise regimen. Our case brings to light further awareness regarding use of amphetamines. Clinicians should have a high index of suspicion of use of these substances when young patients with no risk factors for coronary artery disease present with acute arrhythmias, heart failure, and myocardial infarctions. PMID:27516911

  11. Comprehensive European dietary exposure model (CEDEM) for food additives.

    PubMed

    Tennant, David R

    2016-05-01

    European methods for assessing dietary exposures to nutrients, additives and other substances in food are limited by the availability of detailed food consumption data for all member states. A proposed comprehensive European dietary exposure model (CEDEM) applies summary data published by the European Food Safety Authority (EFSA) in a deterministic model based on an algorithm from the EFSA intake method for food additives. The proposed approach can predict estimates of food additive exposure provided in previous EFSA scientific opinions that were based on the full European food consumption database.

  12. Dietary aflatoxin exposure and chemoprevention of cancer: a clinical review.

    PubMed

    Sudakin, Daniel L

    2003-01-01

    Exposure to dietary aflatoxins is considered to be an important risk factor for the development of hepatocellular carcinoma in certain regions of the world. Significant advances have recently been made in understanding the clinical toxicology of aflatoxins. These include the development and validation of biomarkers of exposure and genotoxic effect. These biomarkers are currently being utilized to explore the potential that pharmaceutical interventions may have in modifying the toxicokinetics of dietary aflatoxin exposure. Preliminary results of clinical trials with the drug oltipraz suggest that it may modify the genotoxic effects of aflatoxin B1 by inhibiting bioactivation pathways and stimulating detoxification pathways. More recent results of a clinical trial with chlorophyllin suggest that this drug may have a role in preventing dietary exposure to aflatoxin B1 by reducing its oral bioavailability. The preliminary results of these chemoprevention studies may ultimately have implications for cancer prevention in high-risk populations in the future.

  13. Household dietary exposure to aflatoxins from maize and maize products in Kenya.

    PubMed

    Kilonzo, Robert M; Imungi, Jasper K; Muiru, William M; Lamuka, Peter O; Njage, Patrick M Kamau

    2014-01-01

    Aflatoxicosis has repeatedly affected Kenyans, particularly in the eastern region, due to consumption of contaminated maize. However, save for the cases of acute toxicity, the levels of sub-lethal exposure have not been adequately assessed. It is believed that this type of exposure does exist even during the seasons when acute toxicity does not occur. This study, therefore, was designed to assess the exposure of households to aflatoxins through consumption of maize and maize products. Twenty samples each of maize kernels, muthokoi and maize meal were randomly sampled from households in Kibwezi District of Makueni County in Eastern Kenya and analysed for aflatoxin contamination. The samples were quantitatively analysed for aflatoxin contamination using HPLC. The uncertainty and variability in dietary exposure was quantitatively modelled in Ms Excel using Monte Carlo simulation in @Risk software. Aflatoxins were found in 45% of maize kernels at between 18 and 480 μg kg⁻¹, 20% of muthokoi at between 12 and 123 μg kg⁻¹, and 35% of maize meal at between 6 and 30 μg kg⁻¹. The mean dietary exposure to aflatoxin in maize kernels was 292 ± 1567 ng kg⁻¹ body weight day⁻¹, while the mean dietary exposure to aflatoxin in maize meal and muthokoi were 59 ± 62 and 27 ± 154 ng kg⁻¹ body weight day⁻¹ respectively. The results showed that the amount and frequency of consumption of the three foods is the more important contributing factor than the mean aflatoxin concentration levels, to the risk of dietary exposure to aflatoxins.

  14. Dietary cadmium exposure assessment among the Chinese population.

    PubMed

    Song, Yan; Wang, Yibana; Mao, Weifeng; Sui, Haixia; Yong, Ling; Yang, Dajin; Jiang, Dingguo; Zhang, Lei; Gong, Yunyun

    2017-01-01

    Cadmium, a toxic heavy metal, is widely present in food. It has been reported that chronic cadmium exposure is associated with kidney disease, osteoporosis, cardiovascular disease and cancer. The aim of this study was to assess the dietary cadmium exposure and potential health risk in different age-sex groups of the Chinese population (children aged 4-11 years, young people aged 12-17 years and adults aged over 18 years), and in the southern and northern population using a semi-probabilistic method. Cadmium was detected in 228,687 food samples from 32 food categrories by graphite furnace atomic absorption spectrometry. The dietary cadmium exposures were estimated by combining the cadmium concentration data with food consumption data derived from the China National Nutrient and Health Survey 2002, and evaluated against the Provisional Tolerable Monthly Intake (PTMI) of 25 μg/kg BW/month established by the Joint FAO/WHO expert committee on food additives (JECFA). The mean dietary cadmium exposure of the general Chinese population (15.3 μg/kg BW/month) was below the PTMI. The high consumer exposures (95th percentile, P95) for the general population and different sub-groups were higher than the PTMI. The dietary cadmium exposure of the southern population was apparently higher than that of the northern population. Rice was the most important contributor to cadmium exposure for Chinese people, especially those living in the southern areas of China. These findings indicated that the health risk from dietary cadmium exposure of the general Chinese people was low, but the health risk of cadmium exposure of certain sub-groups should be of concern.

  15. Health risks of dietary exposure to perfluorinated compounds.

    PubMed

    Domingo, José L

    2012-04-01

    Perfluorinated compounds (PFCs) form a diverse group of chemicals with surface-active properties manufactured for over 50 years. In recent years, a number of studies have reported the ubiquitous distribution of PFCs in human tissues and wildlife. Although the relative importance of the routes of human exposure to these compounds is not well established yet, it has been suggested that food intake and packaging, water, house dust, and airborne are all potentially significant sources. However, dietary intake is probably the main route of exposure to these compounds, including perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA), the most extensively investigated PFCs. This paper reviews the state of the science regarding the concentrations of PFCs in foodstuffs, human dietary exposure to these compounds and their health risks. The influence of processing, cooking and packaging on the PFCs levels in food is also discussed. Because of the rather limited information about human dietary exposure, studies to determine exposure to PFCs through the diet for the general population of a number of countries are clearly necessary. The correlation of PFCs body burdens and dietary intake of PFCs should be also established. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. Exposure apportionment: ranking food items by their contribution to dietary exposure.

    PubMed

    Moschandreas, D J; Karuchit, S; Berry, M R; O'Rourke, M K; Lo, D; Lebowitz, M D; Robertson, G

    2002-07-01

    This paper identifies and ranks food items by estimating their contribution to the dietary exposure of the US population and 19 subpopulation groups. Contributions to dietary exposures to arsenic, cadmium, chromium, lead, nickel, benzene, chlorpyrifos, and diazinon are estimated using either the Dietary Exposure Potential Model (DEPM) approach, the National Human Exposure Assessment Survey Arizona (NHEXAS-AZ) approach or the combination of the two. The DEPM is a computer model that uses several national databases of food consumption and residue concentrations for estimating dietary. The DEPM approach ranks the contribution of food items to the total dietary exposure using two methods, the direct method that ranks contributions by population exposure magnitude and the weighted method that ranks by subpopulation exposure magnitude. The DEPM approach identifies highly exposed subpopulations and a relatively small number of food items contributing the most to dietary exposure. The NHEXAS-AZ approach uses the NHEXAS-AZ database containing food consumption data for each subject and chemical residues of a composite of food items consumed by each subject in 1 day during the sampling week. These data are then modeled to obtain estimates of dietary exposure to chemical residues. The third approach uses the NHEXAS-AZ consumption data with residue values from the national residue database. This approach also estimates percent contributions to exposure of each ranked food item for the Arizona population. Dietary exposures estimated using the three approaches are compared. The DEPM results indicate groups with highest dietary exposures include Nonnursing Infants, Children 1-6, Hispanic, Non-Hispanic White, Western, Northeast and Poverty 0-130%. The use of the Combined National Residue Database (CNRD) identifies 43 food items as primary contributors to total dietary exposure; they contribute a minimum of 68% of the total dietary exposure to each of the eight chemical residues

  17. UNDERSTANDING CHILDREN'S TOTAL DIETARY EXPOSURE TO PESTICIDES

    EPA Science Inventory

    Recent residential monitoring studies have demonstrated that significant portion of total exposure of infants and children to environmental contaminants can result from contamination of food in the home. Children's foods become contaminated through handling and contact with surf...

  18. How EPA Uses Dietary data from USDA for Exposure Assessments

    USDA-ARS?s Scientific Manuscript database

    Background: To present the procedures the US Environmental Protection Agency’s (EPA’s) Office of Pesticide Programs (OPP) uses to update the estimates of dietary exposure to pesticides using the consumption data from the National Health and Nutrition Survey, What We Eat in America and methodology a...

  19. Statistical analysis of a dynamic model for dietary contaminant exposure.

    PubMed

    Bertail, P; Clémençon, S; Tressou, J

    2010-03-01

    This paper is devoted to the statistical analysis of a stochastic model introduced in [P. Bertail, S. Clémençon, and J. Tressou, A storage model with random release rate for modelling exposure to food contaminants, Math. Biosci. Eng. 35 (1) (2008), pp. 35-60] for describing the phenomenon of exposure to a certain food contaminant. In this modelling, the temporal evolution of the contamination exposure is entirely determined by the accumulation phenomenon due to successive dietary intakes and the pharmacokinetics governing the elimination process inbetween intakes, in such a way that the exposure dynamic through time is described as a piecewise deterministic Markov process. Paths of the contamination exposure process are scarcely observable in practice, therefore intensive computer simulation methods are crucial for estimating the time-dependent or steady-state features of the process. Here we consider simulation estimators based on consumption and contamination data and investigate how to construct accurate bootstrap confidence intervals (CI) for certain quantities of considerable importance from the epidemiology viewpoint. Special attention is also paid to the problem of computing the probability of certain rare events related to the exposure process path arising in dietary risk analysis using multilevel splitting or importance sampling (IS) techniques. Applications of these statistical methods to a collection of data sets related to dietary methyl mercury contamination are discussed thoroughly.

  20. DIETARY EXPOSURE OF CHILDREN TO LEAD

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead adsorption occurs more readily in a child as compared to an adult, and 3) the child's development is more vulnerable ...

  1. DIETARY EXPOSURE OF CHILDREN TO LEAD

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because 1) they have more opportunity for contact with lead sources due to their activities, 2) lead adsorption occurs more readily in a child as compared to an adult, and 3) the child's development is more vulnerable ...

  2. Dietary Mutagen Exposure and Risk of Pancreatic Cancer

    PubMed Central

    Li, Donghui; Sue Day, Rena; Bondy, Melissa L.; Sinha, Rashmi; Nguyen, Nga T.; Evans, Douglas B.; Abbruzzese, James L.; Hassan, Manal M.

    2007-01-01

    To investigate the association between dietary exposure to food mutagens and risk of pancreatic cancer, we conducted a hospital-based case-control study at the University of Texas M. D. Anderson Cancer Center during June 2002 to May 2006. Atotal of 626 cases and 530 noncancer controls were frequency matched for race, sex and age (±5 years). Dietary exposure information was collected via personal interview using a meat preparation questionnaire. A significantly greater portion of the cases than controls showed a preference to well-done pork, bacon, grilled chicken, and pan-fried chicken, but not to hamburger and steak. Cases had a higher daily intake of food mutagens and mutagenicity activity (revertants per gram of daily meat intake) than controls did. The daily intakes of 2-amino-3,4,8-trimethylimidazo[4,5—f]quinoxaline (DiMeIQx) and benzo(a)pyrene (BaP), as well as the mutagenic activity, were significant predictors for pancreatic cancer (P = 0.008, 0.031, and 0.029, respectively) with adjustment of other confounders. A significant trend of elevated cancer risk with increasing DiMeIQx intake was observed in quintile analysis (Ptrend= 0.024). Ahigher intake of dietary mutagens (those in the two top quintiles) was associated with a 2-fold increased risk of pancreatic cancer among those without a family history of cancer but not among those with a family history of cancer. Apossible synergistic effect of dietary mutagen exposure and smoking was observed among individuals with the highest level of exposure (top 10%) to PhIP and BaP, Pinteraction= 0.09 and 0.099, respectively. These data support the hypothesis that dietary mutagen exposure alone and in interaction with other factors contribute to the development of pancreatic cancer. PMID:17416754

  3. Dietary exposure to lead of adults in Shenzhen city, China.

    PubMed

    Pan, Liubo; Wang, Zhou; Peng, Zhaoqiong; Liu, Guihua; Zhang, Huimin; Zhang, Jinzhou; Jiang, Jie; Pathiraja, Nimal; Xiao, Ying; Jiao, Rui; Huang, Wei

    2016-07-01

    Lead, a ubiquitous heavy metal, can be found in the environment and food. The present study is the first to estimate the lead dietary exposure of Shenzhen adults (≥ 20 years old) in various age-gender subgroups, and to assess the associated health risk. Food samples that represented the Shenzhen people's dietary pattern were collected and prepared for analysis. Lead was determined in 13 food groups using 276 individual cooked samples by inductively coupled plasma-mass spectrometry (ICP-MS). Dietary exposures were estimated by combining the analytical results with the local food consumption data of Shenzhen adults. The mean and 95th percentile lead exposure of Shenzhen adults were 0.59-0.73 and 0.75-0.94 μg kg(-1) bw day(-1), respectively. In all food groups, the highest lead exposure was from 'Eggs and their products' (42.4-51.6% of the total exposure); preserved eggs being the main contributor. The other major contributors to lead exposure of Shenzhen adults were 'Fish and seafood, and their products' (14.3-16.7% of the total exposure) and 'Vegetables and their products' (15.5-16.2% of the total exposure). The margin of exposure (MOE) approach was used for the risk assessment of lead, and the results showed that the risk was considered to be low in all age-gender groups for Shenzhen adults. However, having considered a number of toxic effects of lead, it is suggested that more efforts should be made to reduce the lead levels in foodstuff for Shenzhen adults.

  4. In Vivo Nanodetoxication for Acute Uranium Exposure.

    PubMed

    Guzmán, Luis; Durán-Lara, Esteban F; Donoso, Wendy; Nachtigall, Fabiane M; Santos, Leonardo S

    2015-06-15

    Accidental exposure to uranium is a matter of concern, as U(VI) is nephrotoxic in both human and animal models, and its toxicity is associated to chemical toxicity instead of radioactivity. We synthesized different PAMAM G4 and G5 derivatives in order to prove their interaction with uranium and their effect on the viability of red blood cells in vitro. Furthermore, we prove the effectiveness of the selected dendrimers in an animal model of acute uranium intoxication. The dendrimer PAMAM G4-Lys-Fmoc-Cbz demonstrated the ability to chelate the uranyl ion in vivo, improving the biochemical and histopathologic features caused by acute intoxication with uranium.

  5. Acute myelocytic leukemia after exposure to asbestos

    SciTech Connect

    Kishimoto, T.; Ono, T.; Okada, K.

    1988-08-15

    While the carcinogenicity of asbestos has been established in malignant mesotheliomas and lung cancers, and has recently been suspected in several other types of cancer, asbestos has not been implicated in the pathogenesis of acute leukemias. This article includes two cases of acute myelocytic leukemia in individuals with a long history of exposure to asbestos. Significant numbers of asbestos bodies were detected in specimens of their lungs and bone marrow. In addition, the kind of asbestos in both organs was crocidolite, which is implicated in carcinogenesis. No asbestos bodies were detected in the bone marrow specimens from a control group consisting of ten patients with lung cancer with similar occupational histories. The role of asbestos exposure in the development of leukemia requires further study.

  6. Dietary exposure to copper in the European Union and its assessment for EU regulatory risk assessment.

    PubMed

    Sadhra, Steven S; Wheatley, Andrew D; Cross, Hilary J

    2007-03-15

    EU legislation requires a multimedia exposure assessment for substances supplied within the EU. Dietary intake is the main source of exposure for the majority of the population hence an essential component of the human risk assessment. This paper describes the available data for dietary copper and its use in estimating daily intake including variability and determinants of exposure. Typical and reasonable worst-case estimates are derived for the general population from the available peer reviewed literature. Intakes from drinking water are found to exhibit more variability than those from food. Therefore, different exposure scenarios are derived to reflect the range of acute and chronic exposures that may occur. Estimates of typical copper intakes for the EU population are in the range 0.8-1.8 mg/day. Typical copper intakes of men are higher than those of women while the intake among the general adult population is higher than that of the elderly. Intakes of both men and women are generally close to the WHO normative requirements but may be somewhat lower in specific locations where background levels of copper are unusually low. Alcoholic beverages represent minor contribution daily copper intakes. Intakes for children are rather variable ranging broadly from 0.7 to 1.5 mg/day and are somewhat age and sex dependent. Greater uncertainty applies to the assessment of local exposure incorporating food produced on land directly impacted by contemporary copper industry emissions. Specifically, the extent to which soil is enriched in copper in these conditions is unclear. However, effective homeostatic control mechanisms in plants limit uptake and transfer to the human food chain. A best estimate of 0.25 mg/day in addition to regional exposure was derived. Drinking water is estimated to contribute only marginally to total copper intake in most cases. Higher intakes may occur in areas of poor water quality and/or corroded distribution systems. Such elevated exposures

  7. Assessment of human dietary exposure to arsenic through rice.

    PubMed

    Davis, Matthew A; Signes-Pastor, Antonio J; Argos, Maria; Slaughter, Francis; Pendergrast, Claire; Punshon, Tracy; Gossai, Anala; Ahsan, Habibul; Karagas, Margaret R

    2017-05-15

    Rice accumulates 10-fold higher inorganic arsenic (i-As), an established human carcinogen, than other grains. This review summarizes epidemiologic studies that examined the association between rice consumption and biomarkers of arsenic exposure. After reviewing the literature we identified 20 studies, among them included 18 observational and 2 human experimental studies that reported on associations between rice consumption and an arsenic biomarker. Among individuals not exposed to contaminated water, rice is a source of i-As exposure - rice consumption has been consistently related to arsenic biomarkers, and the relationship has been clearly demonstrated in experimental studies. Early-life i-As exposure is of particular concern due to its association with lifelong adverse health outcomes. Maternal rice consumption during pregnancy also has been associated with infant toenail total arsenic concentrations indicating that dietary exposure during pregnancy results in fetal exposure. Thus, the collective evidence indicates that rice is an independent source of arsenic exposure in populations around the world and highlights the importance of investigating its affect on health.

  8. Associations of dietary indices with biomarkers of dietary exposure and cardiovascular status among adolescents in Germany

    PubMed Central

    2012-01-01

    Background Adolescence is an important life stage for the development of dietary preferences and health behaviour. Longitudinal studies indicated that cardiovascular status in adolescence predicts cardiovascular risk marker values in adulthood. Several diet quality indices for adolescents have been developed in the past, but literature concerning associations between indices and biomarkers of dietary exposure and cardiovascular status is rather sparse. Hence, the aim of this study was to analyse associations of dietary indices with biomarkers of dietary exposure and cardiovascular status. Methods For the present analysis, data from the German Health Interview and Examination Survey for Children and Adolescents (KiGGS 2003–2006) were used. The analysis included 5,198 adolescents, aged 12 to 17 years. The Healthy Food Diversity Index (HFD), the Healthy Nutrition Score for Kids and Youth (HuSKY), the Indicator Food Index (IFI) and a simple fruit/vegetable intake index were derived from food frequency questionnaire information to indicate a healthy diet. Adjusted mean values for homocysteine, uric acid, CRP, total cholesterol, HDL-C, ferritin, HbA1c, folate, vitamin B12 and BMI were calculated using complex-samples general linear models for quintiles of the different indices. Furthermore, the agreement in ranking between the different indices was calculated by weighted kappa. All statistical analyses were conducted for boys and girls separately, and were adjusted for potential confounders. Results Folate was positively associated with the HFD, the HuSKY, and fruit/vegetable intake for both boys and girls and with IFI for boys. Among girls, positive associations were seen between vitamin B12 and the IFI and between diastolic blood pressure and the IFI as well as fruit/vegetable intake. A negative association was found between homocysteine and the HFD, the HuSKY, and the IFI for both boys and girls and with fruit/vegetable intake for boys. Among boys, uric acid and

  9. TESTING DUPLICATE DIET SAMPLE COLLECTION METHODS FOR MEASURING PERSONAL DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    Dietary ingestion may be a significant pathway of human exposure to many potentially toxic chemicals. The U.S.Environmental Protection Agency-National Human Exposure Laboratory has made the development of methods for measuring persoanl dietary exposures a high priority for its di...

  10. TESTING DUPLICATE DIET SAMPLE COLLECTION METHODS FOR MEASURING PERSONAL DIETARY EXPOSURES TO CHEMICAL CONTAMINANTS

    EPA Science Inventory

    Dietary ingestion may be a significant pathway of human exposure to many potentially toxic chemicals. The U.S.Environmental Protection Agency-National Human Exposure Laboratory has made the development of methods for measuring persoanl dietary exposures a high priority for its di...

  11. Acute Selenium Toxicity Associated With a Dietary Supplement

    PubMed Central

    MacFarquhar, Jennifer K.; Broussard, Danielle L.; Melstrom, Paul; Hutchinson, Richard; Wolkin, Amy; Martin, Colleen; Burk, Raymond F.; Dunn, John R.; Green, Alice L.; Hammond, Roberta; Schaffner, William; Jones, Timothy F.

    2011-01-01

    Background Selenium is an element necessary for normal cellular function, but it can have toxic effects at high doses. We investigated an outbreak of acute selenium poisoning. Methods A case was defined as the onset of symptoms of selenium toxicity in a person within 2 weeks after ingesting a dietary supplement manufactured by “Company A,” purchased after January 1, 2008. We conducted case finding, administered initial and 90-day follow-up questionnaires to affected persons, and obtained laboratory data where available. Results The source of the outbreak was identified as a liquid dietary supplement that contained 200 times the labeled concentration of selenium. Of 201 cases identified in 10 states, 1 person was hospitalized. The median estimated dose of selenium consumed was 41 749 μg/d (recommended dietary allowance is 55 μg/d). Frequently reported symptoms included diarrhea (78%), fatigue (75%), hair loss (72%), joint pain (70%), nail discoloration or brittleness (61%), and nausea (58%). Symptoms persisting 90 days or longer included fingernail discoloration and loss (52%), fatigue (35%), and hair loss (29%). The mean initial serum selenium concentration of 8 patients was 751 μg/L (reference range, ≤125 μg/L). The mean initial urine selenium concentration of 7 patients was 166 μg/24 h (reference range, ≤55 μg/24 h). Conclusions Toxic concentrations of selenium in a liquid dietary supplement resulted in a widespread outbreak. Had the manufacturers been held to standards used in the pharmaceutical industry, it may have been prevented. PMID:20142570

  12. The food metabolome: a window over dietary exposure.

    PubMed

    Scalbert, Augustin; Brennan, Lorraine; Manach, Claudine; Andres-Lacueva, Cristina; Dragsted, Lars O; Draper, John; Rappaport, Stephen M; van der Hooft, Justin J J; Wishart, David S

    2014-06-01

    The food metabolome is defined as the part of the human metabolome directly derived from the digestion and biotransformation of foods and their constituents. With >25,000 compounds known in various foods, the food metabolome is extremely complex, with a composition varying widely according to the diet. By its very nature it represents a considerable and still largely unexploited source of novel dietary biomarkers that could be used to measure dietary exposures with a high level of detail and precision. Most dietary biomarkers currently have been identified on the basis of our knowledge of food compositions by using hypothesis-driven approaches. However, the rapid development of metabolomics resulting from the development of highly sensitive modern analytic instruments, the availability of metabolite databases, and progress in (bio)informatics has made agnostic approaches more attractive as shown by the recent identification of novel biomarkers of intakes for fruit, vegetables, beverages, meats, or complex diets. Moreover, examples also show how the scrutiny of the food metabolome can lead to the discovery of bioactive molecules and dietary factors associated with diseases. However, researchers still face hurdles, which slow progress and need to be resolved to bring this emerging field of research to maturity. These limits were discussed during the First International Workshop on the Food Metabolome held in Glasgow. Key recommendations made during the workshop included more coordination of efforts; development of new databases, software tools, and chemical libraries for the food metabolome; and shared repositories of metabolomic data. Once achieved, major progress can be expected toward a better understanding of the complex interactions between diet and human health. © 2014 American Society for Nutrition.

  13. Effects of aqueous, dietary and combined exposures of cadmium to Ceriodaphnia dubia.

    PubMed

    Sofyan, Agus; Price, David J; Birge, Wesley J

    2007-10-15

    While effects of water-borne metal exposures on freshwater animals have been well documented, the effect of dietary metal exposure is less understood but is gaining importance. However, little attention has been given to the importance of combining both exposure pathways. In this study, we compared effects of aqueous ('water only'), dietary ('food only') and combined ('water+food') exposures of cadmium to the freshwater cladocerans, Ceriodaphnia dubia. Major test endpoints included survival, feeding rate and reproduction. The C. dubia three-brood reproduction tests were conducted according to the United States Environmental Protection Agency (U.S. EPA) methods. Three exposure scenarios were used: aqueous, dietary, and combined aqueous and dietary exposures. Results showed that all three exposures affected survival, feeding rate and reproduction of C. dubia. Interestingly, combined exposure showed contribution effects of aqueous and dietary exposures. Lower cadmium concentrations were needed in combined exposure to produce effects as compared to higher concentrations in aqueous or dietary exposure alone. These results demonstrated the potential importance of dietary and combined exposures for consideration of cadmium regulation and risk assessment of metals.

  14. Acute methamphetamine exposure inhibits cardiac contractile function.

    PubMed

    Turdi, Subat; Schamber, Robbie M; Roe, Nathan D; Chew, Herbert G; Culver, Bruce; Ren, Jun

    2009-09-10

    Methamphetamine, a commonly seen substance of abuse, has been reported to exert detrimental effect on bodily function including the cardiovascular system although its mechanism of action is poorly understood. This study was designed to examine the direct impact of methamphetamine on isolated whole heart and single cardiomyocyte contractile function. Murine hearts and isolated cardiomyocytes from adult FVB mice were exposed to various concentrations of methamphetamine for 30min prior to the assessment of mechanical function using a Langendroff apparatus and an IonOptix Myocam system, respectively. Cardiac contractile properties analyzed included maximal velocity of left ventricular pressure development and decline (+/-dP/dt), peak shortening amplitude (PS), maximal velocity of shortening/relengthening (+/-dLdt), time-to-PS (TPS), time-to-90% relengthening (TR(90)), resting and electrically stimulated increase of intracellular Ca(2+) as well as intracellular Ca(2+) decay. Our results revealed that acute methamphetamine exposure depressed +/-dP/dt, PS and rise of intracellular Ca(2+) without affecting +/-dLdt, TPS, TR(90), resting intracellular Ca(2+) and intracellular Ca(2+) decay. Furthermore, methamphetamine nullified the adrenergic agonist norepinephrine-elicited positive cardiomyocyte contractile response, including elevated PS, +/-dLdt and shortened TR(90) without affecting TPS. Western blot analysis showed unchanged expression of sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) and phospholamban, associated with upregulated Na(+)-Ca(2+) exchanger levels following acute methamphetamine exposure. In addition, methamphetamine promoted overt cardiomyocyte protein damage evaluated by carbonyl formation. Taken together, these results demonstrate direct cardiac depressant effect of methamphetamine in myocardium and isolated cardiomyocytes, possibly associated with protein damage and dampened adrenergic response.

  15. Acute Methamphetamine Exposure Inhibits Cardiac Contractile Function

    PubMed Central

    Turdi, Subat; Schamber, Robbie M.; Roe, Nathan D.; Chew, Herbert G.; Culver, Bruce; Ren, Jun

    2009-01-01

    Methamphetamine, a commonly seen substance of abuse, has been reported to exert detrimental effect on bodily function including the cardiovascular system although its mechanism of action is poorly understood. This study was designed to examine the direct impact of methamphetamine on isolated whole heart and single cardiomyocyte contractile function. Murine hearts and isolated cardiomyocytes from adult FVB mice were exposed to various concentrations of methamphetamine for 30 min prior to the assessment of mechanical function using a Langendroff apparatus and an IonOptix Myocam® system, respectively. Cardiac contractile properties analyzed included maximal velocity of left ventricular pressure development and decline (± dP/dt), peak shortening amplitude (PS), maximal velocity of shortening/relengthening (± dLdt), time-to-PS (TPS), time-to-90% relengthening (TR90), resting and electrically-stimulated increase of intracellular Ca2+ as well as intracellular Ca2+ decay. Our results revealed that acute methamphetamine exposure depressed ± dP/dt, PS and rise of intracellular Ca2+ without affecting ± dLdt, TPS, TR90, resting intracellular Ca2+ and intracellular Ca2+ decay. Furthermore, methamphetamine nullified the adrenergic agonist norepinephrine-elicited positive cardiomyocyte contractile response, including elevated PS, ± dLdt and shortened TR90 without affecting TPS. Western blot analysis showed unchanged expression of sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2a) and phospholamban, associated with upregulated Na+-Ca2+ exchanger levels following acute methamphetamine exposure. In addition, methamphetamine promoted overt cardiomyocyte protein damage evaluated by carbonyl formation. Taken together, these results demonstrate direct cardiac depressant effect of methamphetamine in myocardium and isolated cardiomyocytes, possibly associated with protein damage and dampened adrenergic response. PMID:19481142

  16. THE THREE INTERACTING FACTORS ASSOCIATED WITH CHILDREN'S DIETARY EXPOSURES: ENVIRONMENTAL CONCENTRATIONS, FOOD CONTAMINATION, AND CHILDREN'S BEHAVIORS

    EPA Science Inventory

    The dietary contribution to an aggregate exposure assessment is potentially an important pathway of exposure especially for young children. Enviornmental contamination appearing in the child's diet can result from contamination in the food as purchased or due to preparing, servin...

  17. Cumulative dietary exposure of the population of Denmark to pesticides.

    PubMed

    Jensen, Bodil Hamborg; Petersen, Annette; Nielsen, Elsa; Christensen, Tue; Poulsen, Mette Erecius; Andersen, Jens Hinge

    2015-09-01

    We used the Hazard Index (HI) method to carry out a cumulative risk assessment after chronic dietary exposure to all monitored pesticides in fruit, vegetables and cereals for various consumer groups in Denmark. Residue data for all the pesticides were obtained from the Danish monitoring programme during the period 2004-2011. Food consumption data were obtained from DANSDA (the DAnish National Survey of Diet and physical Activity) for the period 2005-2008. The calculations were made using three different models to cope with residues below the limit of reporting (LOR). We concluded that a model that included processing factors and set non-detects to ½ LOR, but limited the correction (Model 3), gave the most realistic exposure estimate. With Model 3 the HI was calculated to be 0.44 for children and 0.18 for adults, indicating that there is no risk of adverse health effects following chronic cumulative exposure to the pesticides found in fruit, vegetables and cereals on the Danish market. The HI was below 1 even for consumers who eat more than 550 g of fruit and vegetables per day, corresponding to 1/3 of the population. Choosing Danish-produced commodities whenever possible could reduce the HI by a factor of 2. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Simulating cholinesterase inhibition in birds caused by dietary insecticide exposure

    USGS Publications Warehouse

    Corson, M.S.; Mora, M.A.; Grant, W.E.

    1998-01-01

    We describe a stochastic simulation model that simulates avian foraging in an agricultural landscape to evaluate factors affecting dietary insecticide exposure and to predict post-exposure cholinesterase (ChE) inhibition. To evaluate the model, we simulated published field studies and found that model predictions of insecticide decay and ChE inhibition reasonably approximated most observed results. Sensitivity analysis suggested that foraging location usually influenced ChE inhibition more than diet preferences or daily intake rate. Although organophosphorus insecticides usually caused greater inhibition than carbamate insecticides, insecticide toxicity appeared only moderately important. When we simulated impact of heavy insecticide applications during breeding seasons of 15 wild bird species, mean maximum ChE inhibition in most species exceeded 20% at some point. At this level of inhibition, birds may experience nausea and/or may exhibit minor behavioral changes. Simulated risk peaked in April-May and August-September and was lowest in July. ChE inhibition increased with proportion of vegetation in the diet. This model, and ones like it, may help predict insecticide exposure of and sublethal ChE inhibition in grassland animals, thereby reducing dependence of ecological risk assessments on field studies alone.

  19. DIETARY EXPOSURES OF YOUNG CHILDREN, PART 1: MODEL DEVELOPMENT AND STUDY DESIGN

    EPA Science Inventory

    Young children contact surfaces (hands, floors, etc.) that may be contaminated with pesticides. Thus, dietary exposures of young children are difficult to measure, but are needed to support the aggregate exposure assessments. Evaluation of dietary field protocols and a total die...

  20. Probabilistic Modeling of Dietary Arsenic Exposure and Dose and Evaluation with 2003-2004 NHANES Data

    EPA Science Inventory

    Dietary exposure from food to toxic inorganic arsenic (iAs) in the general U.S. population has not been well studied. The goal of this research was to quantify dietary arsenic As exposure and analyze the major contributors to total As (tAs) and iAs. Another objective was to com...

  1. Probabilistic Modeling of Dietary Arsenic Exposure and Dose and Evaluation with 2003-2004 NHANES Data

    EPA Science Inventory

    Dietary exposure from food to toxic inorganic arsenic (iAs) in the general U.S. population has not been well studied. The goal of this research was to quantify dietary arsenic As exposure and analyze the major contributors to total As (tAs) and iAs. Another objective was to com...

  2. Dietary restraint moderates the effects of food exposure on women's body and weight satisfaction.

    PubMed

    Geschwind, Nicole; Roefs, Anne; Lattimore, Paul; Fett, Anne-Kathrin; Jansen, Anita

    2008-11-01

    The influence of dietary restraint and food exposure on body satisfaction was tested. Body and weight satisfaction were measured before and after exposure to either high- or low-caloric food, without actual eating. Independent of caloric condition, higher dietary restraint was associated with a decrease in body satisfaction after food exposure. With regard to weight satisfaction, however, the association between higher dietary restraint and decreased weight satisfaction was specific for the high-caloric condition. Thus, the actual eating of food is not necessary for decreased body and weight satisfaction to occur, suggesting an exposure-induced activation of dysfunctional cognitions in restrained eaters.

  3. Dietary exposure of 18-month-old Guadeloupian toddlers to chlordecone.

    PubMed

    Seurin, Sophie; Rouget, Florence; Reninger, Jean-Cédric; Gillot, Nadège; Loynet, Claire; Cordier, Sylvaine; Multigner, Luc; Leblanc, Jean-Charles; Volatier, Jean-Luc; Héraud, Fanny

    2012-08-01

    Chlordecone is an organochlorine insecticide used in the French West Indies until 1993. Toddlers are expected to be differently exposed than older children and adults. The dietary exposure to chlordecone of 18-month-old Guadeloupian toddlers was assessed through different scenarios depending on whether the subjects live on a soil-contaminated place or not and on their supply habits. Food contamination data came from the RESO study performed in 2005-2006. Consumption data derived from a dietary survey conducted in 2005-2008. Results were compared to those of other age groups. Chronic dietary exposures to chlordecone were estimated in a range of 0.018-0.051 μg/kg bw/day (P95: 0.044-0.096) for toddlers living in a non contaminated area and between 0.045-0.078 μg/kg bw/day (P95: 0.110-0.144) for toddlers living in a contaminated area. The probability of exceeding the chronic health-based value of 0.5 μg/kg bw/day was null. These results suggest that 18-month-old toddlers are less exposed than groups aged over 3 years old. This can be explained by their consumption pattern mostly based on milk and fruits, which are not highly contaminated by chlordecone. The acute health-based value of 10 μg/kg bw/day could be exceeded when consuming of highly contaminated taros, showing the importance of regulatory maximum limit. Copyright © 2012 Elsevier Inc. All rights reserved.

  4. Cumulative dietary exposure to a selected group of pesticides of the triazole group in different European countries according to the EFSA guidance on probabilistic modelling.

    PubMed

    Boon, Polly E; van Donkersgoed, Gerda; Christodoulou, Despo; Crépet, Amélie; D'Addezio, Laura; Desvignes, Virginie; Ericsson, Bengt-Göran; Galimberti, Francesco; Ioannou-Kakouri, Eleni; Jensen, Bodil Hamborg; Rehurkova, Irena; Rety, Josselin; Ruprich, Jiri; Sand, Salomon; Stephenson, Claire; Strömberg, Anita; Turrini, Aida; van der Voet, Hilko; Ziegler, Popi; Hamey, Paul; van Klaveren, Jacob D

    2015-05-01

    The practicality was examined of performing a cumulative dietary exposure assessment according to the requirements of the EFSA guidance on probabilistic modelling. For this the acute and chronic cumulative exposure to triazole pesticides was estimated using national food consumption and monitoring data of eight European countries. Both the acute and chronic cumulative dietary exposures were calculated according to two model runs (optimistic and pessimistic) as recommended in the EFSA guidance. The exposures obtained with these model runs differed substantially for all countries, with the highest exposures obtained with the pessimistic model run. In this model run, animal commodities including cattle milk and different meat types, entered in the exposure calculations at the level of the maximum residue limit (MRL), contributed most to the exposure. We conclude that application of the optimistic model run on a routine basis for cumulative assessments is feasible. The pessimistic model run is laborious and the exposure results could be too far from reality. More experience with this approach is needed to stimulate the discussion of the feasibility of all the requirements, especially the inclusion of MRLs of animal commodities which seem to result in unrealistic conclusions regarding their contribution to the dietary exposure.

  5. Polybrominated diphenyl ethers: occurrence, dietary exposure, and toxicology.

    PubMed Central

    Darnerud, P O; Eriksen, G S; Jóhannesson, T; Larsen, P B; Viluksela, M

    2001-01-01

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in plastics (concentration, 5--30%) and in textile coatings. Commercial products consist predominantly of penta-, octa-, and decabromodiphenyl ether mixtures, and global PBDE production is about 40,000 tons per year. PBDEs are bioaccumulated and biomagnified in the environment, and comparatively high levels are often found in aquatic biotopes from different parts of the world. During the mid-1970--1980s there was a substantial increase in the PBDE levels with time in both sediments and aquatic biota, whereas the latest Swedish data (pike and guillemot egg) may indicate that levels are at steady state or are decreasing. However, exponentially increasing PBDE levels have been observed in mother's milk during 1972--1997. Based on levels in food from 1999, the dietary intake of PBDE in Sweden has been estimated to be 0.05 microg per day. Characteristic end points of animal toxicity are hepatotoxicity, embryotoxicity, and thyroid effects as well as maternal toxicity during gestation. Recently, behavioral effects have been observed in mice on administration of PBDEs during a critical period after birth. Based on the critical effects reported in available studies, we consider the lowest-observed-adverse-effect level (LOAEL) value of the PBDE group to be 1 mg/kg/day (primarily based on effects of pentaBDEs). In conclusion, with the scientific knowledge of today and based on Nordic intake data, the possible consumer health risk from PBDEs appears limited, as a factor of over 10(6) separates the estimated present mean dietary intake from the suggested LOAEL value. However, the presence of many and important data gaps, including those in carcinogenicity, reproduction, and developmental toxicity, as well as additional routes of exposure, make this conclusion only preliminary. Moreover, the time trend of PBDEs in human breast milk is alarming for the future. PMID:11250805

  6. [Exposure assessment of liver cancer attributed to dietary aflatoxins exposure in Chinese residents].

    PubMed

    Wang, Jun; Liu, Xiu-Mei; Zhang, Zhi-Qiang

    2009-06-01

    To evaluate the risk of liver cancer attributed to dietary aflatoxins exposure in Chinese residents. Mathematics model and "Margin of Exposure (MOE)" methods were employed in this study. The data used in mathematics model came from Joint FAO/WHO Expert Committee on Food Additives (JECFA) and the detection results of hepatitis B virus ( HBV) indicator in Chinese residents' blood sample in 2004. The data used in MOE model came from animal experiments, the fourth nutrition and health investigation among Chinese residents, and national inspection network for food contaminations. Mathematics model indicated that for those people who were exposed to aflatoxins at average level (665.43 ng/d), the liver cancer incidence rate resulting from aflatoxins exposure was 0.4033 per 100 thousand person years. For those people who were exposed to aflatoxins at a high level (97.5 percentile, 24 787.20 ng/d) the liver cancer incidence rate attributed to aflatoxins exposure was 15.0215 per 100 thousand person years. Results from the MOE method showed that for the people in whole country, urban and rural areas who were exposed to aflatoxins at average level (0.011 09, 0.008 13 and 0.012 49 microg x kg(-1) x d(-1) respectively), the MOE values for aflatoxins to cause liver cancer were 9017.1, 12 304.7 and 8006.4 respectively. For those people who were exposed to aflatoxins at a high level (97.5 percentile, 0.413 10, 0.289 30 and 0.489 50 microg x kg(-1) x d(-1) respectively), the MOE values for aflatoxins to cause liver cancer were 242.1, 345.7 and 204.3 for whole country, urban and rural areas, respectively. For the people whose dietary aflatoxins exposure at average level, the risk of liver cancer attributed to aflatoxins is middle. For the people whose dietary aflatoxins exposure at high level, this kind of risk should be high.

  7. Acute radiodermatitis from occupational exposure to iridium 192

    SciTech Connect

    Becker, J.; Rosen, T. )

    1989-12-01

    Industrial radiography using the man-made radioisotope iridium 192 is commonplace in the southern states. Despite established procedures and safeguards, accidental exposure may result in typical acute radiodermatitis. We have presented a clinical example of this phenomenon.9 references.

  8. Are Dietary Restraint Scales Valid Measures of Acute Dietary Restriction? Unobtrusive Observational Data Suggest Not

    ERIC Educational Resources Information Center

    Stice, Eric; Fisher, Melissa; Lowe, Michael R.

    2004-01-01

    The finding that dietary restraint scales predict onset of bulimic pathology has been interpreted as suggesting that dieting causes this eating disturbance, despite the dearth of evidence that these scales are valid measures of dietary restriction. The authors conducted 4 studies that tested whether dietary restraint scales were inversely…

  9. Are Dietary Restraint Scales Valid Measures of Acute Dietary Restriction? Unobtrusive Observational Data Suggest Not

    ERIC Educational Resources Information Center

    Stice, Eric; Fisher, Melissa; Lowe, Michael R.

    2004-01-01

    The finding that dietary restraint scales predict onset of bulimic pathology has been interpreted as suggesting that dieting causes this eating disturbance, despite the dearth of evidence that these scales are valid measures of dietary restriction. The authors conducted 4 studies that tested whether dietary restraint scales were inversely…

  10. Prioritization of pesticides based on daily dietary exposure potential as determined from the SHEDS model

    EPA Science Inventory

    A major pathway for exposure to many pesticides is through diet. The objectives were to rank pesticides by comparing their calculated daily dietary exposure as determined by EPA's Stochastic Human Exposure and Dose Simulation (SHEDS) to single pesticides for different age groups ...

  11. Prioritization of pesticides based on daily dietary exposure potential as determined from the SHEDS model

    EPA Science Inventory

    A major pathway for exposure to many pesticides is through diet. The objectives were to rank pesticides by comparing their calculated daily dietary exposure as determined by EPA's Stochastic Human Exposure and Dose Simulation (SHEDS) to single pesticides for different age groups ...

  12. Toxicity and immune system effects of dietary deltamethrin exposure in tiger salamanders (Ambystoma tigrinum).

    PubMed

    Froese, Jennifer M W; Smits, Judit E G; Forsyth, Douglas J; Wickstrom, Mark L

    2009-01-01

    One theory proposed to explain the global declines in amphibian populations involves contaminant-induced immune alteration and subsequent increased susceptibility to infectious disease. The goal of this study was twofold, to (1) study acute oral toxicity of deltamethrin (cyclopropanecarboxylic acid, 3-(2,2-dibromoethenyl)-2,2-dimethyl cyano(3-phenoxyphenyl)methyl ester) in tiger salamanders (Ambystoma tigrinum), and (2) evaluate whether the insecticide deltamethrin produces immunosuppression in these animals. In the acute toxicity study, tiger salamanders receiving single doses of deltamethrin ranging from 1 to 35 mg/kg displayed intention tremors, hypersalivation, ataxia, choreoathetosis (writhing), severe depression (immobility with minimal response to stimuli), and death. For acute effects, based on clinical signs, the median lethal dose (LD(50)) and lowest observed adverse effect level (LOAEL) were estimated to be 5 to 10 mg/kg and 1 mg/kg, respectively. The LOAEL in animals dosed 3 times per week for 4 wk was 400 microg/kg/d. The endpoints for the immunotoxicity study included lymphoid organ mass and histopathology, hematological variables, and functional assays of phagocytosis, oxidative burst, and lymphoblastic transformation. Tiger salamanders in 4 treatment groups (0, 4, 40, or 400 microg/kg/d) were dosed with deltamethrin via the diet 3 times per week for 4 wk. Deltamethrin exposure resulted in increased liver mass, packed cell volume, and total plasma protein concentration, but these effects were not dose dependent. The relative mass of kidney and spleen, plasma albumin and globulin concentrations, and circulating leukocyte numbers were not affected by deltamethrin exposure, nor were phagocytosis, oxidative burst, and lymphoblastic transformation. This study shows that at moderate levels of exposure, deltamethrin may be neurotoxic to tiger salamanders. However, based on the immune assays considered in this study there was no evidence of immunosuppression

  13. Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures.

    PubMed

    Lorber, Matthew; Schecter, Arnold; Paepke, Olaf; Shropshire, William; Christensen, Krista; Birnbaum, Linda

    2015-04-01

    Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a "canned fraction" parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and

  14. Exposure assessment of adult intake of bisphenol A (BPA) with emphasis on canned food dietary exposures

    PubMed Central

    Lorber, Matthew; Schecter, Arnold; Paepke, Olaf; Shropshire, William; Christensen, Krista; Birnbaum, Linda

    2015-01-01

    Bisphenol A (BPA) is a high-volume, synthetic compound found in epoxy resins and plastics used in food packaging. Food is believed to be a major source of BPA intake. In this study, we measured the concentration of BPA in convenience samplings of foodstuffs purchased in Dallas, Texas. Sampling entailed collection of 204 samples of fresh, frozen, and canned foods in two rounds in 2010. BPA was positive in 73% of the canned food samples, while it was found in only 7% of non-canned foods at low concentrations. The results of this food sampling program were used to calculate adult dietary intakes of BPA. A pathway approach combined food intakes, a “canned fraction” parameter which described what portion of total intake of that food came from canned products, and measured food concentrations. Dietary intakes were calculated as 12.6 ng/kg-day, of which 12.4 ng/kg-day was from canned foods. Canned vegetable intakes alone were 11.9 ng/kg-day. This dietary intake was compared to total intakes of BPA estimated from urine measurements of the National Health and Nutrition Examination Survey (NHANES). Total adult central tendency intakes ranged from 30 to 70 ng/kg-day for NHANES cycles between 2005 and 2010. Three possibilities were explored to explain the difference between these two approaches for intake estimation. Not all foods which may have been canned, particularly canned beverages such as soft drinks, were sampled in our food sampling program. Second, non-food pathways of exposure may be important for adults, including thermal paper exposures, and dust and air exposures. Finally, our canned food concentrations may not be adequately representative of canned foods in the United States; they were found to be generally lower compared to canned food concentrations measured in six other worldwide food surveys including three in North America. Our finding that canned food concentrations greatly exceeded non-canned concentrations was consistent with other studies, and

  15. Dietary intake and childhood leukemia: The Diet and Acute Lymphoblastic Leukemia Treatment (DALLT) cohort study.

    PubMed

    Ladas, Elena J; Orjuela, Manuela; Stevenson, Kristen; Cole, Peter D; Lin, Meiko; Athale, Uma H; Clavell, Luis A; Leclerc, Jean-Marie; Michon, Bruno; Schorin, Marshall A; Welch, Jennifer Greene; Asselin, Barbara L; Sallan, Stephen E; Silverman, Lewis B; Kelly, Kara M

    2016-10-01

    Children with acute lymphoblastic leukemia (ALL) are at elevated risk for nutrition-related morbidity both during and after therapy. We present the demographic characteristics and nutrient intake at study entry of a prospective cohort in which evaluating dietary intake in children diagnosed with ALL was investigated. Dietary intake data were collected for participants enrolled on the Dana-Farber Cancer Institute ALL Consortium Protocol. Dietary intake was assessed with a food frequency questionnaire and was compared with the dietary reference intake by ALL risk group (standard and high risk). Dietary intake data were collected from 81% of participants (n = 640). We found that 27% of participants were overweight/obese. Intake of total calories and other nutrients exceeded the dietary reference intake in up to 79% of children. This was evident in both risk groups and was pronounced among younger children. For micronutrients, dietary intake of calcium, vitamin D (females only), and zinc differed significantly between patients with standard-risk and those with high-risk ALL. This study was successful in collecting dietary intake data at the time of cancer diagnosis in a multicenter setting in a pediatric population at high-risk for nutrition-related morbidity. We identified "at-risk" dietary intakes, which vary by sex and ALL risk group; such patients may benefit from future dietary interventions. Copyright © 2016 Elsevier Inc. All rights reserved.

  16. Formaldehyde exposure and acute health effects study

    SciTech Connect

    Quackenboss, J.J.; Lebowitz, M.D.; Michaud, J.P.; Bronnimann, D. )

    1989-01-01

    To assess the effects of formaldehyde exposures on health, exposure groups were defined using baseline exposure and health questionnaires. Formaldehyde concentrations were poorly correlated with these exposure classifications, perhaps due to the time delay between classification and monitoring. The 151 households reported here had a mean HCHO concentration of 35 (S.E. 1.5 and median 30) {mu}g/m{sup 3}. Passive samplers prepared in our lab were calibrated in a chamber to derive an estimated sampling rate of 0.311 {mu}g/(mg {center dot} m{sup {minus}3} {center dot} hr). They were also compared to commercially available samplers inside of the homes, with a correlation coefficient of 0.896 and mean difference of 2.6 {mu}g/m{sup 3}. In this report of initial findings from an ongoing study, daily symptoms and peak expiratory flow measurements were compared with an HCHO exposure classification based on the median measured concentrations. None of the symptoms groups were related to HCHO exposure when controlling for age and sex. There was a significant relationship between HCHO exposure and variability in peak expiratory flows that was dependent on age group. It may be especially important to assess the variability in reactive individuals and children to determine the short-term effects of HCHO exposures and possible long-term consequences.

  17. Regulation of adenosine transport by acute and chronic ethanol exposure

    SciTech Connect

    Nagy, L.E.; Casso, D.; Diamond, I.; Gordon, A.S. )

    1989-02-09

    Chronic exposure to ethanol results in a desensitization of adenosine receptor-stimulated cAMP production. Since adenosine is released by cells and is known to desensitize its own as well as other receptors, it may be involved in ethanol-induced desensitization of adenosine receptor function. Therefore, we have examine the acute and chronic effects of ethanol on the transport of adenosine via the nucleoside transport. Acute exposure to ethanol caused an inhibition of adenosine uptake in S49 lymphoma cells. This decrease in uptake resulted in accumulation of extracellular adenosine after ethanol exposure. The effect of ethanol was specific to nucleoside transport. Uptake of uridine, also transported by the nucleoside transporter, was inhibited by ethanol to the same degree as adenosine uptake, while neither isoleucine nor deoxyglucose uptake was altered by ethanol treatment. Inhibition of adenosine uptake by ethanol was non-competitive and dependent on the concentration of ethanol. After chronic exposure to ethanol, cells became tolerant to the acute effects of ethanol. There was no longer an acute inhibition of adenosine uptake, nor was these accumulation of extracellular adenosine. Chronic ethanol exposure also resulted in a decrease in the absolute rate of adenosine uptake. Binding studies using a high affinity lignad for the nucleoside transporter, nitrobenzylthioinosine (NBMPR), indicate that this decreased uptake was due to a decrease in the maximal number of binding sites. These ethanol-induced changes in adenosine transport may be important for the acute and chronic effects of ethanol.

  18. Prioritization of pesticides based on daily dietary exposure potential as determined from the SHEDS model.

    PubMed

    Melnyk, Lisa Jo; Wang, Zhaohui; Li, Zhilin; Xue, Jianping

    2016-10-01

    A major pathway for exposure to many pesticides is through diet. The objectives were to rank pesticides by comparing their calculated daily dietary exposure as determined by EPA's Stochastic Human Exposure and Dose Simulation (SHEDS) to single pesticides for different age groups to acceptable daily intakes (ADI), characterize pesticide trends in exposures over different time periods, and determine commodities contributing to pesticide exposures. SHEDS was applied, using Pesticide Data Program (PDP) (1991-2011) and pesticide usage data on crops from USDA combined with NHANES dietary consumption data, to generate exposure estimates by age group. ADI data collected from EPA, WHO, and other sources were used to rank pesticides based on relativeness of the dietary exposure potential to ADI by age groups. Sensitivity analysis provided trends in pesticide exposures. Within SHEDS, commodities contributing the majority of pesticides with greatest exposure potential were determined. The results indicated that the highest ranking pesticides were methamidophos and diazinon which exceeded 100% of the ADI. Sensitivity analysis indicated that exposure to methamidophos, diazinon, malathion, ethion and formetanate hydrochloride had a marked decrease from 1991-1999 to 2000-2011. Contributions analysis indicated that apples, mushroom, carrots, and lettuce contributed to diazinon exposure. Beans and pepper contributed to methamidophos exposure. Published by Elsevier Ltd.

  19. A Dietary-Wide Association Study (DWAS) of Environmental Metal Exposure in US Children and Adults

    PubMed Central

    Davis, Matthew A.; Gilbert-Diamond, Diane; Karagas, Margaret R.; Li, Zhigang; Moore, Jason H.; Williams, Scott M.; Frost, H. Robert

    2014-01-01

    Background A growing body of evidence suggests that exposure to toxic metals occurs through diet but few studies have comprehensively examined dietary sources of exposure in US populations. Purpose Our goal was to perform a novel dietary-wide association study (DWAS) to identify specific dietary sources of lead, cadmium, mercury, and arsenic exposure in US children and adults. Methods We combined data from the National Health and Nutrition Examination Survey with data from the US Department of Agriculture's Food Intakes Converted to Retail Commodities Database to examine associations between 49 different foods and environmental metal exposure. Using blood and urinary biomarkers for lead, cadmium, mercury, and arsenic, we compared sources of dietary exposure among children to that of adults. Results Diet accounted for more of the variation in mercury and arsenic than lead and cadmium. For instance we estimate 4.5% of the variation of mercury among children and 10.5% among adults is explained by diet. We identified a previously unrecognized association between rice consumption and mercury in a US study population – adjusted for other dietary sources such as seafood, an increase of 10 g/day of rice consumption was associated with a 4.8% (95% CI: 3.6, 5.2) increase in blood mercury concentration. Associations between diet and metal exposure were similar among children and adults, and we recapitulated other known dietary sources of exposure. Conclusion Utilizing this combination of data sources, this approach has the potential to identify and monitor dietary sources of metal exposure in the US population. PMID:25198543

  20. Effects of chronic dietary copper exposure on growth and reproduction of Daphnia magna.

    PubMed

    De Schamphelaere, Karel A C; Janssen, Colin R

    2004-08-01

    A matter of current, intense debate with regard to the effects of metals on biological systems is the potential toxicity of metals associated with food particles. Recently developed biotic ligand models (BLM), which predict the toxicity of waterborne metals, may not be valid if the dietary exposure route contributes to metal toxicity. The present study is, to our knowledge, the first that investigates the potential toxicity of dietary copper to a freshwater invertebrate (i.e., Daphnia magna) feeding on a live diet (i.e., the green alga Pseudokircheneriella subcapitata). Algae were exposed for 3 d to different copper concentrations, resulting in algal copper burdens between approximately 6.2 X 10(-16) and 250 x 10(-16) g cell(-1). These algae were then used as food in chronic, 21-d D. magna toxicity tests in which growth, reproduction, and copper accumulation were assessed. Three exposure scenarios were tested: A waterborne exposure, a dietary exposure, and a combined waterborne and dietary exposure. Although exposure to dietary copper resulted in an increased copper body burden of the adult daphnids, it did not contribute to toxicity and did not affect the 21-d effect concentrations expressed as waterborne copper, indicating that the previously established good predictive capacity of the chronic D. magna BLM is not affected. On the contrary, exposure to the highest dietary copper levels resulted in an increase of as much as 75% in growth and reproduction. To our knowledge, this is the first evidence that dietary copper exposure of a freshwater invertebrate feeding on a live diet resulted in a beneficial effect.

  1. Exposure assessment of dietary cadmium: findings from shanghainese over 40 years, China

    PubMed Central

    2013-01-01

    Background Environmental exposure to cadmium causes renal dysfunction and bone damage. Cadmium contamination in food is regarded as the main environmental source of non-occupational exposure. The aim of this study was to assess the contribution of dietary cadmium exposure in environmental cadmium exposure and its health risk among adults in Shanghai, China. Methods A cross-sectional survey about food consumption was conducted in 2008 among 207 citizens aged over 40 years in Shanghai, China. The food frequency questionnaire was combined with food, tobacco and water cadmium exposure to estimate the daily environmental cadmium exposure in both point and probabilistic estimations. Urine and blood samples of the participants were analyzed for internal exposure to total cadmium. Correlation analysis was conducted between the internal cadmium exposure and environmental cadmium exposure. Results According to the point estimation, average daily environmental cadmium exposure of the participants was 16.7 μg/day and approached 33.8% of the provisional tolerable daily intake (PTDI). Dietary and tobacco cadmium exposure approached 25.8% and 7.9% of the PTDI, respectively. Males had higher levels of dietary cadmium exposure than females (p?=?0.002). The probabilistic model showed that 93.4% of the population did not have any health risks from dietary cadmium exposure. By sensitivity analysis, tobacco consumption, tobacco cadmium level, cadmium in vegetables and cadmium in rice accounted for 27.5%, 24.9%, 20.2% and 14.6% of the total cadmium exposure, respectively. The mean values of urinary and blood cadmium among the study population were 0.5 μg/L and 1.9 μg/L, respectively. Positive correlations were observed between environmental cadmium exposure and blood cadmium (R?=?0.52, P<0.01), tobacco cadmium intake and blood cadmium excluding non-smokers (R?=?0.26, P?=?0.049<0.05), and urine cadmium and age (R?=?0.15, P?=?0.037). Conclusions It has been suggested that there is no

  2. Dietary exposure to aluminium and health risk assessment in the residents of Shenzhen, China.

    PubMed

    Yang, Mei; Jiang, Lixin; Huang, Huiping; Zeng, Shengbo; Qiu, Fen; Yu, Miao; Li, Xiaorong; Wei, Sheng

    2014-01-01

    Although there are great changes of dietary in the past few decades in China, few are known about the aluminium exposure in Chinese diet. The aim of this study is to systematically evaluate the dietary aluminium intake level in residents of Shenzhen, China. A total of 853 persons from 244 household were investigated their diet by three days food records. Finally, 149 kinds of foods in 17 food groups were selected to be the most consumed foods. From them, 1399 food samples were collected from market to test aluminium concentration. High aluminium levels were found in jellyfish (median, 527.5 mg/kg), fried twisted cruller (median, 466.0 mg/kg), shell (median, 107.1 mg/kg). The Shenzhen residents' average dietary aluminium exposure was estimated at 1.263 mg/kg bw/week which is lower than the PTWI (provisional tolerable weekly intake). But 0-2 and 3-13 age groups have the highest aluminium intake exceeding the PTWI (3.356 mg/kg bw/week and 3.248 mg/kg bw/week) than other age groups. And the main dietary aluminium exposure sources are fried twisted cruller, leaf vegetables and bean products. Our study suggested that even three decades rapid economy development, children in Shenzhen still have high dietary aluminium exposure risk. How to control high dietary aluminium exposure still is a great public health challenge in Shenzhen, China.

  3. Dietary Exposure to Aluminium and Health Risk Assessment in the Residents of Shenzhen, China

    PubMed Central

    Yang, Mei; Jiang, Lixin; Huang, Huiping; Zeng, Shengbo; Qiu, Fen; Yu, Miao; Li, Xiaorong; Wei, Sheng

    2014-01-01

    Although there are great changes of dietary in the past few decades in China, few are known about the aluminium exposure in Chinese diet. The aim of this study is to systematically evaluate the dietary aluminium intake level in residents of Shenzhen, China. A total of 853 persons from 244 household were investigated their diet by three days food records. Finally, 149 kinds of foods in 17 food groups were selected to be the most consumed foods. From them, 1399 food samples were collected from market to test aluminium concentration. High aluminium levels were found in jellyfish (median, 527.5 mg/kg), fried twisted cruller (median, 466.0 mg/kg), shell (median, 107.1 mg/kg). The Shenzhen residents' average dietary aluminium exposure was estimated at 1.263 mg/kg bw/week which is lower than the PTWI (provisional tolerable weekly intake). But 0–2 and 3–13 age groups have the highest aluminium intake exceeding the PTWI (3.356 mg/kg bw/week and 3.248 mg/kg bw/week) than other age groups. And the main dietary aluminium exposure sources are fried twisted cruller, leaf vegetables and bean products. Our study suggested that even three decades rapid economy development, children in Shenzhen still have high dietary aluminium exposure risk. How to control high dietary aluminium exposure still is a great public health challenge in Shenzhen, China. PMID:24594670

  4. FACTORS INFLUENCING TOTAL DIETARY EXPOSURE OF YOUNG CHILDREN

    EPA Science Inventory

    A deterministic model was developed to identify critical input parameters to assess dietary intake of young children. The model was used as a framework for understanding important factors in data collection and analysis. Factors incorporated included transfer efficiencies of pest...

  5. FACTORS INFLUENCING TOTAL DIETARY EXPOSURE OF YOUNG CHILDREN

    EPA Science Inventory

    A deterministic model was developed to identify critical input parameters to assess dietary intake of young children. The model was used as a framework for understanding important factors in data collection and analysis. Factors incorporated included transfer efficiencies of pest...

  6. Poor adherence to dietary guidelines among adult survivors of childhood acute lymphoblastic leukemia.

    PubMed

    Robien, Kim; Ness, Kirsten K; Klesges, Lisa M; Baker, K Scott; Gurney, James G

    2008-11-01

    Recent studies indicate that survivors of childhood acute lymphoblastic leukemia (ALL) are at increased risk of obesity and cardiovascular disease, conditions that healthy dietary patterns may help ameliorate or prevent. To evaluate the usual dietary intake of adult survivors of childhood ALL, food frequency questionnaire data were collected from 72 participants, and compared with the 2007 World Cancer Research Fund/American Institute for Cancer Research (WCRF/AICR) Cancer Prevention recommendations, the Dietary Approaches to Stop Hypertension (DASH) diet, and the 2005 United States Department of Agriculture (USDA) Food Guide. Mean daily energy intake was consistent with estimated requirements; however, mean body mass index was 27.1 kg/m2 (overweight). Dietary index scores averaged fewer than half the possible number of points on all 3 scales, indicating poor adherence to recommended guidelines. No study participant reported complete adherence to any set of guidelines. Although half the participants met minimal daily goals for 5 servings of fruits and vegetables (WCRF/AICR recommendations) and dietary fat (DASH diet and USDA Food Guide), participants reported dietary sodium and added sugar intake considerably in excess of recommendations, and suboptimal consumption of whole grains. Guideline adherence was not associated with either body mass index or waist circumference, perhaps due to the low dietary index scores. These findings suggest that dietary intake for many adult survivors of childhood ALL is not concordant with dietary recommendations that may help reduce their risk of obesity, cardiovascular disease, or other treatment-related late effects.

  7. Dietary exposure to aluminium of urban residents from cities in South China.

    PubMed

    Jiang, Qi; Wang, Jing; Li, Min; Liang, Xuxia; Dai, Guangwei; Hu, Zhikun; Wen, Jian; Huang, Qiong; Zhang, Yonghui

    2013-01-01

    A dietary survey was conducted over three consecutive days by using 24-hour dietary recall in the Pearl River Delta of South China to investigate the dietary consumption status. A total of 1702 food samples, 22 food groups, were collected, and aluminium concentrations of foods were determined by using ICP-MS. Weekly dietary exposure to aluminium of the average urban residents of South China was estimated to be 1.5 mg kg⁻¹ body weight, which amounted to 76% of the provisional tolerable weekly intake. Wheat-made products (53.5%) contributed most to the dietary exposure, followed by vegetables (12.2%). The high-level consumers' weekly exposure to aluminium was 11.1 mg kg⁻¹ body weight, which amounted to 407% of the provisional tolerable weekly intake. The results indicated that the general urban residents in South China might be safe from aluminium exposure, but the high-level consumers might be at some risk of aluminium exposure. The foods contributing to aluminium exposure were processed food with aluminium-containing food additives. It is necessary to take effective measures to control the overuse of aluminium-containing food additives.

  8. Acute physiologic effects of secondhand smoke exposure in children.

    PubMed

    Moss, Deborah R; Lucht, Lorrie A; Kip, Kevin E; Reis, Steven E

    2010-07-01

    We investigated the hypothesis that exhaled carbon monoxide (eCO), heart rate (HR), and blood pressure (BP) would increase acutely in exposed but not in unexposed children. In a nonrandomized controlled design, parent-child dyads were assigned to groups based on exposure: child subjects, 7-18 years of age, exposed to smoking daily in the home (exposed) or with no household exposure (unexposed control). HR, BP, and eCO were measured before and after exposure to a parent smoking 1 cigarette (exposed) or a time-lapse equivalent (control). The primary analysis compared mean acute changes in physiological measures following intervention or control procedure. Forty-one dyads were enrolled. At baseline, no differences in child gender, race, ethnicity, HR, BP, lipids, or fasting glucose were noted between exposure groups. Following experimental or control procedures, the median change in eCO was similar between groups (-0.1 ppm exposed vs. 0.0 ppm unexposed, p = .27). Acute hemodynamic changes were also similar between exposed and unexposed children, respectively: (HR change 4.2 vs. 2.6 beats per minute, p = .62; systolic blood pressure change 0.08 vs. 0.41 mm Hg, p = .91; diastolic blood pressure 0.08 vs. 2.27 mm Hg, p = .37). This is the first study to report on acute physiologic changes of secondhand smoke exposure in children in a naturalistic setting. A single acute dose of passive smoke exposure in children did not alter the physiologic variables of HR or BP. Further in-home study using continuous monitoring is needed. Demonstration of acute effects may serve as clinical feedback to motivate parents to quit smoking.

  9. Dietary exposure to aflatoxin and fumonisin among Tanzanian children as determined using biomarkers of exposure

    PubMed Central

    Shirima, Candida P.; Kimanya, Martin E.; Kinabo, Joyce L.; Routledge, Michael N.; Srey, Chou; Wild, Christopher P.; Gong, Yun Yun

    2014-01-01

    Scope The study aims to evaluate the status of dietary exposure to aflatoxin and fumonisin in young Tanzanian children, using previously validated biomarkers of exposure. Methods and results A total of 148 children aged 12 to 22 months, were recruited from three geographically distant villages in Tanzania; Nyabula, Kigwa and Kikelelwa. Plasma aflatoxin-albumin adducts (AF-alb) and urinary fumonisin B1 (UFB1) were measured by ELISA and LC-MS, respectively. AF-alb was detectable in 84% of children, was highest in fully weaned children (p<0.01) with higher levels being associated with higher maize intake (p<0.05). AF-alb geometric mean (95% CI) was 43.2 (28.7–65.0), 19.9 (13.5–29.2) and 3.6 (2.8–4.7) pg/mg albumin in children from Kigwa, Nyabula and Kikelelwa, respectively. UFB1 was detectable in 96% of children and the level was highest in children who had been fully weaned (p<0.01). The geometric UFB1 mean (95% CI) was 327.2 (217.1–493.0), 211.7 (161.1–278.1) and 82.8 (58.3–117.7) pg/ml in Kigwa, Nyabula and Kikelelwa, respectively. About 82% of all the children were exposed to both mycotoxins. Conclusion Young children in Tanzania are chronically exposed to both aflatoxin and fumonisin through contaminated diet, although the level of exposure varies markedly between the three villages studied. PMID:23776058

  10. Pulmonary Inflammatory Responses to Acute Meteorite Dust Exposures - to Acute Meteorite Dust Exposures - Exploration

    NASA Technical Reports Server (NTRS)

    Harrington, A. D.; McCubbin, F. M.; Kaur, J.; Smirnov, A.; Galdanes, K.; Schoonen, M. A. A.; Chen, L. C.; Tsirka, S. E.; Gordon, T.

    2017-01-01

    New initiatives to begin lunar and martian colonization within the next few decades are illustrative of the resurgence of interest in space travel. One of NASA's major concerns with extended human space exploration is the inadvertent and repeated exposure to unknown dust. This highly interdisciplinary study evaluates both the geochemical reactivity (e.g. iron solubility and acellular reactive oxygen species (ROS) generation) and the relative toxicity (e.g. in vitro and in vivo pulmonary inflammation) of six meteorite samples representing either basalt or regolith breccia on the surface of the Moon, Mars, and Asteroid 4Vesta. Terrestrial mid-ocean ridge basalt (MORB) is also used for comparison. The MORB demonstrated higher geochemical reactivity than most of the meteorite samples but caused the lowest acute pulmonary inflammation (API). Notably, the two martian meteorites generated some of the highest API but only the basaltic sample is significantly reactive geochemically. Furthermore, while there is a correlation between a meteorite's soluble iron content and its ability to generate acellular ROS, there is no direct correlation between a particle's ability to generate ROS acellularly and its ability to generate API. However, assorted in vivo API markers did demonstrate strong positive correlations with increasing bulk Fenton metal content. In summary, this comprehensive dataset allows for not only the toxicological evaluation of astromaterials but also clarifies important correlations between geochemistry and health.

  11. Risk assessment of dietary exposure to aluminium in the Chinese population.

    PubMed

    Ma, Ning; Liu, Zhao-Ping; Yang, Da-Jin; Liang, Jiang; Zhu, Jiang-Hui; Xu, Hai-Bin; Li, Feng-Qin; Li, Ning

    2016-10-01

    In order to address the issue of excessive intake of aluminium (Al) from Al-containing food additives in the Chinese diet, this study conducted a dietary exposure assessment of Al in the general population based on the national surveillance data of Al content in foods and national food consumption data. It was found that the mean dietary exposure of the whole Chinese population to Al from Al-containing food additives was 1.795 mg kg(‒1) bw week(‒1), not exceeding the PTWI, while high dietary exposures (e.g., 97.5(th) percentile) to Al were 7.660 and 2.103-2.903 mg kg(‒1) bw week(‒1) for children, respectively, both exceeding the PTWI. It was found that the dietary exposure to Al for 32.5% of the total Chinese population and 42.6% of children aged 4-6 years exceeded the PTWI. Wheat flour and wheat-based products are the main source of dietary A l exposure (85% of the total intake); and puffed foods are the major source of Al intake for children. These findings suggested that consumption of Al-containing food additives could be a health concern for consumers with high food consumption (97.5(th) percentile) and children under the age of 14 years.

  12. Dietary exposure to acrylamide from potato crisps to the Spanish population.

    PubMed

    Arribas-Lorenzo, G; Morales, F J

    2009-03-01

    Potato crisps are one of the food commodities that contribute most to overall dietary human exposure of acrylamide. This investigation has estimated the dietary exposure to acrylamide form potato crisps in the Spanish population. Sampling of potato crisps (n = 36) from 16 different producers were carried out in March 2008. An average level of 740 microg kg(-1) (ranging from 81 to 2622 microg kg(-1); minimum to maximum) and a median of 592 microg kg(-1) were obtained. Acrylamide levels in marketed potato crisps have been significantly reduced (nearly to 50%) compared with a previous sampling performed 4 years earlier. The observed signal value (90th percentile) was 1377 microg kg(-1) with 86% of the samples with acrylamide levels lower than 1000 microg kg(-1). Dietary exposure to acrylamide from potato crisp consumption in the total Spanish population was estimated to be 0.042 microg kg(-1) body weight day(-1) by using a deterministic approach based on the National consumption database. In a second study, dietary exposure (based on a 3-day food record) was determined to be 0.053 microg kg(-1) body weight day(-1) for the adult population (17-60 years) and 0.142 microg kg(-1) body weight day(-1) for children (7-12 years). The contribution of potato crisps to the estimated dietary acrylamide exposure of the Spanish population is moderate as compared with other European Member States.

  13. FACTORS INFLUENCING TOTAL DIETARY EXPOSURES OF YOUNG CHILDREN

    EPA Science Inventory

    A deterministic model was developed to identify the critical input parameters needed to assess dietary intakes of young children. The model was used as a framework for understanding the important factors in data collection and data analysis. Factors incorporated into the model i...

  14. FACTORS INFLUENCING TOTAL DIETARY EXPOSURES OF YOUNG CHILDREN

    EPA Science Inventory

    A deterministic model was developed to identify the critical input parameters needed to assess dietary intakes of young children. The model was used as a framework for understanding the important factors in data collection and data analysis. Factors incorporated into the model i...

  15. Lung function after acute chlorine exposure

    SciTech Connect

    Jones, R.N.; Hughes, J.M.; Glindmeyer, H.; Weill, H.

    1986-12-01

    Chlorine gas, spreading from a train derailment, caused the deaths of 8 persons and the hospitalization of 23 with sublethal respiratory injuries. Twenty-five others had at least one sign of lower respiratory abnormality but were not hospitalized. One hundred thirteen who were examined for gas effects in the forty-eight hours after exposure, including 20 of 23 of those hospitalized and 21 of 25 of those not hospitalized but with respiratory abnormality, participated in follow-up studies. Probability of admission to hospital was related to distance from the spill, but by 3 wk after exposure there was no detectable difference in lung function relating to distance or apparent severity of injury. In 60 adults tested multiple times over the following 6 yr, longitudinal change in lung function showed expected differences related to smoking but none related to distance or severity of injury. The average annual change in FEV was -34 ml/yr in current smokers and -18 ml/yr in ex and never-smokers. The lack of a discernible chlorine effect in this cohort accords with the findings in most previous studies. Without pre-exposure measurements, a single, lasting reduction in lung function cannot be excluded, but there is no evidence for a persisting abnormal rate of decline.

  16. Dietary exposure to selected perfluoroalkyl acids (PFAAs) in four European regions.

    PubMed

    Klenow, Stefanie; Heinemeyer, Gerhard; Brambilla, Gianfranco; Dellatte, Elena; Herzke, Dorte; de Voogt, Pim

    2013-01-01

    The dietary exposure to selected PFAAs was estimated in four selected European states (Belgium, the Czech Republic, Italy and Norway) representing Western, Southern, Eastern and Northern Europe. The harmonised sampling programme designed in the European Union project PERFOOD was targeted at identifying seven selected PFAAs, including perfluorooctane sulfonic acid (PFOS) and perfluorooctanoic acid (PFOA), in food items that are most important both in terms of consumption and based on known high contamination patterns. The estimated average dietary exposure for adults (18-64 years) and children (3-9 years) is generally below or close to 1 ng kg⁻¹ BW day⁻¹ for all seven PFAAs. Considering the high consumption of food groups that contribute most to the exposure does not result in estimates exceeding 4 ng kg⁻¹ BW day⁻¹. Thus, based on the TDIs proposed by EFSA for PFOS (150 ng kg⁻¹ BW day⁻¹) and PFOA (1500 ng kg⁻¹ BW day⁻¹), no concern can be identified. There are distinct dietary exposure patterns from region to region as a result of different food consumption and contamination patterns. Foods of plant origin (e.g. fruit and vegetables) are most important for the dietary exposure to PFHxA, PFOA and PFHxS, while the consumption of foods of animal origin (particularly fish and seafood) mostly contributes to the dietary exposure to PFDA and PFUnDA. For the dietary exposure to PFNA and PFOS, food of animal and plant origin contributes with equal importance. In conclusion, region-to-region differences as well as the relative importance of food of different origin for each PFAA should be paid more attention in further research.

  17. Development of acute exposure guideline levels for airborne exposures to hazardous substances.

    PubMed

    Krewski, Daniel; Bakshi, Kulbir; Garrett, Roger; Falke, Ernest; Rusch, George; Gaylor, David

    2004-04-01

    Hazardous substances can be released into the atmosphere due to industrial and transportation accidents, fires, tornadoes, earthquakes, and terrorists, thereby exposing workers and the nearby public to potential adverse health effects. Various enforceable guidelines have been set by regulatory agencies for worker and ambient air quality. However, these exposure levels generally are not applicable to rare lifetime acute exposures, which possibly could occur at high concentrations. Acute exposure guideline levels (AEGLs) provide estimates of concentrations for airborne exposures for an array of short durations that possibly could cause mild (AEGL-1), severe, irreversible, potentially disabling adverse health effects (AEGL-2), or life threatening effects (AEGL-3). These levels can be useful for emergency responders and planners in reducing or eliminating potential risks to the public. Procedures and methodologies for deriving AEGLs are reviewed in this paper that have been developed in the United States, with direct input from international representatives of OECD member-countries, by the National Advisory Committee for Acute Exposure Guidelines for Hazardous Substances and reviewed by the National Research Council. Techniques are discussed for the extrapolation of effects across different exposure durations. AEGLs provide a viable approach for assisting in the prevention, planning, and response to acute airborne exposures to toxic agents.

  18. Reduced Foodborne Toxin Exposure Is a Benefit of Improving Dietary Diversity

    PubMed Central

    Wu, Felicia; Mitchell, Nicole J.; Male, Denis; Kensler, Thomas W.

    2014-01-01

    Naturally occurring foodborne toxins are common in subsistence diets of low-income human populations worldwide. Often, these populations rely on one or two staple foods for the bulk of their calories, making them more susceptible to chronic intake of certain toxins. Exposure to common foodborne toxins is associated with diverse conditions such as cancer, immunotoxicity, growth impairment, and neurological deficits. Interventions focused solely on reducing toxin levels have proven difficult to sustain. Using case studies of two foodborne toxins, aflatoxin and cassava cyanide, this article addresses the heightened risk of particular diseases from eating monotonous diets based in maize, groundnuts, and cassava: common in sub-Saharan Africa and parts of Asia. We also discuss the potential role of increased dietary diversity in counteracting these diseases. Increased dietary diversity can reduce consumption of toxins and increase intake of nutrients that could counteract the toxicity of such chemicals. In Qidong, China, a population that previously consumed a monotonous maize-based diet and increased dietary diversity since the 1980s has experienced a dramatic reduction in liver cancer mortalities. That liver cancer decreased as dietary diversity increased is the catalyst for the hypothesis that dietary diversity could have a direct impact on reducing health effects of foodborne toxins. Future research, agricultural development, and food policy reforms should take into consideration the multifaceted benefits associated with improved dietary diversity. Collaborations between toxicologists, nutritionists, and policymakers are important to development of sustainable interventions to reduce foodborne toxin exposure and promote health through increased dietary diversity. PMID:25015663

  19. Biomarkers of Acute Respiratory Allergen Exposure: Screening For Sensitization Potential

    EPA Science Inventory

    Rationale: An in vitro assay to identify respiratory sensitizers will provide a rapid screen and reduce animal use. The study goal was to identify biomarkers that differentiate allergen versus non-allergen responses following an acute exposure. Methods: Female BALB/c mice rec...

  20. Biomarkers of Acute Respiratory Allergen Exposure: Screening For Sensitization Potential

    EPA Science Inventory

    Rationale: An in vitro assay to identify respiratory sensitizers will provide a rapid screen and reduce animal use. The study goal was to identify biomarkers that differentiate allergen versus non-allergen responses following an acute exposure. Methods: Female BALB/c mice rec...

  1. EFFECTS OF ACUTE PYRETHROID EXPOSURE ON THERMOREGULATION IN RATS.

    EPA Science Inventory

    Pyrethroid insecticides produce acute neurotoxicity in mammals. According to the FQPA mandate, the USEPA is required to consider the risk of cumulative toxicity posed to humans through exposure to pyrethroid mixtures. Thermoregulatory response (TR) is being used to determine if t...

  2. Health Impacts from Acute Radiation Exposure

    SciTech Connect

    Strom, Daniel J.

    2003-09-30

    Absorbed doses above1-2 Gy (100-200 rads) received over a period of a day or less lead to one or another of the acute radiation syndromes. These are the hematopoietic syndrome, the gastrointestinal (GI) syndrome, the cerebrovascular (CV) syndrome, the pulmonary syndrome, or the cutaneous syndrome. The dose that will kill about 50% of the exposed people within 60 days with minimal medical care, LD50-60, is around 4.5 Gy (450 rads) of low-LET radiation measured free in air. The GI syndrome may not be fatal with supportive medical care and growth factors below about 10 Gy (1000 rads), but above this is likely to be fatal. Pulmonary and cutaneous syndromes may or may not be fatal, depending on many factors. The CV syndrome is invariably fatal. Lower acute doses, or protracted doses delivered over days or weeks, may lead to many other health outcomes than death. These include loss of pregnancy, cataract, impaired fertility or temporary or permanent sterility, hair loss, skin ulceration, local tissue necrosis, developmental abnormalities including mental and growth retardation in persons irradiated as children or fetuses, radiation dermatitis, and other symptoms listed in Table 2 on page 12. Children of parents irradiated prior to conception may experience heritable ill-health, that is, genetic changes from their parents. These effects are less strongly expressed than previously thought. Populations irradiated to high doses at high dose rates have increased risk of cancer incidence and mortality, taken as about 10-20% incidence and perhaps 5-10% mortality per sievert of effective dose of any radiation or per gray of whole-body absorbed dose low-LET radiation. Cancer risks for non-uniform irradiation will be less.

  3. Levels of preservatives (sulfite, sorbate and benzoate) in New Zealand foods and estimated dietary exposure.

    PubMed

    Cressey, P; Jones, S

    2009-05-01

    Thirty foods assessed as being the likely major contributors to dietary preservative exposure were purchased, prepared as normally consumed and analyzed for sulfite, sorbate and benzoate. The majority of preservative concentrations (>98%) were within maximum permitted levels (MPLs) specified in the Australia New Zealand Food Standards Code. Mean population level estimates of dietary exposure were well below the respective acceptable daily intakes (ADIs) for all age-gender groups for all preservatives at 7-27%, 1-4% and 1-8% of the ADI for sulfites, sorbates and benzoates, respectively. All population level 95th percentile estimates of dietary exposure were below the ADI, with the exception of estimates for sulfite exposure for 5-12-year-old boys. The results of the current survey indicate that dietary exposure to the preservatives, sulfite, sorbate and benzoate, represent a low level of public health risk. However, it should be noted that the exposure estimates determined in the current survey will be influenced by the assumptions made.

  4. Assessing and reporting uncertainties in dietary exposure analysis: Mapping of uncertainties in a tiered approach.

    PubMed

    Kettler, Susanne; Kennedy, Marc; McNamara, Cronan; Oberdörfer, Regina; O'Mahony, Cian; Schnabel, Jürgen; Smith, Benjamin; Sprong, Corinne; Faludi, Roland; Tennant, David

    2015-08-01

    Uncertainty analysis is an important component of dietary exposure assessments in order to understand correctly the strength and limits of its results. Often, standard screening procedures are applied in a first step which results in conservative estimates. If through those screening procedures a potential exceedance of health-based guidance values is indicated, within the tiered approach more refined models are applied. However, the sources and types of uncertainties in deterministic and probabilistic models can vary or differ. A key objective of this work has been the mapping of different sources and types of uncertainties to better understand how to best use uncertainty analysis to generate more realistic comprehension of dietary exposure. In dietary exposure assessments, uncertainties can be introduced by knowledge gaps about the exposure scenario, parameter and the model itself. With this mapping, general and model-independent uncertainties have been identified and described, as well as those which can be introduced and influenced by the specific model during the tiered approach. This analysis identifies that there are general uncertainties common to point estimates (screening or deterministic methods) and probabilistic exposure assessment methods. To provide further clarity, general sources of uncertainty affecting many dietary exposure assessments should be separated from model-specific uncertainties.

  5. Acute exposure to environmental tobacco smoke and heart rate variability.

    PubMed Central

    Pope, C A; Eatough, D J; Gold, D R; Pang, Y; Nielsen, K R; Nath, P; Verrier, R L; Kanner, R E

    2001-01-01

    Environmental tobacco smoke (ETS) has been associated with cardiovascular mortality. Pathophysiologic pathways leading from ETS exposure to cardiopulmonary disease are still being explored. Reduced cardiac autonomic function, as measured by heart rate variability (HRV), has been associated with cardiac vulnerability and may represent an important pathophysiologic mechanism linking ETS and risk of cardiac mortality. In this study we evaluated acute ETS exposure in a commercial airport with changes in HRV in 16 adult nonsmokers. We conducted ambulatory electrocardiographic (ECG) monitoring for 8-hr periods while participants alternated 2 hr in nonsmoking and smoking areas. Nicotine and respirable suspended particle concentrations and participants' blood oxygen saturation were also monitored. We calculated time and frequency domain measures of HRV for periods in and out of the smoking area, and we evaluated associations with ETS using comparative statistics and regression modeling. ETS exposure was negatively associated with all measures of HRV. During exposure periods, we observed an average decrement of approximately 12% in the standard deviation of all normal-to-normal heart beat intervals (an estimate of overall HRV). ETS exposures were not associated with mean heart rate or blood oxygen saturation. Altered cardiac autonomic function, assessed by decrements in HRV, is associated with acute exposure to ETS and may be part of the pathophysiologic mechanisms linking ETS exposure and increased cardiac vulnerability. PMID:11485870

  6. Acute pancreatitis attributed to dietary indiscretion in a female mixed breed canine.

    PubMed

    Shukla, Angelie

    2010-02-01

    A female, mixed-breed dog was presented with signs of abdominal discomfort and vomiting of 24 h duration following an episode of dietary indiscretion. Clinical signs, previous medical history, and diagnostic tests supported a diagnosis of acute pancreatitis. Specific and supportive treatment was instituted, and clinical signs resolved 10 d after presentation.

  7. [Dietary exposure assessment of aflatoxin of foodstuff and edible oil from Shenzhen residents].

    PubMed

    Li, Ke; Qiu, Fen; Jiang, Lixin; Yang, Mei

    2014-07-01

    To assess the dietary exposure aflatoxin B1 and total aflatoxins of foodstuff and edible oil in Shenzhen residents. Aflatoxins in the samples were determined by the immuno-affinity column clean-up plus UPLC. The aflatoxin B1 and aflatoxins dietary exposure were calculated by the level of aflatoxins contamination in the food and consumption of dietary. The average diary aflatoxin B1 dietary exposure of the man of the 2 to 6, 7 to 14, 15 to 50 and > 50 age group in Shenzhen were 0.320, 0.385, 0.401 and 0.398 ng/(kg BW x d), the results of the woman were 0.282, 0.222, 0.367 and 0.470 ng/(kg BW x d) respectively. The total average daily dietary aflatoxin B1 exposure of the man were 0.012, 0.015, 0.016 and 0.016 ng/(kg BW x d) about each age group. The results of the woman were 78.4, 167, 113 and 103 ng/(kg BW d). According to the the average levels of consumption and the high levels of consumption, the risk of AFB, of the man were 0.012,0.015, 0.016, 0. 016 and 3.0, 8.2, 4.1, 4.4 cancer patient per one hundred thousand, respectively. The results of the woman were 0.010, 0.009, 0.014, 0.018 and 2.9, 6.7, 4.4, 4.0 cancer patient per one hundred thousand, respectively. 7 to 14 age group compared with adults age group face higher exposure levels. The rice and peanut oil are most primary aflatoxin dietary exposure sources in Shenzhen.

  8. Acute inhalation exposure of azodicarbonamide in the guinea pig.

    PubMed

    Shopp, G M; Cheng, Y S; Gillett, N A; Bechtold, W E; Medinsky, M A; Hobbs, C H; Birnbaum, L S; Mauderly, J L

    1987-02-01

    Humans have been exposed to azodicarbonamide (ADA) by inhalation where bulk quantities of ADA are handled in the workplace. Responses of some workers have led to concern for the potential irritant and sensitizing properties of inhaled ADA. This study examined the effects of inhaling ADA on lung structure and function of guinea pigs during and after an acute exposure. Groups of 20 guinea pigs were exposed to each of 3 concentrations of ADA (19, 58, and 97 mg/m3), plus air as a control, for 1 hr. Pulmonary function was measured before exposure (baseline), during exposure, immediately after exposure and 24 hr after exposure. Dynamic compliance (Cdyn), total pulmonary resistance (RL), tidal volume (VT), respiratory frequency and minute volume were measured. In addition, gross necropsies and histological examinations of respiratory tract tissues were done either immediately following the exposure or 24 hr after exposure. There were no effects of ADA exposure on gross necropsy, histology, Cdyn, or RL. Some significant, concentration-related decreases in VT, respiratory frequency and minute volume were seen. The magnitudes of these changes were small: the largest change was seen in minute volume, amounting to a 24% decrease in the high concentration group. Inhalation exposure of guinea pigs to ADA at concentrations of up to 97 mg/m3 resulted in minor changes in pulmonary function without any changes in lung histology.

  9. Low-level arsenic exposure: nutritional and dietary predictors in first-grade Uruguayan children

    PubMed Central

    Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

    2016-01-01

    Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5–8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-hour dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9 µg/L) and household water (water As: median 0.45 µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on ”nutrient dense” dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity. PMID:26828624

  10. Low-level arsenic exposure: Nutritional and dietary predictors in first-grade Uruguayan children.

    PubMed

    Kordas, Katarzyna; Queirolo, Elena I; Mañay, Nelly; Peregalli, Fabiana; Hsiao, Pao Ying; Lu, Ying; Vahter, Marie

    2016-05-01

    Arsenic exposure in children is a public health concern but is understudied in relation to the predictors, and effects of low-level exposure. We examined the extent and dietary predictors of exposure to inorganic arsenic in 5-8 year old children from Montevideo, Uruguay. Children were recruited at school; 357 were enrolled, 328 collected morning urine samples, and 317 had two 24-h dietary recalls. Urinary arsenic metabolites, i.e. inorganic arsenic (iAs), methylarsonic acid (MMA), and dimethylarsinic acid (DMA), were measured using high-performance liquid chromatography with hydride generation and inductively coupled plasma mass spectrometry (HPLC-HG-ICP-MS), and the sum concentration (U-As) used for exposure assessment. Proportions of arsenic metabolites (%iAs, %MMA and %DMA) in urine were modelled in OLS regressions as functions of food groups, dietary patterns, nutrient intake, and nutritional status. Exposure to arsenic was low (median U-As: 9.9µg/L) and household water (water As: median 0.45µg/L) was not a major contributor to exposure. Children with higher consumption of rice had higher U-As but lower %iAs, %MMA, and higher %DMA. Children with higher meat consumption had lower %iAs and higher %DMA. Higher scores on "nutrient dense" dietary pattern were related to lower %iAs and %MMA, and higher %DMA. Higher intake of dietary folate was associated with lower %MMA and higher %DMA. Overweight children had lower %MMA and higher %DMA than normal-weight children. In summary, rice was an important predictor of exposure to inorganic arsenic and DMA. Higher meat and folate consumption, diet rich in green leafy and red-orange vegetables and eggs, and higher BMI contributed to higher arsenic methylation capacity.

  11. Gastric acid response to acute exposure to hypergravity

    PubMed Central

    Yoon, Gun; Kim, Hyun-Soo

    2017-01-01

    The influence of environmental stressors on the pathogenesis of gastrointestinal disease has received increased awareness. Stress affects different physiological functions of the gastrointestinal tract, including gastric acid secretion and mucosal blood flow. Repeated exposures of rapid-onset, highly-sustained hypergravity cause severe physical stress in the pilot. Although the effects of exposure to hypergravity on cardiovascular and cerebral functions have been the subjects of numerous studies, crucial information regarding pathophysiological changes in the gastrointestinal tract following hypergravity exposure is lacking. In this study, we investigated the effects of acute exposure to hypergravity on gastric secretory activity and gastrin release. Male Sprague-Dawley rats were exposed to +10Gz three times for 3 min. Gastric juice and blood were collected. The volume and total acidity of gastric juice, and the plasma gastrin level was measured. Acute exposure to +10Gz significantly decreased the gastric juice parameters. The gastric juice volume and total acidity of hypergravity-exposed rats were 3.54 ± 0.32 mL/100 g and 84.90 ± 5.17 mEq/L, respectively, which were significantly lower than those of the nonexposed rats (4.62 ± 0.39 mL/100 g and 97.37 ± 5.42 mEq/L; P < 0.001 and P < 0.001, respectively). In contrast, plasma gastrin level was not significantly altered following hypergravity exposure. We demonstrated that acute exposure to hypergravity led to a significant decrease in the gastric juice volume and acidity but did not alter the plasma gastrin level. PMID:27992379

  12. Inhalation and Dietary Exposure to PCBs in Urban and Rural Cohorts via Congener-Specific Measurements

    PubMed Central

    2015-01-01

    Polychlorinated biphenyls (PCBs) are a group of 209 persistent organic pollutants, whose documented carcinogenic, neurological, and respiratory toxicities are expansive and growing. However, PCB inhalation exposure assessments have been lacking for North American ambient conditions and lower-chlorinated congeners. We assessed congener-specific inhalation and dietary exposure for 78 adolescent children and their mothers (n = 68) in the Airborne Exposure to Semi-volatile Organic Pollutants (AESOP) Study. Congener-specific PCB inhalation exposure was modeled using 293 measurements of indoor and outdoor airborne PCB concentrations at homes and schools, analyzed via tandem quadrupole GS-MS/MS, combined with questionnaire data from the AESOP Study. Dietary exposure was modeled using Canadian Total Diet Survey PCB concentrations and National Health and Nutrition Examination Survey (NHANES) food ingestion rates. For ∑PCB, dietary exposure dominates. For individual lower-chlorinated congeners (e.g., PCBs 40+41+71, 52), inhalation exposure was as high as one-third of the total (dietary+inhalation) exposure. ∑PCB inhalation (geometric mean (SE)) was greater for urban mothers (7.1 (1.2) μg yr–1) and children (12.0 (1.2) μg yr–1) than for rural mothers (2.4 (0.4) μg yr–1) and children (8.9 (0.3) μg yr–1). Schools attended by AESOP Study children had higher indoor PCB concentrations than did homes, and account for the majority of children’s inhalation exposure. PMID:25510359

  13. Arsenic exposure, dietary patterns, and skin lesion risk in bangladesh: a prospective study.

    PubMed

    Pierce, Brandon L; Argos, Maria; Chen, Yu; Melkonian, Stephanie; Parvez, Faruque; Islam, Tariqul; Ahmed, Alauddin; Hasan, Rabiul; Rathouz, Paul J; Ahsan, Habibul

    2011-02-01

    Dietary factors are believed to modulate arsenic toxicity, potentially influencing risk of arsenical skin lesions. The authors evaluated associations among dietary patterns, arsenic exposure, and skin lesion risk using baseline food frequency questionnaire data collected in the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh (2000-2009). They identified dietary patterns and estimated dietary pattern scores using factor analysis. Scores were tested for association with incident skin lesion risk and interaction with water arsenic exposure by using ∼6 years of follow-up data (814 events among 9,677 individuals) and discrete time hazards models (adjusting for key covariates). The authors identified 3 clear dietary patterns: the "gourd and root," "vegetable," and "animal protein" patterns. The gourd and root pattern score was inversely associated with skin lesion risk (P(trend) = 0.001), with hazard ratios of 0.86, 0.73, and 0.69 for the second, third, and fourth highest quartiles. Furthermore, the association between water arsenic and skin lesion incidence was stronger among participants with low gourd and root scores (multiplicative P(interaction) < 0.001; additive P(interaction) = 0.05). The vegetable pattern and animal protein pattern showed similar but weaker associations and interactions. Eating a diet rich in gourds and root vegetables and increasing dietary diversity may reduce arsenical skin lesion risk in Bangladesh.

  14. Arsenic Exposure, Dietary Patterns, and Skin Lesion Risk in Bangladesh: A Prospective Study

    PubMed Central

    Pierce, Brandon L.; Argos, Maria; Chen, Yu; Melkonian, Stephanie; Parvez, Faruque; Islam, Tariqul; Ahmed, Alauddin; Hasan, Rabiul; Rathouz, Paul J.; Ahsan, Habibul

    2011-01-01

    Dietary factors are believed to modulate arsenic toxicity, potentially influencing risk of arsenical skin lesions. The authors evaluated associations among dietary patterns, arsenic exposure, and skin lesion risk using baseline food frequency questionnaire data collected in the Health Effects of Arsenic Longitudinal Study (HEALS) in Araihazar, Bangladesh (2000–2009). They identified dietary patterns and estimated dietary pattern scores using factor analysis. Scores were tested for association with incident skin lesion risk and interaction with water arsenic exposure by using ∼6 years of follow-up data (814 events among 9,677 individuals) and discrete time hazards models (adjusting for key covariates). The authors identified 3 clear dietary patterns: the “gourd and root,” “vegetable,” and “animal protein” patterns. The gourd and root pattern score was inversely associated with skin lesion risk (Ptrend = 0.001), with hazard ratios of 0.86, 0.73, and 0.69 for the second, third, and fourth highest quartiles. Furthermore, the association between water arsenic and skin lesion incidence was stronger among participants with low gourd and root scores (multiplicative Pinteraction < 0.001; additive Pinteraction = 0.05). The vegetable pattern and animal protein pattern showed similar but weaker associations and interactions. Eating a diet rich in gourds and root vegetables and increasing dietary diversity may reduce arsenical skin lesion risk in Bangladesh. PMID:21178101

  15. PRN 2000-7: Non-Dietary Exposure Task Force

    EPA Pesticide Factsheets

    This PR Notice announces an industry-wide task force to jointly develop residential indoor exposure data for pesticides containing one or more of the active ingredients synthetic pyrethroids, pyrethrum and synergists.

  16. Metal trophic transfer from algae to cladocerans and the relative importance of dietary metal exposure.

    PubMed

    Sofyan, Agus; Shaw, Joseph R; Birge, Wesley J

    2006-04-01

    We initially investigated effects and uptake of cadmium and copper on Pseudokirchneriella subcapitata (primary producer; formerly known as Selenastrum capricornutum). Our major efforts focused on the effects of metal-laden (i.e., Cd, Cu) P. subcapitata when used to provide dietary metal exposure to Ceriodaphnia dubia (primary consumer). Major test endpoints included feeding rate, survival, and reproduction. Metal body burden in C. dubia increased dose dependently at dietary exposure concentrations of 0.6 microg/g algal dry weight or less for cadmium and 74.7 microg/g algal dry weight or less for copper. However, it decreased sharply when dietary concentrations exceeded 0.6 microg/g algal dry weight for cadmium and 74.7 microg/g algal dry weight copper. Both dietary cadmium and copper affected all the major test endpoints. Whereas reproduction was observed to be the most sensitive endpoint, survival was observed to be the least sensitive endpoint. These results demonstrated the potential importance of dietary exposure for consideration in metal regulations or risk assessment.

  17. Human physiological responses to cold exposure: Acute responses and acclimatization to prolonged exposure.

    PubMed

    Castellani, John W; Young, Andrew J

    2016-04-01

    Cold exposure in humans causes specific acute and chronic physiological responses. This paper will review both the acute and long-term physiological responses and external factors that impact these physiological responses. Acute physiological responses to cold exposure include cutaneous vasoconstriction and shivering thermogenesis which, respectively, decrease heat loss and increase metabolic heat production. Vasoconstriction is elicited through reflex and local cooling. In combination, vasoconstriction and shivering operate to maintain thermal balance when the body is losing heat. Factors (anthropometry, sex, race, fitness, thermoregulatory fatigue) that influence the acute physiological responses to cold exposure are also reviewed. The physiological responses to chronic cold exposure, also known as cold acclimation/acclimatization, are also presented. Three primary patterns of cold acclimatization have been observed, a) habituation, b) metabolic adjustment, and c) insulative adjustment. Habituation is characterized by physiological adjustments in which the response is attenuated compared to an unacclimatized state. Metabolic acclimatization is characterized by an increased thermogenesis, whereas insulative acclimatization is characterized by enhancing the mechanisms that conserve body heat. The pattern of acclimatization is dependent on changes in skin and core temperature and the exposure duration. Published by Elsevier B.V.

  18. Effects of dietary selenium exposure in captive American common eiders

    USGS Publications Warehouse

    Franson, J.C.; Hoffman, D.J.; Wells-Berlin, A. M.; Perry, M.C.; Bochsler, V.S.; Finley, D.L.; Flint, P.L.; Hollmen, T.

    2005-01-01

    We conducted two studies of Se exposure in captive common eiders (Somateria mollissima). In Study 1, eiders were fed diets with added Se (as L-selenomethionine) in concentrations increasing from 10 ppm to 80 ppm. In Study 2, eiders received control, low exposure (20 ppm Se), and high exposure (60 ppm Se) diets. One duck in the high exposure group in Study 2 died after 36 days. Remaining high exposure ducks in Study 2 and ducks in Study 1 were euthanized after losing 25-30% of their body weight, which occurred after 41 days and 60-78 days, respectively. Body weights did not differ between control and low exposure ducks in Study 2. At the end of Study 1, the mean Se concentration in blood was 32 ppm wet weight (ww). In Study 2, mean blood Se reached 14 ppm ww in the low exposure group and 17 ppm ww in high exposure ducks. Mean Se concentrations in liver were 1252 ppm dry weight (dw) in Study 1, and 351 and 735 ppm dw, respectively, in the low and high exposure groups of Study 2. Oxidative stress was evidenced by Se-associated effects on glutathione metabolism, but not entirely in the same manner as with previous laboratory studies in mallards. In plasma, activities of total and Se-dependent glutathione peroxidase increased with time. As Se concentrations in liver increased, Se-dependent glutathione peroxidase, glutathione reductase, oxidized glutathione, and the ratio of hepatic oxidized to reduced glutathione increased. Total and protein bound sulfhydryl concentrations, reduced glutathione, glutathione-S-transferase, and glucose-6-phosphate dehydrogenase in liver were negatively correlated with Se concentrations in the liver. In Study 2, spleen weights were significantly lower in ducks receiving 60 ppm Se than in those receiving 20 ppm. Gross lesions associated with high Se exposure included emaciation, absence of thymus, loss of nails from digits, and alopecia. Microscopic lesions included severe depletion of lymphoid organs, hepatopathy, and necrosis of feather

  19. SHEDS-HT: an integrated probabilistic exposure model for prioritizing exposures to chemicals with near-field and dietary sources.

    PubMed

    Isaacs, Kristin K; Glen, W Graham; Egeghy, Peter; Goldsmith, Michael-Rock; Smith, Luther; Vallero, Daniel; Brooks, Raina; Grulke, Christopher M; Özkaynak, Halûk

    2014-11-04

    United States Environmental Protection Agency (USEPA) researchers are developing a strategy for high-throughput (HT) exposure-based prioritization of chemicals under the ExpoCast program. These novel modeling approaches for evaluating chemicals based on their potential for biologically relevant human exposures will inform toxicity testing and prioritization for chemical risk assessment. Based on probabilistic methods and algorithms developed for The Stochastic Human Exposure and Dose Simulation Model for Multimedia, Multipathway Chemicals (SHEDS-MM), a new mechanistic modeling approach has been developed to accommodate high-throughput (HT) assessment of exposure potential. In this SHEDS-HT model, the residential and dietary modules of SHEDS-MM have been operationally modified to reduce the user burden, input data demands, and run times of the higher-tier model, while maintaining critical features and inputs that influence exposure. The model has been implemented in R; the modeling framework links chemicals to consumer product categories or food groups (and thus exposure scenarios) to predict HT exposures and intake doses. Initially, SHEDS-HT has been applied to 2507 organic chemicals associated with consumer products and agricultural pesticides. These evaluations employ data from recent USEPA efforts to characterize usage (prevalence, frequency, and magnitude), chemical composition, and exposure scenarios for a wide range of consumer products. In modeling indirect exposures from near-field sources, SHEDS-HT employs a fugacity-based module to estimate concentrations in indoor environmental media. The concentration estimates, along with relevant exposure factors and human activity data, are then used by the model to rapidly generate probabilistic population distributions of near-field indirect exposures via dermal, nondietary ingestion, and inhalation pathways. Pathway-specific estimates of near-field direct exposures from consumer products are also modeled

  20. MEASURING EXCESS DIETARY EXPOSURES CAUSED BY EATING ACTIVITIES OF YOUNG CHILDREN

    EPA Science Inventory

    A small, pilot field study was conducted to measure dietary exposures of young children which included contamination of foods while eating. Samples were collected to estimate the amount of a pesticide recently applied within the home which was transferred from contaminated surfa...

  1. ESTIMATING CHILDREN'S DERMAL AND NON-DIETARY INGESTION EXPOSURE AND DOSE WITH EPA'S SHEDS MODEL

    EPA Science Inventory

    A physically-based stochastic model (SHEDS) has been developed to estimate pesticide exposure and dose to children via dermal residue contact and non-dietary ingestion. Time-location-activity data are sampled from national survey results to generate a population of simulated ch...

  2. MEASURING EXCESS DIETARY EXPOSURES CAUSED BY EATING ACTIVITIES OF YOUNG CHILDREN

    EPA Science Inventory

    A small, pilot field study was conducted to measure dietary exposures of young children which included contamination of foods while eating. Samples were collected to estimate the amount of a pesticide recently applied within the home which was transferred from contaminated surfa...

  3. ESTIMATING CHILDREN'S DERMAL AND NON-DIETARY INGESTION EXPOSURE AND DOSE WITH EPA'S SHEDS MODEL

    EPA Science Inventory

    A physically-based stochastic model (SHEDS) has been developed to estimate pesticide exposure and dose to children via dermal residue contact and non-dietary ingestion. Time-location-activity data are sampled from national survey results to generate a population of simulated ch...

  4. Evaluation of arsenic speciation in rainbow trout and fathead minnows from dietary exposure

    EPA Science Inventory

    The concentration of total arsenic and various arsenic species were measured in food and fish tissue samples from two dietary arsenic exposures to juvenile fish. For arsenic speciation, samples were extracted with 10% MeOH and analyzed by HPLC/ICPMS. Total arsenic concentration...

  5. Evaluation of arsenic speciation in rainbow trout and fathead minnows from dietary exposure

    EPA Science Inventory

    The concentration of total arsenic and various arsenic species were measured in food and fish tissue samples from two dietary arsenic exposures to juvenile fish. For arsenic speciation, samples were extracted with 10% MeOH and analyzed by HPLC/ICPMS. Total arsenic concentration...

  6. Dietary Nitrate Acutely and Markedly Increased Exhaled Nitric Oxide in a Cystic Fibrosis Case

    PubMed Central

    Kerley, Conor P.; Kilbride, Emma; Greally, Peter; Elnazir, Basil

    2016-01-01

    Airway nitric oxide (NO) is a ubiquitous signaling molecule with bronchoprotective, anti-inflammatory and anti-infective roles. Cystic fibrosis (CF) is a chronic lung condition associated with deceased exhaled NO. Strategies to increase exhaled NO in CF have yielded inconsistent results. A potential new method of increasing systemic NO involves ingestion of dietary, inorganic nitrate which is reduced to nitrite and NO. We present the case of a 12-year-old, athletic boy with CF who demonstrated acute but marked increases in exhaled NO following dietary nitrate consumption compared to placebo PMID:27630187

  7. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult rats were maintained on a chlorpyrifos-containing diet to p...

  8. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350g body weight by...

  9. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult rats were maintained on a chlorpyrifos-containing diet to p...

  10. NEUROBEHAVIORAL EFFECTS OF CHRONIC DIETARY AND REPEATED HIGH-LEVEL SPIKE EXPOSURE TO CHLORPYRIFOS IN RATS.

    EPA Science Inventory

    This study aimed to model long-term subtoxic human exposure to an organophosphorus pesticide, chlorpyrifos, and to examine the influence of that exposure on the response to intermittent high-dose acute challenges. Adult Long-Evans male rats were maintained at 350g body weight by...

  11. Medical mitigation strategies for acute radiation exposure during spaceflight.

    PubMed

    Epelman, Slava; Hamilton, Douglas R

    2006-02-01

    The United States Government has recently refocused their space program on manned missions to the Moon by 2018 and later to Mars. While there are many potential risks associated with exploration-class missions, one of the most serious and unpredictable is the effect of acute space radiation exposure, and the space program must make every reasonable effort to mitigate this risk. The two cosmic sources of radiation that could impact a mission outside the Earth's magnetic field are solar particle events (SPE) and galactic cosmic radiation (GCR). Either can cause acute and chronic medical illness. Numerous researchers are currently examining the ability of GCR exposure to induce the development of genetic changes that lead to malignancies and other delayed effects. However, relatively little has been published on the medical management of an acute SPE event and the potential impact on the mission and crew. This review paper will provide the readers with medical management options for an acute radiation event based on recommendations from the Department of Homeland Security (DHS), Centers for Disease Control (CDC), and evidence-based critical analysis of the scientific literature. It is the goal of this paper to stimulate debate regarding the definition of safety parameters for exploration-class missions to determine the level of medical care necessary to provide for the crew that will undertake such missions.

  12. Dietary exposure of Hong Kong secondary school students to total mercury and methylmercury from fish intake.

    PubMed

    Tang, Anna Shiu Ping; Kwong, Ka Ping; Chung, Stephen Wai Cheung; Ho, Yuk Yin; Xiao, Ying

    2009-01-01

    Fish is the main source of dietary exposure to methylmercury (MeHg), which is a public health concern owing to its potential neurotoxicity. To evaluate the public health risk, this study estimated the total mercury (tHg) and MeHg exposure from fish intake in Hong Kong secondary school students. Median tHg and MeHg concentrations of 280 samples purchased from different commercial outlets (covering 89 species of whole fish and three types of canned tuna), together with the local food consumption data of secondary school students obtained by semi-quantitative food frequency questionnaire in 2000, were used to estimate dietary exposure from fish intake for the average and high consumer (95th percentile exposure). For tHg, the median concentration was 63 µg kg(-1) (range 3-1370 µg kg(-1)) and estimated exposures ranged 0.5-0.6 µg kg(-1) body weight (bw) week(-1) for an average consumer and 1.6-1.9 µg kg(-1) bw week(-1) for a high consumer. For MeHg, median concentration was 48 µg kg(-1) (range 3-1010 µg kg(-1)) and estimated dietary exposures were 0.4-0.5 µg kg(-1) bw week(-1) for an average consumer and 1.2-1.4 µg kg(-1) bw week(-1) for a high consumer. These values are below the respective provisional tolerable weekly intake (PTWI) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA). The health risk is greater for high consumers since MeHg exposures may approach or exceed the PTWI when other dietary sources are taken into account.

  13. DIETARY EXPOSURE OF CHILDREN IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors; they have more opportunity for contact with lead sources due to their activities, lead absorption occurs more readily in a child compared to an adult, and the child's development i...

  14. DIETARY EXPOSURE OF CHILDREN LIVING IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors: they have more opportunity for contact with lead sources due to their activities; lead absorption occurs more readily in a child as compared to an adult; and the child's developmen...

  15. DIETARY EXPOSURE OF CHILDREN IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors; they have more opportunity for contact with lead sources due to their activities, lead absorption occurs more readily in a child compared to an adult, and the child's development i...

  16. DIETARY EXPOSURE OF CHILDREN LIVING IN LEAD-LADEN ENVIRONMENTS

    EPA Science Inventory

    Children are the most susceptible population to lead exposure because of three interacting factors: they have more opportunity for contact with lead sources due to their activities; lead absorption occurs more readily in a child as compared to an adult; and the child's developmen...

  17. Dietary exposure to aluminium from wheat flour and puffed products of residents in Shanghai, China.

    PubMed

    Guo, Junfei; Peng, Shaojie; Tian, Mingsheng; Wang, Liwei; Chen, Bo; Wu, Min; He, Gengsheng

    2015-01-01

    A dietary survey of 3431 residents was conducted by a 24-h dietary recall method in Shanghai, China, quarterly from September 2013 to September 2014. A total of 400 food samples were tested for aluminium concentration, including wheat flour and puffed products from 2011 to 2013. Probabilistic analysis was used to estimate the dietary exposure to aluminium from wheat and puffed products. The means of dietary aluminium exposure for children (2-6 years old), juveniles (7-17 years old), adults (18-65 years old) and seniors (over 65 years old) were 1.88, 0.94, 0.44 and 0.42 mg kg(-1) body weight (bw) week(-1) respectively, with a population average of 0.51 mg kg(-1) bw week(-1). The proportions of those who had aluminium exposure from wheat and puffed products lower than the provisional tolerable weekly intake (PTWI) were 77%, 90%, 97%, and 97% respectively from children to seniors. We estimated that the proportions of people at risk would decrease by 13%, 6%, 2% and 2% respectively under the new China National Standards - GB 2760-2014 National Food Safety for Standards for using food additives. The results indicated that aluminium from wheat flour and puffed products is unlikely to cause adverse health effects in the general population in Shanghai; however, children were at a higher risk of excess aluminium exposure. Significant improvements in reducing the dietary exposure to aluminium are expected in the population, especially for children after the implementation of GB 2760-2014.

  18. Assessing bisphenol A (BPA) exposure risk from long-term dietary intakes in Taiwan.

    PubMed

    Chen, Wei-Yu; Shen, Yi-Pei; Chen, Szu-Chieh

    2016-02-01

    Dietary intake is the major bisphenol A (BPA) exposure route in humans, and is a cause of BPA-related adverse effects. The large-scale exposure risk of humans to BPA through dietary sources in Taiwan is less well studied. The aim of this study was to assess the average daily dose (ADD) and hazardous quotient (HQ) of BPA exposure risk from long-term dietary intake of BPA, as well as BPA concentrations in different age-sex groups in Taiwan. We reanalyzed the BPA concentrations of regular daily food sources (rice, poultry, livestock, seafood, protein, fruits, and vegetables) and used a national dietary survey to estimate the contribution of variance to ADDs and potential human health effect for different age-sex groups. This study found that the daily consumption of chicken, pork/beef, and seafood were estimated to be 33.77 (Male)/22.65 (Female), 91.70 (M)/66.35 (F), and 54.15 (M)/40.78 (F) g/day, respectively. The highest BPA ADD was found in the 6-9 years age group (95% CI=0.0006-0.0027 mg/kg-bw/day), whereas the lowest BPA ADD was in the ≥65 years age group (0.0002-0.0020 mg/kg-bw/day). Based on the latest EFSA guidelines (0.004 mg/kg-bw/day), the 97.5 percentile HQ of BPA intake in different age-sex groups in Taiwan posed no risks through dietary intake. However, a combination of multiple exposure routes and long-term exposure in specific populations may be of concern in the future.

  19. Aluminum Exposure at Human Dietary Levels for 60 Days Reaches a Threshold Sufficient to Promote Memory Impairment in Rats.

    PubMed

    Martinez, Caroline S; Alterman, Caroline D C; Peçanha, Franck M; Vassallo, Dalton V; Mello-Carpes, Pâmela B; Miguel, Marta; Wiggers, Giulia A

    2017-01-01

    Aluminum (Al) is a significant environmental contaminant. While a good deal of research has been conducted on the acute neurotoxic effects of Al, little is known about the effects of longer-term exposure at human dietary Al levels. Therefore, the purpose of this study was to investigate the effects of 60-day Al exposure at low doses for comparison with a model of exposure known to produce neurotoxicity in rats. Three-month-old male Wistar rats were divided into two major groups: (1) low aluminum levels, and (2) a high aluminum level. Group 1 rats were treated orally by drinking water for 60 days as follows: (a) control-received ultrapure drinking water; (b) aluminum at 1.5 mg/kg b.w., and (c) aluminum at 8.3 mg/kg b.w. Group 2 rats were treated through oral gavages for 42 days as follows: (a) control-received ultrapure water; (b) aluminum at 100 mg/kg b.w. We analyzed cognitive parameters, biomarkers of oxidative stress and acetylcholinesterase (AChE) activity in hippocampus and prefrontal cortex. Al treatment even at low doses promoted recognition memory impairment seen in object recognition memory testing. Moreover, Al increased hippocampal reactive oxygen species and lipid peroxidation, reduced antioxidant capacity, and decreased AChE activity. Our data demonstrate that 60-day subchronic exposure to low doses of Al from feed and added to the water, which reflect human dietary Al intake, reaches a threshold sufficient to promote memory impairment and neurotoxicity. The elevation of oxidative stress and cholinergic dysfunction highlight pathways of toxic actions for this metal.

  20. Sensory and Cognitive Effects of Acute Exposure to Hydrogen Sulfide

    PubMed Central

    Fiedler, Nancy; Kipen, Howard; Ohman-Strickland, Pamela; Zhang, Junfeng; Weisel, Clifford; Laumbach, Robert; Kelly-McNeil, Kathie; Olejeme, Kelechi; Lioy, Paul

    2008-01-01

    Background Some epidemiologic studies have reported compromised cognitive and sensory performance among individuals exposed to low concentrations of hydrogen sulfide (H2S). Objectives We hypothesized a dose–response increase in symptom severity and reduction in sensory and cognitive performance in response to controlled H2S exposures. Methods In separate exposure sessions administered in random order over three consecutive weeks, 74 healthy subjects [35 females, 39 males; mean age (± SD) = 24.7 ± 4.2; mean years of education = 16.5 ± 2.4], were exposed to 0.05, 0.5, and 5 ppm H2S. During each exposure session, subjects completed ratings and tests before H2S exposure (baseline) and during the final hour of the 2-hr exposure period. Results Dose–response reduction in air quality and increases in ratings of odor intensity, irritation, and unpleasantness were observed. Total symptom severity was not significantly elevated across any exposure condition, but anxiety symptoms were significantly greater in the 5-ppm than in the 0.05-ppm condition. No dose–response effect was observed for sensory or cognitive measures. Verbal learning was compromised during each exposure condition. Conclusions Although some symptoms increased with exposure, the magnitude of these changes was relatively minor. Increased anxiety was significantly related to ratings of irritation due to odor. Whether the effect on verbal learning represents a threshold effect of H2S or an effect due to fatigue across exposure requires further investigation. These acute effects in a healthy sample cannot be directly generalized to communities where individuals have other health conditions and concomitant exposures. PMID:18197303

  1. Chronic nicotine exposure exacerbates acute renal ischemic injury

    PubMed Central

    Grifoni, Samira; Clark, Jeb S.; Csongradi, Eva; Maric, Christine; Juncos, Luis A.

    2011-01-01

    Recent epidemiological reports showed that smoking has a negative impact on renal function and elevates the renal risk not only in the renal patient but perhaps also in the healthy population. Studies suggested that nicotine, a major tobacco alkaloid, links smoking to renal dysfunction. While several studies showed that smoking/chronic nicotine exposure exacerbates the progression of chronic renal diseases, its impact on acute kidney injury is virtually unknown. Here, we studied the effects of chronic nicotine exposure on acute renal ischemic injury. We found that chronic nicotine exposure increased the extent of renal injury induced by warm ischemia-reperfusion as evidenced by morphological changes, increase in plasma creatinine level, and kidney injury molecule-1 expression. We also found that chronic nicotine exposure elevated markers of oxidative stress such as nitrotyrosine as well as malondialdehyde. Interestingly, chronic nicotine exposure alone increased oxidative stress and injury in the kidney without morphological alterations. Chronic nicotine treatment not only increased reactive oxygen species (ROS) production and injury but also exacerbated oxidative stress-induced ROS generation through NADPH oxidase and mitochondria in cultured renal proximal tubule cells. The resultant oxidative stress provoked injury through JNK-mediated activation of the activator protein (AP)-1 transcription factor in vitro. This mechanism might exist in vivo as phosphorylation of JNK and its downstream target c-jun, a component of the AP-1 transcription factor, is elevated in the ischemic kidneys exposed to chronic nicotine. Our results imply that smoking may sensitize the kidney to ischemic insults and perhaps facilitates progression of acute kidney injury to chronic kidney injury. PMID:21511693

  2. Chronic nicotine exposure exacerbates acute renal ischemic injury.

    PubMed

    Arany, Istvan; Grifoni, Samira; Clark, Jeb S; Csongradi, Eva; Maric, Christine; Juncos, Luis A

    2011-07-01

    Recent epidemiological reports showed that smoking has a negative impact on renal function and elevates the renal risk not only in the renal patient but perhaps also in the healthy population. Studies suggested that nicotine, a major tobacco alkaloid, links smoking to renal dysfunction. While several studies showed that smoking/chronic nicotine exposure exacerbates the progression of chronic renal diseases, its impact on acute kidney injury is virtually unknown. Here, we studied the effects of chronic nicotine exposure on acute renal ischemic injury. We found that chronic nicotine exposure increased the extent of renal injury induced by warm ischemia-reperfusion as evidenced by morphological changes, increase in plasma creatinine level, and kidney injury molecule-1 expression. We also found that chronic nicotine exposure elevated markers of oxidative stress such as nitrotyrosine as well as malondialdehyde. Interestingly, chronic nicotine exposure alone increased oxidative stress and injury in the kidney without morphological alterations. Chronic nicotine treatment not only increased reactive oxygen species (ROS) production and injury but also exacerbated oxidative stress-induced ROS generation through NADPH oxidase and mitochondria in cultured renal proximal tubule cells. The resultant oxidative stress provoked injury through JNK-mediated activation of the activator protein (AP)-1 transcription factor in vitro. This mechanism might exist in vivo as phosphorylation of JNK and its downstream target c-jun, a component of the AP-1 transcription factor, is elevated in the ischemic kidneys exposed to chronic nicotine. Our results imply that smoking may sensitize the kidney to ischemic insults and perhaps facilitates progression of acute kidney injury to chronic kidney injury.

  3. INSIGHT responsive parenting intervention is associated with healthier patterns of dietary exposures in infants.

    PubMed

    Hohman, Emily E; Paul, Ian M; Birch, Leann L; Savage, Jennifer S

    2017-01-01

    To determine whether a responsive parenting (RP) intervention affects infant dietary patterns. Primiparous mother-newborn dyads (n = 291) were randomized to the Intervention Nurses Start Infants Growing on Healthy Trajectories (INSIGHT) RP intervention or control. Curricula were delivered at nurse home visits at ages 3, 16, 28, and 40 weeks. RP group feeding guidance advised responsive feeding, delayed introduction of solids, repeated exposure to novel foods, and age-appropriate portion sizes. Latent class analysis identified patterns of dietary exposure at 9 months. Class membership at 9 months was used to predict BMI percentile at 2 years. Five dietary patterns were identified: "Breastfed, Fruits and Vegetables," "Breastfed, Low Variety," "Formula, Fruits and Vegetables," "Formula, Low Variety," and "Formula, High Energy Density." Over 60% of infants had patterns low in fruits and vegetables or high in energy-dense foods. RP group infants were less likely than control to be in the "Formula, Low Variety" class (OR = 0.40, 95% CI 0.23-0.71) or "Formula, High Energy Density" class (OR = 0.28, 95% CI 0.12-0.61) relative to the "Formula, Fruits and Vegetables" class. Dietary pattern at 9 months was significantly associated with BMI percentile at 2 years. While a majority of infants consumed diets low in fruits and vegetables, the INSIGHT RP intervention was associated with healthier dietary patterns. © 2016 The Obesity Society.

  4. Determination of caffeine and identification of undeclared substances in dietary supplements and caffeine dietary exposure assessment.

    PubMed

    Neves, Diana Brito da Justa; Caldas, Eloisa Dutra

    2017-07-01

    Caffeine is one of the most consumed stimulants in the world, and is a frequent ingredient of dietary supplements. The aims of this work were to validate a GC-MS method for the quantitation of caffeine and identification of other substances in supplements, mainly weight loss products, and to estimate the caffeine intake by consumers. Sample preparation included extraction with chloroform:water in ultrasonic bath, centrifugation and analysis of the organic layer for caffeine quantitation, and extraction with methanol for identification of other substances. A total of 213 samples of 52 supplement products not registered in Brazil and seized by the Brazilian Federal Police were analyzed. From the 109 samples that declared the amount of caffeine present, 26.6% contained more than 120% of the specified content. Considering the maximum recommended dose stated on the product labels, the consumption of 47.9% of the samples would lead to a daily intake of caffeine above the safe limit of 400 mg. Undeclared drugs, including sibutramine, phenolphthalein, amphepramone and femproporex were found in 28 samples. These results show that consumers of dietary supplements should be aware that these products might contain caffeine at levels that could represent potential health risks, in addition to undeclared pharmaceutical drugs. Copyright © 2017 Elsevier Ltd. All rights reserved.

  5. Dietary exposure to aflatoxins, ochratoxin A and deoxynivalenol from a total diet study in an adult urban Lebanese population.

    PubMed

    Raad, F; Nasreddine, L; Hilan, C; Bartosik, M; Parent-Massin, D

    2014-11-01

    Exposure to mycotoxins may be associated with carcinogenic, immunosuppressant and estrogenic effects. In the Middle-East, studies investigating food contamination and dietary exposure to mycotoxins are particularly scarce. This study aims at evaluating the dietary exposure of an adult Lebanese urban population to four mycotoxins (AFB1, AFM1, OTA, DON) classified as priority food contaminants by the WHO. Dietary exposure assessment was performed by means of the total diet study approach. Average and excessive consumer exposure estimates (p95) were calculated and compared with appropriate toxicological reference values (TRVs). Average dietary exposure levels to OTA and DON represented 29.9% and 156.8% of the respective TRVs, with the p95 exposure estimates approaching or exceeding the TRVs for these mycotoxins (95.1% and 355.8%, respectively). Based on the mean dietary exposure level to AFB1, cancer risk was estimated at 0.0527-0.0545cases/100,000persons/year, while mean exposure to AFM1 was associated with a population risk of 0.0018-0.0027cases/100,000persons/year. The study's findings place Lebanon among countries that are highly exposed to mycotoxins through the diet and call for larger-scale studies aiming at providing a comprehensive assessment of the dietary exposure of the Lebanese population to mycotoxins as well as to other food contaminants. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

  6. Evaluation onto life cycle parameters of Ceriodaphnia silvestrii submitted to 36 days dietary copper exposure.

    PubMed

    Rodgher, Suzelei; Lombardi, Ana Teresa; Gama Melão, Maria da Graça

    2009-09-01

    The present study aimed to investigate the response of several life history parameters (body length and age of primipara, duration of embryonic development, maximum body length, reproduction and survival) of the zooplankton Ceriodaphnia silvestrii while exposed to copper contaminated algae Pseudokirchneriella subcapitata. In order to evaluate chronic exposure on the animal's life history, long-term experimental design was used. Cladocerans were fed with a dietary copper concentration ranging from 3 to 68 fg Cu cell(-1). Low waterborne copper exposure (around 10(-10)molL(-1) free Cu(2+) ions) was kept in the experiments. The results showed that by exposure of cladocerans during 7 days to contaminated food with 68 fg Cu cell(-1), a significant reduction in neonate production, survival and body size were obtained. Inhibition on egg production of zooplankton at 38 fg Cu cell(-1) were observed in 36 days chronic dietary copper exposure. The importance of entire life cycle study to better evaluate cladoceran responses to chronic dietary metal exposure was demonstrated.

  7. Dietary exposure of the Italian population to inorganic arsenic: The 2012-2014 Total Diet Study.

    PubMed

    Cubadda, Francesco; D'Amato, Marilena; Aureli, Federica; Raggi, Andrea; Mantovani, Alberto

    2016-12-01

    Dietary exposure of the Italian population to inorganic arsenic has been assessed in the national Total Diet Study (TDS) carried out in 2012-2014. Within the TDS, food samples (>3000) were collected to be representative of the whole diet of the population, prepared as consumed, and pooled into 51 food groups, thus modelling the Italian diet. Inorganic arsenic was determined by HPLC-ICP-MS after chemical extraction and quantified in all samples. Occurrence data were combined with national individual consumption data to estimate mean and high level dietary exposure of the general population and of population subgroups according to age and gender, both at the national level and for each of the four main geographical areas of Italy. The intakes assessed are in the lower range of iAs exposure estimates in other European countries carried out without the support of the TDS approach. However, taking the lower limit of the BMDL01 range established by the EFSA as reference point, the margins of exposure are <2 for the mean intake in infants and toddlers and <1 for the 95th percentile intakes in all younger age groups. Our results indicate the goal to check and further reduce the dietary exposure to inorganic arsenic. Copyright © 2016 Elsevier Ltd. All rights reserved.

  8. Measured versus modeled dietary arsenic and relation to urinary arsenic excretion and total exposure

    PubMed Central

    Kurzius-Spencer, Margaret; O’Rourke, Mary Kay; Hsu, Chiu-Hsieh; Hartz, Vern; Harris, Robin B.; Burgess, Jefferey L.

    2014-01-01

    Chronic exposure to arsenic (As) in food and water is a significant public health problem. Person-specific aggregate exposure is difficult to collect, and modeling based on limited food As residue databases is of uncertain reliability. Two, cross-sectional, population exposure studies—the National Human Exposure Assessment Survey (NHEXAS)-Arizona and the Arizona Border Survey (ABS)— had a total of 252 subjects with diet, water, and urinary As data. Total As was measured in 24-hour duplicate diet samples and modeled using 24-hour diet diaries in conjunction with several published food surveys of As. Two-stage regression was used to assess the effects of dietary As on urinary total As (uAs): 1) generalized linear mixed models of uAs above versus below the limit of detection (LOD); and 2) restricted models limited to those subjects with uAs > LOD, using bootstrap sampling and mixed models adjusted for age, sex, BMI, ethnicity, current smoking, and As intake from drinking and cooking water. In restricted models, measured and modeled estimates were significant predictors of uAs. Modeled dietary As based on Total Diet Study mean residues greatly underestimated dietary intake. In households with tap water As ≤ 10 ppb, over 93% of total As exposure was attributable to diet. PMID:23321855

  9. Dietary exposure assessment of streptomycin and tetracycline in food of animal origin on the Croatian market.

    PubMed

    Vragović, Natalija; Bažulić, Davorin; Jakupović, Emira; Zdolec, Nevijo

    2012-01-01

    Residual antibacterials in food constitute a risk to human health, particularly because they can contribute to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. This paper presents dietary exposure assessment of streptomycin and tetracycline, based on combining food consumption data in Croatia with data on the concentration of veterinary drugs in analysed samples of food of animal origin. According to the median values, the estimated daily intake of streptomycin and tetracycline through food is 11.9 and 0.7 µg/person/day, respectively. The largest contribution to streptomycin intake comes from meat (4.8 µg/person/day, i.e. 41%), but milk is the largest source for tetracycline (0.3 µg/person/day, i.e. 46%). The estimated dietary exposure to these veterinary drugs does not exceed relevant toxicological reference values and the level of exposure is assessed to be acceptable.

  10. Dietary exposure assessment of Danish consumers to dithiocarbamate residues in food: a comparison of the deterministic and probabilistic approach.

    PubMed

    Jensen, B H; Andersen, J H; Petersen, A; Christensen, T

    2008-06-01

    Probabilistic and deterministic estimates of the acute and chronic exposure of the Danish populations to dithiocarbamate residues were performed. The Monte Carlo Risk Assessment programme (MCRA 4.0) was used for the probabilistic risk assessment. Food consumption data were obtained from the nationwide dietary survey conducted in 2000--02. Residue data for 5721 samples from the monitoring programme conducted in the period 1998--2003 were used for dithiocarbamates, which had been determined as carbon disulphide. Contributions from 26 commodities were included in the calculations. Using the probabilistic approach, the daily acute intakes at the 99.9% percentile for adults and children were 11.2 and 28.2 microg kg(-1) body weight day(-1), representing 5.6% and 14.1% of the ARfD for maneb, respectively. When comparing the point estimate approach with the probabilistic approach, the outcome of the point estimate calculations was generally higher or comparable with the outcome of the probabilistic approach at the 99.9 percentile (consumers only). The chronic exposures for adults and children were 0.35 and 0.76 microg kg(-1) body weight day(-1) at the 99.9 percentile, representing 0.7% and 1.5%, respectively, of the acceptable daily intake for mancozeb and maneb at 50 microg kg(-1) body weight.

  11. Consumption of fruits and vegetables and probabilistic assessment of the cumulative acute exposure to organophosphorus and carbamate pesticides of schoolchildren in Slovenia.

    PubMed

    Blaznik, Urška; Yngve, Agneta; Eržen, Ivan; Hlastan Ribič, Cirila

    2016-02-01

    Adequate consumption of fruits and vegetables is a part of recommendations for a healthy diet. The aim of the present study was to assess acute cumulative dietary exposure to organophosphorus and carbamate pesticides via fruit and vegetable consumption by the population of schoolchildren aged 11-12 years and the level of risk for their health. Cumulative probabilistic risk assessment methodology with the index compound approach was applied. Slovenia, primary schools. Schoolchildren (n 1145) from thirty-one primary schools in Slovenia. Children were part of the PRO GREENS study 2009/10 which assessed 11-year-olds' consumption of fruit and vegetables in ten European countries. The cumulative acute exposure amounted to 8.3 (95% CI 7.7, 10.6) % of the acute reference dose (ARfD) for acephate as index compound (100 µg/kg body weight per d) at the 99.9th percentile for daily intake and to 4.5 (95% CI 3.5, 4.7) % of the ARfD at the 99.9th percentile for intakes during school time and at lunch. Apples, bananas, oranges and lettuce contributed most to the total acute pesticides intake. The estimations showed that acute dietary exposure to organophosphorus and carbamate pesticides is not a health concern for schoolchildren with the assessed dietary patterns of fruit and vegetable consumption.

  12. Reduced foodborne toxin exposure is a benefit of improving dietary diversity.

    PubMed

    Wu, Felicia; Mitchell, Nicole J; Male, Denis; Kensler, Thomas W

    2014-10-01

    Naturally occurring foodborne toxins are common in subsistence diets of low-income human populations worldwide. Often, these populations rely on one or two staple foods for the bulk of their calories, making them more susceptible to chronic intake of certain toxins. Exposure to common foodborne toxins is associated with diverse conditions such as cancer, immunotoxicity, growth impairment, and neurological deficits. Interventions focused solely on reducing toxin levels have proven difficult to sustain. Using case studies of two foodborne toxins, aflatoxin and cassava cyanide, this article addresses the heightened risk of particular diseases from eating monotonous diets based in maize, groundnuts, and cassava: common in sub-Saharan Africa and parts of Asia. We also discuss the potential role of increased dietary diversity in counteracting these diseases. Increased dietary diversity can reduce consumption of toxins and increase intake of nutrients that could counteract the toxicity of such chemicals. In Qidong, China, a population that previously consumed a monotonous maize-based diet and increased dietary diversity since the 1980s has experienced a dramatic reduction in liver cancer mortalities. That liver cancer decreased as dietary diversity increased is the catalyst for the hypothesis that dietary diversity could have a direct impact on reducing health effects of foodborne toxins. Future research, agricultural development, and food policy reforms should take into consideration the multifaceted benefits associated with improved dietary diversity. Collaborations between toxicologists, nutritionists, and policymakers are important to development of sustainable interventions to reduce foodborne toxin exposure and promote health through increased dietary diversity. © The Author 2014. Published by Oxford University Press on behalf of the Society of Toxicology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  13. Dietary, food service, and mealtime interventions to promote food intake in acute care adult patients.

    PubMed

    Cheung, Grace; Pizzola, Lisa; Keller, Heather

    2013-01-01

    Malnutrition is common in acute care hospitals. During hospitalization, poor appetite, medical interventions, and food access issues can impair food intake leading to iatrogenic malnutrition. Nutritional support is a common intervention with demonstrated effectiveness. "Food first" approaches have also been developed and evaluated. This scoping review identified and summarized 35 studies (41 citations) that described and/or evaluated dietary, foodservice, or mealtime interventions with a food first focus. There were few randomized control trials. Individualized dietary treatment leads to improved food intake and other positive outcomes. Foodservices that promote point-of-care food selection are promising, but further research with food intake and nutritional outcomes is needed. Protected mealtimes have had insufficient implementation, leading to mixed results, while mealtime assistance, particularly provided by volunteers or dietary staff, appears to promote food intake. A few innovative strategies were identified but further research to develop and evaluate food first approaches is needed.

  14. Acute effects of cigarette smoke exposure on experimental skin flaps

    SciTech Connect

    Nolan, J.; Jenkins, R.A.; Kurihara, K.; Schultz, R.C.

    1985-04-01

    Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smoking in the perioperative period are suggested by this study.

  15. Does acute exposure to mobile phones affect human attention?

    PubMed

    Russo, Riccardo; Fox, Elaine; Cinel, Caterina; Boldini, Angela; Defeyter, Margaret A; Mirshekar-Syahkal, Dariush; Mehta, Amit

    2006-04-01

    Recent studies have indicated that acute exposure to low level radiofrequency (RF) electromagnetic fields generated by mobile phones affects human cognition. However, the relatively small samples used, in addition to methodological problems, make the outcomes of these studies difficult to interpret. In our study we tested a large sample of volunteers (168) using a series of cognitive tasks apparently sensitive to RF exposure (a simple reaction task, a vigilance task, and a subtraction task). Participants performed those tasks twice, in two different sessions. In one session they were exposed to RFs, with half of subjects exposed to GSM signals and the other half exposed to CW signals, while in the other session they were exposed to sham signals. No significant effects of RF exposure on performance for either GSM or CW were found, independent of whether the phone was positioned on the left or on the right side. (c) 2005 Wiley-Liss, Inc.

  16. Acute versus repeated chocolate exposure: effects on intake and cravings in restrained and unrestrained eaters.

    PubMed

    Coelho, Jennifer S; Nederkoorn, Chantal; Jansen, Anita

    2014-04-01

    The cue-reactivity model, which is based on conditioning processes, posits that repeated food exposure (in the absence of consumption) should decrease cue reactivity. To examine whether repeated chocolate exposure attenuates cravings and intake, relative to those exposed to an acute cue, a 2 (repeated vs acute cue) × 2 (restrained vs unrestrained eaters) design was employed. Fifty female participants were recruited. Repeated exposure reduced cravings in unrestrained eaters (relative to acute exposure), but increased cravings in restrained eaters. An interaction between restraint and exposure emerged on intake, such that restrained eaters ate less after acute exposure than did unrestrained eaters.

  17. Reducing prenatal phthalate exposure through maternal dietary changes: results from a pilot study

    PubMed Central

    Barrett, Emily S.; Velez, Marissa; Qiu, Xing; Chen, Shaw-Ree

    2016-01-01

    Objectives Diet is a major source of exposure to certain phthalates, a class of environmental chemicals associated with endocrine disruption in animal models and humans. Several studies have attempted to lower phthalate exposure through carefully designed dietary interventions, with inconsistent results. We conducted a dietary intervention pilot study with the objective to lower phthalate exposure in low-income pregnant women, a particularly vulnerable population. Methods Ten pregnant women consumed a provided diet consisting of mostly fresh, organic foods for three days. We collected urine samples before, during, and after the intervention and conducted semi-structured interviews to assess the feasibility and acceptability of the intervention. We used repeated measures ANOVA and paired t-tests to assess differences in urinary phthalate metabolite concentrations across the study, focusing on the metabolites of di-2-ethylhexyl phthalate (DEHP), a phthalate of particular interest, and their molar sum (∑DEHP). Results Phthalate metabolite concentrations did not change appreciably during the intervention period. We observed no significant difference in ∑DEHP metabolite concentrations across the three time periods (F=0.21; adjusted p-value=0.65), and no reduction during the intervention as compared to baseline (t=−1.07, adjusted p-value=0.51). Results of interviews indicated that participants were not motivated to make dietary changes to potentially reduce chemical exposures outside of the study. Conclusions Despite the small sample size, our results suggest that promoting dietary changes to lower phthalate exposure may not be an effective public health measure. Reducing the use of phthalates in food processing and packaging may be a better solution to lowering exposure on a population level. PMID:25652062

  18. Reducing Prenatal Phthalate Exposure Through Maternal Dietary Changes: Results from a Pilot Study.

    PubMed

    Barrett, Emily S; Velez, Marissa; Qiu, Xing; Chen, Shaw-Ree

    2015-09-01

    Diet is a major source of exposure to certain phthalates, a class of environmental chemicals associated with endocrine disruption in animal models and humans. Several studies have attempted to lower phthalate exposure through carefully designed dietary interventions, with inconsistent results. We conducted a dietary intervention pilot study with the objective to lower phthalate exposure in low-income pregnant women, a particularly vulnerable population. Ten pregnant women consumed a provided diet consisting of mostly fresh, organic foods for 3 days. We collected urine samples before, during, and after the intervention and conducted semi-structured interviews to assess the feasibility and acceptability of the intervention. We used repeated measures ANOVA and paired t-tests to assess differences in urinary phthalate metabolite concentrations across the study, focusing on the metabolites of di-2-ethylhexyl phthalate (DEHP), a phthalate of particular interest, and their molar sum (∑DEHP). Phthalate metabolite concentrations did not change appreciably during the intervention period. We observed no significant difference in ∑DEHP metabolite concentrations across the three time periods (F = 0.21; adjusted p value = 0.65), and no reduction during the intervention as compared to baseline (t = -1.07, adjusted p value = 0.51). Results of interviews indicated that participants were not motivated to make dietary changes to potentially reduce chemical exposures outside of the study. Despite the small sample size, our results suggest that promoting dietary changes to lower phthalate exposure may not be an effective public health measure. Reducing the use of phthalates in food processing and packaging may be a better solution to lowering exposure on a population level.

  19. Dietary patterns and their association with acute coronary heart disease: Lessons from the REGARDS Study

    PubMed Central

    Al Suwaidi, Jassim

    2015-01-01

    Shikany et al used data from 17,418 participants in the REGARDS study, a national, population-based, longitudinal study of white and black adults aged ≥ 45 years, enrolled between 2003–2007. They examined 536 acute coronary heart disease events at follow-up (median 5.8 years) in relation to five dietary patterns (Convenience, Plant-based, Sweets, Southern, and Alcohol and Salad). After adjustment for baseline variables, the highest consumers of the Southern pattern experienced a 56% higher hazard for acute CHD. PMID:26779528

  20. Short diet history for assessing dietary exposure to N-nitrosamines in epidemiologic studies

    SciTech Connect

    Howe, G.R.; Harrison, L.; Jain, M.

    1986-10-01

    A short diet history for use in assessing dietary nitrosamine exposure in epidemiologic studies has been developed by using data form a case-control study of diet and stomach cancer carried out in Ontario, Manitoba, and Newfoundland between 1979 and 1982. The method gives excellent correlations for seven dietary components with estimates based on a full diet history, and also performs well when tested on a different data set from a case-control study of diet and colorectal cancer carried out in Ontario and Alberta between 1976 and 1978.

  1. Prolonged prenatal psychotropic medication exposure alters neonatal acute pain response.

    PubMed

    Oberlander, Tim F; Eckstein Grunau, Ruth; Fitzgerald, Colleen; Ellwood, Ann-Louise; Misri, Shaila; Rurak, Dan; Riggs, Kenneth Wayne

    2002-04-01

    Selective serotonin reuptake inhibitors (SSRIs) and benzodiazepines are frequently used to treat maternal depression during pregnancy, however the effect of increased serotonin (5HT) and gamma-amino-butyric acid (GABA) agonists in the fetal human brain remains unknown. 5HT and GABA are active during fetal neurologic growth and play early roles in pain modulation, therefore, if prolonged prenatal exposure alters neurodevelopment this may become evident in altered neonatal pain responses. To examine biologic and behavioral effects of prenatal exposure, neonatal responses to acute pain (phenylketonuria heel lance) in infants with prolonged prenatal exposure were examined. Facial action (Neonatal Facial Coding System) and cardiac autonomic reactivity derived from the relationship between respiratory activity and short term variations of heart rate (HRV) were compared between 22 infants with SSRI exposure (SE) [fluoxetine (n = 7), paroxetine (n = 11), sertraline (n = 4)]; 16 infants exposed to SSRIs and clonazepam (SE+) [paroxetine (n = 14), fluoxetine (n = 2)]; and 23 nonexposed infants during baseline, lance, and recovery periods of a heel lance. Length of maternal SSRI use did not vary significantly between exposure groups-[mean (range)] SE:SE+ 183 (31-281):141 (54-282) d (p > 0.05). Infants exposed to SE and SE+ displayed significantly less facial activity to heel lance than control infants. Mean HR increased with lance, but was significantly lower in SE infants during recovery. Using measures of HRV and the transfer relationship between heart rate and respiration, SSRI infants had a greater return of parasympathetic cardiac modulation in the recovery period, whereas a sustained sympathetic response continued in the control group. Prolonged prenatal SSRI exposure appears to be associated with reduced behavioral pain responses and increased parasympathetic cardiac modulation in recovery following an acute neonatal noxious event. Possible 5HT-mediated pain inhibition

  2. Acute effects of dietary constituents on motor skill and cognitive performance in athletes.

    PubMed

    Baker, Lindsay B; Nuccio, Ryan P; Jeukendrup, Asker E

    2014-12-01

    Performance in many sports is at least partially dependent on motor control, coordination, decision-making, and other cognitive tasks. This review summarizes available evidence about the ingestion of selected nutrients or isolated compounds (dietary constituents) and potential acute effects on motor skill and/or cognitive performance in athletes. Dietary constituents discussed include branched-chain amino acids, caffeine, carbohydrate, cocoa flavanols, Gingko biloba, ginseng, guarana, Rhodiola rosea, sage, L-theanine, theobromine, and tyrosine. Although this is not an exhaustive list, these are perhaps the most researched dietary constituents. Caffeine and carbohydrate have the greatest number of published reports supporting their ability to enhance acute motor skill and cognitive performance in athletes. At this time, there is insufficient published evidence to substantiate the use of any other dietary constituents to benefit sports-related motor skill or cognitive performance. The optimal dose and timing of caffeine and carbohydrate intake promoting enhanced motor skill and cognitive performance remain to be identified. Valid, reliable, and sensitive batteries of motor skills and cognitive tests should be developed for use in future efficacy studies.

  3. Excretion Profiles and Half-Lives of Ten Urinary Polycyclic Aromatic Hydrocarbon Metabolites after Dietary Exposure

    PubMed Central

    Li, Zheng; Romanoff, Lovisa; Bartell, Scott; Pittman, Erin N.; Trinidad, Debra A.; McClean, Michael; Webster, Thomas F.; Sjödin, Andreas

    2015-01-01

    Human exposure to polycyclic aromatic hydrocarbons (PAHs) can be assessed by biomonitoring of their urinary mono-hydroxylated metabolites (OH-PAHs). Limited information exists on the human pharmacokinetics of OH-PAHs. This study aimed to investigate the excretion half-life of 1-hydroxypyrene (1-PYR), the most used biomarker for PAH exposure, and 9 other OH-PAHs following a dietary exposure in 9 non-smoking volunteers with no occupational exposure to PAHs. Each person avoided food with known high PAH-content during the study period, except for a high PAH-containing lunch (barbecued chicken) on the first day. Individual urine samples (n = 217) were collected from 15 hours before to 60 hours following the dietary exposure. Levels of all OH-PAHs in all subjects increased rapidly by 9–141 fold after the exposure, followed by a decrease consistent with first order kinetics, and returned to background levels 24–48 hours after the exposure. The average time to reach maximal concentration ranged from 3.1 h (1-naphthol) to 5.5 h (1-PYR). Creatinine-adjusted urine concentrations for each metabolite were analyzed using a non-linear mixed effects model including a term to estimate background exposure. The background-adjusted half-life estimate was 3.9 h for 1-PYR and ranged 2.5–6.1 h for the other 9 OH-PAHs, which in general, were shorter than those previously reported. The maximum concentrations after the barbecued chicken consumption were comparable to the levels found in reported occupational settings with known high PAH exposures. It is essential to consider the relatively short half-life, the timing of samples relative to exposures, and the effect of diet when conducting PAH exposure biomonitoring studies. PMID:22663094

  4. Dietary exposure to cadmium, lead and nickel among students from south-east Poland.

    PubMed

    Marzec, Zbigniew; Koch, Wojciech; Marzec, Agnieszka; Żukiewicz-Sobczak, Wioletta

    2014-01-01

    The dietary intake of cadmium, lead and nickel was determined among students from three universities in the city of Lublin in south-east Poland to assess the levels of exposure to these contaminants, compared to PTWI and TDI values. The study was performed in 2006–2010 and involved 850 daily food rations of students. The technique of 24-hour dietary recall and diet duplicates was used. Cadmium, lead and nickel complexes with ammonium-pyrrolidindithiocarbamate were formed and extracted to the organic phase with 4-methylpentan-2-one–MIBK, in which their content was measured by flame atomic absorption spectrometry. The highest intake of the elements studied was observed in 2008. The data show that in none of the cases, the level of intake reached 70% of PTWI/TDI values, and thus the risk of developing diseases related to high exposure to these toxic metals absorbed from foodstuffs was low. The parameters of methods were checked during determinations by adding standard solutions to the samples before mineralization and by using two reference materials: Total diet ARC/CL HDP and Bovine muscle RM NIST 8414. The dietary exposure to lead and cadmium has significantly decreased in recent years, whereas the exposures to nickel remains on a stable level.

  5. Dietary exposure to mycotoxins of the Hong Kong adult population from a Total Diet Study.

    PubMed

    Yau, Arthur Tin-Chung; Chen, Melva Yung-Yung; Lam, Chi-Ho; Ho, Yuk-Yin; Xiao, Ying; Chung, Stephen Wai-Cheung

    2016-06-01

    Dietary exposure of Hong Kong adults to mycotoxins and their metabolites including aflatoxins (AFs), ochratoxin A (OTA), fumonisins (FNs), deoxynivalenol (DON), acetyldeoxynivalenols (AcDONs) and zearalenone (ZEA) was estimated using the Total Diet Study (TDS) approach to assess the associated health risk to the local people. Sixty commonly consumed food items, collected in four seasons, were sampled and prepared as consumed. These mycotoxins were primarily found at low levels. The highest mean levels (upper bound) were: AFs, 1.50 µg kg(-)(1) in legumes, nuts and seed; OTA, 0.22 µg kg(-)(1) in sugars and confectionery; FNs, 9.76 µg kg(-)(1) in cereals and their products; DON and AcDONs, 33.1 µg kg(-)(1) in cereals and their products; and ZEA, 53.8 µg kg(-)(1) in fats and oils. The estimated dietary exposures of Hong Kong adults to the mycotoxins analysed were well below the respective health-based guidance values, where available. For AFs, the upper-bound exposure for high consumers is 0.0049 µg kg bw(-)(1) day(-)(1), which was estimated to contribute to about 7.7 (< 1%) of liver cancer cases when compared with 1222 liver cancer cases per year in Hong Kong. The percentage contributions of the estimated 95th percentile dietary exposures (lower and upper bound) to the health-based guidance values of individual mycotoxins were: ochratoxin A, 3.6-9.2%; fumonisins, 0.04-8.5%; deoxynivalenol and acetyldeoxynivalenols, 21.7-28.2%; and zearalenone 3.3-34.5%. The findings indicate that dietary exposures to all the mycotoxins analysed in this study were unlikely to pose an unacceptable health risk to the Hong Kong population.

  6. Human Physiological Responses to Acute and Chronic Cold Exposure

    NASA Technical Reports Server (NTRS)

    Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

    2001-01-01

    When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

  7. Human Physiological Responses to Acute and Chronic Cold Exposure

    NASA Technical Reports Server (NTRS)

    Stocks, Jodie M.; Taylor, Nigel A. S.; Tipton, Michael J.; Greenleaf, John E.

    2001-01-01

    When inadequately protected humans are exposed to acute cold, excessive body heat is lost to the environment and unless heat production is increased and heat loss attenuated, body temperature will decrease. The primary physiological responses to counter the reduction in body temperature include marked cutaneous vasoconstriction and increased metabolism. These responses, and the hazards associated with such exposure, are mediated by a number of factors which contribute to heat production and loss. These include the severity and duration of the cold stimulus; exercise intensity; the magnitude of the metabolic response; and individual characteristics such as body composition, age, and gender. Chronic exposure to a cold environment, both natural and artificial, results in physiological alterations leading to adaptation. Three quite different, but not necessarily exclusive, patterns of human cold adaptation have been reported: metabolic, hypothermic, and insulative. Cold adaptation has also been associated with an habituation response, in which there is a desensitization, or damping, of the normal response to a cold stress. This review provides a comprehensive analysis of the human physiological and pathological responses to cold exposure. Particular attention is directed to the factors contributing to heat production and heat loss during acute cold stress, and the ability of humans to adapt to cold environments.

  8. Endocrine responses in the rhesus monkey during acute cold exposure

    SciTech Connect

    Lotz, W.G.; Saxton, J.L. )

    1991-03-11

    The authors studied five young male rhesus monkeys (Macaca mulatta), 3.4 to 6.7 kg, to determine the relationship between fluid balance hormones and urine production during acute, dry cold exposure. Each monkey served as its own control in duplicate experimental sessions at 6C or 26C. A 6-h experimental session consisted of 120 min equilibration at 26C, 120 min experimental exposure, and 120 min recovery at 26C. Urinary and venous catheters were inserted on the morning of a session. Rectal (Tre) and skin temperatures were monitored continuously. Blood samples were taken at 0, 30, 60 and 120 min of exposure, and at 60 min postexposure. Plasma was analyzed for arginine vasopressin (AVP), atrial natriuretic factor (ANF), plasma renin activity (PRA), plasma aldosterone (PA), and osmolality. Urine samples were analyzed for osmolality, electrolytes, and creatinine. Mean Tre was 1.6C lower after 120 min at 6C than at 26C. Urine volume and osmolality were not altered by cold exposure, as they are in humans and rats. Vasopressin and PA increased sharply, with mean plasma levels in monkeys exposed to cold more than threefold and tenfold, respectively, the levels in monkeys exposed at 26C. In contrast, ANF, PRA, and plasma osmolality were not significantly changed by cold exposure. The absence of a cold-induced diuresis in the monkey may be related to the marked increase in plasma AVP level.

  9. [Dietary exposure assessment of some important Fusarium toxins in cereal-based products in China].

    PubMed

    Wang, Wei; Shao, Bing; Zhu, Jianghui; Yu, Hongxia; Li, Fengqin

    2010-11-01

    To elucidate the dietary exposure of Chinese populations to deoxynivalenol (DON), nivalenol (NIV) and zearalenone (ZEN). Ten Fusarium toxins including DON, NIV, ZEN in domestic wheat flour and corn-based products harvested and collected in 2009 were analyzed by UPLC-MS/MS. Dietary intake assessments of human exposure to DON, NIV and ZEN were carried out in combination of national food consumption data with toxin concentration data by deterministic estimate method. (1) There are 2.5% adults and 10% children with the dietary exposure to DON exceeding the tolerable daily intake (TDI) on the basis of the average food consumption. At the 75th percentile food consumption level, the dietary exposure of populations to DON was higher than its TDI, 1.72 and 2.02 times (adults) as well as 1.19 and 1.09 times higher than TDI (children), respectively, based on the higher DON exposure (adults : P90 for wheat flour and P97. 5 for corn-based products, children: P50 for wheat flour and P75 for corn-based products). At the average toxin concentration, children with the high consumption level (90th, 97. 5th and 99th percentile) of either wheat flour or corn-based products, the dietary exposure to DON exceed the TDI, 1.81 to 3.17 times (wheat flour) and 1.47 - 3.97 times (corn-based products) higher than TDI, respectively. The dietary exposure of adults to ZEN exceed the TDI, based on the average food consumption data and higher ZEN level (P99), the 75th consumption data combined with P97. 5th toxin concentration, as well as 90th percentile of both food consumption data and ZEN concentration, respectively. There are 1%, 2.5%, 25%, 25% and 50% populations of children exposed ZEN higher than TDI, respectively at the 50th, 75th, 90th, 97. 5th and 99th percentile of food consumption data. (2) The level of concern (LOC) of DON in wheat flour calculated with high consumption data (90th, 97. 5th and 99th percentile) for all populations as well as DON and ZEN in corn-based products calculated

  10. Prolonged exposure to high dietary lipids is not associated with lipotoxicity in heart failure.

    PubMed

    Rennison, Julie H; McElfresh, Tracy A; Chen, Xiaoqin; Anand, Vijay R; Hoit, Brian D; Hoppel, Charles L; Chandler, Margaret P

    2009-06-01

    Previous studies have reported that elevated myocardial lipids in a model of mild-to-moderate heart failure increased mitochondrial function, but did not alter left ventricular function. Whether more prolonged exposure to high dietary lipids would promote a lipotoxic phenotype in mitochondrial and myocardial contractile function has not been determined. We tested the hypothesis that prolonged exposure to high dietary lipids, following coronary artery ligation, would preserve myocardial and mitochondrial function in heart failure. Rats underwent ligation or sham surgery and were fed normal (10% kcal fat) (SHAM, HF) or high fat diet (60% kcal saturated fat) (SHAM+FAT, HF+FAT) for sixteen weeks. Although high dietary fat was accompanied by myocardial tissue triglyceride accumulation (SHAM 1.47+/-0.14; SHAM+FAT 2.32+/-0.14; HF 1.34+/-0.14; HF+FAT 2.21+/-0.20 micromol/gww), fractional shortening was increased 16% in SHAM+FAT and 28% in HF+FAT compared to SHAM and HF, respectively. Despite increased medium-chain acyl-CoA dehydrogenase (MCAD) activity in interfibrillar mitochondria (IFM) of both SHAM+FAT and HF+FAT, dietary lipids also were associated with decreased state 3 respiration using palmitoylcarnitine (SHAM 369+/-14; SHAM+FAT 307+/-23; HF 354+/-13; HF+FAT 366+/-18 nAO min(-1) mg(-1)) in SHAM+FAT compared to SHAM and HF+FAT. State 3 respiration in IFM also was decreased in SHAM+FAT relative to SHAM using succinate and DHQ. In conclusion, high dietary lipids promoted myocardial lipid accumulation, but were not accompanied by alterations in myocardial contractile function typically associated with lipotoxicity. In normal animals, high dietary fat decreased mitochondrial respiration, but also increased MCAD activity. These studies support the concept that high fat feeding can modify multiple cellular pathways that differentially affect mitochondrial function under normal and pathological conditions.

  11. Dietary exposure biomarker-lead discovery based on metabolomics analysis of urine samples.

    PubMed

    Beckmann, Manfred; Lloyd, Amanda J; Haldar, Sumanto; Favé, Gaëlle; Seal, Chris J; Brandt, Kirsten; Mathers, John C; Draper, John

    2013-08-01

    Although robust associations between dietary intake and population health are evident from conventional observational epidemiology, the outcomes of large-scale intervention studies testing the causality of those links have often proved inconclusive or have failed to demonstrate causality. This apparent conflict may be due to the well-recognised difficulty in measuring habitual food intake which may lead to confounding in observational epidemiology. Urine biomarkers indicative of exposure to specific foods offer information supplementary to the reliance on dietary intake self-assessment tools, such as FFQ, which are subject to individual bias. Biomarker discovery strategies using non-targeted metabolomics have been used recently to analyse urine from either short-term food intervention studies or from cohort studies in which participants consumed a freely-chosen diet. In the latter, the analysis of diet diary or FFQ information allowed classification of individuals in terms of the frequency of consumption of specific diet constituents. We review these approaches for biomarker discovery and illustrate both with particular reference to two studies carried out by the authors using approaches combining metabolite fingerprinting by MS with supervised multivariate data analysis. In both approaches, urine signals responsible for distinguishing between specific foods were identified and could be related to the chemical composition of the original foods. When using dietary data, both food distinctiveness and consumption frequency influenced whether differential dietary exposure could be discriminated adequately. We conclude that metabolomics methods for fingerprinting or profiling of overnight void urine, in particular, provide a robust strategy for dietary exposure biomarker-lead discovery.

  12. Dietary supplementation and rapid catch-up growth after acute diarrhoea in childhood.

    PubMed

    Hoare, S; Poppitt, S D; Prentice, A M; Weaver, L T

    1996-10-01

    Diarrhoea is a major cause of short-term growth faltering in children of the developing world. If catch-up weight gain is delayed by inadequate dietary intake, or by further bouts of diarrhoea, progressive growth failure occurs. To test the hypothesis that early refeeding is as effective as later feeding after acute diarrhoea with weight loss, we measured the effects of a timed dietary intervention on weight gain after acute diarrhoea in underweight Gambian children. Thirty-four children aged 4-22 months with weight loss following acute diarrhoea were given a high-energy-protein supplement for 14 d beginning either immediately after rehydration or a fortnight later. With a 50% increase in energy intake and a 100% increase in protein intake there was a rapid and highly significant (P < 0.001) gain in weight within a fortnight whether the supplement was given immediately or 2 weeks after presentation. Rates of weight increase were similar whether supplementation was provided early or late, but over the full 28 d (of intervention and non-intervention) children who received late supplementation had greater overall weight gain (P < 0.02) than those supplemented early. Vigorous and early feeding with a high-energy-protein supplement should be central to the management of malnourished children with acute diarrhoea in developing countries, and may be as important as control of diarrhoea in preventing malnutrition and growth failure. This may be achieved in the community using locally available foods, in the face of continuing diarrhoea.

  13. Mitigation Strategies for Acute Radiation Exposure during Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Epelman, Slava

    2006-01-01

    While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 grams per square centimeters would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

  14. Mitigation Strategies for Acute Radiation Exposure during Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Epelman, Slava

    2006-01-01

    While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low-dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 gm/cm(sup 2) would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

  15. Mitigation Strategies for Acute Radiation Exposure during Space Flight

    NASA Technical Reports Server (NTRS)

    Hamilton, Douglas R.; Epelman, Slava

    2006-01-01

    While there are many potential risks in a Moon or Mars mission, one of the most important and unpredictable is that of crew radiation exposure. The two forms of radiation that impact a mission far from the protective environment of low-earth orbit, are solar particle events (SPE) and galactic cosmic radiation (GCR). The effects of GCR occur as a long-term cumulative dose that results increased longer-term medical risks such as malignancy and neurological degeneration. Unfortunately, relatively little has been published on the medical management of an acute SPE that could potentially endanger the mission and harm the crew. Reanalysis of the largest SPE in August 1972 revealed that the dose rate was significantly higher than previously stated in the literature. The peak dose rate was 9 cGy h(sup -1) which exceeds the low-dose-rate criteria for 25 hrs (National Council on Radiation Protection) and 16 hrs (United Nations Scientific Committee on the Effects of Atomic Radiation). The bone marrow dose accumulated was 0.8 Gy, which exceeded the 25 and 16 hour criteria and would pose a serious medical risk. Current spacesuits would not provide shielding from the damaging effects for an SPE as large as the 1972 event, as increased shielding from 1-5 gm/cm(sup 2) would do little to shield the bone marrow from exposure. Medical management options for an acute radiation event are discussed based on recommendations from the Department of Homeland Security, Centers for Disease Control and evidence-based scientific literature. The discussion will also consider how to define acute exposure radiation safety limits with respect to exploration-class missions, and to determine the level of care necessary for a crew that may be exposed to an SPE similar to August 1972.

  16. Acute radiation syndrome caused by accidental radiation exposure - therapeutic principles.

    PubMed

    Dörr, Harald; Meineke, Viktor

    2011-11-25

    Fortunately radiation accidents are infrequent occurrences, but since they have the potential of large scale events like the nuclear accidents of Chernobyl and Fukushima, preparatory planning of the medical management of radiation accident victims is very important. Radiation accidents can result in different types of radiation exposure for which the diagnostic and therapeutic measures, as well as the outcomes, differ. The clinical course of acute radiation syndrome depends on the absorbed radiation dose and its distribution. Multi-organ-involvement and multi-organ-failure need be taken into account. The most vulnerable organ system to radiation exposure is the hematopoietic system. In addition to hematopoietic syndrome, radiation induced damage to the skin plays an important role in diagnostics and the treatment of radiation accident victims. The most important therapeutic principles with special reference to hematopoietic syndrome and cutaneous radiation syndrome are reviewed.

  17. Psychological symptoms and intermittent hypertension following acute microwave exposure

    SciTech Connect

    Forman, S.A.; Holmes, C.K.; McManamon, T.V.; Wedding, W.R.

    1982-11-01

    Two men who were accidently, acutely irradiated with X-band microwave radiation have been followed up clinically for 12 months. Both men developed similar psychological symptoms, which included emotional lability, irritability, headaches, and insomnia. Several months after the incidents, hypertension was diagnosed in both patients. No organic basis for the psychological problems could be found nor could any secondary cause for the hypertension. A similar syndrome following microwave exposure has been described by the East Europeans. The two cases we report, with comparable subjective symptoms and hypertension following a common exposure, provide further strong, circumstantial evidence of cause and effect. A greater knowledge of the mechanisms involved in bioeffects which may be induced by radiofrequency and microwave radiation is definitely needed.

  18. Dietary exposure to persistent organochlorine pesticides in 2007 Chinese total diet study.

    PubMed

    Zhou, Pingping; Zhao, Yunfeng; Li, Jingguang; Wu, Guohua; Zhang, Lei; Liu, Qing; Fan, Sai; Yang, Xin; Li, Xiaowei; Wu, Yongning

    2012-07-01

    Dietary exposure to persistent organochlorine pesticides (OCPs) was assessed for Chinese populations, using the total diet study (TDS) approach in 2007. Multistage random cluster sampling method was used in this study. 108 composite samples, representative of foods "as consumed" by the Chinese were analyzed for residues of OCPs by a multi-residue method. The result showed that hexachlorobenzene (HCB), dichloro-diphenyl-trichloroethane (DDT), chlordane compounds (CHLs), hexachlorocyclohexane (HCH) and heptachlor could be detected in, respectively 84%, 39%, 37%, 13% and 5% of all samples. Concentrations of DDT in all samples ranged from undetectable levels to 72.2 μg/kg. Others were minor components in the OCPs profile. The residual levels of OCPs were significantly below the Extraneous Maximum Residue Limits (EMRLs). Based on the 2000 nationwide food consumption survey, the average dietary exposure of the Chinese to DDT, HCH, HCB, CHLs, and heptachlor was estimated to be 0.016, 0.002, 0.009, 0.006, and 0.001 μg/kg body weight per day respectively, showing a significant decrease trend compared with the past. The major food groups contributing to dietary OCPs were aquatic foods, meats, and cereals. The average and high end estimated daily intakes of different OCPs for the Chinese were both lower than the tolerable daily intake (TDI) suggested by authorities indicating low health risk of OCPs dietary exposure among Chinese adults at present. However, the risk of carcinogenicity of the OCPs should be concerned with if the carcinogenicity effects from the exposures to these OCPs were considered. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Dietary exposure to polychlorinated biphenyls is associated with increased risk of stroke in women.

    PubMed

    Bergkvist, C; Kippler, M; Larsson, S C; Berglund, M; Glynn, A; Wolk, A; Åkesson, A

    2014-09-01

    The potentially beneficial effects of fish consumption on stroke may be modified by major food contaminants in fish. Polychlorinated biphenyls (PCBs) in particular are proposed to play a role in the aetiology of stroke. The aim of this study was to assess the association between dietary PCB exposure and stroke risk with the intake of long-chain omega-3 fish fatty acids and fish consumption. The prospective population-based Swedish Mammography Cohort was examined. It was comprised of 34,591 women free of cardiovascular diseases and cancer at baseline in 1997 and followed up for 12 years. Validated estimates of dietary PCB exposure were obtained via a food frequency questionnaire at baseline. Incident cases of stroke were ascertained through register linkage. During 12 years of follow-up (397,309 person-years), there were 2015 incident cases of total stroke (1532 ischaemic strokes, 216 intracerebral haemorrhages, 94 subarachnoid haemorrhages and 173 unspecified strokes). Multivariable-adjusted relative risks (RR), controlled for known stroke risk factors and fish consumption, were 1.67 [95% confidence interval (CI), 1.29-2.17] for total stroke, 1.61 (95% CI, 1.19-2.17) for ischaemic stroke and 2.80 (95% CI, 1.42-5.55) for haemorrhagic stroke for women in the highest quartile of dietary PCB exposure (median 288 ng day(-1) ) compared with women in the lowest quartile (median 101 ng day(-1) ). Dietary exposure to PCBs was associated with an increased stroke risk in women, especially haemorrhagic stroke. The results provide important information regarding the risk-benefit analysis of fish consumption, particularly for cerebrovascular disease prevention. © 2014 The Association for the Publication of the Journal of Internal Medicine.

  20. Dietary cadmium exposure and prostate cancer incidence: a population-based prospective cohort study

    PubMed Central

    Julin, B; Wolk, A; Johansson, J-E; Andersson, S-O; Andrén, O; Åkesson, A

    2012-01-01

    Background: Experimental data convincingly propose the toxic metal cadmium as a prostate carcinogen. Cadmium is widely dispersed into the environment and, consequently, food is contaminated. Methods: A population-based cohort of 41 089 Swedish men aged 45–79 years was followed prospectively from 1998 through 2009 to assess the association between food frequency questionnaire-based estimates of dietary cadmium exposure (at baseline, 1998) and incidence of prostate cancer (3085 cases, of which 894 were localised and 794 advanced) and through 2008 for prostate cancer mortality (326 fatal cases). Results: Mean dietary cadmium exposure was 19 μg per day±s.d. 3.7. Multivariable-adjusted dietary cadmium exposure was positively associated with overall prostate cancer, comparing extreme tertiles; rate ratio (RR) 1.13 (95% confidence interval (CI): 1.03–1.24). For subtypes of prostate cancer, the RR was 1.29 (95% CI: 1.08–1.53) for localised, 1.05 (95% CI: 0.87–1.25) for advanced, and 1.14 (95% CI: 0.86–1.51) for fatal cases. No statistically significant difference was observed in the multivariable-adjusted risk estimates between tumour subtypes (Pheterogeneity=0.27). For localised prostate cancer, RR was 1.55 (1.16–2.08) among men with a small waist circumference and RR 1.45 (1.15, 1.83) among ever smokers. Conclusion: Our findings provide support that dietary cadmium exposure may have a role in prostate cancer development. PMID:22850555

  1. Chronic exposure to dietary selenomethionine increases gonadal steroidogenesis in female rainbow trout.

    PubMed

    Wiseman, Steve; Thomas, Jith K; Higley, Eric; Hursky, Olesya; Pietrock, Michael; Raine, Jason C; Giesy, John P; Janz, David M; Hecker, Markus

    2011-10-01

    Selenomethionine (Se-Met) is the major dietary form of selenium (Se). Detrimental effects have been associated with exposure to elevated dietary selenium. Previous studies have demonstrated effects of Se on the endocrine system, in particular effects on cortisol and thyroid hormones. However, no information is available regarding effects of Se on sex steroid hormones. In the present study, effects of dietary exposure to an environmentally relevant concentration (4.54 mg/kg wet weight (ww)) of Se-Met for 126 days on concentrations of sex steroid hormones in blood plasma of female rainbow trout were determined. Furthermore, the molecular basis for effects of Se-Met on plasma sex steroid hormone concentrations was investigated. Concentrations of androstenedione (A), estrone (E1), and estradiol (E2) were 39.5-, 3.8-, and 12.7-fold greater in plasma of treated females than the untreated controls, respectively. Testosterone (T) was detected only in plasma of treated females. The greater E2 concentration stimulated greater transcript abundance of vitellogenin (vtg) and zona-radiata protein (zrp). Female rainbow trout exposed to Se-Met had greater transcript abundance of key steroidogenic proteins and enzymes, including peripheral benzodiazepine receptor (pbr), cytochrome P450 side-chain cleavage (P450scc), and 3β-hydroxysteroid dehydrogenase (3β-hsd). Exposure to Se-Met did not affect transcript abundance of luteinizing hormone (lh) or follicle stimulating hormone (fsh). Similarly, there was no change in transcript abundance of luteinizing hormone receptor (lhr) or follicle stimulating hormone receptor (fshr). Long-term exposure to dietary Se-Met has the potential to stimulate vitellogenesis in female rainbow trout by directly stimulating ovarian tissue steroidogenesis. This is the first study to report effects of Se on sex steroid hormone production in fish. Copyright © 2011 Elsevier B.V. All rights reserved.

  2. Dietary exposure assessments for children in europe (the EXPOCHI project): rationale, methods and design

    PubMed Central

    2011-01-01

    Background/purpose The number of dietary exposure assessment studies focussing on children is very limited. Children are however a vulnerable group due to their higher food consumption level per kg body weight. Therefore, the EXPOCHI project aims [1] to create a relational network of individual food consumption databases in children, covering different geographical areas within Europe, and [2] to use these data to assess the usual intake of lead, chromium, selenium and food colours. Methods EXPOCHI includes 14 food consumption databases focussed on children (1-14 y old). The data are considered representative at national/regional level: 14 regions covering 13 countries. Since the aim of the study is to perform long-term exposure assessments, only data derived from 24 hr dietary recalls and dietary records recorded on at least two non-consecutive days per individual were included in the dietary exposure assessments. To link consumption data and concentration data of lead, chromium and selenium in a standardised way, categorisation of the food consumption data was based on the food categorisation system described within the SCOOP Task report 3.2.11. For food colours, the food categorisation system specified in the Council Directive 94/36/EC was used. Conclusion The EXPOCHI project includes a pan-European long-term exposure assessment of lead, chromium, selenium and food colours among children living in 13 different EU countries. However, the different study methods and designs used to collect the data in the different countries necessitate an in-depth description of these different methods and a discussion about the resulting limitations. PMID:22958503

  3. Estimating Pesticide Exposure from Dietary Intake and Organic Food Choices: The Multi-Ethnic Study of Atherosclerosis (MESA)

    PubMed Central

    Beresford, Shirley A.A.; Fenske, Richard A.; Fitzpatrick, Annette L.; Lu, Chensheng; Nettleton, Jennifer A.; Kaufman, Joel D.

    2015-01-01

    Background Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. Objectives We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Methods Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce (“conventional consumers”), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Results Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p < 0.05). DAP concentrations were also significantly lower in groups reporting more frequent consumption of organic produce (p < 0.02). Conclusions Long-term dietary exposure to OPs was estimated from dietary intake data, and estimates were consistent with DAP measurements. More frequent consumption of organic produce was associated with lower DAPs. Citation Curl CL, Beresford SA, Fenske RA, Fitzpatrick AL, Lu C, Nettleton JA, Kaufman JD. 2015. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA). Environ

  4. Responses of Hyalella azteca to acute and chronic microplastic exposures.

    PubMed

    Au, Sarah Y; Bruce, Terri F; Bridges, William C; Klaine, Stephen J

    2015-11-01

    Limited information is available on the presence of microplastics in freshwater systems, and even less is known about the toxicological implications of the exposure of aquatic organisms to plastic particles. The present study was conducted to evaluate the effects of microplastic ingestion on the freshwater amphipod, Hyalella azteca. Hyalella azteca was exposed to fluorescent polyethylene microplastic particles and polypropylene microplastic fibers in individual 250-mL chambers to determine 10-d mortality. In acute bioassays, polypropylene microplastic fibers were significantly more toxic than polyethylene microplastic particles; 10-d lethal concentration 50% values for polyethylene microplastic particles and polypropylene microplastic fibers were 4.64 × 10(4) microplastics/mL and 71.43 microplastics/mL, respectively. A 42-d chronic bioassay using polyethylene microplastic particles was conducted to quantify effects on reproduction, growth, and egestion. Chronic exposure to polyethylene microplastic particles significantly decreased growth and reproduction at the low and intermediate exposure concentrations. During acute exposures to polyethylene microplastic particles, the egestion times did not significantly differ from the egestion of normal food materials in the control; egestion times for polypropylene microplastic fibers were significantly slower than the egestion of food materials in the control. Amphipods exposed to polypropylene microplastic fibers also had significantly less growth. The greater toxicity of microplastic fibers than microplastic particles corresponded with longer residence times for the fibers in the gut. The difference in residence time might have affected the ability to process food, resulting in an energetic effect reflected in sublethal endpoints. © 2015 SETAC.

  5. Histopathologic Alterations Associated with Global Gene Expression Due to Chronic Dietary TCDD Exposure in Juvenile Zebrafish

    PubMed Central

    Liu, Qing; Spitsbergen, Jan M.; Cariou, Ronan; Huang, Chun-Yuan; Jiang, Nan; Goetz, Giles; Hutz, Reinhold J.; Tonellato, Peter J.; Carvan, Michael J.

    2014-01-01

    The goal of this project was to investigate the effects and possible developmental disease implication of chronic dietary TCDD exposure on global gene expression anchored to histopathologic analysis in juvenile zebrafish by functional genomic, histopathologic and analytic chemistry methods. Specifically, juvenile zebrafish were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb, and fish were sampled following 0, 7, 14, 28 and 42 d after initiation of the exposure. TCDD accumulated in a dose- and time-dependent manner and 100 ppb TCDD caused TCDD accumulation in female (15.49 ppb) and male (18.04 ppb) fish at 28 d post exposure. Dietary TCDD caused multiple lesions in liver, kidney, intestine and ovary of zebrafish and functional dysregulation such as depletion of glycogen in liver, retrobulbar edema, degeneration of nasal neurosensory epithelium, underdevelopment of intestine, and diminution in the fraction of ovarian follicles containing vitellogenic oocytes. Importantly, lesions in nasal epithelium and evidence of endocrine disruption based on alternatively spliced vasa transcripts are two novel and significant results of this study. Microarray gene expression analysis comparing vehicle control to dietary TCDD revealed dysregulated genes involved in pathways associated with cardiac necrosis/cell death, cardiac fibrosis, renal necrosis/cell death and liver necrosis/cell death. These baseline toxicological effects provide evidence for the potential mechanisms of developmental dysfunctions induced by TCDD and vasa as a biomarker for ovarian developmental disruption. PMID:24988445

  6. Dietary exposure to aluminium in the popular Chinese fried bread youtiao.

    PubMed

    Li, Ge; Zhao, Xue; Wu, Shimin; Hua, Hongying; Wang, Qiang; Zhang, Zhiheng

    2017-06-01

    Youtiao is a typical, traditional and widely consumed fried food in China. Fermentation of youtiao involves the use of aluminium potassium sulphate (alum). There are health concerns related to the levels of aluminium in food; therefore, we aimed to determine the aluminium concentrations of youtiao from various locations, and to estimate the dietary exposure by different age groups in southern and northern China. The aluminium content of youtiao samples varied considerably (range = 4.46-852.69 mg kg(-1)). Both the mean and median aluminium contents of youtiao exceeded 100 mg kg(-1), which is the China National Standard (GB) 2760-2014 National Food Safety for Standards for food additives. However, the median and 97.5th percentile of weekly dietary exposure to aluminium from youtiao, estimated using Monte Carlo simulation, did not exceed the provisional tolerable weekly intake (PTWI) set by the joint FAO/WHO Expert Committee on Food Additives (JECFA) for children, adolescents, adults and seniors. The weekly dietary exposure to aluminium would exceed the PTWI if children, adolescents, adults and seniors consumed 134.47, 260.98, 327.10 or 320.41 g of youtiao per week, respectively.

  7. Prenatal Exposure to Nitrosatable Drugs, Dietary Intake of Nitrites, and Preterm Birth.

    PubMed

    Vuong, Ann M; Shinde, Mayura U; Brender, Jean D; Shipp, Eva M; Huber, John C; Sharkey, Joseph R; McDonald, Thomas J; Werler, Martha M; Kelley, Katherine E; Griesenbeck, John S; Langlois, Peter H; Canfield, Mark A

    2016-04-01

    Prenatal exposure to nitrosatable drugs, including secondary or tertiary amines, has been associated with preterm birth. Associations may be accentuated by higher intakes of dietary nitrites because of the increased formation of N-nitroso compounds. Using data from mothers of babies without major birth defects (controls) from the National Birth Defects Prevention Study, we examined the relationship between nitrosatable drug exposure in conjunction with dietary nitrite intake and preterm birth among 496 mothers of preterm infants and 5,398 mothers with full-term deliveries in 1997-2005. A protective association was observed with a high intake of plant nitrites (adjusted hazard ratio (AHR) = 0.72, 95% confidence interval (CI): 0.53, 0.97). Secondary amines in conjunction with high nitrite intake were associated with preterm birth during the first (AHR = 1.84, 95% CI: 1.14, 2.98), second (AHR = 1.89, 95% CI: 1.17, 3.07), and third (AHR = 2.00, 95% CI: 1.22, 3.29) trimesters. The adjusted hazard ratios for tertiary amine use in the third trimester by increasing tertiles of nitrite intake were 0.67 (95% CI: 0.35, 1.31), 1.25 (95% CI: 0.71, 2.19), and 2.02 (95% CI: 1.17, 3.49). Prenatal exposure to nitrosatable drugs, particularly secondary and tertiary amines, in conjunction with higher levels of dietary nitrite intake may increase the risk of preterm birth.

  8. Early life exposure to a high fat diet promotes long-term changes in dietary preferences and central reward signaling.

    PubMed

    Teegarden, S L; Scott, A N; Bale, T L

    2009-09-15

    Overweight and obesity in the United States continues to grow at epidemic rates in large part due to the overconsumption of calorically-dense palatable foods. Identification of factors influencing long-term macronutrient preferences may elucidate points of prevention and behavioral modification. In our current study, we examined the adult macronutrient preferences of mice acutely exposed to a high fat diet during the third postnatal week. We hypothesized that the consumption of a high fat diet during early life would alter the programming of central pathways important in adult dietary preferences. As adults, the early-exposed mice displayed a significant preference for a diet high in fat compared to controls. This effect was not due to diet familiarity as mice exposed to a novel high carbohydrate diet during this same early period failed to show differences in macronutrient preferences as adults. The increased intake of high fat diet in early exposed mice was specific to dietary preferences as no changes were detected for total caloric intake or caloric efficiency. Mechanistically, mice exposed to a high fat diet during early life exhibited significant alterations in biochemical markers of dopamine signaling in the nucleus accumbens, including changes in levels of phospho-dopamine and cyclic AMP-regulated phosphoprotein, molecular weight 32 kDa (DARPP-32) threonine-75, DeltaFosB, and cyclin-dependent kinase 5. These results support our hypothesis that even brief early life exposure to calorically-dense palatable diets alters long-term programming of central mechanisms important in dietary preferences and reward. These changes may underlie the passive overconsumption of high fat foods contributing to the increasing body mass in the western world.

  9. Pediatric acute lymphoblastic leukemia and exposure to pesticides.

    PubMed

    Soldin, Offie P; Nsouli-Maktabi, Hala; Nsouly-Maktabi, Hala; Genkinger, Jeanine M; Loffredo, Christopher A; Ortega-Garcia, Juan Antonio; Colantino, Drew; Barr, Dana B; Luban, Naomi L; Shad, Aziza T; Nelson, David

    2009-08-01

    Organophosphates are pesticides ubiquitous in the environment and have been hypothesized as one of the risk factors for acute lymphoblastic leukemia (ALL). In this study, we evaluated the associations of pesticide exposure in a residential environment with the risk for pediatric ALL. This is a case-control study of children newly diagnosed with ALL, and their mothers (n = 41 child-mother pairs) recruited from Georgetown University Medical Center and Children's National Medical Center in Washington, DC, between January 2005 and January 2008. Cases and controls were matched for age, sex, and county of residence. Environmental exposures were determined by questionnaire and by urinalysis of pesticide metabolites using isotope dilution gas chromatography-high-resolution mass spectrometry. We found that more case mothers (33%) than controls (14%) reported using insecticides in the home (P < 0.02). Other environmental exposures to toxic substances were not significantly associated with the risk of ALL. Pesticide levels were higher in cases than in controls (P < 0.05). Statistically significant differences were found between children with ALL and controls for the organophosphate metabolites diethylthiophosphate (P < 0.03) and diethyldithiophosphate (P < 0.05). The association of ALL risk with pesticide exposure merits further studies to confirm the association.

  10. Pediatric Acute Lymphoblastic Leukemia and Exposure to Pesticides

    PubMed Central

    Soldin, Offie P.; Nsouly-Maktabi, Hala; Genkinger, Jeanine M.; Loffredo, Christopher A.; Ortega-Garcia, Juan Antonio; Colantino, Drew; Barr, Dana B.; Luban, Naomi L.; Shad, Aziza T.; Nelson, David

    2013-01-01

    Organophosphates are pesticides ubiquitous in the environment and have been hypothesized as one of the risk factors for acute lymphoblastic leukemia (ALL). In this study, we evaluated the associations of pesticide exposure in a residential environment with the risk for pediatric ALL. This is a case–control study of children newly diagnosed with ALL, and their mothers (n = 41 child–mother pairs) were recruited from Georgetown University Medical Center and Children's National Medical Center in Washington, DC, between January 2005 and January 2008. Cases and controls were matched for age, sex, and county of residence. Environmental exposures were determined by questionnaire and by urinalysis of pesticide metabolites using isotope dilution gas chromatography–high-resolution mass spectrometry. We found that more case mothers (33%) than controls (14%) reported using insecticides in the home (P < 0.02). Other environmental exposures to toxic substances were not significantly associated with the risk of ALL. Pesticide levels were higher in cases than in controls (P < 0.05). Statistically significant differences were found between children with ALL and controls for the organophosphate metabolites diethylthiophosphate (P < 0.03) and diethyldithiophosphate (P < 0.05). The association of ALL risk with pesticide exposure merits further studies to confirm the association. PMID:19571777

  11. Relationships between children's exposure to ethnic produce and their dietary behaviors.

    PubMed

    Chen, Qiong; Goto, Keiko; Wolff, Cindy; Zhao, Yanling

    2015-04-01

    The current study examined relationships between children's ethnic produce exposure and healthy dietary practices among Latino, Hmong and non-Hispanic white children. One hundred Latino, 100 Hmong, and 92 non-Hispanic white parents of children ages 5-8 years old in northern California completed a cross-sectional survey. Children's exposure to ethnic produce from Hmong and Latino cultures, overall fruit and vegetable consumption, and fast food and ethnic restaurant use were measured. The Kruskal-Wallis and Mann-Whitney tests were used to compare variables across different ethnic groups. Spearman's correlation was used to assess the relationship between variables. Children's overall ethnic produce exposure, as well as exposure to produce from other cultures, was significantly correlated with overall fruit and vegetable consumption. There was a marginal (p = 0.053) negative association between ethnic produce exposure and fast food restaurant use among Latino children. These findings suggest that promoting ethnic produce is an effective strategy for enhancing healthy dietary practices among children.

  12. Assessing infant exposure to persistent organic pollutants via dietary intake in Australia.

    PubMed

    Toms, Leisa-Maree Leontjew; Hearn, Laurence; Mueller, Jochen F; Harden, Fiona A

    2016-01-01

    Persistent organic pollutants (POPs) including polybrominated diphenyl ethers (PBDEs); organochlorine pesticides (OCPs); and polychlorinated biphenyls (PCBs) persist in the environment, bioaccumulate, and pose a risk of causing adverse human health effects. Typically, exposure assessments undertaken by modeling existing intake data underestimate the concentrations of these chemicals in infants. This study aimed to determine concentrations of POPs in infant foods, assess exposure via dietary intake and compare this to historical exposure. Fruit purees, meat and vegetables, dairy desserts, cereals and jelly foods (n = 33) purchased in 2013 in Brisbane, Australia were analyzed. For OCPs and PCBs, concentrations ranged up to 95 pg/g fw and for PBDEs up to 32 pg/g fw with most analytes below the limit of detection. Daily intake is dependent on type and quantity of foods consumed. Consumption of a 140 g meal would result in intake ranging from 0 to 4.2 ng/day, 4.4 ng/day and 13.3 ng/day, for OCPs, PBDEs and PCBs, respectively. PBDEs were detected in 3/33 samples, OCPs in 9/33 samples and PCBs in 13/33 samples. Results from this study indicate exposure for infants via dietary (in contrast to dust and breast milk) intake in Australia contribute only a minor component to total exposure. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. An assessment of dietary exposure to glyphosate using refined deterministic and probabilistic methods.

    PubMed

    Stephenson, C L; Harris, C A

    2016-09-01

    Glyphosate is a herbicide used to control broad-leaved weeds. Some uses of glyphosate in crop production can lead to residues of the active substance and related metabolites in food. This paper uses data on residue levels, processing information and consumption patterns, to assess theoretical lifetime dietary exposure to glyphosate. Initial estimates were made assuming exposure to the highest permitted residue levels in foods. These intakes were then refined using median residue levels from trials, processing information, and monitoring data to achieve a more realistic estimate of exposure. Estimates were made using deterministic and probabilistic methods. Exposures were compared to the acceptable daily intake (ADI)-the amount of a substance that can be consumed daily without an appreciable health risk. Refined deterministic intakes for all consumers were at or below 2.1% of the ADI. Variations were due to cultural differences in consumption patterns and the level of aggregation of the dietary information in calculation models, which allows refinements for processing. Probabilistic exposure estimates ranged from 0.03% to 0.90% of the ADI, depending on whether optimistic or pessimistic assumptions were made in the calculations. Additional refinements would be possible if further data on processing and from residues monitoring programmes were available.

  14. Secondhand smoke exposure induces acutely airway acidification and oxidative stress.

    PubMed

    Kostikas, Konstantinos; Minas, Markos; Nikolaou, Eftychia; Papaioannou, Andriana I; Liakos, Panagiotis; Gougoura, Sofia; Gourgoulianis, Konstantinos I; Dinas, Petros C; Metsios, Giorgos S; Jamurtas, Athanasios Z; Flouris, Andreas D; Koutedakis, Yiannis

    2013-02-01

    Previous studies have shown that secondhand smoke induces lung function impairment and increases proinflammatory cytokines. The aim of the present study was to evaluate the acute effects of secondhand smoke on airway acidification and airway oxidative stress in never-smokers. In a randomized controlled cross-over trial, 18 young healthy never-smokers were assessed at baseline and 0, 30, 60, 120, 180 and 240 min after one-hour secondhand smoke exposure at bar/restaurant levels. Exhaled NO and CO measurements, exhaled breath condensate collection (for pH, H(2)O(2) and NO(2)(-)/NO(3)(-) measurements) and spirometry were performed at all time-points. Secondhand smoke exposure induced increases in serum cotinine and exhaled CO that persisted until 240 min. Exhaled breath condensate pH decreased immediately after exposure (p < 0.001) and returned to baseline by 180 min, whereas H(2)O(2) increased at 120 min and remained increased at 240 min (p = 0.001). No changes in exhaled NO and NO(2)/NO(3) were observed, while decreases in FEV(1) (p < 0.001) and FEV(1)/FVC (p < 0.001) were observed after exposure and returned to baseline by 180 min. A 1-h exposure to secondhand smoke induced airway acidification and increased airway oxidative stress, accompanied by significant impairment of lung function. Despite the reversal in EBC pH and lung function, airway oxidative stress remained increased 4 h after the exposure. Clinical trial registration number (EudraCT): 2009-013545-28. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. TIM Version 3.0 beta Technical Description and User Guide - Appendix F - Approach for Calculating Juvenile Dietary Exposure

    EPA Pesticide Factsheets

    Use the available information on the relationship between juvenile body weights and energetic requirements to develop a general approach for calculating juvenile dietary exposure doses appropriate for a range of avian species.

  16. Bioaccumulation of silver in Daphnia magna: Waterborne and dietary exposure to nanoparticles and dissolved silver.

    PubMed

    Ribeiro, Fabianne; Van Gestel, Cornelis A M; Pavlaki, Maria D; Azevedo, Sofia; Soares, Amadeu M V M; Loureiro, Susana

    2017-01-01

    Silver nanoparticles (Ag-NP) are incorporated into commercial products as antimicrobial agents, which potentiate their emission to the environment. The toxicity of Ag-NP has been associated with the release of Ag ions (Ag(+)), which are more toxic to aquatic organisms than Ag-NP. In this study, a toxicokinetics approach was applied to compare the potential of Daphnia magna to accumulate Ag from either Ag-NP or AgNO3 through different exposure routes: a) water, b) diet and c) water and diet. A one-compartment kinetics model was applied to describe the development of Ag body concentrations over time and derive uptake (k1w; k1d) and elimination (k2) rate constants. Under water-only exposure, AgNO3 induced higher Ag uptake rate constants and bioconcentration factors when compared to Ag-NP. For dietary exposure, no differences in Ag concentrations in D. magna, along with the kinetics parameters, were found for both Ag forms. Simultaneous water and dietary exposures to Ag-NP induced higher Ag concentrations in D. magna compared to AgNO3. In this combined exposure, uptake from water explains most for the increase in Ag body concentration in D. magna for Ag-NP exposure, whereas uptake from the diet was the major contributor for the increase in Ag concentration in D. magna under AgNO3 exposure. Biomagnification was not observed for any of the exposure routes applied in this study, neither for Ag-NP nor for AgNO3.

  17. Environmental and dietary exposure of young children to inorganic trace elements.

    PubMed

    Glorennec, Philippe; Lucas, Jean-Paul; Mercat, Anne-Camille; Roudot, Alain-Claude; Le Bot, Barbara

    2016-12-01

    Children are exposed to toxic metals and metalloids via their diet and environment. Our objective was to assess the aggregate chronic exposure of children aged 3-6years, living in France, to As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V present in diet, tap water, air, soil and floor dust in the years 2007-2009. Dietary data came from the French Total Diet Study, while concentrations in residential tap water, soil and indoor floor dust came from the 'Plomb-Habitat' nationwide representative survey on children's lead exposure at home. Indoor air concentrations were assumed to be equal to outdoor air concentrations, which were retrieved from regulatory measurements networks. Human exposure factors were retrieved from literature. Data were combined with Monte Carlo simulations. Median exposures were 1.7, 0.3, 10.2, 34.1, 60.3, 0.7, 0.1, 44.3, 1.5 and 95th percentiles were 4.4, 0.5, 15.8, 61.3, 98.3, 2.5, 0.1, 111.1, 2.9μg/kgbw/d for As, Cd, Cr, Cu, Mn, Pb, Sb, Sr, and V respectively. Dietary exposures dominate aggregate exposures, with the notable exception of Pb - for which soils and indoor floor dust ingestion contribute most at the 95th percentile. The strengths of this study are that it aggregates exposures that are often estimated separately, and uses a large amount of representative data. This assessment is limited to main diet and residential exposure, and does not take into account the relative bioavailability of compounds. These results could be used to help target prevention strategies.

  18. Arsenic: bioaccessibility from seaweed and rice, dietary exposure calculations and risk assessment.

    PubMed

    Brandon, Esther F A; Janssen, Paul J C M; de Wit-Bos, Lianne

    2014-01-01

    Arsenic is a metalloid that occurs in food and the environment in different chemical forms. Inorganic arsenic is classified as a class I carcinogen. The inorganic arsenic intake from food and drinking water varies depending on the geographic arsenic background. Non-dietary exposure to arsenic is likely to be of minor importance for the general population within the European Union. In Europe, arsenic in drinking water is on average low, but food products (e.g. rice and seaweed) are imported from all over the world including from regions with naturally high arsenic levels. Therefore, specific populations living in Europe could also have a high exposure to inorganic arsenic due to their consumption pattern. Current risk assessment is based on exposure via drinking water. For a good estimation of the risks of arsenic in food, it is important to investigate if the bioavailability of inorganic arsenic from food is different from drinking water. The present study further explores the issue of European dietary exposure to inorganic arsenic via rice and seaweed and its associated health risks. The bioavailability of inorganic arsenic was measured in in vitro digestion experiments. The data indicate that the bioavailability of inorganic arsenic is similar for rice and seaweed compared with drinking water. The calculated dietary intake for specific European Union populations varied between 0.44 and 4.51 µg kg⁻¹ bw day⁻¹. The margins of exposure between the inorganic intake levels and the BMDL0.5 values as derived by JECFA are low. Decreasing the intake of inorganic arsenic via Hijiki seaweed could be achieved by setting legal limits similar to those set for rice by the Codex Alimentarius Commission in July 2014.

  19. Reproductive toxicity assessment of chronic dietary exposure to soy isoflavones in male rats.

    PubMed

    Faqi, Ali S; Johnson, William D; Morrissey, Robert L; McCormick, David L

    2004-06-01

    Epidemiologic and experimental data suggest that consumption of diets that are rich in isoflavones may decrease cancer risk in the breast, prostate, and other tissues. Isoflavones such as genistein and daidzein are structurally similar to endogenous estrogens, and demonstrate both estrogenic and weak anti-estrogenic activities; these activities may underlie the impaired fertility and reproductive tract disorders reported in animals exposed to high doses of isoflavones. To identify possible effects of isoflavones on male fertility, we evaluated reproductive parameters in Wistar-Unilever rats receiving dietary exposure to PTI G-2535, a characterized mixture of soy-derived isoflavones containing 45% genistein, 23% daidzein, and 4% glycitein. Beginning at 10 weeks of age, rats received chronic dietary exposure to the soy isoflavone mixture (200 or 2000 mg/kg diet) for a minimum of 12 months. Controls received unsupplemented chow diet only for the same period. Dietary exposure to isoflavones induced no gross toxicity or alterations in body weight gain. Absolute and relative weights of the testis and epididymis in groups receiving high or low doses of isoflavones were comparable to those of controls, and histopathologic evaluations demonstrated that testicular morphology was similar in all study groups. Isoflavone exposure had no significant effects on spermatid count, sperm production, or sperm morphology in any group. These data suggest that the reproductive system of adult male rats is relatively insensitive to isoflavone toxicity at dose levels that demonstrate significant activity in cancer chemoprevention, and that male reproductive function is unlikely to be affected by long-term administration of isoflavones for cancer prevention or other purposes. The results of this study conducted in adult male rats differ from the significant alterations in reproductive parameters that have been reported in female rats receiving prenatal or juvenile exposure to isoflavones.

  20. Effects of Acute Exposures to Carbon Dioxide upon Cognitive Functions

    NASA Technical Reports Server (NTRS)

    Ryder, V. E.; Scully, R. R.; Alexander, D. J.; Lam, C. W.; Young, M.; Satish, U.; Basner, M.

    2017-01-01

    Carbon dioxide (CO2) originates from human metabolism and typically remains about 10-fold higher in concentration on the International Space Station (ISS) than at the earth's surface. There have been recurring complaints by crew members of episodes of "mental viscosity" adversely affecting their performance, and there is evidence from the ISS that associates CO2 levels with reports of headaches by crewmembers. Consequently, flight rules have been employed to control CO2 below 3 mm Hg, which is well below the existing Spacecraft Maximum Allowable Concentration (SMAC) of 10 mm Hg for 24-hour exposures, and 5.3 mm Hg for exposures of 7 to 180 days. Headaches, while sometime debilitating themselves, are also symptoms that can provide evidence that physiological defense mechanisms have been breached, and there is evidence that CO2 has effects at levels below the threshold for headaches. This concern appears to be substantiated in reports that CO2 at concentrations below 2 mm Hg substantially reduced some cognitive functions that are associated with the ability to make complex decisions in conditions that are characterized by volatility, uncertainty, complexity, ambiguity, and delayed feedback. These are conditions that could be encountered by crews in off-nominal situations or during the first missions beyond low earth orbit. Therefore, we set out to determine if decision-making under volatile, uncertain, confusing and ambiguous circumstances, where feedback is delayed or absent, is correlated with low levels of CO2 during acute exposures (several hours) in crew-like subjects and to determine if additional cognitive domains are sensitive to concentrations of CO2 at, or below, current ISS levels by using a test battery that is currently available onboard ISS. We enrolled 22 volunteers (8 females, 14 males) between the ages of 30-55 (38.8 +/- 7.0) years whose training and professional experience reflect that of the astronaut corps. Subjects were divided among 4 study

  1. Assessment of dietary exposure to organohalogen contaminants, legacy and emerging flame retardants in a Norwegian cohort.

    PubMed

    Xu, Fuchao; Tay, Joo-Hui; Covaci, Adrian; Padilla-Sánchez, Juan Antonio; Papadopoulou, Eleni; Haug, Line Småstuen; Neels, Hugo; Sellström, Ulla; de Wit, Cynthia A

    2017-03-20

    Polychlorinated biphenyls (PCBs), organochlorine pesticides (OCPs), polybrominated diphenyl ethers (PBDEs), emerging halogenated flame retardants (EHFRs) and organophosphate flame retardants (PFRs) were detected in 24h duplicate diet samples from a Norwegian cohort (n=61), with concentrations ranging from dietary exposure assessment was conducted for each participant based on individual body weight and contaminant concentrations in their collected duplicate diet samples. The estimated median (95th percentile) dietary exposures for ΣPFR, ΣPCB, ΣOCP, ΣPBDE, and ΣEHFR were 87 (340), 5.8 (27), 11 (31), 1.3 (14), and <0.01 (3.4) ng/kgbw/day, respectively. The median and 95th percentile dietary exposures of most of the target analytes did not exceed the reference dose (RfD), except for PCBs where 16% of the participants exceeded the RfD. However, a relatively short period of such high intake is not expected to result in any adverse health effects. Participants of this cohort were exposed to higher levels of EHDPHP than any other FRs. Fish was the major dietary route for PCB, OCP and PBDE exposure, while meat was the main dietary exposure route for PFRs.

  2. Inhalation exposure system used for acute and repeated-dose methyl isocyanate exposures of laboratory animals.

    PubMed

    Adkins, B; O'Connor, R W; Dement, J M

    1987-06-01

    Laboratory animals were exposed by inhalation for 2 hr/day (acute) or 6 hr/day (four consecutive days, repeated dose) to methyl isocyanate (MIC). Exposures were conducted in stainless steel and glass inhalation exposure chambers placed in stainless steel, wire mesh cages. MIC was delivered with nitrogen via stainless steel and Teflon supply lines. Chamber concentrations ranged from 0 to 60 ppm and were monitored continuously with infrared spectrophotometers to 1 ppm and at 2-hr intervals to 20 ppb with a high performance liquid chromatograph equipped with a fluorescence detector. Other operational parameters monitored on a continuous basis included chamber temperature (20-27 degrees C), relative humidity (31-64%), static (transmural) pressure (-0.3 in.), and flow (300-500 L/min). The computer-assistance system interfaced with the inhalation exposure laboratory is described in detail, including the analytical instrumentation calibration system used throughout this investigation.

  3. THERMOREGULATION IN THE RAT DURING CHRONIC, DIETARY EXPOSURE TO CHLORPYRIFOS, AN ORGANOPHOSPHATE INSECTICIDE.

    EPA Science Inventory

    Administration of chlorpyrifos (CHP) at a dose of 25 to 80 mg/kg (p.o.) To rats results in hypothermia followed by a fever lasting for several days. To understand if chronic, low level exposure to CHP affects thermoregulation in a comparable manner to acute administration, male L...

  4. THERMOREGULATION IN THE RAT DURING CHRONIC, DIETARY EXPOSURE TO CHLORPYRIFOS, AN ORGANOPHOSPHATE INSECTICIDE.

    EPA Science Inventory

    Administration of chlorpyrifos (CHP) at a dose of 25 to 80 mg/kg (p.o.) To rats results in hypothermia followed by a fever lasting for several days. To understand if chronic, low level exposure to CHP affects thermoregulation in a comparable manner to acute administration, male L...

  5. Testing a cumulative and aggregate exposure model using biomonitoring studies and dietary records for Italian vineyard spray operators.

    PubMed

    Kennedy, Marc C; Glass, C Richard; Fustinoni, Silvia; Moretto, Angelo; Mandic-Rajcevic, Stefan; Riso, Patrizia; Turrini, Aida; van der Voet, Hilko; Hetmanski, Michel T; Fussell, Richard J; van Klaveren, Jacob D

    2015-05-01

    The need for improved tools to estimate the cumulative and aggregate exposure to compounds such as plant protection products (PPPs) is recognised in the EU Regulation 1107/2009. A new model has been developed to estimate the exposure within a population to single compounds or compounds within a Cumulative Action Group, considering dietary and non-dietary sources and multiple exposure routes. To test the model a field study was carried out in Italy with operators applying tebuconazole fungicides, with measurements of dermal exposure collected. Whole urine samples were collected and analysed to provide values for the absorbed dose of tebuconazole, with duplicate diet samples collected and analysed as a measure of dietary exposures. The model provided predicted values of exposure for combined dietary and non-dietary routes of exposures which were compared to the measured absorbed dose values based on urinary analysis. The model outputs provided mean daily exposure values of 1.77 (± 1.96) µg a.s./kg BW which are comparable to measured mean values from the biomonitoring field study of 1.73 (± 1.31) µg a.s./kg BW. To supplement the limited measurement data available, comparisons against other models were also made and found to be comparable.

  6. Acute exposure of rabbits to diphenyl diselenide: a toxicological evaluation.

    PubMed

    Straliotto, Marcos Raniel; Mancini, Gianni; de Oliveira, Jade; Nazari, Evelise Maria; Müller, Yara Maria Rauh; Dafre, Alcir; Ortiz, Susana; Silva, Edson Luiz; Farina, Marcelo; Latini, Alexandra; Rocha, João Batista Teixeira; de Bem, Andreza Fabro

    2010-11-01

    The simple organoselenium compound diphenyl diselenide (PhSe)(2) is a promising new pharmacological agent. However, few toxicological evaluations of this molecule have been reported. We evaluated the effects of acute administration of (PhSe)(2) on toxicological parameters in rabbits. Adult New Zealand rabbits were exposed to (PhSe)(2) (5-500 micromol kg(-1) , intraperitoneally) once a day for 5 days. Exposure to 500 micromol kg(-1) caused 85% mortality. Exposure to 50 micromol kg(-1) of (PhSe)(2) increased the glutathione levels in the hippocampus, kidney, heart, muscle and blood, whereas lipoperoxidation (TBARS) decreased in the cerebellum and kidney after exposure to 5 micromol kg(-1) . The activity of glutathione peroxidase increased in the heart and muscle of rabbits treated with 50 micromol kg(-1) of (PhSe)(2) and glutathione reductase activity was reduced in the cerebellum, cerebral cortex and kidney. Treatment with (PhSe)(2) reduced the activity of δ-aminolevulinate dehydratase in the hippocampus and increased this activity in the heart, but did not alter the activity of complexes I and II of the respiratory chain in the liver and brain. Hepatic and renal biochemical and histological parameters were not modified by (PhSe)(2) and apoptosis was not detected in these tissues; however, the hepatic cells tended to accumulate fat vacuoles. These results indicated that acute toxicology to (PhSe)(2) in rabbit is dependent on the dose, which should motivate further experiments on the therapeutic properties of this compound. 2010 John Wiley & Sons, Ltd.

  7. Dietary selenomethionine exposure alters swimming performance, metabolic capacity and energy homeostasis in juvenile fathead minnow.

    PubMed

    McPhee, D Landon; Janz, David M

    2014-10-01

    Selenium (Se) is known to cause chronic toxicity in aquatic species. In particular, dietary exposure of fish to selenomethionine (SeMet), the primary form of Se in the diet, is of concern. Recent studies suggest that chronic exposure to elevated dietary SeMet alters energy and endocrine homeostasis in adult fish. However, little is known about the direct effects of dietary SeMet exposure in juvenile fish. The objective of the present study was to investigate sublethal physiological effects of dietary SeMet exposure in juvenile fathead minnow (Pimephales promelas). Twenty days-post-hatch fathead minnow were exposed for 60 days to different measured concentrations (2.8, 5.4, 9.9, 26.5 μg Se/g dry mass [dm]) of Se in food in the form of SeMet. After exposure, samples were collected for Se analysis and fish were subjected to a swimming performance challenge to assess critical swim speed (Ucrit), tail beat frequency and tail beat amplitude, oxygen consumption (MO2), cost of transport (COT), standard metabolic rate (SMR), active metabolic rate (AMR), and factorial aerobic scope (F-AS). Ucrit was decreased in the 26.5 μg Se/g dm exposure group compared to the control group. Tail beat frequency and tail beat amplitude were significantly reduced in fish fed 9.9 and 26.5 μg Se/g. An increase in MO2 and COT was observed in the 9.9 and 26.5 μg Se/g exposure groups compared to the control group. While the AMR of the high dose group was increased relative to control, there were no significant differences in SMR and F-AS. Energy storage capacity was measured via whole body triglyceride and glycogen concentrations. Triglyceride concentrations in non-swam fish were elevated in the 5.4 μg Se/g group relative to controls. Fatigued (swam) fish had significantly lower whole body triglycerides than non-swam fish. All non-swam SeMet exposure groups had significantly decreased whole body glycogen concentrations compared to controls, while the 5.4 and 26.5 μg Se/g exposure groups had

  8. Acute effects of acrolein in human volunteers during controlled exposure

    PubMed Central

    Dwivedi, Aishwarya M.; Johanson, Gunnar; Lorentzen, Johnny C.; Palmberg, Lena; Sjögren, Bengt; Ernstgård, Lena

    2015-01-01

    Abstract Context: Acrolein is a reactive aldehyde mainly formed by combustion. The critical effect is considered to be irritation of the eyes and airways; however, the scarce data available make it difficult to assess effect levels. Objective: The aim of the study was to determine thresholds for acute irritation for acrolein. Methods: Nine healthy volunteers of each sex were exposed at six occasions for 2 h at rest to: clean air, 15 ppm ethyl acetate (EA), and 0.05 ppm and 0.1 ppm acrolein with and without EA (15 ppm) to mask the potential influence of odor. Symptoms related to irritation and central nervous system effects were rated on 100-mm Visual Analogue Scales. Results: The ratings of eye irritation were slightly but significantly increased during exposure to acrolein in a dose-dependent manner (p < 0.001, Friedman test) with a median rating of 8 mm (corresponding to “hardly at all”) at the 0.1 ppm condition and with no influence from EA. No significant exposure-related effects were found for pulmonary function, or nasal swelling, nor for markers of inflammation and coagulation in blood (IL-6, C-reactive protein, serum amyloid A, fibrinogen, factor VIII, von Willebrand factor, and Clara cell protein) or induced sputum (cell count, differential cell count, IL-6 and IL-8). Blink frequency recorded by electromyography was increased during exposure to 0.1 ppm acrolein alone but not during any of the other five exposure conditions. Conclusion: Based on subjective ratings, the present study showed minor eye irritation by exposure to 0.1 ppm acrolein. PMID:26635308

  9. The effect of dietary intake changes on nutritional status in acute leukaemia patients after first induction chemotherapy.

    PubMed

    Malihi, Z; Kandiah, M; Chan, Y M; Esfandbod, M; Vakili, M; Hosseinzadeh, M; Zarif Yeganeh, M

    2015-07-01

    This study aimed to evaluate how changes in dietary intake among acute lymphoblastic and acute myeloid leukaemia (ALL and AML) patients affect nutritional status after the first induction chemotherapy. Dietary intake was assessed using 24-h recall and a 136-item food frequency questionnaire. Nutritional status was assessed by Patients Subjective Global Assessment questionnaire before starting induction therapy and again after 1 month. All newly diagnosed acute leukaemia patients aged 15 years old and older who attended three referral hospitals for initiation of their induction chemotherapy were included in the sample selection provided that they gave informed consent. A total of 30 AML and 33 ALL patients participated in the study. Dietary intake and nutritional status worsened after the chemotherapy treatment. Dietary intake in terms of macronutrients, micronutrients, food variety and diet diversity score changed significantly after the induction chemotherapy. No significant relationship was found between the changes in dietary indices and nutritional status. Chemotherapy-related side effects as an additional factor to cancer itself could affect dietary intake of leukaemia patients. The effectiveness of an early assessment of nutritional status and dietary intake should be further investigated in order to deter further deterioration. © 2014 The Authors. European Journal of Cancer Care Published by John Wiley & Sons Ltd.

  10. Gender differences in TBT accumulation and transformation in Thais clavigera after aqueous and dietary exposure.

    PubMed

    Wang, Xinhong; Fang, Chao; Hong, Huasheng; Wang, Wen-Xiong

    2010-09-01

    In this study, female and male Thais clavigera whelks were exposed to aqueous and dietary (using oysters as the prey) tributyltin (TBT) for up to 45 days, followed by a 30-day depuration, in order to examine the gender differences in TBT accumulation and transformation. The metabolites of TBT [dibutyltin (DBT) and monobutyltin (MBT)] were also measured in different tissues of the whelks (digestive, reproductive and remaining organs) during the exposure and depuration periods. By the end of the exposure period, all of the female whelks developed imposex after TBT exposure, and both the relative penis size index and the vas deferens sequence index were positively correlated with the tissue burden of TBT. However, biomagnification of TBT did not occur in the whelks. TBT was rapidly accumulated in their digestive and reproductive organs from both routes of exposure, and both elimination and biotransformation of TBT were also rapid. The redistribution of TBT among tissues was obvious during the exposure period but negligible during depuration. MBT was generally the major metabolite in each tissue, indicating a significant metabolism of TBT by the whelks. Accumulation, transformation, as well as elimination, were more significant following dietary exposure than following aqueous exposure. In particular, we observed gender-related differences in the biokinetics of TBT. Rapid biotransformation and elimination of TBT were detected in the male whelks, while the female whelks had higher bioaccumulation but lower elimination of TBT in their reproductive organs. Internal remobilization of TBT from digestive to reproductive organs was also more obvious in the females, indicating that the reproductive organs of females were the main targets of TBT accumulation.

  11. Dietary exposure to pesticide residues from foods of plant origin and drinks in Lebanon.

    PubMed

    Nasreddine, Lara; Rehaime, Maria; Kassaify, Zeina; Rechmany, Roula; Jaber, Farouk

    2016-08-01

    This study assesses the dietary exposure of Lebanese adults to 47 pesticide residues from both foods of plant origin and drinks. The study was conducted using the Total Diet Study protocol in two different areas of Lebanon: Greater Beirut (urban) and Keserwan (semi-rural). A total of 1860 individual foods were collected, prepared, and cooked prior to analysis. Composite samples of similar foods were analyzed, following the QuEChERS Multiresidue method. Eighteen residues were detected/quantified on at least one composite sample, with 66.7 % of the results being quantifiable and 33.3 % detectable. Quantifiable levels ranged between 10.3 and 208 μg/kg. For the composite samples where residues were detected, 55 % had one residue, while 45 % had 2-4 residues. The most frequently detected/quantified pesticide residues included Chlorpyrifos, Procymidone, Primiphos methyl, Dimethoate, and Dieldrin. The dietary exposure assessment was conducted using the deterministic approach with two scenarios: (1) the lower bound (LB) approach and (2) the upper bound (UB) approach. Using the LB approach, mean estimated daily exposures were far below the acceptable daily intakes (ADIs) for all investigated residues. Using the UB approach, which tends to overestimate exposure, mean estimated daily exposures were below the ADIs for all residues except for Dieldrin (semi-rural: 128.7 % ADI; urban: 100.7 % ADI). Estimates of mean exposure to Diazinon reached 50.3 % of ADI in the urban diet and 61.9 % in the semi-rural diet. Findings of this study identify specific pesticide residues as monitoring priorities for which more comprehensive and sensitive analyses are needed in order to refine exposure assessment.

  12. Dietary intake and its contribution to longitudinal organophosphorus pesticide exposure in urban/suburban children.

    PubMed

    Lu, Chensheng; Barr, Dana B; Pearson, Melanie A; Waller, Lance A

    2008-04-01

    The widespread use of organophosphorus (OP) pesticides has led to frequent exposure in adults and children. Because such exposure may cause adverse health effects, particularly in children, the sources and patterns of exposure need to be studied further. We assessed young urban/suburban children's longitudinal exposure to OP pesticides in the Children's Pesticide Exposure Study (CPES) conducted in the greater Seattle, Washington, area, and used a novel study design that allowed us to determine the contribution of dietary intake to the overall OP pesticide exposure. Twenty-three children 3-11 years of age who consumed only conventional diets were recruited for this 1-year study conducted in 2003-2004. Children switched to organic diets for 5 consecutive days in the summer and fall sampling seasons. We measured specific urinary metabolites for malathion, chlorpyrifos, and other OP pesticides in urine samples collected twice daily for a period of 7, 12, or 15 consecutive days during each of the four seasons. By substituting organic fresh fruits and vegetables for corresponding conventional food items, the median urinary metabolite concentrations were reduced to nondetected or close to non-detected levels for malathion and chlorpyrifos at the end of the 5-day organic diet intervention period in both summer and fall seasons. We also observed a seasonal effect on the OP urinary metabolite concentrations, and this seasonality corresponds to the consumption of fresh produce throughout the year. The findings from this study demonstrate that dietary intake of OP pesticides represents the major source of exposure in young children.

  13. Estimation of dietary exposure to acrylamide of Polish teenagers from an urban environment.

    PubMed

    Wyka, Joanna; Tajner-Czopek, Agnieszka; Broniecka, Anna; Piotrowska, Ewa; Bronkowska, Monika; Biernat, Jadwiga

    2015-01-01

    The aim of this study was to evaluate the dietary exposure to acrylamide (AA) in a group of teenagers (n = 261) from an urban environment. The intake of AA from food was estimated based on a 7-day food record diary (consecutive days). The food rations obtained (n = 1827) were used to calculate the amounts of the consumed food products, which were the main sources of AA. In the case of girls, the estimated dietary intake of AA per kg body weight (BW) amounted to 0.09 µg/kg BW/day (50th percentile), 0.32 µg/kg BW/day (75th percentile) and 1.04 µg/kg BW/day (95th percentile), and among boys it was 0.13, 0.41, and 1.18 µg/kg BW/day, respectively. The main sources of AA exposure were French fries, potato crisps, corn flakes, bread and salty sticks. The lowest values for margin of exposure (MOE) were calculated for the P95th percentiles of exposure, and ranged from 152 to 173. Copyright © 2014 Elsevier Ltd. All rights reserved.

  14. Assessing dietary exposure to cadmium in a metal recycling community in Vietnam: age and gender aspects.

    PubMed

    Ngo, Duc Minh; Hough, Rupert Lloyd; Le, Thi Thuy; Nyberg, Ylva; Le, Bach Mai; Nguyen, Cong Vinh; Nguyen, Manh Khai; Oborn, Ingrid

    2012-02-01

    This study estimates the dietary exposure to cadmium (Cd), and associated potential health risks, for individuals living and working in a metal recycling community (n=132) in Vietnam in comparison to an agricultural (reference) community (n=130). Individual-level exposure to Cd was estimated through analysis of staple foodstuffs combined with information from a food frequency questionnaire. Individual-level exposure estimates were compared with published 'safe' doses to derive a Hazard Quotient (HQ) for each member of the study population. Looking at the populations as a whole, there were no significant differences in the diets of the two villages. However, significantly more rice was consumed by working age adults (18-60 years) in the recycling village compared to the reference village (p<0.001). Rice was the main staple food with individuals consuming 461±162g/d, followed by water spinach (103±51kg/d). Concentrations of Cd in the studied foodstuffs were elevated in the metal recycling village. Values of HQ exceeded unity for 87% of adult participants of the metal recycling community (39% had a HQ>3), while 20% of adult participants from the reference village had an HQ>1. We found an elevated health risk from dietary exposure to Cd in the metal recycling village compared to the reference community. WHO standard of 0.4mg Cd/kg rice may not be protective where people consume large amounts of rice/have relatively low body weight.

  15. Reduced Triglyceride Secretion in Response to an Acute Dietary Fat Challenge in Obese Compared to Lean Mice

    PubMed Central

    Uchida, Aki; Whitsitt, Mary C.; Eustaquio, Trisha; Slipchenko, Mikhail N.; Leary, James F.; Cheng, Ji-Xin; Buhman, Kimberly K.

    2012-01-01

    Obesity results in abnormally high levels of triglyceride (TG) storage in tissues such as liver, heart, and muscle, which disrupts their normal functions. Recently, we found that lean mice challenged with high levels of dietary fat store TGs in cytoplasmic lipid droplets in the absorptive cells of the intestine, enterocytes, and that this storage increases and then decreases over time after an acute dietary fat challenge. The goal of this study was to investigate the effects of obesity on intestinal TG metabolism. More specifically we asked whether TG storage in and secretion from the intestine are altered in obesity. We investigated these questions in diet-induced obese (DIO) and leptin-deficient (ob/ob) mice. We found greater levels of TG storage in the intestine of DIO mice compared to lean mice in the fed state, but similar levels of TG storage after a 6-h fast. In addition, we found similar TG storage in the intestine of lean and DIO mice at multiple time points after an acute dietary fat challenge. Surprisingly, we found remarkably lower TG secretion from both DIO and ob/ob mice compared to lean controls in response to an acute dietary fat challenge. Furthermore, we found altered mRNA levels for genes involved in regulation of intestinal TG metabolism in lean and DIO mice at 6 h fasting and in response to an acute dietary fat challenge. More specifically, we found that many of the genes related to TG synthesis, chylomicron synthesis, TG storage, and lipolysis were induced in response to an acute dietary fat challenge in lean mice, but this induction was not observed in DIO mice. In fact, we found a significant decrease in intestinal mRNA levels of genes related to lipolysis and fatty acid oxidation in DIO mice in response to an acute dietary fat challenge. Our findings demonstrate altered TG handling by the small intestine of obese compared to lean mice. PMID:22375122

  16. Self-reported acute health symptoms and exposure to companion animals

    EPA Science Inventory

    Background: In order to understand the etiological burden of disease associated with acute health symptoms (e.g. gastrointestinal [GI], respiratory, dermatological), it is important to understand how common exposures influence these symptoms. Exposures to familiar and unfamiliar ...

  17. Self-reported acute health symptoms and exposure to companion animals

    EPA Science Inventory

    Background: In order to understand the etiological burden of disease associated with acute health symptoms (e.g. gastrointestinal [GI], respiratory, dermatological), it is important to understand how common exposures influence these symptoms. Exposures to familiar and unfamiliar ...

  18. Dietary exposure and risk assessment to lead of the population of Jiangsu province, China.

    PubMed

    Jin, Yingliang; Liu, Pei; Sun, Jinfang; Wang, Cannan; Min, Jie; Zhang, Yafei; Wang, Shiyuan; Wu, Yongning

    2014-01-01

    The paper's main purpose is to estimate the dietary exposure to lead for the inhabitants of Jiangsu province, China. Lead concentration data were obtained from the national food contamination monitoring programme during 2007-10. Food samples (n = 2077) were collected from 23 food categories in Jiangsu province. Consumption data were derived from Chinese national nutrition and health survey in 2002, which included 3938 inhabitants from 1451 households in Jiangsu province. Concentration data were combined with consumption data to estimate the dietary intake for the inhabitants of 2-6, 7-17 and 18-80 years, respectively. The β-binomial-normal (BBN) model was used to estimate the long-term intake for the population in Jiangsu province. The distribution of individual margin of exposure (IMoE) was introduced to assess the health effect. Uncertainty of IMoE was quantified by Monte Carlo and bootstrap methods. The mean levels of dietary exposure to lead were estimated at 3.019 µg kg(-1) bw day(-1) for children aged 2-6 years, 2.104 µg kg(-1) bw day(-1) for teenagers aged 7-17 years, and 1.601 µg kg(-1) bw day(-1) for adults aged 18-80 years. The mean intakes for the urban and rural populations were 1.494 and 1.822 µg kg(-1) bw day(-1), respectively. From the 25th to 99.9th percentiles, IMoE was 0.125-2.057 for 2-6 years and 0.473-7.998 for 18-80 years, respectively. The distribution of IMoE could indicate a public health concern on lead for the Chinese population in Jiangsu. Control measures should be taken to reduce lead exposure in Jiangsu province.

  19. Estimating pesticide exposure from dietary intake and organic food choices: the Multi-Ethnic Study of Atherosclerosis (MESA).

    PubMed

    Curl, Cynthia L; Beresford, Shirley A A; Fenske, Richard A; Fitzpatrick, Annette L; Lu, Chensheng; Nettleton, Jennifer A; Kaufman, Joel D

    2015-05-01

    Organophosphate pesticide (OP) exposure to the U.S. population is dominated by dietary intake. The magnitude of exposure from diet depends partly on personal decisions such as which foods to eat and whether to choose organic food. Most studies of OP exposure rely on urinary biomarkers, which are limited by short half-lives and often lack specificity to parent compounds. A reliable means of estimating long-term dietary exposure to individual OPs is needed to assess the potential relationship with adverse health effects. We assessed long-term dietary exposure to 14 OPs among 4,466 participants in the Multi-Ethnic Study of Atherosclerosis, and examined the influence of organic produce consumption on this exposure. Individual-level exposure was estimated by combining information on typical intake of specific food items with average OP residue levels on those items. In an analysis restricted to a subset of participants who reported rarely or never eating organic produce ("conventional consumers"), we assessed urinary dialkylphosphate (DAP) levels across tertiles of estimated exposure (n = 480). In a second analysis, we compared DAP levels across subgroups with differing self-reported organic produce consumption habits (n = 240). Among conventional consumers, increasing tertile of estimated dietary OP exposure was associated with higher DAP concentrations (p < 0.05). DAP concentrations were also significantly lower in groups reporting more frequent consumption of organic produce (p < 0.02). Long-term dietary exposure to OPs was estimated from dietary intake data, and estimates were consistent with DAP measurements. More frequent consumption of organic produce was associated with lower DAPs.

  20. Dietary and other environmental risk factors in acute leukaemias: a case-control study of 119 patients.

    PubMed

    Kwiatkowski, A

    1993-03-01

    Selected dietary risk factors and other environmental factors were studied in 119 adult patients (60 males and 59 females of the Cracow region) with acute leukaemia (91 acute myeloid leukaemia and 28 acute lymphoblastic leukaemia), by a case-control study method and logistic regression modelling of the risk of leukaemia. It was shown that the diet of patients with acute leukaemias before the onset of the disease differed qualitatively and quantitatively from that of healthy subjects of control groups. The risk of acute leukaemia was elevated in the subjects characterized by rare consumption of raw vegetables, frequent drinking of milk, frequent consumption of poultry, and drinking of soft water. Other environmental conditions connected with the dietary risk were: frequent viral infections, vaccination with the vaccinia virus, frequent use of aminophenazone, presence of fungi in the house, drinking of milk supplied from own's own cows, and frequent deaths of reared poultry.

  1. Acute exposure to UVB has a more profound effect on plant genome stability than chronic exposure.

    PubMed

    Boyko, Alex; Greer, Michael; Kovalchuk, Igor

    2006-12-01

    Environmental factors that damage DNA have various lengths of exposure and intensity levels. Although the results of increasing the intensity of a DNA damaging agent is often predictable, it is not clear whether the stage during development when the exposure is received has any influence on the amount of DNA damage. In this paper we analyzed the influence of UVB on the stability of Arabidopsis thaliana and the Nicotiana tabacum genomes. Our experiments showed that the acute exposure to UVB produces a significantly greater increase in homologous recombination frequency (HRF) and recombination rate (RR) compared with that produced by chronic exposure. The increase in HRF showed a positive correlation with UVB dose and a negative correlation with plant age. In other words, as the UVB dose was increased, there was a concomitant increase in HRF. Conversely, older plants had a lower HRF increase as compared to younger plants. Our experiments suggest that exposure to UVB makes the most significant impact on genome stability during the early stages of plant development.

  2. Relation of dietary inorganic arsenic exposure and urinary inorganic arsenic metabolites excretion in Japanese subjects.

    PubMed

    Oguri, Tomoko; Yoshinaga, Jun; Suzuki, Yayoi; Tao, Hiroaki; Nakazato, Tetsuya

    2017-06-03

    Inorganic arsenic (InAs) is a ubiquitous metalloid that has been shown to exert multiple adverse health outcomes. Urinary InAs and its metabolite concentration has been used as a biomarker of arsenic (As) exposure in some epidemiological studies, however, quantitative relationship between daily InAs exposure and urinary InAs metabolites concentration has not been well characterized. We collected a set of 24-h duplicated diet and spot urine sample of the next morning of diet sampling from 20 male and 19 female subjects in Japan from August 2011 to October 2012. Concentrations of As species in duplicated diet and urine samples were determined by using liquid chromatography-ICP mass spectrometry with a hydride generation system. Sum of the concentrations of urinary InAs and methylarsonic acid (MMA) was used as a measure of InAs exposure. Daily dietary InAs exposure was estimated to be 0.087 µg kg(-1) day(-1) (Geometric mean, GM), and GM of urinary InAs+MMA concentrations was 3.5 ng mL(-1). Analysis of covariance did not find gender-difference in regression coefficients as significant (P > 0.05). Regression equation Log 10 [urinary InAs+MMA concentration] = 0.570× Log 10 [dietary InAs exposure level per body weight] + 1.15 was obtained for whole data set. This equation would be valuable in converting urinary InAs concentration to daily InAs exposure, which will be important information in risk assessment.

  3. Dietary exposure to dioxins and dioxin-like PCBs in The Netherlands anno 2004.

    PubMed

    De Mul, Anika; Bakker, Martine I; Zeilmaker, Marco J; Traag, Wim A; Leeuwen, Stefan P J van; Hoogenboom, Ron L A P; Boon, Polly E; Klaveren, Jacob D van

    2008-08-01

    In this study, representative occurrence data for PCDD/Fs and dioxin-like PCBs in food were obtained and used to estimate dietary exposure of the Dutch population. Food composite samples were analyzed as well as single fish and vegetables samples. Total dioxin concentrations in animal products ranged from 0.05 pg TEQ/g product in poultry to 2.5 pg TEQ/g product (using TEF(2006)) in fish (shrimp), with 0.12pg TEQ/g product being the lowest concentrations measured in fish (tuna). In vegetable products, concentrations ranged from 0.00002 pg TEQ/g product (white kale) to 0.19 pg TEQ/g (oils and fats). A long-term dietary exposure distribution was calculated using Monte Carlo Risk Assessment software. The lower bound median exposure of the Dutch population to PCDD/Fs and dioxin-like PCBs was estimated at 0.8 pg WHO-TEQ/kgbw/d, half of which were dioxin-like PCBs. Dairy was the main source (38%) due to its high consumption. Time-trend analysis shows that the exposure to dioxins has further decreased by 35% over the past five years. This is due to lower levels of dioxin-like compounds in most of the foods, mainly influenced by lower levels in meat and milk. The use of the new TEFs gives an exposure reduction of 10% with respect to TEF(1998). Still, 4% of the Dutch population exceeds the exposure limit of 14 pg/kgbw/week as set by the EU.

  4. Infant acute leukemia and maternal exposures during pregnancy.

    PubMed

    Pombo-de-Oliveira, Maria S; Koifman, Sergio

    2006-12-01

    Infant acute leukemia (IAL) has a unique profile characterized by the high incidence of translocations involving the MLL gene located at the 11q23 region. To test the potential role of intrauterine and perinatal factors linked to the risk of IAL development, a hospital-based case-control study was conducted in different cities of Brazil. A total of 202 children (ages 0-21 months) with newly diagnosed IAL was enrolled (1999-2005), and 440 age-matched controls were selected from the same hospitals wherein IAL cases were treated. A statistically significant association between maternal use of hormones during pregnancy and IAL was observed [odds ratio (OR), 8.76; 95% confidence interval (95% CI), 2.85-26.93] in a multivariable analysis. The association of certain exposures during pregnancy (hormones, dipyrone, metronidazole, and misoprostol) and MLL gene rearrangements was tested using a case-case approach. Despite the lack of statistical significance, the magnitude of the OR for maternal exposure to dipyrone (OR, 1.45; 95% CI, 0.75-2.86), metronidazole (OR, 1.72; 95% CI, 0.64-4.58), quinolones (OR, 2.25; 95% CI, 0.70-25.70), and hormones (OR, 1.88; 95% CI, 0.50-7.01) may suggest the occurrence of interactions between such maternal exposures during pregnancy and MLL rearrangements, yielding into IAL development. The strong and statistically significant association between IAL and estrogen exposure during pregnancy observed in this study deserves further investigation to investigate its role in intrauterine leukemogenesis.

  5. Risk assessment of dietary exposure to tryptamine for the Austrian population.

    PubMed

    Wüst, Nadja; Rauscher-Gabernig, Elke; Steinwider, Johann; Bauer, Friedrich; Paulsen, Peter

    2017-03-01

    Tryptamine acts as a neuromodulator and vasoactive agent in the human body. Dose-response data on dietary tryptamine are scarce and neither a toxicological threshold value nor tolerable levels in foods have been established so far. This paper reviews dose-response characteristics and toxicological effects of tryptamine as well as tryptamine contents in food, estimates dietary exposure of Austrian consumers, and calculates risk-based maximum tolerable limits for food categories. A dose without effect of 8 mg kg(-1) body weight day(-1) was derived from literature data. Dietary exposure via fish/seafood, beer, cheese and meat products was estimated for Austrian schoolchildren, female and male consumers, based on 543 food samples analysed in Austria 2010-15 and on food consumption data from 2008. Even worst-case estimates based on very high tryptamine contents reported in the literature did not exceed 5.9 mg kg(-1) body weight day(-1), and thus were below the dose without effect. Maximum tolerable levels for food commodities were calculated for high-consumption scenarios (95th percentile of female Austrian consumers). For fresh/cooked fish, preserved fish, cheese, raw sausage, condiments, sauerkraut and fermented tofu, maximum tolerable levels were 1650, 3200, 2840, 4800, 14,120, 1740 and 2400 mg kg(-1), respectively. For beer, the maximum tolerable limit of 65 mg kg(-1) included an uncertainty factor of 10. None of the Austrian occurrence data exceeded these levels (in fact, only 3.3% of samples demonstrated measurable amounts of tryptamine), and just one report was found in the literature on a raw fish sample exceeding the respective tolerable level. In sum, dietary intake of tryptamine should not cause adverse health effects in healthy individuals. The assessment did not take into account the combined effects of simultaneously ingested biogenic amines, and increased susceptibility to tryptamine, e.g., due to reduced monoamine oxidase activity.

  6. Dental fractures on acute exposure to high altitude.

    PubMed

    Zadik, Yehuda; Einy, Shmuel; Pokroy, Russell; Bar Dayan, Yaron; Goldstein, Liav

    2006-06-01

    There is little in the literature on dental restoration breakage in the aviation environment since reports of problems in combat aviators in War World II. We report two cases of dental fractures during acute exposure to a hypobaric environment. Case 1 was a young officer who suffered an amalgam restoration breakage during a 25,000-ft decompression chamber simulation. Case 2 occurred in an experienced aviator who had a tooth cusp fracture in a molar with a defective amalgam restoration during an unpressurized helicopter flight to 18,000 ft. In both cases, after removing the defective fillings, deep secondary caries were found; both teeth were successfully restored. Because hard-tissue tooth fracture during a high-altitude flight is a rare event, few flight surgeons or dentists are familiar with this phenomenon. We recommend regular dental examinations with careful assessment of previous dental restorations in aircrew subject to decompression.

  7. Effect of acute smoke exposure on hepatic protein synthesis.

    PubMed

    Garrett, R J; Jackson, M A

    1979-05-01

    In vivo hepatic protein synthesis was monitored in female rats under control and smoke-exposed conditions. During the 15 min period after i.v. administration of [3H]proline protein synthesis was 206 +/- 35 nmol of proline per mg of DNA for sham-control animals. When animals were subjected to acute exposure to cigarette smoke, protein synthesis was inhibited and the extent of inhibition was positively correlated with the dosage of smoke (32%, 15 puffs; 66%, 60 puffs). The inhibitory effect of whole smoke on protein synthesis was unaltered by passing the smoke through either charcoal or cambridge filters. Carbon monoxide in smoke is not removed by either type of filter. At a level comparable to that in cigarette smoke carbon monoxide depressed hepatic protein synthesis to the same extent as did whole or filtered smoke.

  8. Acute health effects of accidental chlorine gas exposure

    PubMed Central

    2014-01-01

    Objectives This study was conducted to report the course of an accidental release of chlorine gas that occurred in a factory in Gumi-si, South Korea, on March 5, 2013. We describe the analysis results of 2 patients hospitalized because of chlorine-induced acute health problems, as well as the clinical features of 209 non-hospitalized patients. Methods We analyzed the medical records of the 2 hospitalized patients admitted to the hospital, as well as the medical records and self-report questionnaires of 209 non-hospitalized patients completed during outpatient treatment. Results Immediately after the exposure, the 2 hospitalized patients developed acute asthma-like symptoms such as cough and dyspnea, and showed restrictive and combined pattern ventilatory defects on the pulmonary function test. The case 1 showed asthma-like symptoms over six months and diurnal variability in peak expiratory flow rate was 56.7%. In case 2, his FEV1 after treatment (93%) increased by 25% compared to initial FEV1 (68%). Both cases were diagnosed as chlorine-induced reactive airways dysfunction syndrome (RADS) on the basis of these clinical features. The most frequent chief complaints of the 209 non-hospitalized patients were headache (22.7%), followed by eye irritation (18.2%), nausea (11.2%), and sore throat (10.8%), with asymptomatic patients accounting for 36.5%. The multiple-response analysis of individual symptom revealed headache (42.4%) to be the most frequent symptom, followed by eye irritation (30.5%), sore throat (30.0%), cough (29.6%), nausea (27.6%), and dizziness (27.3%). Conclusions The 2 patients hospitalized after exposure to chlorine gas at the leakage site showed a clinical course corresponding to RADS. All of the 209 non-hospitalized patients only complained of symptoms of the upper airways and mucous membrane irritation. PMID:25852940

  9. Probabilistic dietary exposure to ethyl carbamate from fermented foods and alcoholic beverages in the Korean population.

    PubMed

    Choi, B; Ryu, D; Kim, C-I; Lee, J-Y; Choi, A; Koh, E

    2017-09-04

    The occurrence of ethyl carbamate was investigated in fermented foods and alcoholic beverages of the Korean total diet study. The concentrations of ethyl carbamate ranged from not detected to 166.5 μg kg(-1). Dietary exposure to ethyl carbamate was estimated by the probabilistic method. Estimated intakes of ethyl carbamate from foods and alcoholic beverages were 4.12 ng kg(-1) body weight (bw) per day for average consumers and 12.37 ng kg(-1) bw/day for 95th percentile high consumers. The major foods contributing to ethyl carbamate exposure were soy sauce (63%), followed by maesilju (plum liqueur, 30%), whisky (5%), and bokbunjaju (black raspberry wine, 2%). On the basis of the benchmark dose lower confidence limit 10% (BMDL10) of 0.3 mg kg(-1) bw/day, margins of exposure were 128,000 for mean exposure and 40,000 for 95th percentile exposure. This indicates that the exposure of the Korean general population for ethyl carbamate is of low concern. However, careful vigilance should be continued for high consumers of fermented foods and alcoholic beverages.

  10. Harmonisation of food categorisation systems for dietary exposure assessments among European children.

    PubMed

    De Neve, M; Sioen, I; Boon, P E; Arganini, C; Moschandreas, J; Ruprich, J; Lafay, L; Amiano, P; Arcella, D; Azpiri, M; Busk, L; Christensen, T; D'addezio, L; Fabiansson, S; Hilbig, A; Hirvonen, T; Kersting, M; Koulouridaki, S; Liukkonen, K-H; Oltarzewski, M; Papoutsou, S; Rehurkova, I; Ribas-Barba, L; Serra-Majem, L; Tornaritis, M; Trolle, E; Van Klaveren, J D; Verger, E; Walkiewicz, A; Westerlund, A; De Henauw, S; Huybrechts, I

    2010-12-01

    Within the European project called EXPOCHI (Individual Food Consumption Data and Exposure Assessment Studies for Children), 14 different European individual food consumption databases of children were used to conduct harmonised dietary exposure assessments for lead, chromium, selenium and food colours. For this, two food categorisation systems were developed to classify the food consumption data in such a way that these could be linked to occurrence data of the considered compounds. One system served for the exposure calculations of lead, chromium and selenium. The second system was developed for the exposure assessment of food colours. The food categories defined for the lead, chromium and selenium exposure calculations were used as a basis for the food colour categorisation, with adaptations to optimise the linkage with the food colour occurrence data. With this work, an initial impetus was given to make user-friendly food categorisation systems for contaminants and food colours applicable on a pan-European level. However, a set of difficulties were encountered in creating a common food categorisation system for 14 individual food consumption databases that differ in the type and number of foods coded and in level of detail provided about the consumed foods. The work done and the problems encountered in this project can be of interest for future projects in which food consumption data will be collected on a pan-European level and used for common exposure assessments.

  11. Acute arsenic exposure treated with oral D-penicillamine

    SciTech Connect

    Watson, W.A.; Veltri, J.C.; Metcalf, T.J.

    1981-06-01

    Arsenic trioxide (As2O3) is the arsenic compound most commonly implicated in acute toxic exposures. The toxicity of As2O3 is a function of the preparation's particle size and solubility. A 16-month-old female presented at a local emergency room with a history of acute ingestion of As2O3 obtained from a commonly available pesticide. Classic gastrointestinal symptoms of arsenic toxicity were exhibited shortly after ingestion; however, aggressive decontamination followed by early chelation therapy resulted in the cessation of toxic manifestations and an uneventful recovery. Oral chelation therapy with D-penicillamine has rarely been reported as an effective agent in the treatment of arsenic poisoning. The case reported herein is further documentation that D-penicillamine is effective in increasing the mobilization of arsenic. The authors also recommend that products containing arsenic compounds should not be used where children may come in contact with them until the Environmental Protection Agency's child resistant packaging regulations become effective.

  12. Specific metabolic fingerprint of a dietary exposure to a very low dose of endosulfan.

    PubMed

    Canlet, Cécile; Tremblay-Franco, Marie; Gautier, Roselyne; Molina, Jérôme; Métais, Benjamin; Blas-Y Estrada, Florence; Gamet-Payrastre, Laurence

    2013-01-01

    Like other persistent organochlorine pesticides, endosulfan residues have been detected in foods including fruit, vegetables, and fish. The aim of our study was to assess the impact of a dietary exposure to low doses of endosulfan from foetal development until adult age on metabolic homeostasis in mice and to identify biomarkers of exposure using an (1)H-NMR-based metabonomic approach in various tissues and biofluids. We report in both genders an increase in plasma glucose as well as changes in levels of factors involved in the regulation of liver oxidative stress, confirming the prooxidant activities of this compound. Some metabolic changes were distinct in males and females. For example in plasma, a decrease in lipid LDL and choline content was only observed in female. Lactate levels in males were significantly increased. In conclusion, our results show that metabolic changes in liver could be linked to the onset of pathologies like diabetes and insulin resistance. Moreover from our results it appears that the NMR-based metabonomic approach could be useful for the characterization in plasma of a dietary exposure to low dose of pesticide in human.

  13. Relation between dietary acrylamide exposure and biomarkers of internal dose in Canadian teenagers.

    PubMed

    Brisson, Benjamin; Ayotte, Pierre; Normandin, Louise; Gaudreau, Éric; Bienvenu, Jean-François; Fennell, Timothy R; Blanchet, Carole; Phaneuf, Denise; Lapointe, Caroline; Bonvalot, Yvette; Gagné, Michelle; Courteau, Marilène; Snyder, Rodney W; Bouchard, Michèle

    2014-01-01

    Acrylamide (AA) is a probable human carcinogen found in several foods. Little information is available regarding exposure of adolescents, a subgroup potentially consuming more AA-rich foods. We investigated the relationship between dietary AA intake and levels of biomarkers of exposure (urinary metabolites and hemoglobin adducts) in 195 non-smoking teenagers of Montreal Island aged 10-17 years. Dietary habits and personal characteristics were documented by questionnaire. AA and its metabolites were quantified in 12-h urine collections by LC-MS/MS. Hemoglobin adducts from 165 blood samples were also analyzed by LC-MS/MS. Most prevalent urinary metabolites were NACP and NACP-S, with respective geometric mean concentrations of 31.2 and 14.2 μmol/mol creatinine. Geometric mean concentrations of AAVal and GAVal (hemoglobin adducts of AA and glycidamide (GA) with N-terminal valine residues) were 45.4 and 45.6 pmol/g globin, respectively. AA intake during the 2 days before urine collection was a significant predictor of NACP+NACP-S urinary concentrations (P<0.0001). AA intakes during the month before blood collection (P<0.0001) and passive smoking (P<0.05) were associated with adduct levels. Levels of hemoglobin adducts were above biomonitoring equivalent values corresponding to a 1 × 10(-4) excess cancer risk, which may indicate the need to reduce AA exposure in the population.

  14. Organic Diets Significantly Lower Children’s Dietary Exposure to Organophosphorus Pesticides

    PubMed Central

    Lu, Chensheng; Toepel, Kathryn; Irish, Rene; Fenske, Richard A.; Barr, Dana B.; Bravo, Roberto

    2006-01-01

    We used a novel study design to measure dietary organophosphorus pesticide exposure in a group of 23 elementary school-age children through urinary biomonitoring. We substituted most of children’s conventional diets with organic food items for 5 consecutive days and collected two spot daily urine samples, first-morning and before-bedtime voids, throughout the 15-day study period. We found that the median urinary concentrations of the specific metabolites for malathion and chlorpyrifos decreased to the nondetect levels immediately after the introduction of organic diets and remained nondetectable until the conventional diets were reintroduced. The median concentrations for other organophosphorus pesticide metabolites were also lower in the organic diet consumption days; however, the detection of those metabolites was not frequent enough to show any statistical significance. In conclusion, we were able to demonstrate that an organic diet provides a dramatic and immediate protective effect against exposures to organophosphorus pesticides that are commonly used in agricultural production. We also concluded that these children were most likely exposed to these organophosphorus pesticides exclusively through their diet. To our knowledge, this is the first study to employ a longitudinal design with a dietary intervention to assess children’s exposure to pesticides. It provides new and persuasive evidence of the effectiveness of this intervention. PMID:16451864

  15. Dietary Phthalate Exposure in Pregnant Women and the Impact of Consumer Practices

    PubMed Central

    Serrano, Samantha E.; Karr, Catherine J.; Seixas, Noah S.; Nguyen, Ruby H. N.; Barrett, Emily S.; Janssen, Sarah; Redmon, Bruce; Swan, Shanna H.; Sathyanarayana, Sheela

    2014-01-01

    Phthalates are ubiquitous endocrine-disrupting chemicals that are contaminants in food and contribute to significant dietary exposures. We examined associations between reported consumption of specific foods and beverages and first trimester urinary phthalate metabolite concentrations in 656 pregnant women within a multicenter cohort study, The Infant Development and Environment Study (TIDES), using multivariate regression analysis. We also examined whether reported use of ecofriendly and chemical-free products was associated with lower phthalate biomarker levels in comparison to not following such practices. Consumption of one additional serving of dairy per week was associated with decreases of 1% in the sum of di-2-ethylhexyl phthalate (DEHP) metabolite levels (95% CI: −2.0, −0.2). Further, participants who reported sometimes eating homegrown food had monoisobutyl phthalate (MiBP) levels that were 16.6% lower (95% CI: −29.5, −1.3) in comparison to participants in the rarely/never category. In contrast to rarely/never eating frozen fruits and vegetables, participants who reported sometimes following this practice had monobenzyl phthalate (MBzP) levels that were 21% higher (95% CI: 3.3, 41.7) than rarely/ever respondents. Future study on prenatal dietary phthalate exposure and the role of consumer product choices in reducing such exposure is needed. PMID:24927036

  16. Estimated dietary dioxin exposure and breast cancer risk among women from the French E3N prospective cohort.

    PubMed

    Danjou, Aurélie M N; Fervers, Béatrice; Boutron-Ruault, Marie-Christine; Philip, Thierry; Clavel-Chapelon, Françoise; Dossus, Laure

    2015-03-17

    Dioxins are environmental and persistent pollutants mostly emitted from combustion facilities (e.g. waste incinerators, metal and cement industries). Known to be endocrine disrupting chemicals, dioxins are suspected to increase breast cancer (BC) risk. Although diet is considered the primary source of dioxin exposure, no previous study has been published on dietary dioxin exposure in relation to BC risk. We aimed to assess dietary dioxin exposure among women from the E3N cohort and estimate BC risk associated with this exposure. The study included 63,830 women from the E3N cohort who completed a diet history questionnaire (DHQ) in 1993 and were followed until 2008. Dietary dioxin exposure was estimated by combining consumption data from the E3N DHQ and food dioxin contamination data from a French national monitoring program. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated by Cox models adjusted for BC risk factors. Mean dietary dioxin exposure was estimated at 1.3 ± 0.4 pg/kg body weight (BW)/day. A 0.4 pg/kg BW/d increase in dioxin intake was not associated with overall BC risk (HR = 1.00; 95% CI: 0.96, 1.05). A significant decrease in risk of estrogen receptor negative (ER-)/progesterone receptor negative (PR-) tumors was observed among post-menopausal women in the upper quartile of estimated dioxin intake (HR for Q4 vs. Q1: 0.65; 95% CI: 0.45, 0.96; P for trend across quartiles = 0.0463). Overall, no association between estimated dietary dioxin exposure and BC risk was found among E3N women. Further studies should include both dietary and environmental exposures to determine whether low-dose dioxin exposure is associated with BC risk.

  17. Dietary exposure to aflatoxin B1, ochratoxin A and fuminisins of adults in Lao Cai province, Viet Nam: A total dietary study approach.

    PubMed

    Huong, Bui Thi Mai; Tuyen, Le Danh; Tuan, Do Huu; Brimer, Leon; Dalsgaard, Anders

    2016-12-01

    Aflatoxins, fumonisins and ochratoxin A that contaminate various agricultural commodities are considered of significant toxicity and potent human carcinogens. This study took a total dietary study approach and estimated the dietary exposure of these mycotoxins for adults living in Lao Cai province, Vietnam. A total of 42 composite food samples representing 1134 individual food samples were prepared according to normal household practices and analysed for the three mycotoxins. Results showed that the dietary exposure to aflatoxin B1 (39.4 ng/kg bw/day) and ochratoxin A (18.7 ng/kg bw/day) were much higher than recommended provisional tolerable daily intake (PTDI) values mainly due to contaminated cereals and meat. The exposure to total fumonisins (1400 ng/kg bw/day) was typically lower than the PTDI value (2000 ng/kg bw/day). The estimated risk of liver cancer associated with exposure to aflatoxin B1 was 2.7 cases/100,000 person/year. Margin of exposure (MOE) of renal cancer linked to ochratoxin A and liver cancer associated with fumonisins were 1124 and 1954, respectively indicating risk levels of public health concern. Further studies are needed to evaluate the efficiency of technical solutions which could reduce mycotoxin contamination as well as to determine the health effects of the co-exposure to different types of mycotoxins.

  18. Nephropathy in dietary hyperoxaluria: A potentially preventable acute or chronic kidney disease

    PubMed Central

    Glew, Robert H; Sun, Yijuan; Horowitz, Bruce L; Konstantinov, Konstantin N; Barry, Marc; Fair, Joanna R; Massie, Larry; Tzamaloukas, Antonios H

    2014-01-01

    Hyperoxaluria can cause not only nephrolithiasis and nephrocalcinosis, but also renal parenchymal disease histologically characterized by deposition of calcium oxalate crystals throughout the renal parenchyma, profound tubular damage and interstitial inflammation and fibrosis. Hyperoxaluric nephropathy presents clinically as acute or chronic renal failure that may progress to end-stage renal disease (ESRD). This sequence of events, well recognized in the past in primary and enteric hyperoxalurias, has also been documented in a few cases of dietary hyperoxaluria. Estimates of oxalate intake in patients with chronic dietary hyperoxaluria who developed chronic kidney disease or ESRD were comparable to the reported average oxalate content of the diets of certain populations worldwide, thus raising the question whether dietary hyperoxaluria is a primary cause of ESRD in these regions. Studies addressing this question have the potential of improving population health and should be undertaken, alongside ongoing studies which are yielding fresh insights into the mechanisms of intestinal absorption and renal excretion of oxalate, and into the mechanisms of development of oxalate-induced renal parenchymal disease. Novel preventive and therapeutic strategies for treating all types of hyperoxaluria are expected to develop from these studies. PMID:25374807

  19. A META-ANALYSIS OF CHILDREN'S HAND-TO-MOUTH FREQUENCY DATA FOR ESTIMATING NON-DIETARY INGESTION EXPOSURE

    EPA Science Inventory

    Because of their mouthing behaviors, children have a higher potential for exposure to available chemicals through the non-dietary ingestion route; thus, frequency of hand-to-mouth activity is an important variable for exposure assessments. Such data are limited and difficult to ...

  20. Unexpected results in a randomized dietary trial to reduce phthalate and bisphenol A exposures.

    PubMed

    Sathyanarayana, Sheela; Alcedo, Garry; Saelens, Brian E; Zhou, Chuan; Dills, Russell L; Yu, Jianbo; Lanphear, Bruce

    2013-07-01

    Diet is a primary source of exposure for high-molecular-weight phthalates and bisphenol A (BPA), but little is known about the efficacy of various interventions to reduce exposures. We conducted a randomized trial with 10 families to test the efficacy of a 5-day complete dietary replacement (Arm 1; n=21) versus written recommendations to reduce phthalate and BPA exposures (Arm 2; n=19). We measured phthalate and BPA concentrations in urine samples at baseline, intervention, and post-intervention periods. We used Wilcoxon paired signed-rank tests to assess change in concentrations across time and multi-level mixed effects regression models to assess differences between Arms 1 and 2. Urinary di(2-ethylhexyl) phthalate (DEHP) metabolite concentrations increased unexpectedly from a median of 283.7 nmol/g at baseline to 7027.5 nmol/g during the intervention (P<0.0001) among Arm 1 participants, and no significant changes were observed for Arm 2 participants. We observed a statistically significant increase in total BPA concentration between baseline and intervention periods in Arm 1 but no significant changes in Arm 2. Arm 1 food ingredient testing for DEHP revealed concentrations of 21,400 ng/g in ground coriander and 673 ng/g in milk. Food contamination with DEHP led to unexpected increases in urinary phthalate concentrations in a trial intended to minimize exposure. In the absence of regulation to reduce phthalate and BPA concentrations in food production, it may be difficult to develop effective interventions that are feasible in the general population. An estimate of DEHP daily intake for children in the dietary replacement Arm was above the US Environmental Protection Agency oral reference dose and the European Food Safety Authority's tolerable daily intake, suggesting that food contamination can be a major source of DEHP exposure.

  1. Sildenafil does not Improve Exercise Capacity under Acute Hypoxia Exposure.

    PubMed

    Toro-Salinas, A H; Fort, N; Torrella, J R; Pagès, T; Javierre, C; Viscor, G

    2016-09-01

    The increase in pulmonary arterial pressure (PAP) due to hypoxic pulmonary vasoconstriction (HPV) could be a limiting factor for physical performance during hypoxic exposure. Sildenafil has been shown to reduce PAP in situations of moderate or severe hypoxia, and consequently its role as an ergogenic aid and even a possible doping substance must be considered. We performed a double-blind crossover study to determine the effects of sildenafil on cardiovascular, respiratory and metabolic parameters in normoxia and during acute exposure to hypobaric hypoxia (4 000 m) at rest and during maximal and submaximal (60% VO2 max) exercise tests. One hour before testing started, sildenafil (100 mg) or a placebo was orally administered to 11 volunteers. In normoxic conditions, sildenafil did not affect performance. Similarly, no significant differences were found in cardiovascular and respiratory parameters in hypoxic conditions at rest or during exercise. The use of sildenafil to improve physical performance in non-acclimatized subjects is not supported by our data. © Georg Thieme Verlag KG Stuttgart · New York.

  2. Acute skin lesions due to localized ``hot particle`` radiation exposures

    SciTech Connect

    Baum, J.W.; Carsten, A.L.; Kaurin, D.G.L.; Schaefer, C.W.

    1996-06-01

    Purpose of the studies was to determine incidence and severity of lesions resulting from localized deposition of dose to the skin from small (<0.5 mm) discrete radioactive particles. Hanford mini-swine were exposed to localized doses from 0.2 to over 600 Gy (averaged over 1 cm{sup 2} at 70{mu}m depth) from isotopes having max beta particle energies from about 0.3-3 MeV. Incidence of erythema and scabs (indicating ulceration) were scored routinely for up to 71 days post-irradiation. Responses followed normal probability distributions, and thus, no true threshold could be defined. Ten and 50% incidence rates were deduced using probit analyses. Lowest dose producing 10% incidence was about 1 Gy for exposures to Yb-175 (0.5 MeV max energy) beta particles. Severity of lesions was estimated using diameters and persistence. From preliminary considerations of probability of induction, size, and persistence of acute lesions, a special limit for hot particle exposures in the range of 5-50 Gy may be reasonable, with an action level between about 1 Gy and the limit.

  3. Predictors of individual differences in acute response to ozone exposure

    SciTech Connect

    McDonnell, W.F.; Muller, K.E.; Bromberg, P.A.; Shy, C.M. )

    1993-04-01

    The purpose of this study was to identify personal characteristics that predict individual differences in acute FEV1 response to ozone exposure. Response and predictor data were collected on 290 white male volunteers 18 to 32 yr of age who were each exposed to one of six concentrations of ozone between 0.0 and 0.40 part per million. The sample was divided into an exploratory sample of 96 and a confirmatory sample of 194 subjects. Exploratory analysis indicated that ozone, age, and several other variables explained a significant proportion of the variance in response. In the confirmatory sample, only age and ozone concentration predicted FEV1 decrement. For the combined sample ozone explained 31% of the variance, with age accounting for an additional 4%. The model predicted a decreasing response with increasing age for all nonzero ozone concentrations. For exposure to 0.40 ppm, the model predicts decrements in FEV1 of 1.07 and 0.47 L for 18- and 30-yr-old subjects, respectively. We concluded that for white male subjects age was a significant predictor of response, with older subjects being less responsive to ozone. Furthermore, we demonstrated that exploratory analysis without control of type I statistical error rates may result in apparent findings that cannot be replicated.

  4. Acute acid exposure increases rabbit esophageal cell proliferation.

    PubMed

    Carpizo, D R; Reaka, A J; Glaws, W R; Pooley, N; Schmidt, L; Halline, A G; Goldstein, J L; Layden, T J

    1998-02-01

    In the present study we examined whether an acute infusion of HCl into the esophagus of rabbits would cause an increase in esophageal cellular proliferation independent of morphologic evidence of cell injury. To examine this question, the distal two thirds of the rabbit esophagus was infused for 1 hour with either 40 mmol/L HCl or NSS (control), and cellular proliferation was studied 24 and 48 hours later by using bromodeoxyuridine (BrDu) to label the nuclei of dividing cells and ornithine decarboxylase (ODC) enzyme activity as a biochemical index of cell division. Although there was no gross or microscopic evidence of cell necrosis or mucosal inflammation 24 hours after H+ infusion, BrDu labeling of basal cell nuclei was significantly greater 24 hours after H+ infusion (31%+/-6%) as compared with that in control animals infused with NSS (15%+/-4%). This increase in labeling index was paralleled by a threefold greater ODC enzyme activity at 24 hours with H+ infusion. Rete pegs were infrequent in control tissues (4+/-4 rete pegs per 100 microm of esophageal length) or in animals examined 24 hours after acid exposure (4+/-2 rete pegs per 100 microm). However, rete pegs were very prominent 48 hours after acid infusion (22+/-6 rete pegs per 100 microm). A short exposure to acid can cause a significant increase in mucosal proliferation independent of injury, suggesting that esophageal cell acidification either directly or indirectly acts as a tissue mitogen.

  5. Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults.

    PubMed

    Casey, Darren P; Treichler, David P; Ganger, Charles T; Schneider, Aaron C; Ueda, Kenichi

    2015-01-15

    We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min(-1)·100 mmHg(-1)) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P < 0.001). During the control condition, the compensatory vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P < 0.001). Following BR consumption, compensatory vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P < 0.01). Our data suggest that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise in older but not young adults. Copyright © 2015 the American Physiological Society.

  6. Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men

    PubMed Central

    Kim, Jin-Kwang; Moore, David J.; Maurer, David G.; Kim-Shapiro, Daniel B.; Basu, Swati; Flanagan, Michael P.; Skulas-Ray, Ann C.; Kris-Etherton, Penny; Proctor, David N.

    2014-01-01

    Despite the popularity of dietary nitrate supplementation and the growing evidence base of its potential ergogenic and vascular health benefits, there is no direct information about its effects on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery, during graded handgrip exercise in healthy young men. In a randomized, double-blind, placebo-controlled crossover study, 12 young (22 ± 2 years) healthy men consumed a beetroot juice (140 mL Beet-It Sport, James White Juice Company) that provided 12.9 mmol (0.8 g) of nitrate or placebo (nitrate-depleted Beet-It Sport) on 2 study visits. At 3 h postconsumption, brachial artery diameter, flow, and blood velocity were measured (Doppler ultrasound) at rest and during 6 exercise intensities. Nitrate supplementation raised plasma nitrate (19.5-fold) and nitrite (1.6-fold) concentrations, and lowered resting arterial pulse wave velocity (PWV) versus placebo (all p < 0.05) indicating absorption, conversion, and a biological effect of this supplement. The supplement-associated lowering of PWV was also negatively correlated with plasma nitrite (r = -0.72, p = 0.0127). Despite these systemic effects, nitrate supplementation had no effect on brachial artery diameter, flow, or shear rates at rest (all p ≥ 0.28) or during any exercise workload (all p ≥ 0.18). These findings suggest that acute dietary nitrate supplementation favorably modifies arterial PWV, but does not augment blood flow or brachial artery vasodilation during non-fatiguing forearm exercise in healthy young men. PMID:25536008

  7. Acute dietary nitrate supplementation does not augment submaximal forearm exercise hyperemia in healthy young men.

    PubMed

    Kim, Jin-Kwang; Moore, David J; Maurer, David G; Kim-Shapiro, Daniel B; Basu, Swati; Flanagan, Michael P; Skulas-Ray, Ann C; Kris-Etherton, Penny; Proctor, David N

    2015-02-01

    Despite the popularity of dietary nitrate supplementation and the growing evidence base of its potential ergogenic and vascular health benefits, there is no direct information about its effects on exercising limb blood flow in humans. We hypothesized that acute dietary nitrate supplementation from beetroot juice would augment the increases in forearm blood flow, as well as the progressive dilation of the brachial artery, during graded handgrip exercise in healthy young men. In a randomized, double-blind, placebo-controlled crossover study, 12 young (22 ± 2 years) healthy men consumed a beetroot juice (140 mL Beet-It Sport, James White Juice Company) that provided 12.9 mmol (0.8 g) of nitrate or placebo (nitrate-depleted Beet-It Sport) on 2 study visits. At 3 h postconsumption, brachial artery diameter, flow, and blood velocity were measured (Doppler ultrasound) at rest and during 6 exercise intensities. Nitrate supplementation raised plasma nitrate (19.5-fold) and nitrite (1.6-fold) concentrations, and lowered resting arterial pulse wave velocity (PWV) versus placebo (all p < 0.05), indicating absorption, conversion, and a biological effect of this supplement. The supplement-associated lowering of PWV was also negatively correlated with plasma nitrite (r = -0.72, p = 0.0127). Despite these systemic effects, nitrate supplementation had no effect on brachial artery diameter, flow, or shear rates at rest (all p ≥ 0.28) or during any exercise workload (all p ≥ 0.18). These findings suggest that acute dietary nitrate supplementation favorably modifies arterial PWV, but does not augment blood flow or brachial artery vasodilation during nonfatiguing forearm exercise in healthy young men.

  8. Acute dietary nitrate supplementation enhances compensatory vasodilation during hypoxic exercise in older adults

    PubMed Central

    Treichler, David P.; Ganger, Charles T.; Schneider, Aaron C.; Ueda, Kenichi

    2014-01-01

    We have previously demonstrated that aging reduces the compensatory vasodilator response during hypoxic exercise due to blunted nitric oxide (NO) signaling. Recent evidence suggests that NO bioavailability can be augmented by dietary nitrate through the nitrate-nitrite pathway. Thus we tested the hypothesis that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise, particularly in older adults. Thirteen young (25 ± 1 yr) and 12 older (64 ± 2 yr) adults performed rhythmic forearm exercise at 20% of maximum voluntary contraction during normoxia and hypoxia (∼80% O2 saturation); both before (control) and 3 h after beetroot juice (BR) consumption. Forearm vascular conductance (FVC; ml·min−1·100 mmHg−1) was calculated from forearm blood flow (ml/min) and blood pressure (mmHg). Compensatory vasodilation was defined as the relative increase in FVC due to hypoxic exercise (i.e., % increase compared with respective normoxic exercise trial). Plasma nitrite was determined from venous blood samples obtained before the control trials and each of the exercise trials (normoxia and hypoxia) after BR. Consumption of BR increased plasma nitrite in both young and older adults (P < 0.001). During the control condition, the compensatory vasodilator response to hypoxic exercise was attenuated in older compared with young adults (3.8 ± 1.7% vs. 14.2 ± 1.2%, P < 0.001). Following BR consumption, compensatory vasodilation did not change in young (13.7 ± 3.3%, P = 0.81) adults but was substantially augmented in older adults (11.4 ± 2.1%, P < 0.01). Our data suggest that acute dietary nitrate supplementation increases the compensatory vasodilator response to hypoxic exercise in older but not young adults. PMID:25414241

  9. Dietary exposure of mink to carp from Saginaw Bay. 3. Characterization of dietary exposure to planar halogenated hydrocarbons, dioxin equivalents, and biomagnification

    USGS Publications Warehouse

    Tillitt, Donald E.; Gale, Robert W.; Meadows, John C.; Zajicek, James L.; Peterman, Paul H.; Heaton, Silvia N.; Jones, Paul D.; Bursian, Steven J.; Kubiak, Timothy J.; Giesy, John P.; Aulerich, Richard J.

    1995-01-01

    Mink are known to be very sensitive to the toxic effects of planar polychlorinated biphenyls (pPCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), collectively known as planar halogenated hydrocarbons (PHHs). Previously, we reported the reproductive effects in mink fed a diet containing 10, 20, or 40% fish taken from Saginaw Bay, Lake Huron. The present study reports the chemical characterization of the diets and the adult mink livers, along with a comparison of an additive model of toxicity with the results of the H4IIE bioassay on these samples. The assessment of dietary or tissue-based exposure of the mink to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds revealed that TCDD equivalents of the PHH mixtures largely followed an additive model of toxicity as compared with the H4IIE bioassay. Consistent dietary and liver tissue-based threshold concentrations for reproductive toxicity in mink were determined regardless of whether PHHs were quantified as TEQs (additive toxicity) or TCDD-EQs (H4IIE bioassay). Significant reproductive effects were observed in the lowest treatment group (10% fish or 19.4 pg of H4IIE bioassay-derived TCDD-EQs/g). Consumption-normalized mink liver biomagnification factors (BMFs) were 6.4−74.2 for PCDDs, <1−75.8 for PCDFs, <1−15.9 for PCBs, and in general, increased with degree of chlorination within each class. Based on TEQs or TCDD-EQ, this study confirms that mink are among the most, if not the most, sensitive mammalian species to the reproductive toxicity of TCDD and related compounds.

  10. Biomarkers of acute respiratory allergen exposure: Screening for sensitization potential

    SciTech Connect

    Pucheu-Haston, Cherie M.; Copeland, Lisa B.; Vallanat, Beena; Boykin, Elizabeth; Ward, Marsha D.W.

    2010-04-15

    Effective hazard screening will require the development of high-throughput or in vitro assays for the identification of potential sensitizers. The goal of this preliminary study was to identify potential biomarkers that differentiate the response to allergens vs non-allergens following an acute exposure in naive individuals. Female BALB/c mice received a single intratracheal aspiration exposure to Metarhizium anisopliae crude antigen (MACA) or bovine serum albumin (BSA) in Hank's Balanced Salt Solution (HBSS) or HBSS alone. Mice were terminated after 1, 3, 6, 12, 18 and 24 h. Bronchoalveolar lavage fluid (BALF) was evaluated to determine total and differential cellularity, total protein concentration and LDH activity. RNA was isolated from lung tissue for microarray analysis and qRT-PCR. MACA administration induced a rapid increase in BALF neutrophils, lymphocytes, eosinophils and total protein compared to BSA or HBSS. Microarray analysis demonstrated differential expression of genes involved in cytokine production, signaling, inflammatory cell recruitment, adhesion and activation in 3 and 12 h MACA-treated samples compared to BSA or HBSS. Further analyses allowed identification of approx 100 candidate biomarker genes. Eleven genes were selected for further assessment by qRT-PCR. Of these, 6 demonstrated persistently increased expression (Ccl17, Ccl22, Ccl7, Cxcl10, Cxcl2, Saa1), while C3ar1 increased from 6-24 h. In conclusion, a single respiratory exposure of mice to an allergenic mold extract induces an inflammatory response which is distinct in phenotype and gene transcription from the response to a control protein. Further validation of these biomarkers with additional allergens and irritants is needed. These biomarkers may facilitate improvements in screening methods.

  11. Flight Performance During Exposure to Acute Hypobaric Hypoxia.

    PubMed

    Steinman, Yuval; van den Oord, Marieke H A H; Frings-Dresen, Monique H W; Sluiter, Judith K

    2017-08-01

    The purpose of the present study was to examine the influence of hypobaric hypoxia (HH) on a pilot's flight performance during exposure to simulated altitudes of 91, 3048, and 4572 m (300, 10,000, and 15,000 ft) and to monitor the pilot's physiological reactions. In a single-blinded counter-balanced design, 12 male pilots were exposed to HH while flying in a flight simulator that had been placed in a hypobaric chamber. Flight performance of the pilots, pilot's alertness level, Spo2, heart rate (HR), minute ventilation (VE), and breathing frequency (BF) were measured. A significant difference was found in Flight Profile Accuracy (FPA) between the three altitudes. Post hoc analysis showed no significant difference in performance between 91 m and 3048 m. A trend was observed at 4572 m, suggesting a decrease in flight performance at that altitude. Significantly lower alertness levels were observed at the start of the flight at 4572 m compared to 91 m, and at the end of the flight at 4572 m compared to the start at that altitude. Spo2 and BF decreased, and HR increased significantly with altitude. The present study did not provide decisive evidence for a decrease in flight performance during exposure to simulated altitudes of 3048 and 4572 m. However, large interindividual variation in pilots' flight performance combined with a gradual decrease in alertness levels observed in the present study puts into question the ability of pilots to safely fly an aircraft while exposed to these altitudes without supplemental oxygen.Steinman Y, van den Oord MHAH, Frings-Dresen MHW, Sluiter JK. Flight performance during exposure to acute hypobaric hypoxia. Aerosp Med Hum Perform. 2017; 88(8):760-767.

  12. Dietary exposure to short-chain chlorinated paraffins has increased in Beijing, China.

    PubMed

    Harada, Kouji H; Takasuga, Takumi; Hitomi, Toshiaki; Wang, Peiyu; Matsukami, Hidenori; Koizumi, Akio

    2011-08-15

    Short-chain chlorinated paraffins (SCCPs) persist in the environment and bioaccumulate in biota and are under review by the Stockholm Convention on persistent organic pollutants. SCCP levels were measured semiquantitatively in pooled 24 h food composite samples from Chinese (n = 10), Korean (n = 10), and Japanese (n = 40) adults in the 1990 s and 2007-2009. In Japan, SCCPs were detected in 14 of 20 pooled samples in the 1990 s and 13 of 20 pooled samples in 2009. Between these two time points, the geometric mean (GM) of the dietary intake of total SCCPs per body weight was comparable in Japan (54 ng kg-bw(-1) day(-1) in the 1990 s and 54 ng kg-bw(-1) day(-1) in the 2000s). In Beijing, SCCP levels were elevated by 2 orders of magnitude from 1993 to 2009 (GM: 620 ng kg-bw(-1) day(-1) in 2009). The 95th percentile estimate of the dietary intake was 1200 ng kg-bw(-1) day(-1) (>1% of tolerable daily intake). In Seoul, no samples in 1994 contained detectable SCCP levels and only one sample in 2007 showed trace levels of SCCPs. Preliminary evidence on the significant increase in SCCP exposure in Beijing in 2009 warrants urgent investigations to refine dietary intake estimates by targeting food types and source identification.

  13. Comparison of aquatic and dietary exposure of heavy metals Cd, Cu, and Zn to benthic ostracod Heterocypris incongruens.

    PubMed

    Sevilla, Janice Beltran; Nakajima, Fumiyuki; Kasuga, Ikuro

    2014-07-01

    The benthic ostracod Heterocypris incongruens is becoming an important tool for the ecotoxicological assessment of contaminated sediments. However, no study has yet explored solid-phase (dietary) exposure to ostracod. The present study examined the effects of metals on H. incongruens through aquatic and dietary exposures. The algal food Chlorella vulgaris was exposed to different concentrations of cadmium (Cd), copper (Cu), and zinc (Zn), and subcellular distributions of these metals in algal cells were determined. Parallel experiments were also performed to determine the toxic effects of dissolved metals on ostracod through aqueous exposure. Significant toxic effects on mortality were observed when ostracod were fed with Cd-contaminated (47-100%) and Cu-contaminated algae (55-100%). With increasing accumulated Zn in the algal cell, ostracod mortality also increased (20-83%). Aquatic exposure of ostracod to different concentrations of dissolved Cd (3.2-339 µg Cd/L) and Cu (260-2600 µg Cu/L) resulted in high observed mortalities (57-100% and 95-100%, respectively). Based on the results of aqueous and dietary exposure tests, it can be concluded that both exposure routes are important in evaluating the toxic effect of Cd on ostracod. Similar results were observed in tests using other metals (i.e., using Cu and Zn), thus emphasizing the importance of considering not only aquatic but also dietary exposure routes when evaluating metal toxicity to ostracod.

  14. Considerations when using longitudinal cohort studies to assess dietary exposure to inorganic arsenic and chronic health outcomes.

    PubMed

    Scrafford, Carolyn G; Barraj, Leila M; Tsuji, Joyce S

    2016-07-01

    Dietary arsenic exposure and chronic health outcomes are of interest, due in part to increased awareness and data available on inorganic arsenic levels in some foods. Recent concerns regarding levels of inorganic arsenic, the primary form of arsenic of human health concern, in foods are based on extrapolation from adverse health effects observed at high levels of inorganic arsenic exposure; the potential for the occurrence of these health effects from lower levels of dietary inorganic arsenic exposure has not been established. In this review, longitudinal cohort studies are evaluated for their utility in estimating dietary inorganic arsenic exposure and quantifying statistically reliable associations with health outcomes. The primary limiting factor in longitudinal studies is incomplete data on inorganic arsenic levels in foods combined with the aggregation of consumption of foods with varying arsenic levels into a single category, resulting in exposure misclassification. Longitudinal cohort studies could provide some evidence to evaluate associations of dietary patterns related to inorganic arsenic exposure with risk of arsenic-related diseases. However, currently available data from longitudinal cohort studies limit causal analyses regarding the association between inorganic arsenic exposure and health outcomes. Any conclusions should therefore be viewed with knowledge of the analytical and methodological limitations.

  15. Injury to skeletal muscle of mice following acute and sub-acute pregabalin exposure

    PubMed Central

    Moshiri, Mohammad; Moallem, Seyed Adel; Attaranzadeh, Armin; Saberi, Zahra; Etemad, Leila

    2017-01-01

    Objective(s): Pregabalin (PGB) is a new antiepileptic drug that has received FDA approval for patient who suffers from central neuropathic pain, partial seizures, generalized anxiety disorder, fibromyalgia and sleep disorders. This study was undertaken to evaluate the possible adverse effects of PGB on the muscular system of mice. Materials and Methods: To evaluate the effect of PGB on skeletal muscle, the animals were exposed to a single dose of 1, 2 or 5 g /kg or daily doses of 20, 40 or 80 mg/kg for 21 days, intraperitoneally (IP). Twaenty-four hr after the last drug administration, all animals were sacrificed. The level of fast-twitch skeletal muscle troponin I and CK-MM activity were evaluated in blood as an indicator of muscle injury. Skeletal muscle pathological findings were also reported as scores ranging from 1 to 3 based on the observed lesion. Results: In the acute and sub-acute toxicity assay IP injection of PGB significantly increased the activity and levels of CK-MM and fsTnI compared to the control group. Sub-acute exposure to PGB caused damages that include muscle atrophy, infiltration of inflammatory cells and cell degeneration. Conclusion: PGB administration especially in long term care causes muscle atrophy with infiltration of inflammatory cells and cell degeneration. The fsTnI and CK-MM are reliable markers in PGB-related muscle injury. The exact mechanisms behind the muscular damage are unclear and necessitate further investigations. PMID:28392896

  16. High Dietary Iron and Radiation Exposure Increase Biomarkers of Oxidative Stress in Blood and Liver of Rats

    NASA Technical Reports Server (NTRS)

    Morgan, Jennifer L. L.; Theriot, Corey A.; Wu, Honglu; Smith, Scott M.; Zwart, Sara R.

    2012-01-01

    Radiation exposure and increased iron (Fe) status independently cause oxidative damage that can result in protein, lipid, and DNA oxidation. During space flight astronauts are exposed to both increased radiation and increased Fe stores. Increased body Fe results from a decrease in red blood cell mass and the typically high Fe content of the food system. In this study we investigated the combined effects of radiation exposure (0.375 Gy of Cs-137 every other day for 16 days for a total of 3 Gy) and high dietary Fe (650 mg Fe/kg diet compared to 45 mg Fe/kg for controls) in Sprague-Dawley rats (n=8/group). Liver and serum Fe were significantly increased in the high dietary Fe groups. Likewise, radiation treatment increased serum ferritin and Fe concentrations. These data indicate that total body Fe stores increase with both radiation exposure and excess dietary Fe. Hematocrit decreased in the group exposed to radiation, providing a possible mechanism for the shift in Fe indices after radiation exposure. Markers of oxidative stress were also affected by both radiation and high dietary Fe, evidenced by increased liver glutathione peroxidase (GPX) and serum catalase as well as decreased serum GPX. We thus found preliminary indications of synergistic effects of radiation exposure and increased dietary Fe, warranting further study. This study was funded by the NASA Human Research Project.

  17. Effects of chronic exposure to dietary selenomethionine on the physiological stress response in juvenile white sturgeon (Acipenser transmontanus).

    PubMed

    Patterson, Sarah; Zee, Jenna; Wiseman, Steve; Hecker, Markus

    2017-05-01

    dose WS. Exposure to an acute handling stressor elicited a typical cortisol response, but the magnitude of the response appeared to be significantly lower than those typically observed in teleosts. SeMeth also did not appear to modulate the cortisol response to a secondary stressor. However, WS exposed to 22.4μg Se/g dm and sampled 2h post-stressor, had significantly higher concentrations of muscle glycogen compared to controls, indicating effects on their ability to utilize muscle glycogen for energy. Overall, the results indicate that chronic exposure to dietary SeMeth concentrations >22.4μg/g can affect cortisol dynamics and mobilization of energy substrates in juvenile WS. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Adolescent Dietary Vitamin D and Sun Exposure in Relation to Benign Breast Disease

    PubMed Central

    Boeke, Caroline E.; Tamimi, Rulla M.; Berkey, Catherine S.; Colditz, Graham A.; Giovannucci, Edward; Malspeis, Susan; Willett, Walter C.; Frazier, A. Lindsay

    2015-01-01

    Purpose Vitamin D may reduce cell proliferation and tumor growth in breast tissue, and exposure may be most important during adolescence when breast tissue is developing. In the Nurses’ Health Study II, higher recalled adolescent vitamin D intake was associated with a lower risk of benign breast disease (BBD). Our study aim was to assess adolescent vitamin D exposure in relation to BBD in young women. Methods Vitamin D was assessed in 6,593 adolescent girls (9 to 15 years of age at baseline) in the prospective Growing Up Today Study cohort using the mean energy-adjusted intakes from food frequency questionnaires in 1996, 1997, and 1998. In 1999, 5286 girls reported skin color, sunscreen use, tanning bed use, and number of sunburns in the past year, and we used state of residence to assess low vs. high ultraviolet (UV) index. Biopsy-confirmed BBD was reported on questionnaires in 2005, 2007, and 2010 (n=122). Results Dietary vitamin D, tanning behaviors, and other sun exposure variables were not significantly associated with BBD in logistic regression models adjusted for age, family history of breast cancer or BBD, age at menarche, nulliparity, alcohol intake, body mass index, and physical activity. The relative risk for the top (>467 IU/day) vs. bottom (<243 IU/day) quartile of vitamin D intake was 0.76 (95% CI: 0.47, 1.23). Conclusions Sun exposure was not significantly associated with BBD in this prospective cohort study. However, a suggestive inverse association between dietary vitamin D and BBD was observed that merits further study. PMID:26084210

  19. Food Packaging and Bisphenol A and Bis(2-Ethyhexyl) Phthalate Exposure: Findings from a Dietary Intervention

    PubMed Central

    Gray, Janet M.; Engel, Connie L.; Rawsthorne, Teresa W.; Dodson, Robin E.; Ackerman, Janet M.; Rizzo, Jeanne; Nudelman, Janet L.; Brody, Julia Green

    2011-01-01

    Background: Bisphenol A (BPA) and bis(2-ethylhexyl) phthalate (DEHP) are high-production-volume chemicals used in plastics and resins for food packaging. They have been associated with endocrine disruption in animals and in some human studies. Human exposure sources have been estimated, but the relative contribution of dietary exposure to total intake has not been studied empirically. Objectives: To evaluate the contribution of food packaging to exposure, we measured urinary BPA and phthalate metabolites before, during, and after a “fresh foods” dietary intervention. Methods: We selected 20 participants in five families based on self-reported use of canned and packaged foods. Participants ate their usual diet, followed by 3 days of “fresh foods” that were not canned or packaged in plastic, and then returned to their usual diet. We collected evening urine samples over 8 days in January 2010 and composited them into preintervention, during intervention, and postintervention samples. We used mixed-effects models for repeated measures and Wilcoxon signed-rank tests to assess change in urinary levels across time. Results: Urine levels of BPA and DEHP metabolites decreased significantly during the fresh foods intervention [e.g., BPA geometric mean (GM), 3.7 ng/mL preintervention vs. 1.2 ng/mL during intervention; mono-(2-ethyl-5-hydroxy hexyl) phthalate GM, 57 ng/mL vs. 25 ng/mL]. The intervention reduced GM concentrations of BPA by 66% and DEHP metabolites by 53–56%. Maxima were reduced by 76% for BPA and 93–96% for DEHP metabolites. Conclusions: BPA and DEHP exposures were substantially reduced when participants’ diets were restricted to food with limited packaging. PMID:21450549

  20. Adolescent dietary vitamin D and sun exposure in relation to benign breast disease.

    PubMed

    Boeke, Caroline E; Tamimi, Rulla M; Berkey, Catherine S; Colditz, Graham A; Giovannucci, Edward; Malspeis, Susan; Willett, Walter C; Frazier, A Lindsay

    2015-08-01

    Vitamin D may reduce cell proliferation and tumor growth in breast tissue, and exposure may be most important during adolescence when breast tissue is developing. In the Nurses' Health Study II, higher recalled adolescent vitamin D intake was associated with a lower risk of benign breast disease (BBD). Our study aimed to assess adolescent vitamin D exposure in relation to BBD in young women. Vitamin D was assessed in 6,593 adolescent girls (9-15 years of age at baseline) in the prospective Growing Up Today Study cohort using the mean energy-adjusted intakes from food frequency questionnaires in 1996, 1997, and 1998. In 1999, 5,286 girls reported skin color, sunscreen use, tanning bed use, and number of sunburns in the past year, and we used state of residence to assess low versus high ultraviolet index. Biopsy-confirmed BBD was reported on questionnaires in 2005, 2007, and 2010 (n = 122). Dietary vitamin D, tanning behaviors, and other sun exposure variables were not significantly associated with BBD in logistic regression models adjusted for age, family history of breast cancer or BBD, age at menarche, nulliparity, alcohol intake, body mass index, and physical activity. The relative risk for the top (>467 IU/day) versus bottom (<243 IU/day) quartile of vitamin D intake was 0.76 (95 % CI 0.47, 1.23). Sun exposure was not significantly associated with BBD in this prospective cohort. However, a suggestive inverse association between dietary vitamin D and BBD was observed that merits further study.

  1. Dietary exposure estimation of benzo[a]pyrene and cancer risk assessment.

    PubMed

    Lee, Byung Mu; Shim, Geun Ae

    2007-08-01

    Dietary benzo[a]pyrene (BaP) levels were analyzed by high-performance liquid chromatography with fluorescence detection (HPLC-FLD) in various foods (e.g., snack, potato chip, bread, vegetable oil, meat, cereal, etc.) to estimate dietary intake levels of BaP for the assessment of BaP related-cancer risk in Koreans. Higher levels of BaP were detected in fried chicken (5.25-5.55 BaP microg/kg) and smoked dried beef (5.47 microg/kg) compared to relatively lower levels measured in sesame oil (0.36 microg/kg) and peanut (0.44 microg/kg). The BaP levels in nonmeat items were generally low in detection, but certain potato chip products showed levels up to 4.06 BaP microg/kg. In terms of chronic daily intake of BaP, fried chicken was shown to be the highest (70.09 ng/person/d) and perilla oil was the lowest (0.05 ng/person/d). The total daily intake of BaP due to the consumption of various food items investigated was estimated to be 124.55 ng/person/d, based on daily food consumption and the contaminant level of BaP. The dietary BaP-related cancer risk using carcinogenic potency factor of BaP as 7.3E + 0 (mg/kg/d)(-1) was assessed to be 1.52 x 10(-5). These data suggest that cancer risk due to dietary exposure to BaP is of concern in Koreans and needs to be reduced either by regulatory efforts or by modifying food manufacturing procedures.

  2. Dietary exposure to cadmium and health effects: impact of environmental changes.

    PubMed Central

    Piscator, M

    1985-01-01

    Cadmium exposure, metabolism, and effects are described especially in relation to dietary intakes. Data on dietary intakes in several countries have been complied from studies using the duplicate diet method or fecal analysis. These two methods seem to give more accurate data than estimates based on cadmium concentrations in food classes and food consumption (composite method). The present data on absorption and retention of ingested cadmium indicate that normally less than 5% is ingested, but absorption may increase in women who have iron deficiency. Earlier estimates of the critical concentration in renal cortex being about 200 mg/kg wet weight still seem to be valid. New information is available on present renal levels and their distribution in the general population. The present margin of safety with regard to risk for renal effects is small. To predict future health risks from increases in dietary cadmium due to environmental changes such as acid deposition, it is necessary that the models used are based on correct assumptions. Of interest are the distributions of dietary intake, gastrointestinal absorption, and renal cadmium concentrations. These distributions are normal or lognormal, and since standard deviations are used when estimating risks, it is of paramount importance that the standard deviations are estimated as accurately as possible. At present it is not possible to quantify the effects attributed to acid rain only; account must be also be taken of cadmium added to, e.g., soil by use of sewage sludge and other fertilizers. In addition to risks to human health, cadmium also poses a threat to horses, which generally have renal cadmium concentrations several times higher than adult humans. It is recommended that horses should be monitored in areas when acid deposition is high. Such monitoring might provide valuable information about impact of acid rain. PMID:4076079

  3. Dietary exposure to cadmium and health effects: impact of environmental changes.

    PubMed

    Piscator, M

    1985-11-01

    Cadmium exposure, metabolism, and effects are described especially in relation to dietary intakes. Data on dietary intakes in several countries have been complied from studies using the duplicate diet method or fecal analysis. These two methods seem to give more accurate data than estimates based on cadmium concentrations in food classes and food consumption (composite method). The present data on absorption and retention of ingested cadmium indicate that normally less than 5% is ingested, but absorption may increase in women who have iron deficiency. Earlier estimates of the critical concentration in renal cortex being about 200 mg/kg wet weight still seem to be valid. New information is available on present renal levels and their distribution in the general population. The present margin of safety with regard to risk for renal effects is small. To predict future health risks from increases in dietary cadmium due to environmental changes such as acid deposition, it is necessary that the models used are based on correct assumptions. Of interest are the distributions of dietary intake, gastrointestinal absorption, and renal cadmium concentrations. These distributions are normal or lognormal, and since standard deviations are used when estimating risks, it is of paramount importance that the standard deviations are estimated as accurately as possible. At present it is not possible to quantify the effects attributed to acid rain only; account must be also be taken of cadmium added to, e.g., soil by use of sewage sludge and other fertilizers. In addition to risks to human health, cadmium also poses a threat to horses, which generally have renal cadmium concentrations several times higher than adult humans. It is recommended that horses should be monitored in areas when acid deposition is high. Such monitoring might provide valuable information about impact of acid rain.

  4. Acute and chronic poisoning from residential exposures to elemental mercury--Michigan, 1989-1990

    SciTech Connect

    Not Available

    1991-06-14

    From May 1989 through November 1990, eight episodes of elemental mercury exposure in private residences or schools in the United States were reported to the Agency for Toxic Substances and Disease Registry (ATSDR). The case studies in this report document two of these episodes (both in Michigan) of residential mercury poisoning--one involving acute mercury exposure, and the other, chronic exposure to elemental mercury. These episodes illustrate the differing clinical and toxicologic manifestations of acute and chronic mercury poisoning.

  5. Dietary exposure to an environmental toxin triggers neurofibrillary tangles and amyloid deposits in the brain

    PubMed Central

    Cox, Paul Alan; Davis, David A.; Mash, Deborah C.; Metcalf, James S.; Banack, Sandra Anne

    2016-01-01

    Neurofibrillary tangles (NFT) and β-amyloid plaques are the neurological hallmarks of both Alzheimer's disease and an unusual paralytic illness suffered by Chamorro villagers on the Pacific island of Guam. Many Chamorros with the disease suffer dementia, and in some villages one-quarter of the adults perished from the disease. Like Alzheimer's, the causal factors of Guamanian amyotrophic lateral sclerosis/parkinsonism dementia complex (ALS/PDC) are poorly understood. In replicated experiments, we found that chronic dietary exposure to a cyanobacterial toxin present in the traditional Chamorro diet, β-N-methylamino-l-alanine (BMAA), triggers the formation of both NFT and β-amyloid deposits similar in structure and density to those found in brain tissues of Chamorros who died with ALS/PDC. Vervets (Chlorocebus sabaeus) fed for 140 days with BMAA-dosed fruit developed NFT and sparse β-amyloid deposits in the brain. Co-administration of the dietary amino acid l-serine with l-BMAA significantly reduced the density of NFT. These findings indicate that while chronic exposure to the environmental toxin BMAA can trigger neurodegeneration in vulnerable individuals, increasing the amount of l-serine in the diet can reduce the risk. PMID:26791617

  6. Effects of Dietary Exposure to Zearalenone (ZEN) on Carp (Cyprinus carpio L.)

    PubMed Central

    Pietsch, Constanze; Kersten, Susanne; Valenta, Hana; Dänicke, Sven; Schulz, Carsten; Burkhardt-Holm, Patricia; Junge, Ranka

    2015-01-01

    The mycotoxin zearalenone (ZEN) is frequently contaminating animal feeds including feed used in aquaculture. In the present study, the effects of dietary exposure to ZEN on carp (Cyprinus carpio L.) were investigated. ZEN at three different concentrations (low dose: 332 µg kg−1, medium dose: 621 µg kg−1 and high dose: 797 µg kg−1 final feed, respectively) was administered to juvenile carp for four weeks. Additional groups received the mycotoxin for the same time period but were fed with the uncontaminated diet for two more weeks to examine the reversibility of the ZEN effects. No effects on growth were observed during the feeding trial, but effects on haematological parameters occurred. In addition, an influence on white blood cell counts was noted whereby granulocytes and monocytes were affected in fish treated with the medium and high dose ZEN diet. In muscle samples, marginal ZEN and α-zearalenol (α-ZEL) concentrations were detected. Furthermore, the genotoxic potential of ZEN was confirmed by analysing formation of micronuclei in erythrocytes. In contrast to previous reports on other fish species, estrogenic effects measured as vitellogenin concentrations in serum samples were not increased by dietary exposure to ZEN. This is probably due to the fact that ZEN is rapidly metabolized in carp. PMID:26343724

  7. Dietary aflatoxin exposure and impaired growth in young children from Kisumu District, Kenya: Cross sectional study.

    PubMed

    Okoth, Sheila Adhiambo; Ohingo, Mercy

    2004-01-01

    Cereal grains are the basis of weaning gruel in Kenya yet they run a high risk of mycotoxin contamination. Children could be at a higher risk of dietary mycotoxin exposure than the rest of the population. This paper presents information on the association between nutritional state of children and dietary exposure to aflatoxins in Kisumu District. Weaning flour samples were collected randomly from 242 households in Kisumu District, Kenya. A questionnaire was used to collect information, from mothers whose flour were sampled, on the types of weaning foods, handling and storage. The nutritional status of the children in question was assessed and their weight and height measured. The flour samples were analyzed for aflatoxins by thin layer chromatography. Cultural studies of the flour were also done. Thirty one percent of the children were malnourished. The number of children who were wasting and were being fed on flour contaminated with mycotoxins was highly significant (P = 0.002). Seventy samples (29 %) were positive for aflatoxins (concentration range 2-82 mg / kg), some exceeding the advisory limit.

  8. Dietary Exposure and Natural Occurrence of Total Aflatoxins in Basmati Rice of Pakistan.

    PubMed

    Sultana, Nighat; Tahira, Iffat; Kausar, Mumtaz; Hassan, Syed Mujahid; Hanif, Nafeesa Qudsia

    2017-02-01

    This study presents the assessment of total aflatoxins (TAFs) in basmati rice (brown, 1,081; white, 1,170) collected from different areas of Punjab, Pakistan, during 2010 to 2015. Due to the carcinogenicity of TAFs, daily dietary exposure is also evaluated based on rice consumption survey data. Methodology was standardized by matrix spike recoveries at four fortification levels (0.1, 0.5, 2.5, and 12.5 ng/g) for TAFs (aflatoxins B1 [AFB1], B2 [AFB2], G1 [AFG1], and G2 [AFG2]). The present study reveals that 1,750 samples (77.74%) were tainted with AFB1, whereas TAFs were detected in 370 samples (16.43%). Of positive samples, 854 brown rice samples (79%) were positive for AFB1, and 154 samples (14.24%) were contaminated with TAFs. For white rice, 896 samples (76.58%) were contaminated with AFB1, whereas 205 samples (18.46%) were found positive for TAFs. Study findings were used to construct a frequency distribution, and AFB1 levels were also compared against permissible levels of TAFs (10 ng/g) as legislated by the European Commission. Results further revealed that daily dietary exposure of TAFs ranged from 0.51 to 10.22 ng/kg of body weight per day, which exceeds the permissible limit of 1 ng/kg of body weight per day as defined by the Joint FAO/WHO Expert Committee on Food Additives.

  9. Hormone Use in Food Animal Production: Assessing Potential Dietary Exposures and Breast Cancer Risk.

    PubMed

    Nachman, Keeve E; Smith, Tyler J S

    2015-03-01

    In recent years, increasing attention has been paid to the role of hormones in breast cancer etiology, following reports that heightened levels of endogenous hormones and exposure to exogenous hormones and other endocrine-disrupting chemicals through food and the environment are associated with increased breast cancer risk. Seven hormone drugs (testosterone propionate, trenbolone acetate, estradiol, zeranol, progesterone, melengestrol acetate, and bovine somatotropin) are approved by the U.S. Food and Drug Administration for use in food animals. There is concern that these drugs or their biologically active metabolites may accumulate in edible tissues, potentially increasing the risk of exposure for consumers. To date, the potential for human exposure to residues of these compounds in animal products, as well as the risks that may result from this exposure, is poorly understood. In this paper, we discuss the existing scientific evidence examining the toxicological significance of exposure to hormones used in food animal production in relation to breast cancer risk. Through a discussion of U.S. federal regulatory programs and the primary literature, we interpret the state of surveillance for residues of hormone drugs in animal products and discuss trends in meat consumption in relation to the potential for hormone exposure. Given the lack of chronic bioassays of oral toxicity of the seven hormone compounds in the public literature and the limitations of existing residue surveillance programs, it is not currently possible to provide a quantitative characterization of risks that result from the use of hormonal drugs in food animal production, complicating our understanding of the role of dietary hormone exposure in the population burden of breast cancer.

  10. QSAR Modeling of Rat Acute Toxicity by Oral Exposure

    PubMed Central

    Zhu, Hao; Martin, Todd M.; Ye, Lin; Sedykh, Alexander; Young, Douglas M.; Tropsha, Alexander

    2009-01-01

    Few Quantitative Structure-Activity Relationship (QSAR) studies have successfully modeled large, diverse rodent toxicity endpoints. In this study, a comprehensive dataset of 7,385 compounds with their most conservative lethal dose (LD50) values has been compiled. A combinatorial QSAR approach has been employed to develop robust and predictive models of acute toxicity in rats caused by oral exposure to chemicals. To enable fair comparison between the predictive power of models generated in this study versus a commercial toxicity predictor, TOPKAT (Toxicity Prediction by Komputer Assisted Technology), a modeling subset of the entire dataset was selected that included all 3,472 compounds used in the TOPKAT’s training set. The remaining 3,913 compounds, which were not present in the TOPKAT training set, were used as the external validation set. QSAR models of five different types were developed for the modeling set. The prediction accuracy for the external validation set was estimated by determination coefficient R2 of linear regression between actual and predicted LD50 values. The use of the applicability domain threshold implemented in most models generally improved the external prediction accuracy but expectedly led to the decrease in chemical space coverage; depending on the applicability domain threshold, R2 ranged from 0.24 to 0.70. Ultimately, several consensus models were developed by averaging the predicted LD50 for every compound using all 5 models. The consensus models afforded higher prediction accuracy for the external validation dataset with the higher coverage as compared to individual constituent models. The validated consensus LD50 models developed in this study can be used as reliable computational predictors of in vivo acute toxicity. PMID:19845371

  11. Dietary exposure to non-dioxin-like PCBs of different population groups in Austria.

    PubMed

    Mihats, Daniela; Moche, Wolfgang; Prean, Michael; Rauscher-Gabernig, Elke

    2015-05-01

    The dietary exposure to the sum of the six indicator PCBs (Σ6 PCBs; PCB 28, 52, 101, 138, 153, and 180) across different Austrian population groups was assessed in this study by combining data on occurrence from food of the Austrian market (n=157) analysed during 2006-2011 with national food consumption data. The most contaminated food group was meat, poultry, game and offal with average levels of ndl-PCBs of 5.20 ng g(-1) fat. In fish and fish products and eggs, mean concentrations of 3.89 ng g(-1) fresh weight (fw) and 4.00 ng g(-1) fat, respectively, were found. In milk and dairy products average concentrations ranged from 3.07 to 4.44 ng g(-1) fat. The mean dietary intake of Σ6 PCBs was estimated to be 3.37 ng kg(-1) bw d(-1) for children (6-15 years old), 3.19 ng kg(-1) bw d(-1) for women (19-65 years) and 2.64 ng kg(-1) bw d(-1) for men (19-65 years). In all three population groups, milk and dairy products was the major contributing food group to the total dietary intake (50-55%) followed by fish and fish products (23-27%). The exposure of all Austrian population groups is well below the tolerable daily intake (TDI) of 10 ng kg(-1) bw d(-1) proposed by WHO, accounting for 34% in children, 32% in women and 26% in men.

  12. Dietary BMAA Exposure in an Amyotrophic Lateral Sclerosis Cluster from Southern France

    PubMed Central

    Masseret, Estelle; Banack, Sandra; Boumédiène, Farid; Abadie, Eric; Brient, Luc; Pernet, Fabrice; Juntas-Morales, Raoul; Pageot, Nicolas; Metcalf, James; Cox, Paul; Camu, William

    2013-01-01

    Background Dietary exposure to the cyanotoxin BMAA is suspected to be the cause of amyotrophic lateral sclerosis in the Western Pacific Islands. In Europe and North America, this toxin has been identified in the marine environment of amyotrophic lateral sclerosis clusters but, to date, only few dietary exposures have been described. Objectives We aimed at identifying cluster(s) of amyotrophic lateral sclerosis in the Hérault district, a coastal district from Southern France, and to search, in the identified area(s), for the existence of a potential dietary source of BMAA. Methods A spatio-temporal cluster analysis was performed in the district, considering all incident amyotrophic lateral sclerosis cases identified from 1994 to 2009 by our expert center. We investigated the cluster area with serial collections of oysters and mussels that were subsequently analyzed blind for BMAA concentrations. Results We found one significant amyotrophic lateral sclerosis cluster (p = 0.0024), surrounding the Thau lagoon, the most important area of shellfish production and consumption along the French Mediterranean coast. BMAA was identified in mussels (1.8 µg/g to 6.0 µg/g) and oysters (0.6 µg/g to 1.6 µg/g). The highest concentrations of BMAA were measured during summer when the highest picocyanobacteria abundances were recorded. Conclusions While it is not possible to ascertain a direct link between shellfish consumption and the existence of this ALS cluster, these results add new data to the potential association of BMAA with sporadic amyotrophic lateral sclerosis, one of the most severe neurodegenerative disorder. PMID:24349504

  13. Dietary BMAA exposure in an amyotrophic lateral sclerosis cluster from southern France.

    PubMed

    Masseret, Estelle; Banack, Sandra; Boumédiène, Farid; Abadie, Eric; Brient, Luc; Pernet, Fabrice; Juntas-Morales, Raoul; Pageot, Nicolas; Metcalf, James; Cox, Paul; Camu, William

    2013-01-01

    Dietary exposure to the cyanotoxin BMAA is suspected to be the cause of amyotrophic lateral sclerosis in the Western Pacific Islands. In Europe and North America, this toxin has been identified in the marine environment of amyotrophic lateral sclerosis clusters but, to date, only few dietary exposures have been described. We aimed at identifying cluster(s) of amyotrophic lateral sclerosis in the Hérault district, a coastal district from Southern France, and to search, in the identified area(s), for the existence of a potential dietary source of BMAA. A spatio-temporal cluster analysis was performed in the district, considering all incident amyotrophic lateral sclerosis cases identified from 1994 to 2009 by our expert center. We investigated the cluster area with serial collections of oysters and mussels that were subsequently analyzed blind for BMAA concentrations. We found one significant amyotrophic lateral sclerosis cluster (p = 0.0024), surrounding the Thau lagoon, the most important area of shellfish production and consumption along the French Mediterranean coast. BMAA was identified in mussels (1.8 µg/g to 6.0 µg/g) and oysters (0.6 µg/g to 1.6 µg/g). The highest concentrations of BMAA were measured during summer when the highest picocyanobacteria abundances were recorded. While it is not possible to ascertain a direct link between shellfish consumption and the existence of this ALS cluster, these results add new data to the potential association of BMAA with sporadic amyotrophic lateral sclerosis, one of the most severe neurodegenerative disorder.

  14. Acute exposure to acid fog. Effects on mucociliary clearance

    SciTech Connect

    Laube, B.L.; Bowes, S.M. III; Links, J.M.; Thomas, K.K.; Frank, R. )

    1993-05-01

    Submicrometric sulfuric acid (H2SO4) aerosol can affect mucociliary clearance without eliciting irritative symptoms or changes in pulmonary function. The effect of larger fog droplets containing H2SO4 on mucociliary clearance is unknown. We quantified mucociliary clearance from the trachea (n = 4) and small airways (n = 7) of young healthy male adults after an acute exposure to H2SO4 fog (MMAD = 10.3 microns; pH = 2.0; liquid water content = 481 +/- 65 mg/m3; osmolarity = 30 mOsm). Acid fog (AF) or saline fog (SF) (10.9 microns; 492 +/- 116 mg/m3; 30 mOsm) was administered for 40 min of unencumbered breathing (no mouth-piece) at rest and for 20 min of exercise sufficient to produce oronasal breathing. Fog exposures were followed by a methacholine (MCh) challenge (a measure of airway reactivity) or inhalation of technetium-99M radioaerosol (MMAD = 3.4 microns) on 2 study days each. Changes in symptoms and forced ventilatory function were also assessed. Clearance was quantified from computer-assisted analyses of gamma camera images of the lower respiratory tract in terms of %removal/min of the radiolabel from the trachea 25 min after inhalation and from the outer zone of the right lung after 1.9 to 3 h. Symptoms, forced ventilatory function, and MCh response were unaffected by either fog. Tracheal clearance was more rapid in four of four subjects after AF (0.83 +/- 1.58% removal/min) compared with that after SF (-0.54 +/- 0.85% removal/min). Outer zone clearance was more rapid in six of seven subjects after AF (0.22 +/- 0.15% removal/min) compared with that after SF (0.01 +/- 0.09% removal/min).

  15. Dietary exposure and neurotoxicity of the environmental free and bound toxin β-N-methylamino-l-alanine.

    PubMed

    Regueiro, Jorge; Negreira, Noelia; Carreira-Casais, Anxo; Pérez-Lamela, Conchi; Simal-Gándara, Jesús

    2017-10-01

    The growing evidence supporting a link between exposure to the naturally occurring toxin β-N-methylamino-l-alanine (BMAA) and progressive neurodegenerative diseases, has recently arisen the interest of the scientific community. Latest investigations suggest that dietary exposure to this algal toxin may have been largely underestimated. This paper reviews the state of the art regarding BMAA, with special attention paid to its neurotoxicity, its concentration levels in food, and human exposure. As for other environmental toxins, dietary intake is most likely the main route of exposure to BMAA for the general population. However, data concerning BMAA levels in foodstuffs are still scarce. It is concluded that further investigations on dietary intake and potential human health effects are clearly necessary to assess the risks to public health associated with BMAA exposure. Some critical remarks and recommendations on future research in this area are provided, which may help to identify approaches to reduce dietary BMAA exposure. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Occurrence and human non-dietary exposure of polycyclic aromatic hydrocarbons in soils from Shenzhen, China.

    PubMed

    Cao, Shan-Ping; Ni, Hong-Gang; Qin, Pei-Heng; Zeng, Hui

    2010-07-08

    Twenty eight polycyclic aromatic hydrocarbons (PAHs) were determined for a total of 203 top soil samples collected from eight different land categories in Shenzhen, China during the winter of 2007. The concentrations, compositional profile, and the potential sources of PAHs in soil were discussed. Overall, PAH pollution in the soil of Shenzhen is still in the low-end of the world after 30 years rapid urbanization. Based on that, human exposure to soil PAHs via inhalation and soil particle intake were estimated as well. The concentrations of Sigma(28)PAHs in Shenzhen soil ranged from 2.68 to 17,767 ng g(-1) (average: 546 ng g(-1)). The highest levels of PAHs were found in the traffic land (average: 2104 ng g(-1)) and the lowest concentrations were detected in forest land (average: 144 ng g(-1)) in eight land categories. PAH isomeric ratios indicated that PAHs in Shenzhen soil were mainly derived from combustion. In the current pollution levels in Shenzhen, children aged 0 to 8 were the most sensitive sub-group of exposure to PAHs (59.2 ng (kg d)(-1)), and the exposure to PAHs for males (36.2 ng (kg d)(-1)) was more serious than for females (32.7 ng (kg d)(-1)). Inhalation was the major way of non-dietary exposure (over 96%).

  17. Concentrations of environmental organic contaminants in meat and meat products and human dietary exposure: A review.

    PubMed

    Domingo, José L

    2017-09-01

    Meat and meat products is one of the most relevant food groups in an important number of human diets. Recently, the IARC, based on results of a number of epidemiological studies, classified the consumptions of red meat and processed meat as "probably carcinogenic to humans" and as "carcinogenic to humans", respectively. It was suggested that the substances responsible of the potential carcinogenicity would be mainly generated during meat processing, such as curing and smoking, or when meat is heated at high temperatures. However, the exposure to environmental pollutants through meat consumption was not discussed. The purpose of the present paper was to review recent studies reporting the concentrations of PCDD/Fs, DL-PCBs and PAHs in meat and meat products, as well as the human exposure to these pollutants through the diet. It is concluded that the health risks derived from exposure to carcinogenic environmental contaminants must be considered in the context of each specific diet, which besides meat and meat products, includes other foodstuffs containing also chemical pollutants, some of them with carcinogenic potential. Anyhow, meat and meat products are not the main food group responsible of the dietary exposure to carcinogenic (or probably carcinogenic) environmental organic pollutants. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Quantification of estragole in fennel herbal teas: implications on the assessment of dietary exposure to estragole.

    PubMed

    Raffo, Antonio; Nicoli, Stefano; Leclercq, Catherine

    2011-02-01

    Quantification of estragole content in commercial fennel herbal teas was carried out in order to allow for a more accurate estimate of the dietary exposure to estragole. A simple and rapid analytical method, based on Stir Bar Sorptive Extraction and GC-MS, was developed for this purpose. Fennel teas obtained from different types of commercial products were analysed. Concentration levels ranged from 241 to 2058 μg L(-1) in teas from teabags, from 9 to 912 μg L(-1) in diluted instant teas, from 251 to 1718 μg L(-1) in teas from not packaged seeds. Based on these data and considering the daily consumption of three portions of herbal tea, a maximum exposure to estragole for adults of 10 μg/kg bw/day was calculated. The relatively high level observed in diluted instant teas of some brands deserves attention since these products are designed for infant consumption. Estimated exposure in infants was up to 51 μg/kg bw/day for teas from teabags, and up to 23 μg/kg bw/day for instant teas. A generalization of the use of suitable technologies in production processes of instant teas could substantially reduce the exposure to estragole in the vulnerable population groups (infants, young children, pregnant and breastfeeding women) who consume these products.

  19. Acute effects of exposure to 56Fe and 16O particles on learning and memory

    USDA-ARS?s Scientific Manuscript database

    Although it has been shown that exposure to HZE particles disrupts cognitive performance when tested 2-4 weeks after irradiation, it has not been determined whether exposure to HZE particles can exert acute effects on cognitive performance; i.e., effects within 4-48 hrs after exposure. The present ...

  20. Dietary and waterborne exposure of rainbow trout (Oncorhynchus mykiss) to copper, cadmium, lead and zinc using a live diet

    SciTech Connect

    Mount, D.R.; Barth, A.K.; Garrison, T.D.; Barten, K.A.; Hockett, J.R. )

    1994-12-01

    In two 60-d exposures, rainbow trout fry were fed brine shrimp (Artemia sp.) enriched with Cu, Cd, Pb, and Zn both individually and as a mixture combined with As. Dietary concentrations fed to trout were selected based on metal concentrations measured in invertebrates collected from the Clark Fork River (CFR), Montana. In addition to dietary exposure, treatments also included simultaneous exposure to a mixture of waterborne metals at sublethal concentrations. Fish in all treatments showed increased tissue metal concentrations from water and/or dietary exposure. Despite these accumulations, trout showed no effects on survival or growth from dietary concentrations as high as 55 [mu]g Cd/g dry weight, 170 [mu]g Pb/g dry weight, or 1,500 [mu]g Zn/g dry weight. Dietary Cu concentrations up to 350 [mu]g Cu/g dry weight did not reduce survival or growth. Fish fed Cu concentrations higher than those typical of CFR invertebrates showed about 30% mortality with no effect on growth; waterborne Cu released from Artemia may have contributed to this mortality. Trout exposed to diets with a mixture of Cu, Cd, Pb, Zn, and As close to that measured in CFR invertebrates showed lower weight than did control fish after 35 d, but this difference was no longer present after 60 d.

  1. Exhaled nitric oxide concentration upon acute exposure to moderate altitude.

    PubMed

    Caspersen, C; Stang, J; Thorsen, E; Stensrud, T

    2013-03-01

    The purpose of this study was to assess immediate changes in the partial pressure of nitric oxide (NO) in exhaled gas (PE NO ) in healthy trained subjects who were acutely exposed to moderate altitude. One group of nine and another group of 20 healthy subjects were exposed to an ambient pressure of 728 hPa (546 mmHg) corresponding to an altitude of 2800 m for 5 and 90 min, respectively, in an altitude chamber. PE NO was measured offline by sampling exhaled gas in tight metal foil bags at 5, 30, 60, and 90 min. A correction for increased expiratory flow rate due to gas density effects at altitude was performed (PE NO corr). PE NO was significantly decreased by 13-16%, while the fraction of NO in exhaled gas (FE NO) was increased by 16-19% compared to sea level. There was no significant change in PE NO corr after exposure to altitude for 5, 30, 60, and 90 min. We conclude that there was no change in PENO upon arrival at altitude after correcting for gas density effects on expiratory flow rate. Corrections for altitude effects must be done before comparing measurements performed at different altitudes when using measurements of FENO to monitor athletes who have asthma during training at altitude.

  2. Aluminum exposure for 60days at an equivalent human dietary level promotes peripheral dysfunction in rats.

    PubMed

    Martinez, Caroline Silveira; Vera, Gema; Ocio, José Antonio Uranga; Peçanha, Franck Maciel; Vassallo, Dalton Valentim; Miguel, Marta; Wiggers, Giulia Alessandra

    2017-08-25

    Aluminum (Al) is a neurotoxic associated with a number of chronic human diseases. We investigated the effects of Al exposure at doses similar to human dietary levels and at a high level exposure to Al on the peripheral nervous system. Wistar male rats were divided into two major groups and received orally: 1) First group - Low level - rats were subdivided and treated for 60days: a) Control - received ultrapure water; b) AlCl3 - received Al at 8.3mg/kg body weight (bw) for 60days; and 2) Second group - High level - rats were subdivided and treated for 42days: C) Control - received ultrapure water through oral gavage; d) AlCl3 - received Al at 100mg/kg bw for 42days. Von Frey hair test, plantar test, the presence of catalepsy and the spontaneous motor activity were investigated. Reactive oxygen species, lipid peroxidation and total antioxidant capacity, immunohistochemistry to investigate the nerve inflammation and, the specific presence of Al in the sciatic nerve fibers were investigated. Al exposure at a representative human dietary level promotes the development of mechanical allodynia, catalepsy, increased inflammation in the sciatic nerve, systemic oxidative stress and, is able to be retained in the sciatic nerve. The effects of low-dose Al were similar to those found in rats exposed to Al at a dose much higher (100mg/kg). Our findings suggest that Al may be considered toxic for the peripheral nervous system, thus inducing peripheral dysfunction. Copyright © 2017 Elsevier Inc. All rights reserved.

  3. Nutritional status and dietary intake of children with acute leukaemia during induction or consolidation chemotherapy.

    PubMed

    Tan, S Y; Poh, B K; Nadrah, M H; Jannah, N A; Rahman, J; Ismail, M N

    2013-07-01

    The assessment of nutritional status among paediatric patients is important for the planning and execution of nutritional strategies that strive to optimise the quality of life and growth among sick children. The present study aimed to evaluate the nutritional status and dietary intake among children with acute leukaemia. This cross-sectional study included 53 paediatric patients aged 3-12 years old, who were diagnosed with either acute lymphoblastic leukaemia or acute myelogenous leukaemia and were undergoing chemotherapy treatments (induction or consolidation phase). Patients were matched for sex, age (±6 months) and ethnicity with healthy children as controls. Weight, height, body mass index, waist circumference, mid-upper arm circumference, triceps skinfold thickness, mid-upper arm muscle area and fat area were determined. Dietary intake was assessed using 3-day food records. Anthropometric variables were generally higher among patients compared to controls, although the differences were not statistically significant (P > 0.05). The prevalence of overnutrition among patients according to body mass index-for-age, waist circumference-for-age, mid-upper arm circumference-for-age and triceps skinfold-for-age were 24.5%, 29.1%, 17.0% and 30.2%, respectively. Mean energy [5732 ± 1958 kJ (1370 ± 468 kcal) versus 6945 ± 1970 kJ (1660 ± 471 kcal), P < 0.01], protein (50.0 ± 19.7 g versus 62.3 ± 22.3 g, P < 0.01) and fat (43.6 ± 18.9 g versus 58.3 ± 16.7, P < 0.001) intakes of patients were significantly lower than controls. The prevalence of being overweight and obesity in children with acute leukaemia was higher despite lower energy intake compared to controls. Studies assessing physical activity, the complex interaction and the effects of treatment drugs are warranted to better manage malnutrition among paediatric patients. © 2013 The Authors Journal of Human Nutrition and Dietetics © 2013 The British Dietetic Association

  4. Riboflavin status in acutely ill patients and response to dietary supplements.

    PubMed

    Gariballa, Salah; Forster, Sarah; Powers, Hilary

    2009-01-01

    Although a number of studies have reported riboflavin deficiency in free-living older people, no data are available on riboflavin intake and status in older people during acute illness. To determine the riboflavin response to dietary supplements during acute illness, 297 hospitalized, acutely ill older patients are randomly assigned to receive a daily oral nutritional supplement containing 1.3 mg of riboflavin or a placebo for 6 weeks. Outcome measures are riboflavin intake and riboflavin biochemical status at baseline, 6 weeks, and 6 months using the erythrocyte glutathione reductase activation coefficient (EGRAC), a measure of riboflavin tissue saturation. EGRAC values are inversely proportional to riboflavin status. Fifty-six percent of patients (167/297) have suboptimal riboflavin status (EGRAC > 1.30). No significant correlation is found between EGRAC and either total energy or riboflavin intakes. Significant correlations are found between total energy intake and riboflavin intakes both in hospital and at home (r = 0.67, P < .0001 and r = 0.57, P < .0001, respectively). Smokers and patients with chronic obstructive pulmonary disease (COPD) have lower riboflavin status (high EGRAC values) compared with nonsmokers and those without COPD. Riboflavin status improves significantly in the supplement group at 6 weeks compared with the placebo group, but status declines between 6 weeks and 6 months, after patients stop taking the supplements. A high proportion of acutely ill patients have suboptimal riboflavin status. Supplementation with a physiological amount of riboflavin in a mixed-nutrient supplement significantly improves riboflavin status, but the effect is transient and status deteriorates again after patients stop taking the supplements.

  5. Dietary sugar beet fiber ameliorates diarrhea as an acute gamma-radiation injury in rats.

    PubMed

    Ishizuka, S; Ito, S; Kasai, T; Hara, H

    2000-09-01

    Gamma radiation induces diarrhea as an acute injury. We have studied whether ingestion of sugar beet fiber influences radiation-induced diarrhea. Abdominal irradiation with gamma rays induced diarrhea in male Wistar/ST rats from 2 to 7 days after a single sublethal dose. The body weight of the irradiated rats was decreased temporarily at 4 days after irradiation regardless of the ingestion of sugar beet fiber. At day 8, it returned to almost the same level as that of unirradiated rats. A change in daily food intake resulted in a pattern similar to that for body weight. Dietary sugar beet fiber had little significant effect on the changes in body weight and daily food intake, and its ingestion significantly decreased gamma-ray-induced diarrhea. Changes in biochemical and histological parameters in intestinal mucosa (small intestine, cecum and colon) were not greatly influenced by the ingestion of sugar beet fiber through the periods of diarrhea. It was concluded that dietary sugar beet fiber ameliorated the diarrhea induced by abdominal irradiation. We suggest that the inhibitory effect of the ingestion of sugar beet fiber is due to its effects on the luminal environment, such as support for bacterial function in the luminal contents in the colon of animals that ingest sugar beet fiber.

  6. Dietary flaxseed intake exacerbates acute colonic mucosal injury and inflammation induced by dextran sodium sulfate.

    PubMed

    Zarepoor, Leila; Lu, Jenifer T; Zhang, Claire; Wu, Wenqing; Lepp, Dion; Robinson, Lindsay; Wanasundara, Janitha; Cui, Steve; Villeneuve, Sébastien; Fofana, Bourlaye; Tsao, Rong; Wood, Geoffrey A; Power, Krista A

    2014-06-15

    Flaxseed (FS), a dietary oilseed, contains a variety of anti-inflammatory bioactives, including fermentable fiber, phenolic compounds (lignans), and the n-3 polyunsaturated fatty acid (PUFA) α-linolenic acid. The objective of this study was to determine the effects of FS and its n-3 PUFA-rich kernel or lignan- and soluble fiber-rich hull on colitis severity in a mouse model of acute colonic inflammation. C57BL/6 male mice were fed a basal diet (negative control) or a basal diet supplemented with 10% FS, 6% kernel, or 4% hull for 3 wk prior to and during colitis induction via 5 days of 2% (wt/vol) dextran sodium sulfate (DSS) in their drinking water (n = 12/group). An increase in anti-inflammatory metabolites (hepatic n-3 PUFAs, serum mammalian lignans, and cecal short-chain fatty acids) was associated with consumption of all FS-based diets, but not with anti-inflammatory effects in DSS-exposed mice. Dietary FS exacerbated DSS-induced acute colitis, as indicated by a heightened disease activity index and an increase in colonic injury and inflammatory biomarkers [histological damage, apoptosis, myeloperoxidase, inflammatory cytokines (IL-6 and IL-1β), and NF-κB signaling-related genes (Nfkb1, Ccl5, Bcl2a1a, Egfr, Relb, Birc3, and Atf1)]. Additionally, the adverse effect of the FS diet was extended systemically, as serum cytokines (IL-6, IFNγ, and IL-1β) and hepatic cholesterol levels were increased. The adverse effects of FS were not associated with alterations in fecal microbial load or systemic bacterial translocation (endotoxemia). Collectively, this study demonstrates that although consumption of a 10% FS diet enhanced the levels of n-3 PUFAs, short-chain polyunsaturated fatty acids, and lignans in mice, it exacerbated DSS-induced colonic injury and inflammation.

  7. Herbal and dietary supplements related to diarrhea and acute kidney injury: a case report.

    PubMed

    Wanitsriphinyo, Suphamat; Tangkiatkumjai, Mayuree

    2017-03-01

    Background There is very little evidence relating to the association of herbal medicine with diarrhea and the development of acute kidney injury (AKI). This study reports a case of diarrhea-induced AKI, possibly related to an individual ingesting copious amounts of homemade mixed fruit and herb puree. Case presentation A 45-year-old Thai man with diabetes had diarrhea for 2 days, as a result of taking high amounts of a puree made up of eight mixed fruits and herbs over a 3-day period. He developed dehydration and stage 2 AKI, with a doubling of his serum creatinine. He had been receiving enalapril, as a prescribed medication, over one year. After he stopped taking both the puree and enalapril, and received fluid replacement therapy, within a week his serum creatinine had gradually decreased. The combination of puree, enalapril and AKI may also have induced hyperkalemia in this patient. Furthermore, the patient developed hyperphosphatemia due to his worsening kidney function, exacerbated by regularly taking some dietary supplements containing high levels of phosphate. His serum levels of potassium and phosphate returned to normal within a week, once the patient stopped both the puree and all dietary supplements, and had begun receiving treatment for hyperkalemia. Results The mixed fruit and herb puree taken by this man may have led to his diarrhea due to its effect; particularly if the patient was taking a high concentration of such a drink. Both the puree and enalapril are likely to attenuate the progression of kidney function. The causal relationship between the puree and AKI was probable (5 scores) assessed by the modified Naranjo algorithm. This is the first case report, as far as the authors are aware, relating the drinking of a mixed fruit and herbal puree to diarrhea and AKI in a patient with diabetes. Conclusions This case can alert health care providers to the possibility that herbal medicine could induce diarrhea and develop acute kidney injury.

  8. Application of a source-to-outcome model for the assessment of health impacts from dietary exposures to insecticide residues.

    PubMed

    Price, Paul S; Schnelle, Karl D; Cleveland, Cheryl B; Bartels, Michael J; Hinderliter, Paul M; Timchalk, Charles; Poet, Torka S

    2011-10-01

    The paper presents a case study of the application of a "source-to-outcome" model for the evaluation of the health outcomes from dietary exposures to an insecticide, chlorpyrifos, in populations of adults (age 30) and children (age 3). The model is based on publically-available software programs that characterize the longitudinal dietary exposure and anthropometry of exposed individuals. These predictions are applied to a validated PBPK/PD model to estimate interindividual and longitudinal variation in brain and RBC AChE inhibition (key events) and chlorpyrifos concentrations in blood and TCPy in urine (biomarkers of exposure). The predicted levels of chlorpyrifos and TCPy are compared to published measurements of the biomarkers. Predictions of RBC AChE are compared to levels of inhibition associated with reported exposure-related effects in humans to determine the potential for the occurrence of adverse cholinergic effects. The predicted distributions of chlorpyrifos in blood and TCPy in urine were found to be reasonably consistent with published values, supporting the predictive value of the exposure and PBPK portions of the source-to-outcome model. Key sources of uncertainty in predictions of dietary exposures were investigated and found to have a modest impact on the model predictions. Future versions of this source-to-outcome model can be developed that consider advances in our understanding of metabolism, to extend the approach to other age groups (infants), and address intakes from other routes of exposure.

  9. Effects of dietary polychlorinated biphenyl exposure on energetics of white-footed mouse, Peromyscus leucopus

    USGS Publications Warehouse

    Voltura, M.B.; French, J.B.

    2000-01-01

    Energy budgets have provided physiological ecologists with a vital link between environmental variables and individual performance and should also prove useful to ecotoxicologists in understanding the effects of sublethal exposure in the field. Exposure to toxic compounds is likely to be metabolically expensive and may result in a trade-off between energy spent to detoxify and excrete contaminants and energy allocated to growth or reproduction. To quantify the energetic cost of polychlorinated biphenyl (PCB) exposure, we fed captive white-footed mice (Peromyscus leucopus) diets containing PCBs (2:1 Aroclor? 1242:1254) at levels of 0, 0.1, 10, and 25 ppm (mg PCBs/kg food). After six weeks on the diets, there were no differences in food intake (g/d), diet digestibility (%), or body mass related to the level of dietary PCBs. This indicated that short-term exposure to PCBs did not cause a detectable increase in energy need as measured by voluntary food intake. We continued to feed mice the PCB-containing diets for one year, at which time we repeated the food intake trial, and also measured oxygen consumption at 20 and 30 C. After one year, all mice had gained mass, but mice on the 25-ppm diet tended to be heavier than mice in the other groups. Compared to the control group, mice on the 25-ppm diet had higher food intake (4.1 vs 3.7 g/d; p = 0.06) and higher oxygen consumption at 30 C (40.1 vs 36.6 ml O2/h; p = 0.01). These results suggest that there is an energetic cost to long-term contaminant exposure that, when combined with other environmental stresses, may influence patterns of energy acquisition and allocation.

  10. A framework to determine the effectiveness of dietary exposure mitigation to chemical contaminants.

    PubMed

    van der Fels-Klerx, H J Ine; Edwards, Simon G; Kennedy, Marc C; O'Hagan, Sue; O'Mahony, Cian; Scholz, Gabriele; Steinberg, Pablo; Chiodini, Alessandro

    2014-12-01

    In order to ensure the food safety, risk managers may implement measures to reduce human exposure to contaminants via food consumption. The evaluation of the effect of a measure is often an overlooked step in risk analysis process. The aim of this study was to develop a systematic approach for determining the effectiveness of mitigation measures to reduce dietary exposure to chemical contaminants. Based on expert opinion, a general framework for evaluation of the effectiveness of measures to reduce human exposure to food contaminants was developed. The general outline was refined by application to three different cases: 1) methyl mercury in fish and fish products, 2) deoxynivalenol in cereal grains, and 3) furan in heated products. It was found that many uncertainties and natural variations exist, which make it difficult to assess the impact of the mitigation measure. Whenever possible, quantitative methods should be used to describe the current variation and uncertainty. Additional data should be collected to cover natural variability and reduce uncertainty. For the time being, it is always better for the risk manager to have access to all available information, including an assessment of uncertainty; however, the proposed methodology provides a conceptual framework for addressing these systematically.

  11. Dietary exposure of acrylamide from the fifth Chinese Total Diet Study.

    PubMed

    Gao, Jie; Zhao, Yunfeng; Zhu, Feng; Ma, Yongjian; Li, Xiaowei; Miao, Hong; Wu, Yongning

    2016-01-01

    The levels of acrylamide in 240 food composite samples from the 5th Chinese Total Diet Study (TDS) were measured using an LC-MS/MS method and the exposure estimates for the general population were evaluated. The samples were collected from 20 provinces in China, covering about two thirds of the Chinese population. Acrylamide was detected in 40.0% of composite samples with the concentrations ranged from 0.8 to 211.8 μg/kg. The average dietary intakes from the 5th Chinese TDS were 0.319 μg kg(-1) bw day(-1) and an increase with about 70% was observed from the 3rd Chinese TDS in 2000 to the 5th Chinese TDS between 2009 and 2012. The main food group contributors to acrylamide exposure were vegetables (35.2%), cereals (34.3%) and potatoes (15.7%). Based on the benchmark dose lower confidence limit at 10% risk (BMDL10) of 0.31 mg kg(-1) bw day(-1) for the induction of mammary tumors in rats and 0.18 mg kg(-1) bw day(-1) for Harderian gland tumors in mice, the margins of exposure (MOEs) were 973 and 565 for Chinese general population, respectively. These MOEs indicate a human health concern. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Effects of dietary exposure of polycyclic musk HHCB on the metamorphosis of Xenopus laevis.

    PubMed

    Pablos, María Victoria; Jiménez, María Ángeles; San Segundo, Laura; Martini, Federica; Beltrán, Eulalia; Fernández, Carlos

    2016-06-01

    The compound 1,3,4,6,7,8-hexahydro-4,6,6,7,8,8-hexamethylcyclopenta-[γ]-2-benzopyrane (HHCB; galaxolide, Chemical Abstracts Service number 1222-05-5) is a synthetic musk used extensively as a fragrance in many consumer products and classified as an emerging pollutant. The ecotoxicological information available for HHCB addresses exposure via water, but this compound is frequently adsorbed into particulate matter. The goal of the present study was to assess the effects of dietary exposure to several environmentally relevant HHCB concentrations adsorbed in food during Xenopus laevis metamorphosis. The authors sought to determine if such exposure to this synthetic musk resulted in histological changes in the thyroid gland in conjunction with changes in development (staging, timing to metamorphosis), body weight, and length. Developmental acceleration on day 14, together with hypertrophy of the thyroid follicular epithelium in tadpoles, suggested a possible agonistic effect of HHCB, which would have been compensated after metamorphosis by regulatory mechanisms to maintain homeostasis. Further research into the potential thyroid-related mechanisms of action of HHCB should be conducted. Environ Toxicol Chem 2016;35:1428-1435. © 2015 SETAC. © 2015 SETAC.

  13. Probabilistic dietary exposure to phycotoxins in a recreational shellfish harvester subpopulation (France).

    PubMed

    Picot, Cyndie; Limon, Gwendolina; Durand, Gaël; Parent-Massin, Dominique; Roudot, Alain-Claude

    2013-07-01

    Phycotoxins, secondary phytoplankton metabolites, are considered as an important food safety issue because their accumulation by shellfish may render them unfit for human consumption. However, the likely intakes of phycotoxins via shellfish consumption are almost unknown because both contamination and consumption data are very scarce. Thus, two 1-year surveys were conducted (through the same population: recreational shellfish harvesters and from the same geographical area) to assess: shellfish consumption and contamination by major toxins (domoic acid (DA) group, okadaic acid (OA) group and spirolides (SPXs)). Recreational shellfish harvesters had been targeted as an at-risk subpopulation because they consume more shellfish than general population and because they eat not only commercial shellfish species controlled by official authorities but also their own harvests of shellfish species may be in non-controlled areas and more over shellfish species non-considered in the official control species. Then, these two kinds of data were combined with deterministic and probabilistic approaches for both acute and chronic exposures, on considering the impact of shellfish species and cooking on phycotoxin levels. For acute risk, monitoring programs seem to be adequate for DAs, whereas OAs could be a matter of concern for high consumers (their acute intakes were up to ninefold the acute reference dose (ARfD)). About chronic risk, OAs are a matter of concern. The daily OAs intakes were close to the ARfD, which is, by definition, greater than the tolerable daily intake. Moreover, SPX contamination is low but regular, no (sub)chronic SPX toxicity data exist; but in case of (sub)chronic toxicity, SPX exposure should be considered.

  14. Occupational exposure to electromagnetic fields and acute leukaemia: analysis of a case-control study

    PubMed Central

    Willett, E; McKinney, P; Fear, N; Cartwright, R; Roman, E

    2003-01-01

    Aims: To investigate whether the risk of acute leukaemia among adults is associated with occupational exposure to electromagnetic fields. Methods: Probable occupational exposure to electromagnetic fields at higher than typical residential levels was investigated among 764 patients diagnosed with acute leukaemia during 1991–96 and 1510 sex and age matched controls. A job exposure matrix was applied to the self reported employment histories to determine whether or not a subject was exposed to electromagnetic fields. Risks were assessed using conditional logistic regression for a matched analysis. Results: Study subjects considered probably ever exposed to electromagnetic fields at work were not at increased risk of acute leukaemia compared to those considered never exposed. Generally, no associations were observed on stratification by sex, leukaemia subtype, number of years since exposure stopped, or occupation; there was no evidence of a dose-response effect using increasing number of years exposed. However, relative to women considered never exposed, a significant excess of acute lymphoblastic leukaemia was observed among women probably exposed to electromagnetic fields at work that remained increased irrespective of time prior to diagnosis or job ever held. Conclusion: This large population based case-control study found little evidence to support an association between occupational exposure to electromagnetic fields and acute leukaemia. While an excess of acute lymphoblastic leukaemia among women was observed, it is unlikely that occupational exposure to electromagnetic fields was responsible, given that increased risks remained during periods when exposure above background levels was improbable. PMID:12883018

  15. Assessment of dietary exposure and effect in humans: The role of NMR.

    PubMed

    van Duynhoven, John P M; Jacobs, Doris M

    2016-08-01

    In human nutritional science progress has always depended strongly on analytical measurements for establishing relationships between diet and health. This field has undergone significant changes as a result of the development of NMR and mass spectrometry methods for large scale detection, identification and quantification of metabolites in body fluids. This has allowed systematic studies of the metabolic fingerprints that biological processes leave behind, and has become the research field of metabolomics. As a metabolic profiling technique, NMR is at its best when its unbiased nature, linearity and reproducibility are exploited in well-controlled nutritional intervention and cross-sectional population screening studies. Although its sensitivity is less good than that of mass spectrometry, NMR has maintained a strong position in metabolomics through implementation of standardisation protocols, hyphenation with mass spectrometry and chromatographic techniques, accurate quantification and spectral deconvolution approaches, and high-throughput automation. Thus, NMR-based metabolomics has contributed uniquely to new insights into dietary exposure, in particular by unravelling the metabolic fates of phytochemicals and the discovery of dietary intake markers. NMR profiling has also contributed to the understanding of the subtle effects of diet on central metabolism and lipoprotein metabolism. In order to hold its ground in nutritional metabolomics, NMR will need to step up its performance in sensitivity and resolution; the most promising routes forward are the analytical use of dynamic nuclear polarisation and developments in microcoil construction and automated fractionation.

  16. Public health benefits of hair-mercury analysis and dietary advice in lowering methylmercury exposure in pregnant women.

    PubMed

    Kirk, Line E; Jørgensen, Jan S; Nielsen, Flemming; Grandjean, Philippe

    2017-06-01

    To evaluate whether a public health intervention using focused dietary advice combined with a hair-mercury analysis can lower neurotoxic methylmercury exposure among pregnant women without decreasing their overall intake of seafood. A total of 146 pregnant women were consecutively recruited from the antenatal clinic at a Danish university hospital at their initial ultrasound scan. Dietary advice was provided on avoiding methylmercury exposure from large predatory fish and a hair sample from each participant was analysed for mercury, with the results being communicated shortly thereafter to the women. A dietary questionnaire was filled in. Follow-up three months later included a dietary questionnaire and a repeat hair-mercury analysis. In the follow-up group, 22% of the women had hair-mercury concentrations above a safe limit of 0.58 µg/g at enrolment, decreasing to 8% three months later. Average hair-mercury concentrations decreased by 21%. However, the total seafood intake remained at the same level after three months. Increased exposure to methylmercury among pregnant women is an important public health concern in Denmark. The observed lowering of hair-mercury concentrations associated with dietary advice corresponds to a substantial public health benefit that probably makes such an intervention highly profitable.

  17. Chronic vs. Short-Term Acute O 3 Exposure Effects on Nocturnal Transpiration in Two Californian Oaks

    Treesearch

    Nancy Grulke; E. Paoletti; R. L. Heath

    2007-01-01

    We tested the effect of daytime chronic moderate ozone (O3) exposure, short-term acute exposure, and both chronic and acute O3 exposure combined on nocturnal transpiration in California black oak and blue oak seedlings. Chronic O3 exposure (70 ppb for 8 h/day) was implemented in open-top chambers for...

  18. Design, development and validation of software for modelling dietary exposure to food chemicals and nutrients.

    PubMed

    McNamara, C; Naddy, B; Rohan, D; Sexton, J

    2003-10-01

    The Monte Carlo computational system for stochastic modelling of dietary exposure to food chemicals and nutrients is presented. This system was developed through a European Commission-funded research project. It is accessible as a Web-based application service. The system allows and supports very significant complexity in the data sets used as the model input, but provides a simple, general purpose, linear kernel for model evaluation. Specific features of the system include the ability to enter (arbitrarily) complex mathematical or probabilistic expressions at each and every input data field, automatic bootstrapping on subjects and on subject food intake diaries, and custom kernels to apply brand information such as market share and loyalty to the calculation of food and chemical intake.

  19. Dietary exposure and human risk assessment of phthalate esters based on total diet study in Cambodia.

    PubMed

    Cheng, Zhang; Li, Han-Han; Wang, Hong-Sheng; Zhu, Xue-Mei; Sthiannopkao, Suthipong; Kim, Kyoung-Woong; Yasin, Mohamed Salleh Mohamed; Hashim, Jamal Hisham; Wong, Ming-Hung

    2016-10-01

    Phthalate esters are used in a wide variety of consumer products, and human exposure to this class of compounds is widespread. Nevertheless, studies on dietary exposure of human to phthalates are limited. In this study, to assess the daily intakes of phthalate esters and the possible adverse health impacts, different food samples were collected from three areas of Cambodia, one of the poorest countries in the world. The ∑phthalate ester concentrations in Kampong Cham, Kratie and Kandal provinces ranged from 0.05 to 2.34 (median 0.88) μgg(-1), 0.19-1.65 (median 0.86) μgg(-1) and 0.24-3.05 (median 0.59) μgg(-1) wet weight (ww), respectively. Di-2-Ethylhexyl phthalate (DEHP) and diisobutyl phthalate (DiBP) were the predominant compounds among all foodstuffs. The estimated daily intake (EDI) of phthalate esters for the general population in Kampong Cham, Kratie and Kandal was 34.3, 35.6 and 35.8μgkg(-1) bw d(-1), respectively. The dietary daily intake of DEHP, benzylbutyl phthalate (BBP) and di-n-butyl phthalate (DBP) in Kampong Cham, Kratie and Kandal were below the tolerable daily intakes (TDI) imposed by the European Food Safety Authority (EFSA) and reference doses (RfD) imposed by The United States Environmental Protection Agency (USEPA). Rice contributed the greatest quantity of DEHP to the daily intake in Cambodia so may deserve further exploration. To our knowledge, this is the first study to investigate the occurrence and the daily intakes of phthalate esters in Cambodia. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Dietary exposure to persistent organic pollutants and metals among Inuit and Chukchi in Russian Arctic Chukotka

    PubMed Central

    Dudarev, Alexey A.

    2012-01-01

    Objectives The general aim was to assess dietary exposure to selected persistent organic pollutants (POPs) and metals among Eskimo (Inuit) and Chukchi of the Chukotka Peninsula of the Russian Arctic, and to establish recommendations for exposure risk reduction. Study design A cross-sectional evaluation of nutritional patterns of coastal and inland indigenous peoples of the Chukotka Autonomous Okrug (in 2001–2003); assessment of the levels of persistent toxic substances (PTSs) in traditional foods and their comparison to Russian food safety limits; the identification of local sources of food contamination; and the recommendation and implementation of risk management measures. Methods Community-based dietary survey of self reported food frequencies (453 persons), chemical analyses (POPs and metals) of local foods and indoor matters (397 samples), substantiation of recommendations for daily (weekly, monthly) intakes of traditional food. Results POPs in traditional food items are generally below the Russian food safety limits except marine mammal fat, while Hg and Cd are high mainly in mammal viscera. Lead is relatively low in tissues of all animals studied. For the Chukotka coastal communities, seals constitute the principal source of the whole suite of PTSs considered. Consumption restrictions are recommended for marine and freshwater fish, some wild meats (waterfowl and seal), fats (whale and seal), liver (most animals) and kidney (reindeer, walrus and seal). Evidence is presented that contamination of foodstuffs may be significantly increased during storing/processing/cooking of food due to indoor and outdoor environmental conditions. Conclusions Based on the analytical findings and the local PTSs sources identified, guidelines on food safety are suggested, as well as measures to reduce food contamination and domestic and local sources. Important and urgent remedial actions are recommended to minimize PTSs environmental and domestic contamination. Waste clean

  1. Infant dietary exposure to dioxins and dioxin-like compounds in Greece.

    PubMed

    Costopoulou, Danae; Vassiliadou, Irene; Leondiadis, Leondios

    2013-09-01

    The dietary exposure of infants to polychlorinated dibenzo dioxins and furans (PCDD/Fs) and dioxin like polychlorinated biphenyls (dl-PCBs) is an issue of great social impact. We investigated for the first time the dietary intake of these compounds in infants living in Greece. We included in our study two age groups: 0-6 months, when infants are fed exclusively by human milk and/or formula milk, and 6 to 12 months, when solid food is introduced to nutrition. We took into consideration analytical results for PCDD/Fs and dl-PCBs concentrations in the most popular infant formulae in the Greek market, previous data for mother milk concentrations of PCDD/Fs and dl-PCBs from Greece, and finally analytical data for fat-containing food products from the Greek market. In the first study group, it was found than in infants exclusively fed by breast milk, the calculated sum of PCDD/Fs and dioxin-like PCBs (60.3-80.4 TEQ pg/kg body weight) was significantly higher than that of infants that consume a combination of human milk and formula (31.2-41.6 TEQ pg/kg body weight). In the second study group, separate daily intake estimations were performed for babies receiving human milk (estimated total daily intake 19.76-24.95 TEQ pg/kg body weight) and formula milk (estimated total daily intake 1.60-2.24 TEQ pg/kg body weight). The risks of this exposure should not be overestimated because nursing is restricted to a limited period of human life and besides, the potential consumption of higher levels of dioxin-like compounds is fully compensated by the significant benefits of breast-feeding. Copyright © 2013 Elsevier Ltd. All rights reserved.

  2. Steroids in marine aquaculture farms surrounding Hailing Island, South China: occurrence, bioconcentration, and human dietary exposure.

    PubMed

    Liu, Shan; Chen, Hui; Xu, Xiang-Rong; Liu, Shuang-Shuang; Sun, Kai-Feng; Zhao, Jian-Liang; Ying, Guang-Guo

    2015-01-01

    The occurrence, bioconcentration, and human dietary exposure via seafood consumption of 24 steroids were investigated by rapid resolution liquid chromatography-tandem mass spectrometry (RRLC-MS/MS) in six typical marine aquaculture farms surrounding Hailing Island, South China. Ten, 9, 10, 15 of 24 steroids were detected at concentrations ranging from <0.1 (testosterone) to 40 ng/L (prednisolone), from 0.1 (4-androstene-3,17-dione) to 2.4 ng/g (progesterone), from 0.3 ng/g (testosterone) to 21.4 ng/g (epi-androsterone), and from <0.1 (testosterone) to 560 ng/g (cortisol) (wet weight) in the water, sediment, feed and biota samples, respectively. Synthetic steroids (androsta-1,4-diene-3,17-dione, 17α-boldenone, 17β-boldenone, 17β-trenbolone, prednisolone, norgestrel) were detected in the feed samples, clearly demonstrating the illegal use of steroids in the feed. The field bioconcentration factors (BCFs) of steroids calculated in different aquatic organisms ranged from 93.8 to 4000. The estimated daily intakes (EDIs) of androgens, glucocorticoids, and progestagens via consumption of seafood (i.e., shrimps, crabs, mollusks, and fish) for different age groups were in the range of 33.4-134, 2061-8566, and 40.4-155 ng/d for children (2-5 years), youth (6-18 years), and adults (>18 years), respectively. Even though no significant risk from dietary exposure arises from individual steroid, elevated risk to humans can result from the occurrence of multiple steroids in the seafood raised in the aquaculture farms, especially for the sensitive populations, such as pregnant women and children.

  3. Hexabromocyclododecane (HBCD) in the Korean food basket and estimation of dietary exposure.

    PubMed

    Barghi, Mandana; Shin, Eun-Su; Son, Min-Hui; Choi, Sung-Deuk; Pyo, Heesoo; Chang, Yoon-Seok

    2016-06-01

    1,2,5,6,9,10-hexabromocyclododecane (HBCD) is a brominated flame retardant that is used worldwide in expanded and extruded polystyrene foam and simultaneously emitted to the environment. HBCD can easily accumulate in animals and humans and cause neurotoxicity, thyroid hormone disruption, and reproductive disorders. Therefore, it is essential to monitor the HBCD concentrations in foods and estimate the human exposure through the diet. In this study a total of 521 food samples from eight food categories were sampled and analyzed for their HBCD content. Based on consumption data, the average dietary intake of the general Korean population and specific subgroups was calculated. The highest levels of HBCD were found in fish and shellfish (0.47 ng g(-1) ww), and this was attributed to natural exposure to the contaminated marine environments and the HBCD bioaccumulation. In addition, the use of expanded polystyrene buoys in aquaculture was also found to be a potential source of HBCD in bivalves. The high solubility of α-HBCD in water and the persistence of this diastereomer compared to β- and γ-HBCD in biological tissues, led to higher accumulation of α-HBCD in animal-based foods. In contrast, the diastereomeric selectivity and lower metabolic capacity in plants compared with animals led to the predominance of γ-HBCD in plant-based foods. The dietary intake of HBCD was estimated to be 0.82 ng kg(-1) bw d(-1) in the general population and 2.89 ng kg(-1) bw d(-1) in children up to 5 years of age. The high HBCD intake in children was found to be a result of their lower body weight and their high consumption of milk and homemade Korean baby foods that usually contain fish.

  4. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    EPA Science Inventory

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  5. ESTIMATED RATE OF FATAL AUTOMOBILE ACCIDENTS ATTRIBUTABLE TO ACUTE SOLVENT EXPOSURE AT LOW INHALED CONCENTRATIONS

    EPA Science Inventory

    Acute solvent exposures may contribute to automobile accidents because they increase reaction time and decrease attention, in addition to impairing other behaviors. These effects resemble those of ethanol consumption, both with respect to behavioral effects and neurological mecha...

  6. Multigenerational exposure to dietary nonylphenol has no severe effects on spatial learning in female rats.

    PubMed

    Flynn, Katherine M; Newbold, Retha R; Ferguson, Sherry A

    2002-05-01

    Nonylphenol is a common intermediate in the production of many consumer compounds and reportedly acts as an estrogen mimic. Because estrogen affects the spatial learning and memory in rats, the effects of nonylphenol exposure on the performance of female rats in the Morris water maze were investigated. Here, Sprague-Dawley rats (F0) consumed soy-free diets containing 0, 25, 200 or 750 ppm nonylphenol (0, 2, 16 or 60 mg/kg per day) beginning on postnatal day (PND) 42 and continuing for two generations (F1 and F2) with breeding occurring within treatments. Females to be behaviorally tested (n = 7-8 per treatment per generation) were ovariectomized at adulthood and assessed for spatial learning and memory between PND 125-150 (young adult age). Each rat was tested for four consecutive days (three trials per day) in the Morris water maze with the platform in a fixed location. One week later, each subject was primed with estrogen and progesterone and assessed on a single day (three trials). The F1 rats continued on the same diets until PND 380-395 (middle aged) when they were re-tested as above (four consecutive days followed 1 week later with hormonal priming and a single test day). Latency to find the platform, path length and swim speed were averaged over the three trials per day and analyzed using repeated measures analyses of variance. There were no consistent effects of dietary nonylphenol exposure and no interactions of nonylphenol exposure on any measure of performance in either generation at the young age nor at the middle age in the F1 generation. When tested at the young adult age, however, hormone priming resulted in latencies and path lengths that were significantly shorter than in those exhibited during the unprimed test days, and there was no such effect when tested at middle age. Middle aged rats exhibited better performance than the same animals tested at a young age, likely as a result of familiarity and practice with the test paradigm. These data

  7. Dietary Cadmium Exposure and Risk of Breast, Endometrial, and Ovarian Cancer in the Women’s Health Initiative

    PubMed Central

    Quraishi, Sabah M.; Shafer, Martin M.; Passarelli, Michael N.; Freney, Emily P.; Chlebowski, Rowan T.; Luo, Juhua; Meliker, Jaymie R.; Mu, Lina; Neuhouser, Marian L.; Newcomb, Polly A.

    2014-01-01

    Background: In vitro and animal data suggest that cadmium, a heavy metal that contaminates some foods and tobacco plants, is an estrogenic endocrine disruptor. Elevated estrogen exposure is associated with breast, endometrial, and ovarian cancer risk. Objectives: We examined the association between dietary cadmium intake and risk of these cancers in the large, well-characterized Women’s Health Initiative (WHI). Methods: A total of 155,069 postmenopausal women, 50–79 years of age, who were enrolled in the WHI clinical trials or observational study, participated in this study. We estimated dietary cadmium consumption by combining baseline food frequency questionnaire responses with U.S. Food and Drug Administration data on food cadmium content. Participants reported incident invasive breast, endometrial, or ovarian cancer, and WHI centrally adjudicated all cases through August 2009. We applied Cox regression to estimate adjusted hazard ratios (HRs) and 95% CIs for each cancer, comparing quintiles of energy-adjusted dietary cadmium intake. Results: Over an average of 10.5 years, 6,658 invasive breast cancers, 1,198 endometrial cancers, and 735 ovarian cancers were reported. We observed no statistically significant associations between dietary cadmium and risk of any of these cancers after adjustment for potential confounders including total dietary energy intake. Results did not differ in any subgroup of women examined. Conclusions: We found little evidence that dietary cadmium is a risk factor for breast, endometrial, or ovarian cancers in postmenopausal women. Misclassification in dietary cadmium assessment may have attenuated observed associations. Citation: Adams SV, Quraishi SM, Shafer MM, Passarelli MN, Freney EP, Chlebowski RT, Luo J, Meliker JR, Mu L, Neuhouser ML, Newcomb PA. 2014. Dietary cadmium exposure and risk of breast, endometrial, and ovarian cancer in the Women’s Health Initiative. Environ Health Perspect 122:594–600; http://dx.doi.org/10

  8. SPECIES SPECIFIC DIETARY ARSENIC EXPOSURE ASSESSMENT: THE NEED TO ESTIMATE BIOACCESSIBILITY AND ASSESSING THE IMPLIED PRESYSTEMIC METABOLISM IMPLICATIONS

    EPA Science Inventory

    The chemical form specific toxicity of arsenic dictates the need for species specific quantification in order to accurately assess the risk from an exposure. The literature has begun to produce preliminary species specific databases for certain dietary sources, but a quantitativ...

  9. MODELED RESIDENTIAL CHLORPYRIFOS EXPOSURE AND DOSE TO CHILDREN VIA DERMAL SURFACE RESIDUE CONTACT AND NON-DIETARY INGESTION

    EPA Science Inventory

    A physically-based stochastic model has been applied to estimate residential chlorpyrifos exposure and dace to children via the non-dietary ingestion and dermal residue contact pathways. Time-location-activity data for 2825 children were sampled from national surveys to generat...

  10. SPECIES SPECIFIC DIETARY ARSENIC EXPOSURE ASSESSMENT: THE NEED TO ESTIMATE BIOACCESSIBILITY AND ASSESSING THE IMPLIED PRESYSTEMIC METABOLISM IMPLICATIONS

    EPA Science Inventory

    The chemical form specific toxicity of arsenic dictates the need for species specific quantification in order to accurately assess the risk from an exposure. The literature has begun to produce preliminary species specific databases for certain dietary sources, but a quantitativ...

  11. Dietary predictors of young children’s exposures to chlorpyrifos, permethrin, and 2,4-D using urinary biomonitoring

    EPA Science Inventory

    Few data exist on the association between dietary habits and urinary biomarker concentrations of pesticides in children. The objective was to examined the association between the weekly intake frequency of 65 food items and urinary biomarkers of exposure to chlorpyrifos (3,5,6-tr...

  12. MODELED RESIDENTIAL CHLORPYRIFOS EXPOSURE AND DOSE TO CHILDREN VIA DERMAL SURFACE RESIDUE CONTACT AND NON-DIETARY INGESTION

    EPA Science Inventory

    A physically-based stochastic model has been applied to estimate residential chlorpyrifos exposure and dace to children via the non-dietary ingestion and dermal residue contact pathways. Time-location-activity data for 2825 children were sampled from national surveys to generat...

  13. Dietary predictors of young children’s exposures to chlorpyrifos, permethrin, and 2,4-D using urinary biomonitoring

    EPA Science Inventory

    Few data exist on the association between dietary habits and urinary biomarker concentrations of pesticides in children. The objective was to examined the association between the weekly intake frequency of 65 food items and urinary biomarkers of exposure to chlorpyrifos (3,5,6-tr...

  14. [Current dietary exposure to mercury during pregnancy and childhood, and public health recommendations].

    PubMed

    Llop, Sabrina; Ibarlucea, Jesús; Sunyer, Jordi; Ballester, Ferran

    2013-01-01

    Exposure to high levels of mercury during vulnerable periods (such as pregnancy and childhood) may have serious consequences for cognitive development, as observed after acute poisoning episodes in Japan and Irak. The main source of mercury exposure in the general population is consumption of certain types of fish. There is growing concern about the possible neurotoxic effects of mercury, especially in younger children in populations where fish intake is moderate to high. The scientific evidence to date is inconclusive. In Spain, the Childhood and Environment (Infancia y Medio Ambiente [INMA]) project has provided information on levels of prenatal exposure to mercury among 1800 newborns from Valencia, Sabadell, Asturias and Guipúzcoa. In general, levels were high, being above the World Health Organization's recommended dose in 24% of children and above the recommended levels of the U.S. Environmental Protection Agency in 64%. However, the results did not indicate a significant association between prenatal mercury exposure and delayed cognitive development during the second year of life. Various agencies have developed recommendations on fish consumption for pregnant women and children, due to the presence of mercury. These recommendations should be strengthened, since there is general consensus among all regional and national public administrations that fish is an essential source of nutrients for development in the early stages of life.

  15. Chronic dietary exposure to environmental organochlorine contaminants induces thyroid gland lesions in Arctic foxes (Vulpes lagopus).

    PubMed

    Sonne, Christian; Wolkers, Hans; Leifsson, Pall S; Iburg, Tine; Jenssen, Bjørn Munro; Fuglei, Eva; Ahlstrøm, Oystein; Dietz, Rune; Kirkegaard, Maja; Muir, Derek C G; Jørgensen, Even H

    2009-08-01

    The impact of dietary organochlorine (OC) exposure on thyroid gland pathology was studied in farmed male Arctic foxes (Vulpes lagopus). The exposed group (n=16) was fed a diet based on wild minke whale (Balaenoptera acutorostrata) blubber as a main fat source in order to mimic the exposure to OC cocktails in the Artic environment. This resulted in an exposure of approximately 17 microg Sigma OC/kg day and a Sigma OC residue adipose tissue and liver concentration of 1700 and 4470 ng/gl.w., respectively, after 16 months of exposure. Control foxes (n=13) were fed a diet with pork (Sus scrofa) fat as a main fat source containing significantly lower OC concentrations. The food composition fed to the control and exposed group was standardized for nutrient contents. Four OC-related histopathological changes were found: (1) flat-epithelial-cell true thyroid cysts (TC) characterized by neutral content; (2) remnants of simple squamous epithelial-cell embryonic ducts containing neutral debris (EDN); (3) remnants of stratified squamous epithelial-cell embryonic ducts containing acid mucins often accompanied with debris of leukocyte inflammatory nature (EDM) and (4) disseminated thyroid C-cell hyperplasia (HPC). Of these, the prevalence of TC, EDN and HPC was significantly highest in the exposed group (chi(2) test: all p<0.04). The study shows that the OC mixture in minke whale blubber may cause development of thyroid gland cysts, C-cell hyperplasia and increase the prevalence of cystic remnants of embryonic ducts. The mechanism causing these effects could include endocrine disruption of the hypothalamus-pituitary-thyroid (HPT) axis, a disturbance of the calcium homeostasis/metabolism or energy metabolism or immune suppression. Because concentrations of OCs are higher in wild Arctic foxes, it is likely that these animals could suffer from similar OC-induced thyroid gland pathological and functional changes.

  16. Energetic cost of dietary exposure to polychlorinated biphenyls (PCBS) for white-footed mice, Peromyscus leucopus

    USGS Publications Warehouse

    Voltura, M.B.; French, J.B.

    1998-01-01

    Contaminant exposure is an environmental factor often overlooked in ecological studies. Yet exposure to toxicants is likely to be metabolically expensive, and result in a trade-off between energy spent to detoxify an excrete contaminants, and energy allocated to growth or reproduction. To quantify the energetic cost of PCB exposure, we fed mice diets containing 0, 0.1, 10 and 25 ppm PCBs (mg PCBs/kg food). After 6 wks, there were no differences in food intake or body mass related to the level of dietary PCBs. We continued to feed mice the PCB diets for one year, and then measured food intake and resting metabolic rate. After one year, all mice had gained mass, but mice on the 25 ppm diet were significantly heavier than mice in the other groups. Mice on the 25 ppm diet also showed an increase in both food intake (p=0.06) and metabolic rate (p=0.01), after correction for differences in body mass. Food intake averaged 4.1 g/d for mice on the 25 ppm diet, compared to 3.7 gld for control mice. Oxygen consumption at 30°C averaged 40.1 ml O2/h for mice on the 25 ppm diet, compared to 36.6 ml O2/h for control mice. These results show that for white-footed mice, there is an energetic cost to contaminant exposure that when combined with other environmental stresses, will influence patterns of energy acquisition and allocation.

  17. Comparison of Acute Health Effects From Exposures to Diesel and Biodiesel Fuel Emissions

    PubMed Central

    Mehus, Aaron A.; Reed, Rustin J.; Lee, Vivien S. T.; Littau, Sally R.; Hu, Chengcheng; Lutz, Eric A.

    2015-01-01

    Objective: To investigate the comparative acute health effects associated with exposures to diesel and 75% biodiesel/25% diesel (B75) blend fuel emissions. Methods: We analyzed multiple health endpoints in 48 healthy adults before and after exposures to diesel and B75 emissions in an underground mine setting—lung function, lung and systemic inflammation, novel biomarkers of exposure, and oxidative stress were assessed. Results: B75 reduced respirable diesel particulate matter by 20%. Lung function declined significantly more after exposure to diesel emissions. Lung inflammatory cells along with sputum and plasma inflammatory mediators increased significantly to similar levels with both exposures. Urinary 8-hydroxydeoxyguanosine, a marker of oxidative stress, was not significantly changed after either exposure. Conclusions: Use of B75 lowered respirable diesel particulate matter exposure and some associated acute health effects, although lung and systemic inflammation were not reduced compared with diesel use. PMID:26147538

  18. Comparison of Acute Health Effects From Exposures to Diesel and Biodiesel Fuel Emissions.

    PubMed

    Mehus, Aaron A; Reed, Rustin J; Lee, Vivien S T; Littau, Sally R; Hu, Chengcheng; Lutz, Eric A; Burgess, Jefferey L

    2015-07-01

    To investigate the comparative acute health effects associated with exposures to diesel and 75% biodiesel/25% diesel (B75) blend fuel emissions. We analyzed multiple health endpoints in 48 healthy adults before and after exposures to diesel and B75 emissions in an underground mine setting-lung function, lung and systemic inflammation, novel biomarkers of exposure, and oxidative stress were assessed. B75 reduced respirable diesel particulate matter by 20%. Lung function declined significantly more after exposure to diesel emissions. Lung inflammatory cells along with sputum and plasma inflammatory mediators increased significantly to similar levels with both exposures. Urinary 8-hydroxydeoxyguanosine, a marker of oxidative stress, was not significantly changed after either exposure. Use of B75 lowered respirable diesel particulate matter exposure and some associated acute health effects, although lung and systemic inflammation were not reduced compared with diesel use.

  19. Dietary exposure of Hong Kong adults to pesticide residues: results of the first Hong Kong Total Diet Study.

    PubMed

    Wong, Waiky W K; Yau, Arthur T C; Chung, Stephen W C; Lam, Chi-ho; Ma, Stephanie; Ho, Y Y; Xiao, Ying

    2014-01-01

    The use of pesticides and other chemicals has become a common practice in modern agriculture to enhance and stabilise crop yield, protect the nutritional integrity of food, facilitate food storage to assure year-round supplies, and provide attractive and appealing food products. With the adoption of strict good agricultural practice (GAP), only minimal amounts of pesticide residues should remain on the crops or in connected foods of animal origin up the food chain. To assess their associated health risk to local people, the dietary exposure of Hong Kong adults to residues of four groups of pesticides or their metabolites - organophosphorus pesticides (OPPs), carbamates, pyrethrins and pyrethroids, and dithiocarbamate (DTC) metabolites - is estimated in the first Hong Kong Total Diet Study (TDS). A total of 150 commonly consumed food items were collected and prepared "as consumed". A total of 600 composite food samples were analysed for 85 pesticides or their metabolites by liquid chromatography-tandem mass spectrometry (LC-MS/MS). These pesticides were primarily found at low levels (highest mean = 350 μg kg⁻¹) in food samples of plant origin such as vegetables and fruits. Dietary exposures to pesticide residues were estimated based on the analytical results and the food consumption data of the local residents. The estimated dietary exposures of Hong Kong adults to all individual pesticides were well below their respective acceptable daily intakes (ADIs). The percentage contributions of the estimated mean and 95th percentile dietary exposures to the ADIs of individual pesticides were <6% and <24% for the OPPs, <1% for the carbamates and pyrethrins and pyrethroids, and <1% and <4% for the DTC metabolites, respectively. The findings indicate that dietary exposures to all the pesticide residues analysed in this study were unlikely to pose unacceptable health risks to the Hong Kong population.

  20. Risk assessment of the cumulative acute exposure of Hungarian population to organophosphorus pesticide residues with regard to consumers of plant based foods.

    PubMed

    Zentai, Andrea; Szabó, István J; Kerekes, Kata; Ambrus, Árpád

    2016-03-01

    Based on the Hungarian pesticide residues monitoring data of the last five years and the consumption data collected within a 3-day dietary record survey in 2009 (more than 2 million pesticide residue results and almost 5000, 0-101-year-old consumers 3 non-consecutive-day personal fruit and vegetable consumption data), the cumulative acute exposure of organophosphorus pesticide residues was evaluated. The relative potency factor approach was applied, with acephate chosen as index compound. According to our conservative calculation method, applying the measured residues only, the 99.95% of the 99th percentiles of calculated daily intakes was at or below 87 μg/kgbwday, indicating that the cumulative acute exposure of the whole Hungarian population (including all age classes) to organophosphorus compounds was not a health concern.

  1. Acute dietary zinc deficiency before conception compromises oocyte epigenetic programming and disrupts embryonic development

    PubMed Central

    Tian, X; Diaz, FJ

    2013-01-01

    Recent findings show that zinc is an important factor necessary for regulating the meiotic cell cycle and ovulation. However, the role of zinc in promoting oocyte quality and developmental potential is not known. Using an in vivo model of acute dietary zinc deficiency, we show that feeding a zinc deficient diet (ZDD) for 3–5 days before ovulation (preconception) dramatically disrupts oocyte chromatin methylation and preimplantation development. There was a dramatic decrease in histone H3K4 trimethylation and global DNA methylation in zinc deficient oocytes. Moreover, there was a 3–20 fold increase in transcript abundance of repetitive elements (Iap, Line1, Sineb1, Sineb2), but a decrease in Gdf9, Zp3 and Figla mRNA. Only 53% and 8% of mature eggs reached the 2-cell stage after IVF in animals receiving a 3 and 5 day ZDD, respectively, while a 5 day ZDD in vivo reduced the proportion of 2-cells to 49%. In vivo fertilized 2-cell embryos cultured in vitro formed fewer (38%) blastocysts compared to control embryos (74%). Likewise, fewer blastocyst and expanded blastocyst were collected from the reproductive tract of zinc deficient animals on day 3.5 of pregnancy. This could be due to a decrease in Igf2 and H19 mRNA in ZDD blastocyst. Supplementation with a methyl donor (SAM) during IVM restored histone H3K4me3 and doubled the IVF success rate from 17% to 43% in oocytes from zinc deficient animals. Thus, the terminal period of oocyte development is extremely sensitive to perturbation in dietary zinc availability. PMID:23348678

  2. A novel approach reveals that zinc oxide nanoparticles are bioavailable and toxic after dietary exposures

    USGS Publications Warehouse

    Croteau, M.-N.; Dybowska, A.D.; Luoma, S.N.; Valsami-Jones, E.

    2011-01-01

    If engineered nanomaterials are released into the environment, some are likely to end up associated with the food of animals due to aggregation and sorption processes. However, few studies have considered dietary exposure of nanomaterials. Here we show that zinc (Zn) from isotopically modified 67ZnO particles is efficiently assimilated by freshwater snails when ingested with food. The 67Zn from nano-sized 67ZnO appears as bioavailable as 67Zn internalized by diatoms. Apparent agglomeration of the zinc oxide (ZnO) particles did not reduce bioavailability, nor preclude toxicity. In the diet, ZnO nanoparticles damage digestion: snails ate less, defecated less and inefficiently processed the ingested food when exposed to high concentrations of ZnO. It was not clear whether the toxicity was due to the high Zn dose achieved with nanoparticles or to the ZnO nanoparticles themselves. Further study of exposure from nanoparticles in food would greatly benefit assessment of ecological and human health risks. ?? 2011 Informa UK, Ltd.

  3. Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay.

    PubMed

    Casazza, Michael L; Ricca, Mark A; Overton, Cory T; Takekawa, John Y; Merritt, Angela M; Ackerman, Joshua T

    2014-09-15

    California Clapper Rails (Rallus longirostris obsoletus) are an endangered waterbird that forage in tidal-marsh habitats that pose risks from mercury exposure. We analyzed total mercury (Hg) in six macro-invertebrate and one fish species representing Clapper Rail diets from four tidal-marshes in San Francisco Bay, California. Mercury concentrations among individual taxa ranged from lowest at Colma Creek (mean range: 0.09-0.2 μg/g dw) to highest at Cogswell (0.2-0.7), Laumeister (0.2-0.9) and Arrowhead Marshes (0.3-1.9). These spatial patterns for Hg matched patterns reported previously in Clapper Rail blood from the same four marshes. Over 25% of eastern mudsnails (Ilyanassa obsolete) and staghorn sculpin (Leptocottus armatus) exceeded dietary Hg concentrations (ww) often associated with avian reproductive impairment. Our results indicate that Hg concentrations vary considerably among tidal-marshes and diet taxa, and Hg concentrations of prey may provide an appropriate proxy for relative exposure risk for Clapper Rails.

  4. Effects of dietary PCB exposure on adrenocortical function in captive American kestrels (Falco sparverius).

    PubMed

    Love, Oliver P; Shutt, Laird J; Silfies, Joel S; Bortolotti, Gary R; Smits, Judit E G; Bird, David M

    2003-01-01

    We experimentally examined the effects of dietary exposure to polychlorinated biphenyls (PCBs) on adrenocortical function in American kestrels (Falco sparverius). Nine captive male American kestrels previously exposed to a PCB mixture (Aroclor 1248:1254:1260; 1:1:1) in their diet were subjected to a standardized capture, handling and restraint protocol designed to produce an increase in circulating corticosterone. A similar protocol has been applied to a wide range of avian species and was used here to evaluate the response of PCB-exposed and control kestrels to a defined physical stressor. Both baseline and stress-induced corticosterone levels were significantly lower in PCB-exposed birds when compared with control birds of the same age. PCB-exposed birds exhibited significantly lower corticosterone levels during the corticosterone response when compared with control birds, independent of body condition. Furthermore, baseline corticosterone concentrations exhibited a hormetic response characterized by an inverted U-shaped dose response in relation to total PCB liver burden. These results support several recent studies which report decreased levels of circulating corticosterone in PCB-exposed wild birds. The results presented here provide the first evidence that exposure to an environmentally relevant level of PCBs (approximately 10 mg/kg body weight) can impair the corticosterone stress response in kestrels, potentially increasing the susceptibility of birds to environmental stressors such as severe weather and predatory and human disturbance.

  5. Dietary mercury exposure to endangered California Clapper Rails in San Francisco Bay

    USGS Publications Warehouse

    Casazza, Michael L.; Ricca, Mark A.; Overton, Cory T.; Takekawa, John Y.; Merritt, Angela M.; Ackerman, Joshua T.

    2015-01-01

    California Clapper Rails (Rallus longirostris obsoletus) are an endangered waterbird that forage in tidal-marsh habitats that pose risks from mercury exposure. We analyzed total mercury (Hg) in six macro-invertebrate and one fish species representing Clapper Rail diets from four tidal-marshes in San Francisco Bay, California. Mercury concentrations among individual taxa ranged from lowest at Colma Creek (mean range: 0.09–0.2 μg/g dw) to highest at Cogswell (0.2–0.7), Laumeister (0.2–0.9) and Arrowhead Marshes (0.3–1.9). These spatial patterns for Hg matched patterns reported previously in Clapper Rail blood from the same four marshes. Over 25% of eastern mudsnails (Ilyanassa obsolete) and staghorn sculpin (Leptocottus armatus) exceeded dietary Hg concentrations (ww) often associated with avian reproductive impairment. Our results indicate that Hg concentrations vary considerably among tidal-marshes and diet taxa, and Hg concentrations of prey may provide an appropriate proxy for relative exposure risk for Clapper Rails.

  6. Bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure.

    PubMed

    Lv, Xiaotian; Liu, Chen; Li, Yaobin; Gao, Yongxin; Guo, Baoyuan; Wang, Huili; Li, Jianzhong

    2013-12-01

    The bioaccumulation and excretion of enantiomers of myclobutanil in Tenebrio molitor larvae through dietary exposure under laboratory conditions were investigated using high-performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS) based on a ChiralcelOD-3R [cellulosetris-tris-(3, 5-dichlorophenyl-carbamate)] column. The wheat bran fed to Tenebrio molitor larvae was spiked with racemic myclobutanil at two dose levels of 20 mg/kg and 2 mg/kg (dry weight). The results showed that there was a significant trend of enantioselective bioaccumulation in the larvae with a preferential accumulation of (-)-myclobutanil in 20 mg/kg dose exposure, but it was not obviously observed in the 2 mg/kg dose group. A kinetic model considering enantiomerization between the two enantiomers based on first-order reactions was built and the rate constants were estimated to discuss the kinetic reason for the different concentrations of individual enantiomers in the larvae. The approximations implied an inversion between the two enantiomers with a relatively higher rate of the inversion from (-)-myclobutanil to (+)-myclobutanil. Meanwhile, analysis of data of excretion samples suggested the active excretion is probably an important pathway for the insect to eliminate myclobutanil rapidly with nonenantioselectivity as a passive transport process, which was consistent with the low accumulation efficiency of myclobutanil measured by BAF (bioaccumulation factor). © 2013 Wiley Periodicals, Inc.

  7. Leaded crystal as a source of dietary lead: An exposure assessment

    SciTech Connect

    Shorten, C.V.; Glowacki, M.L.

    1995-12-31

    Lead is a potent systemic toxic with many environmental sources. It can enter the body through a number of pathways, the most significant is ingestion. While many investigators of lead ingestion have focused on paint and dust sources, the authors examined food contaminated with lead from crystal ware. The rates and amounts of lead leached into vinegar stored in leaded crystal cruets were measured over the course of a 42-day laboratory study. Replicate lead oxide (PbO, 24%) crystal cruets (N = 13) were filled with vinegar, and sample aliquots were periodically removed for analysis. Lead leaching rates were determined by fitting a two-stage, non-linear model to the data, and observed rate coefficients were 0.066 hr{sup {minus}1} and 0.0019{sup {minus}1} for the first and second stages of leaching, respectively (R{sup 2} = 0.9680). Average lead concentrations in the stored vinegar range from 118 {micro}g/L at 8 parameters (ingestion rate, exposure frequency and duration, body weight, and averaging time) was generated to characterize the realm of potential intake estimates. Lead concentrations were input using the fitted model. Results indicated that a worst case lead intake estimate from this source could be as high as 420 {micro}g/kg/yr for a child. Crystal ware can be considered to be a potentially significant dietary source of lead, and risk characterizations cannot ignore this potential avenue when combining risks across all exposure pathways.

  8. Aluminum exposure for 60days at human dietary levels impairs spermatogenesis and sperm quality in rats.

    PubMed

    Martinez, Caroline Silveira; Escobar, Alyne Gourlart; Uranga-Ocio, José Antonio; Peçanha, Franck Maciel; Vassallo, Dalton Valentim; Exley, Christopher; Miguel, Marta; Wiggers, Giulia Alessandra

    2017-08-18

    Concerns about environmental aluminum (Al) and reproductive health have been raised. We investigated the effects of Al exposure at a human relevant dietary level and a high level exposure to Al. Experiment 1 (Lower level) rats were treated orally for 60 days: a) controls - ultrapure water; b) aluminum at 1.5mg/kg bw/day and c) aluminum at 8.3mg/kg bw/day. Experiment 2 (High level) rats were treated for 42 days: a) controls - ultrapure water; b) aluminum at 100mg/kg bw/day. Al decreased sperm count, daily sperm production, sperm motility, normal morphological sperm, impaired testis histology; increased oxidative stress in reproductive organs and inflammation in testis. Our study shows the specific presence of Al in the germinative cells and, that low concentrations of Al in testes (3.35μg/g) are sufficient to impair spermatogenesis and sperm quality. Our findings provide a better understanding of the reproductive health risk of Al. Copyright © 2017 Elsevier Inc. All rights reserved.

  9. Concentrations of phthalates and bisphenol A in Norwegian foods and beverages and estimated dietary exposure in adults.

    PubMed

    Sakhi, Amrit K; Lillegaard, Inger Therese L; Voorspoels, Stefan; Carlsen, Monica H; Løken, Elin B; Brantsæter, Anne L; Haugen, Margaretha; Meltzer, Helle M; Thomsen, Cathrine

    2014-12-01

    Phthalates and bisphenol A (BPA) are ubiquitous in our environment. These chemicals have been characterized as endocrine disruptors that can cause functional impairment of development and reproduction. Processed and packaged foods are among the major sources of human exposure to these chemicals. No previous report showing the levels of these chemicals in food items purchased in Norway is available. The aim of the present study was to determine the concentration of ten different phthalates and BPA in foods and beverages purchased on the Norwegian market and estimate the daily dietary exposure in the Norwegian adult population. Commonly consumed foods and beverages in Norway were purchased in a grocery store and analysed using gas- and liquid chromatography coupled with mass spectrometry. Daily dietary exposures to these chemicals in the Norwegian adult population were estimated using the latest National dietary survey, Norkost 3 (2010-2011). This study showed that phthalates and BPA are found in all foods and beverages that are common to consume in Norway. The detection frequency of phthalates in the food items varied from 11% for dicyclohexyl phthalate (DCHP) to 84% for di-iso-nonyl phthalate (DiNP), one of the substitutes for bis(2-ethylhexyl) phthalate (DEHP). BPA was found in 54% of the food items analysed. Among the different phthalates, the highest concentrations were found for DEHP and DiNP in the food items. Estimated dietary exposures were also equally high and dominated by DEHP and DiNP (400-500 ng/kg body weight (bw)/day), followed by di-iso-butyl phthalate (DiBP), di-n-butyl phthalate (DnBP), di-n-octyl phthalate (DnOP) and di-iso-decyl phthalate (DiDP) (30-40 ng/kg bw/day). Dimethyl phthalate (DMP), diethylphthalate (DEP) and DCHP had the lowest concentrations and the exposures were around 10-20 ng/kg bw/day. Estimated dietary exposure to BPA was 5 ng/kg bw/day. In general, levels of phthalates and BPA in foods and beverages from the Norwegian market

  10. Effects of chronic dietary and waterborne cadmium exposures on the contamination level and reproduction of Daphnia magna.

    PubMed

    Geffard, Olivier; Geffard, Alain; Chaumot, Arnaud; Vollat, Bernard; Alvarez, Cathy; Tusseau-Vuillemin, Marie-Hélène; Garric, Jeanne

    2008-05-01

    Regulatory assessments of metal toxicity on freshwater organisms assume that toxic effects are caused by dissolved metals. In aquatic systems, organisms are exposed to both dissolved and particulate-bound metals. In this study, the chronic toxicity of dietary cadmium (Cd) on the reproduction and Cd body burden of Daphnia magna was investigated. Daphnids (<24 h) were successively exposed to dissolved Cd (8 h) and then to uncontaminated or contaminated algae (16 h) for 21 d. The results show a higher Cd burden in daphnids because of the addition of contaminated food and reveal that Cd uptake by D. magna from water and food was additive for the lowest Cd concentrations tested. Similar Cd distributions (cytosolic and insoluble fractions) were observed in the two groups of organisms, showing similar potential toxicity of Cd accumulated from the two exposure routes. Dietary Cd induces deleterious effects on D. magna reproduction. On the basis of Cd body burden of daphnids, the results support the claim that waterborne and dietary Cd exposures were additive in causing toxicity for Cd concentrations lower than 25 microg/L. At the highest Cd concentrations, the importance of dietary Cd on the daphnid contamination level decreases and confounding factors such as feeding rate reduction seem to appear, which induce an effect on neonate reproduction. In this study, we illustrate the need to take the dietary pathway into account in regulatory assessments and to establish effective concentrations with particulate-bound metals.

  11. Brewing complications: the effect of acute ethanol exposure on wound healing

    PubMed Central

    Radek, Katherine A.; Ranzer, Matthew J.; DiPietro, Luisa A.

    2009-01-01

    Ethanol consumption is linked to a higher incidence of traumatic wounds and increases the risk for morbidity and mortality following surgical or traumatic injury. One of the most profound effects of acute ethanol exposure on wound healing occurs during the inflammatory response, and altered cytokine production is a primary component. Acute ethanol exposure also impairs the proliferative response during healing, causing delays in epithelial coverage, collagen synthesis, and blood vessel regrowth. The accumulated data support the paradigm that acute ethanol intoxication prior to injury significantly diminishes a patient’s ability to heal efficiently. PMID:19675208

  12. Dietary exposure of Hong Kong adults to acrylamide: results of the first Hong Kong Total Diet Study.

    PubMed

    Wong, Waiky W K; Chung, Stephen W C; Lam, Chi-ho; Ho, Y Y; Xiao, Ying

    2014-01-01

    Acrylamide is a processing contaminant in food formed during cooking at high temperature, such as frying and baking. To assess the associated health risk of the Hong Kong population, the dietary exposure of Hong Kong adults to acrylamide was estimated in the first Hong Kong Total Diet Study (TDS), where food samples were collected and prepared "as consumed". A total of 532 composite food samples were analysed for acrylamide using LC-MS/MS. Dietary exposures were estimated by combining the analytical results with the food consumption data of the Hong Kong adults. The mean and 95th percentile exposures to acrylamide of the Hong Kong population were 0.213 and 0.538 μg kg⁻¹ body weight (bw) day⁻¹, respectively, and their margins of exposure (MOEs) were all below 10,000. The main dietary source of acrylamide was "Vegetables and their products" (52.4% of the total exposure), particularly stir-fried vegetables (44.9%), followed by "Cereals and their products" (14.7%) and "Mixed dishes" (9.43%). The study findings suggest that the relatively low figures for MOE for a genotoxic carcinogen may indicate human health concern of the Hong Kong population. Efforts should continue to be made in the interest of reducing acrylamide levels in food locally.

  13. Dietary exposure of secondary school students in Hong Kong to benzoic acid in prepackaged non-alcoholic beverages.

    PubMed

    Ma, Ka Ming; Chan, Cheok Man; Chung, Stephen Wai Cheung; Ho, Yuk Yin; Xiao, Ying

    2009-01-01

    This study evaluated the dietary exposure of secondary school students in Hong Kong to benzoic acid from pre-packaged non-alcoholic beverages. Exposure was estimated using local food consumption data of secondary school students obtained by a semi-quantitative food frequency questionnaire in 2000 and the benzoic acid level detected in pre-packaged beverages, including soft drink (both diet/light and regular types), fruit juice, soy milk, Chinese tea and coffee/tea) available locally in late 2006. The estimated dietary exposure to benzoic acid from pre-packaged beverages of average and high consumers (95(th) percentile) was 0.31 and 0.97 mg kg(-1) bw day(-1), respectively. These exposures accounted for 6.1 and 19.3% of the acceptable daily intake (ADI: 0-5 mg kg(-1) bw) of benzoic acid for average and high consumers, respectively. As in other countries, soft drinks contributed most to dietary exposure to benzoic acid from pre-packaged beverages in Hong Kong.

  14. AGE-RELATED TOXICITY PATHWAY ANALYSIS IN BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental exposures is poorly understood. To investigate-the contribution of different life stages on response to toxicants, we examined the effects of an acute exposure to the volatile organic compound, toluene (0.0 or 1.0 g/kg), i...

  15. ASSESSING THE IMPORTANCE OF THE BEHAVIORAL EFFECT OF ACUTE EXPOSURE TO TOLUENE IN HUMANS.

    EPA Science Inventory

    There is increasing interest in being able to evaluate potential benefit-cost relationships of controlling exposure to toxic substances. Behavioral effects of acute toluene exposure could be subjected to benefit-cost analysis if it's effects were quantitatively compared to tho...

  16. ACUTE EXPOSURE TO MOLINATE ALTERS NEUROENDOCRINE CONTROL OF OVULATION IN THE RAT

    EPA Science Inventory

    Molinate, a thiocarbamate herbicide, has been shown previously to impair reproductive capability in the male rat. In a two-generation study, molinate exposure to female rats resulted in altered pregnancy outcome. However, published data is lacking on the effects of acute exposure...

  17. USE OF LETHALITY DATA DURING CATEGORICAL REGRESSION MODELING OF ACUTE REFERENCE EXPOSURES

    EPA Science Inventory

    Categorical regression is being considered by the U.S. EPA as an additional tool for derivation of acute reference exposures (AREs) to be used for human health risk assessment for exposure to inhaled chemicals. Categorical regression is used to calculate probability-response fun...

  18. AGE-RELATED TOXICITY PATHWAY ANALYSIS IN BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental exposures is poorly understood. To investigate-the contribution of different life stages on response to toxicants, we examined the effects of an acute exposure to the volatile organic compound, toluene (0.0 or 1.0 g/kg), i...

  19. ACUTE EXPOSURE TO MOLINATE ALTERS NEUROENDOCRINE CONTROL OF OVULATION IN THE RAT

    EPA Science Inventory

    Molinate, a thiocarbamate herbicide, has been shown previously to impair reproductive capability in the male rat. In a two-generation study, molinate exposure to female rats resulted in altered pregnancy outcome. However, published data is lacking on the effects of acute exposure...

  20. ASSESSING THE IMPORTANCE OF THE BEHAVIORAL EFFECT OF ACUTE EXPOSURE TO TOLUENE IN HUMANS.

    EPA Science Inventory

    There is increasing interest in being able to evaluate potential benefit-cost relationships of controlling exposure to toxic substances. Behavioral effects of acute toluene exposure could be subjected to benefit-cost analysis if it's effects were quantitatively compared to tho...

  1. Oxidative stress and immunologic responses following a dietary exposure to PAHs in Mya arenaria

    PubMed Central

    Pichaud, Nicolas; Pellerin, Jocelyne; Fournier, Michel; Gauthier-Clerc, Sophie; Rioux, Pascal; Pelletier, Émilien

    2008-01-01

    Background The aim of this research was to investigate oxidative stress and immune responses following a dietary polycyclic aromatic hydrocarbon (PAH) exposure in a marine bioindicator organism, the soft shell clam, Mya arenaria. Immune parameters in hemolymph (haemocyte number, efficiency of phagocytosis and haemocyte activity) and assessment of oxidative stress using catalase (CAT) activity and levels of malondialdehyde (MDA) performed on the digestive gland were estimated as biomarkers in clams fed in mesocosm with PAH contaminated phytoplankton. MDA levels and CAT activities were also measured in situ in organisms sampled in a control site (Metis Beach, Québec, Canada) as well as organisms sampled in a site receiving domestic effluents (Pointe-au-Père, Québec, Canada), to assess effects of abiotic variables related to seasonal variations and mixed contamination on the selected parameters. Results Results on immune parameters suggest that the PAHs may interfere with the maturation and/or differentiation processes of haemocytes. MDA results showed that lipid peroxidation did not occur following the exposure. The levels of CAT activity corresponded to weak antioxidant activity (no significant differences). Recovery was noted for all the immune endpoints at the end of the experiment. Conclusion Results suggest that immune parameters are early biomarkers that can efficiently detect a physiological change during a short term exposure to low concentrations of PAHs. The in situ survey (in the natural environment) suggested that clams from the Pointe-au-Père site did not show any oxidative stress as well as the clams contaminated in mesocosm, probably due to the low concentrations of PAHs used for this study. MDA levels increased however in organisms from Metis Beach, a response probably related to domestic effluents or parasitism. PMID:19055737

  2. Scopolamine in racing horses: trace identifications associated with dietary or environmental exposure.

    PubMed

    Brewer, Kimberly; Dirikolu, Levent; Hughes, Charlie G; Tobin, Thomas

    2014-03-01

    Scopolamine (L-hyoscine) identifications, often in small-number clusters, have been reported worldwide in performance horses over the last 30 years. Scopolamine is an Association of Racing Commissioners International (ARCI) class 3, penalty class B, substance with potential to affect performance. As such, scopolamine identification(s) in race or performance horses can result in significant penalties for the connections of the horse(s). Reviewed here is the worldwide distribution of scopolamine containing plants (primarily Datura spp.), with estimates of their potential toxicity to horses through dietary and/or environmental exposure. Also reviewed are the basic pharmacology of scopolamine and its precursor, urinary concentrations following feedstuff exposure, and the probable pharmacological/forensic significance of such findings. Based on an overview of the world literature on scopolamine, the expected characteristics of inadvertent environmental exposure are also presented with a view to making clear the potential of scopolamine identifications, with or without atropine, as a direct and expected outcome of both the worldwide distribution of scopolamine-containing plants and the sensitivity of modern equine drug testing. It is of particular interest that only 2/30 reported post-event equine identifications of scopolamine have been associated with atropine, suggesting that failure to identify atropine is not a biomarker of pharmaceutical administration of scopolamine. Available quantitative information associated with scopolamine identifications is consistent with the 75 ng/mL regulatory threshold for scopolamine currently used in Louisiana racing in the USA and the 30 ng/mL reporting threshold in effect in European racing.

  3. Dietary exposure to polychlorinated biphenyls and risk of myocardial infarction in men - A population-based prospective cohort study.

    PubMed

    Bergkvist, Charlotte; Berglund, Marika; Glynn, Anders; Julin, Bettina; Wolk, Alicja; Åkesson, Agneta

    2016-03-01

    Major food contaminants such as polychlorinated biphenyls (PCBs) are proposed to play a role in the etiology of cardiovascular disease (CVD), but to date the impact of PCBs on cardiovascular health need to be explored. We assessed the association between validated food frequency questionnaire-based estimates of dietary PCB exposure and risk of myocardial infarction, ascertained through register-linkage, among 36,759 men from the population-based Swedish Cohort of Men, free of cardiovascular disease, diabetes and cancer at baseline (1997). Relative risks were adjusted for known cardiovascular risk factors, long-chain omega-3 fatty acids (eicosapentaenoic and docosahexaenoic acids) and methyl mercury exposure. During 12years of follow-up (433,243 person-years), we ascertained 3005 incident cases of myocardial infarction (654 fatal). Compared with the lowest quintile of dietary PCB exposure (median 113ng/day), men in the highest quintile (median 436ng/day) had multivariable-adjusted relative risks of 1.74 (95% confidence interval [CI], 1.30-2.33; p-trend<0.001) for total and 1.97 (95% CI 1.42-2.75; p-trend<0.001) for non-fatal myocardial infarction. In mutually adjusted models, dietary PCB exposure was associated with an increased risk of myocardial infarction, while the intake of long-chain omega-3 fish fatty acids was associated with a decreased risk. We also observed an effect modification by adiposity on the association between of dietary PCB exposure and myocardial infarction, with higher risk among lean men (p value for interaction =0.03). Exposure to PCBs via diet was associated with increased risk of myocardial infarction in men. Copyright © 2015 Elsevier Ltd. All rights reserved.

  4. Phthalate Concentrations and Dietary Exposure from Food Purchased in New York State

    PubMed Central

    Lorber, Matthew; Guo, Ying; Wu, Qian; Yun, Se Hun; Kannan, Kurunthachalam; Hommel, Madeline; Imran, Nadia; Hynan, Linda S.; Cheng, Dunlei; Colacino, Justin A.; Birnbaum, Linda S.

    2013-01-01

    Background: Phthalates have been found in many personal care and industrial products, but have not previously been reported in food purchased in the United States. Phthalates are ubiquitous synthetic compounds and therefore difficult to measure in foods containing trace levels. Phthalates have been associated with endocrine disruption and developmental alteration. Objectives: Our goals were to report concentrations of phthalates in U.S. food for the first time, specifically, nine phthalates in 72 individual food samples purchased in Albany, New York, and to compare these findings with other countries and estimate dietary phthalate intake. Methods: A convenience sample of commonly consumed foods was purchased from New York supermarkets. Methods were developed to analyze these foods using gas chromatography–mass spectroscopy. Dietary intakes of phthalates were estimated as the product of the food consumption rate and concentration of phthalates in that food. Results: The range of detection frequency of individual phthalates varied from 6% for dicyclohexyl phthalate (DCHP) to 74% for di-2-ethylhexyl phthalate (DEHP). DEHP concentrations were the highest of the phthalates measured in all foods except beef [where di-n-octyl phthalate (DnOP) was the highest phthalate found], with pork having the highest estimated mean concentration of any food group (mean 300 ng/g; maximum, 1,158 ng/g). Estimated mean adult intakes ranged from 0.004 μg/kg/day for dimethyl phthalate (DMP) to 0.673 μg/kg/day for DEHP. Conclusions: Phthalates are widely present in U.S. foods. While estimated intakes for individual phthalates in this study were more than an order of magnitude lower than U.S. Environmental Protection Agency reference doses, cumulative exposure to phthalates is of concern and a more representative survey of U.S. foods is indicated. PMID:23461894

  5. Dietary predictors of young children's exposure to current-use pesticides using urinary biomonitoring.

    PubMed

    Morgan, Marsha K; Jones, Paul A

    2013-12-01

    Few data exist on the association between dietary habits and urinary biomarker concentrations of pesticides in children. The objective was to examined the association between the weekly intake frequency of 65 food items and urinary biomarkers of exposure to chlorpyrifos (3,5,6-trichloro-2-pyridinol [TCP]), permethrin (3-phenoxybenzoic acid [3-PBA]), and 2,4-dichlorophenoxyacetic acid [2,4-D] in 135 preschool-aged children. TCP and 3-PBA are nonspecific biomarkers as they are also urinary metabolites of other pesticides. TCP, 3-PBA, and 2,4-D were detected in 99%, 64%, and 92% of the urine samples, respectively. Mean urinary TCP concentrations were statistically significantly higher in children consuming fresh apples (9.40±15.5 ng/mL versus 5.76±3.57 ng/mL, p=0.040) and fruit juices (8.41±11.5 ng/mL versus 4.11±2.77 ng/mL, p=0.020) ≥3 times a week compared to <3 times a week. For 3-PBA, mean urinary metabolite concentrations were statistically significantly greater in children consuming chicken/turkey meats (0.79±0.81 versus 0.41±0.39, p=0.013) ≥3 times a week compared to <3 times a week. No association occurred between the consumption of any food item and children's mean urinary 2,4-D concentrations by intake group. In conclusion, frequent consumption of fresh apples and fruit juices or chicken/turkey meats were significant dietary predictors of urinary levels of TCP or 3-PBA, respectively. Published by Elsevier Ltd.

  6. Macronutrient composition determines accumulation of persistent organic pollutants from dietary exposure in adipose tissue of mice.

    PubMed

    Myrmel, Lene Secher; Fjære, Even; Midtbø, Lisa Kolden; Bernhard, Annette; Petersen, Rasmus Koefoed; Sonne, Si Brask; Mortensen, Alicja; Hao, Qin; Brattelid, Trond; Liaset, Bjørn; Kristiansen, Karsten; Madsen, Lise

    2016-01-01

    Accumulation of persistent organic pollutants (POPs) has been linked to adipose tissue expansion. As different nutrients modulate adipose tissue development, we investigated the influence of dietary composition on POP accumulation, obesity development and related disorders. Lifespan was determined in mice fed fish-oil-based high fat diets during a long-term feeding trial and accumulation of POPs was measured after 3, 6 and 18months of feeding. Further, we performed dose-response experiments using four abundant POPs found in marine sources, PCB-153, PCB-138, PCB-118 and pp'-DDE as single congeners or as mixtures in combination with different diets: one low fat diet and two high fat diets with different protein:sucrose ratios. We measured accumulation of POPs in adipose tissue and liver and determined obesity development, glucose tolerance, insulin sensitivity and hepatic expression of genes involved in metabolism of xenobiotics. Compared with mice fed diets with a low protein:sucrose ratio, mice fed diets with a high protein:sucrose ratio had significantly lower total burden of POPs in adipose tissue, were protected from obesity development and exhibited enhanced hepatic expression of genes involved in metabolism and elimination of xenobiotics. Exposure to POPs, either as single compounds or mixtures, had no effect on obesity development, glucose tolerance or insulin sensitivity. In conclusion, this study demonstrates that the dietary composition of macronutrients profoundly modulates POP accumulation in adipose tissues adding an additional parameter to be included in future studies. Our results indicate that alterations in macronutrient composition might be an additional route for reducing total body burden of POPs. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. Effects of acute electromagnetic fields exposure on the interhemispheric homotopic functional connectivity during resting state.

    PubMed

    Lv, Bin; Shao, Qing; Chen, Zhiye; Ma, Lin; Wu, Tongning

    2015-08-01

    In this paper, we aimed to investigate the possible effects of acute radiofrequency electromagnetic fields (EMF) on the interhemispheric homotopic functional connectivity with resting state functional magnetic resonance imaging (fMRI) technique. We designed a controllable LTE-related EMF exposure environment at 2.573 GHz and performed the 30 min real/sham exposure experiments on human brain under the safety limits. The resting state fMRI signals were collected before and after EMF exposure. Then voxel-mirrored homotopic connectivity method was utilized to evaluate the acute effects of LTE EMF exposure on the homotopic functional connectivity between two human hemispheres. Based on our previous research, we further demonstrated that the 30 min short-term LTE EMF exposure would modulate the interhemispheric homotopic functional connectivity in resting state around the medial frontal gyrus and the paracentral lobule during the real exposure.

  8. Dietary exposure to polychlorinated biphenyls and risk of myocardial infarction - a population-based prospective cohort study.

    PubMed

    Bergkvist, Charlotte; Berglund, Marika; Glynn, Anders; Wolk, Alicja; Åkesson, Agneta

    2015-03-15

    Fish consumption may promote cardiovascular health. The role of major food contaminants, such as polychlorinated biphenyls (PCBs) common in fatty fish, is unclear. We assessed the association between dietary PCB exposure and risk of myocardial infarction taking into account the intake of long-chain omega-3 fish fatty acids. In the prospective population-based Swedish Mammography Cohort, 33,446 middle-aged and elderly women, free from cardiovascular disease, cancer and diabetes at baseline (1997) were followed-up for 12 years. Validated estimates of dietary PCB exposure and intake of fish fatty acids (eicosapentaenoic acid and docosahexaenoic acid; EPA-DHA) were obtained via a food frequency questionnaire at baseline. During follow-up 1386 incident cases of myocardial infarction were ascertained through register-linkage. Women in the highest quartile of dietary PCB exposure (median 286 ng/day) had a multivariable-adjusted RR of myocardial infarction of 1.21 (95% confidence interval [CI], 1.01-1.45) compared to the lowest quartile (median 101 ng/day) before, and 1.58 (95% CI, 1.10-2.25) after adjusting for EPA-DHA. Stratification by low and high EPA-DHA intake, resulted in RRs 2.20 (95% CI, 1.18-4.12) and 1.73 (95% CI, 0.81-3.69), respectively comparing highest PCB tertile with lowest. The intake of dietary EPA-DHA was inversely associated with risk of myocardial infarction after but not before adjusting for dietary PCB. Exposure to PCBs was associated with increased risk of myocardial infarction, while some beneficial effect was associated with increasing EPA and DHA intake. To increase the net benefits of fish consumption, PCB contamination should be reduced to a minimum. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. Acute Exposure Guideline Levels (AEGLs) for Time Varying Toxic Plumes

    DTIC Science & Technology

    2014-09-12

    chemicals for a general population. Inhalation exposures in the real world, however, vary strongly in space and time and thus do not correspond to the...12-09-2014 Memorandum Report Toxic airborne contaminants Health effects prediction Space and time varying exposures Extension of EPA AEGLs 64-4464...few fixed-duration exposures to a few constant-density conditions are tabulated. The issue of how to treat real toxic plumes, whose agent density

  10. Safety of a Bioactive Polyphenol Dietary Supplement in Pediatric Subjects with Acute Diarrhoea

    PubMed Central

    Sarker, Shafiqul A.; Sultana, Shamima; Pietroni, Mark; Dover, Arthur

    2015-01-01

    The hematological and clinical chemistry profile for children aged 6 months to 5 years with acute diarrhoea was measured in a double blind clinical trial. Subjects were randomized to the study group (N = 44) given a bioactive polyphenol dietary supplement in oral rehydration solution (ORS) or to the control group (N = 41) given distilled water as a placebo in ORS twice daily for up to 4 days. All subjects received 10 mg zinc daily for the 4 days in the study. Venous blood was collected for complete blood count, electrolytes, liver function, and creatinine upon enrollment (baseline) and at the end of 4 days (end of study); mean values were compared by 95% confidence intervals. Overall, blood factors measured either remained the same over the 4 days or increased or decreased at the same levels between the two groups during the study period. All values were within accepted ranges for paediatric subjects except serum AST (SGOT), where the mean value of the study group approached the upper bound of the range on day 4 but was comparable to the value of the control group. Consumption of this supplement twice daily for 4 days is safe for children and infants. PMID:26435718

  11. NRF2 and the Phase II Response in Acute Stress Resistance Induced by Dietary Restriction

    PubMed Central

    Hine, Christopher M.; Mitchell, James R.

    2013-01-01

    Dietary restriction (DR) as a means to increase longevity is well-established in a number of model organisms from yeast to primates. DR also improves metabolic fitness and increases resistance to acute oxidative, carcinogenic and toxicological stressors - benefits with more immediate potential for clinical translation than increased lifespan. While the detailed mechanism of DR action remains unclear, a conceptual framework involving an adaptive, or hormetic response to the stress of nutrient/energy deprivation has been proposed. A key prediction of the hormesis hypothesis of DR is that beneficial adaptations occur in response to an increase in reactive oxygen/nitrogen species (ROS). These ROS may be derived either from increased mitochondrial respiration or increased xenobiotic metabolism in the case of some DR mimetics. This review will focus on the potential role of the redox-sensing transcription factor NF-E2-related factor 2 (NRF2) and its control of the evolutionarily conserved antioxidant/redox cycling and detoxification systems, collectively known as the Phase II response, in the adaptive response to DR. PMID:23505614

  12. Time course of airway remodelling after an acute chlorine gas exposure in mice

    PubMed Central

    Tuck, Stephanie A; Ramos-Barbón, David; Campbell, Holly; McGovern, Toby; Karmouty-Quintana, Harry; Martin, James G

    2008-01-01

    Accidental chlorine (Cl2) gas inhalation is a common cause of acute airway injury. However, little is known about the kinetics of airway injury and repair after Cl2 exposure. We investigated the time course of airway epithelial damage and repair in mice after a single exposure to a high concentration of Cl2 gas. Mice were exposed to 800 ppm Cl2 gas for 5 minutes and studied from 12 hrs to 10 days post-exposure. The acute injury phase after Cl2 exposure (≤ 24 hrs post-exposure) was characterized by airway epithelial cell apoptosis (increased TUNEL staining) and sloughing, elevated protein in bronchoalveolar lavage fluid, and a modest increase in airway responses to methacholine. The repair phase after Cl2 exposure was characterized by increased airway epithelial cell proliferation, measured by immunoreactive proliferating cell nuclear antigen (PCNA), with maximal proliferation occurring 5 days after Cl2 exposure. At 10 days after Cl2 exposure the airway smooth muscle mass was increased relative to controls, suggestive of airway smooth muscle hyperplasia and there was evidence of airway fibrosis. No increase in goblet cells occurred at any time point. We conclude that a single exposure of mice to Cl2 gas causes acute changes in lung function, including pulmonary responsiveness to methacholine challenge, associated with airway damage, followed by subsequent repair and airway remodelling. PMID:18702818

  13. Dietary selenium protects against selected signs of aging and methylmercury exposure.

    PubMed

    Heath, John C; Banna, Kelly M; Reed, Miranda N; Pesek, Erin F; Cole, Nathan; Li, Jun; Newland, M Christopher

    2010-03-01

    Acute or short-term exposure to high doses of methylmercury (MeHg) causes a well-characterized syndrome that includes sensory and motor deficits. The environmental threat from MeHg, however, comes from chronic, low-level exposure, the consequences of which are poorly understood. Selenium (Se), an essential nutrient, both increases deposition of mercury (Hg) in neurons and mitigates some of MeHg's neurotoxicity in the short term, but it is unclear whether this deposition produces long-term adverse consequences. To investigate these issues, adult Long-Evans rats were fed a diet containing 0.06 or 0.6 ppm of Se as sodium selenite. After 100 days on these diets, the subjects began consuming 0.0, 0.5, 5.0, or 15 ppm of Hg as methylmercuric chloride in their drinking water for 16 months. Somatosensory sensitivity, grip strength, hindlimb cross (clasping reflex), flexion, and voluntary wheel-running in overnight sessions were among the measures examined. MeHg caused a dose- and time-dependent impairment in all measures. No effects appeared in rats consuming 0 or 0.5 ppm of Hg. Somatosensory function, grip strength, and flexion were among the earliest signs of exposure. Selenium significantly delayed or blunted MeHg's effects. Selenium also increased running in unexposed animals as they aged, a novel finding that may have important clinical implications. Nerve pathology studies revealed axonal atrophy or mild degeneration in peripheral nerve fibers, which is consistent with abnormal sensorimotor function in chronic MeHg neurotoxicity. Lidocaine challenge reproduced the somatosensory deficits but not hindlimb cross or flexion. Together, these results quantify the neurotoxicity of long-term MeHg exposure, support the safety and efficacy of Se in ameliorating MeHg's neurotoxicity, and demonstrate the potential benefits of Se during aging.

  14. Effect of acute and chronic excesses of dietary nitrogen on blood neutrophil functions in cattle.

    PubMed

    Raboisson, D; Caubet, C; Tasca, C; De Marchi, L; Ferraton, J M; Gannac, S; Millet, A; Enjalbert, F; Schelcher, F; Foucras, G

    2014-12-01

    Excess dietary nitrogen (EDN) is commonly expected in dairy herds, but no data are available regarding its consequences on cattle immunity. In this study neutrophil functions were assessed during EDN in steers. In experiment 1, 4 one-month periods, 4 diets [16% crude protein (CP; DM basis), 20% CP based on soybean meal, 20% CP based on urea, and 24% CP based on urea and soybean meal], and 4 steers were included in a crossover design to determine the effects of a chronic excess. In experiment 2, the repercussions of an acute excess were assessed with 2 periods of 10 d, the same 4 steers, and 2 diets containing 14 and 20% CP. Sampling was done during the fourth week of each period in experiment 1, and on d 0, 1, 2, 3, 7, and 9 of each period in experiment 2. Individual blood biochemistry parameters were measured and neutrophil factors, such as counts, recovery after isolation, surface expression of CD11b and CD62L, phagocytosis, diapedesis, reactive oxygen species (ROS) production, and bacteria killing, were determined. Data were analyzed by general linear models of R, with period, diet or biochemical component, and animal as explanatory variables. The outcome variables were biochemical or immune variables. The variables diet, period, and animal were forced as fixed effects. Data collected over the entire period of experiment 2 were pooled. Several multiples linear regressions or ANOVA were performed and a Bonferroni correction was applied. In experiment 2 (acute EDN), neutrophil counts were negatively associated with nitrogen intake, conversely to CD62L expression. The observed relative neutropenia may be due to neutrophil margination because CD62L-expressing neutrophils are more likely to stick to endothelium. Interestingly, ROS production was changed by EDN: chronic EDN (experiment 1) was negatively associated with opsonized zymozan (OZ)-induced ROS production and acute EDN (experiment 2) with spontaneous ROS production. For chronic EDN, ROS production upon

  15. [Dietary exposure assessment of substances in foods : The BfR MEAL study - the first German total diet study].

    PubMed

    Sarvan, Irmela; Bürgelt, Michaela; Lindtner, Oliver; Greiner, Matthias

    2017-07-01

    The dietary exposure of a population to chemical substances is estimated based on representative consumption data and data on the occurrence of substances in foods. Consumption data in Germany for different age groups are provided by the National Nutrition Survey ll, VELS, EsKiMo and the ongoing KiESEL study. The data for the levels of substances in foods is currently obtained from the German food monitoring programme (Lebensmittel-Monitoring) and the German Food Composition Table (Bundeslebensmittelschlüssel) and is not sufficient for a comprehensive evaluation of dietary exposure in Germany. More data is needed and, in particular, the range of analysed substances should be broadened to reduce the uncertainties of the exposure assessment. A representative data basis for concentrations of substances in foods will be established with the first German total diet study, called the BfR MEAL study. The study will markedly reduce major uncertainties in the dietary exposure assessment through its wide coverage of substances in food groups, the inclusion of prepared foods, the orientation on low measurement limits as well as the analysis of substances without a reliable data basis.

  16. Immunotoxic effects of prolonged dietary exposure of male rats to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Badesha, J S; Maliji, G; Flaks, B

    1995-12-07

    The effects of low level exposure of rats to 2,3,7,8-tetrachlorodibenzo-p- dioxin (TCDD) on their immune system was investigated Dietary administration to young adult male Leeds strain rats of a total dose of 3 micrograms/kg body weight of TCDD resulted in an exposure duration-dependent reduction of in vitro lipopolysaccharide-induced production of interleukin (IL)-1 in cultures of their splenic macrophages. A 30-day exposure produced approximately 30% suppression and 180-day exposure produced approximately 52% suppression. This reduction did not negatively influence lipopolysaccharide- induced proliferation of B cells, instead an enhancement of B cell proliferation was observed after 30 days exposure. A 180 day exposure significantly suppressed the generation of IL-2 by either concanavalin A or phorbol myristate acetate/calcium ionophore stimulation, and reduced the lectin-induced proliferation of splenic T cells. The 30-day TCDD exposure showed no such immunotoxicity. TCDD at both exposure durations suppressed the expression of the alpha chain of the IL-2 receptor in concanavalin A-activated T cells, without affecting the CD4+/CD8+ ratio. The results suggest that exposure to a low dietary dose of TCDD suppresses the functions of several T cell subsets, some of the immunotoxic effects being produced early, while others require a longer exposure also down-regulates the IL-1 production function of macrophages. A common mechanism of TCDD immunotoxicity may be on the multifunctional signal transduction pathways downstream to the activation of protein kinase C and Ca2+ flux.

  17. Dietary exposure to brominated flame retardants and abnormal Pap test results.

    PubMed

    Jamieson, Denise J; Terrell, Metrecia L; Aguocha, Nnenna N; Small, Chanley M; Cameron, Lorraine L; Marcus, Michele

    2011-09-01

    This study examined a possible association of dietary exposure to polybrominated biphenyls (PBBs), a brominated flame retardant, and self-reported abnormal Pap test results and cervical dysplasia as a precursor to cervical cancer. Women in Michigan who ingested contaminated poultry, beef, and dairy products in the early 1970s were enrolled in a population-based cohort study in Michigan. Serum PBB and serum polychlorinated biphenyl (PCB) concentrations were measured. Reproductive history and health information, including Pap test results, were self-reported by participants. Of the women, 23% (223 of 956) reported an abnormal Pap test. In unadjusted analyses, self-reporting an abnormal Pap test was associated with younger age, current smoking (hazard ratio [HR] 1.61, 95% confidence interval [CI] 1.19-2.17), and longer duration of lifetime use of oral contraceptives (≥10 years; HR 1.92, 95% CI 1.21-3.06). When adjusting for PCB exposure, age at the interview, and smoking history, there was a slightly elevated risk of self-reporting an abnormal Pap test among the highly exposed women compared to women with nondetectable PBB concentrations (PBB≥13 μg/L, HR 1.23, 95% CI 0.74-2.06); however, the CI was imprecise. When breastfeeding duration after the initial PBB measurement was taken into account, there was a reduced risk of self-reporting an abnormal Pap test among the highly exposed women who breastfed for ≥12 months (HR 0.41, 95% CI 0.06-3.03; referent group: women with nondetectable PBB concentrations who did not breastfeed). It remains important to evaluate the potential reproductive health consequences of this class of chemicals as well as other potential predictors of abnormal Pap tests.

  18. [Effect of acute exposure to high altitude on pharmacokinetics of propranolol and metoprolol in rats].

    PubMed

    Zhang, Juanhong; Wang, Rong; Xie, Hua; Yin, Qiang; Jia, Zhengping; Li, Wenbin

    2014-11-01

    To study the pharmacokinetics of propranolol and metoprolol in rats after acute exposure to high altitude. Wistar rats were randomly assigned into 4 groups for treatment with intragastric administration of propranolol or metoprolol after acute exposure to high altitude (4010 m) or normal altitude (50 m). Venous blood samples were collected from the rats at different time points after drug administration to determine the drug concentrations in the plasma and plasma ultrafiltrate using liquid chromatography-mass spectrometry (LC-MS/MS). The protein binding rate of propranolol was significantly increased but that of metoprolol remained unchanged after acute exposure to high altitude. Compared with the rats exposed to normal altitude, the rats with acute exposure to high altitude showed significant alterations in the pharmacokinetic parameters of the drugs, shown by increased Cmax and AUC, prolonged t1/2 and MRT, and lowered Clz/F of propranolol, and by increased Tmax and prolonged t1/2 and MRT of metoprolol without obvious changes of the parameters of the compartmental model. Significant changes in the pharmacokinetics of propranolol and metoprolol occur in rats after acute exposure to high altitude possibly in relation to, apart from the changes in plasma protein binding ratio and blood gas, alterations in metabolic enzyme activities, increased blood viscosity, and species and general conditions of the animals.

  19. Response of α-glucosidase in gypsy moth larvae to acute and chronic dietary cadmium.

    PubMed

    Vlahović, Milena S; Mataruga, Vesna D Perić; Lazarević, Jelica M; Mrdaković, Marija M; Matić, Dragana R; Todorović, Dajana D; Ilijin, Larisa A

    2015-01-01

    We investigated the effects of acute and chronic treatments with cadmium at 10 μg Cd/g dry food and 30 μg Cd/g dry food on α-glucosidase activity of the 4th instar larvae of Lymantria dispar (Lepidoptera: Lymantriidae) as well as subsequent recovery. Enzyme inhibition was recorded during acute exposure to 30 μg Cd/g dry food and during chronic treatment at the lower metal concentration. After three days recovery from 10 μg Cd/g dry food, the α-glucosidase activity returned to the control level. One-way ANOVA showed that cadmium significantly influenced the activity of α-glucosidase during all treatments. The index of phenotypic plasticity was higher during chronic treatment at 10 μg Cd/g dry food than at 30 μg Cd/g as well as during the recovery. We detected four glucosidase isoforms by NATIVE PAGE. The activities and expressions of the isoforms depended on both larval genotype and cadmium treatment.

  20. Effects of acute exposure to nitrogen dioxide on primary antibody response

    SciTech Connect

    Hidekazu, F.; Fujio, S.

    1981-01-01

    The effects of acute exposure to nitrogen dioxide on primary humoral antibody response to sheep red blood cells in mice were studied. Mice were exposed to 5 ppm, 20 ppm, and 40 ppm nitrogen dioxide for 12 hr. An exposure of 20 ppm or 40 ppm resulted in a significant suppression of antibody responses, but 5 ppm did not affect antibody response. This immunosuppression resulting from nitrogen dioxide exposure was more apparent in males than females. Exposures to 20 ppm nitrogen dioxide for various time intervals revealed that the strongest suppression effect was observed in the group exposed 2 days after antigen injection. A decreased total cell number in the spleen, and more strikingly, in the thymus, was also caused by acute exposure to nitrogen dioxide.

  1. Effects of acute exposure to nitrogen dioxide on primary antibody response

    SciTech Connect

    Hidekazu, F.; Fujio, S.

    1981-05-01

    The effects of acute exposure to nitrogen dioxide on primary humoral antibody response to sheep red blood cells in mice were studied. Mice were exposed to 5 ppM, 20 ppM, and 40 ppM nitrogen dioxide for 12 h. An exposure of 20 ppM or 40 ppM resulted in a significant suppression of antibody responses, but 5 ppM did not affect antibody response. This immunosuppression resulting from nitrogen dioxide exposure was more apparent in males than females. Exposures to 20 ppM nitrogen dioxide for various time intervals revealed that the strongest suppression effect was observed in the group exposed 2 days after antigen injection. A decreased total cell number in the spleen, and more strikingly, in the thymus, was also caused by acute exposure to nitrogen dioxide.

  2. Communicating Results of a Dietary Exposure Study Following Consumption of Traditionally Smoked Salmon

    PubMed Central

    Frey, Greta; Kile, Molly L.; Harper, Barbara; Harris, Stuart; Motorykin, Oleksii; Simonich, Staci L. Massey; Harding, Anna K.

    2016-01-01

    Abstract One expectation of community-based participatory research (CBPR) is participant access to study results. However, reporting experimental data produced by studies involving biological measurements in the absence of clinical relevance can be challenging to scientists and participants. We applied best practices in data sharing to report the results of a study designed to explore polycyclic aromatic hydrocarbons absorption, metabolism, and excretion following consumption of traditionally smoked salmon by members of the Confederated Tribes of the Umatilla Indian Reservation (CTUIR). A dietary exposure study was developed, in which nine Tribal members consumed 50 g of traditionally smoked salmon and provided repeated urine samples over 24 hours. During recruitment, participants requested access to their data following analysis. Disclosing data is an important element of CBPR and must be treated with the same rigor as that given to the data analysis. The field of data disclosure is relatively new, but when handled correctly can improve education within the community, reduce distrust, and enhance environmental health literacy. Using the results from this study, we suggest mechanisms for sharing data with a Tribal community. PMID:28804531

  3. Toxicological effects of short-term dietary acrylamide exposure in male F344 rats.

    PubMed

    Raju, Jayadev; Roberts, Jennifer; Taylor, Marnie; Patry, Dominique; Chomyshyn, Emily; Caldwell, Don; Cooke, Gerard; Mehta, Rekha

    2015-01-01

    We recently reported that acrylamide, a known rodent and probable human carcinogen, does not increase the risk of azoxymethane (AOM)-induced rat colon precancerous lesions when administered through the diet. Here, we present toxicological data from non-AOM-injected rats. Briefly, male F344 rats were randomized into four dietary groups and received experimental diets based on AIN-93G formulation and containing acrylamide at 0 (control), 5, 10 or 50mg/kg diet (wt/wt) ad libitum for 10 weeks, after which they were killed and their blood collected for hematological and biochemical markers. Acrylamide at the higher doses (10 and 50mg/kg diet) significantly lowered (p<0.05) serum total high density lipoprotein and total testosterone and increased serum lipase in comparison to the control. Blood hematocrit values and lymphocyte counts were significantly lower (p<0.05) in the high dose acrylamide (50mg/kg diet) group compared to control, with a concomitant decrease in hemoglobin level, mean corpuscular volume and mean corpuscular hemoglobin. These results provide additional hazard characterization data and strengthen the notion that at high doses, acrylamide may involve systemic toxicity potentiating tumorigenesis in experimental animals. Further studies are required to understand the health effects of food-borne acrylamide, especially at the lower exposures typified by human diets. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

  4. Toxicity of 2,4,4{prime}-trichlorobiphenyl in rats following 90-day dietary exposure

    SciTech Connect

    Chu, I.; Villeneuve, D.C.; Yagminas, A.; Lecavalier, P.; Poon, R.

    1996-10-25

    The toxicity of 2,4,4{prime}-trichlorobiphenyl (PCB 28) was investigated in rats after a 90-d dietary exposure. Groups of 10 male and 10 female weanling Sprague-Dawley rats were administered PCB 28 in the diet at 0, 0.05, 0.50, 5.0, or 50.0 ppm for 13 wk. Growth rate and food consumption were not affected by treatment, and no clinical signs of toxicity were observed. Mottled liver was noted in both control and PCB-treated males, but was found with increased incidence in the highest treatment group. Increased urinary ascorbic acid and hepatic microsomal ethoxyresorufin O-deethylase activity were observed in the 50.0 ppm group of both sexes. The vitamin A content in liver, lung, and kidney was not significantly affected by treatment. Analysis of brain biogenic amines showed a decreased dopamine concentration in the substantial nigra region of female rats receiving 0.5 ppm PCB 28 and higher doses. Female rats appeared top be more sensitive than males to the neurochemical effects of PCB 28. Dose-dependent histologic changes were observed in the thyroid and liver, with biologically significant changes occurring at 5.0 ppm and above. Based on these data, the no-observable-adverse-effect level (NOAEL) for this PCB congener was considered to be 0.5 ppm in diet or 36 {mu}g/kg body weight/d. 26 refs., 6 figs., 3 tabs.

  5. Between exposure, access and use: Reconsidering foodscape influences on dietary behaviours.

    PubMed

    Clary, Christelle; Matthews, Stephen Augustus; Kestens, Yan

    2017-03-01

    Good accessibility to both healthy and unhealthy food outlets is a greater reality than food deserts. Yet, there is a lack of conceptual insights on the contextual factors that push individuals to opt for healthy or unhealthy food outlets when both options are accessible. Our comprehension of foodscape influences on dietary behaviours would benefit from a better understanding of the decision-making process for food outlet choices. In this paper, we build on the fundamental position that outlet choices are conditioned by how much outlets' attributes accommodate individuals' constraints and preferences. We further argue that food outlets continuously experienced within individuals' daily-path help people re-evaluate food acquisition possibilities, push them to form intentions, and shape their preferences for the choices they will subsequently make. Doing so, we suggest differentiating access, defined as the potential for the foodscape to be used at the time when individuals decide to do so, from exposure, which acts as a constant catalyst for knowledge, intention, preferences and routine tendency. We conclude with implications for future research, and discuss consequences for public policy.

  6. Resistance of developing honeybee larvae during chronic exposure to dietary nicotine.

    PubMed

    Human, H; Archer, C R; du Rand, E E; Pirk, C W W; Nicolson, S W

    2014-10-01

    The effects of pesticides on honeybee larvae are less understood than for adult bees, even though larvae are chronically exposed to pesticide residues that accumulate in comb and food stores in the hive. We investigated how exposure to a plant alkaloid, nicotine, affects survival, growth and body composition of honeybee larvae. Larvae of Apis mellifera scutellata were reared in vitro and fed throughout development on standard diets with nicotine included at concentrations from 0 to 1000μg/100g diet. Overall mortality across all nicotine treatments was low, averaging 9.8% at the prepupal stage and 18.1% at the white-eyed pupal stage, but survival was significantly reduced by nicotine. The mass of prepupae and white-eyed pupae was not affected by nicotine. In terms of body composition, nicotine affected water content but did not influence either protein or lipid stores of white-eyed pupae. We attribute the absence of consistent negative effects of dietary nicotine to detoxification mechanisms in developing honeybees, which enable them to resist both natural and synthetic xenobiotics.

  7. Exposure to media predicts use of dietary supplements and anabolic-androgenic steroids among Flemish adolescent boys.

    PubMed

    Frison, Eline; Vandenbosch, Laura; Eggermont, Steven

    2013-10-01

    This study examined whether different types of media affect the use of dietary proteins and amino acid supplements, and intent to use anabolic-androgenic steroids. A random sample of 618 boys aged 11-18 years from eight schools in the Flemish part of Belgium completed standardized questionnaires as part of the Media and Adolescent Health Study. The survey measured exposure to sports media, appearance-focused media, fitness media, use of dietary supplements, and intent to use anabolic-androgenic steroids. Data were analyzed using logistic regressions and are presented as adjusted odds ratios (OR) and 95 % confidence intervals (CI); 8.6 % indicated to have used dietary proteins, 3.9 % indicated to have used amino acid supplements, and 11.8 % would consider using anabolic-androgenic steroids. After adjusting for fitness activity, exposure to fitness media was associated with the use of dietary proteins (OR = 7.24, CI = 2.25-23.28) and amino acid supplements (5.16, 1.21-21.92; 44.30, 8.25-238). Intent to use anabolic-androgenic steroids was associated with exposure to fitness media (2.38, 1.08-5.26; 8.07, 2.55-25.53) and appearance-focused media (6.02, 1.40-25.82; 8.94, 1.78-44.98). Sports media did not correlate with the use of dietary supplements and intent to use anabolic-androgenic steroids. Specific types of media are strong predictors of the use of supplements in adolescent boys. This provides an opportunity for intervention and prevention through the selection of fitness media as a communication channel. Health practitioners should also be aware that the contemporary body culture exerts pressure not only on girls but also on boys.

  8. [Probabilistic assessment of dietary exposure to both deoxynivalenol and zearalenone from cereal-based products in Chinese populations].

    PubMed

    Wang, Wei; Zhu, Jianghui; Shao, Bing; Li, Fengqin

    2015-03-01

    To elucidate the dietary exposure to deoxynivalenol (DON) and zearalenone (ZEN) from cereal-based products in Chinese populations using the probabilistic assessment approach. A total of 292 wheat flours and 347 corn-based products were collected from sampling sites of 107 supermarkets or farmers markets, which were randomly selected from 44 cities of 13 provinces in 2009 by the stratified cluster random sampling method. Then, DON and ZEN contamination levels in these samples above analyzed by UPLC-MS/MS in combination with the food consumption data of 68 959 respondents, who were divided into group 1 aged 3 to 13 years old, and group 2 aged 14 and over 14 years old (≥14 years old), obtained by China National Nutrition and Health Survey in 2002 were investigated. A probabilistic assessment model using Monte Carlo simulation was applied to derive the intake distribution of P(1)-P(99) percentile of dietary exposure to DON and ZEN. Meanwhile, all parameters related to dietary exposure to both toxins were compared with either the provisional maximum tolerable daily intake (PMTDI) of 1 µg·kg(-1)·d(-1) for DON, or the tolerable daily intake (TDI) of 0.25 µg·kg(-1)·d(-1) for ZEN in order to evaluate the risk of dietary intake of two toxins and find the minimum percentile of dietary exposure to these two toxins. The statistical differences of dietary exposure to these two toxins between two groups were achieved by t test. The detection frequencies of DON in wheat flours and corn-based products were 100% (292/292) and 97.4% (338/347), respectively. A total of 21 out of 639 samples (wheat flours: 5/292, corn-based products: 16/347) were positive for DON at the levels exceeding the Chinese regulatory limit of 1 000 µg/kg for DON. And the detection frequencies of ZEN in wheat flours and corn-based products were 53.4% (156/292) and 87.6% (304/347), respectively.54 out of 347 corn-based products and no wheat flours were positive for ZEN at the levels exceeding the

  9. Acute Neuroactive Drug Exposures alter Locomotor Activity in Larval Zebrafish

    EPA Science Inventory

    As part of the development of a rapid in vivo screen for prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae by assessing the acute effects of prototypic drugs that act on the central nervous system. Initially,...

  10. Acute Neuroactive Drug Exposures alter Locomotor Activity in Larval Zebrafish

    EPA Science Inventory

    As part of the development of a rapid in vivo screen for prioritization of toxic chemicals, we have begun to characterize the locomotor activity of zebrafish (Danio rerio) larvae by assessing the acute effects of prototypic drugs that act on the central nervous system. Initially,...

  11. A Novel Antibody-Based Biomarker for Chronic Algal Toxin Exposure and Sub-Acute Neurotoxicity

    PubMed Central

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins. PMID:22567140

  12. A novel antibody-based biomarker for chronic algal toxin exposure and sub-acute neurotoxicity

    USGS Publications Warehouse

    Lefebvre, Kathi A.; Frame, Elizabeth R.; Gulland, Frances; Hansen, John D.; Kendrick, Preston S.; Beyer, Richard P.; Bammler, Theo K.; Farin, Frederico M.; Hiolski, Emma M.; Smith, Donald R.; Marcinek, David J.

    2012-01-01

    The neurotoxic amino acid, domoic acid (DA), is naturally produced by marine phytoplankton and presents a significant threat to the health of marine mammals, seabirds and humans via transfer of the toxin through the foodweb. In humans, acute exposure causes a neurotoxic illness known as amnesic shellfish poisoning characterized by seizures, memory loss, coma and death. Regular monitoring for high DA levels in edible shellfish tissues has been effective in protecting human consumers from acute DA exposure. However, chronic low-level DA exposure remains a concern, particularly in coastal and tribal communities that subsistence harvest shellfish known to contain low levels of the toxin. Domoic acid exposure via consumption of planktivorous fish also has a profound health impact on California sea lions (Zalophus californianus) affecting hundreds of animals yearly. Due to increasing algal toxin exposure threats globally, there is a critical need for reliable diagnostic tests for assessing chronic DA exposure in humans and wildlife. Here we report the discovery of a novel DA-specific antibody response that is a signature of chronic low-level exposure identified initially in a zebrafish exposure model and confirmed in naturally exposed wild sea lions. Additionally, we found that chronic exposure in zebrafish caused increased neurologic sensitivity to DA, revealing that repetitive exposure to DA well below the threshold for acute behavioral toxicity has underlying neurotoxic consequences. The discovery that chronic exposure to low levels of a small, water-soluble single amino acid triggers a detectable antibody response is surprising and has profound implications for the development of diagnostic tests for exposure to other pervasive environmental toxins.

  13. An adaptable internal dose model for risk assessment of dietary and soil dioxin exposures in young children.

    PubMed

    Kerger, Brent D; Leung, Hon-Wing; Scott, Paul K; Paustenbach, Dennis J

    2007-11-01

    An adaptable model is presented for assessing the blood lipid concentrations of polychlorodibenzodioxins and polychlorodibenzofurans (PCDD/Fs) from dietary (breast milk, formula, milk, and other foods) and soil pathway exposures (soil ingestion and dermal contact) utilizing age-specific exposure and intake estimates for young children. The approach includes a simple one-compartment (adipose volume) toxicokinetic model that incorporates empirical data on age-dependent half-lives and bioavailability of PCDD/F congeners, child body size and intake rates, and recent data on breast milk and food dioxin levels. Users can enter site-specific soil concentration data on 2,3,7,8-chlorinated PCDD/F congeners for specific assessment of body burden changes from soil pathways in combination with background dietary exposures from birth through age 7 years. The model produces a profile of the estimated PCDD/F concentration in blood lipid (in World Health Organization 1998 dioxin toxic equivalents) versus time for a child from birth through age 7 years. The peak and time-weighted average (TWA) internal dose (defined as blood lipid dioxin toxic equivalents) for a variety of specific child exposure assumptions can then be compared to safe internal dose benchmarks for risk assessment purposes, similar to an approach taken by United States Environmental Protection Agency for assessing child lead exposures. We conclude that this adaptable toxicokinetic model can provide a more comprehensive assessment of potential health risks of PCDD/Fs to children because it integrates recent empirical findings on PCDD/F kinetics in humans and allows users to assess contributions from varied dietary and site-specific environmental exposure assumptions.

  14. Assessing the sensitivity of Atlantic salmon (Salmo salar) to dietary endosulfan exposure using tissue biochemistry and histology.

    PubMed

    Glover, Chris N; Petri, Dietrich; Tollefsen, Knut-Erik; Jørum, Nanne; Handy, Richard D; Berntssen, Marc H G

    2007-10-15

    The incorporation of plant-based ingredients, and the possible carry-over of pesticides such as endosulfan, in fish feeds may present new toxicological challenges to aquacultural species. Biological responses of Atlantic salmon (Salmo salar) to a 35-day dietary endosulfan exposure at levels ranging from 4 to 710 microgkg(-1) were assessed using tissue histology and biochemistry. Liver 7-ethoxyresorufin-O-deacetylase (EROD) activity was significantly elevated in the highest exposure group (710 microgkg(-1)) by day 35. Other hepatic indicators of stress impacts and responses (glutathione-S-transferase and glutathione peroxidase activities and hepatic alpha-tocopherol content) remained unchanged. Branchial Na(+), K(+)-ATPase activity was significantly reduced at day 14 in the highest exposure group, but returned to control levels by day 35. Conversely, intestinal Na(+), K(+)-ATPase activity was significantly inhibited at day 35, but again only at the highest exposure level. In contrast to the biochemical results, hepatic and intestinal histology revealed effects of exposure even at the lowest dose tested (4 microgkg(-1)). In the posterior intestine, pathology was characterised by vacuolation and fusion of villi, and in the most severe cases, loss of epithelial integrity in villi tips. In the liver the primary effects were glycogen depletion and lipidosis. These changes were typical of a generalised stress response. While histology endpoints may prove to be the most sensitive indicators of dietary endosulfan exposure, the organismal relevance of these structural changes must be considered in the absence of effects in other biomarkers at dietary levels less than 710 microgkg(-1).

  15. Acute low-level microwave exposure and central cholinergic activity: studies on irradiation parameters

    SciTech Connect

    Lai, H.; Horita, A.; Guy, A.W.

    1988-01-01

    Sodium-dependent high-affinity choline uptake was measured in the striatum, frontal cortex, hippocampus, and hypothalamus of rats after acute exposure (45 min) to pulsed (2 microseconds, 500 pps) or continuous-wave 2,450-MHz microwaves in cylindrical waveguides or miniature anechoic chambers. In all exposure conditions, the average whole-body specific absorption rate was at 0.6 W/kg. Decrease in choline uptake was observed in the frontal cortex after microwave exposure in all of the above irradiation conditions. Regardless of the exposure system used, hippocampal choline uptake was decreased after exposure to pulsed but not continuous-wave microwaves. Striatal choline uptake was decreased after exposure to either pulsed or continuous-wave microwaves in the miniature anechoic chamber. No significant change in hypothalamic choline uptake was observed under any of the exposure conditions studied. We conclude that depending on the parameters of the radiation, microwaves can elicit specific and generalized biological effects.

  16. Gene expression and pathologic alterations in juvenile rainbow trout due to chronic dietary TCDD exposure

    PubMed Central

    Liu, Qing; Rise, Matthew L.; Spitsbergen, Jan M.; Hori, Tiago S.; Mieritz, Mark; Geis, Steven; McGraw, Joseph E.; Goetz, Giles; Larson, Jeremy; Hutz, Reinhold J.; Carvan, Michael J.

    2013-01-01

    The goal of this project was to use functional genomic methods to identify molecular biomarkers as indicators of the impact of TCDD exposure in rainbow trout. Specifically, we investigated the effects of chronic dietary TCDD exposure on whole juvenile rainbow trout global gene expression associated with histopathological analysis. Juvenile rainbow trout were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb (ng TCDD / g food), and fish were sampled from each group at 7, 14, 28 and 42 days (d) after initiation of feeding. 100 ppb TCDD caused 100% mortality at 39 d. Fish fed with 100 ppb TCDD food had TCDD accumulation of 47.37 ppb (ng TCDD / g fish) in whole fish at 28 d. Histological analysis from TCDD-treated trout sampled from 28 d and 42 d revealed that obvious lesions were found in skin, oropharynx, liver, gas bladder, intestine, pancreas, nose and kidney. In addition, TCDD caused anemia in peripheral blood, decreases in abdominal fat, increases of remodeling of fin rays, edema in pericardium and retrobulbar hemorrhage in the 100 ppb TCDD-treated rainbow trout compared to the control group at 28 d. Dose- and time-dependent global gene expression analyses were performed using the cGRASP 16,000 (16K) cDNA microarray. TCDD-responsive whole body transcripts identified in the microarray experiments have putative functions involved in various biological processes including growth, cell proliferation, metabolic process, and immune system processes. Nine microarray-identified genes were selected for QPCR validation. CYP1A3 and CYP1A1 were common up-regulated genes and HBB1 was a common down-regulated gene among each group based on microarray data, and their QPCR validations are consistent with microarray data for the 10 and 100 ppb TCDD treatment groups after 28-d exposure (p< 0.05). In addition, in the 100 ppb group at 28d, expression of complement component C3-1 and trypsin-1 precursor have a more than 10-fold induction from the microarray experiments

  17. Gene expression and pathologic alterations in juvenile rainbow trout due to chronic dietary TCDD exposure.

    PubMed

    Liu, Qing; Rise, Matthew L; Spitsbergen, Jan M; Hori, Tiago S; Mieritz, Mark; Geis, Steven; McGraw, Joseph E; Goetz, Giles; Larson, Jeremy; Hutz, Reinhold J; Carvan, Michael J

    2013-09-15

    The goal of this project was to use functional genomic methods to identify molecular biomarkers as indicators of the impact of TCDD exposure in rainbow trout. Specifically, we investigated the effects of chronic dietary TCDD exposure on whole juvenile rainbow trout global gene expression associated with histopathological analysis. Juvenile rainbow trout were fed Biodiet starter with TCDD added at 0, 0.1, 1, 10 and 100 ppb (ngTCDD/g food), and fish were sampled from each group at 7, 14, 28 and 42 days after initiation of feeding. 100 ppb TCDD caused 100% mortality at 39 days. Fish fed with 100 ppb TCDD food had TCDD accumulation of 47.37 ppb (ngTCDD/g fish) in whole fish at 28 days. Histological analysis from TCDD-treated trout sampled from 28 and 42 days revealed that obvious lesions were found in skin, oropharynx, liver, gas bladder, intestine, pancreas, nose and kidney. In addition, TCDD caused anemia in peripheral blood, decreases in abdominal fat, increases of remodeling of fin rays, edema in pericardium and retrobulbar hemorrhage in the 100 ppb TCDD-treated rainbow trout compared to the control group at 28 days. Dose- and time-dependent global gene expression analyses were performed using the cGRASP 16,000 (16K) cDNA microarray. TCDD-responsive whole body transcripts identified in the microarray experiments have putative functions involved in various biological processes including growth, cell proliferation, metabolic process, and immune system processes. Nine microarray-identified genes were selected for QPCR validation. CYP1A3 and CYP1A1 were common up-regulated genes and HBB1 was a common down-regulated gene among each group based on microarray data, and their QPCR validations are consistent with microarray data for the 10 and 100 ppb TCDD treatment groups after 28 days exposure (p<0.05). In addition, in the 100 ppb group at 28 days, expression of complement component C3-1 and trypsin-1 precursor have a more than 10-fold induction from the microarray

  18. Consequences of acute and chronic exposure to arsenic in children.

    PubMed

    Calderon, Rebecca L; Abernathy, Charles O; Thomas, David J

    2004-07-01

    Arsenic is a toxic chemical and may cause adverse health effects in children and adults. It is known to affect the nervous, gastrointestinal, and hematological systems and cause skin and internal cancers in people exposed to levels greater than 300 ppb in their drinking water. For most people, the major exposure to arsenic comes from food (8 to 14 microg inorganic arsenic per day), but when the arsenic level in water is elevated, drinking water becomes the predominant source of exposure. Because it is very difficult to limit arsenic exposure from food, it would be wise to limit arsenic exposure from those more controllable sources. Pediatricians should ascertain the levels of arsenic in drinking water of patients with high arsenic levels, using the supplier or, in the case of private wells, a professional water-testing laboratory assay. The Safe Drinking Water Act does not cover private wells or those water systems with less than 15 hook-ups or those that serve less than 25 people. Pediatricians should instruct parents to use prepared baby formulas or prepare them using water with the arsenic removed and to curtail playing time for younger children in places that have sand containing large amounts of arsenic. Such procedures will limit arsenic exposure to a minimum.

  19. Behavioral and neurochemical changes in response to acute stressors: influence of previous chronic exposure to immobilization.

    PubMed

    Pol, O; Campmany, L; Gil, M; Armario, A

    1992-07-01

    The effect of daily (2 h) exposure to immobilization (IMO) for 15 days on the behavioral and neurochemical responses of adult male rats to acute stress caused by 2-h IMO or 2-h tail-shock was studied. The brain areas studied were frontal cortex, hippocampus, hypothalamus, midbrain, and pons plus medulla. Chronic exposure to IMO did not alter noradrenaline (NA), 3-methoxy,4-hydroxyphenyletileneglycol-SO4 (MHPG-SO4), serotonin, or 5-hydroxindoleacetic acid (5-HIAA) concentrations in any brain area as measured approximately 20 h after the last exposure to IMO. Exposure to behavioral tests did not modify neurochemical variables except NA levels in the hypothalamus of nonchronically stressed (control) rats. Both exposure to 2-h IMO or 2-h shock significantly decreased NA levels in hypothalamus and midbrain of nonchronically stressed rats. These decreases in response to the two acute stressors were not observed in chronically stressed rats. However, MHPG-SO4 levels increased to the same extent in control and chronically stressed rats after exposure to the acute stressors. Likewise, increased 5-HIAA concentrations observed in response to acute stressors were similar in control and chronically stressed rats. The inhibition of activity (areas crossed and rearing) in the holeboard caused by acute IMO was less marked in rats previously exposed to the same stressor than in control rats, but the response to shock was similar. In the forced swim test, acute IMO decreased struggling in control rats but tended to increase it in chronically stressed rats. The response to shock followed the same pattern as that to IMO, although it was slight.(ABSTRACT TRUNCATED AT 250 WORDS)

  20. Intravenous Niacin Acutely Improves the Efficiency of Dietary Fat Storage in Lean and Obese Humans

    PubMed Central

    Nelson, Robert H.; Vlazny, Danielle; Smailovic, Almira; Miles, John M.

    2012-01-01

    Spillover of fatty acids released by lipoprotein lipase hydrolysis of meal triglycerides may be a major contributor to the free fatty acid (FFA) pool. We studied lean (n = 6) and overweight and obese (n = 5) subjects during continuous feeding on two occasions: during intravenous infusion of niacin (2.8 mg/min) and saline. After establishment of steady-state chylomicronemia and suppression of adipose tissue lipolysis with a liquid meal, spillover was measured with infusions of [U-13C]oleate and [3H]triolein. Total FFA concentrations were lower during niacin infusion in both lean (50 ± 4 vs. 102 ± 7 μmol/L; P < 0.002) and obese (75 ± 6 vs. 143 ± 13 μmol/L; P < 0.01) subjects. Oleate appearance was lower during niacin infusion than during saline infusion in both lean (21 ± 2 vs. 32 ± 5 μmol/min; P = 0.07) and obese subjects (25 ± 3 vs. 46 ± 8 μmol/min; P < 0.02). Spillover was lower during niacin infusion than during saline infusion in lean (21 ± 4 vs. 29 ± 3%) and obese (21 ± 2 vs. 29 ± 5%) subjects (P < 0.03 for both). In summary, during meal absorption, niacin produces additional suppression of lipolysis and a reduction in fractional spillover compared with saline in both normal and obese subjects. Infusion of intravenous niacin provides a model for acutely improving dietary fat storage, perhaps by suppressing lipolysis in visceral adipose tissue. PMID:22923472

  1. Intravenous niacin acutely improves the efficiency of dietary fat storage in lean and obese humans.

    PubMed

    Nelson, Robert H; Vlazny, Danielle; Smailovic, Almira; Miles, John M

    2012-12-01

    Spillover of fatty acids released by lipoprotein lipase hydrolysis of meal triglycerides may be a major contributor to the free fatty acid (FFA) pool. We studied lean (n = 6) and overweight and obese (n = 5) subjects during continuous feeding on two occasions: during intravenous infusion of niacin (2.8 mg/min) and saline. After establishment of steady-state chylomicronemia and suppression of adipose tissue lipolysis with a liquid meal, spillover was measured with infusions of [U-(13)C]oleate and [(3)H]triolein. Total FFA concentrations were lower during niacin infusion in both lean (50 ± 4 vs. 102 ± 7 μmol/L; P < 0.002) and obese (75 ± 6 vs. 143 ± 13 μmol/L; P < 0.01) subjects. Oleate appearance was lower during niacin infusion than during saline infusion in both lean (21 ± 2 vs. 32 ± 5 μmol/min; P = 0.07) and obese subjects (25 ± 3 vs. 46 ± 8 μmol/min; P < 0.02). Spillover was lower during niacin infusion than during saline infusion in lean (21 ± 4 vs. 29 ± 3%) and obese (21 ± 2 vs. 29 ± 5%) subjects (P < 0.03 for both). In summary, during meal absorption, niacin produces additional suppression of lipolysis and a reduction in fractional spillover compared with saline in both normal and obese subjects. Infusion of intravenous niacin provides a model for acutely improving dietary fat storage, perhaps by suppressing lipolysis in visceral adipose tissue.

  2. Acute respiratory symptoms and evacuation-related behavior after exposure to chlorine gas leakage.

    PubMed

    Han, Sung-Woo; Choi, Won-Jun; Yi, Min-Kee; Song, Seng-Ho; Lee, Dong-Hoon; Han, Sang-Hwan

    2016-01-01

    A study was performed on the accidental chlorine gas leakage that occurred in a factory of printed circuit boards manufactured without chlorine. Health examination was performed for all 52 workers suspected of exposure to chlorine gas, and their evacuation-related behaviors were observed in addition to analyzing the factors that affected the duration of their acute respiratory symptoms. Behavioral characteristics during the incidence of the accidental chlorine gas leakage, the estimated time of exposure, and the duration of subjective acute respiratory symptoms were investigated. In addition, clinical examination, chest radiography, and dental erosion test were performed. As variables that affected the duration of respiratory symptoms, dose group, body weight, age, sex, smoking, work period, and wearing a protective gear were included and analyzed by using the Cox proportional hazard model. Of 47 workers exposed to chlorine gas, 36 (77 %) developed more than one subjective symptom. The duration of the subjective symptoms according to exposure level significantly differed, with a median of 1 day (range, 0-5 days) in the low-exposure group and 2 days (range, 0-25 days) in the high-exposure group. Among the variables that affected the duration of the acute respiratory symptoms, which were analyzed by using the Cox proportional hazard model, only exposure level was significant (hazard ratio 2.087, 95 % CI = 1.119, 3.890). Regarding the evacuation-related behaviors, 22 workers (47 %) voluntarily evacuated to a safety zone immediately after recognizing the accidental exposure, but 25 workers (43 %) delayed evacuation until the start of mandatory evacuation (min 5, max 25 min). The duration of the subjective acute respiratory symptoms significantly differed between the low- and high-exposure groups. Among the 27 workers in the high-exposure group, 17 misjudged the toxicity after being aware of the gas leakage, which is a relatively high number.

  3. Is There an Association Between Lifetime Cumulative Exposure and Acute Pulmonary Responses to Ozone?

    PubMed Central

    Arjomandi, Mehrdad; Tager, Ira B.; Bastaki, Maria; Chen, Connie; Holland, Nina; Balmes, John R.

    2012-01-01

    Objective To investigate the potential effects of lifetime cumulative ozone (O3) exposure on acute pulmonary responses to O3. Methods Fifteen healthy subjects from a larger cohort of young adults were exposed to 200 ppb O3 for 4 hours followed by bronchoscopy and bronchoalveolar lavage 18 hours later. Lung function, symptom questionnaires, and blood samples were obtained before and after each exposure. Subjects’ lifetime cumulative O3 exposures were estimated from residential histories and air-quality monitoring data. Results Acute exposure to O3 caused decrements in forced expiratory volume in 1 second (FEV1), maximal mid-expiratory flow rate (FEF25–75), and forced expiratory flow rate at 75% of forced vital capacity (FEF75), and an increase in plasma clara cell protein (CC16) level. Changes in CC16 and lower respiratory symptoms, but not in lung function, were positively correlated with lifetime cumulative O3 exposure. Conclusion Higher lifetime cumulative O3 exposure was associated with airway injury and respiratory symptom responses, but not with airway inflammatory or lung function responses, to acute O3 exposure. PMID:18332784

  4. Is there an association between lifetime cumulative exposure and acute pulmonary responses to ozone?

    PubMed

    Arjomandi, Mehrdad; Tager, Ira B; Bastaki, Maria; Chen, Connie; Holland, Nina; Balmes, John R

    2008-03-01

    To investigate the potential effects of lifetime cumulative ozone (O3) exposure on acute pulmonary responses to O3. Fifteen healthy subjects from a larger cohort of young adults were exposed to 200 ppb O3 for 4 hours followed by bronchoscopy and bronchoalveolar lavage 18 hours later. Lung function, symptom questionnaires, and blood samples were obtained before and after each exposure. Subjects' lifetime cumulative O3 exposures were estimated from residential histories and air-quality monitoring data. Acute exposure to O3 caused decrements in forced expiratory volume in 1 second (FEV1), maximal mid-expiratory flow rate (FEF25-75), and forced expiratory flow rate at 75% of forced vital capacity (FEF75), and an increase in plasma clara cell protein (CC16) level. Changes in CC16 and lower respiratory symptoms, but not in lung function, were positively correlated with lifetime cumulative O3 exposure. Higher lifetime cumulative O3 exposure was associated with airway injury and respiratory symptom responses, but not with airway inflammatory or lung function responses, to acute O3 exposure.

  5. Prenatal cortisol exposure predicts infant cortisol response to acute stress.

    PubMed

    O'Connor, Thomas G; Bergman, Kristin; Sarkar, Pampa; Glover, Vivette

    2013-03-01

    Experimental animal findings suggest that early stress and glucocorticoid exposure may program the function of the hypothalamic-pituitary-adrenal (HPA) axis in the offspring. The extension of these findings to human development is not yet clear. A prospective longitudinal study was conducted on 125 mothers and their normally developing children. Amniotic fluid was obtained at, on average, 17.2 weeks gestation; infant behavior and cortisol response to a separation-reunion stress was assessed at 17 months. Amniotic fluid cortisol predicted infant cortisol response to separation-reunion stress: infants who were exposed to higher levels of cortisol in utero showed higher pre-stress cortisol values and blunted response to stress exposure. The association was independent of prenatal, obstetric, and socioeconomic factors and child-parent attachment. The findings provide some of the strongest data in humans that HPA axis functioning in the child may be predicted from prenatal cortisol exposure.

  6. Distinct Profiles of Anxiety and Dysphoria during Spontaneous Withdrawal from Acute Morphine Exposure

    PubMed Central

    Rothwell, Patrick E.; Thomas, Mark J.; Gewirtz, Jonathan C.

    2009-01-01

    The negative motivational aspects of withdrawal include symptoms of both anxiety and depression, and emerge following termination of chronic drug use as well as after acute drug exposure. States of acute withdrawal are an inherent part of intermittent drug use in humans, but the contribution of acute withdrawal to the development of addiction has received limited systematic investigation, due to a lack of preclinical models for withdrawal states that emerge spontaneously after acute drug exposure. Here, we have characterized a spontaneous increase in the magnitude of the acoustic startle reflex (i.e., spontaneous withdrawal-potentiated startle) that emerges following acute morphine administration in rats, and compared the time course of startle potentiation and place conditioning. We find that startle potentiation appears related to a decrease in opiate receptor occupancy and reflects an anxiety-like state with a pharmacological profile similar to other signs of opiate withdrawal. Spontaneous startle potentiation emerges before the rewarding effects of morphine have subsided, even though naloxone administration after a single morphine exposure causes both startle potentiation and conditioned place aversion (CPA). These results demonstrate that negative emotional signs of withdrawal develop following just one exposure to morphine, and are likely a recurrent aspect of intermittent drug use that may contribute to the earliest adaptations underlying the development of addiction. Furthermore, the dissociation between spontaneous startle potentiation and CPA suggests anxiogenic and dysphoric manifestations of opiate withdrawal may be mediated by distinct neural mechanisms that are progressively engaged as withdrawal unfolds. PMID:19494807

  7. Acute exacerbation of idiopathic pulmonary fibrosis associated with air pollution exposure.

    PubMed

    Johannson, Kerri A; Vittinghoff, Eric; Lee, Kiyoung; Balmes, John R; Ji, Wonjun; Kaplan, Gilaad G; Kim, Dong Soon; Collard, Harold R

    2014-04-01

    Acute exacerbations of idiopathic pulmonary fibrosis are associated with high mortality and are of unknown cause. The effect of air pollution on exacerbations of interstitial lung disease is unknown. This study aims to define the association of air pollution exposure with acute exacerbation of idiopathic pulmonary fibrosis. Patients with idiopathic pulmonary fibrosis and corresponding air pollution data were identified from a longitudinal cohort. Air pollution exposures were assigned to each patient for ozone, nitrogen dioxide, particulate matter, sulfur dioxide and carbon monoxide based on geo-coded residential addresses. Cox proportional hazards models were used to estimate the association of air pollution exposures and acute exacerbations. Acute exacerbation was significantly associated with antecedent 6-week increases in mean level, maximum level and number of exceedances above accepted standards of ozone (hazard ratio (HR) 1.57, 95% CI 1.09-2.24; HR 1.42, 95% CI 1.11-1.82; and HR 1.51, 95% CI 1.17-1.94, respectively) and nitrogen dioxide (HR 1.41, 95% CI 1.04-1.91; HR 1.27, 95% CI 1.01-1.59; and HR 1.20, 95% CI 1.10-1.31, respectively). Increased ozone and nitrogen dioxide exposure over the preceding 6 weeks was associated with an increased risk of acute exacerbation of idiopathic pulmonary fibrosis, suggesting that air pollution may contribute to the development of this clinically meaningful event.

  8. Acute and chronic respiratory effects of occupational exposure to ammonia.

    PubMed

    Holness, D L; Purdham, J T; Nethercott, J R

    1989-12-01

    In a soda ash plant, 58 workers exposed to mean airborne ammonia levels of 9.2 +/- 1.4 ppm were compared with 31 control workers with a mean exposure of 0.3 +/- 0.1 ppm. There were no differences between the groups in the reporting of respiratory or cutaneous symptoms, sense of smell, baseline lung function, or change in lung function over a work shift at the beginning and end of a workweek. No relationships between level or length of ammonia exposure and lung function results were demonstrated.

  9. Cumulative exposure to prior collective trauma and acute stress responses to the Boston marathon bombings.

    PubMed

    Garfin, Dana Rose; Holman, E Alison; Silver, Roxane Cohen

    2015-06-01

    The role of repeated exposure to collective trauma in explaining response to subsequent community-wide trauma is poorly understood. We examined the relationship between acute stress response to the 2013 Boston Marathon bombings and prior direct and indirect media-based exposure to three collective traumatic events: the September 11, 2001 (9/11) terrorist attacks, Superstorm Sandy, and the Sandy Hook Elementary School shooting. Representative samples of residents of metropolitan Boston (n = 846) and New York City (n = 941) completed Internet-based surveys shortly after the Boston Marathon bombings. Cumulative direct exposure and indirect exposure to prior community trauma and acute stress symptoms were assessed. Acute stress levels did not differ between Boston and New York metropolitan residents. Cumulative direct and indirect, live-media-based exposure to 9/11, Superstorm Sandy, and the Sandy Hook shooting were positively associated with acute stress responses in the covariate-adjusted model. People who experience multiple community-based traumas may be sensitized to the negative impact of subsequent events, especially in communities previously exposed to similar disasters. © The Author(s) 2015.

  10. Effect of Hypohydration and Altitude Exposure on Aerobic Exercise Performance and Acute Mountain Sickness

    DTIC Science & Technology

    2010-09-01

    Am. Physiol. Soc., 1996, sect. 4, vol. II, chapt. 55, p. 1277–1289. 23a.Institute of Medicine. Water. In: Dietary Reference Intakes for Water...expressed across time, was not different among the four trials. Total fluid intakes (ml) over the 8-h exposure were 893 242, 743 146, 853 418... Potassium , Sodium, Chloride, and sulfate. Washington, DC: Institute of Medicine 2005, p. 73–185. 24. Kanner AA, Marchi N, Fazio V, Mayberg MR, Koltz MT

  11. Impacts of acute imipramine treatment on plasma and brain amino acid metabolism in mice given graded levels of dietary chicken protein.

    PubMed

    Nagasawa, Mao; Murakami, Tatsuro; Tomonaga, Shozo; Sato, Mikako; Takahata, Yoshihisa; Morimatsu, Fumiki; Furuse, Mitsuhiro

    2012-12-01

    Several studies have shown a relationship between depression and animal protein intake. To evaluate whether the difference of dietary chicken protein levels induces an antidepressant-like effect and potentiates acute antidepressant effects, three levels of dietary chicken protein were used as the representative animal protein with imipramine used as the antidepressant. In addition, the effects of dietary chicken protein on brain metabolism were evaluated. Open field test (OFT) and forced swimming test (FST) were conducted on the 27th and 28th days, respectively. OFT and FST were not influenced by both imipramine and dietary protein levels. However, characteristic effects of imipramine treatment on brain monoamine metabolism were observed in the cerebral cortex and hypothalamus. In addition, dietary protein significantly increased taurine and L-ornithine levels even though these amino acids were not contained in the diets. In conclusion, the metabolism of several amino acids in the plasma and brain were altered by dietary chicken protein.

  12. Silver bioaccumulation dynamics in a freshwater invertebrate after aqueous and dietary exposures to nanosized and ionic Ag

    USGS Publications Warehouse

    le Croteau, Marie-Noe; Misra, Superb K.; Luoma, Samuel N.; Valsami-Jones, Eugenia

    2011-01-01

    We compared silver (Ag) bioavailability and toxicity to a freshwater gastropod after exposure to ionic silver (Ag+) and to Ag nanoparticles (Ag NPs) capped with citrate or with humic acid. Silver form, exposure route, and capping agent influence Ag bioaccumulation dynamics in Lymnaea stagnalis. Snails efficiently accumulated Ag from all forms after either aqueous or dietary exposure. For both exposure routes, uptake rates were faster for Ag+ than for Ag NPs. Snails efficiently assimilated Ag from Ag NPs mixed with diatoms (assimilation efficiency (AE) ranged from 49 to 58%) and from diatoms pre-exposed to Ag+ (AE of 73%). In the diet, Ag NPs damaged digestion. Snails ate less and inefficiently processed the ingested food, which adversely impacted their growth. Loss rates of Ag were faster after waterborne exposure to Ag NPs than after exposure to dissolved Ag+. Once Ag was taken up from diet, whether from Ag+ or Ag NPs, Ag was lost extremely slowly. Large Ag body concentrations are thus expected in L. stagnalis after dietborne exposures, especially to citrate-capped Ag NPs. Ingestion of Ag associated with particulate materials appears as the most important vector of uptake. Nanosilver exposure from food might trigger important environmental risks.

  13. Acute Exposure to Particulate Matter (PM) Alters Physiologic ...

    EPA Pesticide Factsheets

    Human exposure to ambient PM from fossil-fuel emissions is linked to cardiovascular disease and death. This association strengthens in people with preexisting cardiopulmonary diseases—especially heart failure (HF). We previously examined the effects of PM on HF by exposing Spontaneously Hypertensive Heart Failure (SHHF) rats to residual oil fly ash (ROFA) after accelerating HF onset via isoproterenol (ISO) infusion. In that study, rats were exposed to PM 2 wks after ISO treatment ceased, which was more than 1 wk after ISO-cessation had induced a 9-d period of hypotension. Epidemiological evidence suggests that effects would be more pronounced if exposure coincided with the HF-like hypotensive period. We hypothesized that PM exposure shortly after cessation of ISO treatment would cause greater cardiopulmonary injury. SHHF rats were infused with ISO (n=24; 1.0 mg/kg/d sc) or saline (n=23) via osmotic pump for 5 wks and then 5 d later exposed by nose-only inhalation for 4 h to either air or 580 µg/m3 of the PM2.5 fraction of a synthetic PM (dried salt solution, MSO4) similar in composition to a well-studied ROFA and consisting of Fe, Ni and V sulfates. In ISO-pretreated rats only, MSO4 decreased pulse pressure (an indirect indicator of cardiac output), decreased systolic and diastolic blood pressures, and increased QA interval (inversely related to myocardial contractility) during inhalation exposure and caused post-inhalation pulmonary inflammation significantl

  14. Toxicogenomic identification of biomarkers of acute respiratory exposure sensitizing agents

    EPA Science Inventory

    Allergy induction requires multiple exposures to an agent. Therefore the development of high-throughput or in vitro assays for effective screening of potential sensitizers will require the identification of biomarkers. The goal of this preliminary study was to identify potential ...

  15. Toxicogenomic identification of biomarkers of acute respiratory exposure sensitizing agents

    EPA Science Inventory

    Allergy induction requires multiple exposures to an agent. Therefore the development of high-throughput or in vitro assays for effective screening of potential sensitizers will require the identification of biomarkers. The goal of this preliminary study was to identify potential ...

  16. Acute neuroactive drug exposures alter locomotor activity in larval zebrafish

    EPA Science Inventory

    In an effort to develop a rapid in vivo screen for EPA's prioritization of toxic chemicals, we are characterizing the locomotor activity of zebrafish (Danio rerio) larvae after exposure to prototypic drugs that act on the central nervous system. MPTP (1-methyl-4phenyl- 1 ,2,3,6-...

  17. Acute neuroactive drug exposures alter locomotor activity in larval zebrafish

    EPA Science Inventory

    In an effort to develop a rapid in vivo screen for EPA's prioritization of toxic chemicals, we are characterizing the locomotor activity of zebrafish (Danio rerio) larvae after exposure to prototypic drugs that act on the central nervous system. MPTP (1-methyl-4phenyl- 1 ,2,3,6-...

  18. USE OF PHARMACOKINETIC MODELING FOR DIETARY EXPOSURE STUDY DESIGN AND MODEL EVALUATION

    EPA Science Inventory

    It has been shown that young children have potentially higher dietary pesticide intake when they handle foods while eating. Foods become contaminated with pesticides from "dirty" hands and home surfaces. A dietary intake model has been developed to estimate the potential increa...

  19. USE OF PHARMACOKINETIC MODELING FOR DIETARY EXPOSURE STUDY DESIGN AND MODEL EVALUATION

    EPA Science Inventory

    It has been shown that young children have potentially higher dietary pesticide intake when they handle foods while eating. Foods become contaminated with pesticides from "dirty" hands and home surfaces. A dietary intake model has been developed to estimate the potential increa...

  20. Dietary exposure and risk assessment of mercury from the Korean total diet study.

    PubMed

    Kwon, Young Min; Lee, Haeng Shin; Yoo, Dong Chul; Kim, Chun Huem; Kim, Gi Sun; Kim, Ji Ae; Lee, Yu Na; Kim, Young Soon; Kang, Kyung Mo; No, Ki Mi; Paek, Ock Jin; Seo, Jung Hyuk; Choi, Hoon; Park, Sung Kug; Choi, Dong Mi; Kim, Dong Sul; Choi, Dal Woong

    2009-01-01

    As a national project, obtaining information on the amount of heavy metal exposure of individuals through food intake is an important basic parameter for risk assessment. This study was conducted to evaluate dietary exposure levels and various risks from mercury (Hg) in Korean foods. In total, 342 samples comprising 114 food items were collected and then cooked prior to analysis. As found by Hg analysis, the mean content of metal in the fish and shellfish group was highest among the 15 Korean food groups. The total daily amount of Hg intake from typical Korean foods was 2.40 microg/person/d. The daily amount (microg/person/d) of Hg intake from each food group was 0.155 in grains and cereals, 0.008 potatoes and starch, 0.005 sugars and sweets, 0.0093 pulses, 0.0018 nuts and seeds, 0.203 vegetables, 0.027 fruits, 0.021 meats and poultry, 0.004 eggs, 1.826 fish and shellfish, 0.022 seaweed, 0.043 milk and dairy products, 0.008 oils and fats, 0.042 beverages, and 0.023 seasonings. The fish and shellfish group contributed most to total dietary intake at 76%. For risk assessment, probable daily intake (PDI) was calculated and compared with provisional tolerable weekly intake (PTWI) of the Joint FAO/WHO Expert Committee on Food Additives (JECFA). The level of Hg intake through fish and shellfish of 0.001 mg/kg body weight bw/wk corresponded to 4.54% of the PTWI value of 0.005 mg/kg bw/wk, the safety standard for JECFA. The level of Hg intake through selected foods from the Food list for Koreans was 0.001 mg/kg bw/wk, corresponding to 5.95% of PTWI value. Therefore, overall intake was at levels below the recommended JECFA levels. The relative gender Hg hazard from Korean foods was 6.26% and 5.5% for males and females, respectively. The relative age Hg hazard from Korean foods was, 8.9% in those 3-6 yr old, 6.7% in those 7-12 yr old, 5.2% in those 13-19 yr old, 5.9% in those 20-29 yr old, 6.3% in those 30-49 yr old, 5.6% in those ages 50-64 yr, and 3.7% in the group of

  1. Assessment of dietary exposure to trace metals in Baffin Inuit food.

    PubMed Central

    Chan, H M; Kim, C; Khoday, K; Receveur, O; Kuhnlein, H V

    1995-01-01

    Chronic metal toxicity is a concern in the Canadian Arctic because of the findings of high metal levels in wildlife animals and the fact that traditional food constitutes a major component of the diet of indigenous peoples. We examined exposure to trace metals through traditional food resources for Inuit living in the community of Qikiqtarjuaq on Baffin Island in the eastern Arctic. Mercury, cadmium, and lead were determined in local food resources as normally prepared and eaten. Elevated concentrations of mercury ( > 50 micrograms/100 g) were found in ringed seal liver, narwhal mattak, beluga meat, and beluga mattak, and relatively high concentrations of cadmium and lead ( > 100 micrograms/100 g) were found in ringed seal liver, mussels, and kelp. Quantified dietary recalls taken seasonally reflected normal consumption patterns of these food resources by adult men and women ( > 20 years old) and children (3-12 years old). Based on traditional food consumption, the average daily intake levels of total mercury for both adults (65 micrograms for women and 97 micrograms for men) and children (38 micrograms) were higher than the Canadian average value (16 micrograms). The average weekly intake of mercury for all age groups exceeded the intake guidelines (5.0 micrograms/kg/day) established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives and Contaminants. The primary foods that contributed to metal intake for the Baffin Inuit were ringed seal meat, caribou meat, and kelp. We review the superior nutritional benefits and potential health risks of traditional food items and implications for monitoring metal contents of food, clinical symptoms, and food use. Images Figure 1. PMID:7588487

  2. Low dietary cyanogen exposure from frequent consumption of potentially toxic cassava in Malawi.

    PubMed

    Chiwona-Karltun, L; Tylleskär, T; Mkumbira, J; Gebre-Medhin, M; Rosling, H

    2000-01-01

    In a cassava-growing area in Malawi, where roots are processed by soaking and water is available throughout the year, we interviewed 176 women farmers regarding their preferences for cassava cultivars and frequency of cassava consumption. Dietary cyanogen exposure was estimated from urinary levels of linamarin, the cyanogenic glycoside in cassava, and urinary thiocyanate, the main cyanide metabolite. Protection against unplanned harvest by family members, theft and animal spoilage were stated to be very important reasons for growing bitter cassava cultivars by 91%, 90% and 74% of the women, respectively. The mean (+/- SD) number of cultivars grown by each woman was 4.6 (+/- 2.4). The correlation between mean taste and mean danger scores for the 25 most grown cultivars was strong (r > 0.98). The scoring indicated that cultivars belonged to two distinct groups, eight to a group referred to as 'cool' and 17 to a group termed 'bitter'. The dumpling-like porridge (kondowole) made from cassava flour from bitter roots was eaten twice daily by 51% and at least weekly by 81%. The mean (+/- SEM) urinary linamarin was 14 (+/- 1) mumol/L and thiocyanate was 50 (+/- 4) mumol/L, less than a tenth of levels reported from populations eating insufficiently processed bitter cassava roots, and in the same range as in a non-smoking Swedish reference population. We conclude that cyanogenesis is a preferred characteristic of cassava by the studied farmers because it enhances food security. The availability of water and their knowledge about toxicity and processing enables these women farmers to provide a safe staple food from bitter cassava roots.

  3. Human health risk assessment of DDTs and HCHs through dietary exposure in Nanjing, China.

    PubMed

    Zhang, Qianqian; Xia, Zhonghuan; Wu, Minmin; Wang, Liping; Yang, Hao

    2017-06-01

    In a market based study in Nanjing, a typical southeast city in China, the most common consumed 23 kinds of foods from eleven different categories (vegetable, fruit, fish, pork, livestock meat, chicken, egg, milk, oil, rice and flour) were sampled in November 2015. The concentrations of DDTs and HCHs in foods were analyzed using gas chromatography with mass spectrometer detector. The residual amounts of DDTs and HCHs in foods were 0.95-3.53 ng g(-1) and 0.32-1.96 ng g(-1), respectively. The highest residual of ∑10OCPs was 4.75 ng g(-1) in livestock meat and the lowest was 1.31 ng g(-1) in flour. Estimated daily intakes of both DDTs and HCHs for children were higher than other age groups regardless of the gender. With respect to food categories, the consumption of vegetables generated higher dietary exposure of DDTs and HCHs than other food categories for all age categories, which accounted for 20.21%-29.18% of the total. The daily intakes of γ-HCH and DDTs for all population groups were far below the acceptable amounts suggested by the Food and Agriculture Organization of the United Nations/World Health Organization. Health risk assessment indicated that there was no obvious non-cancer risk for local residents, whereas the cancer risk was estimated to be from 10(-6)∼10(-4), being higher than the acceptable risk level and lower than the priority risk level. Among residents of different gender and age, females showed higher risk than males in all age groups, and children were the most vulnerable age group to health risk. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Occurrence of and dietary exposure to parabens in foodstuffs from the United States.

    PubMed

    Liao, Chunyang; Liu, Fang; Kannan, Kurunthachalam

    2013-04-16

    Parabens are esters of p-hydroxybenzoic acid and are widely used as preservatives in cosmetics, pharmaceuticals, foodstuffs, including beverages. Information on the occurrence of parabens in foodstuffs and dietary exposure of humans to these chemicals is not available. In this study, food samples (n = 267) collected from Albany, New York, United States, were grouped into eight categories, namely, beverages, dairy products, fats and oils, fish and shellfish, grains, meat, fruits, and vegetables, and analyzed for five parabens by high-performance liquid chromatography-tandem mass spectrometry. The majority (>90%) of food samples contained measurable concentrations of parabens, and the total concentrations (Σparabens; sum of five parabens) ranged from below the limit of quantitation to 409 ng/g fresh weight (mean: 9.67 ng/g; median: 0.92 ng/g). Methyl-, ethyl-, and propyl-parabens were the predominant compounds, accounting for ∼90% of the total concentrations. Butyl- and benzyl-parabens were less frequently detected. There were no significant differences in paraben concentrations among the eight food categories, including the canned foods. On the basis of the concentrations measured and per capita daily ingestion rates of foods, we estimated the daily intake (EDI; ng/kg of body weight (bw)/day)) of parabens through food ingestion. The EDI values of total parabens (calculated from the mean concentrations measured and the mean daily ingestion rates of food items) were 940, 879, 470, 273, and 307 ng/kg bw/day for infants, toddlers, children, teenagers, and adults, respectively. To our knowledge, this is the first study to report the occurrence of parabens in foodstuffs.

  5. Occurrence of parabens in foodstuffs from China and its implications for human dietary exposure.

    PubMed

    Liao, Chunyang; Chen, Lingxin; Kannan, Kurunthachalam

    2013-07-01

    Parabens are alkyl esters of p-hydroxybenzoic acid and are used as antimicrobial preservatives in a range of consumer products, including cosmetics, pharmaceuticals, and foodstuffs. Despite their widespread use, prior to this study, paraben concentrations in foodstuffs from China and human dietary exposure to these chemicals have been unknown. In this study, concentrations of six parabens were determined in 13 categories of food samples (n=282), including cereals and cereal products, meat, fish and seafood, eggs, dairy products, bean products, fruits, vegetables, cookies, beverages, cooking oils, condiments, and others, collected from nine cities in China. Almost all (detection rate: 99%) food samples contained at least one of the parabens analyzed, and the total concentrations (ΣParabens; sum of six parabens) ranged from below limit of quantification (LOQ) to 2530ng/g fresh weight, with an overall mean value of 39.3ng/g. Methyl paraben (MeP), ethyl paraben (EtP), and propyl paraben (PrP) were the major paraben analogs found in foodstuffs, and these compounds accounted for 59%, 24%, and 10%, respectively, of ΣParaben concentrations. Although the mean concentrations of ΣParabens varied among different categories of food items (from 0.839ng/g in beverages to 100ng/g in vegetables), the concentrations were not statistically significant among the 13 food categories, including canned foodstuffs. Estimated daily intake (EDI) of parabens was based on the measured concentrations in foods and the corresponding daily food ingestion rates. The mean and 95th percentile values for EDI were 1010 and 3040ng/kg body weight (bw)/day for adult men and 1060 and 3170ng/kg bw/day for adult women, respectively. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Effects of chronic dietary petroleum exposure on reproductive development in polar cod (Boreogadus saida).

    PubMed

    Bender, Morgan Lizabeth; Frantzen, Marianne; Vieweg, Ireen; Falk-Petersen, Inger-Britt; Johnsen, Helge Kreutzer; Rudolfsen, Geir; Tollefsen, Knut Erik; Dubourg, Paul; Nahrgang, Jasmine

    2016-11-01

    Increasing human activities in the Arctic raise the risk of petroleum pollution, thus posing an elevated risk for Arctic organisms to be chronically exposed to petroleum compounds. The endocrine disrupting properties of some of these compounds (i.e. polycyclic aromatic hydrocarbons [PAHs]) present in crude oil may have negative effects on the long and energy intensive reproductive development of polar cod (Boreogadus saida), an Arctic keystone species. In the present study, selected reproductive parameters were examined in feral polar cod exposed to crude oil via a natural diet (0.11, 0.57 and 1.14μg crude oil/g fish/day [corresponding to low, medium and high treatments, respectively]) for 31 weeks prior to spawning. Fish maturing in the current reproductive period made up 92% of the experimental population while 5% were immature and 3% were identified as resting fish. Phase I metabolism of PAHs, indicated by ethoxyresorufin-O-deethylase (EROD) activity, showed a dose-dependent increase in high and medium crude oil treatments at week 6 and 22, respectively. Decreasing EROD activity and increasing PAH bile metabolite concentrations over the experimental period may be explained by reproductive maturity stage. Significant alterations in sperm motility were observed in crude oil exposed males compared to the controls. The investigated somatic indices (gonad and hepatic), germ cell development and plasma steroid levels (estradiol-17β [females], testosterone [males and females] and 11-ketotestosterone [males]) were not significantly altered by chronic dietary exposure to crude oil. The environmentally realistic doses polar cod were chronically exposed to in this study were likely not high enough to induce adverse effects in this ecologically important fish species. This study elucidated many baseline aspects of polar cod reproductive physiology and emphasized the influence of maturation state on biomarkers of PAH biotransformation (EROD and PAH bile metabolites).

  7. Natural Occurrence of Alternaria Toxins in Wheat-Based Products and Their Dietary Exposure in China

    PubMed Central

    Zhao, Kai; Shao, Bing; Yang, Dajin; Li, Fengqin; Zhu, Jianghui

    2015-01-01

    A total of 181 wheat flour and 142 wheat-based foods including dried noodle, steamed bread and bread collected in China were analyzed for alternariol (AOH), alternariol monomethyl ether (AME), tentoxin (TEN) and tenuazonic acid (TeA) by ultra-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. TeA was the predominant toxin found in 99.4% wheat flour samples at levels ranging from 1.76 μg/kg to 520 μg/kg. TEN was another Alternaria toxin frequently detected in wheat flour samples (97.2%) at levels between 2.72 μg/kg and 129 μg/kg. AOH and AME were detected in 11 (6.1%) samples at levels ranging from 16.0 μg/kg to 98.7 μg/kg (AOH) and in 165 (91.2%) samples with a range between 0.320 μg/kg and 61.8 μg/kg (AME). AOH was quantified at higher levels than AME with the ratio of AOH/AME ranging from 1.0 to 3.7. Significant linear regressions of correlation in toxin concentrations were observed between AOH and AME, AME and TeA, TEN and TeA, AOH+AME and TeA. At an average and 95th percentile, dietary exposure to AOH and AME in the Chinese general population and different age subgroups exceeded the relevant threshold value of toxicological concern (TTC), with the highest exposure found in children which deserves human health concern. TEN and TeA seem unlikely to be health concerns for the Chinese via wheat-based products but attention should be paid to synergistic or additive effects of TeA with AOH, AME, TEN and a further assessment will be performed once more data on toxicity-guided fractionation of the four toxins are available. It is necessary to conduct a systemic surveillance of Alternaria toxins in raw and processed foods in order to provide the scientific basis for making regulations on these toxins in China. PMID:26121047

  8. Short term hardening effects on survival of acute and chronic cold exposure by Drosophila melanogaster larvae

    PubMed Central

    Rajamohan, Arun; Sinclair, Brent J.

    2008-01-01

    We quantified the variation and plasticity in cold tolerance among four larval stages of four laboratory strains of Drosophila melanogaster in response to both acute (<2 hours of cold exposure) and chronic (∼7 hours of cold exposure) cold exposure. We observed significant differences in basal cold tolerance between the strains and among larval stages. Early larval instars were generally more tolerant of acute cold exposures than 3rd instar larvae. However, wandering larvae were more tolerant of chronic cold exposures than the other stages. Early stages also displayed a more pronounced rapid cold-hardening response than the later stages. Heat pre-treatment did not confer a significant increase in cold tolerance to any of the strains at any stage, pointing to different mechanisms being involved in resolving heat- and cold-elicited damage. However, when heat pre-treatment was combined with rapid cold-hardening as sequential pre-treatments, both positive (heat first) and negative (heat second) effects on cold tolerance were observed. We discuss possible mechanisms underlying cold-hardening and the effects of acute and chronic cold exposures. PMID:18342328

  9. Cardiac Autonomic Effects of Acute Exposures to Airborne Particulates in Men and Women

    NASA Technical Reports Server (NTRS)

    Howarth, M. S.; Schlegel, T. T.; Knapp, C. F.; Patwardhan, A. R.; Jenkins, R. A.; Ilgner, R. H.; Evans, J. M.

    2007-01-01

    The aim of this research was to investigate cardiac autonomic changes associated with acute exposures to airborne particulates. Methods: High fidelity 12-lead ECG (CardioSoft, Houston, TX) was acquired from 19 (10 male / 9 female) non-smoking volunteers (age 33.6 +/- 6.6 yrs) during 10 minutes pre-exposure, exposure and post-exposure to environmental tobacco smoke (ETS), cooking oil fumes, wood smoke and sham (water vapor). To control exposure levels, noise, subject activity, and temperature, all studies were conducted inside an environmental chamber. Results: The short-term fractal scaling exponent (Alpha-1) and the ratio of low frequency to high frequency Heart Rate Variability (HRV) powers (LF/HF, a purported sympathetic index) were both higher in males (p<0.017 and p<0.05, respectively) whereas approximate entropy (ApEn) and HF/(LF+HF) (a purported parasympathetic index) were both lower in males (p<0.036, and p<0.044, respectively). Compared to pre-exposure (p<0.0002) and sham exposure (p<0.047), male heart rates were elevated during early ETS post-exposure. Our data suggest that, in addition to tonic HRV gender differences, cardiac responses to some acute airborne particulates are gender related.

  10. Acute nitrite exposure alters the metabolism of thyroid hormones in grass carp (Ctenopharyngodon idellus).

    PubMed

    Xiao, Chen; Liu, Zidong; Li, Dapeng; Refaey, Mohamed M; Tang, Rong; Li, Li; Zhang, Xi

    2017-08-08

    Nitrite has the potential to disturb thyroid hormone homeostasis, but little is known about the underlying mechanisms. In the present study, juvenile grass carp (Ctenopharyngodon idellus) were exposed to various concentrations of nitrite (0, 0.5, 1, 4, and 16 mg/L, respectively). Serum concentrations of triiodothyronine (T3), thyroxine (T4), free triiodothyronine (FT3), free thyroxine (FT4), 3,3,5'-triiodothyronine (rT3), thyroid-stimulating hormone (TSH), and the activity of iodothyronine deiodinases were assayed at 0, 12, 24, 48, and 96 h after exposure. It was found that acute nitrite exposure significantly altered the TH levels and iodothyronine deiodinase activities. The rT3 levels were significantly increased in the treatment groups, whereas the concentrations of T3, FT3, FT4, and TSH decreased significantly. The concentration of T4 was elevated in the lower-dose exposure group, but was reduced in the higher-dose exposure group. Increases in type I iodothyronine deiodinase (ID1) and type III iodothyronine deiodinase (ID3) activities were observed in the exposure groups. The activity of type II iodothyronine deiodinase (ID2) decreased at 12 and 24 h after exposure. A decrease of colloid in the thyroid follicles was observed in the exposure group. The results indicate that acute nitrite exposure has the potential to disturb the homeostasis of thyroid hormone metabolism, leading to a hypothyroidism state in the juvenile grass carp. Copyright © 2017. Published by Elsevier Ltd.

  11. Chronic and Acute Effects of Coal Tar Pitch Exposure and Cardiopulmonary Mortality Among Aluminum Smelter Workers

    PubMed Central

    Friesen, Melissa C.; Demers, Paul A.; Spinelli, John J.; Eisen, Ellen A.; Lorenzi, Maria F.; Le, Nhu D.

    2010-01-01

    Air pollution causes several adverse cardiovascular and respiratory effects. In occupational studies, where levels of particulate matter and polycyclic aromatic hydrocarbons (PAHs) are higher, the evidence is inconsistent. The effects of acute and chronic PAH exposure on cardiopulmonary mortality were examined within a Kitimat, Canada, aluminum smelter cohort (n = 7,026) linked to a national mortality database (1957–1999). No standardized mortality ratio was significantly elevated compared with the province's population. Smoking-adjusted internal comparisons were conducted using Cox regression for male subjects (n = 6,423). Ischemic heart disease (IHD) mortality (n = 281) was associated with cumulative benzo[a]pyrene (B(a)P) exposure (hazard ratio = 1.62, 95% confidence interval: 1.06, 2.46) in the highest category. A monotonic but nonsignificant trend was observed with chronic B(a)P exposure and acute myocardial infarction (n = 184). When follow-up was restricted to active employment, the hazard ratio for IHD was 2.39 (95% confidence interval: 0.95, 6.05) in the highest cumulative B(a)P category. The stronger associations observed during employment suggest that risk may not persist after exposure cessation. No associations with recent or current exposure were observed. IHD was associated with chronic (but not current) PAH exposure in a high-exposure occupational setting. Given the widespread workplace exposure to PAHs and heart disease's high prevalence, even modest associations produce a high burden. PMID:20702507

  12. The bioaccumulation and effects of selenium in the oligochaete Lumbriculus variegatus via dissolved and dietary exposure routes.

    PubMed

    Xie, Lingtian; Wu, Xing; Chen, Hongxing; Luo, Yongju; Guo, Zhongbao; Mu, Jingli; Blankson, Emmanuel R; Dong, Wu; Klerks, Paul L

    2016-09-01

    Aquatic organisms take up selenium from solution and from their diets. Many questions remain regarding the relative importance of selenium accumulation from these sources and resulting effects in benthic invertebrates. The present study addressed the toxicity and accumulation of Se via dissolved and dietary exposures to three different Se species, in the freshwater oligochaete Lumbriculus variegatus. Worms were exposed to 20μg/g dry weight of selenite (Se(IV)), selenate (Se(VI)), or seleno-l-methionine (Se-Met) in their diet (sediment) or to 15μg/L dissolved Se in water-only exposures. While the dissolved and sediment Se levels differed greatly, such levels may co-occur at a Se-contaminated site. Se accumulation, worm population growth, lipid peroxidation (as TBARS), and Na(+)/K(+)-ATPase activity were quantified at the end of the 2-week exposure. The sediment Se-Met exposure caused 100% mortality, while worm densities were reduced by the other exposures except the Se(VI) one. Se bioaccumulation was generally higher for the sediment-Se exposure than the dissolved-Se ones, and was higher for Se(IV) than Se(VI) in the dissolved-Se exposure but not the sediment-Se one. The Se accumulation was highest for Se-Met. The oligochaetes that accumulated Se had higher levels of lipid peroxidation and reduced Na(+)/K(+)-ATPase activity. The present study's findings of differences in Se accumulation and toxicity for the three Se species, with effects generally but not exclusively a function of Se body burdens, underscore the need for research on these issues in invertebrates. Moreover, the results imply that the dietary uptake route is the predominant one for Se accumulation in L. variegatus.

  13. Differences of acute versus chronic ethanol exposure on anxiety-like behavioral responses in zebrafish.

    PubMed

    Mathur, Priya; Guo, Su

    2011-06-01

    Zebrafish, a vertebrate model organism amenable to high throughput screening, is an attractive system to model and study the mechanisms underlying human diseases. Alcoholism and alcoholic medical disorders are among the most debilitating diseases, yet the mechanisms by which ethanol inflicts the disease states are not well understood. In recent years zebrafish behavior assays have been used to study learning and memory, fear and anxiety, and social behavior. It is important to characterize the effects of ethanol on zebrafish behavioral repertoires in order to successfully harvest the strength of zebrafish for alcohol research. One prominent effect of alcohol in humans is its effect on anxiety, with acute intermediate doses relieving anxiety and withdrawal from chronic exposure increasing anxiety, both of which have significant contributions to alcohol dependence. In this study, we assess the effects of both acute and chronic ethanol exposure on anxiety-like behaviors in zebrafish, using two behavioral paradigms, the Novel Tank Diving Test and the Light/Dark Choice Assay. Acute ethanol exposure exerted significant dose-dependent anxiolytic effects. However, withdrawal from repeated intermittent ethanol exposure disabled recovery from heightened anxiety. These results demonstrate that zebrafish exhibit different anxiety-like behavioral responses to acute and chronic ethanol exposure, which are remarkably similar to these effects of alcohol in humans. Because of the accessibility of zebrafish to high throughput screening, our results suggest that genes and small molecules identified in zebrafish will be of relevance to understand how acute versus chronic alcohol exposure have opposing effects on the state of anxiety in humans. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Acute Air Pollution Exposure and Risk of Suicide Completion

    PubMed Central

    Bakian, Amanda V.; Huber, Rebekah S.; Coon, Hilary; Gray, Douglas; Wilson, Phillip; McMahon, William M.; Renshaw, Perry F.

    2015-01-01

    Research into environmental factors associated with suicide has historically focused on meteorological variables. Recently, a heightened risk of suicide related to short-term exposure to airborne particulate matter was reported. Here, we examined the associations between short-term exposure to nitrogen dioxide, particulate matter, and sulfur dioxide and completed suicide in Salt Lake County, Utah (n = 1,546) from 2000 to 2010. We used a time-stratified case-crossover design to estimate adjusted odds ratios for the relationship between suicide and exposure to air pollutants on the day of the suicide and during the days preceding the suicide. We observed maximum heightened odds of suicide associated with interquartile-range increases in nitrogen dioxide during cumulative lag 3 (average of the 3 days preceding suicide; odds ratio (OR) = 1.20, 95% confidence interval (CI): 1.04, 1.39) and fine particulate matter (diameter ≤2.5 μm) on lag day 2 (day 2 before suicide; OR = 1.05, 95% CI: 1.01, 1.10). Following stratification by season, an increased suicide risk was associated with exposure to nitrogen dioxide during the spring/fall transition period (OR = 1.35, 95% CI: 1.09, 1.66) and fine particulate matter in the spring (OR = 1.28, 95% CI: 1.01, 1.61) during cumulative lag 3. Findings of positive associations between air pollution and suicide appear to be consistent across study locations with vastly different meteorological, geographical, and cultural characteristics. PMID:25673816

  15. Mutagenic potential of acute exposure to organophosphorus and organochlorine compounds.

    PubMed

    Vijayaraghavan, M; Nagarajan, B

    1994-04-01

    The cytogenetic and cytotoxic effects of the pesticides methyl parathion, Bayleton and Hinosan were evaluated in mammalian test systems. The frequency of chromosome aberrations and micronuclei in bone marrow cells and the arginase enzyme profile in the liver tend to show the genotoxicity of organophosphorus and organochlorine pesticides in a single-exposure response study. Methyl parathion was the most hazardous among the three, showing definite pathology in the livers of treated rats.

  16. Dietary squalene supplementation improves DSS-induced acute colitis by downregulating p38 MAPK and NFkB signaling pathways.

    PubMed

    Sánchez-Fidalgo, Susana; Villegas, Isabel; Rosillo, Maria Ángeles; Aparicio-Soto, Marina; de la Lastra, Catalina Alarcón

    2015-02-01

    Squalene is a polyunsaturated triterpene, which has exhibited anticancer and antioxidant activities among others. We investigated dietary squalene supplementation effect on an acute colitis model induced by dextran sulfate sodium (DSS) in C57BL/6 mice. Mice were fed from weaning with squalene at 0.02% and 0.1%. After 4 weeks, mice were exposed to 3% DSS for 5 days developing acute colitis. After DSS removal (5 days), colons were histological and biochemically processed. Our results showed that dietary squalene treatment exerts anti-inflammatory action in DSS-induced acute colitis. Western blot revealed that squalene downregulated COX-2 (where COX is cyclooxygenase) and inducible nitric oxide synthase system by inhibition of mitogen-activated protein kinase p38 and the nuclear factor-kappa B signaling pathways, preventing an increase in the cytokines levels. Under our experimental conditions, STAT3 and FOXP3 (where FOXP3 is forkhead box P3) were not modified and the transcriptional regulation of antioxidant and/or detoxifying enzymes, Nrf2 (where Nrf2 is nuclear factor (erythroid-derived 2)-like 2), was reduced in DSS-induced colitis. However, any change could be observed after squalene supplementation. Squalene was able to improve the oxidative events and returned proinflammatory proteins expression to basal levels probably through p38 mitogen-activated protein kinase and nuclear factor-kappa B signaling pathways. However, supplementary studies are needed in order to provide a basis for developing a new dietary supplementation strategy. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Acute exposure of apigenin induces hepatotoxicity in Swiss mice.

    PubMed

    Singh, Prabhat; Mishra, Shrawan Kumar; Noel, Sanjeev; Sharma, Sharad; Rath, Srikanta Kumar

    2012-01-01

    Apigenin, a dietary flavonoid, is reported to have several therapeutic effects in different diseases including cancer. Toxicity of Apigenin is however, least explored, and reports are scanty in literature. This warrants dose-specific evaluation of toxicity in vivo. In the present study, Apigenin was administered intraperitoneally to Swiss mice at doses of 25, 50, 100 and 200 mg/kg. Serum levels of alanine amino transferase (ALT), aspartate amino transferase (AST) and alkaline phosphatase (ALP) were measured along with the examination of liver histology, reactive oxygen species (ROS) in blood, lipid peroxidation (LPO), glutathione level, superoxide dismutase activity, catalase activity, glutathione S-transferase activity and gene expression in liver tissue. Increase in ALT, AST, ALP, ROS, ratio of oxidized to reduced glutathione (GSSG/GSH) and LPO, altered enzyme activities along with damaged histoarchitecture in the liver of 100 or 200 mg/kg Apigenin treated animals were found. Microarray analysis revealed the differential expression of genes that correspond to different biologically relevant pathways including oxidative stress and apoptosis. In conclusion, these results suggested the oxidative stress induced liver damage which may be due to the regulation of multiple genes by Apigenin at higher doses in Swiss mice.

  18. Acute illness-induced behavioral alterations are similar to those observed during withdrawal from acute alcohol exposure

    PubMed Central

    Richey, Laura; Doremus-Fitzwater, Tamara L.; Buck, Hollin M.; Deak, Terrence

    2012-01-01

    Exposure to an immunogen results in a constellation of behavioral changes collectively referred to as “sickness behaviors,” with alterations in cytokine expression previously shown to contribute to this sickness response. Since behaviors observed during ethanol withdrawal are strikingly similar to sickness behaviors, we hypothesized that behavioral manifestations of ethanol withdrawal might be an expression of sickness behaviors induced by ethanol-related changes in peripheral and/or central cytokine expression. Accordingly, behaviors exhibited during a modified social investigation test were first characterized in male rats following an acute injection of lipopolysaccharide (LPS; 100 μg/kg). Subsequently, behavioral changes after either a high (4-g/kg; Experiment 2) or low dose (0.5 g/kg; Experiment 3) of ethanol were also examined in the same social investigation test, as well as in the forced-swim test (FST; Experiment 4). Results from these experiments demonstrated similar reductions in both exploration and social investigatory behavior during acute illness and ethanol withdrawal, while a seemingly paradoxical decrease in immobility was observed in the FST during acute ethanol withdrawal. In follow-up studies, neither indomethacin (Experiment 5) nor interleukin-1 receptor antagonist (Experiment 6) pre-exposure reversed the ethanol withdrawal-induced behavioral changes observed in this social investigation test. Taken together, these studies demonstrate that the behavioral sequelae of acute illness and ethanol withdrawal are similar in nature, while antagonist studies suggest that these behavioral alterations are not reversed by blockade of IL-1 receptors or inhibition of prostaglandin synthesis. Though a direct mechanistic link between cytokines and the expression of acute ethanol withdrawal-related behaviors has yet to be found, future studies examining the involvement of brain cytokines as potential mediators of ethanol effects are greatly needed. PMID

  19. DISTRIBUTION OF 14C-ATRAZINE FOLLOWING AN ACUTE LACTATIONAL EXPOSURE IN THE WISTAR RAT.

    EPA Science Inventory

    The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg 14C-atrazine (14C-ATR) by gavage. 14C-ATR was administered to the nursing dam on postnatal day 3 by oral gavag...

  20. The effect of chronic ammonia exposure on acute phase proteins, immunoglobulin and cytokines in laying hens

    USDA-ARS?s Scientific Manuscript database

    Ammonia is a potential health hazard to both humans and animals, causing systemic low-grade inflammation based on its levels and durations. The objective of this study was to examine the effect of 45 weeks of exposure to 30 ppm NH3 on the concentrations of acute phase proteins, immunoglobulins and c...

  1. Self-reported acute health symptoms and exposure to companion animals#

    EPA Science Inventory

    Self-reported acute health symptoms and exposure to companion animalsWhitney S. Krueger1,2, Elizabeth D. Hilborn2, Timothy J. Wade21Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA2Environmental Public Health Division, Office of Research and Development, U...

  2. Neurobehavorial effects of acute exposure to four solvents: meta-abalyses

    EPA Science Inventory

    Meta-and re-analyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. (2007). The present study was designed to test the generality of the toluene results in as many other solvents as possible by furthe...

  3. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  4. DISTRIBUTION OF 14C-ATRAZINE FOLLOWING AN ACUTE LACTATIONAL EXPOSURE IN THE WISTAR RAT.

    EPA Science Inventory

    The purpose of the present study was to examine the distribution of atrazine in the lactating dam and suckling neonate following an acute exposure to either 2 or 4 mg/kg 14C-atrazine (14C-ATR) by gavage. 14C-ATR was administered to the nursing dam on postnatal day 3 by oral gavag...

  5. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    EPA Science Inventory

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  6. CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC

    EPA Science Inventory

    CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC. UP Kodavanti, MC Schladweiler, AD Ledbetter, RH Jaskot, PS Gilmour, DC Christiani, WP Watkinson, DL Costa, JK McGee, A Nyska. NHEERL, USEPA, RTP, NC; CEMALB, UNC, Chapel Hil...

  7. Striatal dopamine dynamics in mice following acute and repeated toluene exposure.

    PubMed

    Apawu, Aaron K; Mathews, Tiffany A; Bowen, Scott E

    2015-01-01

    The abused inhalant toluene has potent behavioral effects, but only recently has progress been made in understanding the neurochemical actions that mediate the action of toluene in the brain. Available evidence suggests that toluene inhalation alters dopamine (DA) neurotransmission, but toluene's mechanism of action is unknown. The present study evaluated the effect of acute and repeated toluene inhalation (0, 2,000, or 4,000 ppm) on locomotor activity as well as striatal DA release and uptake using slice fast-scan cyclic voltammetry. Acutely, 2,000 and 4,000 ppm toluene increased locomotor activity, while neurochemically only 4,000 ppm toluene potentiated electrically evoked DA release across the caudate-putamen and the nucleus accumbens. Repeated administration of toluene resulted in sensitization to toluene's locomotor activity effects. Brain slices obtained from mice repeatedly exposed to toluene demonstrated no difference in stimulated DA release in the caudate-putamen as compared to control animals. Repeated exposure to 2,000 and 4,000 ppm toluene caused a concentration-dependent decrease of 25-50 % in evoked DA release in the nucleus accumbens core and shell relative to air-exposed mice. These voltammetric neurochemical findings following repeated toluene exposure suggest that there may be a compensatory downregulation of the DA system. Acute or repeated toluene exposure had no effect on the DA uptake kinetics. Taken together, these results demonstrate that acute toluene inhalation potentiates DA release, while repeated toluene exposure attenuates DA release in the nucleus accumbens only.

  8. In Utero Exposure to Lipopolysaccharide Alters the Postnatal Acute Phase Response in Beef Heifers

    USDA-ARS?s Scientific Manuscript database

    This study was designed to determine the potential effect of prenatal lipopolysaccharide (LPS) exposure on the postnatal acute phase response (APR) to an LPS challenge in heifers. Pregnant crossbred cows (n = 50) were separated into prenatal immune stimulation (PIS; n = 25; administered 0.1 microgr...

  9. TOXICITY PATHWAY ANALYSIS IN AGING BROWN NORWAY RAT BRAIN FOLLOWING ACUTE TOLUENE EXPOSURE

    EPA Science Inventory

    The influence of aging on susceptibility to environmental stressors is poorly understood. To investigate the contribution of different life stages on response to toxicants, we examined the effects of acute exposure by oral gavage of the volatile organic solvent toluene (0.00, 0.3...

  10. Neurobehavorial effects of acute exposure to four solvents: meta-abalyses

    EPA Science Inventory

    Meta-and re-analyses of the available data for the neurobehavioral effects of acute inhalation exposure to toluene were reported by Benignus et al. (2007). The present study was designed to test the generality of the toluene results in as many other solvents as possible by furthe...

  11. CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC

    EPA Science Inventory

    CARDIOVASCULAR INJURY FROM ACUTE AND REPEATED EXPOSURE TO PARTICULATE MATTER (PM): POTENTIAL ROLE OF ZINC. UP Kodavanti, MC Schladweiler, AD Ledbetter, RH Jaskot, PS Gilmour, DC Christiani, WP Watkinson, DL Costa, JK McGee, A Nyska. NHEERL, USEPA, RTP, NC; CEMALB, UNC, Chapel Hil...

  12. Self-reported acute health symptoms and exposure to companion animals#

    EPA Science Inventory

    Self-reported acute health symptoms and exposure to companion animalsWhitney S. Krueger1,2, Elizabeth D. Hilborn2, Timothy J. Wade21Oak Ridge Institute for Science and Education, Oak Ridge, Tennessee, USA2Environmental Public Health Division, Office of Research and Development, U...

  13. ACUTE BEHAVORIAL EFFECTS FROM EXPOSURE TO TWO-STROKE ENGINE EXHAUST

    EPA Science Inventory

    Benefits of changing from two-stroke to four-stroke engines (and other remedial requirements) can be evaluated (monetized) from the standpoint of acute behavioral effects of human exposure to exhaust from these engines. The monetization process depends upon estimates of the magn...

  14. High dietary iron increases oxidative stress and radiosensitivity in the rat retina and vasculature after exposure to fractionated gamma radiation

    PubMed Central

    Theriot, Corey A; Westby, Christian M; Morgan, Jennifer L L; Zwart, Sara R; Zanello, Susana B

    2016-01-01

    Radiation exposure in combination with other space environmental factors including microgravity, nutritional status, and deconditioning is a concern for long-duration space exploration missions. Astronauts experience altered iron homeostasis due to adaptations to microgravity and an iron-rich food system. Iron intake reaches three to six times the recommended daily allowance due to the use of fortified foods on the International Space Station. Iron is associated with certain optic neuropathies and can potentiate oxidative stress. This study examined the response of eye and vascular tissue to gamma radiation exposure (3 Gy fractionated at 37.5 cGy per day every other day for 8 fractions) in rats fed an adequate-iron diet or a high-iron diet. Twelve-week-old Sprague-Dawley rats were assigned to one of four experimental groups: adequate-iron diet/no radiation (CON), high-iron diet/no radiation (IRON), adequate-iron diet/radiation (RAD), and high-iron diet/radiation (IRON+RAD). Animals were maintained on the corresponding iron diet for 2 weeks before radiation exposure. As previously published, the high-iron diet resulted in elevated blood and liver iron levels. Dietary iron overload altered the radiation response observed in serum analytes, as evidenced by a significant increase in catalase levels and smaller decrease in glutathione peroxidase and total antioxidant capacity levels. 8-OHdG immunostaining, showed increased intensity in the retina after radiation exposure. Gene expression profiles of retinal and aortic vascular samples suggested an interaction between the response to radiation and high dietary iron. This study suggests that the combination of gamma radiation and high dietary iron has deleterious effects on retinal and vascular health and physiology. PMID:28725729

  15. A Method for Quantifying the Acute Health Impacts of Residential Non-Biological Exposure Via Inhalation

    SciTech Connect

    Logue, Jennifer M.; Sherman, Max H.; Singer, Bret C.

    2014-08-01

    The inability to monetize the health costs of acute exposures in homes and the benefits of various control options is a barrier to justifying policies and approaches that can reduce exposure and improve health.We synthesized relationships between short-term outdoor concentration changes and health outcomes to estimate the health impacts of short-term in-home exposures. Damage and cost impacts of specific health outcomes were taken from the literature. We assessed the impact of vented and non-vented residential natural gas cooking burners on Southern California occupants for two pollutants (NO2 and CO).

  16. Acute exposure to waterborne psychoactive drugs attract zebrafish.

    PubMed

    Abreu, Murilo S; Giacomini, Ana Cristina V; Gusso, Darlan; Rosa, João G S; Koakoski, Gessi; Kalichak, Fabiana; Idalêncio, Renan; Oliveira, Thiago A; Barcellos, Heloísa H A; Bonan, Carla D; Barcellos, Leonardo J G

    2016-01-01

    Psychotropic medications are widely used, and their prescription has increased worldwide, consequently increasing their presence in aquatic environments. Therefore, aquatic organisms can be exposed to psychotropic drugs that may be potentially dangerous, raising the question of whether these drugs are attractive or aversive to fish. To answer this question, adult zebrafish were tested in a chamber that allows the fish to escape or seek a lane of contaminated water. These attraction and aversion paradigms were evaluated by exposing the zebrafish to the presence of acute contamination with these compounds. The zebrafish were attracted by certain concentrations of diazepam, fluoxetine, risperidone and buspirone, which were most likely detected by olfaction, because this behavior was absent in anosmic fish. These findings suggest that despite their deleterious effects, certain psychoactive drugs attract fish. Copyright © 2015 Elsevier Inc. All rights reserved.

  17. Glucocorticoid exposure alters the pathogenesis of Theiler’s murine encephalomyelitis virus during acute infection

    PubMed Central

    Young, Erin E.; Prentice, Thomas W.; Satterlee, Danielle; McCullough, Heath; Sieve, Amy N.; Johnson, Robin R.; Welsh, Thomas H.; Welsh, C. Jane R.; Meagher, Mary W.

    2008-01-01

    Previous research has shown that chronic restraint stress exacerbates Theiler’s virus infection, a murine model for CNS inflammation and multiple sclerosis. The current set of experiments was designed to evaluate the potential role of glucocorticoids in the deleterious effects of restraint stress on acute CNS inflammatory disease. Exposure to chronic restraint stress resulted in elevated levels of corticosterone as well as increased clinical scores and weight loss (Experiment 1). In addition, corticosterone administration alone exacerbated behavioral signs of TMEV-induced sickness (i.e. decreased body weight, increased symptoms of encephalitis, and increased mortality) and reduced inflammation in the CNS (Experiment 2). Infected subjects receiving exogenous corticosterone showed exacerbation of acute phase measures of sickness and severe mortality as well as decreased viral clearance from CNS (Experiment 3). These findings indicate that corticosterone exposure alone is sufficient to exacerbate acute CNS inflammatory disease. PMID:18538803

  18. Dietary exposure to trace elements and radionuclides: the methodology of the Italian Total Diet Study 2012-2014.

    PubMed

    D'Amato, Marilena; Turrini, Aida; Aureli, Federica; Moracci, Gabriele; Raggi, Andrea; Chiaravalle, Eugenio; Mangiacotti, Michele; Cenci, Telemaco; Orletti, Roberta; Candela, Loredana; di Sandro, Alessandra; Cubadda, Francesco

    2013-01-01

    This article presents the methodology of the Italian Total Diet Study 2012-2014 aimed at assessing the dietary exposure of the general Italian population to selected nonessential trace elements (Al, inorganic As, Cd, Pb, methyl-Hg, inorganic Hg, U) and radionuclides (40K, 134Cs, 137Cs, 90Sr). The establishment of the TDS food list, the design of the sampling plan, and details about the collection of food samples, their standardized culinary treatment, pooling into analytical samples and subsequent sample treatment are described. Analytical techniques and quality assurance are discussed, with emphasis on the need for speciation data and for minimizing the percentage of left-censored data so as to reduce uncertainties in exposure assessment. Finally the methodology for estimating the exposure of the general population and of population subgroups according to age (children, teenagers, adults, and the elderly) and gender, both at the national level and for each of the four main geographical areas of Italy, is presented.

  19. Quantifying children's aggregate (dietary and residential) exposure and dose to permethrin: application and evaluation of EPA's probabilistic SHEDS-Multimedia model.

    PubMed

    Zartarian, Valerie; Xue, Jianping; Glen, Graham; Smith, Luther; Tulve, Nicolle; Tornero-Velez, Rogelio

    2012-01-01

    Reliable, evaluated human exposure and dose models are important for understanding the health risks from chemicals. A case study focusing on permethrin was conducted because of this insecticide's widespread use and potential health effects. SHEDS-Multimedia was applied to estimate US population permethrin exposures for 3- to 5-year-old children from residential, dietary, and combined exposure routes, using available dietary consumption data, food residue data, residential concentrations, and exposure factors. Sensitivity and uncertainty analyses were conducted to identify key factors, pathways, and research needs. Model evaluation was conducted using duplicate diet data and biomonitoring data from multiple field studies, and comparison to other models. Key exposure variables were consumption of spinach, lettuce, and cabbage; surface-to-skin transfer efficiency; hand mouthing frequency; fraction of hand mouthed; saliva removal efficiency; fraction of house treated; and usage frequency. For children in households using residential permethrin, the non-dietary exposure route was most important, and when all households were included, dietary exposure dominated. SHEDS-Multimedia model estimates compared well to real-world measurements data; this exposure assessment tool can enhance human health risk assessments and inform children's health research. The case study provides insights into children's aggregate exposures to permethrin and lays the foundation for a future cumulative pyrethroid pesticides risk assessment.

  20. Including non-dietary sources into an exposure assessment of the European Food Safety Authority: The challenge of multi-sector chemicals such as Bisphenol A.

    PubMed

    von Goetz, N; Pirow, R; Hart, A; Bradley, E; Poças, F; Arcella, D; Lillegard, I T L; Simoneau, C; van Engelen, J; Husoy, T; Theobald, A; Leclercq, C

    2017-04-01

    In the most recent risk assessment for Bisphenol A for the first time a multi-route aggregate exposure assessment was conducted by the European Food Safety Authority. This assessment includes exposure via dietary sources, and also contributions of the most important non-dietary sources. Both average and high aggregate exposure were calculated by source-to-dose modeling (forward calculation) for different age groups and compared with estimates based on urinary biomonitoring data (backward calculation). The aggregate exposure estimates obtained by forward and backward modeling are in the same order of magnitude, with forward modeling yielding higher estimates associated with larger uncertainty. Yet, only forward modeling can indicate the relative contribution of different sources. Dietary exposure, especially via canned food, appears to be the most important exposure source and, based on the central aggregate exposure estimates, contributes around 90% to internal exposure to total (conjugated plus unconjugated) BPA. Dermal exposure via thermal paper and to a lesser extent via cosmetic products may contribute around 10% for some age groups. The uncertainty around these estimates is considerable, but since after dermal absorption a first-pass metabolism of BPA by conjugation is lacking, dermal sources may be of equal or even higher toxicological relevance than dietary sources. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. Prenatal and acute cocaine exposure affects neural responses and habituation to visual stimuli

    PubMed Central

    Riley, Elizabeth; Kopotiyenko, Konstantin; Zhdanova, Irina

    2015-01-01

    Psychostimulants have many effects on visual function, from adverse following acute and prenatal exposure to therapeutic on attention deficit. To determine the impact of prenatal and acute cocaine exposure on visual processing, we studied neuronal responses to visual stimuli in two brain regions of a transgenic larval zebrafish expressing the calcium indicator GCaMP-HS. We found that both red light (LF) and dark (DF) flashes elicited similar responses in the optic tectum neuropil (TOn), while the dorsal telencephalon (dTe) responded only to LF. Acute cocaine (0.5 μM) reduced neuronal responses to LF in both brain regions but did not affect responses to DF. Repeated stimulus presentation (RSP) led to habituation of dTe neurons to LF. Acute cocaine prevented habituation. TOn habituated to DF, but not LF, and DF habituation was not modified by cocaine. Remarkably, prenatal cocaine exposure (PCE) prevented the effects of acute cocaine on LF response amplitude and habituation later in development in both brain regions, but did not affect DF responses. We discovered that, in spite of similar neural responses to LF and DF in the TO (superior colliculus in mammals), responses to LF are more complex, involving dTe (homologous to the cerebral cortex), and are more vulnerable to cocaine. Our results demonstrate that acute cocaine exposure affects visual processing differentially by brain region, and that PCE modifies zebrafish visual processing in multiple structures in a stimulus-dependent manner. These findings are in accordance with the major role that the optic tectum and cerebral cortex play in sustaining visual attention, and support the hypothesis that modification of these areas by PCE may be responsible for visual deficits noted in humans. This model offers new methodological approaches for studying the adverse and therapeutic effects of psychostimulants on attention, and for the development of new pharmacological interventions. PMID:26379509

  2. Responses of the soft coral Xenia elongata following acute exposure to a chemical dispersant.

    PubMed

    Studivan, Michael S; Hatch, Walter I; Mitchelmore, Carys L

    2015-01-01

    Limited toxicology data are available regarding oil dispersant exposure to coral species. Corexit® EC9500A (Corexit) is a commonly applied dispersant most well known for its use after the Deepwater Horizon spill in April, 2010. There is limited evidence that Corexit can cause a bleaching response in corals. The aims of the study were: (1) to determine the extent of bleaching after acute 24 h and 72 h exposures of sublethal concentrations (0-50 ppm) of Corexit to the pulsing soft coral Xenia elongata and (2) to investigate a percent symbiont loss calculation using zooxanthellae density. The percent symbiont loss calculation was compared to a traditional metric of normalizing zooxanthellae density to soluble protein content. Percent symbiont loss was an effective measure of coral stress in acute Corexit exposures, while protein normalized zooxanthellae density was more variable. The bleaching data suggest a positive relationship between dispersant concentration and percent symbiont loss, culminating in excessive tissue necrosis and coral mortality within 72 h in high concentration exposures (p < 0.001). Percent beaching ranged from 25% in 5 ppm exposures to 100% in 50 ppm exposures. Corexit also caused a significant decrease in pulse activity (p < 0.0001) and relative oxygen saturation (p < 0.001), possibly indicating a reduction in photosynthetic efficiency. This study and other similar research indicate that dispersant exposure is highly damaging to marine organisms, including ecologically important coral species.

  3. USE OF A PHYSIOLOGICALLY BASED TOXICOKINETIC MODEL TO SIMULATE CHRONIC DIETARY EXPOSURE IN FISH

    EPA Science Inventory

    A physiologically based toxicokinetic (PBTK) model was developed to describe dietary uptake of hydrophobic organic chemicals by fish. The GI tract was modeled as four compartments corresponding to the stomach, pyloric ceca, upper intestine, and lower intestine. Partitioning coeff...

  4. USE OF A PHYSIOLOGICALLY BASED TOXICOKINETIC MODEL TO SIMULATE CHRONIC DIETARY EXPOSURE IN FISH

    EPA Science Inventory

    A physiologically based toxicokinetic (PBTK) model was developed to describe dietary uptake of hydrophobic organic chemicals by fish. The GI tract was modeled as four compartments corresponding to the stomach, pyloric ceca, upper intestine, and lower intestine. Partitioning coeff...

  5. Accumulation of cadmium in the otoliths and tissues of juvenile pink snapper (Pagrus auratus Forster) following dietary and waterborne exposure.

    PubMed

    Ranaldi, Melinda Marie; Gagnon, Marthe Monique

    2009-11-01

    Laboratory experiments were conducted to examine if incorporation of Cd into the otoliths of juvenile pink snapper (Pagrus auratus Forster) was related to levels in the food or water. In the first experiment, fish were fed a regular diet (control group) or a Cd-contaminated diet (500mgCdkg(-1) or 1500mgCdkg(-1)) for 35days. In the second experiment, fish were exposed to waterborne Cd concentrations of <0.002microgL(-1) (control), 50microgL(-1), 100microgL(-1) and 150microgL(-1) for 35days. The sagittal otoliths were analysed using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Juvenile fish exposed to higher concentrations of waterborne or dietary Cd showed increased Cd levels in their otoliths. This study clearly demonstrated that both aqueous and dietary Cd exposures can result in Cd incorporation into the otoliths of pink snapper.

  6. Exhaled nitric oxide decreases upon acute exposure to high-altitude hypoxia.

    PubMed

    Brown, Daniel E; Beall, Cynthia M; Strohl, Kingman P; Mills, Phoebe S

    2006-01-01

    Nitric oxide (NO) is a vasodilator that plays a role in blood flow and oxygen delivery. Acute hypoxia down regulates NO synthesis, a response that may exacerbate hypoxic stress by decreasing blood flow. This study was designed to test the hypotheses that pulmonary NO decreases upon acute exposure to high-altitude hypoxia and that relatively low levels of NO at altitude are associated with greater stress as reflected in more symptoms of acute mountain sickness (AMS). A sample of 47 healthy, adult, nonsmoking, sea-level residents provided measurements at sea level, at 2,800 m, and at 0-, 2-, and 3-h exposure times at 4,200 m altitude on Mauna Kea, Hawaii. Measurements were made of exhaled NO, oxygen saturation of hemoglobin, heart rate, and reported symptoms of AMS. The partial pressure of NO concentration in exhaled breath decreased significantly from a sea level mean of 4.2 nmHg to 3.8 nmHg at 2,800 m and 3.4 nmHg at 4,200 m. NO concentration in exhaled breath did not change significantly over a 3-h exposure at 4,200 m and recovered to pre-exposure baseline upon return to sea level. There was no significant association between the level of NO exhaled and the number of self-reported symptoms of AMS during this brief exposure. Am. J. Hum. Biol. 18:196-202, 2006. (c) 2006 Wiley-Liss, Inc.

  7. Dietary exposure to polychlorinated biphenyls and dioxins from infancy until adulthood: A comparison between breast-feeding, toddler, and long-term exposure.

    PubMed

    Patandin, S; Dagnelie, P C; Mulder, P G; Op de Coul, E; van der Veen, J E; Weisglas-Kuperus, N; Sauer, P J

    1999-01-01

    Food is the major source for polychlorinated biphenyl (PCB) and dioxin accumulation in the human body. Therefore, investigating food habits from early ages until reproductive age (25 years) is important in order to assess exposure risk for the next generation. The objective of this study was to assess the PCB/dioxin exposure and the relative contribution of different foods to total exposure during preschool age. Particularly, the importance of lactational PCB/dioxin exposure vs. dietary exposure until adulthood was investigated. A cohort of 207 children was studied from birth until preschool age. Based on 3 planar PCBs and 17 2,3,7,8-substituted dibenzo-para-dioxins (PCDDs) and dibenzofurans (PCDFs) measured in breast milk, a model was developed to calculate the cumulative toxic equivalent (TEQ) intake during breast-feeding (0-1 year). In 3. 5-year-old children, daily dietary intake of planar PCB-TEQ and dioxin-TEQ was measured with a validated food questionnaire. Cumulative TEQ intake from 1 to 5 years was estimated using the PCB- and dioxin-TEQ intake measured with the food questionnaire. Cumulative TEQ intake from 6 to 25 years was estimated using national food consumption and contamination data of PCB- and dioxin-TEQ intake. In toddlers, dairy products contributed 43% to PCB-TEQ and 50% to dioxin-TEQ intake. Meat and meat products contributed 14% and 19%, respectively, and processed foods 23% and 15%, respectively. Breast-feeding for 6 months contributed to the cumulative PCB/dioxin TEQ intake until 25 years of age, 12% in boys and 14% in girls. The daily TEQ intake per kilogram body weight is 50 times higher in breast-fed infants and three times higher in toddlers than in adults. Long-term dietary exposure to PCBs and dioxins in men and women is partly due to breast-feeding (12 and 14%, respectively). After weaning, dairy products, processed foods, and meat are major contributors of PCB and dioxin accumulation until reproductive age. Instead of discouraging

  8. Dietary exposure to polychlorinated biphenyls and dioxins from infancy until adulthood: A comparison between breast-feeding, toddler, and long-term exposure.

    PubMed Central

    Patandin, S; Dagnelie, P C; Mulder, P G; Op de Coul, E; van der Veen, J E; Weisglas-Kuperus, N; Sauer, P J

    1999-01-01

    Food is the major source for polychlorinated biphenyl (PCB) and dioxin accumulation in the human body. Therefore, investigating food habits from early ages until reproductive age (25 years) is important in order to assess exposure risk for the next generation. The objective of this study was to assess the PCB/dioxin exposure and the relative contribution of different foods to total exposure during preschool age. Particularly, the importance of lactational PCB/dioxin exposure vs. dietary exposure until adulthood was investigated. A cohort of 207 children was studied from birth until preschool age. Based on 3 planar PCBs and 17 2,3,7,8-substituted dibenzo-para-dioxins (PCDDs) and dibenzofurans (PCDFs) measured in breast milk, a model was developed to calculate the cumulative toxic equivalent (TEQ) intake during breast-feeding (0-1 year). In 3. 5-year-old children, daily dietary intake of planar PCB-TEQ and dioxin-TEQ was measured with a validated food questionnaire. Cumulative TEQ intake from 1 to 5 years was estimated using the PCB- and dioxin-TEQ intake measured with the food questionnaire. Cumulative TEQ intake from 6 to 25 years was estimated using national food consumption and contamination data of PCB- and dioxin-TEQ intake. In toddlers, dairy products contributed 43% to PCB-TEQ and 50% to dioxin-TEQ intake. Meat and meat products contributed 14% and 19%, respectively, and processed foods 23% and 15%, respectively. Breast-feeding for 6 months contributed to the cumulative PCB/dioxin TEQ intake until 25 years of age, 12% in boys and 14% in girls. The daily TEQ intake per kilogram body weight is 50 times higher in breast-fed infants and three times higher in toddlers than in adults. Long-term dietary exposure to PCBs and dioxins in men and women is partly due to breast-feeding (12 and 14%, respectively). After weaning, dairy products, processed foods, and meat are major contributors of PCB and dioxin accumulation until reproductive age. Instead of discouraging

  9. Effects of Acute Exposure to Sublethal Waterborne Cadmium on Energy Homeostasis in Silver Carp (Hypophthalmichthys molitrix).

    PubMed

    Pi, Jie; Li, Xuelin; Zhang, Ting; Li, Deliang

    2016-10-01

    Effects of acute exposure to sublethal waterborne cadmium (Cd) on energy homeostasis in filter-feeding fishes have rarely been studied. The response patterns of energy substances were investigated in juvenile silver carp (Hypophthalmichthys molitrix) exposed to sublethal waterborne Cd for 96 h. The results showed the 96hLC50 of Cd on juvenile silver carp was 1.723 mg/L. Sublethal acute exposure of Cd significantly affected the energy homeostasis of juvenile silver carp, including increase in plasma glucose and lactate, and decrease in plasma triglyceride, muscle glycogen and triglyceride and liver glycogen. The results indicated that glycogen and triglyceride prior to protein were mobilized to meet the increased demands for detoxication and repair mechanism to sublethal waterborne Cd exposure, and glycogen level depleted faster and restored slower in the liver than in the white muscle in juvenile silver carp.

  10. Association of habitual dietary resveratrol exposure with the development of frailty in older age: the Invecchiare in Chianti study12

    PubMed Central

    Rabassa, Montserrat; Zamora-Ros, Raul; Urpi-Sarda, Mireia; Bandinelli, Stefania; Ferrucci, Luigi; Andres-Lacueva, Cristina; Cherubini, Antonio

    2015-01-01

    Background: Resveratrol may play a protective role against the frailty syndrome (FS) because of its antioxidant and anti-inflammatory properties. Objective: We prospectively evaluated the association between habitual dietary resveratrol exposure and the development of FS after 3-, 6-, and 9-y follow-up periods in a community-dwelling older population. Design: We conducted a longitudinal analysis with the use of data from 769 participants aged ≥65 y from the Invecchiare in Chianti (Aging in Chianti) study. Total dietary resveratrol (TDR) intake was estimated at baseline with the use of a validated food-frequency questionnaire, which was developed to assess participants’ usual food intakes over the previous year, and an ad hoc resveratrol database. Total urinary resveratrol (TUR) was analyzed with the use of liquid chromatography–tandem mass spectrometry with a previous solid-phase extraction at baseline. The combination of both measures [total dietary resveratrol plus total urinary resveratrol (TDR+TUR)] was computed with the use of the Howe’s method. FS was assessed at baseline and at 3-, 6-, and 9-y of follow-up and was defined as the presence of ≥3 of the following 5 criteria: shrinking, exhaustion, sedentariness, slowness, and weakness. Results: TDR+TUR concentrations were inversely associated with FS risk over 3-y of follow-up (OR for comparison of extreme tertiles: 0.11; 95% CI: 0.03, 0.45; P-trend = 0.002) but not after 6- and 9-y of follow-up in multinomial logistic regression models adjusted for baseline frailty status and potential confounders. These results did not differ when analyses were further adjusted for inflammatory markers. Conclusion: Higher habitual dietary resveratrol exposure was associated with lower risk of older community dwellers developing FS during the first 3 y of follow-up but not after longer follow-up periods. PMID:26490492

  11. Dietary zinc mediates inflammation and protects against wasting and metabolic derangement caused by sustained cigarette smoke exposure in mice.

    PubMed

    Lang, Carol J; Hansen, Michelle; Roscioli, Eugene; Jones, Jessica; Murgia, Chiara; Leigh Ackland, Margaret; Zalewski, Peter; Anderson, Gary; Ruffin, Richard

    2011-02-01

    In mouse asthma models, inflammation can be modulated by zinc (Zn). Given that appetite loss, muscle wasting and poor nutrition are features of chronic obstructive pulmonary disease (COPD) and that poor dietary Zn intake is in itself accompanied by growth retardation and appetite loss, we hypothesised that dietary Zn limitation would not only worsen airway inflammation but also exaggerate metabolic effects of cigarette smoke (CS) exposure in mice. Conversely, Zn supplementation would lessen inflammation. Mice were exposed to CS [2× 2RF, 3×/day; 15 min/cigarette] and fed diets containing 2, 20 or 140 mg/kg Zn ad libitum. Airway cells were collected by bronchoalveolar lavage (BAL). Plasma Zn was measured by fluorometric assay. Inflammatory, metabolic and Zn transport markers were measured by real-time RT-PCR. Mice fed low Zn diets had less plasma labile zinc (0-0.18 μM) than mice fed moderate (0.61-0.98 μM) or high (0.77-1.1 μM) Zn diets (SDs 0.1-0.4, n = 8-10). Smoke exposure increased plasma and BAL labile Zn (1.5-2.5 fold, P < 0.001), bronchoalveolar macrophages (2.0 fold, P < 0.0001) and MT-1 (1.5 fold), MIP-2 (2.3 fold) and MMP-12 (3.5 fold) mRNA. Zn supplementation reduced alveolar macrophage numbers by 62 and 52% in sham and smoke-exposed mice, respectively (Zn effect: P = 0.011). Gastrocnemius, soleus and tibialis anterior muscle mass were affected by both smoke and dietary Zn in the order of 3-7%. The 50-60% reduction in alveolar macrophages in Zn-supplemented mice supports our evolving hypothesis that Zn is an important anti-inflammatory mediator of airway inflammation. Restoring airway Zn levels through dietary supplementation may lessen the severity of lung inflammation when Zn intake is low.

  12. Acute and Chronic Exposure to CO2 in Space Flight

    NASA Technical Reports Server (NTRS)

    Alexander, D.; Wu, J.; Barr, Y. R.; Watkins, S. D.

    2010-01-01

    Spacecraft and space stations, similar to other habitable confined spaces such as submarines, need to provide a breathable atmosphere for their inhabitants. The inevitable production of CO2 during respiration necessitates life support systems that "scrub" the atmosphere and lower CO2 levels. Due to operational limitations associated with space flight (limited mass, volume, power, and consumables) CO2 is not scrubbed down to its terrestrial equivalent of 0.03% CO2 (ppCO2 of 0.23 mmHg), but is kept below 0.7% (ppCO2 of 5.3 mmHg), a level established in NASA s 180-day mission Spacecraft Maximum Allowable Concentration (SMAC) to be safe and unlikely to cause symptoms. Reports of space flight crewmembers becoming symptomatic with headaches, fatigue, and malaise at levels below those known to cause such symptoms terrestrially has prompted studies measuring the levels of CO2 on both the space shuttle and the space station. Data from cabin atmosphere sampling were collected on space shuttle missions STS-113, STS-122, STS-123, and International Space Station Expeditions 12-15 and 17, and the measured CO2 levels were then correlated to symptoms reported by the crew. The results indicate that a correlation exists between CO2 levels and symptomatology, however causality cannot be established at this time. While the short-term effects of elevated CO2 exposure are well known terrestrially, less is known regarding potential long-term effects of prolonged exposure to a CO2-rich environment or how the physiological changes caused by microgravity may interact with such exposures. Other challenges include limitations in the CO2 monitors used, lack of convection in the microgravity environment, and formation of localized CO2 pockets. As it is unclear if the unique environment of space increases sensitivity to CO2 or if other confounding factors are present, further research is planned to elucidate these points. At the same time, efforts are underway to update the SMAC to a lower level

  13. Influence of cooking method on arsenic retention in cooked rice related to dietary exposure.

    PubMed

    Rahman, M Azizur; Hasegawa, H; Rahman, M Arifur; Rahman, M Mahfuzur; Miah, M A Majid

    2006-10-15

    Arsenic concentration in raw rice is not only the determinant in actual dietary exposure. Though there have been many reports on arsenic content in raw rice and different tissues of rice plant, little is known about arsenic content retained in cooked rice after being cooked following the traditional cooking methods employed by the people of arsenic epidemic areas. A field level experiment was conducted in Bangladesh to investigate the influence of cooking methods on arsenic retention in cooked rice. Rice samples were collected directly from a severely arsenic affected area and also from an unaffected area, to compare the results. Rice was cooked according to the traditional methods employed by the population of subjected areas. Arsenic concentrations were 0.40+/-0.03 and 0.58+/-0.12 mg/kg in parboiled rice of arsenic affected area, cooked with excess water and 1.35+/-0.04 and 1.59+/-0.07 mg/kg in gruel for BRRI dhan28 and BRRI hybrid dhan1, respectively. In non-parboiled rice, arsenic concentrations were 0.39+/-0.04 and 0.44+/-0.03 mg/kg in rice cooked with excess water and 1.62+/-0.07 and 1.74+/-0.05 mg/kg in gruel for BRRI dhan28 and BRRI hybrid dhan1, respectively. Total arsenic content in rice, cooked with limited water (therefore gruel was absorbed completely by rice) were 0.89+/-0.07 and 1.08+/-0.06 mg/kg (parboiled) and 0.75+/-0.04 and 1.09+/-0.06 mg/kg (non-parboiled) for BRRI dhan28 and BRRI hybrid dhan1, respectively. Water used for cooking rice contained 0.13 and 0.01 mg of As/l for contaminated and non-contaminated areas, respectively. Arsenic concentrations in cooked parboiled and non-parboiled rice and gruel of non-contaminated area were significantly lower (p<0.01) than that of contaminated area. The results imply that cooking of arsenic contaminated rice with arsenic contaminated water increases its concentration in cooked rice.

  14. Long-Term Ozone Exposure Increases the Risk of Developing the Acute Respiratory Distress Syndrome.

    PubMed

    Ware, Lorraine B; Zhao, Zhiguo; Koyama, Tatsuki; May, Addison K; Matthay, Michael A; Lurmann, Fred W; Balmes, John R; Calfee, Carolyn S

    2016-05-15

    The contribution of air pollution to the risk of acute respiratory distress syndro