Probabilistic models to estimate fire-induced cable damage at nuclear power plants

NASA Astrophysics Data System (ADS)

Valbuena, Genebelin R.

Even though numerous PRAs have shown that fire can be a major contributor to nuclear power plant risk, there are some specific areas of knowledge related to this issue, such as the prediction of fire-induced damage to electrical cables and circuits, and their potential effects in the safety of the nuclear power plant, that still constitute a practical enigma, particularly for the lack of approaches/models to perform consistent and objective assessments. This report contains a discussion of three different models to estimate fire-induced cable damage likelihood given a specified fire profile: the kinetic, the heat transfer and the IR "K Factor" model. These models not only are based on statistical analysis of data available in the open literature, but to the greatest extent possible they use physics based principles to describe the underlying mechanism of failures that take place among the electrical cables upon heating due to external fires. The characterization of cable damage, and consequently the loss of functionality of electrical cables in fire is a complex phenomenon that depends on a variety of intrinsic factors such as cable materials and dimensions, and extrinsic factors such as electrical and mechanical loads on the cables, heat flux severity, and exposure time. Some of these factors are difficult to estimate even in a well-characterized fire, not only for the variability related to the unknown material composition and physical arrangements, but also for the lack of objective frameworks and theoretical models to study the behavior of polymeric wire cable insulation under dynamic external thermal insults. The results of this research will (1) help to develop a consistent framework to predict fire-induced cable failure modes likelihood, and (2) develop some guidance to evaluate and/or reduce the risk associated with these failure modes in existing and new power plant facilities. Among the models evaluated, the physics-based heat transfer model takes into account the properties and characteristics of the cables and cable materials, and the characteristics of the thermal insult. This model can be used to estimate the probability of cable damage under different thermal conditions.

Measuring behaviours for escaping from house fires: use of latent variable models to summarise multiple behaviours.

PubMed

Ploubidis, G B; Edwards, P; Kendrick, D

2015-12-15

This paper reports the development and testing of a construct measuring parental fire safety behaviours for planning escape from a house fire. Latent variable modelling of data on parental-reported fire safety behaviours and plans for escaping from a house fire and multivariable logistic regression to quantify the association between groups defined by the latent variable modelling and parental-report of having a plan for escaping from a house fire. Data comes from 1112 participants in a cluster randomised controlled trial set in children's centres in 4 study centres in the UK. A two class model provided the best fit to the data, combining responses to five fire safety planning behaviours. The first group ('more behaviours for escaping from a house fire') comprised 86% of participants who were most likely to have a torch, be aware of how their smoke alarm sounds, to have external door and window keys accessible, and exits clear. The second group ('fewer behaviours for escaping from a house fire') comprised 14% of participants who were less likely to report these five behaviours. After adjusting for potential confounders, participants allocated to the 'more behaviours for escaping from a house fire group were 2.5 times more likely to report having an escape plan (OR 2.48; 95% CI 1.59-3.86) than those in the "fewer behaviours for escaping from a house fire" group. Multiple fire safety behaviour questions can be combined into a single binary summary measure of fire safety behaviours for escaping from a house fire. Our findings will be useful to future studies wishing to use a single measure of fire safety planning behaviour as measures of outcome or exposure. NCT 01452191. Date of registration 13/10/2011.

77 FR 37717 - Electrical Cable Test Results and Analysis During Fire Exposure

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-22

... Fire Exposure AGENCY: Nuclear Regulatory Commission. ACTION: Draft NUREG; request for comment. SUMMARY...-2128, ``Electrical Cable Test Results and Analysis during Fire Exposure (ELECTRA-FIRE), A Consolidation of the Three Major Fire-Induced Circuit and Cable Failure Experiments Performed between 2001 and 2011...

Noise levels from toys and recreational articles for children and teenagers.

PubMed

Hellstrom, P A; Dengerink, H A; Axelsson, A

1992-10-01

This study examined the noise level emitted by toys and recreational articles used by children and teenagers. The results indicate that many of the items tested emit sufficiently intense noise to be a source of noise induced hearing loss in school-age children. While the baby toys provided noise exposure within the limits of national regulations, they are most intense in a frequency range that corresponds to the resonance frequency of the external auditory canal of very young children. Hobby motors emit noise that may require protection depending upon the length of use. Fire-crackers and cap guns emit impulse noises that exceed even conservative standards for noise exposure.

Environmental variables and levels of exhaled carbon monoxide and carboxyhemoglobin in elderly people taking exercise.

PubMed

Salicio, Marcos Adriano; Mana, Viviane Aparecida Martins; Fett, Waléria Christiane Rezende; Gomes, Luciano Teixeira; Botelho, Clovis

2016-04-01

This article aims to analyze levels of exhaled carbon monoxide, carboxyhemoglobinand cardiopulmonary variables in old people practicing exercise in external environments, and correlate them with climate and pollution factors. Temporal ecological study with118 active elderly people in the city of Cuiabá, in the state of Mato Grosso, Brazil. Data were obtained on use of medication, smoking, anthropometric measurements, spirometry, peak flow, oxygen saturation, heart rate, exhaled carbon monoxide, carboxyhemoglobin, climate, number of farm fires and pollution. Correlations were found between on the one hand environmental temperature, relative humidity of the air and number of farmers' fires, and on the other hand levels of carbon monoxide exhaled and carboxyhemoglobin (p < 0.05).There was a correlation between heart rate and changes in environmental temperature, time of exposure to the sun and relative humidity (p < 0.05). In elderly people, environmental factors influence levels of exhaled carbon monoxide, carboxyhemoglobin and heart rate. There is thus a need for these to be monitored during exercise. The use of a carbon monoxide monitor to evaluate exposure to pollutants is suggested.

Bistability and up/down state alternations in inhibition-dominated randomly connected networks of LIF neurons.

PubMed

Tartaglia, Elisa M; Brunel, Nicolas

2017-09-20

Electrophysiological recordings in cortex in vivo have revealed a rich variety of dynamical regimes ranging from irregular asynchronous states to a diversity of synchronized states, depending on species, anesthesia, and external stimulation. The average population firing rate in these states is typically low. We study analytically and numerically a network of sparsely connected excitatory and inhibitory integrate-and-fire neurons in the inhibition-dominated, low firing rate regime. For sufficiently high values of the external input, the network exhibits an asynchronous low firing frequency state (L). Depending on synaptic time constants, we show that two scenarios may occur when external inputs are decreased: (1) the L state can destabilize through a Hopf bifucation as the external input is decreased, leading to synchronized oscillations spanning d δ to β frequencies; (2) the network can reach a bistable region, between the low firing frequency network state (L) and a quiescent one (Q). Adding an adaptation current to excitatory neurons leads to spontaneous alternations between L and Q states, similar to experimental observations on UP and DOWN states alternations.

Exposure to organophosphate flame retardants of hotel room attendants in Wuhan City, China.

PubMed

Tao, Yun; Shang, Yinzhu; Li, Jing; Feng, Jingwen; He, Zhenyu; Covaci, Adrian; Wang, Peng; Luo, Jing; Mao, Xiang; Shi, Bin; Hu, Liqin; Luo, Dan; Mei, Surong

2018-05-01

Indoor environments provide sources of exposure to organophosphate flame retardants (PFRs), which are artificially synthesized fire-protecting agents used as additives in interior products. As public spaces, hotels are required to meet stricter fire-precaution criteria. As such, room attendants may be exposed to higher levels of PFRs. Our goal was to characterize the exposure of hotel room attendants to PFRs by measuring metabolites in their urine and the corresponding parent PFRs in dust and hand-wipes collected from 27 hotels located in Wuhan City, China. The exposure of the attendants was found to be omnipresent: urinary metabolites of PFRs, such as DPHP (diphenyl phosphate), BDCIPP (bis(1,3-dichloro-2-propyl) phosphate), and DoCP (di-o-cresyl phosphate) & DpCP (di-p-cresyl phosphate) were detected with high frequency (87%, 79% and 87%, respectively). We observed that metabolites in post-shift urine were consistently present at higher levels than those in the first morning voids (p < 0.05 for BDCIPP and DPHP). Regarding external exposure, 10 PFRs were determined in both dust samples and hand-wipes, with TCIPP (tris(2-chloroisopropyl) phosphate) being the most abundant compound in both matrices. The levels of PFRs in hand-wipes and dust samples were not correlated. PFRs in dust and their corresponding urinary metabolites were not significantly correlated, while a moderate significant correlation of TDCIPP (tris(1,3-dichloro-2-propyl) phosphate) in hand-wipes and its urinary metabolite, BDCIPP, was observed in both morning void samples (p = 0.01) and post-shift urine (p = 0.002). Moreover, we found that participants from high-rise buildings (defined as > 7 stories) had significantly higher BDCIPP and DPHP concentrations than those from low-rise buildings. A possible reason is that high-rise buildings may use high-grade fireproof building materials to meet stricter fire restrictions. Overall, these results indicate that PFRs exposure in hotels is a contributor to the personal exposure of hotel room attendants. Copyright © 2018 Elsevier Ltd. All rights reserved.

Modeling heat and moisture transport in firefighter protective clothing during flash fire exposure

NASA Astrophysics Data System (ADS)

Chitrphiromsri, Patirop; Kuznetsov, Andrey V.

2005-01-01

In this paper, a model of heat and moisture transport in firefighter protective clothing during a flash fire exposure is presented. The aim of this study is to investigate the effect of coupled heat and moisture transport on the protective performance of the garment. Computational results show the distribution of temperature and moisture content in the fabric during the exposure to the flash fire as well as during the cool-down period. Moreover, the duration of the exposure during which the garment protects the firefighter from getting second and third degree burns from the flash fire exposure is numerically predicted. A complete model for the fire-fabric-air gap-skin system is presented.

A review of rapid and field-portable analytical techniques for the diagnosis of cyanide exposure.

PubMed

Jackson, Randy; Logue, Brian A

2017-04-01

Although commonly known as a highly toxic chemical, cyanide is also an essential reagent for many industrial processes in areas such as mining, electroplating and synthetic fiber production. The "heavy" use of cyanide in these industries, along with its necessary transportation, increases the possibility of human exposure. Another relatively common, but consistently overlooked, mode of cyanide exposure is inhalation of fire smoke. Both civilians and fire rescue personnel risk exposure during the unfortunate event of a structure fire. Additionally, fire rescue personnel risk long-term effects of habitual exposure throughout their careers in fire rescue. The relatively rapid onset of cyanide toxicity and the fact that cyanide exposure symptoms mimic other medical conditions necessitate a rapid, sensitive, portable, and accurate method for the diagnosis of cyanide exposure. This review focuses on the important issues concerning accurate point-of-care diagnosis of cyanide exposure and cyanide detection technologies that may allow a commercial cyanide exposure diagnostic to become a reality. Copyright © 2017 Elsevier B.V. All rights reserved.

Can bats sense smoke during deep torpor?

PubMed

Doty, Anna C; Currie, Shannon E; Stawski, Clare; Geiser, Fritz

2018-03-01

While torpor is a beneficial energy-saving strategy, it may incur costs if an animal is unable to respond appropriately to external stimuli, which is particularly true when it is necessary to escape from threats such as fire. We aimed to determine whether torpid bats, which are potentially threatened because they must fly to escape, can sense smoke and whether respiration rate (RR), heart rate (HR) and reaction time of torpid bats prior to and following smoke introduction is temperature-dependent. To test this we quantified RR and HR of captive Australian tree-roosting bats, Nyctophilus gouldi (n=5, ~10g), in steady-state torpor in response to short-term exposure to smoke from Eucalyptus spp. leaves between ambient temperatures (T a ) of 11 and 23°C. Bats at lower T a took significantly longer (28-fold) to respond to smoke, indicated by a cessation of episodic breathing and a rapid increase in RR. Bats at lower T a returned to torpor more swiftly following smoke exposure than bats at higher T a . Interestingly, bats at T a <15°C never returned to thermoconforming steady-state torpor prior to the end of the experimental day, whereas all bats at T a ≥15°C did, as indicated by apnoeic HR. This shows that although bats at lower T a took longer to respond, they appear to maintain vigilance and prevent deep torpor after the first smoke exposure, likely to enable fast escape. Our study reveals that bats can respond to smoke stimuli while in deep torpor. These results are particularly vital within the framework of fire management conducted at T a <15°C, as most management burns are undertaken during winter when bats will likely respond more slowly to fire cues such as smoke, delaying the time to escape from the fire. Copyright © 2017 Elsevier Inc. All rights reserved.

Ultrafine and respirable particle exposure during vehicle fire suppression

PubMed Central

Fent, Kenneth W.

2015-01-01

Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters’ potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator’s shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 107 particles per cm3, 170 mg m−3 respirable particle mass, 4700 μm2 cm−3 active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 104 particles per cm3, 0.36 mg m−3 respirable particle mass, 92 μm2 cm−3 active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 105 particles per cm3, 2.7 mg m−3 respirable particle mass, 320 μm2 cm−3 active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The wind direction and the relative position of the fire crew to the stationary burning vehicle played a primary role in fire crews’ potential for exposure. We recommend that firefighters wear self-contained breathing apparatus during all phases of the vehicle fire response to significantly reduce their potential for particulate, vapor, and gaseous exposures. PMID:26308547

Ultrafine and respirable particle exposure during vehicle fire suppression.

PubMed

Evans, Douglas E; Fent, Kenneth W

2015-10-01

Vehicle fires are a common occurrence, yet few studies have reported exposures associated with burning vehicles. This article presents an assessment of firefighters' potential for ultrafine and respirable particle exposure during vehicle fire suppression training. Fires were initiated within the engine compartment and passenger cabins of three salvaged vehicles, with subsequent water suppression by fire crews. Firefighter exposures were monitored with an array of direct reading particle and air quality instruments. A flexible metallic duct and blower drew contaminants to the instrument array, positioned at a safe distance from the burning vehicles, with the duct inlet positioned at the nozzle operator's shoulder. The instruments measured the particle number, active surface area, respirable particle mass, photoelectric response, aerodynamic particle size distributions, and air quality parameters. Although vehicle fires were suppressed quickly (<10 minutes), firefighters may be exposed to short duration, high particle concentration episodes during fire suppression, which are orders of magnitude greater than the ambient background concentration. A maximum transient particle concentration of 1.21 × 10(7) particles per cm(3), 170 mg m(-3) respirable particle mass, 4700 μm(2) cm(-3) active surface area and 1400 (arbitrary units) in photoelectric response were attained throughout the series of six fires. Expressed as fifteen minute time-weighted averages, engine compartment fires averaged 5.4 × 10(4) particles per cm(3), 0.36 mg m(-3) respirable particle mass, 92 μm(2) cm(-3) active particle surface area and 29 (arbitrary units) in photoelectric response. Similarly, passenger cabin fires averaged 2.04 × 10(5) particles per cm(3), 2.7 mg m(-3) respirable particle mass, 320 μm(2) cm(-3) active particle surface area, and 34 (arbitrary units) in photoelectric response. Passenger cabin fires were a greater potential source of exposure than engine compartment fires. The wind direction and the relative position of the fire crew to the stationary burning vehicle played a primary role in fire crews' potential for exposure. We recommend that firefighters wear self-contained breathing apparatus during all phases of the vehicle fire response to significantly reduce their potential for particulate, vapor, and gaseous exposures.

Animal exposure during burn tests

NASA Technical Reports Server (NTRS)

Gaume, J. G.

1976-01-01

An animal exposure test system has been designed and fabricated for the purpose of collecting physiological and environmental (temperature) data from animal subjects exposed to combustion gases in large scale fire tests. The AETS consists of an open wire mesh, two-compartment cage, one containing an exercise wheel for small rodents, and the other containing one rat instrumented externally for electrocardiogram and respiration. The ECG and respiration sensors are located in a belt placed around the torso of the subject, electrode wires forming an umbilical to a connector in the top of the compartment. A cable extends from the connector to the power supply and signal conditioning electronics. These are connected to a dual-beam oscilloscope for real time monitoring and a magnetic tape recorder having three or more channels. Endpoints observed are bradycardia, cardiac arrhythmias, changes in respiratory pattern, respiratory arrest and cardiac arrest. The ECG record also appears to be a good method of monitoring animal activity as indicated by an increase in EMG noise superimposed on the record during increased activity of the torso musculature. Examples of the recordings are presented and discussed as to their significance regarding toxicity of fire gases.

Fuselage ventilation due to wind flow about a postcrash aircraft

NASA Technical Reports Server (NTRS)

Stuart, J. W.

1980-01-01

Postcrash aircraft fuselage fire development, dependent on the internal and external fluid dynamics is discussed. The natural ventilation rate, a major factor in the internal flow patterns and fire development is reviewed. The flow about the fuselage as affected by the wind and external fire is studied. An analysis was performend which estimated the rates of ventilation produced by the wind for a limited idealized environmental configuration. The simulation utilizes the empirical pressure coefficient distribution of an infinite circular cylinder near a wall with its boundary later flow to represent the atmospheric boundary layer. The resulting maximum ventilation rate for two door size openings, with varying circumferential location in a common 10 mph wind was an order of magnitude greater than the forced ventilation specified in full scale fire testing. The parameter discussed are: (1) fuselage size and shape, (2) fuselage orientation and proximity to the ground, (3) fuselage-openings size and location, (4) wind speed and direction, and (5) induced flow of the external fire plume is recommended. The fire testing should be conducted to a maximum ventilation rate at least an order of magnitude greater than the inflight air conditioning rates.

Baseline measurements of smoke exposure among wildland firefighters.

PubMed

Reinhardt, Timothy E; Ottmar, Roger D

2004-09-01

Extensive measurements of smoke exposure among wildland firefighters are summarized, showing that firefighters can be exposed to significant levels of carbon monoxide and respiratory irritants, including formaldehyde, acrolein, and respirable particulate matter. Benzene was also measured and found to be well below permissible exposure limits, with the highest concentrations occurring among firefighters working with engines and torches burning petroleum-based fuel. Exposures to all pollutants were higher among firefighters at prescribed burns than at wildfires, while shift-average smoke exposures were lowest among firefighters who performed initial attack of wildfires in the early stages of the fires. Smoke exposure reaches its highest levels among firefighters maintaining fire within designated firelines and performing direct attack of spot fires that cross firelines. These events and the associated smoke exposures were positively correlated with increasing ambient wind speeds, which hamper fire management and carry the convective plume of the fire into firefighters' breathing zone. The pollutants measured in smoke were reasonably well-correlated with each other, enabling estimation of exposure to multiple pollutants in smoke from measurements of a single pollutant such as carbon monoxide.

Optimizing prescribed fire allocation for managing fire risk in central Catalonia.

PubMed

Alcasena, Fermín J; Ager, Alan A; Salis, Michele; Day, Michelle A; Vega-Garcia, Cristina

2018-04-15

We used spatial optimization to allocate and prioritize prescribed fire treatments in the fire-prone Bages County, central Catalonia (northeastern Spain). The goal of this study was to identify suitable strategic locations on forest lands for fuel treatments in order to: 1) disrupt major fire movements, 2) reduce ember emissions, and 3) reduce the likelihood of large fires burning into residential communities. We first modeled fire spread, hazard and exposure metrics under historical extreme fire weather conditions, including node influence grid for surface fire pathways, crown fraction burned and fire transmission to residential structures. Then, we performed an optimization analysis on individual planning areas to identify production possibility frontiers for addressing fire exposure and explore alternative prescribed fire treatment configurations. The results revealed strong trade-offs among different fire exposure metrics, showed treatment mosaics that optimize the allocation of prescribed fire, and identified specific opportunities to achieve multiple objectives. Our methods can contribute to improving the efficiency of prescribed fire treatment investments and wildfire management programs aimed at creating fire resilient ecosystems, facilitating safe and efficient fire suppression, and safeguarding rural communities from catastrophic wildfires. The analysis framework can be used to optimally allocate prescribed fire in other fire-prone areas within the Mediterranean region and elsewhere. Copyright © 2017 Elsevier B.V. All rights reserved.

Quantifying the influence of previously burned areas on suppression effectiveness and avoided exposure: A case study of the Las Conchas Fire

Treesearch

Matthew P. Thompson; Patrick Freeborn; Jon D. Rieck; Dave Calkin; Julie W. Gilbertson-Day; Mark A. Cochrane; Michael S. Hand

2016-01-01

We present a case study of the Las Conchas Fire (2011) to explore the role of previously burned areas (wildfires and prescribed fires) on suppression effectiveness and avoided exposure. Methodological innovations include characterisation of the joint dynamics of fire growth and suppression activities, development of a fire line effectiveness framework, and...

49 CFR 173.58 - Assignment of class and division for new explosives.

Code of Federal Regulations, 2011 CFR

2011-10-01

....4 explosives. In addition to the test prescribed in § 173.57 of this subchapter, a substance or... tests: Cap Sensitivity Test, Princess Incendiary Spark Test, DDT Test, and External Fire Test, each as... projection of fragments, occurs in the External Fire Test (Test Method 5(c), or (4) Ignition or explosion...

49 CFR 173.58 - Assignment of class and division for new explosives.

Code of Federal Regulations, 2012 CFR

2012-10-01

....4 explosives. In addition to the test prescribed in § 173.57 of this subchapter, a substance or... tests: Cap Sensitivity Test, Princess Incendiary Spark Test, DDT Test, and External Fire Test, each as... projection of fragments, occurs in the External Fire Test (Test Method 5(c), or (4) Ignition or explosion...

49 CFR 173.58 - Assignment of class and division for new explosives.

Code of Federal Regulations, 2014 CFR

2014-10-01

....4 explosives. In addition to the test prescribed in § 173.57 of this subchapter, a substance or... tests: Cap Sensitivity Test, Princess Incendiary Spark Test, DDT Test, and External Fire Test, each as... projection of fragments, occurs in the External Fire Test (Test Method 5(c), or (4) Ignition or explosion...

49 CFR 173.58 - Assignment of class and division for new explosives.

Code of Federal Regulations, 2010 CFR

2010-10-01

....4 explosives. In addition to the test prescribed in § 173.57 of this subchapter, a substance or... Sensitivity Test, Princess Incendiary Spark Test, DDT Test, and External Fire Test, each as described in the... fragments, occurs in the External Fire Test (Test Method 5(c), or (4) Ignition or explosion occurs in the...

49 CFR 173.58 - Assignment of class and division for new explosives.

Code of Federal Regulations, 2013 CFR

2013-10-01

....4 explosives. In addition to the test prescribed in § 173.57 of this subchapter, a substance or... tests: Cap Sensitivity Test, Princess Incendiary Spark Test, DDT Test, and External Fire Test, each as... projection of fragments, occurs in the External Fire Test (Test Method 5(c), or (4) Ignition or explosion...

Terminology and biology of fire scars in selected central hardwoods

Treesearch

Kevin T. Smith; Elaine Kennedy Sutherland

2001-01-01

Dendrochronological analysis of fire scars requires tree survival of fire exposure. Trees survive fire exposure by: (1) avoidance of injury through constitutive protection and (2) induced defense. Induced defenses include (a) compartmentalization processes that resist the spread of injury and infection and (b) closure processes that restore the continuity of the...

Occupational Exposure to Polycyclic Aromatic Hydrocarbon of Wildland Firefighters at Prescribed and Wildland Fires.

PubMed

Navarro, Kathleen M; Cisneros, Ricardo; Noth, Elizabeth M; Balmes, John R; Hammond, S Katharine

2017-06-06

Wildland firefighters suppressing wildland fires or conducting prescribed fires work long shifts during which they are exposed to high levels of wood smoke with no respiratory protection. Polycyclic aromatic hydrocarbons (PAHs) are hazardous air pollutants formed during incomplete combustion. Exposure to PAHs was measured for 21 wildland firefighters suppressing two wildland fires and 4 wildland firefighters conducting prescribed burns in California. Personal air samples were actively collected using XAD4-coated quartz fiber filters and XAD2 sorbent tubes. Samples were analyzed for 17 individual PAHs through extraction with dichloromethane and gas chromatograph-mass spectrometer analysis. Naphthalene, retene, and phenanthrene were consistently the highest measured PAHs. PAH concentrations were higher at wildland fires compared to prescribed fires and were highest for firefighters during job tasks that involve the most direct contact with smoke near an actively burning wildland fire. Although concentrations did not exceed current occupational exposure limits, wildland firefighters are exposed to PAHs not only on the fire line at wildland fires, but also while working prescribed burns and while off-duty. Characterization of occupational exposures from wildland firefighting is important to understand better any potential long-term health effects.

The influence of fire exposure on austenitic stainless steel for pressure vessel fitness-for-service assessment: Experimental research

NASA Astrophysics Data System (ADS)

Li, Bo; Shu, Wenhua; Zuo, Yantian

2017-04-01

The austenitic stainless steels are widely applied to pressure vessel manufacturing. The fire accident risk exists in almost all the industrial chemical plants. It is necessary to make safety evaluation on the chemical equipment including pressure vessels after fire. Therefore, the present research was conducted on the influences of fire exposure testing under different thermal conditions on the mechanical performance evolution of S30408 austenitic stainless steel for pressure vessel equipment. The metallurgical analysis described typical appearances in micro-structure observed in the material suffered by fire exposure. Moreover, the quantitative degradation of mechanical properties was investigated. The material thermal degradation mechanism and fitness-for-service assessment process of fire damage were further discussed.

The effect of low ceiling on the external combustion of the cabin fire

NASA Astrophysics Data System (ADS)

Su, Shichuan; Chen, Changyun; Wang, Liang; Wei, Chengyin; Cui, Haibing; Guo, Chengyu

2018-06-01

External combustion is a phenomenon where the flame flares out of the window and burns outside. Because of the particularity of the ship's cabin structure, there is a great danger in the external combustion. In this paper, the numerical calculation and analysis of three kinds of low ceiling ship cabin fire are analyzed based on the large eddy numerical simulation technique. Through the analysis of temperature, flue gas velocity, heat flux density and so on, the external combustion phenomenon of fire development is calculated. The results show that when external combustion occurs, the amount of fuel escaping decreases with the roof height. The temperature above the window increases with the height of the ceiling. The heat flux density in the external combustion flame is mainly provided by radiation, and convection is only a small part; In the plume area there is a time period, in this time period, the convective heat flux density is greater than the radiation heat flux, this time with the ceiling height increases. No matter which ceiling height, the external combustion will seriously damage the structure of the ship after a certain period of time. The velocity distribution of the three roof is similar, but with the height of the ceiling, the area size is also increasing.

Effect of wood smoke exposure on vascular function and thrombus formation in healthy fire fighters.

PubMed

Hunter, Amanda L; Unosson, Jon; Bosson, Jenny A; Langrish, Jeremy P; Pourazar, Jamshid; Raftis, Jennifer B; Miller, Mark R; Lucking, Andrew J; Boman, Christoffer; Nyström, Robin; Donaldson, Kenneth; Flapan, Andrew D; Shah, Anoop S V; Pung, Louis; Sadiktsis, Ioannis; Masala, Silvia; Westerholm, Roger; Sandström, Thomas; Blomberg, Anders; Newby, David E; Mills, Nicholas L

2014-12-09

Myocardial infarction is the leading cause of death in fire fighters and has been linked with exposure to air pollution and fire suppression duties. We therefore investigated the effects of wood smoke exposure on vascular vasomotor and fibrinolytic function, and thrombus formation in healthy fire fighters. In a double-blind randomized cross-over study, 16 healthy male fire fighters were exposed to wood smoke (~1 mg/m³ particulate matter concentration) or filtered air for one hour during intermittent exercise. Arterial pressure and stiffness were measured before and immediately after exposure, and forearm blood flow was measured during intra-brachial infusion of endothelium-dependent and -independent vasodilators 4-6 hours after exposure. Thrombus formation was assessed using the ex vivo Badimon chamber at 2 hours, and platelet activation was measured using flow cytometry for up to 24 hours after the exposure. Compared to filtered air, exposure to wood smoke increased blood carboxyhaemoglobin concentrations (1.3% versus 0.8%; P < 0.001), but had no effect on arterial pressure, augmentation index or pulse wave velocity (P > 0.05 for all). Whilst there was a dose-dependent increase in forearm blood flow with each vasodilator (P < 0.01 for all), there were no differences in blood flow responses to acetylcholine, sodium nitroprusside or verapamil between exposures (P > 0.05 for all). Following exposure to wood smoke, vasodilatation to bradykinin increased (P = 0.003), but there was no effect on bradykinin-induced tissue-plasminogen activator release, thrombus area or markers of platelet activation (P > 0.05 for all). Wood smoke exposure does not impair vascular vasomotor or fibrinolytic function, or increase thrombus formation in fire fighters. Acute cardiovascular events following fire suppression may be precipitated by exposure to other air pollutants or through other mechanisms, such as strenuous physical exertion and dehydration.

Characterization of exposure to byproducts from firing lead-free frangible ammunition in an enclosed, ventilated firing range.

PubMed

Grabinski, Christin M; Methner, Mark M; Jackson, Jerimiah M; Moore, Alexander L; Flory, Laura E; Tilly, Trevor; Hussain, Saber M; Ott, Darrin K

2017-06-01

U.S. Air Force small arms firing ranges began using copper-based, lead-free frangible ammunition in the early 2000s due to environmental and health concerns related to the use of lead-based ammunition. Exposure assessments at these firing ranges have routinely detected chemicals and metals in amounts much lower than their mass-based occupational exposure limits, yet, instructors report work-related health concerns including respiratory distress, nausea, and headache. The objective of this study at one firing range was to characterize the aerosol emissions produced by weapons during firing events and evaluate the ventilation system's effectiveness in controlling instructor exposure to these emissions. The ventilation system was assessed by measuring the range static air pressure differential and the air velocity at the firing line. Air flow patterns were near the firing line. Instructor exposure was sampled using a filter-based air sampling method for metals and a wearable, real-time ultrafine particle counter. Area air sampling was simultaneously performed to characterize the particle size distribution, morphology, and composition. In the instructor's breathing zone, the airborne mass concentration of copper was low (range = <1 µg/m 3 to 16 µg/m 3 ), yet the ultrafine (nanoscale) particle number concentration increased substantially during each firing event. Ultrafine particles contained some copper and were complex in morphology and composition. The ventilation assessment found that the average velocity across all shooting lanes was acceptable compared to the recommended guideline (20% of the ideal 0.38 m/s (75 ft/min). However, uniform, downrange airflow pattern requirements were not met. These results suggest that the mass-based occupational exposure limits, as applied to this environment, may not be protective enough to eliminate health complaints reported by instructors whose full-time job involves training personnel on weapons that fire lead-free frangible ammunition. Using an ultrafine particle counter appears to be an alternative method of assessing ventilation effectiveness in removing ultrafine particulate produced during firing events.

A COTS-MQS shipborne EO/IR imaging system

NASA Astrophysics Data System (ADS)

Hutchinson, Mark A.; Miller, John L.; Weaver, James

2005-05-01

The Sea Star SAFIRE is a commercially developed, off the shelf, military qualified system (COTS-MQS) consisting of a 640 by 480 InSb infrared imager, laser rangefinder and visible imager in a gyro-stabilized platform designed for shipborne applications. These applications include search and rescue, surveillance, fire control, fisheries patrol, harbor security, and own-vessel perimeter security and self protection. Particularly challenging considerations unique to shipborne systems include the demanding environment conditions, man-machine interfaces, and effects of atmospheric conditions on sensor performance. Shipborne environmental conditions requiring special attention include electromagnetic fields, as well as resistance to rain, ice and snow, shock, vibration, and salt. Features have been implemented to withstand exposure to water and high humidity; anti-ice/de-ice capability for exposure to snow and ice; wash/wipe of external windows; corrosion resistance for exposure to water and salt spray. A variety of system controller configurations provide man-machine interfaces suitable for operation on ships. EO sensor developments that address areas of haze penetration, glint, and scintillation will be presented.

Development of Subscale Fast Cookoff Test (PREPRINT)

DTIC Science & Technology

2006-09-21

The hazards classification procedures have been harmonized with both the UN Test and Criteria Manual for UN Series 1...aimed at the development of a sub-scale alternate test protocol to the external fire test currently required for final hazards classification (HC...external fire test currently required for final hazards classification (HC) of an ordnance system. The specific goal of this part of the task was

Development of Safety Assessment Code for Decommissioning of Nuclear Facilities

NASA Astrophysics Data System (ADS)

Shimada, Taro; Ohshima, Soichiro; Sukegawa, Takenori

A safety assessment code, DecDose, for decommissioning of nuclear facilities has been developed, based on the experiences of the decommissioning project of Japan Power Demonstration Reactor (JPDR) at Japan Atomic Energy Research Institute (currently JAEA). DecDose evaluates the annual exposure dose of the public and workers according to the progress of decommissioning, and also evaluates the public dose at accidental situations including fire and explosion. As for the public, both the internal and the external doses are calculated by considering inhalation, ingestion, direct radiation from radioactive aerosols and radioactive depositions, and skyshine radiation from waste containers. For external dose for workers, the dose rate from contaminated components and structures to be dismantled is calculated. Internal dose for workers is calculated by considering dismantling conditions, e.g. cutting speed, cutting length of the components and exhaust velocity. Estimation models for dose rate and staying time were verified by comparison with the actual external dose of workers which were acquired during JPDR decommissioning project. DecDose code is expected to contribute the safety assessment for decommissioning of nuclear facilities.

77 FR 58492 - Prohibitions Governing Fire

Federal Register 2010, 2011, 2012, 2013, 2014

2012-09-21

... DEPARTMENT OF AGRICULTURE Forest Service 36 CFR Part 261 RIN 0596-AD08 Prohibitions Governing Fire AGENCY: Forest Service, USDA. ACTION: Direct final rule. SUMMARY: The Forest Service is making purely... Fire. * * * * * (j) Operating or using any internal or external combustion engine without a spark...

External events analysis for the Savannah River Site K reactor

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

Brandyberry, M.D.; Wingo, H.E.

1990-01-01

The probabilistic external events analysis performed for the Savannah River Site K-reactor PRA considered many different events which are generally perceived to be external'' to the reactor and its systems, such as fires, floods, seismic events, and transportation accidents (as well as many others). Events which have been shown to be significant contributors to risk include seismic events, tornados, a crane failure scenario, fires and dam failures. The total contribution to the core melt frequency from external initiators has been found to be 2.2 {times} 10{sup {minus}4} per year, from which seismic events are the major contributor (1.2 {times} 10{supmore » {minus}4} per year). Fire initiated events contribute 1.4 {times} 10{sup {minus}7} per year, tornados 5.8 {times} 10{sup {minus}7} per year, dam failures 1.5 {times} 10{sup {minus}6} per year and the crane failure scenario less than 10{sup {minus}4} per year to the core melt frequency. 8 refs., 3 figs., 5 tabs.« less

Wildland smoke exposure values and exhaled breath indicators in firefighters.

PubMed

Miranda, Ana Isabel; Martins, Vera; Cascão, Pedro; Amorim, Jorge Humberto; Valente, Joana; Borrego, Carlos; Ferreira, António Jorge; Cordeiro, Carlos Robalo; Viegas, Domingos Xavier; Ottmar, Roger

2012-01-01

Smoke from forest fires contains significant amounts of gaseous and particulate pollutants. Firefighters exposed to wildland fire smoke can suffer from several acute and chronic adverse health effects. Consequently, exposure data are of vital importance for the establishment of cause/effect relationships between exposure to smoke and firefighter health effects. The aims of this study were to (1) characterize the relationship between wildland smoke exposure and medical parameters and (2) identify health effects pertinent to wildland forest fire smoke exposure. In this study, firefighter exposure levels of carbon monoxide (CO), nitrogen dioxide (NO₂), and volatile organic compounds (VOC) were measured in wildfires during three fire seasons in Portugal. Personal monitoring devices were used to measure exposure. Firefighters were also tested for exhaled nitric oxide (eNO) and CO before and after their firefighting activities. Data indicated that exposure levels during firefighting activities were beyond limits recommended by the Occupational Exposure Standard (OES) values. Medical tests conducted on the firefighters also indicated a considerable effect on measured medical parameters, with a significant increase in CO and decrease in NO in exhaled air of majority of the firefighters.

Motor unit recruitment and firing rate in medial gastrocnemius muscles during external perturbations in standing in humans.

PubMed

Pollock, C L; Ivanova, T D; Hunt, M A; Garland, S J

2014-10-01

There is limited investigation of the interaction between motor unit recruitment and rate coding for modulating force during standing or responding to external perturbations. Fifty-seven motor units were recorded from the medial gastrocnemius muscle with intramuscular electrodes in response to external perturbations in standing. Anteriorly directed perturbations were generated by applying loads in 0.45-kg increments at the pelvis every 25-40 s until 2.25 kg was maintained. Motor unit firing rate was calculated for the initial recruitment load and all subsequent loads during two epochs: 1) dynamic response to perturbation directly following each load drop and 2) maintenance of steady state between perturbations. Joint kinematics and surface electromyography (EMG) from lower extremities and force platform measurements were assessed. Application of the external loads resulted in a significant forward progression of the anterior-posterior center of pressure (AP COP) that was accompanied by modest changes in joint angles (<3°). Surface EMG increased more in medial gastrocnemius than in the other recorded muscles. At initial recruitment, motor unit firing rate immediately after the load drop was significantly lower than during subsequent load drops or during the steady state at the same load. There was a modest increase in motor unit firing rate immediately after the load drop on subsequent load drops associated with regaining balance. There was no effect of maintaining balance with increased load and forward progression of the AP COP on steady-state motor unit firing rate. The medial gastrocnemius utilized primarily motor unit recruitment to achieve the increased levels of activation necessary to maintain standing in the presence of external loads. Copyright © 2014 the American Physiological Society.

Effect of a long-term fire retardant (Fire Trol 934) on the germination of nine Mediterranean-type shrub species.

PubMed

Cruz, Alberto; Serrano, Marián; Navarro, Esther; Luna, Belén; Moreno, José M

2005-12-01

Fire Trol 934 is a long-term fire retardant commonly used in fire prevention and extinction. Our objective was to determine the effect of this chemical on seed germination of nine plant species from Mediterranean-type shrublands, where these chemicals are potentially used. Seeds were exposed to five different Fire Trol concentrations, (0 (control) to 10%, on a log scale) and monitored in a germination chamber for nine weeks. Seeds from four Cistus species were subjected to an additional heat treatment that simulated thermal scarification caused by fire. Retardant exposure caused a significant decrease in total germination in all species, and exposure to the highest Fire Trol concentration (10%) resulted in complete inhibition of germination. However, the sensitivity to Fire Trol varied across species and this differential species sensitivity may potentially lead to different impacts in the soil seed banks depending on whether sites are burned or unburned. Exposure to Fire Trol 934 may affect recruitment of shrubland species particularly during dry autumns, due to limited leaching of these chemicals from the soil surface. Consequently, its use should be avoided in sites where particularly sensitive plant species are present. Copyright (c) 2005 Wiley Periodicals, Inc.

Review of the health effects of wildland fire smoke on wildland firefighters and the public.

PubMed

Adetona, Olorunfemi; Reinhardt, Timothy E; Domitrovich, Joe; Broyles, George; Adetona, Anna M; Kleinman, Michael T; Ottmar, Roger D; Naeher, Luke P

2016-01-01

Each year, the general public and wildland firefighters in the US are exposed to smoke from wildland fires. As part of an effort to characterize health risks of breathing this smoke, a review of the literature was conducted using five major databases, including PubMed and MEDLINE Web of Knowledge, to identify smoke components that present the highest hazard potential, the mechanisms of toxicity, review epidemiological studies for health effects and identify the current gap in knowledge on the health impacts of wildland fire smoke exposure. Respiratory events measured in time series studies as incidences of disease-caused mortality, hospital admissions, emergency room visits and symptoms in asthma and chronic obstructive pulmonary disease patients are the health effects that are most commonly associated with community level exposure to wildland fire smoke. A few recent studies have also determined associations between acute wildland fire smoke exposure and cardiovascular health end-points. These cardiopulmonary effects were mostly observed in association with ambient air concentrations of fine particulate matter (PM2.5). However, research on the health effects of this mixture is currently limited. The health effects of acute exposures beyond susceptible populations and the effects of chronic exposures experienced by the wildland firefighter are largely unknown. Longitudinal studies of wildland firefighters during and/or after the firefighting career could help elucidate some of the unknown health impacts of cumulative exposure to wildland fire smoke, establish occupational exposure limits and help determine the types of exposure controls that may be applicable to the occupation.

Airborne asbestos exposures associated with work on asbestos fire sleeve materials.

PubMed

Blake, Charles L; Harbison, Stephen C; Johnson, Giffe T; Harbison, Raymond D

2011-11-01

Asbestos-containing fire sleeves have been used as a fire protection measure for aircraft fluid hoses. This investigation was conducted to determine the level of airborne asbestos fiber exposure experienced by mechanics who work with fire sleeve protected hoses. Duplicate testing was performed inside a small, enclosed workroom during the fabrication of hose assemblies. Personal air samples taken during this work showed detectable, but low airborne asbestos fiber exposures. Analysis of personal samples (n=9) using phrase contract microscopy (PCM) indicated task duration airborne fiber concentrations ranging from 0.017 to 0.063 fibers per milliliter (f/ml) for sampling durations of 167-198 min, and 0.022-0.14 f/ml for 30 min samples. Airborne chrysotile fibers were detected for four of these nine personal samples, and the resulting asbestos adjusted airborne fiber concentrations ranged from 0.014 to 0.025 f/ml. These results indicate that work with asbestos fire sleeve and fire sleeve protected hose assemblies, does not produce regulatory noncompliant levels of asbestos exposure for persons who handle, cut and fit these asbestos-containing materials. Copyright © 2011 Elsevier Inc. All rights reserved.

Lead exposures and biological responses in military weapons systems: Aerosol characteristics and acute lead effects among US Army artillerymen: Final report

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

Bhattacharyya, M.H.; Stebbings, J.H.; Peterson, D.P.

1993-03-01

This study was to determine the concentration and chemical nature of lead (Pb) aerosols produced during the firing of artillery and to determine the exposures and biological responses of crew members exposed to lead aerosols during such firing. The concentrations of lead-containing aerosols at crew positions depended on wind conditions, with higher concentrations when firing into a head wind. Aerosol concentrations were highest in the muzzle blast zone. Concentrations of lead in the blood of crew members rose during the first 12 days of exposure to elevated airborne lead concentrations and then leveled off. There was no rapid decrease inmore » blood lead concentrations after completion of firing. Small decreases in hematocrit and small increases in free erythrocyte porphyrin were correlated with increasing exposure to airborne lead. These changes were reversed by seven weeks after firing. Changes in nerve conduction velocity had borderline statistical significance to airborne lead exposure. In measuring nerve conduction velocity, differences in skin temperature must be taken into account.« less

Radiological Impact Associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) from Coal-Fired Power Plants Emissions - 13436

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

Dinis, Maria de Lurdes; Fiuza, Antonio; Soeiro de Carvalho, Jose

2013-07-01

Certain materials used and produced in a wide range of non-nuclear industries contain enhanced activity concentrations of natural radionuclides. In particular, electricity production from coal is one of the major sources of increased human exposure to naturally occurring radioactive materials. A methodology was developed to assess the radiological impact due to natural radiation background. The developed research was applied to a specific case study, the Sines coal-fired power plant, located in the southwest coastline of Portugal. Gamma radiation measurements were carried out with two different instruments: a sodium iodide scintillation detector counter (SPP2 NF, Saphymo) and a gamma ray spectrometermore » with energy discrimination (Falcon 5000, Canberra). Two circular survey areas were defined within 20 km of the power plant. Forty relevant measurements points were established within the sampling area: 15 urban and 25 suburban locations. Additionally, ten more measurements points were defined, mostly at the 20-km area. The registered gamma radiation varies from 20 to 98.33 counts per seconds (c.p.s.) corresponding to an external gamma exposure rate variable between 87.70 and 431.19 nGy/h. The highest values were measured at locations near the power plant and those located in an area within the 6 and 20 km from the stacks. In situ gamma radiation measurements with energy discrimination identified natural emitting nuclides as well as their decay products (Pb-212, Pb-2142, Ra-226, Th-232, Ac-228, Th-234, Pa-234, U- 235, etc.). According to the results, an influence from the stacks emissions has been identified both qualitatively and quantitatively. The developed methodology accomplished the lack of data in what concerns to radiation rate in the vicinity of Sines coal-fired power plant and consequently the resulting exposure to the nearby population. (authors)« less

Comparison of Available Technologies for Fire Spots Detection via Linear Heat Detector

NASA Astrophysics Data System (ADS)

Miksa, František; Nemlaha, Eduard

2016-12-01

It is very demanding to detect fire spots under difficult conditions with high occurrence of interfering external factors such as large distances, airflow difficultly, high dustiness, high humidity, etc. Spot fire sensors do not meet the requirements due to the aforementioned conditions as well as large distances. Therefore, the detection of a fire spot via linear heat sensing cables is utilized.

Analysis of the Influence of Construction Insulation Systems on Public Safety in China

PubMed Central

Zhang, Guowei; Zhu, Guoqing; Zhao, Guoxiang

2016-01-01

With the Government of China’s proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies. PMID:27589774

Analysis of the Influence of Construction Insulation Systems on Public Safety in China.

PubMed

Zhang, Guowei; Zhu, Guoqing; Zhao, Guoxiang

2016-08-30

With the Government of China's proposed Energy Efficiency Regulations (GB40411-2007), the implementation of external insulation systems will be mandatory in China. The frequent external insulation system fires cause huge numbers of casualties and extensive property damage and have rapidly become a new hot issue in construction evacuation safety in China. This study attempts to reconstruct an actual fire scene and propose a quantitative risk assessment method for upward insulation system fires using thermal analysis tests and large eddy simulations (using the Fire Dynamics Simulator (FDS) software). Firstly, the pyrolysis and combustion characteristics of Extruded polystyrene board (XPS panel), such as ignition temperature, combustion heat, limiting oxygen index, thermogravimetric analysis and thermal radiation analysis were studied experimentally. Based on these experimental data, large eddy simulation was then applied to reconstruct insulation system fires. The results show that upward insulation system fires could be accurately reconstructed by using thermal analysis test and large eddy simulation. The spread of insulation material system fires in the vertical direction is faster than that in the horizontal direction. Moreover, we also find that there is a possibility of flashover in enclosures caused by insulation system fires as the smoke temperature exceeds 600 °C. The simulation methods and experimental results obtained in this paper could provide valuable references for fire evacuation, hazard assessment and fire resistant construction design studies.

Assessment of urinary metals following exposure to a large vegetative fire, New Mexico, 2000.

PubMed

Wolfe, Mitchell I; Mott, Joshua A; Voorhees, Ronald E; Sewell, C Mack; Paschal, Dan; Wood, Charles M; McKinney, Patrick E; Redd, Stephen

2004-03-01

In May 2000, a vegetative fire burned 47,000 acres in northern New Mexico, including 7500 acres of land administered by the Los Alamos National Laboratory. We evaluated potential human exposures from the fire. We surveyed two populations (firefighters and the general population) in four cities for urine heavy metal concentrations. Reference concentrations were based on the Third National Health and Nutrition Examination Survey (NHANES III). Multivariate linear regression assessed the association of urinary metal concentrations with smoke exposure. We also performed isotopic analysis of uranium and cesium on a subset of specimens. A total of 92 firefighters and 135 nonfirefighters participated. In both populations, urinary nickel, cesium, chromium, and uranium concentrations were greater than expected compared with NHANES III reference values. No values required immediate medical follow-up. Regression analysis demonstrated that for National Guard members, arsenic and cadmium levels were significantly related to smoke exposure, and for firefighters, cesium and arsenic levels were significantly related to exposure; however, only for cesium in National Guard members was this association in the positive direction. Isotopic analysis demonstrated that the cesium and uranium were naturally occurring. Some people had spot urine metal concentrations above nationally derived reference values, and values for some metals were associated with smoke exposure. These associations had little public health or clinical importance. Studies of exposures resulting from vegetative fires are difficult, and careful consideration should be given to the technical and communication processes at the outset of a fire exposure investigation. Recommendations for future investigations include testing as soon as possible during or after a fire, and early clinical consultation with a medical toxicologist.

Exposure assessment through realistic laboratory simulation of a soccer stadium fire.

PubMed

van Belle, N J C; van Putten, E M; de Groot, A C; Meeussen, V J A; Banus, S

2010-10-01

On Sunday April 13, 2008 a fire broke out on a grandstand in the Euroborg soccer stadium in Groningen The Netherlands. The polyamide chairs on the grandstand were set on fire and supporters were exposed to the emitted smoke which induced mild health effects. The Dutch government was concerned about potential health risks that such fires could have to exposed fans. Especially the exposure to toxic fumes was considered a risk because prior research has proven that large amounts of chemical compounds are emitted during the burning of chemical substances such as polyamide. Among these emitted compounds are HCN, CO, NO(x), NH(3) and volatile organic compounds. To study if supporters were exposed to hazardous chemical compounds we designed a laboratory controlled replica of a part of the grandstand of the Euroborg stadium to perform fire-experiments. This simulation of the fire under controlled circumstances proved that a wide variety of chemicals were emitted. Especially the emission of CO and NO(x) were high, but also the emission of formaldehyde might be toxicologically relevant. The emission of HCN and NH(3) were less than expected. Exposure assessment suggests that the exposure to NO(x) is the main health risk for the supporters that were present at the Euroborg fire. Copyright © 2010 Elsevier Ltd. All rights reserved.

A study on fire spreading model for the safety distance between the neighborhood occupancies and historical buildings in Taiwan

NASA Astrophysics Data System (ADS)

Chen, C. H.; Chien, S. W.; Ho, M. C.

2015-08-01

Cultural heritages and historical buildings are vulnerable against severe threats from fire. Since the 1970s, ten fire-spread events involving historic buildings have occurred in Taiwan, affecting a total of 132 nearby buildings. Developed under the influence of traditional Taiwanese culture, historic buildings in Taiwan are often built using non-fire resistant brick-wood structure and located in proximity to residential occupancies. Fire outbreak in these types of neighborhood will lead to severe damage of antiquities, leaving only unrecoverable historical imagery. This study is aimed to investigate the minimal safety distance required between a historical building and its surroundings in order to reduce the risk of external fire. This study is based on literature analysis and the fire spread model using a Fire Dynamics Simulator. The selected target is Jingmei Temple in Taipei City. This study explored local geography to identify patterns behind historical buildings distribution. In the past, risk reduction engineering for cultural heritages and historical buildings focused mainly on fire equipment and the available personnel with emergency response ability, and little attention was given to external fire risks and the affected damage. Through discussions on the required safety distance, this research provides guidelines for the following items: management of neighborhoods with historical buildings and consultation between the protection of cultural heritages and disaster prevention, reducing the frequency and extent of fire damages, and preserving cultural resource.

Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia.

PubMed

Crippa, P; Castruccio, S; Archer-Nicholls, S; Lebron, G B; Kuwata, M; Thota, A; Sumin, S; Butt, E; Wiedinmyer, C; Spracklen, D V

2016-11-16

Vegetation and peatland fires cause poor air quality and thousands of premature deaths across densely populated regions in Equatorial Asia. Strong El-Niño and positive Indian Ocean Dipole conditions are associated with an increase in the frequency and intensity of wildfires in Indonesia and Borneo, enhancing population exposure to hazardous concentrations of smoke and air pollutants. Here we investigate the impact on air quality and population exposure of wildfires in Equatorial Asia during Fall 2015, which were the largest over the past two decades. We performed high-resolution simulations using the Weather Research and Forecasting model with Chemistry based on a new fire emission product. The model captures the spatio-temporal variability of extreme pollution episodes relative to space- and ground-based observations and allows for identification of pollution sources and transport over Equatorial Asia. We calculate that high particulate matter concentrations from fires during Fall 2015 were responsible for persistent exposure of 69 million people to unhealthy air quality conditions. Short-term exposure to this pollution may have caused 11,880 (6,153-17,270) excess mortalities. Results from this research provide decision-relevant information to policy makers regarding the impact of land use changes and human driven deforestation on fire frequency and population exposure to degraded air quality.

Population exposure to hazardous air quality due to the 2015 fires in Equatorial Asia

PubMed Central

Crippa, P.; Castruccio, S.; Archer-Nicholls, S.; Lebron, G. B.; Kuwata, M.; Thota, A.; Sumin, S.; Butt, E.; Wiedinmyer, C.; Spracklen, D. V.

2016-01-01

Vegetation and peatland fires cause poor air quality and thousands of premature deaths across densely populated regions in Equatorial Asia. Strong El-Niño and positive Indian Ocean Dipole conditions are associated with an increase in the frequency and intensity of wildfires in Indonesia and Borneo, enhancing population exposure to hazardous concentrations of smoke and air pollutants. Here we investigate the impact on air quality and population exposure of wildfires in Equatorial Asia during Fall 2015, which were the largest over the past two decades. We performed high-resolution simulations using the Weather Research and Forecasting model with Chemistry based on a new fire emission product. The model captures the spatio-temporal variability of extreme pollution episodes relative to space- and ground-based observations and allows for identification of pollution sources and transport over Equatorial Asia. We calculate that high particulate matter concentrations from fires during Fall 2015 were responsible for persistent exposure of 69 million people to unhealthy air quality conditions. Short-term exposure to this pollution may have caused 11,880 (6,153–17,270) excess mortalities. Results from this research provide decision-relevant information to policy makers regarding the impact of land use changes and human driven deforestation on fire frequency and population exposure to degraded air quality. PMID:27848989

Prevalence of hydrogen cyanide and carboxyhaemoglobin in victims of smoke inhalation during enclosed-space fires: a combined toxicological risk.

PubMed

Grabowska, Teresa; Skowronek, Rafał; Nowicka, Joanna; Sybirska, Halina

2012-09-01

Hydrogen cyanide (HCN) is one of the most toxic components of fire smoke, but insufficient attention is paid to its potential role as a cause of injury or death in victims (alive or dead) of enclosed-space fires. To analyse the prevalence of toxic HCN exposure in fire victims and factors that may influence its toxicity, particularly the co-presence of carbon monoxide (CO) and ethanol. Blood samples from fire victims and persons rescued from fires were analysed. A positive result for HCN (mean concentration 16.83 mg/l) was detected in blood samples from 169 of 285 fire-related deaths (59%). Ethanol was present in 91 (65%) of 139 samples with coincident presence of HCN and carboxyhaemoglobin (COHb). HCN (mean 4.0 mg/l) was also detected in 20 of 40 (50%) fire survivors. The high prevalence of coincident CO and HCN in enclosed-space, fire-related deaths should alert clinicians to suspect toxic HCN exposure in all persons rescued from fire with signs and symptoms of respiratory distress. Medical procedures in persons rescued from enclosed-space fires, especially in the pre-hospital setting, should be augmented to cover the possibility of toxic HCN exposure, particularly in individuals who do not respond to standard supportive therapy. Likewise, post-mortem investigations should routinely include assays for HCN when determining probable cause of death.

Application of wildfire simulation methods to assess wildfire exposure in a Mediterranean fire-prone area (Sardinia, Italy)

NASA Astrophysics Data System (ADS)

Salis, M.; Ager, A.; Arca, B.; Finney, M.; Bacciu, V. M.; Spano, D.; Duce, P.

2012-12-01

Spatial and temporal patterns of fire spread and behavior are dependent on interactions among climate, topography, vegetation and fire suppression efforts (Pyne et al. 1996; Viegas 2006; Falk et al. 2007). Humans also play a key role in determining frequency and spatial distribution of ignitions (Bar Massada et al, 2011), and thus influence fire regimes as well. The growing incidence of catastrophic wildfires has led to substantial losses for important ecological and human values within many areas of the Mediterranean basin (Moreno et al. 1998; Mouillot et al. 2005; Viegas et al. 2006a; Riaño et al. 2007). The growing fire risk issue has led to many new programs and policies of fuel management and risk mitigation by environmental and fire agencies. However, risk-based methodologies to help identify areas characterized by high potential losses and prioritize fuel management have been lacking for the region. Formal risk assessment requires the joint consideration of likelihood, intensity, and susceptibility, the product of which estimates the chance of a specific loss (Brillinger 2003; Society of Risk Analysis, 2006). Quantifying fire risk therefore requires estimates of a) the probability of a specific location burning at a specific intensity and location, and b) the resulting change in financial or ecological value (Finney 2005; Scott 2006). When large fires are the primary cause of damage, the application of this risk formulation requires modeling fire spread to capture landscape properties that affect burn probability. Recently, the incorporation of large fire spread into risk assessment systems has become feasible with the development of high performance fire simulation systems (Finney et al. 2011) that permit the simulation of hundreds of thousands of fires to generate fine scale maps of burn probability, flame length, and fire size, while considering the combined effects of weather, fuels, and topography (Finney 2002; Andrews et al. 2007; Ager and Finney 2009; Finney et al. 2009; Salis et al. 2012 accepted). In this work, we employed wildfire simulation methods to quantify wildfire exposure to human and ecological values for the island of Sardinia, Italy. The work was focused on the risk and exposure posed by large fires (e.g. 100 - 10,000 ha), and considers historical weather, ignition patterns and fuels. We simulated 100,000 fires using burn periods that replicated the historical size distribution on the Island, and an ignition probability grid derived from historic ignition data. We then examine spatial variation in three exposure components (burn probability, flame length, fire size) among important human and ecological values. The results allowed us to contract exposure among and within the various features examined, and highlighted the importance of human factors in shaping wildfire exposure in Sardinia. The work represents the first application of burn probability modeling in the Mediterranean region, and sets the stage for expanded work in the region to quantify risk from large fires

Lead Exposure in Military Outdoor Firing Ranges.

PubMed

Greenberg, Nili; Frimer, Ron; Meyer, Robert; Derazne, Estella; Chodick, Gabrial

2016-09-01

Several studies have reported significant airborne lead exposures during training at indoor firing ranges. Scarce attention has been given to airborne lead exposures in outdoor shooting ranges with automatic weapons. To assess the prevalence and magnitude of airborne and blood lead levels (BLL) among firing instructors and shooters in military outdoor ranges. Exposure assessment, for both trainees and instructors, included airborne and BLL during basic and advanced training at outdoor firing ranges. Personal airborne samples were collected in both day and night shooting during both training periods. During basic training, there is 95% likelihood that up to 25% of instructors and 99% likelihood that up to 5% of trainees might be exposed above the action level (AL) (25 μg/m(3)). During advanced training, there is 90% likelihood that 10% of instructors and 99% likelihood that up to 10% of trainees might be exposed above the AL. Military personnel participating in automatic weapon marksmanship training can be exposed to considerable levels of airborne lead during outdoor firing range training. As a result, the Israel Defense Force Medical Corp has classified firing range instructors as workers that require periodic medical examinations. Reprint & Copyright © 2016 Association of Military Surgeons of the U.S.

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation.

PubMed

Wu, Juan; Xu, Yong; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected.

Lévy noise improves the electrical activity in a neuron under electromagnetic radiation

PubMed Central

Wu, Juan; Ma, Jun

2017-01-01

As the fluctuations of the internal bioelectricity of nervous system is various and complex, the external electromagnetic radiation induced by magnet flux on membrane can be described by the non-Gaussian type distribution of Lévy noise. Thus, the electrical activities in an improved Hindmarsh-Rose model excited by the external electromagnetic radiation of Lévy noise are investigated and some interesting modes of the electrical activities are exhibited. The external electromagnetic radiation of Lévy noise leads to the mode transition of the electrical activities and spatial phase, such as from the rest state to the firing state, from the spiking state to the spiking state with more spikes, and from the spiking state to the bursting state. Then the time points of the firing state versus Lévy noise intensity are depicted. The increasing of Lévy noise intensity heightens the neuron firing. Also the stationary probability distribution functions of the membrane potential of the neuron induced by the external electromagnetic radiation of Lévy noise with different intensity, stability index and skewness papremeters are analyzed. Moreover, through the positive largest Lyapunov exponent, the parameter regions of chaotic electrical mode of the neuron induced by the external electromagnetic radiation of Lévy noise distribution are detected. PMID:28358824

Wildfire spread, hazard and exposure metric raster grids for central Catalonia.

PubMed

Alcasena, Fermín J; Ager, Alan A; Salis, Michele; Day, Michelle A; Vega-Garcia, Cristina

2018-04-01

We provide 40 m resolution wildfire spread, hazard and exposure metric raster grids for the 0.13 million ha fire-prone Bages County in central Catalonia (northeastern Spain) corresponding to node influence grid (NIG), crown fraction burned (CFB) and fire transmission to residential houses (TR). Fire spread and behavior data (NIG, CFB and fire perimeters) were generated with fire simulation modeling considering wildfire season extreme fire weather conditions (97 th percentile). Moreover, CFB was also generated for prescribed fire (Rx) mild weather conditions. The TR smoothed grid was obtained with a geospatial analysis considering large fire perimeters and individual residential structures located within the study area. We made these raster grids available to assist in the optimization of wildfire risk management plans within the study area and to help mitigate potential losses from catastrophic events.

Summaries of BFRL fire research in-house projects and grants, 1993

NASA Astrophysics Data System (ADS)

Jason, Nora H.

1993-09-01

The report describes the fire research projects performed in the Building and Fire Research Laboratory (BFRL) and under its extramural grants program during fiscal year 1993. The BFRL Fire Research Program has directed its efforts under three program thrusts. The in-house priority projects, grants, and externally-funded efforts thus form an integrated, focussed ensemble. The publication is organized along those lines: fire risk and hazard prediction - carbon monoxide prediction, turbulent combustion, soot, engineering analysis, fire hazard assessment, and large fires; fire safety of products and materials - materials combustion, furniture flammability, and wall and ceiling fires; and advanced technologies for fire sensing and control - fire detection and fire suppression. For the convenience of the reader, an alphabetical listing of all grants is contained in Part 2.0.

Post-fire analysis of construction materials

NASA Astrophysics Data System (ADS)

Schroeder, Robert Allen

The objective of this thesis is to determine and document the extent to which the fire damage in wood, concrete, and gypsum wallboard can be used to determine the time and heat flux exposure of the incipient stages of an uncontrolled fire event. A literature review outlines the state-of-the-art in three distinct areas: (1) Fire investigation; (2) The physical properties of wood, concrete, and gypsum wallboard, and (3) The fire response characteristics of those materials and their use in fire investigations. The results from quantitative experimental fire exposures of the subject materials are presented. The experiments were conducted under controlled conditions with the intent to develop standards for macroscopic and microscopic states of the materials for a given heat flux exposure and temperature. Standards and procedures are introduced for field sample collection, laboratory testing of the field samples, and interpretation of results. There are three major conclusions to be derived from this dissertation. The first two are that (1) wood and (2) concrete should not be viewed as reliable sources of information for a fire investigator to use for an analysis of how an actual fire ignited or spread. On the other hand the third major conclusion is that (3) gypsum wallboard can be considered a reliable source of information of fire behavior. The basis of each these conclusions is described in each of the chapters associated with each of the materials. One of the most important findings in this research is the use of X-ray diffraction to determine the maximum temperature reached by a sample of gypsum wallboard. Then by using the plots of isotherm progression it is possible to estimate the approximate length of exposure to a given heat flux. The use of gypsum-based post evidence is much more accurate than any available for wood or for concrete.

Effect of gap junctions on the firing patterns and synchrony for different external inputs in the striatal fast-spiking neuron network.

PubMed

Zhang, Mingming; Zhao, Zongya; He, Ping; Wang, Jue

2014-01-01

Gap junctions are the mechanism for striatal fast-spiking interneurons (FSIs) to interconnect with each other and play an important role in determining the physiological functioning of the FSIs. To investigate the effect of gap junctions on the firing activities and synchronization of the network for different external inputs, a simple network with least connections and a Newman-Watts small-world network were constructed. Our research shows that both properties of neural networks are related to the conductance of the gap junctions, as well as the frequency and correlation of the external inputs. The effect of gap junctions on the synchronization of network is different for inputs with different frequencies and correlations. The addition of gap junctions can promote the network synchrony in some conditions but suppress it in others, and they can inhibit the firing activities in most cases. Both the firing rate and synchronization of the network increase along with the increase of the electrical coupling strength for inputs with low frequency and high correlation. Thus, the network of coupled FSIs can act as a detector for synchronous synaptic input from cortex and thalamus.

Ignition and flame travel on realistic building and landscape objects in changing environments

Treesearch

Mark A. Dietenberger

2007-01-01

Effective mitigation of external fires on structures can be achieved flexibly, economically, and aesthetically by (1) preventing large-area ignition on structures from close proximity of burning vegetations and (2) stopping flame travel from firebrands landing on combustible building objects. In using bench-scale and mid-scale fire tests to obtain fire growth...

Development of model infectious disease protocols for fire and EMS personnel.

PubMed

Miller, Nancy L; Gudmestad, Tom; Eisenberg, Mickey S

2005-01-01

To develop model infectious disease exposure plans for emergency medical services agencies in King County, Washington. All fire departments in King County, Washington, were surveyed to determine their pathogen exposure policies. After these agencies were surveyed, model response plans were developed for both bloodborne and airborne pathogen exposure. Twenty-four of the 35 fire departments in King County submitted infectious disease exposure policies. There was diversity among the plans, and not all were deemed able to provide prophylaxis in a timely fashion. Based on this lack of uniformity among response plans, model response plans were developed for bloodborne and airborne infectious disease pathogens. Great variety was present throughout the exposure plans currently in use throughout King County, Washington. Model plans would likely universalize response to pathogen exposure and help to ensure prompt and appropriate postexposure prophylaxis.

Mortality due to Vegetation Fire-Originated PM2.5 Exposure in Europe-Assessment for the Years 2005 and 2008.

PubMed

Kollanus, Virpi; Prank, Marje; Gens, Alexandra; Soares, Joana; Vira, Julius; Kukkonen, Jaakko; Sofiev, Mikhail; Salonen, Raimo O; Lanki, Timo

2017-01-01

Vegetation fires can release substantial quantities of fine particles (PM2.5), which are harmful to health. The fire smoke may be transported over long distances and can cause adverse health effects over wide areas. We aimed to assess annual mortality attributable to short-term exposures to vegetation fire-originated PM2.5 in different regions of Europe. PM2.5 emissions from vegetation fires in Europe in 2005 and 2008 were evaluated based on Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data on fire radiative power. Atmospheric transport of the emissions was modeled using the System for Integrated modeLling of Atmospheric coMposition (SILAM) chemical transport model. Mortality impacts were estimated for 27 European countries based on a) modeled daily PM2.5 concentrations and b) population data, both presented in a 50 × 50 km2 spatial grid; c) an exposure-response function for short-term PM2.5 exposure and daily nonaccidental mortality; and d) country-level data for background mortality risk. In the 27 countries overall, an estimated 1,483 and 1,080 premature deaths were attributable to the vegetation fire-originated PM2.5 in 2005 and 2008, respectively. Estimated impacts were highest in southern and eastern Europe. However, all countries were affected by fire-originated PM2.5, and even the lower concentrations in western and northern Europe contributed substantially (~ 30%) to the overall estimate of attributable mortality. Our assessment suggests that air pollution caused by PM2.5 released from vegetation fires is a notable risk factor for public health in Europe. Moreover, the risk can be expected to increase in the future as climate change proceeds. This factor should be taken into consideration when evaluating the overall health and socioeconomic impacts of these fires. Citation: Kollanus V, Prank M, Gens A, Soares J, Vira J, Kukkonen J, Sofiev M, Salonen RO, Lanki T. 2017. Mortality due to vegetation fire-originated PM2.5 exposure in Europe-assessment for the years 2005 and 2008. Environ Health Perspect 125:30-37; http://dx.doi.org/10.1289/EHP194.

Irresistible ants: exposure to novel toxic prey increases consumption over multiple temporal scales.

PubMed

Herr, Mark W; Robbins, Travis R; Centi, Alan; Thawley, Christopher J; Langkilde, Tracy

2016-07-01

As species become increasingly exposed to novel challenges, it is critical to understand how evolutionary (i.e., generational) and plastic (i.e., within lifetime) responses work together to determine a species' fate or predict its distribution. The introduction of non-native species imposes novel pressures on the native species that they encounter. Understanding how native species exposed to toxic or distasteful invaders change their feeding behavior can provide insight into their ability to cope with these novel threats as well as broader questions about the evolution of this behavior. We demonstrated that native eastern fence lizards do not avoid consuming invasive fire ants following repeated exposure to this toxic prey. Rather fence lizards increased their consumption of these ants following exposure on three different temporal scales. Lizards ate more fire ants when they were exposed to this toxic prey over successive days. Lizards consumed more fire ants if they had been exposed to fire ants as juveniles 6 months earlier. Finally, lizards from populations exposed to fire ants over multiple generations consumed more fire ants than those from fire ant-free areas. These results suggest that the potentially lethal consumption of fire ants may carry benefits resulting in selection for this behavior, and learning that persists long after initial exposure. Future research on the response of native predators to venomous prey over multiple temporal scales will be valuable in determining the long-term effects of invasion by these novel threats.

Charring rate of wood exposed to a constant heat flux

Treesearch

R. H. White; H. C. Tran

1996-01-01

A critical factor in the fire endurance of a wood member is its rate of charring. Most available charring rate data have been obtained using the time-temperature curves of the standard fire resistance tests (ASTM E 119 and ISO 834) to define the fire exposure. The increased use of heat release calorimeters using exposures of constant heat flux levels has broadened the...

Analyzing wildfire exposure and source–sink relationships on a fire prone forest landscape

Treesearch

Alan A. Ager; Nicole M. Vaillant; Mark A. Finney; Haiganoush K. Preisler

2012-01-01

We used simulation modeling to analyze wildfire exposure to social and ecological values on a 0.6 million ha national forest in central Oregon, USA. We simulated 50,000 wildfires that replicated recent fire events in the area and generated detailed maps of burn probability (BP) and fire intensity distributions. We also recorded the ignition locations and size of each...

Caudate neuronal recording in freely behaving animals following acute and chronic dose response methylphenidate exposure

PubMed Central

Claussen, Catherine M; Dafny, Nachum

2016-01-01

The misuse and abuse of the psychostimulant, methylphenidate (MPD) the drug of choice in the treatment of attention deficit hyperactivity disorder (ADHD) has seen a sharp uprising in recent years among both youth and adults for its cognitive enhancing effects and for recreational purposes. This uprise in illicit use has lead to many questions concerning the long term consequences of MPD exposure. The objective of this study was to record animal behavior concomitantly with the caudate nucleus (CN) neuronal activity following acute and repetitive (chronic) dose response exposure to methylphenidate (MPD). A saline control and three MPD dose (0.6, 2.5, and 10.0 mg/kg) groups were used. Behaviorally, the same MPD dose in some animals following chronic MPD exposure elicited behavioral sensitization and other animals elicited behavioral tolerance. Based on this finding, the CN neuronal population recorded from animals expressing behavioral sensitization were also evaluated separately from CN neurons recorded from animals expressing behavioral tolerance to chronic MPD exposure, respectively. Significant differences in CN neuronal population responses between the behaviorally sensitized and the behaviorally tolerant animals was observed for the 2.5 and 10.0 mg/kg MPD exposed groups. For 2.5 mg/kg MPD, behaviorally sensitized animals responded by decreasing their firing rates while behaviorally tolerant animals showed mainly an increase in their firing rates. The CN neuronal responses recorded from the behaviorally sensitized animals following 10.0 mg/kg MPD responded by increasing their firing rates whereas the CN neuronal recordings from the behaviorally tolerant animals showed that approximately half decreased their firing rates in response to 10.0 mg/kg MPD exposure. The comparison of percentage change in neuronal firing rates showed that the behaviorally tolerant animals trended to exhibit increases in their neuronal firing rates at ED1 following initial MPD exposure and oppositely at ED10 MPD rechallenge. While the behaviorally sensitized animals in general increased in their percentage change of firing rats were observed following acute 10.0 mg/kg MPD and the behaviorally sensitized 10.0 mg/kg MPD animals and a robust increase in neuronal firing rates at ED1 and ED10 rechallenge. These results suggest the need to first individually analyze animal behavioral activity, and than to evaluate the neuronal responses to the drug based on the animals behavioral response to chronic MPD exposure. PMID:26101057

Best practices for interacting with the public about wildland fire: Key findings from interviews

Treesearch

Daniel Berkman

2012-01-01

Interviews were conducted with public information and line officers about wildland fire communications with the public. The goal of these interviews was to determine the best practices and most useful content and format for an annotated bibliography about external wildland fire communications, i.e., does the current literature reviewed address the issues of greatest...

Shotgun cartridge rock breaker

DOEpatents

Ruzzi, Peter L.; Morrell, Roger J.

1995-01-01

A rock breaker uses shotgun cartridges or other firearm ammunition as the explosive charge at the bottom of a drilled borehole. The breaker includes a heavy steel rod or bar, a gun with a firing chamber for the ammunition which screws onto the rod, a long firing pin running through a central passage in the rod, and a firing trigger mechanism at the external end of the bar which strikes the firing pin to fire the cartridge within the borehole. A tubular sleeve surround the main body of the rod and includes slits the end to allow it to expand. The rod has a conical taper at the internal end against which the end of the sleeve expands when the sleeve is forced along the rod toward the taper by a nut threaded onto the external end of the rod. As the sleeve end expands, it pushes against the borehole and holds the explosive gasses within, and also prevents the breaker from flying out of the borehole. The trigger mechanism includes a hammer with a slot and a hole for accepting a drawbar or drawpin which, when pulled by a long cord, allows the cartridge to be fired from a remote location.

Influence of fuels, weather and the built environment on the exposure of property to wildfire

USGS Publications Warehouse

Penman, Trent D.; Collins, Luke S.; Syphard, Alexandra D.; Keeley, Jon E.; Bradstock, Ross A.

2014-01-01

Wildfires can pose a significant risk to people and property. Billions of dollars are spent investing in fire management actions in an attempt to reduce the risk of loss. One of the key areas where money is spent is through fuel treatment – either fuel reduction (prescribed fire) or fuel removal (fuel breaks). Individual treatments can influence fire size and the maximum distance travelled from the ignition and presumably risk, but few studies have examined the landscape level effectiveness of these treatments. Here we use a Bayesian Network model to examine the relative influence of the built and natural environment, weather, fuel and fuel treatments in determining the risk posed from wildfire to the wildland-urban interface. Fire size and distance travelled was influenced most strongly by weather, with exposure to fires most sensitive to changes in the built environment and fire parameters. Natural environment variables and fuel load all had minor influences on fire size, distance travelled and exposure of assets. These results suggest that management of fuels provided minimal reductions in risk to assets and adequate planning of the changes in the built environment to cope with the expansion of human populations is going to be vital for managing risk from fire under future climates.

Influence of Fuels, Weather and the Built Environment on the Exposure of Property to Wildfire

PubMed Central

Penman, Trent D.; Collins, Luke; Syphard, Alexandra D.; Keeley, Jon E.; Bradstock, Ross A.

2014-01-01

Wildfires can pose a significant risk to people and property. Billions of dollars are spent investing in fire management actions in an attempt to reduce the risk of loss. One of the key areas where money is spent is through fuel treatment – either fuel reduction (prescribed fire) or fuel removal (fuel breaks). Individual treatments can influence fire size and the maximum distance travelled from the ignition and presumably risk, but few studies have examined the landscape level effectiveness of these treatments. Here we use a Bayesian Network model to examine the relative influence of the built and natural environment, weather, fuel and fuel treatments in determining the risk posed from wildfire to the wildland-urban interface. Fire size and distance travelled was influenced most strongly by weather, with exposure to fires most sensitive to changes in the built environment and fire parameters. Natural environment variables and fuel load all had minor influences on fire size, distance travelled and exposure of assets. These results suggest that management of fuels provided minimal reductions in risk to assets and adequate planning of the changes in the built environment to cope with the expansion of human populations is going to be vital for managing risk from fire under future climates. PMID:25360741

Clarifying the role of fire heat and daily temperature fluctuations as germination cues for Mediterranean Basin obligate seeders.

PubMed

Santana, Victor M; Baeza, M Jaime; Blanes, M Carmen

2013-01-01

This study aims to determine the role that both direct effects of fire and subsequent daily temperature fluctuations play in the seed bank dynamics of obligate seeders from the Mediterranean Basin. The short yet high soil temperatures experienced due to passage of fire are conflated with the lower, but longer, temperatures experienced by daily fluctuations which occur after removing vegetation. These germination cues are able to break seed dormancy, but it is difficult to assess their specific level of influence because they occur consecutively after summer fires, just before the flush of germination in the wet season (autumn). By applying experimental fires, seed treatments were imposed that combined fire exposure/non-fire exposure with exposure to microhabitats under a gradient of disturbance (i.e. gaps opened by fire, mechanical brushing and intact vegetation). The seeds used were representative of the main families of obligate seeders (Ulex parviflorus, Cistus albidus and Rosmarinus officinalis). Specifically, an assessment was made of (1) the proportion of seeds killed by fire, (2) seedling emergence under field conditions and (3) seeds which remained ungerminated in soil. For the three species studied, the factors that most influenced seedling emergence and seeds remaining ungerminated were microhabitats with higher temperature fluctuations after fire (gaps opened by fire and brushing treatments). The direct effect of fire decreased the seedling emergence of U. parviflorus and reduced the proportion of seeds of R. officinalis remaining ungerminated. The relevance of depleting vegetation (and subsequent daily temperature fluctuation in summer) suggests that studies focusing on lower temperature thresholds for breaking seed dormancy are required. This fact also supports the hypothesis that the seeding capacity in Mediterranean Basin obligate seeders may have evolved as a response to a wide range of disturbances, and not exclusively to fire.

Behavior of medial gastrocnemius motor units during postural reactions to external perturbations after stroke.

PubMed

Pollock, C L; Ivanova, T D; Hunt, M A; Garland, S J

2015-10-01

This study investigated the behavior of medial gastrocnemius (GM) motor units (MU) during external perturbations in standing in people with chronic stroke. GM MUs were recorded in standing while anteriorly-directed perturbations were introduced by applying loads of 1% body mass (BM) at the pelvis every 25-40s until 5% BM was maintained. Joint kinematics, surface electromyography (EMG), and force platform measurements were assessed. Although external loads caused a forward progression of the anterior-posterior centre of pressure (APCOP), people with stroke decreased APCOP velocity and centre of mass (COM) velocity immediately following the highest perturbations, thereby limiting movement velocity in response to perturbations. MU firing rate did not increase with loading but the GM EMG magnitude increased, reflecting MU recruitment. MU inter spike interval (ISI) during the dynamic response was negatively correlated with COM velocity and hip angular velocity. The GM utilized primarily MU recruitment to maintain standing during external perturbations. The lack of MU firing rate modulation occurred with a change in postural central set. However, the relationship of MU firing rate with kinematic variables suggests underlying long-loop responses may be somewhat intact after stroke. People with stroke demonstrate alterations in postural control strategies which may explain MU behavior with external perturbations. Copyright © 2014 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Behavior of Steel-Sheathed Shear Walls Subjected to Seismic and Fire Loads.

PubMed

Hoehler, Matthew S; Smith, Christopher M; Hutchinson, Tara C; Wang, Xiang; Meacham, Brian J; Kamath, Praveen

2017-07-01

A series of tests was conducted on six 2.7 m × 3.7 m shear wall specimens consisting of cold-formed steel framing sheathed on one side with sheet steel adhered to gypsum board and on the opposite side with plain gypsum board. The specimens were subjected to various sequences of simulated seismic shear deformation and fire exposure to study the influence of multi-hazard interactions on the lateral load resistance of the walls. The test program was designed to complement a parallel effort at the University of California, San Diego to investigate a six-story building subjected to earthquakes and fires. The test results reported here indicate that the fire exposure caused a shift in the failure mode of the walls from local buckling of the sheet steel in cases without fire exposure, to global buckling of the sheet steel with an accompanying 35 % reduction in lateral load capacity after the wall had been exposed to fire. This behavior appears to be predictable, which is encouraging from the standpoint of residual lateral load capacity under these severe multi-hazard actions.

The effects of nicotine exposure and PFC transection on the time-frequency distribution of VTA DA neurons' firing activities.

PubMed

Chen, Ting Y; Zhang, Die; Dragomir, Andrei; Akay, Yasemin; Akay, Metin

2011-05-01

We investigated the influence of nicotine exposure and prefrontal cortex (PFC) transections on ventral tegmental areas (VTA) dopamine (DA) neurons' firing activities using a time-frequency method based on the continuous wavelet transform (CWT). Extracellular single-unit neural activity was recorded from DA neurons in the VTA area of rats. One group had their PFC inputs to the VTA intact, while the other group had the inputs to VTA bilaterally transected immediate caudal to the PFC. We hypothesized that the systemic nicotine exposure will significantly change the energy distribution in the recorded neural activity. Additionally, we investigated whether the loss of inputs to the VTA caused by the PFC transection resulted in the cancellation of the nicotine' effect on the neurons' firing patterns. The time-frequency representations of VTA DA neurons firing activity were estimated from the reconstructed firing rate histogram. The energy contents were estimated from three frequency bands, which are known to encompass the significant modes of operation of DA neurons. Our results show that systemic nicotine exposure disrupts the energy distribution in PFC-intact rats. Particularly, there is a significant increase in energy contents of the 1-1.5 Hz frequency band. This corresponds to an observed increase in the firing rate of VTA DA neurons following nicotine exposure. Additionally, our results from PFC-transected rats show that there is no change in the energy distribution of the recordings after systemic nicotine exposure. These results indicate that the PFC plays an important role in affecting the activities of VTA DA neurons and that the CWT is a useful method for monitoring the changes in neural activity patterns in both time and frequency domains.

Lead exposure and birth outcomes in five communities in Shoshone County, Idaho.

PubMed

Berkowitz, Zahava; Price-Green, Patricia; Bove, Frank J; Kaye, Wendy E

2006-03-01

This study examined birth outcomes in five towns in Shoshone County, Idaho, where residents were exposed to high levels of lead in air emissions during a 6-month period after a fire had damaged the main baghouse (pollution-control device) of a local lead smelter plant in September 1973. We studied birth certificate data of 169,878 live singleton infants born to mothers who resided in Idaho at the time of delivery. The outcomes evaluated were preterm infants, small-for-gestational-age (SGA) infants, low birthweight among term infants (TLBW), and mean birthweight among term infants (TMBW). The study compared births in the five towns in Shoshone County (exposed group) to births in the rest of Idaho during three exposure periods: "pre-fire," January 1, 1970-August 31, 1973; "high exposure," September 1, 1973-December 31, 1974; and "post-fire," January 1, 1975-December 31, 1981. During the high-exposure period, the exposed group had an increased prevalence of TLBW (OR=2.4; 90% CI: 1.6-3.6) and SGA (OR=1.9; 90% CI: 1.3-2.8) compared with the rest of Idaho. During the pre- and post-fire periods, the ORs for TLBW were 0.8 and 1.3, respectively, and for SGA, 1.0, and 1.3, respectively. During the high-exposure period, TMBW for the exposed group was 71 g lower than in the comparison group. The TMBW in the exposed group was 8 g lower in the pre-fire period and 26 g lower in the post-fire period than in the comparison group. The study found no increased risk for preterm birth in the exposed group. Maternal exposures to airborne lead emissions appeared to be associated with increased risks for SGA, TLBW, and reduced TMBW.

Cardiovascular health effects following exposure of human volunteers during fire extinction exercises.

PubMed

Andersen, Maria Helena Guerra; Saber, Anne Thoustrup; Pedersen, Peter Bøgh; Loft, Steffen; Hansen, Åse Marie; Koponen, Ismo Kalevi; Pedersen, Julie Elbæk; Ebbehøj, Niels; Nørskov, Eva-Carina; Clausen, Per Axel; Garde, Anne Helene; Vogel, Ulla; Møller, Peter

2017-09-06

Firefighters have increased risk of cardiovascular disease and of sudden death from coronary heart disease on duty while suppressing fires. This study investigated the effect of firefighting activities, using appropriate personal protective equipment (PPE), on biomarkers of cardiovascular effects in young conscripts training to become firefighters. Healthy conscripts (n = 43) who participated in a rescue educational course for firefighting were enrolled in the study. The exposure period consisted of a three-day training course where the conscripts participated in various firefighting exercises in a constructed firehouse and flashover container. The subjects were instructed to extinguish fires of either wood or wood with electrical cords and mattresses. The exposure to particulate matter (PM) was assessed at various locations and personal exposure was assessed by portable PM samplers and urinary excretion of 1-hydroxypyrene. Cardiovascular measurements included microvascular function and heart rate variability (HRV). The subjects were primarily exposed to PM in bystander positions, whereas self-contained breathing apparatus effectively abolished pulmonary exposure. Firefighting training was associated with elevated urinary excretion of 1-hydroxypyrene (105%, 95% CI: 52; 157%), increased body temperature, decreased microvascular function (-18%, 95% CI: -26; -9%) and altered HRV. There was no difference in cardiovascular measurements for the two types of fires. Observations from this fire extinction training show that PM exposure mainly occurs in situations where firefighters removed the self-contained breathing apparatus. Altered cardiovascular disease endpoints after the firefighting exercise period were most likely due to complex effects from PM exposure, physical exhaustion and increased core body temperature.

Factors and processes causing accelerated decomposition in human cadavers - An overview.

PubMed

Zhou, Chong; Byard, Roger W

2011-01-01

Artefactually enhanced putrefactive and autolytic changes may be misinterpreted as indicating a prolonged postmortem interval and throw doubt on the veracity of witness statements. Review of files from Forensic Science SA and the literature revealed a number of external and internal factors that may be responsible for accelerating these processes. Exogenous factors included exposure to elevated environmental temperatures, both outdoors and indoors, exacerbated by increased humidity or fires. Situations indoor involved exposure to central heating, hot water, saunas and electric blankets. Deaths within motor vehicles were also characterized by enhanced decomposition. Failure to quickly or adequately refrigerate bodies may also lead to early decomposition. Endogenous factors included fever, infections, illicit and prescription drugs, obesity and insulin-dependent diabetes mellitus. When these factors or conditions are identified at autopsy less significance should, therefore, be attached to changes of decomposition as markers of time since death. Copyright © 2010 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Examination of Aircraft Interior Emergency Lighting in a Postcrash Fire Environment.

DTIC Science & Technology

1982-06-01

levels under realistic external fuel-fire conditions; (3) to compare black fuel-fire smoke with an enert white screen fog (references I and 2); (4... black smoke condition" at 52 seconds after the fuel fire was ignited and zero visibility a the 60-inch level at 120 seconds. Because it was closer to the...suitable stand was fabricated for each sign and the holes designed for aircraft mounting were utilized for securing the light to the stand. Two 28 AVG

Fire research publications, 1983

NASA Astrophysics Data System (ADS)

Jason, N. H.

1984-04-01

Approximately 130 articles are cited addressing topics in fire fighting and prevention, combustion physics, and fire related hazards. Only publications prepared by members of the Center for Fire Research (CFR), by other National Bureau of Standards (NBS) personnel for CFR, or by external laboratories under contract or grant from the CFR are cited. For documents that are available for purchase from either the Government Printing Office (GPO) or the National Technical Information Service (NTIS), the specific order number has been included in the citation.

The Future of wildland fire management in a world of rapid change and great uncertainty: Overview of a futures research project

Treesearch

David N. Bengston; Robert L. Olson; Leif A. DeVaney

2012-01-01

Past efforts to examine the future of wildland fire management have relied heavily on expertise from within the wildfire community. But changes in seemingly unrelated external factors - outside of the world of wildfire and fire management - can have unexpected and profound effects. This paper describes an ongoing sh1dy of the...

External human factors in incident management team decisionmaking and their effect on large fire suppression expenditures

Treesearch

Janie Canton-Tompson; Krista M. Gebert; Brooke Thompson; Greg Jones; David Calkin; Geoff Donovan

2008-01-01

Large wildland fires are complex, costly events influenced by a vast array of physical, climatic, and social factors. Changing climate, fuel buildup due to past suppression, and increasing populations in the wildland-urban interface have all been blamed for the extreme fire seasons and rising suppression expenditures of recent years. With each high-cost year comes a...

14 CFR 125.173 - Fire detectors.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 14 Aeronautics and Space 3 2014-01-01 2014-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may be...

14 CFR 125.173 - Fire detectors.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 14 Aeronautics and Space 3 2010-01-01 2010-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may be...

14 CFR 125.173 - Fire detectors.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 3 2013-01-01 2013-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may be...

14 CFR 125.173 - Fire detectors.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 14 Aeronautics and Space 3 2011-01-01 2011-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may be...

14 CFR 125.173 - Fire detectors.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 14 Aeronautics and Space 3 2012-01-01 2012-01-01 false Fire detectors. 125.173 Section 125.173....173 Fire detectors. Fire detectors must be made and installed in a manner that assures their ability... subjected. Fire detectors must be unaffected by exposure to fumes, oil, water, or other fluids that may be...

Firefighter noise exposure during training activities and general equipment use.

PubMed

Root, Kyle S; Schwennker, Catherine; Autenrieth, Daniel; Sandfort, Delvin R; Lipsey, Tiffany; Brazile, William J

2013-01-01

Multiple noise measurements were taken on 6 types of fire station equipment and 15 types of emergency response vehicle-related equipment used by firefighters during routine and emergency operations at 10 fire stations. Five of the six types of fire station equipment, when measured at a distance of one meter and ear level, emitted noise equal to or greater than 85 dBA, including lawn maintenance equipment, snow blowers, compressors, and emergency alarms. Thirteen of 15 types of equipment located on the fire engines emitted noise levels equal to or greater than 85 dBA, including fans, saws, alarms, and extrication equipment. In addition, noise measurements were taken during fire engine operations, including the idling vehicle, vehicle sirens, and water pumps. Results indicated that idling fire-engine noise levels were below 85 dBA; however, during water pump and siren use, noise levels exceeded 85 dBA, in some instances, at different locations around the trucks where firefighters would be stationed during emergency operations. To determine if the duration and use of fire fighting equipment was sufficient to result in overexposures to noise during routine training activities, 93 firefighter personal noise dosimetry samples were taken during 10 firefighter training activities. Two training activities per sampling day were monitored during each sampling event, for a mean exposure time of 70 min per day. The noise dosimetry samples were grouped based on job description to compare noise exposures between the different categories of job tasks commonly associated with fire fighting. The three job categories were interior, exterior, and engineering. Mean personal dosimetry results indicated that the average noise exposure was 78 dBA during the training activities that lasted 70 min on average. There was no significant difference in noise exposure between each of the three job categories. Although firefighters routinely use equipment and emergency response vehicles that can produce hazardous levels of noise, this study showed that the average noise levels experienced by firefighters was below generally accepted guidelines.

Network evolution induced by asynchronous stimuli through spike-timing-dependent plasticity.

PubMed

Yuan, Wu-Jie; Zhou, Jian-Fang; Zhou, Changsong

2013-01-01

In sensory neural system, external asynchronous stimuli play an important role in perceptual learning, associative memory and map development. However, the organization of structure and dynamics of neural networks induced by external asynchronous stimuli are not well understood. Spike-timing-dependent plasticity (STDP) is a typical synaptic plasticity that has been extensively found in the sensory systems and that has received much theoretical attention. This synaptic plasticity is highly sensitive to correlations between pre- and postsynaptic firings. Thus, STDP is expected to play an important role in response to external asynchronous stimuli, which can induce segregative pre- and postsynaptic firings. In this paper, we study the impact of external asynchronous stimuli on the organization of structure and dynamics of neural networks through STDP. We construct a two-dimensional spatial neural network model with local connectivity and sparseness, and use external currents to stimulate alternately on different spatial layers. The adopted external currents imposed alternately on spatial layers can be here regarded as external asynchronous stimuli. Through extensive numerical simulations, we focus on the effects of stimulus number and inter-stimulus timing on synaptic connecting weights and the property of propagation dynamics in the resulting network structure. Interestingly, the resulting feedforward structure induced by stimulus-dependent asynchronous firings and its propagation dynamics reflect both the underlying property of STDP. The results imply a possible important role of STDP in generating feedforward structure and collective propagation activity required for experience-dependent map plasticity in developing in vivo sensory pathways and cortices. The relevance of the results to cue-triggered recall of learned temporal sequences, an important cognitive function, is briefly discussed as well. Furthermore, this finding suggests a potential application for examining STDP by measuring neural population activity in a cultured neural network.

Effects of a fire alarm strobe light on fecal corticosterone metabolite concentrations in mice.

PubMed

Godfrey, Denice; Silverman, Jerald

2009-02-01

The type and location of fire alarms are important considerations in animal facility design. The Guide for the Care and Use of Laboratory Animals recommends minimizing animal exposure to such alarms. Nevertheless, it is often necessary to maintain fire alarms within animal housing or procedural areas. The authors exposed male mice to the flashing strobe light component of a standard fire alarm and evaluated mouse fecal corticosterone concentration, which is known to be an indicator of stress. Mice were exposed to the strobe light for 5 min during either the light or the dark phase of the light:dark cycle. The authors collected fecal samples every 6 h for 24 h before exposing mice to the alarm and every 6 h for 24 h after exposure. Fecal samples taken before exposure (baseline samples) showed a normal circadian pattern of corticosterone metabolite excretion. In fecal samples taken after mice were exposed to the fire alarm, metabolite concentrations did not significantly differ from baseline concentrations over time.

No Smoke Without Fire: the hidden costs of early life exposure to landscape fire emissions in Indonesia

NASA Astrophysics Data System (ADS)

Jina, A.; Marlier, M. E.

2012-12-01

Air pollution from landscape fire emissions can have devastating effects upon public health. The consequent health costs place a burden upon the economies of many nations, particularly in developing countries. Recent research has assessed contemporaneous mortality due to respiratory infections or cardiovascular disease, but little has looked at the potential long-term consequences and hidden costs of exposure to fire pollution at a population scale. The difficulty of quantifying these costs is partly due to incomplete or inaccurate health data in many developing countries, and is further compounded by sparse air pollution monitoring data. While satellite data partially compensates for this, there can still be significant gaps in data availability and difficulty in retrieving surface concentrations. In this study, we demonstrate the dramatic long-term health and human development consequences of fine particulate matter (PM2.5) exposure by using modeled PM2.5 to quantify repeated exposure to landscape fire emissions in Indonesia, which is prone to large, catastrophic fires during El Niño conditions. Surface PM2.5 concentrations at 2x2.5° resolution are obtained from GISS-E2-Puccini (the new version of the NASA GISS ModelE general circulation model), run with monthly fire emissions from the Global Fire Emissions Database version 3 (GFED3). 24-hour ambient PM2.5 concentrations across Indonesia are matched to geographically and socioeconomically representative longitudinal surveys conducted by the Indonesian government. We find important medium- to long-term morbidity associated with early life exposure to ambient air pollution from fire emissions. Our analysis indicates that children exposed to high levels of PM2.5 in utero are more likely to suffer from impaired physical and cognitive development. A one standard deviation increase in ambient air pollution, derived from the GISS-E2-Puccini model, leads to effects that are directly comparable to those from indoor air pollution. In addition, income shocks due to pollution-caused family illness can lead to an antenatal amplification of these in utero effects. The impacts of exposure in early life can be difficult to reverse, leading to a persistent effects upon a society which may contribute a significant cost to the more readily demonstrated losses associated with immediate health impacts.

Exploratory breath analyses for assessing toxic dermal exposure of firefighters during suppression of structural burns

EPA Science Inventory

Firefighters wear fireproof clothing and self-contained breathing apparatus (SCBA) during rescue and fire suppression activities to protect against acute effects from heat and toxic chemicals. Fire services are also concerned about long-term health outcomes from chemical exposure...

The health impacts and economic value of wildland fire ...

EPA Pesticide Factsheets

Introduction: Wildland fires degrade regional air quality and adversely affect human health. A growing body of epidemiology literature report increased rates of emergency department, hospital admission and premature deaths from wildfire smoke exposure. Objective: Our research aimed to characterized excess mortality and morbidity events, and the economic value of these impacts, from wildland fire smoke exposure in the U.S over a multi-year period; to date no other burden assessment has done this. Methods: We first completed a systematic review of the epidemiologic literature and then performed photochemical air quality modeling for the years 2008 to 2012 in the Continental U.S. Finally, we estimated the morbidity, mortality, and economic burden of wildland fires. Results: Our models suggest that areas including northern California, Oregon and Idaho in the West, and Florida, Louisiana and Georgia in the East were most affected by wildland fire events in the form of additional premature deaths and respiratory hospital admissions. We estimated the economic value of these cases due to short term exposures as being between $11 and $20B (2010$) per year, with a net present value of $63B (95% confidence intervals $6-$170); we estimate the value of long- term exposures as being between $76 and $130B (2010$) per year, with a net present value of $450B (95% confidence intervals $42-$1,200). Conclusion: The public health burden of wildland fires-in terms of the number and

Synchronization properties of networks of electrically coupled neurons in the presence of noise and heterogeneities.

PubMed

Ostojic, Srdjan; Brunel, Nicolas; Hakim, Vincent

2009-06-01

We investigate how synchrony can be generated or induced in networks of electrically coupled integrate-and-fire neurons subject to noisy and heterogeneous inputs. Using analytical tools, we find that in a network under constant external inputs, synchrony can appear via a Hopf bifurcation from the asynchronous state to an oscillatory state. In a homogeneous net work, in the oscillatory state all neurons fire in synchrony, while in a heterogeneous network synchrony is looser, many neurons skipping cycles of the oscillation. If the transmission of action potentials via the electrical synapses is effectively excitatory, the Hopf bifurcation is supercritical, while effectively inhibitory transmission due to pronounced hyperpolarization leads to a subcritical bifurcation. In the latter case, the network exhibits bistability between an asynchronous state and an oscillatory state where all the neurons fire in synchrony. Finally we show that for time-varying external inputs, electrical coupling enhances the synchronization in an asynchronous network via a resonance at the firing-rate frequency.

Distinct Developmental Origins Manifest in the Specialized Encoding of Movement by Adult Neurons of the External Globus Pallidus

PubMed Central

Dodson, Paul D.; Larvin, Joseph T.; Duffell, James M.; Garas, Farid N.; Doig, Natalie M.; Kessaris, Nicoletta; Duguid, Ian C.; Bogacz, Rafal; Butt, Simon J.B.; Magill, Peter J.

2015-01-01

Summary Transcriptional codes initiated during brain development are ultimately realized in adulthood as distinct cell types performing specialized roles in behavior. Focusing on the mouse external globus pallidus (GPe), we demonstrate that the potential contributions of two GABAergic GPe cell types to voluntary action are fated from early life to be distinct. Prototypic GPe neurons derive from the medial ganglionic eminence of the embryonic subpallium and express the transcription factor Nkx2-1. These neurons fire at high rates during alert rest, and encode movements through heterogeneous firing rate changes, with many neurons decreasing their activity. In contrast, arkypallidal GPe neurons originate from lateral/caudal ganglionic eminences, express the transcription factor FoxP2, fire at low rates during rest, and encode movements with robust increases in firing. We conclude that developmental diversity positions prototypic and arkypallidal neurons to fulfil distinct roles in behavior via their disparate regulation of GABA release onto different basal ganglia targets. PMID:25843402

Quantification of volatile organic compounds in smoke from prescribed burning and comparison with occupational exposure limits

NASA Astrophysics Data System (ADS)

Romagnoli, E.; Barboni, T.; Santoni, P.-A.; Chiaramonti, N.

2014-05-01

Prescribed burning represents a serious threat to personnel fighting fires due to smoke inhalation. The aim of this study was to investigate exposure by foresters to smoke from prescribed burning, focusing on exposure to volatile organic compounds (VOCs). The methodology for smoke sampling was first evaluated. Potentially dangerous compounds were identified among the VOCs emitted by smoke fires at four prescribed burning plots located around Corsica. The measured mass concentrations for several toxic VOCs were generally higher than those measured in previous studies due to the experimental framework (short sampling distance between the foresters and the flame, low combustion, wet vegetation). In particular, benzene, phenol and furfural exceeded the legal short-term exposure limits published in Europe and/or the United States. Other VOCs such as toluene, ethybenzene or styrene remained below the exposure limits. In conclusion, clear and necessary recommendations were made for protection of personnel involved in fighting fires.

Naturally occurring radioactive materials (NORMs) generated from lignite-fired power plants in Kosovo.

PubMed

Hasani, F; Shala, F; Xhixha, G; Xhixha, M K; Hodolli, G; Kadiri, S; Bylyku, E; Cfarku, F

2014-12-01

The energy production in Kosovo depends primarily on lignite-fired power plants. During coal combustion, huge amounts of fly ash and bottom ash are generated, which may result in enriched natural radionuclides; therefore, these radionuclides need to be investigated to identify the possible processes that may lead to the radiological exposure of workers and the local population. Lignite samples and NORMs of fly ash and bottom ash generated in lignite-fired power plants in Kosovo are analyzed using a gamma-ray spectrometry method for the activity concentration of natural radionuclides. The average activity concentrations of (40)K, (226)Ra and (232)Th in lignite are found to be 36 ± 8 Bq kg(-1), 9 ± 1 Bq kg(-1) and 9 ± 3 Bq kg(-1), respectively. Indications on the occurrence and geochemical behavior of uranium in the lignite matrix are suggested. The activity concentrations of natural radionuclides in fly ash and bottom ash samples are found to be concentrated from 3 to 5 times that of the feeding lignite. The external gamma-ray absorbed dose rate and the activity concentration index are calculated to assess the radiological hazard arising from ash disposal and recycling in the cement industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

49 CFR Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing

Code of Federal Regulations, 2011 CFR

2011-10-01

... plate. (3) Before exposure to the pool-fire simulation, none of the thermocouples on the thermal... simulated pool fire. (5) A pool-fire simulation test must run for a minimum of 100 minutes. The thermal... three consecutive successful simulation fire tests must be performed for each thermal protection system...

49 CFR Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing

Code of Federal Regulations, 2013 CFR

2013-10-01

... thermal response of the plate. (3) Before exposure to the pool-fire simulation, none of the thermocouples... exposed to the simulated pool fire. (5) A pool-fire simulation test must run for a minimum of 100 minutes...) A minimum of three consecutive successful simulation fire tests must be performed for each thermal...

49 CFR Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing

Code of Federal Regulations, 2014 CFR

2014-10-01

... thermal response of the plate. (3) Before exposure to the pool-fire simulation, none of the thermocouples... exposed to the simulated pool fire. (5) A pool-fire simulation test must run for a minimum of 100 minutes...) A minimum of three consecutive successful simulation fire tests must be performed for each thermal...

49 CFR Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing

Code of Federal Regulations, 2010 CFR

2010-10-01

... plate. (3) Before exposure to the pool-fire simulation, none of the thermocouples on the thermal... simulated pool fire. (5) A pool-fire simulation test must run for a minimum of 100 minutes. The thermal... three consecutive successful simulation fire tests must be performed for each thermal protection system...

49 CFR Appendix B to Part 179 - Procedures for Simulated Pool and Torch-Fire Testing

Code of Federal Regulations, 2012 CFR

2012-10-01

... plate. (3) Before exposure to the pool-fire simulation, none of the thermocouples on the thermal... simulated pool fire. (5) A pool-fire simulation test must run for a minimum of 100 minutes. The thermal... three consecutive successful simulation fire tests must be performed for each thermal protection system...

Assessing the Exposome with External Measures: Commentary on the State of the Science and Research Recommendations.

PubMed

Turner, Michelle C; Nieuwenhuijsen, Mark; Anderson, Kim; Balshaw, David; Cui, Yuxia; Dunton, Genevieve; Hoppin, Jane A; Koutrakis, Petros; Jerrett, Michael

2017-03-20

The exposome comprises all environmental exposures that a person experiences from conception throughout the life course. Here we review the state of the science for assessing external exposures within the exposome. This article reviews (a) categories of exposures that can be assessed externally, (b) the current state of the science in external exposure assessment, (c) current tools available for external exposure assessment, and (d) priority research needs. We describe major scientific and technological advances that inform external assessment of the exposome, including geographic information systems; remote sensing; global positioning system and geolocation technologies; portable and personal sensing, including smartphone-based sensors and assessments; and self-reported questionnaire assessments, which increasingly rely on Internet-based platforms. We also discuss priority research needs related to methodological and technological improvement, data analysis and interpretation, data sharing, and other practical considerations, including improved assessment of exposure variability as well as exposure in multiple, critical life stages.

Gulf War Illness-Evaluation of an Innovative Detoxification Program

DTIC Science & Technology

2015-12-01

function. Although the cause of Gulf War Illness remains uncertain, exposure to toxic chemicals from nerve gases, air pollution from oil fires and...chemicals from nerve gases, air pollution from oil fires and other sources remains as one of the most likely explanations. This study was designed...transmitted by insect vectors specific to the region, or exposure to depleted uranium . However most specialists believe that exposure to toxic chemicals is

Critical mass flux for flaming ignition of wood as a function of external radiant heat flux and moisture content

Treesearch

S. McAllister; M. Finney; J. Cohen

2011-01-01

Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion - that a sufficient amount of pyrolysis gases must be...

Risk of hospitalization for fire-related burns during extreme cold weather.

PubMed

Ayoub, Aimina; Kosatsky, Tom; Smargiassi, Audrey; Bilodeau-Bertrand, Marianne; Auger, Nathalie

2017-10-01

Environmental factors are important predictors of fires, but no study has examined the association between outdoor temperature and fire-related burn injuries. We sought to investigate the relationship between extremely cold outdoor temperatures and the risk of hospitalization for fire-related burns. We carried out a time-stratified case-crossover study of 2470 patients hospitalized for fire-related burn injuries during cold months between 1989 and 2014 in Quebec, Canada. The main exposure was the minimum outdoor temperature on the day of and the day before the burn. We computed odds ratios (OR) and 95% confidence intervals (CI) to evaluate the relationship between minimum temperature and fire-related burns, and assessed how associations varied across sex and age. Exposure to extreme cold temperature was associated with a significantly higher risk of hospitalization for fire-related burns. Compared with 0°C, exposure to a minimum temperature of -30°C was associated with an OR of 1.51 (95% CI 1.22-1.87) for hospitalization for fire-related burns. The associations were somewhat stronger for women, youth, and the elderly. Compared with 0°C, a minimum temperature of -30°C was associated with an OR for fire-related burn hospitalization of 1.65 for women (95% CI 1.13-2.40), 1.60 for age < 25 years (95% CI 1.02-2.52), and 1.73 for age ≥ 65 years (95% CI 1.08-2.77). Extremely cold outdoor temperature is a risk factor for fire-related burns. Measures to prevent fires should be implemented prior to the winter season, and enhanced during extreme cold. Copyright © 2017 Elsevier Inc. All rights reserved.

Systems for animal exposure in full-scale fire tests

NASA Technical Reports Server (NTRS)

Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

1977-01-01

Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

Combustion Processes in the Aerospace Environment

NASA Technical Reports Server (NTRS)

Huggett, Clayton

1969-01-01

The aerospace environment introduces new and enhanced fire hazards because the special atmosphere employed may increase the frequency and intensity of fires, because the confinement associated with aerospace systems adversely affects the dynamics of fire development and control, and because the hostile external environments limit fire control and rescue operations. Oxygen enriched atmospheres contribute to the fire hazard in aerospace systems by extending the list of combustible fuels, increasing the probability of ignition, and increasing the rates of fire spread and energy release. A system for classifying atmospheres according to the degree of fire hazard, based on the heat capacity of the atmosphere per mole of oxygen, is suggested. A brief exploration of the dynamics of chamber fires shows that such fires will exhibit an exponential growth rate and may grow to dangerous size in a very short time. Relatively small quantities of fuel and oxygen can produce a catastrophic fire in a closed chamber.

Personality Traits and Combat Exposure as Predictors of Psychopathology Over Time

PubMed Central

Koffel, Erin; Kramer, Mark D.; Arbisi, Paul A.; Erbes, Christopher R.; Kaler, Matthew; Polusny, Melissa A.

2016-01-01

Background Research suggests that personality traits have both direct and indirect effects on the development of psychological symptoms, with indirect effects mediated by stressful or traumatic events. This study models the direct influence of personality traits on residualized changes in internalizing and externalizing symptoms following a stressful and potentially traumatic deployment, as well as the indirect influence of personality on symptom levels mediated by combat exposure. Method We utilized structural equation modeling with a longitudinal prospective study of 522 US National Guard soldiers deployed to Iraq. Analyses were based on self-report measures of personality, combat exposure, and internalizing and externalizing symptoms. Results Both pre-deployment Disconstraint and externalizing symptoms predicted combat exposure, which in turn predicted internalizing and externalizing symptoms. There was a significant indirect effect for pre-deployment externalizing symptoms on post-deployment externalizing via combat exposure (p < .01). Negative Emotionality and pre-deployment internalizing symptoms directly predicted post-deployment internalizing symptoms, but both were unrelated to combat exposure. No direct effects of personality on residualized changes in externalizing symptoms were found. Conclusions Baseline symptom dimensions had significant direct and indirect effects on post-deployment symptoms. Controlling for both pre-exposure personality and symptoms, combat experiences remained positively related to both internalizing and externalizing symptoms. Implications for diagnostic classification are discussed. PMID:26347314

Accelerated weathering of fire-retardant-treated wood for fire testing

Treesearch

Robert H. White

2009-01-01

Fire-retardant-treated products for exterior applications must be subjected to actual or accelerated weathering prior to fire testing. For fire-retardant-treated wood, the two accelerated weathering methods have been Method A and B of ASTM D 2898. The rain test is Method A of ASTM D 2898. Method B includes exposures to ultraviolet (UV) sunlamps in addition to water...

Effectiveness of fire-retardant treatments for shingles after 10 years of outdoor weathering

Treesearch

S. L. LeVan; C. A. Holmes

Some building codes require wood shingles to be fire-retardant treated. Because exterior fire-retardant treatments are subjected to weathering, treatment durability and leach resistance are critical for insuring adequate fire protection. We examined the effectiveness of various fire-retardant treatments on wood after 0, 2, 5, and 10 years of outdoor exposure. We used a...

Clarifying the role of fire heat and daily temperature fluctuations as germination cues for Mediterranean Basin obligate seeders

PubMed Central

Santana, Victor M.; Baeza, M. Jaime; Blanes, M. Carmen

2013-01-01

Background and Aims This study aims to determine the role that both direct effects of fire and subsequent daily temperature fluctuations play in the seed bank dynamics of obligate seeders from the Mediterranean Basin. The short yet high soil temperatures experienced due to passage of fire are conflated with the lower, but longer, temperatures experienced by daily fluctuations which occur after removing vegetation. These germination cues are able to break seed dormancy, but it is difficult to assess their specific level of influence because they occur consecutively after summer fires, just before the flush of germination in the wet season (autumn). Methods By applying experimental fires, seed treatments were imposed that combined fire exposure/non-fire exposure with exposure to microhabitats under a gradient of disturbance (i.e. gaps opened by fire, mechanical brushing and intact vegetation). The seeds used were representative of the main families of obligate seeders (Ulex parviflorus, Cistus albidus and Rosmarinus officinalis). Specifically, an assessment was made of (1) the proportion of seeds killed by fire, (2) seedling emergence under field conditions and (3) seeds which remained ungerminated in soil. Key Results For the three species studied, the factors that most influenced seedling emergence and seeds remaining ungerminated were microhabitats with higher temperature fluctuations after fire (gaps opened by fire and brushing treatments). The direct effect of fire decreased the seedling emergence of U. parviflorus and reduced the proportion of seeds of R. officinalis remaining ungerminated. Conclusions The relevance of depleting vegetation (and subsequent daily temperature fluctuation in summer) suggests that studies focusing on lower temperature thresholds for breaking seed dormancy are required. This fact also supports the hypothesis that the seeding capacity in Mediterranean Basin obligate seeders may have evolved as a response to a wide range of disturbances, and not exclusively to fire. PMID:23129044

Exposure to Externalizing Peers in Early Childhood: Homophily and Peer Contagion Processes.

ERIC Educational Resources Information Center

Hanish, Laura D.; Martin, Carol Lynn; Fabes, Richard A.; Leonard, Stacie; Herzog, Melissa

2005-01-01

Guided by a transactional model, we examined the predictors and effects of exposure to externalizing peers in a low-risk sample of preschoolers and kindergarteners. On the basis of daily observations of peer interactions, we calculated measures of total exposure to externalizing peers and measures of exposure to same- and other-sex externalizing…

How Does The Climate Change?

NASA Astrophysics Data System (ADS)

Jones, R. N.

2011-12-01

In 1997, maximum temperature in SE Australia shifted up by 0.8°C at pH0<0.01. Rainfall decreased by 13% in 1997-2010 compared to 1900-1996. Statistically significant shifts also occur in impact indicators: baumé levels in winegrapes shift >21 days earlier from 1998, streamflow records decrease by 30-70% from 1997 and annual mean forest fire danger index increased by 38% from 1997. Despite catastrophic fires killing 178 people in early 2009, the public remains unaware of this large change in their exposure. When regional temperature was separated into internally and externally forced components, the latter component was found to warm in two steps, in 1968-73 and 1997. These dates coincide with shifts in zonal mean temperature (24-44S; Figure 1). Climate model output shows similar step and trend behavior. Tests run on zonal, hemispheric and global mean temperature observations found shifts in all regions. 1997 marks a shift in global temperature of 0.3°C at pH0<0.01. Similar shifts occur in long-term tide gauge records around the globe (e.g., Figure 2) and in ocean heat content. The prevailing paradigm for how climate variables change is signal-noise construct combining a smooth signal with variations caused by internal climate variability. There seems to be no sound theoretical basis for this assumption. On the contrary, complex system behavior would suggest non-linear responses to externally forced change, especially at the regional scale. Some of our most basic assumptions about how climate changes may need to be re-examined.

EFFECT OF CONVENTIONAL AND ADVANCED COAL CONVERSION BY-PRODUCTS ON THE PULMONARY SYSTEM

EPA Science Inventory

To evaluate the environmental impact of different energy technologies, fly ash samples collected from a coal-fired and from an oil-fired electric power plant were used in aerosol inhalation exposures of mice. The effects of multiple 3-h exposures to the fly ash particles at 2 and...

Guide to monitoring smoke exposure of wildland firefighters.

Treesearch

Tim E. Reinhardt; Roger D. Ottmar; Michael J. Hallett

1999-01-01

Fire managers and safety officers concerned with smoke exposure among fire crews can use electronic carbon monoxide (CO) monitors to track and prevent overexposure to smoke. Commonly referred to as dosimeters, these lightweight instruments measure the concentration of CO in the air the firefighter's breathe. This guide outlines the protocol developed for sampling...

Intoxication by cyanide in fires: a study in monkeys using polyacrylonitrile

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

Purser, D.A.; Grimshaw, P.; Berrill, K.R.

It is suspected that hydrogen cyanide (HCN) may be an important factor in incapacitating fire victims, but the effects of sublethal exposures are not well characterized. Also, the incapacitating effects of fire atmospheres result from exposure to a mixture of toxic products so that the contribution from each component is difficult to determine. The mechanisms of incapacitation in monkeys exposed to the pyrolysis products of polyacrylonitrile (PAN) were compared to those resulting from low level HCN gas exposures. The physiological effects of the PAN atmospheres were almost identical to those of HCN gas alone. They consisted of hyperventilation, followed bymore » loss of consciousness after 1-5 min, bradycardia with arrhythmias and T-wave abnormalities, and were followed by a rapid recovery after exposure. Hydrogen cyanide is considered to be the major toxic product formed by the pyrolysis of PAN. It is suggested that HCN may produce rapid incapacitation at low blood levels of cyanide in fires, while death may occur later due to carbon monoxide poisoning or other factors.« less

Exposure assessment of JAVELIN missile combustion products

NASA Astrophysics Data System (ADS)

Lundy, Donald O.; Langford, Roland E.

1994-02-01

Characterization and analysis of combustion products resulting from firing the JAVELIN missile were performed. Of those combustion products analyzed, it was determined that airborne lead concentrations exceeded the OSHA PEL of 50 micrograms each time the missile was fired while in the enclosure. Since the OSHA PEL standard is based upon a continuous rather than a short-term exposures blood lead concentrations were sought to ascertain the relationship between a short duration airborne exposure and its physiological effect on the body. Blood lead levels were taken on 49 test subjects prior to various JAVELIN missile test firings. Of those 49, 21 were outfitted With personal sampling equipment to determine airborne concentrations at the Assistant Gunner and Gunner positions. Periodic blood sampling after a single exposure showed an average increase of 2.27 micrograms/dL for all test subjects. Recommendations were made to consider changes in the positioning of the enclosure inhabitants to minimize airborne lead concentrations, to limit the number of missiles fired (situation dependent), and replacement of the lead B-resorcyolate with a non-lead containing burn rate modifier for the launch motor.

Exploratory breath analyses for assessing toxic dermal exposures of firefighters during suppression of structural burns.

PubMed

Pleil, Joachim D; Stiegel, Matthew A; Fent, Kenneth W

2014-09-01

Firefighters wear fireproof clothing and self-contained breathing apparatus (SCBA) during rescue and fire suppression activities to protect against acute effects from heat and toxic chemicals. Fire services are also concerned about long-term health outcomes from chemical exposures over a working lifetime, in particular about low-level exposures that might serve as initiating events for adverse outcome pathways (AOP) leading to cancer. As part of a larger US National Institute for Occupational Safety and Health (NIOSH) study of dermal exposure protection from safety gear used by the City of Chicago firefighters, we collected pre- and post-fire fighting breath samples and analyzed for single-ring and polycyclic aromatic hydrocarbons as bioindicators of occupational exposure to gas-phase toxicants. Under the assumption that SCBA protects completely against inhalation exposures, any changes in the exhaled profile of combustion products were attributed to dermal exposures from gas and particle penetration through the protective clothing. Two separate rounds of firefighting activity were performed each with 15 firefighters per round. Exhaled breath samples were collected onto adsorbent tubes and analyzed with gas-chromatography-mass spectrometry (GC-MS) with a targeted approach using selective ion monitoring. We found that single ring aromatics and some PAHs were statistically elevated in post-firefighting samples of some individuals, suggesting that fire protective gear may allow for dermal exposures to airborne contaminants. However, in comparison to a previous occupational study of Air Force maintenance personnel where similar compounds were measured, these exposures are much lower suggesting that firefighters' gear is very effective. This study suggests that exhaled breath sampling and analysis for specific targeted compounds is a suitable method for assessing systemic dermal exposure in a simple and non-invasive manner.

Exposure–response relationships for select cancer and non-cancer health outcomes in a cohort of US firefighters from San Francisco, Chicago and Philadelphia (1950–2009)

PubMed Central

Daniels, Robert D.; Bertke, Stephen; Dahm, Matthew M.; Yiin, James H.; Kubale, Travis L.; Hales, Thomas R.; Baris, Dalsu; Zahm, Shelia H.; Beaumont, James J.; Waters, Kathleen M.; Pinkerton, Lynne E.

2015-01-01

Objectives To examine exposure–response relationships between surrogates of firefighting exposure and select outcomes among previously studied US career firefighters. Methods Eight cancer and four non-cancer outcomes were examined using conditional logistic regression. Incidence density sampling was used to match each case to 200 controls on attained age. Days accrued in firefighting assignments (exposed-days), run totals (fire-runs) and run times (fire-hours) were used as exposure surrogates. HRs comparing 75th and 25th centiles of lagged cumulative exposures were calculated using loglinear, linear, log-quadratic, power and restricted cubic spline general relative risk models. Piecewise constant models were used to examine risk differences by time since exposure, age at exposure and calendar period. Results Among 19 309 male firefighters eligible for the study, there were 1333 cancer deaths and 2609 cancer incidence cases. Significant positive associations between fire-hours and lung cancer mortality and incidence were evident. A similar relation between leukaemia mortality and fire-runs was also found. The lung cancer associations were nearly linear in cumulative exposure, while the association with leukaemia mortality was attenuated at higher exposure levels and greater for recent exposures. Significant negative associations were evident for the exposure surrogates and colorectal and prostate cancers, suggesting a healthy worker survivor effect possibly enhanced by medical screening. Conclusions Lung cancer and leukaemia mortality risks were modestly increasing with firefighter exposures. These findings add to evidence of a causal association between firefighting and cancer. Nevertheless, small effects merit cautious interpretation. We plan to continue to follow the occurrence of disease and injury in this cohort. PMID:25673342

Occupational overpressure exposure of breachers and military personnel

NASA Astrophysics Data System (ADS)

Kamimori, G. H.; Reilly, L. A.; LaValle, C. R.; Olaghere Da Silva, U. B.

2017-11-01

Military and law enforcement personnel may be routinely and repetitively exposed to low-level blast (LLB) overpressure during training and in operations. This repeated exposure has been associated with symptoms similar to that reported for sports concussion. This study reports LLB exposure for various military and law enforcement sources in operational training environments. Peak overpressure and impulse data are presented from indoor breaching, outdoor breaching, shotgun door breaching, small arms discharge, and mortar and artillery fire missions. Data were collected using the Black Box Biometrics (B3) Blast Gauge sensors. In all cases, sensors were attached to the operators and, where possible, also statically mounted to walls or other fixed structures. Peak overpressures from below 1 psi (7 kPa) to over 12 psi (83 kPa) were recorded; all values reported are uncorrected for incidence angle to the blast exposure source. The results of these studies indicate that the current minimum safe distance calculations are often inaccurate for both indoor and outdoor breaching scenarios as true environmental exposure can consistently exceed the 4 psi (28 kPa) incident safe threshold prescribed by U.S. Army doctrine. While ballistic (shotgun) door breaching and small arms firing only expose the operator to low peak exposure levels, the sheer number of rounds fired during training may result in an excessive cumulative exposure. Mortar and artillery crew members received significantly different overpressure and impulse exposures based on their position (job) relative to the weapon. As both the artillery and mortar crews commonly fire hundreds of rounds during a single training session they are also likely to receive high cumulative exposures. These studies serve to provide the research community with estimates for typical operator exposure across a range of operational scenarios or in the discharge of various weapons systems.

The health impacts and economic value of wildland fire episodes in the U.S.: 2008-2012.

PubMed

Fann, Neal; Alman, Breanna; Broome, Richard A; Morgan, Geoffrey G; Johnston, Fay H; Pouliot, George; Rappold, Ana G

2018-01-01

Wildland fires degrade air quality and adversely affect human health. A growing body of epidemiology literature reports increased rates of emergency departments, hospital admissions and premature deaths from wildfire smoke exposure. Our research aimed to characterize excess mortality and morbidity events, and the economic value of these impacts, from wildland fire smoke exposure in the U.S. over a multi-year period; to date no other burden assessment has done this. We first completed a systematic review of the epidemiologic literature and then performed photochemical air quality modeling for the years 2008 to 2012 in the continental U.S. Finally, we estimated the morbidity, mortality, and economic burden of wildland fires. Our models suggest that areas including northern California, Oregon and Idaho in the West, and Florida, Louisiana and Georgia in the East were most affected by wildland fire events in the form of additional premature deaths and respiratory hospital admissions. We estimated the economic value of these cases due to short term exposures as being between $11 and $20B (2010$) per year, with a net present value of $63B (95% confidence intervals $6-$170); we estimate the value of long-term exposures as being between $76 and $130B (2010$) per year, with a net present value of $450B (95% confidence intervals $42-$1200). The public health burden of wildland fires-in terms of the number and economic value of deaths and illnesses-is considerable. Published by Elsevier B.V.

Impact of Reduced Maternal Exposures to Wood Smoke from an Introduced Chimney Stove on Newborn Birth Weight in Rural Guatemala

PubMed Central

Bruce, Nigel; Eskenazi, Brenda; Diaz, Anaite; Pope, Daniel; Smith, Kirk R.

2011-01-01

Background: A growing body of evidence indicates a relationship between household indoor air pollution from cooking fires and adverse neonatal outcomes, such as low birth weight (LBW), in resource-poor countries. Objective: We examined the effect of reduced wood smoke exposure in pregnancy on LBW of Guatemalan infants in RESPIRE (Randomized Exposure Study of Pollution Indoors and Respiratory Effects). Methods: Pregnant women (n = 266) either received a chimney stove (intervention) or continued to cook over an open fire (control). Between October 2002 and December 2004 we weighed 174 eligible infants (69 to mothers who used a chimney stove and 105 to mothers who used an open fire during pregnancy) within 48 hr of birth. Multivariate linear regression and adjusted odds ratios (ORs) were used to estimate differences in birth weight and LBW (< 2,500 g) associated with chimney-stove versus open-fire use during pregnancy. Results: Pregnant women using chimney stoves had a 39% reduction in mean exposure to carbon monoxide compared with those using open fires. LBW prevalence was high at 22.4%. On average, infants born to mothers who used a stove weighed 89 g more [95% confidence interval (CI), –27 to 204 g] than infants whose mothers used open fires after adjusting for maternal height, diastolic blood pressure, gravidity, and season of birth. The adjusted OR for LBW was 0.74 (95% CI, 0.33–1.66) among infants of stove users compared with open-fire users. Average birth weight was 296 g higher (95% CI, 109–482 g) in infants born during the cold season (after harvest) than in other infants; this unanticipated finding may reflect the role of maternal nutrition on birth weight in an impoverished region. Conclusions: A chimney stove reduced wood smoke exposures and was associated with reduced LBW occurrence. Although not statistically significant, the estimated effect was consistent with previous studies. PMID:21652290

Effect of protective filters on fire fighter respiratory health: field validation during prescribed burns.

PubMed

De Vos, Annemarie J B M; Cook, Angus; Devine, Brian; Thompson, Philip J; Weinstein, Philip

2009-01-01

Bushfire smoke contains a range of air toxics. To prevent inhalation of these toxics, fire fighters use respiratory equipment. Yet, little is known about the effectiveness of the equipment on the fire ground. Experimental trials in a smoke chamber demonstrated that, the particulate/organic vapor/formaldehyde (POVF) filter performed best under simulated conditions. This article reports on the field validation trials during prescribed burns in Western Australia. Sixty-seven career fire fighters from the Fire and Emergency Services Authority of Western Australia were allocated one of the three types of filters. Spirometry, oximetry, self-reported symptom, and personal air sampling data were collected before, during and after exposure to bushfire smoke from prescribed burns. Declines in FEV(1) and SaO(2) were demonstrated after 60 and 120 min exposure. A significant higher number of participants in the P filter group reported increases in respiratory symptoms after the exposure. Air sampling inside the respirators demonstrated formaldehyde levels significantly higher in the P filter group compared to the POV and the POVF filter group. The field validation trials during prescribed burns supported the findings from the controlled exposure trials in the smoke chamber. Testing the effectiveness of three types of different filters under bushfire smoke conditions in the field for up to 2 hr demonstrated that the P filter is ineffective in filtering out respiratory irritants. The performance of the POV and the POVF filter appears to be equally effective after 2 hr bushfire smoke exposure in the field.

Fire resistance of structural composite lumber products

Treesearch

Robert H. White

2006-01-01

Use of structural composite lumber products is increasing. In applications requiring a fire resistance rating, calculation procedures are used to obtain the fire resistance rating of exposed structural wood products. A critical factor in the calculation procedures is char rate for ASTM E 119 fire exposure. In this study, we tested 14 structural composite lumber...

Forest Fire Smoke Exposures and Out-of-Hospital Cardiac Arrests in Melbourne, Australia: A Case-Crossover Study.

PubMed

Dennekamp, Martine; Straney, Lahn D; Erbas, Bircan; Abramson, Michael J; Keywood, Melita; Smith, Karen; Sim, Malcolm R; Glass, Deborah C; Del Monaco, Anthony; Haikerwal, Anjali; Tonkin, Andrew M

2015-10-01

Millions of people can potentially be exposed to smoke from forest fires, making this an important public health problem in many countries. In this study we aimed to measure the association between out-of-hospital cardiac arrest (OHCA) and forest fire smoke exposures in a large city during a severe forest fire season, and estimate the number of excess OHCAs due to the fire smoke. We investigated the association between particulate matter (PM) and other air pollutants and OHCA using a case-crossover study of adults (≥ 35 years of age) in Melbourne, Australia. Conditional logistic regression models were used to derive estimates of the percent change in the rate of OHCA associated with an interquartile range (IQR) increase in exposure. From July 2006 through June 2007, OHCA data were collected from the Victorian Ambulance Cardiac Arrest Registry. Hourly air pollution concentrations and meteorological data were obtained from a central monitoring site. There were 2,046 OHCAs with presumed cardiac etiology during our study period. Among men during the fire season, greater increases in OHCA were observed with IQR increases in the 48-hr lagged PM with diameter ≤ 2.5 μm (PM2.5) (8.05%; 95% CI: 2.30, 14.13%; IQR = 6.1 μg/m(3)) or ≤ 10 μm (PM10) (11.1%; 95% CI: 1.55, 21.48%; IQR = 13.7 μg/m(3)) and carbon monoxide (35.7%; 95% CI: 8.98, 68.92%; IQR = 0.3 ppm). There was no significant association between the rate of OHCA and air pollutants among women. One hundred seventy-four "fire-hours" (i.e., hours in which Melbourne's air quality was affected by forest fire smoke) were identified during 12 days of the 2006/2007 fire season, and 23.9 (95% CI: 3.1, 40.2) excess OHCAs were estimated to occur due to elevations in PM2.5 during these fire-hours. This study found an association between exposure to forest fire smoke and an increase in the rate of OHCA. These findings have implications for public health messages to raise community awareness and for planning of emergency services during forest fire seasons.

Reliability study of an emerging fire suppression system

DOE PAGES

Miller, David A.; Rossati, Lyric M.; Fritz, Nathan K.; ...

2015-11-01

Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Plutonium gloveboxes are known to present harsh environmental conditions for polymer materials, these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. The primary component of interest in self-contained fire extinguishers is the nylon 6-6 machined tube that comprises the main body of the system.Thermo-mechanical modeling and characterization of nylon 6-6 for use in plutonium glovebox applications has been carried out. Data has been generated regarding property degradation leading to poor, or reduced, engineering performancemore » of nylon 6-6 components. In this study, nylon 6-6 tensile specimens conforming to the casing of self-contained fire extinguisher systems have been exposed to hydrochloric, nitric, and sulfuric acids. This information was used to predict the performance of a load bearing engineering component comprised of nylon 6-6 and designed to operate in a consistent manner over a specified time period. The study provides a fundamental understanding of the engineering performance of the fire suppression system and the effects of environmental degradation due to acid exposure on engineering performance. Data generated help identify the limitations of self-contained fire extinguishers. No critical areas of concern for plutonium glovebox applications of nylon 6-6 have been identified when considering exposure to mineral acid.« less

Reliability study of an emerging fire suppression system

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

Miller, David A.; Rossati, Lyric M.; Fritz, Nathan K.

Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Plutonium gloveboxes are known to present harsh environmental conditions for polymer materials, these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. The primary component of interest in self-contained fire extinguishers is the nylon 6-6 machined tube that comprises the main body of the system.Thermo-mechanical modeling and characterization of nylon 6-6 for use in plutonium glovebox applications has been carried out. Data has been generated regarding property degradation leading to poor, or reduced, engineering performancemore » of nylon 6-6 components. In this study, nylon 6-6 tensile specimens conforming to the casing of self-contained fire extinguisher systems have been exposed to hydrochloric, nitric, and sulfuric acids. This information was used to predict the performance of a load bearing engineering component comprised of nylon 6-6 and designed to operate in a consistent manner over a specified time period. The study provides a fundamental understanding of the engineering performance of the fire suppression system and the effects of environmental degradation due to acid exposure on engineering performance. Data generated help identify the limitations of self-contained fire extinguishers. No critical areas of concern for plutonium glovebox applications of nylon 6-6 have been identified when considering exposure to mineral acid.« less

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

Akagi, Sheryl; Burling, Ian R.; Mendoza, Albert

We report trace-gas emission factors from three pine-understory prescribed fires in South Carolina, U.S. measured during the fall of 2011. The fires were an attempt to simulate high-intensity burns and the fuels included mature pine stands not frequently subjected to prescribed fire that were lit following a sustained period of drought. In this work we focus on the emission factor measurements made using a fixed open-path gas analyzer Fourier transform infrared (FTIR) system. We compare these emission factors with those measured using a roving, point sampling, land-based FTIR and an airborne FTIR that were deployed on the same fires. Wemore » also compare to emission factors measured by a similar open-path FTIR system deployed on savanna fires in Africa. The data suggest that the method in which the smoke is sampled can strongly influence the relative abundance of the emissions that are observed. The airborne FTIR probed the bulk of the emissions, which were lofted in the convection column and the downwind chemistry while the roving ground-based point sampling FTIR measured the contribution of individual residual smoldering combustion fuel elements scattered throughout the burn site. The open-path FTIR provided a fixed path-integrated sample of emissions produced directly upwind mixed with emissions that were redirected by wind gusts, or right after ignition and before the adjacent plume achieved significant vertical development. It typically probed two distinct combustion regimes, “flaming-like” (immediately after adjacent ignition) and “smoldering-like”, denoted “early” and “late”, respectively. The calculated emission factors from open-path measurements were closer to the airborne than to the point measurements, but this could vary depending on the calculation method or from fire to fire given the changing MCE and dynamics over the duration of a typical burn. The emission factors for species whose emissions are not highly fuel dependent (e.g. CH4 and CH3OH) from all three systems can be plotted versus modified combustion efficiency and fit to a single consistent trend suggesting that differences between the systems for these species may be mainly due to the unique mix of flaming and smoldering that each system sampled. For other more fuel dependent species, the different fuels sampled also likely contributed to platform differences in emission factors. The path-integrated sample of the ground-level smoke layer adjacent to the fire provided by the open-path measurements is important for estimating fire-line exposure to smoke for wildland fire personnel. We provide a table of estimated fire-line exposures for numerous known air toxics based on synthesizing results from several studies. Our data suggest that peak exposures are more likely to challenge permissible exposure limits for wildland fire personnel than shift-average exposures.« less

Analyzing wildfire exposure on Sardinia, Italy

NASA Astrophysics Data System (ADS)

Salis, Michele; Ager, Alan A.; Arca, Bachisio; Finney, Mark A.; Alcasena, Fermin; Bacciu, Valentina; Duce, Pierpaolo; Munoz Lozano, Olga; Spano, Donatella

2014-05-01

We used simulation modeling based on the minimum travel time algorithm (MTT) to analyze wildfire exposure of key ecological, social and economic features on Sardinia, Italy. Sardinia is the second largest island of the Mediterranean Basin, and in the last fifty years experienced large and dramatic wildfires, which caused losses and threatened urban interfaces, forests and natural areas, and agricultural productions. Historical fires and environmental data for the period 1995-2009 were used as input to estimate fine scale burn probability, conditional flame length, and potential fire size in the study area. With this purpose, we simulated 100,000 wildfire events within the study area, randomly drawing from the observed frequency distribution of burn periods and wind directions for each fire. Estimates of burn probability, excluding non-burnable fuels, ranged from 0 to 1.92x10-3, with a mean value of 6.48x10-5. Overall, the outputs provided a quantitative assessment of wildfire exposure at the landscape scale and captured landscape properties of wildfire exposure. We then examined how the exposure profiles varied among and within selected features and assets located on the island. Spatial variation in modeled outputs resulted in a strong effect of fuel models, coupled with slope and weather. In particular, the combined effect of Mediterranean maquis, woodland areas and complex topography on flame length was relevant, mainly in north-east Sardinia, whereas areas with herbaceous fuels and flat areas were in general characterized by lower fire intensity but higher burn probability. The simulation modeling proposed in this work provides a quantitative approach to inform wildfire risk management activities, and represents one of the first applications of burn probability modeling to capture fire risk and exposure profiles in the Mediterranean basin.

Estimated Internal and External Radiation Exposure of Caregivers of Patients With Pediatric Neuroblastoma Undergoing 131I Metaiodobenzylguanidine Therapy: A Prospective Pilot Study.

PubMed

Han, Sangwon; Yoo, Seon Hee; Koh, Kyung-Nam; Lee, Jong Jin

2017-04-01

Current recommendations suggest that family members should participate in the care of children receiving in-hospital I metaiodobenzylguanidine (MIBG) therapy for neuroblastoma. The present study aimed to measure the external radiation exposure and estimate the internal radiation exposure of caregivers during the hospital stay for I MIBG therapy. Caregivers received radiation safety instructions and a potassium iodide solution for thyroid blockade before patient admission. External radiation exposure was determined using a personal pocket dosimeter. Serial 24-hour urine samples were collected from caregivers during the hospital stay. Estimated internal radiation exposure was calculated based on the urine activity. Twelve cases (mean age, 6.2 ± 3.5 years; range, 2-13 years) were enrolled. The mean administered activity was 233.3 ± 74.9 (range, 150.0-350.0) mCi. The mean external radiation dose was 5.8 ± 7.2 (range, 0.8-19.9) mSv. Caregivers of children older than 4 years had significantly less external radiation exposure than those of children younger than 4 years (1.9 ± 1.0 vs 16.4 ± 5.0 mSv; P = 0.012). The mean estimated internal radiation dose was 11.3 ± 10.2 (range, 1.0-29.8) μSv. Caregivers receive both external and internal radiation exposure while providing in-hospital care to children receiving I MIBG therapy for neuroblastoma. However, the internal radiation exposure was negligible compared with the external radiation exposure.

External occupational exposures in some NORM industries located at the South-West of Spain

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

Bolivar, J. P.; Garcia-Tenorio, R.

2008-08-07

Detailed mappings of the external exposures which can be received by the workers in two NORM industrial factories located at the South-West of Spain have been performed: one devoted to the production of phosphoric acid, and the other devoted to the production of titanium dioxide pigments. In most places of the analyzed factories, the external exposures are moderated, although in some specific points, and associated to the presence of scales, their values are clearly higher. Nevertheless, under normal running conditions, the contribution of the external exposures to the effective doses received by the workers is lower than 1 mSv/y becausemore » the worker occupancy factors values are very low in the places with the highest external exposures.« less

Critical mass flux for flaming ignition of dead, dry wood as a function of external radiant heat flux and oxidizer flow velocity

Treesearch

Sara McAllister; Mark Finney; Jack Cohen

2010-01-01

Extreme weather often contributes to crown fires, where the fire spreads from one tree crown to the next as a series of piloted ignitions. An important aspect in predicting crown fires is understanding the ignition of fuel particles. The ignition criterion considered in this work is the critical mass flux criterion – that a sufficient amount of pyrolysis gases must be...

Community Vulnerability to Health Impacts of Wildland Fire Smoke Exposure.

PubMed

Rappold, Ana G; Reyes, Jeanette; Pouliot, George; Cascio, Wayne E; Diaz-Sanchez, David

2017-06-20

Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community Health-Vulnerability Index (CHVI) based on factors known to increase the risks of health effects from air pollution and wildfire smoke exposures. These factors included county prevalence rates for asthma in children and adults, chronic obstructive pulmonary disease, hypertension, diabetes, obesity, percent of population 65 years of age and older, and indicators of socioeconomic status including poverty, education, income and unemployment. Using air quality simulated for the period between 2008 and 2012 over the continental U.S. we also characterized the population size at risk with respect to the level and duration of exposure to fire-originated fine particulate matter (fire-PM 2.5 ) and CHVI. We estimate that 10% of the population (30.5 million) lived in the areas where the contribution of fire-PM 2.5 to annual average ambient PM 2.5 was high (>1.5 μg/m 3 ) and that 10.3 million individuals experienced unhealthy air quality levels for more than 10 days due to smoke. Using CHVI we identified the most vulnerable counties and determined that these communities experience more smoke exposures in comparison to less vulnerable communities.

Industrial concessions, fires and air pollution in Equatorial Asia

NASA Astrophysics Data System (ADS)

Spracklen, D. V.; Reddington, C. L.; Gaveau, D. L. A.

2015-09-01

Forest and peatland fires in Indonesia emit large quantities of smoke leading to poor air quality across Equatorial Asia. Marlier et al (2015 Environ. Res. Lett. 10 085005) explore the contribution of fires occurring on oil palm, timber (wood pulp and paper) and natural forest logging concessions to smoke emissions and exposure of human populations to the resulting air pollution. They find that one third of the population exposure to smoke across Equatorial Asia is caused by fires in oil palm and timber concessions in Sumatra and Kalimantan. Logging concessions have substantially lower fire emissions, and contribute less to air quality degradation. This represents a compelling justification to prevent reclassification of logging concessions into oil palm or timber concessions after logging. This can be achieved by including logged forests in the Indonesian moratorium on new plantations in forested areas.

Sociogenomics of cooperation and conflict during colony foundation in the fire ant Solenopsis invicta

USDA-ARS?s Scientific Manuscript database

The genomic state of an individual results from the interplay between its internal condition and the external environment, which may include the social environment. The link between genes and social environment is clearly visible during the process of colony founding in the fire ant Solenopsis invic...

External charring and fire scarring in three western conifers

Treesearch

E. K. Sutherland; Josh Farella; David K Wright; Ian Hyp; K. T. Smith; Donald A. Falk; Estelle Arbellay; Markus Stoffel

2013-01-01

Fires that injure but do not kill trees cause scars used as proxies for the reconstruction of wildfire history. Understanding about these wildfires - and their relationship to vegetation dynamics and climate - has profoundly affected wildfire and land management policy globally. To better understand scarring in the context of wildfire behavior, landscape and biological...

Wildfire smoke exposure and cardiopulmonary hospitalizations among those over age 65 in the United States

EPA Science Inventory

Background: The health implications of excess PM2.5 due to wildland fire smoke are not well understood. Very few studies have assessed the effect of wildland fire smoke from multiple fires across the US. Methods: We estimated daily concentrations of PM2.5 due to wildland fire smo...

Environmental Assessment for the Warren Station externally fired combined cycle demonstration project

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

NONE

1995-04-01

The proposed Penelec project is one of 5 projects for potential funding under the fifth solicitation under the Clean Coal Technology program. In Penelec, two existing boilers would be replaced at Warren Station, PA; the new unit would produce 73 MW(e) in a combined cycle mode (using both gas-fired and steam turbines). The project would fill the need for a full utility-size demonstration of externally fire combined cycle (EFCC) technology as the next step toward commercialization. This environmental assessment was prepared for compliance with NEPA; its purpose is to provide sufficient basis for determining whether to prepare an environmental impactmore » statement or to issue a finding of no significant impact. It is divided into the sections: purpose and need for proposed action; alternatives; brief description of affected environment; environmental consequences, including discussion of commercial operation beyond the demonstration period.« less

Exposure-response relationships for select cancer and non-cancer health outcomes in a cohort of U.S. firefighters from San Francisco, Chicago and Philadelphia (1950-2009).

PubMed

Daniels, Robert D; Bertke, Stephen; Dahm, Matthew M; Yiin, James H; Kubale, Travis L; Hales, Thomas R; Baris, Dalsu; Zahm, Shelia H; Beaumont, James J; Waters, Kathleen M; Pinkerton, Lynne E

2015-10-01

To examine exposure-response relationships between surrogates of firefighting exposure and select outcomes among previously studied US career firefighters. Eight cancer and four non-cancer outcomes were examined using conditional logistic regression. Incidence density sampling was used to match each case to 200 controls on attained age. Days accrued in firefighting assignments (exposed-days), run totals (fire-runs) and run times (fire-hours) were used as exposure surrogates. HRs comparing 75th and 25th centiles of lagged cumulative exposures were calculated using loglinear, linear, log-quadratic, power and restricted cubic spline general relative risk models. Piecewise constant models were used to examine risk differences by time since exposure, age at exposure and calendar period. Among 19,309 male firefighters eligible for the study, there were 1333 cancer deaths and 2609 cancer incidence cases. Significant positive associations between fire-hours and lung cancer mortality and incidence were evident. A similar relation between leukaemia mortality and fire-runs was also found. The lung cancer associations were nearly linear in cumulative exposure, while the association with leukaemia mortality was attenuated at higher exposure levels and greater for recent exposures. Significant negative associations were evident for the exposure surrogates and colorectal and prostate cancers, suggesting a healthy worker survivor effect possibly enhanced by medical screening. Lung cancer and leukaemia mortality risks were modestly increasing with firefighter exposures. These findings add to evidence of a causal association between firefighting and cancer. Nevertheless, small effects merit cautious interpretation. We plan to continue to follow the occurrence of disease and injury in this cohort. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

Airborne contaminants during controlled residential fires.

PubMed

Fent, Kenneth W; Evans, Douglas E; Babik, Kelsey; Striley, Cynthia; Bertke, Stephen; Kerber, Steve; Smith, Denise; Horn, Gavin P

2018-05-01

In this study, we characterize the area and personal air concentrations of combustion byproducts produced during controlled residential fires with furnishings common in 21 st century single family structures. Area air measurements were collected from the structure during active fire and overhaul (post suppression) and on the fireground where personnel were operating without any respiratory protection. Personal air measurements were collected from firefighters assigned to fire attack, victim search, overhaul, outside ventilation, and command/pump operator positions. Two different fire attack tactics were conducted for the fires (6 interior and 6 transitional) and exposures were compared between the tactics. For each of the 12 fires, firefighters were paired up to conduct each job assignment, except for overhaul that was conducted by 4 firefighters. Sampled compounds included polycyclic aromatic hydrocarbons (PAHs), volatile organic compounds (VOCs, e.g., benzene), hydrogen cyanide (HCN), and particulate (area air sampling only). Median personal air concentrations for the attack and search firefighters were generally well above applicable short-term occupational exposure limits, with the exception of HCN measured from search firefighters. Area air concentrations of all measured compounds decreased after suppression. Personal air concentrations of total PAHs and benzene measured from some overhaul firefighters exceeded exposure limits. Median personal air concentrations of HCN (16,300 ppb) exceeded the exposure limit for outside vent firefighters, with maximum levels (72,900 ppb) higher than the immediately dangerous to life and health (IDLH) level. Median air concentrations on the fireground (including particle count) were above background levels and highest when collected downwind of the structure and when ground-level smoke was the heaviest. No statistically significant differences in personal air concentrations were found between the 2 attack tactics. The results underscore the importance of wearing self-contained breathing apparatus when conducting overhaul or outside ventilation activities. Firefighters should also try to establish command upwind of the structure fire, and if this cannot be done, respiratory protection should be considered.

External benefits of biomass-e in Spain: an economic valuation.

PubMed

Soliño, Mario

2010-03-01

This article analyses the willingness to pay for a program that promotes the production of electricity from forest biomass, instead of that based on fossil fuels. The program decreases greenhouse gas emissions, reduces the pressure on non-renewable resources, lowers the risk of summer forest fires, creates employment in rural areas. Results from a choice experiment show that consumers are willing to pay a higher price for electricity in order to obtain the external benefits of the substitution. Respondents attach a higher value to programs that decrease the pressure of non-renewable resources and the risk of forest fires. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Modeling of exposure to carbon monoxide in fires

NASA Technical Reports Server (NTRS)

Cagliostro, D. E.

1980-01-01

A mathematical model is developed to predict carboxyhemoglobin concentrations in regions of the body for short exposures to carbon monoxide levels expected during escape from aircraft fires. The model includes the respiratory and circulatory dynamics of absorption and distribution of carbon monoxide and carboxyhemoglobin. Predictions of carboxyhemoglobin concentrations are compared to experimental values obtained for human exposures to constant high carbon monoxide levels. Predictions are within 20% of experimental values. For short exposure times, transient concentration effects are predicted. The effect of stress is studied and found to increase carboxyhemoglobin levels substantially compared to a rest state.

Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

PubMed Central

Saito, Atsushi; Takahashi, Masayuki; Makino, Kei; Suzuki, Yukihisa; Jimbo, Yasuhiko; Nakasono, Satoshi

2018-01-01

High-intensity and low frequency (1–100 kHz) time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz), a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF), and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA)-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms), 50 Hz, sinusoidal wave, 6 s), the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI); subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field) in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that the potentiation of neuronal activity after 400 mT hPF-MF exposure was related to the depression of autonomous activity of pacemaker-like neurons. Our results indicated that the synchronized bursting activity was increased by hPF-MF exposure (E-field: >0.3 V/m), and the response was due to reduced inhibitory pacemaker-like neuronal activity. PMID:29662453

Network analysis of wildfire transmission and implications for risk governance

PubMed Central

Ager, Alan A.; Evers, Cody R.; Day, Michelle A.; Preisler, Haiganoush K.; Barros, Ana M. G.; Nielsen-Pincus, Max

2017-01-01

We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon US. Wildfire simulation and network analysis were used to quantify the exchange of fire among land tenures and communities and analyze the relative contributions of human versus natural ignitions to wildfire exposure. Among the land tenures examined, the area burned by incoming fires averaged 57% of the total burned area. Community exposure from incoming fires ignited on surrounding land tenures accounted for 67% of the total area burned. The number of land tenures contributing wildfire to individual communities and surrounding wildland urban interface (WUI) varied from 3 to 20. Community firesheds, i.e. the area where ignitions can spawn fires that can burn into the WUI, covered 40% of the landscape, and were 5.5 times larger than the combined area of the community core and WUI. For the major land tenures within the study area, the amount of incoming versus outgoing fire was relatively constant, with some exceptions. The study provides a multi-scale characterization of wildfire networks within a large, mixed tenure and fire prone landscape, and illustrates the connectivity of risk between communities and the surrounding wildlands. We use the findings to discuss how scale mismatches in local wildfire governance result from disconnected planning systems and disparate fire management objectives among the large landowners (federal, state, private) and local communities. Local and regional risk planning processes can adopt our concepts and methods to better define and map the scale of wildfire risk from large fire events and incorporate wildfire network and connectivity concepts into risk assessments. PMID:28257416

Network analysis of wildfire transmission and implications for risk governance.

PubMed

Ager, Alan A; Evers, Cody R; Day, Michelle A; Preisler, Haiganoush K; Barros, Ana M G; Nielsen-Pincus, Max

2017-01-01

We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon US. Wildfire simulation and network analysis were used to quantify the exchange of fire among land tenures and communities and analyze the relative contributions of human versus natural ignitions to wildfire exposure. Among the land tenures examined, the area burned by incoming fires averaged 57% of the total burned area. Community exposure from incoming fires ignited on surrounding land tenures accounted for 67% of the total area burned. The number of land tenures contributing wildfire to individual communities and surrounding wildland urban interface (WUI) varied from 3 to 20. Community firesheds, i.e. the area where ignitions can spawn fires that can burn into the WUI, covered 40% of the landscape, and were 5.5 times larger than the combined area of the community core and WUI. For the major land tenures within the study area, the amount of incoming versus outgoing fire was relatively constant, with some exceptions. The study provides a multi-scale characterization of wildfire networks within a large, mixed tenure and fire prone landscape, and illustrates the connectivity of risk between communities and the surrounding wildlands. We use the findings to discuss how scale mismatches in local wildfire governance result from disconnected planning systems and disparate fire management objectives among the large landowners (federal, state, private) and local communities. Local and regional risk planning processes can adopt our concepts and methods to better define and map the scale of wildfire risk from large fire events and incorporate wildfire network and connectivity concepts into risk assessments.

The consequences of lifetime and evolutionary exposure to toxic prey: changes in avoidance behaviour through ontogeny.

PubMed

Robbins, T R; Langkilde, T

2012-10-01

Responses to novel threats (e.g. invasive species) can involve genetic changes or plastic shifts in phenotype. There is controversy over the relative importance of these processes for species survival of such perturbations, but we are realizing they are not mutually exclusive. Native eastern fence lizards (Sceloporus undulatus) have adapted to top-down predation pressure imposed by the invasive red imported fire ant (Solenopsis invicta) via changes in adult (but not juvenile) lizard antipredator behaviour. Here, we examine the largely ignored, but potentially equally important, bottom-up effect of fire ants as toxic prey for lizards. We test how fire ant consumption (or avoidance) is affected by lifetime (via plasticity) and evolutionary (via natural selection) exposure to fire ants by comparing field-caught and laboratory-reared lizards, respectively, from fire ant-invaded and uninvaded populations. More naive juveniles from invaded populations ate fire ants than did adults, reflecting a natural ontogenetic dietary shift away from ants. Laboratory-reared lizards from the invaded site were less likely to eat fire ants than were those from the uninvaded site, suggesting a potential evolutionary shift in feeding behaviour. Lifetime and evolutionary exposure interacted across ontogeny, however, and field-caught lizards from the invaded site exhibited opposite ontogenetic trends; adults were more likely to eat fire ants than were juveniles. Our results suggest that plastic and evolutionary processes may both play important roles in permitting species survival of novel threats. We further reveal how complex interactions can shape adaptive responses to multimodal impacts imposed by invaders: in our system, fire ants impose stronger bottom-up selection than top-down selection, with each selection regime changing differently across lizard ontogeny. © 2012 The Authors. Journal of Evolutionary Biology © 2012 European Society For Evolutionary Biology.

Assessment of Ambient Exposures Firefighters Encounter While at the Fire Station: An Exploratory Study.

PubMed

Sparer, Emily H; Prendergast, Daniel P; Apell, Jennifer N; Bartzak, Madeleine R; Wagner, Gregory R; Adamkiewicz, Gary; Hart, Jaime E; Sorensen, Glorian

2017-10-01

Firefighters are at an increased risk for many types of cancer. Although most studies on this topic focus on exposures encountered while fighting fires, exposures at the fire station are also cause for concern. This pilot study aimed to describe air quality within a few fire stations in and around Boston, Massachusetts, and to investigate physical and organizational factors that may influence levels of contaminants in stations. Air sampling of particulate matter less than 2.5 μm in diameter (PM2.5) and particle-bound polycyclic aromatic hydrocarbons (PAHs) was completed at four fire stations in Spring, 2016. Sampling occurred in the kitchen, truck bay, and just outside the station. Data were analyzed to assess differences between and within stations. Interviews (n =7) were conducted with officers at each station to explore health and safety-related organizational policies and practices. Interviews were transcribed and analyzed for thematic content. At each station, levels of contaminants were higher in the truck bays than either the outdoors or kitchen, and varied the most throughout the day. The station with the highest exposures in the truck bay had the lowest levels in the kitchen, which was possibly explained by new building materials and effective separation between building zones. The age and layout of the stations appeared to determine the extent to which policies favoring exhaust capture were implemented. Levels of PM2.5 and PAH inside fire stations may contribute to firefighter cancer risk. Through understanding contaminant variability, we can begin to design and test interventions that improve cancer prevention.

Noise Exposure on a Warship during Firing of a Heavy Machine Gun.

PubMed

Paddan, Gurmail S

2015-11-01

Sound pressure levels were measured on a military ship during firing of a Heavy Machine Gun (HMG). Measurements were made at three locations on the ship's bridge (the wheelhouse) and one location on the starboard bridge wing. The highest peak sound pressure levels measured on the bridge wing and on the bridge were 160.7 dB(C) (2170 Pa) and 122.7 dB(C) (27.3 Pa), respectively. The highest sound exposure levels measured on the bridge wing and on the bridge corresponding to one round being fired were 127.8 dB(A) and 88.9 dB(A), respectively. The ship's structure provided about 40 dB attenuation in the transmitted noise. The operator of the weapon would be required to wear some form of hearing protection. Based on the measured peak noise levels, there would be no requirement for bridge crew to wear any hearing protection during firing of a HMG. However, crew exposure to noise on the bridge is likely to exceed the upper exposure action value corresponding to 85 dB(A) after about 11 750 rounds. © The Author 2015. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

The Significance of Fire Service Culture as an Impediment to Effective Leadership in the Homeland Security Environment

DTIC Science & Technology

2012-03-01

somehow poignantly related to the topic at hand. Whether through charm, wit, or emotion, Brunacini knew how to get his desired messages across to his...2006, p. 9). 74 With such an overtly confident perspective we may begin to understand how firefighters may get themselves into trouble on the fire...elements epitomized by fire service culture. It then examines how both internal and external sociological factors contribute to the perpetuation of

Factor information retrieval system version 2. 0 (fire) (for microcomputers). Software

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

Not Available

FIRE Version 2.0 contains EPA's unique recommended criteria and toxic air emission estimation factors. FIRE consists of: (1) an EPA internal repository system that contains emission factor data identified and collected, and (2) an external distribution system that contains only EPA's recommended factors. The emission factors, compiled from a review of the literature, are identified by pollutant name, CAS number, process and emission source descriptions, SIC code, SCC, and control status. The factors are rated for quality using AP-42 rating criteria.

Exposure to fire setting behavior on YouTube.

PubMed

Thomas, Meara; Mackay, Sherri; Salsbury, Debbie

2012-07-01

This study is a preliminary examination of fire setting behaviors on YouTube. Data are based on a 1 day search of YouTube. Results indicate YouTube is replete with inappropriate models of fire setting. The findings have potential implications for intervention with fire setting youth. Copyright © 2012 Society for Adolescent Health and Medicine. Published by Elsevier Inc. All rights reserved.

Respiratory Symptoms Following Wildfire Smoke Exposure

PubMed Central

Mirabelli, Maria C.; Künzli, Nino; Avol, Edward; Gilliland, Frank D.; Gauderman, W. James; McConnell, Rob; Peters, John M.

2015-01-01

Background Associations between exposure to smoke during wild-fire events and respiratory symptoms are well documented, but the role of airway size remains unclear. We conducted this analysis to assess whether small airway size modifies these relationships. Methods We analyzed data from 465 nonasthmatic 16- to 19-year-old participants in the Children’s Health Study. Following an outbreak of wildfires in 2003, each student completed a questionnaire about smoke exposure, dry and wet cough, wheezing, and eye symptoms. We used log-binomial regression to evaluate associations between smoke exposure and fire-related health symptoms, and to assess modification of the associations by airway size. As a marker of airway size, we used the ratio of maximum midexpiratory flow to forced vital capacity. Results Forty percent (186 of 465) of this population (including students from 11 of 12 surveyed communities) reported the odor of wildfire smoke at home. We observed increased respiratory and eye symptoms with increasing frequency of wildfire smoke exposure. Associations between smoke exposure and having any of 4 respiratory symptoms were stronger in the lowest quartile of the lung function ratio (eg, fire smoke 6+ days: prevalence ratio: 3.8; 95% confidence interval (CI = 2.0 –7.2), compared with the remaining quartiles (fire smoke 6+ days: prevalence ratio = 2.0; 1.2–3.2). Analysis of individual symptoms suggests that this interaction may be strongest for effects on wheezing. Conclusions Small airways may serve as a marker of susceptibility to effects of wildfire smoke. Future studies should investigate the role of airway size for more common exposures and should include persons with asthma. PMID:19276978

Absence of Visual Input Results in the Disruption of Grid Cell Firing in the Mouse.

PubMed

Chen, Guifen; Manson, Daniel; Cacucci, Francesca; Wills, Thomas Joseph

2016-09-12

Grid cells are spatially modulated neurons within the medial entorhinal cortex whose firing fields are arranged at the vertices of tessellating equilateral triangles [1]. The exquisite periodicity of their firing has led to the suggestion that they represent a path integration signal, tracking the organism's position by integrating speed and direction of movement [2-10]. External sensory inputs are required to reset any errors that the path integrator would inevitably accumulate. Here we probe the nature of the external sensory inputs required to sustain grid firing, by recording grid cells as mice explore familiar environments in complete darkness. The absence of visual cues results in a significant disruption of grid cell firing patterns, even when the quality of the directional information provided by head direction cells is largely preserved. Darkness alters the expression of velocity signaling within the entorhinal cortex, with changes evident in grid cell firing rate and the local field potential theta frequency. Short-term (<1.5 s) spike timing relationships between grid cell pairs are preserved in the dark, indicating that network patterns of excitatory and inhibitory coupling between grid cells exist independently of visual input and of spatially periodic firing. However, we find no evidence of preserved hexagonal symmetry in the spatial firing of single grid cells at comparable short timescales. Taken together, these results demonstrate that visual input is required to sustain grid cell periodicity and stability in mice and suggest that grid cells in mice cannot perform accurate path integration in the absence of reliable visual cues. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.

Exploring Use of Climate Information in Wildland Fire Management: A Decision Calendar Study

Treesearch

Thomas W. Corringham; Anthony L. Westerling; Barbara J. Morehouse

2006-01-01

Wildfire management is an institutionally complex process involving a complex budget and appropriations cycle, a variety of objectives, and a set of internal and external political constraints. Significant potential exists for enhancing the use of climate information and long-range climate forecasts in wildland fire management in the Western U.S. Written surveys and...

Ignition and flame-growth modeling on realistic building and landscape objects in changing environments

Treesearch

Mark A. Dietenberger

2010-01-01

Effective mitigation of external fires on structures can be achieved flexibly, economically, and aesthetically by (1) preventing large-area ignition on structures by avoiding close proximity of burning vegetation; and (2) stopping flame travel from firebrands landing on combustible building objects. Using bench-scale and mid-scale fire tests to obtain flammability...

Examining fire-prone forest landscapes as coupled human and natural systems

Treesearch

Thomas A. Spies; Eric M. White; Jeffrey D. Kline; A. Paige Fisher; Alan Ager; John Bailey; John Bolte; Jennifer Koch; Emily Platt; Christine S. Olsen; Derric Jacobs; Bruce Shindler; Michelle M. Steen-Adams; Roger Hammer

2014-01-01

Fire-prone landscapes are not well studied as coupled human and natural systems (CHANS) and present many challenges for understanding and promoting adaptive behaviors and institutions. Here, we explore how heterogeneity, feedbacks, and external drivers in this type of natural hazard system can lead to complexity and can limit the development of more adaptive approaches...

Protect Thy Neighbor: Investigating the Spatial Externalities of Community Wildfire Hazard Mitigation

Treesearch

David Butry; Geoffrey Donovan

2008-01-01

Climate change, increased wildland fuels, and residential development patterns in fire-prone areas all combine to make wildfire risk mitigation an important public policy issue. One approach to wildfire risk mitigation is to encourage homeowners to use fire-resistant building materials and to create defensible spaces around their homes. We develop a theoretical model...

An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios (External Review Draft)

EPA Science Inventory

EPA has released an external review draft entitled, An Exploratory Study: Assessment of Modeled Dioxin Exposure in Ceramic Art Studios(External Review Draft). The public comment period and the external peer-review workshop are separate processes that provide opportunities ...

Computational modeling of blast exposure associated with recoilless weapons combat training

NASA Astrophysics Data System (ADS)

Wiri, S.; Ritter, A. C.; Bailie, J. M.; Needham, C.; Duckworth, J. L.

2017-11-01

Military personnel are exposed to blast as part of routine combat training with shoulder-fired recoilless rifles. These weapons fire large-caliber ammunitions capable of disabling structures and uparmored vehicles (e.g., tanks). Scientific, medical, and military leaders are beginning to recognize the blast overpressure from these shoulder-fired weapons may result in acute and even long-term physiological effects to military personnel. However, the back blast generated from the Carl Gustav and Shoulder-launched Multipurpose Assault Weapon (SMAW) shoulder-fired weapons on the weapon operator has not been quantified. By quantifying and modeling the full-body blast exposure from these weapons, better injury correlations can be constructed. Blast exposure data from the Carl Gustav and SMAW were used to calibrate a propellant burn source term for computational simulations of blast exposure on operators of these shoulder-mounted weapon systems. A propellant burn model provided the source term for each weapon to capture blast effects. Blast data from personnel-mounted gauges during weapon firing were used to create initial, high-fidelity 3D computational fluid dynamic simulations using SHAMRC (Second-order Hydrodynamic Automatic Mesh Refinement Code). These models were then improved upon using data collected from static blast sensors positioned around the military personnel while weapons were utilized in actual combat training. The final simulation models for both the Carl Gustav and SMAW were in good agreement with the data collected from the personnel-mounted and static pressure gauges. Using the final simulation results, contour maps were created for peak overpressure and peak overpressure impulse experienced by military personnel firing the weapon as well as those assisting with firing of those weapons. Reconstruction of the full-body blast loading enables a more accurate assessment of the cause of potential mechanisms of injury due to air blast even for subjects not wearing blast gauges themselves. By accurately understanding the blast exposure and its variations across an individual, more meaningful correlations with physiologic response including potential TBI spectrum physiology associated with sub-concussive blast exposure can be established. As blast injury thresholds become better defined, results from these reconstructions can provide important insights into approaches for reducing possible risk of injury to personnel operating shoulder-launched weapons.

Toxicity of PHOS-CHEK LC-95A and 259F fire retardants to ocean- and stream-type Chinook salmon and their potential to recover before seawater entry.

PubMed

Dietrich, Joseph P; Van Gaest, Ahna L; Strickland, Stacy A; Hutchinson, Greg P; Krupkin, Alex B; Arkoosh, Mary R

2014-08-15

Long-term fire retardants are used to prevent the spread of wildland fire, but have inadvertently entered aquatic habitats and resulted in fish kills. We examined the toxicity of two fire retardant products; PHOS-CHEK 259F and LC-95A, on Chinook salmon with two different life histories, ocean-type and stream-type, at different stages of their development. Ocean-type Chinook outmigrate to the ocean as subyearlings; while, stream-type salmon overwinter in freshwater and outmigrate as yearlings. Ocean-type and stream-type salmon were exposed to the fire retardants prior to their parr to smolt transition (presmolts) as subyearlings (stream-type and ocean-type) and yearlings (stream-type only), as well as during their transition (smolts). The salmon were exposed to eight concentrations of each retardant and a control for 96h to determine acute toxicity. Lethal concentration curves were modeled by logistic regression for each life history and life stage exposed to the two fire retardants. Among all life histories and life stages tested, PHOS-CHEK 259F was most toxic to stream-type salmon at smolt stage and PHOS-CHEK LC-95A was most toxic to ocean-type salmon at smolt stage. To determine the delayed effects of product exposures on fish health as well as for the potential of recovery, 24-hour seawater challenges were performed immediately after fire retardant exposure, as well as after a recovery period. Previous PHOS-CHEK exposure reduced survival during seawater challenge among salmon from both life histories undergoing the parr-smolt transition and was more pronounced after PHOS-CHEK LC-95A exposure. However, this delayed effect was not observed 34 or more days after either PHOS-CHEK exposure. We conclude that accidental PHOS-CHEK LC-95A or 259F drops during salmon outmigration would have adverse impacts that extend beyond the acute mortality that occurs within the immediate drop and dilution areas. Published by Elsevier B.V.

Seeing through the Smoke: A collaborative, multidisciplinary effort to address the interplay between wildfire, climate, air quality, and health

NASA Astrophysics Data System (ADS)

Brey, S. J.; Fischer, E. V.; Pierce, J. R.; Ford, B.; Lassman, W.; Pfister, G.; Volckens, J.; Gan, R.; Magzamen, S.; Barnes, E. A.

2015-12-01

Exposure to wildfire smoke plumes represents an episodic, uncertain, and potentially growing threat to public health in the western United States. The area burned by wildfires in this region has increased over recent decades, and the future of fires within this region is largely unknown. Future fire emissions are intimately linked to future meteorological conditions, which are uncertain due to the variability of climate model outputs and differences between representative concentration pathways (RCP) scenarios. We know that exposure to wildfire smoke is harmful, particularly for vulnerable populations. However the literature on the heath effects of wildfire smoke exposure is thin, particularly when compared to the depth of information we have on the effects of exposure to smoke of anthropogenic origin. We are exploring the relationships between climate, fires, air quality and public health through multiple interdisciplinary collaborations. We will present several examples from these projects including 1) an analysis of the influence of fire on ozone abundances over the United States, and 2) efforts to use a high-resolution weather forecasting model to nail down exposure within specific smoke plumes. We will also highlight how our team works together. This discussion will include examples of the university structure that facilitates our current collaborations, and the lessons we have learned by seeking stakeholder input to make our science more useful.

An empirical model to estimate daily forest fire smoke exposure over a large geographic area using air quality, meteorological, and remote sensing data

PubMed Central

Yao, Jiayun; Henderson, Sarah B

2014-01-01

Exposure to forest fire smoke (FFS) is associated with a range of adverse health effects. The British Columbia Asthma Medication Surveillance (BCAMS) product was developed to detect potential impacts from FFS in British Columbia (BC), Canada. However, it has been a challenge to estimate FFS exposure with sufficient spatial coverage for the provincial population. We constructed an empirical model to estimate FFS-related fine particulate matter (PM2.5) for all populated areas of BC using data from the most extreme FFS days in 2003 through 2012. The input data included PM2.5 measurements on the previous day, remotely sensed aerosols, remotely sensed fires, hand-drawn tracings of smoke plumes from satellite images, fire danger ratings, and the atmospheric venting index. The final model explained 71% of the variance in PM2.5 observations. Model performance was tested in days with high, moderate, and low levels of FFS, resulting in correlations from 0.57 to 0.83. We also developed a method to assign the model estimates to geographical local health areas for use in BCAMS. The simplicity of the model allows easy application in time-constrained public health surveillance, and its sufficient spatial coverage suggests utility as an exposure assessment tool for epidemiologic studies on FFS exposure. PMID:24301352

Assessing Landscape Scale Wildfire Exposure for Highly Valued Resources in a Mediterranean Area

NASA Astrophysics Data System (ADS)

Alcasena, Fermín J.; Salis, Michele; Ager, Alan A.; Arca, Bachisio; Molina, Domingo; Spano, Donatella

2015-05-01

We used a fire simulation modeling approach to assess landscape scale wildfire exposure for highly valued resources and assets (HVR) on a fire-prone area of 680 km2 located in central Sardinia, Italy. The study area was affected by several wildfires in the last half century: some large and intense fire events threatened wildland urban interfaces as well as other socioeconomic and cultural values. Historical wildfire and weather data were used to inform wildfire simulations, which were based on the minimum travel time algorithm as implemented in FlamMap. We simulated 90,000 fires that replicated recent large fire events in the area spreading under severe weather conditions to generate detailed maps of wildfire likelihood and intensity. Then, we linked fire modeling outputs to a geospatial risk assessment framework focusing on buffer areas around HVR. The results highlighted a large variation in burn probability and fire intensity in the vicinity of HVRs, and allowed us to identify the areas most exposed to wildfires and thus to a higher potential damage. Fire intensity in the HVR buffers was mainly related to fuel types, while wind direction, topographic features, and historically based ignition pattern were the key factors affecting fire likelihood. The methodology presented in this work can have numerous applications, in the study area and elsewhere, particularly to address and inform fire risk management, landscape planning and people safety on the vicinity of HVRs.

Real time chemical exposure and risk monitor

DOEpatents

Thrall, Karla D.; Kenny, Donald V.; Endres, George W. R.; Sisk, Daniel R.

1997-01-01

The apparatus of the present invention is a combination of a breath interface and an external exposure dosimeter interface to a chemical analysis device, all controlled by an electronic processor for quantitatively analyzing chemical analysis data from both the breath interface and the external exposure dosimeter for determining internal tissue dose. The method of the present invention is a combination of steps of measuring an external dose, measuring breath content, then analyzing the external dose and breath content and determining internal tissue dose.

Real time chemical exposure and risk monitor

DOEpatents

Thrall, K.D.; Kenny, D.V.; Endres, G.W.R.; Sisk, D.R.

1997-07-08

The apparatus of the present invention is a combination of a breath interface and an external exposure dosimeter interface to a chemical analysis device, all controlled by an electronic processor for quantitatively analyzing chemical analysis data from both the breath interface and the external exposure dosimeter for determining internal tissue dose. The method of the present invention is a combination of steps of measuring an external dose, measuring breath content, then analyzing the external dose and breath content and determining internal tissue dose. 7 figs.

Systemic exposure to PAHs and benzene in firefighters suppressing controlled structure fires.

PubMed

Fent, Kenneth W; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D; Stiegel, Matthew A; Mueller, Charles; Horn, Gavin P; Dalton, James

2014-08-01

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters' bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants. © The Author 2014. Published by Oxford University Press on behalf of the British Occupational Hygiene Society.

Systemic Exposure to PAHs and Benzene in Firefighters Suppressing Controlled Structure Fires

PubMed Central

Fent, Kenneth W.; Eisenberg, Judith; Snawder, John; Sammons, Deborah; Pleil, Joachim D.; Stiegel, Matthew A.; Mueller, Charles; Horn, Gavin P.; Dalton, James

2014-01-01

Turnout gear provides protection against dermal exposure to contaminants during firefighting; however, the level of protection is unknown. We explored the dermal contribution to the systemic dose of polycyclic aromatic hydrocarbons (PAHs) and other aromatic hydrocarbons in firefighters during suppression and overhaul of controlled structure burns. The study was organized into two rounds, three controlled burns per round, and five firefighters per burn. The firefighters wore new or laundered turnout gear tested before each burn to ensure lack of PAH contamination. To ensure that any increase in systemic PAH levels after the burn was the result of dermal rather than inhalation exposure, the firefighters did not remove their self-contained breathing apparatus until overhaul was completed and they were >30 m upwind from the burn structure. Specimens were collected before and at intervals after the burn for biomarker analysis. Urine was analyzed for phenanthrene equivalents using enzyme-linked immunosorbent assay and a benzene metabolite (s-phenylmercapturic acid) using liquid chromatography/tandem mass spectrometry; both were adjusted by creatinine. Exhaled breath collected on thermal desorption tubes was analyzed for PAHs and other aromatic hydrocarbons using gas chromatography/mass spectrometry. We collected personal air samples during the burn and skin wipe samples (corn oil medium) on several body sites before and after the burn. The air and wipe samples were analyzed for PAHs using a liquid chromatography with photodiode array detection. We explored possible changes in external exposures or biomarkers over time and the relationships between these variables using non-parametric sign tests and Spearman tests, respectively. We found significantly elevated (P < 0.05) post-exposure breath concentrations of benzene compared with pre-exposure concentrations for both rounds. We also found significantly elevated post-exposure levels of PAHs on the neck compared with pre-exposure levels for round 1. We found statistically significant positive correlations between external exposures (i.e. personal air concentrations of PAHs) and biomarkers (i.e. change in urinary PAH metabolite levels in round 1 and change in breath concentrations of benzene in round 2). The results suggest that firefighters wearing full protective ensembles absorbed combustion products into their bodies. The PAHs most likely entered firefighters’ bodies through their skin, with the neck being the primary site of exposure and absorption due to the lower level of dermal protection afforded by hoods. Aromatic hydrocarbons could have been absorbed dermally during firefighting or inhaled during the doffing of gear that was off-gassing contaminants. PMID:24906357

Fire development and wall endurance in sandwich and wood-frame structures

Treesearch

Carlton A. Holmes; Herbert W. Eickner; John J. Brenden; Curtis C. Peters; Robert H. White

1980-01-01

Large-scale fire tests were conducted on seven 16- by 24-foot structures. Four of these structures were of sandwich construction with cores of plastic or paper honeycomb and three were of wood-frame construction. The wasss were loaded to a computer design loading, and the fire endurance determined under a fire exposure from a typical building contents loading of 4-1/2...

EcoSmart Fire as structure ignition model in wildland urban interface: predictions and validations

Treesearch

Mark A. Dietenberger; Charles R. Boardman

2016-01-01

EcoSmartFire is a Windows program that models heat damage and piloted ignition of structures from radiant exposure to discrete landscaped tree fires. It calculates the radiant heat transfer from cylindrical shaped fires to the walls and roof of the structure while accounting for radiation shadowing, attenuation, and ground reflections. Tests of litter burn, a 0.6 m...

Main Propulsion Test Article (MPTA)

NASA Technical Reports Server (NTRS)

Snoddy, Cynthia

2010-01-01

Scope: The Main Propulsion Test Article integrated the main propulsion subsystem with the clustered Space Shuttle Main Engines, the External Tank and associated GSE. The test program consisted of cryogenic tanking tests and short- and long duration static firings including gimbaling and throttling. The test program was conducted on the S1-C test stand (Position B-2) at the National Space Technology Laboratories (NSTL)/Stennis Space Center. 3 tanking tests and 20 hot fire tests conducted between December 21 1 1977 and December 17, 1980 Configuration: The main propulsion test article consisted of the three space shuttle main engines, flightweight external tank, flightweight aft fuselage, interface section and a boilerplate mid/fwd fuselage truss structure.

A Forest Fire Sensor Web Concept with UAVSAR

NASA Astrophysics Data System (ADS)

Lou, Y.; Chien, S.; Clark, D.; Doubleday, J.; Muellerschoen, R.; Zheng, Y.

2008-12-01

We developed a forest fire sensor web concept with a UAVSAR-based smart sensor and onboard automated response capability that will allow us to monitor fire progression based on coarse initial information provided by an external source. This autonomous disturbance detection and monitoring system combines the unique capabilities of imaging radar with high throughput onboard processing technology and onboard automated response capability based on specific science algorithms. In this forest fire sensor web scenario, a fire is initially located by MODIS/RapidFire or a ground-based fire observer. This information is transmitted to the UAVSAR onboard automated response system (CASPER). CASPER generates a flight plan to cover the alerted fire area and executes the flight plan. The onboard processor generates the fuel load map from raw radar data, used with wind and elevation information, predicts the likely fire progression. CASPER then autonomously alters the flight plan to track the fire progression, providing this information to the fire fighting team on the ground. We can also relay the precise fire location to other remote sensing assets with autonomous response capability such as Earth Observation-1 (EO-1)'s hyper-spectral imager to acquire the fire data.

The importance of considering external influences during presuppression wildfire planning

Treesearch

Marc R. Wiitala; Andrew E. Wilson

2008-01-01

Few administrative units involved in wildland fire protection are islands unto themselves when it comes to wildfire activity and suppression. If not directly affected by the wildfire workload of their neighbors, they are affected by the availability of nationally shared resources impacted by wildfire activity at the regional and national scale. These external...

Analyzing seasonal patterns of wildfire exposure factors in Sardinia, Italy.

PubMed

Salis, Michele; Ager, Alan A; Alcasena, Fermin J; Arca, Bachisio; Finney, Mark A; Pellizzaro, Grazia; Spano, Donatella

2015-01-01

In this paper, we applied landscape scale wildfire simulation modeling to explore the spatiotemporal patterns of wildfire likelihood and intensity in the island of Sardinia (Italy). We also performed wildfire exposure analysis for selected highly valued resources on the island to identify areas characterized by high risk. We observed substantial variation in burn probability, fire size, and flame length among time periods within the fire season, which starts in early June and ends in late September. Peak burn probability and flame length were observed in late July. We found that patterns of wildfire likelihood and intensity were mainly related to spatiotemporal variation in ignition locations, fuel moisture, and wind vectors. Our modeling approach allowed consideration of historical patterns of winds, ignition locations, and live and dead fuel moisture on fire exposure factors. The methodology proposed can be useful for analyzing potential wildfire risk and effects at landscape scale, evaluating historical changes and future trends in wildfire exposure, as well as for addressing and informing fuel management and risk mitigation issues.

Exposure to an Indoor Cooking Fire and Risk of Trachoma in Children of Kongwa, Tanzania

PubMed Central

Zambrano, Andrea I.; Muñoz, Beatriz E.; Mkocha, Harran; West, Sheila K.

2015-01-01

Background Elimination of blinding trachoma by 2020 can only be achieved if affected areas have effective control programs in place before the target date. Identifying risk factors for active disease that are amenable to intervention is important to successfully design such programs. Previous studies have linked sleeping by a cooking fire to trachoma in children, but not fully explored the mechanism and risks. We propose to determine the risk for active trachoma in children with exposure to cooking fires by severity of trachoma, adjusting for other known risk factors. Methods Complete census of 52 communities in Kongwa, Tanzania, was conducted to collect basic household characteristics and demographic information on each family member. Information on exposure to indoor cooking fires while the mother was cooking and while sleeping for each child was collected. 6656 randomly selected children ages 1-9yrs were invited to a survey where both eyelids were graded for follicular (TF) and intense trachoma (TI) using the WHO simplified grading scheme. Ocular swab were taken to assess the presence of Chlamydia trachomatis. Findings 5240 (79%) of the invited children participated in the study. Overall prevalence for trachoma was 6·1%. Odds for trachoma and increased severity were higher in children sleeping without ventilation and a cooking fire in their room (TF OR = 1·81, 1·00–3·27 and TI OR 4·06, 1·96–8·42). Children with TF or TI who were exposed were more likely to have infection than children with TF or TI who were not exposed. There was no increased risk with exposure to a cooking fire while the mother was cooking. Conclusions In addition to known risk factors for trachoma, sleeping by an indoor cooking fire in a room without ventilation was associated with active trachoma and appears to substantially increase the risk of intense inflammation. PMID:26046359

Exposure to an Indoor Cooking Fire and Risk of Trachoma in Children of Kongwa, Tanzania.

PubMed

Zambrano, Andrea I; Muñoz, Beatriz E; Mkocha, Harran; West, Sheila K

2015-01-01

Elimination of blinding trachoma by 2020 can only be achieved if affected areas have effective control programs in place before the target date. Identifying risk factors for active disease that are amenable to intervention is important to successfully design such programs. Previous studies have linked sleeping by a cooking fire to trachoma in children, but not fully explored the mechanism and risks. We propose to determine the risk for active trachoma in children with exposure to cooking fires by severity of trachoma, adjusting for other known risk factors. Complete census of 52 communities in Kongwa, Tanzania, was conducted to collect basic household characteristics and demographic information on each family member. Information on exposure to indoor cooking fires while the mother was cooking and while sleeping for each child was collected. 6656 randomly selected children ages 1-9 yrs were invited to a survey where both eyelids were graded for follicular (TF) and intense trachoma (TI) using the WHO simplified grading scheme. Ocular swab were taken to assess the presence of Chlamydia trachomatis. 5240 (79%) of the invited children participated in the study. Overall prevalence for trachoma was 6·1%. Odds for trachoma and increased severity were higher in children sleeping without ventilation and a cooking fire in their room (TF OR = 1·81, 1·00-3·27 and TI OR 4·06, 1·96-8·42). Children with TF or TI who were exposed were more likely to have infection than children with TF or TI who were not exposed. There was no increased risk with exposure to a cooking fire while the mother was cooking. In addition to known risk factors for trachoma, sleeping by an indoor cooking fire in a room without ventilation was associated with active trachoma and appears to substantially increase the risk of intense inflammation.

Quantification of the volatile organic compounds in the smoke from prescribed burning and comparison with the occupational exposure limits

NASA Astrophysics Data System (ADS)

Barboni, T.; Santoni, P.-A.

2013-11-01

Prescribed burning represents a serious threat to the personnel fighting fires because of smoke inhalation. This study aims to increase the knowledge about foresters exposure to the prescribed burning smoke by focusing on exposure to volatile organic compounds (VOCs). We initially assessed the methodology for smoke sampling. Then, we identified potentially dangerous molecules among the VOCs identified at 4 prescribed burning sites located around Corsica. The values measured were very high, exceeding the exposure limits, particularly for benzene, phenol, and furfural, whose concentrations were above short-term exposure limit (STEL) values. In conclusion, obvious but necessary recommendations were made for the protection of the personnel involved in fighting fires on a professional basis.

Role of Direct and Indirect Violence Exposure on Externalizing Behavior in Children.

PubMed

Fleckman, Julia M; Drury, Stacy S; Taylor, Catherine A; Theall, Katherine P

2016-06-01

The objective of this study was to examine the association between externalizing behaviors and indirect violence exposure, assessed both within the household and at the community level, as well as the interaction effect of indirect and direct violence exposure. A sample of parents of children ages 4-15 who have not been referred or enrolled in child welfare (n = 82) were recruited from the greater New Orleans community. Externalizing behavior was assessed with the Child Behavior Checklist (CBCL). The child's indirect exposure to violence included witnessing community violence, witnessing physical assault, and witnessing fighting or domestic violence at home. Direct exposure to violence included the child experiencing physical aggression from a caregiver. All assessments were based on caregiver reports. To decrease potential for confounding, children were matched for analysis based on age, Hurricane Katrina exposure, and their propensity to be exposed to high indirect violence. Cumulative indirect exposure to violence was significantly positively correlated with CBCL scores. After controlling for key covariates, CBCL externalizing T score increased significantly by approximately 1.25 points for each level increase in indirect violence exposure (β = 1.25, SE = 0.57, p = 0.027). There also was a significant interaction between indirect and direct exposure to violence in the association with CBCL score (β = -0.08, SE = 0.03, p = 0.002). These findings extend previous research by demonstrating that exposure to both direct and cross-contextual indirect violence influences externalizing behaviors in children. Additionally, the findings suggest that community and household social environments are both important targets for interventions designed to decrease externalizing behaviors and improve long-term outcomes for youth at risk of exposure to violence.

Inhalation Injuries

MedlinePlus

... devastating types of trauma resulting from exposure to fire and smoke. PREVENT you and your loved ones! ... people die annually in the United States from fire injuries. • Over half of these deaths result from ...

Test results: Halon 1301 versus water sprinkler fire protection for essential electronic equipment

NASA Astrophysics Data System (ADS)

Reichelt, E. F.; Walker, J. L.; Vickers, R. N.; Kwan, A. J.

1982-07-01

This report describes results of testing two contending extinguishants, Halon 1301 and water, for fire protection of essential electronic equipment. A series of controlled fires in a facility housing an operational electronic data processing system sought to establish immediate and long term effects of exposure of sensitive electronic equipment and stored data to fire extinguishment atmospheres. Test results lead to the conclusion that Halon 1301 is superior to water as an extinguishant for fires occurring in essential electronic equipment installations.

Framework for addressing the national wildland urban interface fire problem—determining fire and ember exposure zones using a WUI hazard scale

Treesearch

Alexander Maranghides; William Mell

2012-01-01

Destruction of homes and businesses from Wildland Urban Interface (WUI) fires have been steadily escalating as have the fire suppression costs associated with them. Since 2000, in the U.S. over 3,000 homes per year are lost to WUI fires, compared to about 900 homes in the 1990s, and 400 homes in the 1970s. In 2011, in Texas alone, over 2,000 homes were...

Potential health impacts from range fires at Aberdeen Proving Ground, Maryland.

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

Willians, G.P.; Hermes, A.M.; Policastro, A.J.

1998-03-01

This study uses atmospheric dispersion computer models to evaluate the potential for human health impacts from exposure to contaminants that could be dispersed by fires on the testing ranges at Aberdeen Proving Ground, Maryland. It was designed as a screening study and does not estimate actual human health risks. Considered are five contaminants possibly present in the soil and vegetation from past human activities at APG--lead, arsenic, trichloroethylene (TCE), depleted uranium (DU), and dichlorodiphenyltrichloroethane (DDT); and two chemical warfare agents that could be released from unexploded ordnance rounds heated in a range fire--mustard and phosgene. For comparison, dispersion of twomore » naturally occurring compounds that could be released by burning of uncontaminated vegetation--vinyl acetate and 2-furaldehyde--is also examined. Data from previous studies on soil contamination at APG are used in conjunction with conservative estimates about plant uptake of contaminants, atmospheric conditions, and size and frequency of range fires at APG to estimate dispersion and possible human exposure. The results are compared with US Environmental Protection Agency action levels. The comparisons indicate that for all of the anthropogenic contaminants except arsenic and mustard, exposure levels would be at least an order of magnitude lower than the corresponding action levels. Because of the compoundingly conservative nature of the assumptions made, they conclude that the potential for significant human health risks from range fires is low. The authors recommend that future efforts be directed at fire management and control, rather than at conducting additional studies to more accurately estimate actual human health risk from range fires.« less

Individual external doses below the lowest reference level of 1 mSv per year five years after the 2011 Fukushima nuclear accident among all children in Soma City, Fukushima: A retrospective observational study.

PubMed

Tsubokura, Masaharu; Murakami, Michio; Nomura, Shuhei; Morita, Tomohiro; Nishikawa, Yoshitaka; Leppold, Claire; Kato, Shigeaki; Kami, Masahiro

2017-01-01

After the 2011 Fukushima Daiichi nuclear power plant accident, little information has been available on individual doses from external exposure among residents living in radioactively contaminated areas near the nuclear plant; in the present study we evaluated yearly changes in the doses from external exposure after the accident and the effects of decontamination on external exposure. This study considered all children less than 16 years of age in Soma City, Fukushima who participated in annual voluntary external exposure screening programs during the five years after the accident (n = 5,363). In total, 14,405 screening results were collected. The median participant age was eight years. The geometric mean levels of annual additional doses from external exposure attributable to the Fukushima accident, decreased each year: 0.60 mSv (range: not detectable (ND)-4.29 mSv), 0.37 mSv (range: ND-3.61 mSv), 0.22 mSv (range: ND-1.44 mSv), 0.20 mSv (range: ND-1.87 mSv), and 0.17 mSv (range: ND-0.85 mSv) in 2011, 2012, 2013, 2014, and 2015, respectively. The proportion of residents with annual additional doses from external exposure of more than 1 mSv dropped from 15.6% in 2011 to zero in 2015. Doses from external exposure decreased more rapidly than those estimated from only physical decay, even in areas without decontamination (which were halved in 395 days from November 15, 2011), presumably due to the weathering effects. While the ratios of geometric mean doses immediately after decontamination to before were slightly lower than those during the same time in areas without decontamination, annual additional doses reduced by decontamination were small (0.04-0.24 mSv in the year of immediately after decontamination was completed). The results of this study showed that the levels of external exposure among Soma residents less than 16 years of age decreased during the five years after the Fukushima Daiichi nuclear power plant accident. Decontamination had only limited and temporal effects on reducing individual external doses.

Different patterns of neuronal activities in the infralimbic and prelimbic cortices and behavioral expression in response to two affective odors, 2,5-dihydro-2,4,5-trimethylthiazoline and a mixture of cis-3-hexenol and trans-2-hexenal, in the freely moving rat.

PubMed

Nikaido, Y; Nakashima, T

2011-03-17

The medial prefrontal cortex (mPFC) is involved in stimulus perception, attentional control, emotional behavior, and the stress response. These functions are thought to be mediated by the infralimbic (IL) and prelimbic (PL) subregions of mPFC; however, few studies have examined the roles of IL and PL cortices in olfactory cognition. In the present study, we investigated the acute effects of two odors, 2,5-dihydro-2,4,5-trimethylthiazoline (TMT) and a mixture of cis-3-hexenol and trans-2-hexenal (green odor: GO), on behavioral responses and IL and PL neuronal activities using extracellular single-unit recordings in a freely moving rat. We found that the total number of spike firings in IL and PL neurons did not change with 10s presentation of odors. TMT presentation induced significant changes in burst firing activity in IL and PL neurons, while GO presentation induced changes in burst firing only in IL neurons. In the temporal profile of the firing activity of IL neurons, TMT exposure induced transient activation and GO exposure induced sustained activation. Those of PL neurons showed sustained activation during TMT exposure and transient activations during GO exposure. GO exposure induced a stretch-attend posture, whereas TMT exposure induced immobility. Furthermore, multiple regression analysis indicated that the property of the odor and neuronal activities of IL and PL regions were correlated with behavioral responses. These findings reveal that olfaction-related neurons exist in IL and PL regions, and that the neurons in these regions might temporarily encode odor information in order to modulate motor outputs by tuning firing properties in the early stage of cognition according to the odor property. Copyright © 2010 Elsevier B.V. All rights reserved.

Large-scale fiber release and equipment exposure experiments. [aircraft fires

NASA Technical Reports Server (NTRS)

Pride, R. A.

1980-01-01

Outdoor tests were conducted to determine the amount of fiber released in a full scale fire and trace its dissemination away from the fire. Equipment vulnerability to fire released fibers was assessed through shock tests. The greatest fiber release was observed in the shock tube where the composite was burned with a continuous agitation to total consumption. The largest average fiber length obtained outdoors was 5 mm.

A commercial application of fire retardants to dry-formed hardboards

Treesearch

Gary C. Meyers; Carlton A. Holmes

1977-01-01

Based on laboratory performance with a number of fire-retardant chemicals, disodium octaborate tetrahydrate-boric acid and dicyandiamide-phosphoric acid-formaldehyde were selected for treating fiber and making 4 foot by 8-foot dry-formed hardboards on a commercial production line. The boards were evaluated for performance under exposure to fire, strength, dimensional...

Limited direct effects of a massive wildfire on its sagebrush steppe bee community

USDA-ARS?s Scientific Manuscript database

Fire can affect bees directly, through exposure to heating and smoke during the combustion phase. Direct effects include mortality, injury and displacement affecting at most two generations of bees—adults and any progeny produced prior to the fire event. To study the direct effects of fire on a bee ...

What kind of cutting and thinning can prevent crown fires?

Treesearch

Mick Harrington

2008-01-01

Many land managers are attempting to lessen the probability of severe wildfire behavior and impacts, especially near communities, by manipulating canopy and surface fuel characteristics. Various interest groups have questioned the value of fuels treatments. In reality, apart from fire exposure when a real fire went through a treated stand, effectiveness of fuel...

Health-hazard evaluation report HETA-91-161-2225, Denver Police Department, Denver, Colorado

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

Lee, S.A.; McCammon, C.S.

1992-05-01

In response to a request from the Denver Police Department (SIC-9221) in Denver, Colorado, an investigation was made into lead (7439921) exposures during the use of different ammunition on the firing range. Ventilation rates were measured and personal breathing zone air samples were collected for ten officers during the firing of .45 caliber pistols. Nonlead primers were not yet available for .45 caliber ammunition. Air lead exposure ranged from 1.0 to 16 micrograms/cubic meter (microg/cu m). A slight improvement was noted in ventilation since an earlier NIOSH study had been performed at this site. The improvement resulted from the removalmore » of a 3 foot high partition along the floor on the firing line. There was still, however, turbulent air flow across the entire firing line and backflow in some of the shooting booths. The author concludes that there was no health hazard from lead overexposure at this site at this time, but recommends use of jacketed bullets, nonlead primers, and administrative controls to minimize lead exposures.« less

Assessing child time-activity patterns in relation to indoor cooking fires in developing countries: a methodological comparison.

PubMed

Barnes, Brendon; Mathee, Angela; Moiloa, Kebitsamang

2005-01-01

Indoor air pollution, caused by the indoor burning of biomass fuels, has been associated with an increased risk of child acute respiratory infections in developing countries. The amount of time that children spend in proximity to fires is a crucial determinant of the health impact of indoor air pollution. Researchers are reliant on social scientific methods to assess exposure based on child location patterns in relation to indoor fires. The inappropriate use of methods could lead to misclassification of exposure. The aim of this paper is to compare two methods (observations and questionnaire interview) with video analysis (which is thought to offer a more accurate assessment of exposure) in rural South African villages. Compared to video analysis, results show that observations may underestimate the amount of time that children spend very close (within 1.5 m) to fires. This is possibly due to reactivity caused by the presence of an observer. The questionnaire interview offers a more accurate assessment of the amounts of time that children spend within 1.5 m of fires at the expense of a detailed behavioural analysis. By drawing on the strengths and weaknesses of each, this paper discusses the appropriateness of methods to different research contexts.

Phase correlated adequate afferent action potentials as a drive of human spinal oscillators.

PubMed

Schalow, G

1993-12-01

1. By recording, with 2 pairs of wire electrodes, single-fibre action potentials (APs) from lower sacral nerve roots of a brain-dead human and a patient with spinal cord lesion, impulse patterns of afferent APs and impulse trains of oscillatory firing motoneurons could be identified and correlated. 2. Two highly activated secondary muscle spindle afferents increased and decreased their activity at about 0.3 Hz. The duration of the doublet interspike interval of a secondary spindle afferent fibre showed no correlation to the oscillation period of the motoneuron. 3. A continuously oscillatory firing motoneuron innervating the external and sphincter showed more transient breaks with the reduction of the number of phase correlated APs from 2 spindle afferents, indicating a looser oscillation. A transient brake of a 157 msec period alpha 2-oscillation could be correlated to the shift of a interspike interval distribution peak from 150 to 180 msec of the adequate afferent input, which suggests a transient loss of the necessary phase relation. 4. Oscillatory firing alpha 2-motoneurons innervating the external bladder and anal sphincters fired independently according to their phase correlated APs from the urinary bladder stretch receptor and muscle spindle afferents respectively; the bladder motoneuron slightly inhibited the anal motoneuron. 5. Receptors of the afferents and innervation sites of oscillatory firing motoneurons could be located within the urinary tract and the anal canal.

Topologically invariant macroscopic statistics in balanced networks of conductance-based integrate-and-fire neurons.

PubMed

Yger, Pierre; El Boustani, Sami; Destexhe, Alain; Frégnac, Yves

2011-10-01

The relationship between the dynamics of neural networks and their patterns of connectivity is far from clear, despite its importance for understanding functional properties. Here, we have studied sparsely-connected networks of conductance-based integrate-and-fire (IF) neurons with balanced excitatory and inhibitory connections and with finite axonal propagation speed. We focused on the genesis of states with highly irregular spiking activity and synchronous firing patterns at low rates, called slow Synchronous Irregular (SI) states. In such balanced networks, we examined the "macroscopic" properties of the spiking activity, such as ensemble correlations and mean firing rates, for different intracortical connectivity profiles ranging from randomly connected networks to networks with Gaussian-distributed local connectivity. We systematically computed the distance-dependent correlations at the extracellular (spiking) and intracellular (membrane potential) levels between randomly assigned pairs of neurons. The main finding is that such properties, when they are averaged at a macroscopic scale, are invariant with respect to the different connectivity patterns, provided the excitatory-inhibitory balance is the same. In particular, the same correlation structure holds for different connectivity profiles. In addition, we examined the response of such networks to external input, and found that the correlation landscape can be modulated by the mean level of synchrony imposed by the external drive. This modulation was found again to be independent of the external connectivity profile. We conclude that first and second-order "mean-field" statistics of such networks do not depend on the details of the connectivity at a microscopic scale. This study is an encouraging step toward a mean-field description of topological neuronal networks.

Family Resources as Protective Factors for Low-Income Youth Exposed to Community Violence.

PubMed

Hardaway, Cecily R; Sterrett-Hong, Emma; Larkby, Cynthia A; Cornelius, Marie D

2016-07-01

Exposure to community violence is a risk factor for internalizing and externalizing problems; however, resources within the family can decrease the likelihood that adolescents will experience internalizing and externalizing problems as a result of such exposure. This study investigates the potential moderating effects of kinship support (i.e., emotional and tangible support from extended family) and parental involvement on the relation between exposure to community violence (i.e., witnessing violence and violent victimization) and socioemotional adjustment (i.e., internalizing and externalizing problems) in low-income adolescents. The sample included 312 (50 % female; 71 % African American and 29 % White) low-income youth who participated in a longitudinal investigation when adolescents were age 14 (M age = 14.49 years) and again when they were 16 (M age = 16.49 years). Exposure to community violence at age 14 was related to more internalizing and externalizing problems at age 16. High levels of kinship support and parental involvement appeared to function as protective factors, weakening the association between exposure to violence and externalizing problems. Contrary to prediction, none of the hypothesized protective factors moderated the association between exposure to violence and internalizing problems. The results from this study suggest that both kinship support and parental involvement help buffer adolescents from externalizing problems that are associated with exposure to community violence.

Public health impacts of the severe haze in Equatorial Asia in September-October 2015: demonstration of a new framework for informing fire management strategies to reduce downwind smoke exposure

NASA Astrophysics Data System (ADS)

Koplitz, Shannon N.; Mickley, Loretta J.; Marlier, Miriam E.; Buonocore, Jonathan J.; Kim, Patrick S.; Liu, Tianjia; Sulprizio, Melissa P.; DeFries, Ruth S.; Jacob, Daniel J.; Schwartz, Joel; Pongsiri, Montira; Myers, Samuel S.

2016-09-01

In September-October 2015, El Niño and positive Indian Ocean Dipole conditions set the stage for massive fires in Sumatra and Kalimantan (Indonesian Borneo), leading to persistently hazardous levels of smoke pollution across much of Equatorial Asia. Here we quantify the emission sources and health impacts of this haze episode and compare the sources and impacts to an event of similar magnitude occurring under similar meteorological conditions in September-October 2006. Using the adjoint of the GEOS-Chem chemical transport model, we first calculate the influence of potential fire emissions across the domain on smoke concentrations in three receptor areas downwind—Indonesia, Malaysia, and Singapore—during the 2006 event. This step maps the sensitivity of each receptor to fire emissions in each grid cell upwind. We then combine these sensitivities with 2006 and 2015 fire emission inventories from the Global Fire Assimilation System (GFAS) to estimate the resulting population-weighted smoke exposure. This method, which assumes similar smoke transport pathways in 2006 and 2015, allows near real-time assessment of smoke pollution exposure, and therefore the consequent morbidity and premature mortality, due to severe haze. Our approach also provides rapid assessment of the relative contribution of fire emissions generated in a specific province to smoke-related health impacts in the receptor areas. We estimate that haze in 2015 resulted in 100 300 excess deaths across Indonesia, Malaysia and Singapore, more than double those of the 2006 event, with much of the increase due to fires in Indonesia’s South Sumatra Province. The model framework we introduce in this study can rapidly identify those areas where land use management to reduce and/or avoid fires would yield the greatest benefit to human health, both nationally and regionally.

Firefighter safety and photovoltaic installations research project

NASA Astrophysics Data System (ADS)

Backstrom, Robert; Dini, Dave

2012-10-01

Under the United States Department of Homeland Security (DHS) Assistance to Fire Fighters grant, UL LLC examined fire service concerns of photovoltaic (PV) systems. These concerns included firefighter vulnerability to electrical and casualty hazards when mitigating a fire involving photovoltaic (PV) modules systems. Findings include: 1. The electric shock hazard due to application of water is dependent on voltage, water conductivity, distance and spray pattern of the suppression stream. 2. Outdoor weather exposure rated electrical enclosures are not resistant to water penetration by fire hose streams. 3. Firefighter's gloves and boots afford limited protection against electrical shock provided the insulating surface is intact and dry. 4. "Turning off" an array is not a simple matter of opening a disconnect switch. 5. Tarps offer varying degrees of effectiveness. 6. Fire equipment scene lighting and exposure fires may illuminate PV systems sufficiently to cause a lock-on hazard. 7. Severely damaged PV arrays are capable of producing hazardous conditions. 8. Damage to modules from tools may result in both electrical and fire hazards. 9. Severing of conductors in both metal and plastic conduit results in electrical and fire hazards. 10. Responding personnel must stay away from the roofline in the event of modules or sections of an array sliding off the roof. 11. Fires under an array but above the roof may breach roofing materials and decking allowing fire to propagate into the attic space. Several tactical considerations were developed utilizing the data from the experiments.

Assessing landscape scale wildfire exposure for highly valued resources in a Mediterranean area.

PubMed

Alcasena, Fermín J; Salis, Michele; Ager, Alan A; Arca, Bachisio; Molina, Domingo; Spano, Donatella

2015-05-01

We used a fire simulation modeling approach to assess landscape scale wildfire exposure for highly valued resources and assets (HVR) on a fire-prone area of 680 km(2) located in central Sardinia, Italy. The study area was affected by several wildfires in the last half century: some large and intense fire events threatened wildland urban interfaces as well as other socioeconomic and cultural values. Historical wildfire and weather data were used to inform wildfire simulations, which were based on the minimum travel time algorithm as implemented in FlamMap. We simulated 90,000 fires that replicated recent large fire events in the area spreading under severe weather conditions to generate detailed maps of wildfire likelihood and intensity. Then, we linked fire modeling outputs to a geospatial risk assessment framework focusing on buffer areas around HVR. The results highlighted a large variation in burn probability and fire intensity in the vicinity of HVRs, and allowed us to identify the areas most exposed to wildfires and thus to a higher potential damage. Fire intensity in the HVR buffers was mainly related to fuel types, while wind direction, topographic features, and historically based ignition pattern were the key factors affecting fire likelihood. The methodology presented in this work can have numerous applications, in the study area and elsewhere, particularly to address and inform fire risk management, landscape planning and people safety on the vicinity of HVRs.

Exposure to open-fire cooking and cognitive performance in children.

PubMed

Munroe, Robert L; Gauvain, Mary

2012-01-01

We reexamined field data on cognitive performance in light of recent research that shows open-fire cooking--with its emission of harmful substances--to pose a risk to healthy physical development. Tests of three- to nine-year-old children in four communities around the world yielded evidence concerning block-building skills, memory, and the discernment of embedded figures. Naturalistic observations of these children were also undertaken in everyday settings. Open-fire cooking (as opposed to cooking on kerosene stoves) was associated with both lower cognitive performance and less frequent structured play at all ages. Although these correlational results do not reveal causal mechanisms, they are consistent with ideas about negative developmental consequences of exposure to open-fire cooking and suggest that research is needed on the effect on brain development of practices involving production of indoor smoke.

78 FR 69135 - Petitions for Modification of Application of Existing Mandatory Safety Standards

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-18

..., because there is a chance that the water can become polluted from some external event such as a fire or...) The nature of any emergency itself could cause an external water supply to be polluted, choked, or... Affected: 30 CFR 75.1101-1(b) (Deluge-type water spray systems). Modification Request: The petitioner...

The social costs of homeowner decisions in fire-prone communities: information, insurance, and amenities

Treesearch

Gwenlyn Busby; Gregory S. Amacher; Robert G. Haight

2013-01-01

In this article, we consider wildfire risk management decisions using a dynamic stochastic model of homeowner interaction in a setting where spatial externalities arise. Our central objective is to apply observations from the social science literature about homeowner preferences to this economic externality problem and determine how assumptions about insurance,...

Status of candidate materials for full-scale tests in the 737 fuselage

NASA Technical Reports Server (NTRS)

Supkis, D.

1979-01-01

The test program has the objectives to: (1) increase passenger evacuation time to a minimum of five minutes from commercial aircraft in case of a fire; (2) prevent an external fire from entering closed cabins for five minutes by using fire barrier materials in the exterior wall; (3) demonstrate that a closed cabin will not reach 400 F; and (4) prove that a fire near a cabin opening will not propagate through the cabin for a minimum of five minutes. The materials status is outlined for seat cushions, upholstery and associated seat materials, wall and ceiling panels, floor panels, carpet and carpet underlay, windows, cargo bay liners, insulation bagging, and thermal acoustical insulation.

Effects of wildland fire smoke on a tree-roosting bat: integrating a plume model, field measurements, and mammalian dose-response relationships

Treesearch

M.B. Dickinson; J.C. Norris; A.S. Bova; R.L. Kremens; V. Young; M.J. Lacki

2010-01-01

Faunal injury and mortality in wildland fires is a concern for wildlife and fire management although little work has been done on the mechanisms by which exposures cause their effects. In this paper, we use an integral plume model, field measurements, and models of carbon monoxide and heat effects to explore risk to tree-roosting bats during prescribed fires in mixed-...

Role of fire in the germination ecology of fountain grass (Pennisetum setaceum), an invasive African bunchgrass in Hawaii

Treesearch

Edith N. Adkins; Susan Cordell; Donald R. Drake

2011-01-01

Field and laboratory studies were carried out to test factors expected to be relevant for the germination of fountain grass: (1) light; (2) emergence of fountain grass seedlings from depths of 0, 2.5, and 5 cm; (3) fire passing over exposed and buried seeds; (4) laboratory heat treatment mimicking exposure to grass fire. Both fire in the field and heat applied in the...

The coal-fired gas turbine locomotive - A new look

NASA Technical Reports Server (NTRS)

Liddle, S. G.; Bonzo, B. B.; Purohit, G. P.

1983-01-01

Advances in turbomachine technology and novel methods of coal combustion may have made possible the development of a competitive coal fired gas turbine locomotive engine. Of the combustor, thermodynamic cycle, and turbine combinations presently assessed, an external combustion closed cycle regenerative gas turbine with a fluidized bed coal combustor is judged to be the best suited for locomotive requirements. Some merit is also discerned in external combustion open cycle regenerative systems and internal combustion open cycle regenerative gas turbine systems employing a coal gasifier. The choice of an open or closed cycle depends on the selection of a working fluid and the relative advantages of loop pressurization, with air being the most attractive closed cycle working fluid on the basis of cost.

Strength validation and fire endurance of glued-laminated timber beams

Treesearch

E. L. Schaffer; C. M. Marx; D. A. Bender; F. E. Woeste

A previous paper presented a reliability-based model to predict the strength of glued-laminated timber beams at both room temperature and during fire exposure. This Monte Carlo simulation procedure generates strength and fire endurance (time-to-failure, TTF) data for glued- laminated beams that allow assessment of mean strength and TTF as well as their variability....

Duff reduction by prescribed underburning in Douglas-fir.

Treesearch

David V. Sandberg

1980-01-01

Predictive equations for duff reduction and mineral soil exposure by prescribed fire are presented. An explanation is suggested for the dependence of duff combustion on surface fuel combustion. Surface fire duration and fuel moisture estimates of the National Fire-Danger Rating 1,000-hour timelag are the best predictors for reduction in moist duff. Duff layers with...

Modeling potential structure ignitions from flame radiation exposure with implications for wildland/urban interface fire management

Treesearch

Jack D. Cohen; Bret W. Butler

1998-01-01

Residential losses associated with wildland fires have become a serious international fire protection problem. The radiant heat flux from burning vegetation adjacent to a structure is a principal ignition factor. A thermal radiation and ignition model estimated structure ignition potential using designated flame characteristics (inferred from various types and...

Predicting duff and woody fuel consumed by prescribed fire in the Northern Rocky Mountains

Treesearch

James K. Brown; Michael A. Marsden; Kevin C. Ryan; Elizabeth D. Reinhardt

1985-01-01

Relationships for predicting duff reduction, mineral soil exposure, and consumption of downed woody fuel were determined to assist in planning prescribed fires. Independent variables included lower and entire duff moisture contents, loadings of downed woody fuels, duff depth, National Fire-Danger Rating System 1,000-hour moisture content, and Canadian Duff Moisture...

Effect of color on recall in fire prevention signing

Treesearch

William S. Folkman

1964-01-01

An exploratory experiment, designed to determine the effect of color on recall in fire prevention signing, was conducted on the San Bernardino National Forest. Background color of usual black on light yellow fire prevention signing, was changed to bright, high intensity orange. The change may have affected impact, but did not improve recall. Frequency of exposure to...

Dynamics of the exponential integrate-and-fire model with slow currents and adaptation.

PubMed

Barranca, Victor J; Johnson, Daniel C; Moyher, Jennifer L; Sauppe, Joshua P; Shkarayev, Maxim S; Kovačič, Gregor; Cai, David

2014-08-01

In order to properly capture spike-frequency adaptation with a simplified point-neuron model, we study approximations of Hodgkin-Huxley (HH) models including slow currents by exponential integrate-and-fire (EIF) models that incorporate the same types of currents. We optimize the parameters of the EIF models under the external drive consisting of AMPA-type conductance pulses using the current-voltage curves and the van Rossum metric to best capture the subthreshold membrane potential, firing rate, and jump size of the slow current at the neuron's spike times. Our numerical simulations demonstrate that, in addition to these quantities, the approximate EIF-type models faithfully reproduce bifurcation properties of the HH neurons with slow currents, which include spike-frequency adaptation, phase-response curves, critical exponents at the transition between a finite and infinite number of spikes with increasing constant external drive, and bifurcation diagrams of interspike intervals in time-periodically forced models. Dynamics of networks of HH neurons with slow currents can also be approximated by corresponding EIF-type networks, with the approximation being at least statistically accurate over a broad range of Poisson rates of the external drive. For the form of external drive resembling realistic, AMPA-like synaptic conductance response to incoming action potentials, the EIF model affords great savings of computation time as compared with the corresponding HH-type model. Our work shows that the EIF model with additional slow currents is well suited for use in large-scale, point-neuron models in which spike-frequency adaptation is important.

Current and historical individual data about exposure of workers in the rayon industry to carbon disulfide and their validity in calculating the cumulative dose.

PubMed

Göen, Thomas; Schramm, Axel; Baumeister, Thomas; Uter, Wolfgang; Drexler, Hans

2014-08-01

The objective of the study was to investigate how exposure to carbon disulfide (CS2) in a rayon-manufacturing plant has changed within two decades and whether it is possible to calculate valid data for the individual cumulative exposure. The data for CS2 concentration in air and biological exposure monitoring (2-thio-1,3-thiaxolidine-4-carboxylic acid (TTCA) in urine) from two cross-sectional studies, performed in 1992 (n = 362) and 2009 (n = 212) in a German rayon-manufacturing plant, were compared to data obtained from company-internal measurements between the studies. Using the data from the cross-sectional studies and company-internal data, cumulative external exposure and the cumulative internal exposure were calculated for each worker. External and internal CS2 exposure of the employees decreased from 1992 (medians 4.0 ppm and 1.63 mgTTCA/g creatinine) to 2009 (medians 2.5 ppm and 0.86 mg/g). However, company-internal CS2 data do not show a straight trend for this period. The annual medians of the company-internal measurement of external exposure to CS2 have varied between 2.7 and 8.4 ppm, in which median values exceeded 5 ppm generally since 2000. The annual medians for the company-internal biomonitoring assessment ranged between 1.2 and 2.8 mg/g creatinine. The cumulative CS2 exposure ranged from 8.5 to 869.5 ppm years for external exposure and between 1.30 and 176.2 mg/g creatinine years for the internal exposure. Significant correlations were found between the current air pollution and the internal exposure in 2009 but also between the cumulative external and internal CS2 exposure. Current exposure data, usually collected in cross-sectional studies, rarely allow a reliable statement on the cumulative dose, because of higher exposure in the past and of fluctuating courses of exposure. On the other hand, company-internal exposure data may be affected by non-representative measurement strategies. Some verification of the reliability of cumulative exposure data may be possible by testing the correlation between cumulative exposure data of external assessment and biological monitoring.

Health concerns of the U.S. fire service: perspectives from the firehouse.

PubMed

Jahnke, Sara A; Poston, Walker S C; Jitnarin, Nattinee; Haddock, C Keith

2012-01-01

Firefighters are expected to respond to any domestic emergency at a moment's notice, and therefore their health and readiness are key to the public safety net. Although emerging research is focusing on understanding firefighters' increased risk for disease and injury, the perspectives of fire service personnel is lacking. This study uses the cross-sectional qualitative data collection techniques of key informant interviews and focus groups. Data collection occurred with a national sample of firefighters from 28 (municipal and federal) career fire departments. Participants were 332 career firefighters (57.2%), company officers (23.4%), fire chiefs (15.4%), and other fire service personnel (3.9%). Focus groups and informant interviews were conducted with firefighters, fire chiefs, health promotion personnel, and medical directors to assess attitudes, opinions, and perceptions about firefighter health. Major themes that developed among fire service personnel included concerns about cancer, risk of cardiovascular disease, the importance of and barriers to physical fitness, the food culture of the firehouse, psychological stress resulting from repeated exposure to trauma, sleep disruptions, injuries, and risk for infectious disease. Health concerns identified by firefighters are juxtaposed with current efforts and trends within the national fire service. The health concerns of firefighters parallel both available epidemiological research and the health priorities of national fire service organizations. Unfortunately, these concerns often are in contrast with efforts by local governments to limit their financial liability for illnesses presumed to be caused by occupational exposures and long-held traditions in the fire service. This study highlights the need for epidemiological surveillance of firefighters and innovative health and organizational policy in the fire service. Future directions for the fire service, the public health community, and researchers are discussed.

Effects of a fire-retardant chemical to fathead minnows in experimental streams

USGS Publications Warehouse

Calfee, R.D.; Little, E.E.

2003-01-01

Background. Each year millions of liters of fire-retardant chemicals are applied to wildfires across the nation. Recent laboratory studies with long-term fire-retardant chemicals indicate a significant photoenhanced toxicity of products containing sodium ferrocyanide corrosion inhibitors. Our objective of this study was to determine the toxicity of fire-retardant chemicals to fathead minnows during exposure in experimental outdoor streams. Methods. Stream tests were conducted to determine the potential toxicity of a pulse of exposure as might occur when fire retardant chemical is rinsed from the watershed by rainfall. Two artificial 55-meter experimental streams were dosed with different concentrations of Fire-Trol?? GTS-R, or uncontaminated for a control. Replicate groups of fathead minnows were added to screened containers (10 fish per container) and exposed to retardant chemicals in the recirculating flow of the stream for up to 6 hours. Results and Discussion. Under field conditions toxicity of GTS-R only occurred in the presence of sunlight. When GTS-R was tested on sunny days, 100% mortality occurred. However, when tested during heavily overcast conditions, no mortality occurred. Conclusions. Lethal concentrations of cyanide were measured when GTS-R with YPS exposures were conducted under sunny conditions, but not under cloudy conditions, indicating that a minimum UV level is necessary to induce toxicity as well as the release of cyanide from YPS. The toxicity observed with GTS-R was likely associated with lethal concentrations of cyanide. Rainwater runoff following applications of this fire-retardant at the recommended rate could result in lethal concentrations in small ponds and streams receiving limited water flow under sunny conditions. Recommendations and Outlook. In addition to avoiding application to aquatic habitats, it is important to consider characteristics of the treated site including soil binding affinity and erosive properties.

Measurements of long-term external and internal radiation exposure of inhabitants of some villages of the Bryansk region of Russia after the Chernobyl accident.

PubMed

Bernhardsson, C; Zvonova, I; Rääf, C; Mattsson, S

2011-10-15

A Nordic-Soviet programme was initiated in 1990 to evaluate the external and internal radiation exposure of the inhabitants of several villages in the Bryansk region of Russia. This area was one of the number of areas particularly affected by the nuclear accident at the Chernobyl Nuclear Power Plant in 1986. Measurements were carried out yearly until 1998 and after that more irregularly; in 2000, 2006 and 2008 respectively. The effective dose estimates were based on individual thermoluminescent dosemeters and on in vivo measurements of the whole body content of (137)Cs (and (134)Cs during the first years of the programme). The decrease in total effective dose during the almost 2 decade follow-up was due to a continuous decrease in the dominating external exposure and a less decreasing but highly variable exposure from internal irradiation. In 2008, the observed average effective dose (i.e. the sum of external and internal exposure) from Chernobyl (137)Cs to the residents was estimated to be 0.3mSv y(-1). This corresponds to 8% of the estimated annual dose in 1990 and to 1% of the estimated annual dose in 1986. As a mean for the population group and for the period of the present study (2006-2008), the average yearly effective dose from Chernobyl cesium was comparable to the absorbed dose obtained annually from external exposure to cosmic radiation plus internal exposure to naturally occurring radionuclides in the human body. Our data indicate that the effective dose from internal exposure is becoming increasingly important as the body burdens of Chernobyl (137)Cs are decreasing more slowly than the external exposure. However, over the years there have been large individual variations in both the external and internal effective doses, as well as differences between the villages investigated. These variations and differences are presented and discussed in this paper. Copyright © 2011 Elsevier B.V. All rights reserved.

Lead exposure at firing ranges-a review.

PubMed

Laidlaw, Mark A S; Filippelli, Gabriel; Mielke, Howard; Gulson, Brian; Ball, Andrew S

2017-04-04

Lead (Pb) is a toxic substance with well-known, multiple, long-term, adverse health outcomes. Shooting guns at firing ranges is an occupational necessity for security personnel, police officers, members of the military, and increasingly a recreational activity by the public. In the United States alone, an estimated 16,000-18,000 firing ranges exist. Discharge of Pb dust and gases is a consequence of shooting guns. The objectives of this study are to review the literature on blood lead levels (BLLs) and potential adverse health effects associated with the shooting population. The search terms "blood lead", "lead poisoning", "lead exposure", "marksmen", "firearms", "shooting", "guns", "rifles" and "firing ranges" were used in the search engines Google Scholar, PubMed and Science Direct to identify studies that described BLLs in association with firearm use and health effects associated with shooting activities. Thirty-six articles were reviewed that included BLLs from shooters at firing ranges. In 31 studies BLLs > 10 μg/dL were reported in some shooters, 18 studies reported BLLs > 20 μg/dL, 17 studies > 30 μg/d, and 15 studies BLLs > 40 μg/dL. The literature indicates that BLLs in shooters are associated with Pb aerosol discharge from guns and air Pb at firing ranges, number of bullets discharged, and the caliber of weapon fired. Shooting at firing ranges results in the discharge of Pb dust, elevated BLLs, and exposures that are associated with a variety of adverse health outcomes. Women and children are among recreational shooters at special risk and they do not receive the same health protections as occupational users of firing ranges. Nearly all BLL measurements compiled in the reviewed studies exceed the current reference level of 5 μg/dL recommended by the U.S. Centers for Disease Control and Prevention/National Institute of Occupational Safety and Health (CDC/NIOSH). Thus firing ranges, regardless of type and user classification, currently constitute a significant and unmanaged public health problem. Prevention includes clothing changed after shooting, behavioural modifications such as banning of smoking and eating at firing ranges, improved ventilation systems and oversight of indoor ranges, and development of airflow systems at outdoor ranges. Eliminating lead dust risk at firing ranges requires primary prevention and using lead-free primers and lead-free bullets.

Local linear approximation of the Jacobian matrix better captures phase resetting of neural limit cycle oscillators.

PubMed

Oprisan, Sorinel Adrian

2014-01-01

One effect of any external perturbations, such as presynaptic inputs, received by limit cycle oscillators when they are part of larger neural networks is a transient change in their firing rate, or phase resetting. A brief external perturbation moves the figurative point outside the limit cycle, a geometric perturbation that we mapped into a transient change in the firing rate, or a temporal phase resetting. In order to gain a better qualitative understanding of the link between the geometry of the limit cycle and the phase resetting curve (PRC), we used a moving reference frame with one axis tangent and the others normal to the limit cycle. We found that the stability coefficients associated with the unperturbed limit cycle provided good quantitative predictions of both the tangent and the normal geometric displacements induced by external perturbations. A geometric-to-temporal mapping allowed us to correctly predict the PRC while preserving the intuitive nature of this geometric approach.

During running in place, grid cells integrate elapsed time and distance run

PubMed Central

Kraus, Benjamin J.; Brandon, Mark P.; Robinson, Robert J.; Connerney, Michael A.; Hasselmo, Michael E.; Eichenbaum, Howard

2015-01-01

Summary The spatial scale of grid cells may be provided by self-generated motion information or by external sensory information from environmental cues. To determine whether grid cell activity reflects distance traveled or elapsed time independent of external information, we recorded grid cells as animals ran in place on a treadmill. Grid cell activity was only weakly influenced by location but most grid cells and other neurons recorded from the same electrodes strongly signaled a combination of distance and time, with some signaling only distance or time. Grid cells were more sharply tuned to time and distance than non-grid cells. Many grid cells exhibited multiple firing fields during treadmill running, parallel to the periodic firing fields observed in open fields, suggesting a common mode of information processing. These observations indicate that, in the absence of external dynamic cues, grid cells integrate self-generated distance and time information to encode a representation of experience. PMID:26539893

Anthropogenic and biogenic sources of Ethylene and the potential for human exposure: A literature review.

PubMed

Morgott, David A

2015-11-05

This review examines available published information on ethylene emission sources, emission magnitudes, and inhalation exposures in order to assess those factors and circumstances that can affect human contact with this omnipresent gas. The results reveal that airborne ethylene concentrations at the ppb levels are commonplace and can arise in the vicinity of traffic corridors, forest fires, indoor kitchens, horticultural areas, oil fields, house fires, and petrochemical sites. The primary biogenic sources of ethylene derive from microbial activity in most soil and marine environments as well as its biological formation in wide variety of plant species. Sizable amounts of ethylene can also result from the burning of fossil fuels, forest and savanna fires, and crop residue combustion. Motor vehicle exhaust is the largest contributor to urban ethylene levels under most circumstances, but industrial flare releases and fugitive emissions may also be of relevance. Occupational exposures generally range up to about 50-100 ppm and have been documented for those working in the horticultural, petrochemical, and fire and rescue industries. Continuous personal monitoring at the community level has documented exposures of 3-4 ppb. These levels are more closely associated with the ethylene concentrations found indoors rather than outdoors indicating the importance of exposure sources found within the home. Indoor air sources of ethylene are associated with environmental tobacco smoke, wood or propane fuel use, fruit and vegetable storage, and cooking. Ethylene is not found in any consumer or commercial products and does not off-gas from building products to any appreciable extent. The review indicates that outdoor sources located some distance from the home do not make an appreciable contribution to personal exposures given the strength and variety of sources found in the immediate living environment. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Noise exposure assessment and abatement strategies at an indoor firing range.

PubMed

Kardous, Chucri A; Willson, Robert D; Hayden, Charles S; Szlapa, Piotr; Murphy, William J; Reeves, Efrem R

2003-08-01

Exposure to hazardous impulse noise is common during the firing of weapons at indoor firing ranges. The aims of this study were to characterize the impulse noise environment at a law enforcement firing range; document the insufficiencies found at the range from a health and safety standpoint; and provide noise abatement recommendations to reduce the overall health hazard to the auditory system. Ten shooters conducted a typical live-fire exercise using three different weapons--the Beretta.40 caliber pistol, the Remington.308 caliber shotgun, and the M4.223 caliber assault rifle. Measurements were obtained at 12 different positions throughout the firing range and adjacent areas using dosimeters and sound level meters. Personal and area measurements were recorded to a digital audio tape (DAT) recorder for further spectral analysis. Peak pressure levels inside the firing range reached 163 decibels (dB) in peak pressure. Equivalent sound levels (Leq) ranged from 78 decibels, A-weighted (dBA), in office area adjacent to the range to 122 dBA inside the range. Noise reductions from wall structures ranged from 29-44 dB. Noise abatement strategies ranged from simple noise control measures (such as sealing construction joints and leaks) to elaborate design modifications to eliminate structural-borne sounds using acoustical treatments. Further studies are needed to better characterize the effects of firing weapons in enclosed spaces on hearing and health in general.

Individual external doses below the lowest reference level of 1 mSv per year five years after the 2011 Fukushima nuclear accident among all children in Soma City, Fukushima: A retrospective observational study

PubMed Central

Murakami, Michio; Nomura, Shuhei; Morita, Tomohiro; Nishikawa, Yoshitaka; Leppold, Claire; Kato, Shigeaki; Kami, Masahiro

2017-01-01

After the 2011 Fukushima Daiichi nuclear power plant accident, little information has been available on individual doses from external exposure among residents living in radioactively contaminated areas near the nuclear plant; in the present study we evaluated yearly changes in the doses from external exposure after the accident and the effects of decontamination on external exposure. This study considered all children less than 16 years of age in Soma City, Fukushima who participated in annual voluntary external exposure screening programs during the five years after the accident (n = 5,363). In total, 14,405 screening results were collected. The median participant age was eight years. The geometric mean levels of annual additional doses from external exposure attributable to the Fukushima accident, decreased each year: 0.60 mSv (range: not detectable (ND)–4.29 mSv), 0.37 mSv (range: ND–3.61 mSv), 0.22 mSv (range: ND–1.44 mSv), 0.20 mSv (range: ND–1.87 mSv), and 0.17 mSv (range: ND–0.85 mSv) in 2011, 2012, 2013, 2014, and 2015, respectively. The proportion of residents with annual additional doses from external exposure of more than 1 mSv dropped from 15.6% in 2011 to zero in 2015. Doses from external exposure decreased more rapidly than those estimated from only physical decay, even in areas without decontamination (which were halved in 395 days from November 15, 2011), presumably due to the weathering effects. While the ratios of geometric mean doses immediately after decontamination to before were slightly lower than those during the same time in areas without decontamination, annual additional doses reduced by decontamination were small (0.04–0.24 mSv in the year of immediately after decontamination was completed). The results of this study showed that the levels of external exposure among Soma residents less than 16 years of age decreased during the five years after the Fukushima Daiichi nuclear power plant accident. Decontamination had only limited and temporal effects on reducing individual external doses. PMID:28235009

Developmental metaplasticity in neural circuit codes of firing and structure.

PubMed

Baram, Yoram

2017-01-01

Firing-rate dynamics have been hypothesized to mediate inter-neural information transfer in the brain. While the Hebbian paradigm, relating learning and memory to firing activity, has put synaptic efficacy variation at the center of cortical plasticity, we suggest that the external expression of plasticity by changes in the firing-rate dynamics represents a more general notion of plasticity. Hypothesizing that time constants of plasticity and firing dynamics increase with age, and employing the filtering property of the neuron, we obtain the elementary code of global attractors associated with the firing-rate dynamics in each developmental stage. We define a neural circuit connectivity code as an indivisible set of circuit structures generated by membrane and synapse activation and silencing. Synchronous firing patterns under parameter uniformity, and asynchronous circuit firing are shown to be driven, respectively, by membrane and synapse silencing and reactivation, and maintained by the neuronal filtering property. Analytic, graphical and simulation representation of the discrete iteration maps and of the global attractor codes of neural firing rate are found to be consistent with previous empirical neurobiological findings, which have lacked, however, a specific correspondence between firing modes, time constants, circuit connectivity and cortical developmental stages. Copyright © 2016 Elsevier Ltd. All rights reserved.

Community vulnerability to health impacts of wildland fire ...

EPA Pesticide Factsheets

Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community Health-Vulnerability Index (CHVI) based on factors known to increase the risks of health effects from air pollution and wildfire smoke exposures. These factors included county prevalence rates for asthma in children and adults, chronic obstructive pulmonary disease, hypertension, diabetes, obesity, percent of population 65 years of age and older, and indicators of socioeconomic status including poverty, education, income and unemployment. Using air quality simulated for the period between 2008 and 2012 over the continental U.S. we also characterized the population size at risk with respect to the level and duration of exposure to fire-originated fine particulate matter (fire-PM2.5) and CHVI. We estimate that 10% of the population (30.5 million) lived in the areas where the contribution of fire-PM2.5 to annual average ambient PM2.5 was high (>1.5 µg m3) and that 10.3 million individuals experienced unhealthy air quality levels for more than 10 days due to smoke. Using CHVI we identified the most vulnerable counties and determined that these communities experience more smoke exposures in comparison to less vulnerable communities. We describe the development of an index of community vulnerability for the health effects of smoke based o

ACUTE CARDIOVASCULAR EFFECTS OF FIREFIGHTING AND ACTIVE COOLING DURING REHABILITATION

PubMed Central

Burgess, Jefferey L.; Duncan, Michael D.; Hu, Chengcheng; Littau, Sally R.; Caseman, Delayne; Kurzius-Spencer, Margaret; Davis-Gorman, Grace; McDonagh, Paul F.

2012-01-01

Objectives To determine the cardiovascular and hemostatic effects of fire suppression and post-exposure active cooling. Methods Forty-four firefighters were evaluated prior to and after a 12 minute live-fire drill. Next, 50 firefighters undergoing the same drill were randomized to post-fire forearm immersion in 10°C water or standard rehabilitation. Results In the first study, heart rate and core body temperature increased and serum C-reactive protein decreased but there were no significant changes in fibrinogen, sE-selectin or sL-selectin. The second study demonstrated an increase in blood coagulability, leukocyte count, factors VIII and X, cortisol and glucose, and a decrease in plasminogen and sP-selectin. Active cooling reduced mean core temperature, heart rate and leukocyte count. Conclusions Live-fire exposure increased core temperature, heart rate, coagulability and leukocyte count; all except coagulability were reduced by active cooling. PMID:23090161

Synchronised firing patterns in a random network of adaptive exponential integrate-and-fire neuron model.

PubMed

Borges, F S; Protachevicz, P R; Lameu, E L; Bonetti, R C; Iarosz, K C; Caldas, I L; Baptista, M S; Batista, A M

2017-06-01

We have studied neuronal synchronisation in a random network of adaptive exponential integrate-and-fire neurons. We study how spiking or bursting synchronous behaviour appears as a function of the coupling strength and the probability of connections, by constructing parameter spaces that identify these synchronous behaviours from measurements of the inter-spike interval and the calculation of the order parameter. Moreover, we verify the robustness of synchronisation by applying an external perturbation to each neuron. The simulations show that bursting synchronisation is more robust than spike synchronisation. Copyright © 2017 Elsevier Ltd. All rights reserved.

A simplified test for adhesive behavior in wood sections exposed to fire

Treesearch

E. L. Schaffer

1968-01-01

A relatively simple test procedure was developed to evaluate the behavior of various adhesives near fire-exposed surfaces in laminated constructions. A number of sections cut from laminated blocks were exposed to fire on one surface. After this exposure, the sections were transversely cut, and the gluelines were examined for separation depth. In addition, the cool...

Fire prevention film spots for television ... narrator influence on knowledge and attitude changes

Treesearch

Gene C. Bernardi

1973-01-01

The relative effectiveness of 60-second films on fire prevention, with different narrators, was tested among high school students and by exposure on commercial television channels. The narrators were Smokey Bear, a Youth, and a Ranger. All three films were effective in teaching proper fire use practices to the high school classroom audience. In commercial TV showings,...

A model of gas mixing into single-entrance tree cavities during wildland fires

Treesearch

A.S. Bova; G. Bohrer; Matthew Dickinson

2011-01-01

The level of protection to fauna provided by tree cavities during wildland fires is not well understood. Here we present a model for estimating the transport of combustion gases into cylindrical, single-entrance cavities during exposures caused by different wildland fire scenarios. In these shelters, the entrance occurs near the top of the cavity. This empirical model...

Ecosystem restoration treatments affect soil physical and chemical properties in Appalachian mixed oak forests

Treesearch

Ralph E.J. Boerner; Jennifer a. Brinkman; Daniel A. Yaussy

2007-01-01

This study presents an analysis of the effect of ecosystem restoration treatments on soil properties in the oak forests of southern Ohio. The treatments were (1) prescribed fire, (2) mechanical thinning, (3) fire and thinning, and (4) passive management (control). Fire and thinning resulted in increased mineral soil exposure, with the effect decreasing by the fourth...

QM-8 field joint protection system, volume 7

NASA Technical Reports Server (NTRS)

Hale, Elgie

1989-01-01

The pre-launch functioning data of the Field Joint Protection System (JPS) used on QM-8 are presented. Also included is the post fire condition of the JPS components following the test firing of the motor. The JPS components are: field joint heaters; field joint sensors; field joint moisture seal; moisture seal kevlar retaining straps; field joint external extruded cork insulation; vent valve; power cables; and igniter heater.

Development of a Standard Test Scenario to Evaluate the Effectiveness of Portable Fire Extinguishers on Lithium-ion Battery Fires

NASA Technical Reports Server (NTRS)

Juarez, Alfredo; Harper, Susan A.; Hirsch, David B.; Carriere, Thierry

2013-01-01

Many sources of fuel are present aboard current spacecraft, with one especially hazardous source of stored energy: lithium ion batteries. Lithium ion batteries are a very hazardous form of fuel due to their self-sustaining combustion once ignited, for example, by an external heat source. Batteries can become extremely energetic fire sources due to their high density electrochemical energy content that may, under duress, be violently converted to thermal energy and fire in the form of a thermal runaway. Currently, lithium ion batteries are the preferred types of batteries aboard international spacecraft and therefore are routinely installed, collectively forming a potentially devastating fire threat to a spacecraft and its crew. Currently NASA is developing a fine water mist portable fire extinguisher for future use on international spacecraft. As its development ensues, a need for the standard evaluation of various types of fire extinguishers against this potential threat is required to provide an unbiased means of comparing between fire extinguisher technologies and ranking them based on performance.

Patterns of poverty exposure and children's trajectories of externalizing and internalizing behaviors.

PubMed

Comeau, Jinette; Boyle, Michael H

2018-04-01

Using data from the Child Supplement of the National Longitudinal Survey of Youth, we compare trajectories of externalizing and internalizing behaviors among children exposed to five patterns of poverty from birth to age 14: always or never poor - stable patterns; a single transition into or out of poverty, or repeated fluctuations in and out of poverty - changing patterns. We also examine how low maternal education and single parenthood interact with these poverty exposures to compound their adverse effects. Finally, we compare the magnitude of effects associated with the patterns of poverty exposure, as well as their interactions with low maternal education and single parenthood, on trajectories of externalizing and internalizing behaviors to determine if they are significantly different. Results reveal that initial levels and rates of change in children's trajectories of externalizing and internalizing behaviors are similar across the three changing patterns of poverty exposure, leading us to combine them into a single group representing intermittent poverty. Initial disparities between children who are never poor and their counterparts who are always or intermittently poor are constant over time for internalizing behaviors and grow in magnitude for externalizing behaviors. The cumulative negative effect of poverty exposure over time is stronger for externalizing vs. internalizing behaviors. Low maternal education compounds the adverse effects of persistent poverty, an effect that is similar for externalizing and internalizing behaviors.

Dynamics of networks of excitatory and inhibitory neurons in response to time-dependent inputs.

PubMed

Ledoux, Erwan; Brunel, Nicolas

2011-01-01

We investigate the dynamics of recurrent networks of excitatory (E) and inhibitory (I) neurons in the presence of time-dependent inputs. The dynamics is characterized by the network dynamical transfer function, i.e., how the population firing rate is modulated by sinusoidal inputs at arbitrary frequencies. Two types of networks are studied and compared: (i) a Wilson-Cowan type firing rate model; and (ii) a fully connected network of leaky integrate-and-fire (LIF) neurons, in a strong noise regime. We first characterize the region of stability of the "asynchronous state" (a state in which population activity is constant in time when external inputs are constant) in the space of parameters characterizing the connectivity of the network. We then systematically characterize the qualitative behaviors of the dynamical transfer function, as a function of the connectivity. We find that the transfer function can be either low-pass, or with a single or double resonance, depending on the connection strengths and synaptic time constants. Resonances appear when the system is close to Hopf bifurcations, that can be induced by two separate mechanisms: the I-I connectivity and the E-I connectivity. Double resonances can appear when excitatory delays are larger than inhibitory delays, due to the fact that two distinct instabilities exist with a finite gap between the corresponding frequencies. In networks of LIF neurons, changes in external inputs and external noise are shown to be able to change qualitatively the network transfer function. Firing rate models are shown to exhibit the same diversity of transfer functions as the LIF network, provided delays are present. They can also exhibit input-dependent changes of the transfer function, provided a suitable static non-linearity is incorporated.

Transition between Functional Regimes in an Integrate-And-Fire Network Model of the Thalamus

PubMed Central

Barardi, Alessandro; Mazzoni, Alberto

2016-01-01

The thalamus is a key brain element in the processing of sensory information. During the sleep and awake states, this brain area is characterized by the presence of two distinct dynamical regimes: in the sleep state activity is dominated by spindle oscillations (7 − 15 Hz) weakly affected by external stimuli, while in the awake state the activity is primarily driven by external stimuli. Here we develop a simple and computationally efficient model of the thalamus that exhibits two dynamical regimes with different information-processing capabilities, and study the transition between them. The network model includes glutamatergic thalamocortical (TC) relay neurons and GABAergic reticular (RE) neurons described by adaptive integrate-and-fire models in which spikes are induced by either depolarization or hyperpolarization rebound. We found a range of connectivity conditions under which the thalamic network composed by these neurons displays the two aforementioned dynamical regimes. Our results show that TC-RE loops generate spindle-like oscillations and that a minimum level of clustering (i.e. local connectivity density) in the RE-RE connections is necessary for the coexistence of the two regimes. We also observe that the transition between the two regimes occurs when the external excitatory input on TC neurons (mimicking sensory stimulation) is large enough to cause a significant fraction of them to switch from hyperpolarization-rebound-driven firing to depolarization-driven firing. Overall, our model gives a novel and clear description of the role that the two types of neurons and their connectivity play in the dynamical regimes observed in the thalamus, and in the transition between them. These results pave the way for the development of efficient models of the transmission of sensory information from periphery to cortex. PMID:27598260

Assessing Climate Change Impacts on Wildfire Exposure in Mediterranean Areas.

PubMed

Lozano, Olga M; Salis, Michele; Ager, Alan A; Arca, Bachisio; Alcasena, Fermin J; Monteiro, Antonio T; Finney, Mark A; Del Giudice, Liliana; Scoccimarro, Enrico; Spano, Donatella

2017-10-01

We used simulation modeling to assess potential climate change impacts on wildfire exposure in Italy and Corsica (France). Weather data were obtained from a regional climate model for the period 1981-2070 using the IPCC A1B emissions scenario. Wildfire simulations were performed with the minimum travel time fire spread algorithm using predicted fuel moisture, wind speed, and wind direction to simulate expected changes in weather for three climatic periods (1981-2010, 2011-2040, and 2041-2070). Overall, the wildfire simulations showed very slight changes in flame length, while other outputs such as burn probability and fire size increased significantly in the second future period (2041-2070), especially in the southern portion of the study area. The projected changes fuel moisture could result in a lengthening of the fire season for the entire study area. This work represents the first application in Europe of a methodology based on high resolution (250 m) landscape wildfire modeling to assess potential impacts of climate changes on wildfire exposure at a national scale. The findings can provide information and support in wildfire management planning and fire risk mitigation activities. © 2016 Society for Risk Analysis.

Fire service instructor's undergarment choice to reduce Interleukin-6 and minimise physiological and perceptual strain.

PubMed

Watkins, Emily R; Richardson, Alan J

2017-01-01

Fire Service Instructors frequently experience high levels of physiological and perceptual strain during live fire exposures. Instructors are also at risk of cardiovascular illnesses, with cardiac death being the greatest cause of fire fighter death. Current practice for UK instructors is to select undergarment type based on personal preference, between a boiler suit (BOILER) and a wicking base layer (WBL). Research suggests that shorts and t-shirt (SHORTS) may also be a beneficial alternative undergarment choice. The UK South East Fire Service requested an investigation to identify if undergarment selection can lessen the strain experienced by instructors, and reduce the acute inflammatory response to fire exposures. Eight males completed three 45min sessions in a heat chamber (49.5±1.4°C and 16.9±4.3% RH) whilst performing intermittent walking. At the end of heat exposure change in heart rate was not effected by garment type (p=0.061, ηp 2 =0.373). Change in rectal temperature was different between garments (p=0.009, η p 2 =0.271), with trends suggesting that BOILER resulted in a greater change (1.03±0.60°C) than SHORTS (0.76±0.37°C, p=0.589, d=0.21) and WBL (0.72±0.33°C, p=0.545, d=0.25). Interleukin-6 post exposure was greater for BOILER (6.96±0.28pgmL -1 ) than both SHORTS (6.59±0.30pgmL -1 , p=0.043, d=0.42) and WBL (6.45±0.43pgmL -1 , p=0.031, d=0.51). Overall, undergarment type had little impact on physiological or perceptual strain. However, wearing WBL or SHORTS may reduce the inflammatory response, and consequently decrease the risk of cardiovascular events. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Mortality due to Vegetation Fire–Originated PM2.5 Exposure in Europe—Assessment for the Years 2005 and 2008

PubMed Central

Kollanus, Virpi; Prank, Marje; Gens, Alexandra; Soares, Joana; Vira, Julius; Kukkonen, Jaakko; Sofiev, Mikhail; Salonen, Raimo O.; Lanki, Timo

2016-01-01

Background: Vegetation fires can release substantial quantities of fine particles (PM2.5), which are harmful to health. The fire smoke may be transported over long distances and can cause adverse health effects over wide areas. Objective: We aimed to assess annual mortality attributable to short-term exposures to vegetation fire–originated PM2.5 in different regions of Europe. Methods: PM2.5 emissions from vegetation fires in Europe in 2005 and 2008 were evaluated based on Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data on fire radiative power. Atmospheric transport of the emissions was modeled using the System for Integrated modeLling of Atmospheric coMposition (SILAM) chemical transport model. Mortality impacts were estimated for 27 European countries based on a) modeled daily PM2.5 concentrations and b) population data, both presented in a 50 × 50 km2 spatial grid; c) an exposure–response function for short-term PM2.5 exposure and daily nonaccidental mortality; and d) country-level data for background mortality risk. Results: In the 27 countries overall, an estimated 1,483 and 1,080 premature deaths were attributable to the vegetation fire–originated PM2.5 in 2005 and 2008, respectively. Estimated impacts were highest in southern and eastern Europe. However, all countries were affected by fire-originated PM2.5, and even the lower concentrations in western and northern Europe contributed substantially (~ 30%) to the overall estimate of attributable mortality. Conclusions: Our assessment suggests that air pollution caused by PM2.5 released from vegetation fires is a notable risk factor for public health in Europe. Moreover, the risk can be expected to increase in the future as climate change proceeds. This factor should be taken into consideration when evaluating the overall health and socioeconomic impacts of these fires. Citation: Kollanus V, Prank M, Gens A, Soares J, Vira J, Kukkonen J, Sofiev M, Salonen RO, Lanki T. 2017. Mortality due to vegetation fire–originated PM2.5 exposure in Europe—assessment for the years 2005 and 2008. Environ Health Perspect 125:30–37; http://dx.doi.org/10.1289/EHP194 PMID:27472655

External radiation dose and cancer mortality among French nuclear workers: considering potential confounding by internal radiation exposure.

PubMed

Fournier, L; Laurent, O; Samson, E; Caër-Lorho, S; Laroche, P; Le Guen, B; Laurier, D; Leuraud, K

2016-11-01

French nuclear workers have detailed records of their occupational exposure to external radiation that have been used to examine associations with subsequent cancer mortality. However, some workers were also exposed to internal contamination by radionuclides. This study aims to assess the potential for bias due to confounding by internal contamination of estimates of associations between external radiation exposure and cancer mortality. A cohort of 59,004 workers employed for at least 1 year between 1950 and 1994 by CEA (Commissariat à l'Energie Atomique), AREVA NC, or EDF (Electricité de France) and badge-monitored for external radiation exposure were followed through 2004 to assess vital status and cause of death. A flag based on a workstation-exposure matrix defined four levels of potential for internal contamination. Standardized mortality ratios were assessed for each level of the internal contamination indicator. Poisson regression was used to quantify associations between external radiation exposure and cancer mortality, adjusting for potential internal contamination. For solid cancer, the mortality deficit tended to decrease as the levels of potential for internal contamination increased. For solid cancer and leukemia excluding chronic lymphocytic leukemia, adjusting the dose-response analysis on the internal contamination indicator did not markedly change the excess relative risk per Sievert of external radiation dose. This study suggests that in this cohort, neglecting information on internal dosimetry while studying the association between external dose and cancer mortality does not generate a substantial bias. To investigate more specifically the health effects of internal contamination, an effort is underway to estimate organ doses due to internal contamination.

Who, What, When, Where? Determining the Health Implications of Wildfire Smoke Exposure

NASA Astrophysics Data System (ADS)

Ford, B.; Lassman, W.; Gan, R.; Burke, M.; Pfister, G.; Magzamen, S.; Fischer, E. V.; Volckens, J.; Pierce, J. R.

2016-12-01

Exposure to poor air quality is associated with negative impacts on human health. A large natural source of PM in the western U.S. is from wildland fires. Accurately attributing health endpoints to wildland-fire smoke requires a determination of the exposed population. This is a difficult endeavor because most current methods for monitoring air quality are not at high temporal and spatial resolutions. Therefore, there is a growing effort to include multiple datasets and create blended products of smoke exposure that can exploit the strengths of each dataset. In this work, we combine model (WRF-Chem) simulations, NASA satellite (MODIS) observations, and in-situ surface monitors to improve exposure estimates. We will also introduce a social-media dataset of self-reported smoke/haze/pollution to improve population-level exposure estimates for the summer of 2015. Finally, we use these detailed exposure estimates in different epidemiologic study designs to provide an in-depth understanding of the role wildfire exposure plays on health outcomes.

People, El Niño southern oscillation and fire in Australia: fire regimes and climate controls in hummock grasslands

PubMed Central

Bird, Douglas W.; Codding, Brian F.

2016-01-01

While evidence mounts that indigenous burning has a significant role in shaping pyrodiversity, the processes explaining its variation across local and external biophysical systems remain limited. This is especially the case with studies of climate–fire interactions, which only recognize an effect of humans on the fire regime when they act independently of climate. In this paper, we test the hypothesis that an anthropogenic fire regime (fire incidence, size and extent) does not covary with climate. In the lightning regime, positive El Niño southern oscillation (ENSO) values increase lightning fire incidence, whereas La Niña (and associated increases in prior rainfall) increase fire size. ENSO has the opposite effect in the Martu regime, decreasing ignitions in El Niño conditions without affecting fire size. Anthropogenic ignition rates covary positively with high antecedent rainfall, whereas fire size varies only with high temperatures and unpredictable winds, which may reduce control over fire spread. However, total area burned is similarly predicted by antecedent rainfall in both regimes, but is driven by increases in fire size in the lightning regime, and fire number in the anthropogenic regime. We conclude that anthropogenic regimes covary with climatic variation, but detecting the human–climate–fire interaction requires multiple measures of both fire regime and climate. This article is part of the themed issue ‘The interaction of fire and mankind’. PMID:27216513

Occupational Noise Exposure on a Royal Navy Warship During Weapon Fire

PubMed Central

Paddan, Gurmail Singh

2016-01-01

Introduction: Measurements were made of the sound pressure levels on a military ship HMS Grimsby during firing of a Heavy Machine Gun (HMG) mounted on the starboard bridge wing. The measurement positions comprised three locations on the ship's bridge (the wheelhouse) and one location on the starboard bridge wing. Equipment and Procedure: The three locations on the bridge were the starboard door, centre and port door. A total of 255 burst firings were measured during the survey comprising 850 rounds with each burst encompassing from 1 to 10 rounds. Analysis: The data have been assessed and interpreted in accordance with the Control of Noise at Work Regulations 2005. Results: The highest peak sound pressure levels measured on the bridge wing and on the bridge were 160.7 dB(C) (2170 Pa) and 122.7 dB(C) (27.3 Pa), respectively. The highest sound exposure levels measured on the bridge wing and on the bridge corresponding to one round being fired were 127.8 dB(A) and 88.9 dB(A), respectively. The ship's structure provided about 40 dB attenuation in the transmitted noise. Discussion: The operator of the weapon would be required to wear some form of hearing protection. On the basis of the measured peak noise levels, there would be no requirement for bridge crew to wear any hearing protection during firing of a HMG. However, crew exposure to noise on the bridge is likely to exceed the upper exposure action value corresponding to 85 dB(A) after about 11,750 rounds. Conclusions: Measurements made on the bridge wings are likely to be affected by reflections from the ship's structure. PMID:27762256

Occupational noise exposure on a Royal Navy warship during weapon fire.

PubMed

Paddan, Gurmail Singh

2016-01-01

Measurements were made of the sound pressure levels on a military ship HMS Grimsby during firing of a Heavy Machine Gun (HMG) mounted on the starboard bridge wing. The measurement positions comprised three locations on the ship's bridge (the wheelhouse) and one location on the starboard bridge wing. Equipment and Procedure: The three locations on the bridge were the starboard door, centre and port door. A total of 255 burst firings were measured during the survey comprising 850 rounds with each burst encompassing from 1 to 10 rounds. The data have been assessed and interpreted in accordance with the Control of Noise at Work Regulations 2005. The highest peak sound pressure levels measured on the bridge wing and on the bridge were 160.7 dB(C) (2170 Pa) and 122.7 dB(C) (27.3 Pa), respectively. The highest sound exposure levels measured on the bridge wing and on the bridge corresponding to one round being fired were 127.8 dB(A) and 88.9 dB(A), respectively. The ship's structure provided about 40 dB attenuation in the transmitted noise. The operator of the weapon would be required to wear some form of hearing protection. On the basis of the measured peak noise levels, there would be no requirement for bridge crew to wear any hearing protection during firing of a HMG. However, crew exposure to noise on the bridge is likely to exceed the upper exposure action value corresponding to 85 dB(A) after about 11,750 rounds. Measurements made on the bridge wings are likely to be affected by reflections from the ship's structure.

Health outcomes associated with smoke exposure in Albuquerque, New Mexico, during the 2011 Wallow fire.

PubMed

Resnick, Adam; Woods, Brian; Krapfl, Heidi; Toth, Barbara

2015-01-01

This study examined the association between PM2.5 levels and emergency department (ED) visits for selected health outcomes in Albuquerque, New Mexico, during the Wallow fire of 2011. Measurements of 24-hour average concentrations of PM2.5 obtained from the City of Albuquerque were used to calculate wildfire smoke exposure in Albuquerque. Daily ED visits were collected by the New Mexico Department of Health from individual nonfederal licensed facilities in the Albuquerque area. Poisson regression was used to assess the relationship between ED visits for selected respiratory and cardiovascular conditions and varying levels of PM2.5 exposure. Albuquerque, New Mexico. Patients visiting an ED for select conditions before, during, and after the wildfire. Relative increase in ED visits for selected conditions during the wildfire period. Analysis of PM2.5 exposure data and ED visits in Albuquerque before and during the Wallow fire indicated that compared with the period prior to the fire, there was an increased risk of ED visits for some respiratory and cardiovascular conditions during heavy smoke conditions, and risk varied by age and sex. The population of 65+ years was especially at risk for increased ED visits. There was a significantly increased risk of ED visits among the 65+ population for asthma (RR [relative rate] = 1.73, 95% confidence interval [CI] = 1.03-2.93) and for diseases of the veins, lymphatic and circulatory system (RR = 1.56, 95% CI = 1.00-2.43). For the age group of 20 to 64 years, there was a statistically significant increase in ED visits for diseases of pulmonary circulation (RR = 2.64, 95% CI = 1.42-4.9) and for cerebrovascular disease (RR = 1.69, 95% CI = 1.03-2.77). High levels of PM2.5 exposure due to the Wallow fire were associated with increased ED visits for respiratory and cardiovascular conditions in Albuquerque. More effective and targeted preventive measures are necessary to reduce morbidity rates associated with wildfire smoke exposure among vulnerable populations.

14 CFR 137.29 - General.

Code of Federal Regulations, 2010 CFR

2010-01-01

... this chapter and involving only the dispensing of water on forest fires by rotorcraft external-load... agriculture, horticulture, or forest preservation in accordance with the operating rules of this subpart. (d...

14 CFR 137.29 - General.

Code of Federal Regulations, 2011 CFR

2011-01-01

... this chapter and involving only the dispensing of water on forest fires by rotorcraft external-load... agriculture, horticulture, or forest preservation in accordance with the operating rules of this subpart. (d...

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

Laurinat, J.; Kesterson, M.; Hensel, S.

The documented safety analysis for the Savannah River Site evaluates the consequences of a postulated 1000 °C fire in a glovebox. The radiological dose consequences for a pressurized release of plutonium oxide powder during such a fire depend on the maximum pressure that is attained inside the oxide storage vial. To enable evaluation of the dose consequences, pressure transients and venting flow rates have been calculated for exposure of the storage vial to the fire. A standard B vial with a capacity of approximately 8 cc was selected for analysis. The analysis compares the pressurization rate from heating and evaporationmore » of moisture adsorbed onto the plutonium oxide contents of the vial with the pressure loss due to venting of gas through the threaded connection between the vial cap and body. Tabulated results from the analysis include maximum pressures, maximum venting velocities, and cumulative vial volumes vented during the first 10 minutes of the fire transient. Results are obtained for various amounts of oxide in the vial, various amounts of adsorbed moisture, different vial orientations, and different surface fire exposures.« less

Dynamical mechanism for sharp orientation tuning in an integrate-and-fire model of a cortical hypercolumn.

PubMed

Bressloff, P C; Bressloff, N W; Cowan, J D

2000-11-01

Orientation tuning in a ring of pulse-coupled integrate-and-fire (IF) neurons is analyzed in terms of spontaneous pattern formation. It is shown how the ring bifurcates from a synchronous state to a non-phase-locked state whose spike trains are characterized by clustered but irregular fluctuations of the interspike intervals (ISIs). The separation of these clusters in phase space results in a localized peak of activity as measured by the time-averaged firing rate of the neurons. This generates a sharp orientation tuning curve that can lock to a slowly rotating, weakly tuned external stimulus. Under certain conditions, the peak can slowly rotate even to a fixed external stimulus. The ring also exhibits hysteresis due to the subcritical nature of the bifurcation to sharp orientation tuning. Such behavior is shown to be consistent with a corresponding analog version of the IF model in the limit of slow synaptic interactions. For fast synapses, the deterministic fluctuations of the ISIs associated with the tuning curve can support a coefficient of variation of order unity.

Effect of fire-retardant treatment on plywood pH and the relationship of pH to strength properties

Treesearch

S. T. Lebow; J. E. Winandy

1999-01-01

This paper investigates the relationship between wood pH and the strength properties of fire-retardant-treated (FRT) plywood, as it is affected by fire-retardant (FR) formulations, processing variables, and extended high temperature exposure conditions. The objectives of this study were to (1) identify the effect of post-treatment kiln-drying temperature, followed by...

External-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon between 1978 and 1998.

PubMed

Strand, Leif Aage; Martinsen, Jan Ivar; Fadum, Elin Anita; Borud, Einar Kristian

2017-08-01

To investigate external-cause mortality among 21 609 Norwegian male military peacekeepers deployed to Lebanon during 1978-1998. The cohort was followed from the 1st day of deployment through 2013, and mortality during deployment and post discharge was assessed using SMRs calculated from national rates in Norway. Poisson regression was used to see the effect of high-conflict versus low-conflict exposure. For the total cohort, external-cause mortality was within expected values during deployment (SMR=0.80) and post discharge (SMR=1.05). In the low-conflict exposure group, a lower mortality from all external causes (SMR=0.77), transport accidents (SMR=0.55) and accidental poisoning (SMR=0.53) was seen. The high-conflict exposure group showed an elevated mortality from all external causes (SMR=1.20), transport accidents (SMR=1.51) and suicide (SMR=1.30), but these risks were elevated only during the first 5 years after discharge. This group also showed elevated mortality from all external causes (rate ratio, RR=1.49), and for transport accidents (RR=3.30) when compared with the low-conflict exposure group. Overall external-cause mortality among our peacekeepers was equal to national rates during deployment and post discharge. High-conflict exposure was associated with elevated mortality from all external causes, transport accidents and suicide during the first 5 years after discharge from service. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

This loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

The role of fire in deep time ecosystems

NASA Astrophysics Data System (ADS)

Scott, Andrew C.; Bond, William J.; Collinson, Margaret E.; Glasspool, Ian J.; Brown, Sarah; Braman, Dennis R.

2010-05-01

Fires are very widespread in the world today and fire has also been common in the deep past. Fire is important in structuring contemporary World vegetation maintaining extensive open vegetation where the climate has the potential to support closed forests. The influence of fire on the structure of vegetation and plant traits present in a community vary depending on the fire regime. The fire regime is the characteristic pattern of fire frequency, severity (amount of biomass removed) and spatial extent. Fire regimes depend on the synergy between external physical factors and the properties of vegetation. Changes in the fire regime can be brought about by changes in external conditions such as climate, but also by changes in vegetation such as changes in flammability or productivity that influence the amount of fuel. For example, invasion of grasses into closed wooded habitats has initiated a ‘grass fire cycle' in many parts of the world triggering cascading changes in vegetation structure and composition from forest to open grassland or savanna woodland. The spread of flammable invasive species, especially grasses, has even altered fire regimes of fire-dependent flammable communities causing catastrophic ecosystem changes. We suggest that the spread of angiosperms in the Cretaceous was promoted by the development of novel fire regimes linked to the evolution of novel, highly productive (and flammable) plants. Within the limits of physical constraints on fire occurrence, Cretaceous angiosperms would have initiated a positive feedback analogous to the grass-fire cycle rapidly accumulating fuel that promoted more frequent fires, which maintained open habitats in which rapid growth-traits of angiosperms would be most favoured promoting rapid fuel accumulation etc. Frequent fires would have altered vegetation structure and composition both by increasing mortality rates of fire-damaged trees and reducing recruitment rates of seedlings and saplings where fires recurred before juveniles had reached "fire-proof" sizes. The effect would be to create more open conditions favouring plants with the angiosperm innovations of high photosynthetic rates, rapid maturation and rapid reproduction relative to gymnosperms. Fire has some analogies to large vertebrate herbivory, particularly in the potential to open forests and create habitat for low-growing sun-loving plants over extensive areas. The role of fire in favouring low-growing ‘ruderal', plants of open habitats is similar to that proposed for dinosaurs. A switch from high-browsing dinosaurs in the Jurassic to low-browsing dinosaurs in the Cretaceous has been noted and it has been argued that the switch in browse height would favour fast-growing angiosperms. The dinosaur hypothesis has recently been tested and found wanting, for example in the timing and coincidence of angiosperm abundance and low vs. high-browsing dinosaurs. Our research of the co-occurrence of dinosaur remains and charcoal assemblages in Dinosaur Provincial Park, Alberta, has suggested that it was a dominance of gymnospermous, woody vegetation that was ravaged by fire. In addition, the co-occurrence of dinosaur remains and charcoal is significant in demonstrating that the some dinosaur bone beds may have formed as a result of extensive post-fire erosion/rapid deposition cycles. In this paper we consider the evidence for and against fire as a major factor promoting vegetation change and angiosperm spread in the Cretaceous.

Weapon System Implications of RLPG Technology

DTIC Science & Technology

2000-01-01

the extreme emphasis placed on minimizing volume under armor . For an RLPG, the space required is further reduced because, unlike the case with an SPG...ensuring that all the on-board missiles can be launched from under armor . Currently, vehicle-launched missiles are fired from racks of four launch...reload is not done under armor . External, manual reload for the direct-fire role is simply not feasible operationally. It is possible to design a

Childrearing Violence and Child Adjustment Following Exposure to Kenyan Post-election Violence

PubMed Central

Skinner, Ann T.; Oburu, Paul; Lansford, Jennifer E.; Bacchini, Dario

2014-01-01

Objective This study examines parents' and children's exposure to short-term political violence and the relation between childrearing violence and child adjustment following widespread violence that erupted in Kisumu, Kenya after the disputed presidential election in December 2007. Method Mothers of 100 Luo children (mean age = 8.46 years, 61% female) reported on their own use of childrearing violence at Time 1, approximately 4 months after the disputed election, and again at Times 2 (n = 95) and 3 (n = 95), approximately 12 and 24 months later, respectively. At Time 2, mothers reported about post-election violence directed at them and about their children's exposure to post-election violence. Children reported about their own externalizing behaviors at Times 1, 2, and 3. Results Children's exposure to post-election violence was related to Time 2 externalizing behavior, and childrearing violence at Time 1 predicted child externalizing behavior at Time 2. Exposure to post-election violence was not directly related to either childrearing violence or children's externalizing behavior by Time 3, although children's externalizing at Time 2 predicted more childrearing violence at Time 3. Conclusion These results support earlier work that links childrearing violence and children's exposure to political violence with increases in child externalizing behavior, but examined these links in the under-studied area of short-term political violence. Even though sudden and severe political violence may subside significantly in weeks or months, increased attention to long-term effects on parenting and child adjustment is warranted. PMID:24639914

Childrearing Violence and Child Adjustment Following Exposure to Kenyan Post-election Violence.

PubMed

Skinner, Ann T; Oburu, Paul; Lansford, Jennifer E; Bacchini, Dario

2014-01-01

This study examines parents' and children's exposure to short-term political violence and the relation between childrearing violence and child adjustment following widespread violence that erupted in Kisumu, Kenya after the disputed presidential election in December 2007. Mothers of 100 Luo children (mean age = 8.46 years, 61% female) reported on their own use of childrearing violence at Time 1, approximately 4 months after the disputed election, and again at Times 2 ( n = 95) and 3 ( n = 95), approximately 12 and 24 months later, respectively. At Time 2, mothers reported about post-election violence directed at them and about their children's exposure to post-election violence. Children reported about their own externalizing behaviors at Times 1, 2, and 3. Children's exposure to post-election violence was related to Time 2 externalizing behavior, and childrearing violence at Time 1 predicted child externalizing behavior at Time 2. Exposure to post-election violence was not directly related to either childrearing violence or children's externalizing behavior by Time 3, although children's externalizing at Time 2 predicted more childrearing violence at Time 3. These results support earlier work that links childrearing violence and children's exposure to political violence with increases in child externalizing behavior, but examined these links in the under-studied area of short-term political violence. Even though sudden and severe political violence may subside significantly in weeks or months, increased attention to long-term effects on parenting and child adjustment is warranted.

Prospective Effects of Violence Exposure across Multiple Contexts on Early Adolescents' Internalizing and Externalizing Problems

ERIC Educational Resources Information Center

Mrug, Sylvie; Windle, Michael

2010-01-01

Background: Violence exposure within each setting of community, school, or home has been linked with internalizing and externalizing problems. Although many children experience violence in multiple contexts, the effects of such cross-contextual exposure have not been studied. This study addresses this gap by examining independent and interactive…

Community Violence and Externalizing Problems: Moderating Effects of Race and Religiosity in Emerging Adulthood

ERIC Educational Resources Information Center

Fowler, Patrick J.; Ahmed, Sawssan R.; Tompsett, Carolyn J.; Jozefowicz-Simbeni, Debra M. H.; Toro, Paul A.

2008-01-01

The present study examined racial differences in the relationship between exposure to community violence and public and private religiosity in predicting externalizing problems among at-risk emerging adults. Participants were 178 African American and 163 European American emerging adults at risk for exposure to community violence. Exposure to…

Effects of long-range transported air pollution from vegetation fires on daily mortality and hospital admissions in the Helsinki metropolitan area, Finland.

PubMed

Kollanus, Virpi; Tiittanen, Pekka; Niemi, Jarkko V; Lanki, Timo

2016-11-01

Fine particulate matter (PM 2.5 ) emissions from vegetation fires can be transported over long distances and may cause significant air pollution episodes far from the fires. However, epidemiological evidence on health effects of vegetation-fire originated air pollution is limited, particularly for mortality and cardiovascular outcomes. We examined association between short-term exposure to long-range transported PM 2.5 from vegetation fires and daily mortality due to non-accidental, cardiovascular, and respiratory causes and daily hospital admissions due to cardiovascular and respiratory causes in the Helsinki metropolitan area, Finland. Days significantly affected by smoke from vegetation fires between 2001 and 2010 were identified using air quality measurements at an urban background and a regional background monitoring station, and modelled data on surface concentrations of vegetation-fire smoke. Associations between daily PM 2.5 concentration and health outcomes on i) smoke-affected days and ii) all other days (i.e. non-smoke days) were analysed using Poisson time series regression. All statistical models were adjusted for daily temperature and relative humidity, influenza, pollen, and public holidays. On smoke-affected days, 10µg/m 3 increase in PM 2.5 was associated with a borderline statistically significant increase in cardiovascular mortality among total population at a lag of three days (12.4%, 95% CI -0.2% to 26.5%), and among the elderly (≥65 years) following same-day exposure (13.8%, 95% CI -0.6% to 30.4%) and at a lag of three days (11.8%, 95% CI -2.2% to 27.7%). Smoke day PM 2.5 was not associated with non-accidental mortality or hospital admissions due to cardiovascular causes. However, there was an indication of a positive association with hospital admissions due to respiratory causes among the elderly, and admissions due to chronic obstructive pulmonary disease or asthma among the total population. In contrast, on non-smoke days PM 2.5 was generally not associated with the health outcomes, apart from suggestive small positive effects on non-accidental mortality at a lag of one day among the elderly and hospital admissions due to all respiratory causes following same-day exposure among the total population. Our research provides suggestive evidence for an association of exposure to long-range transported PM 2.5 from vegetation fires with increased cardiovascular mortality, and to a lesser extent with increased hospital admissions due to respiratory causes. Hence, vegetation-fire originated air pollution may have adverse effects on public health over a distance of hundreds to thousands of kilometres from the fires. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Quantitating Volatile Phenols in Cabernet Franc Berries and Wine after On-Vine Exposure to Smoke from a Simulated Forest Fire.

PubMed

Noestheden, Matthew; Dennis, Eric G; Zandberg, Wesley F

2018-01-24

Smoke-taint is a wine defect linked to organoleptic volatile phenols (VPs) in Vitis vinifera L. berries that have been exposed to smoke from wildland fires. Herein, the levels of smoke-taint-associated VPs are reported in Cabernet Franc berries from veraison to commercial maturity and in wine after primary fermentation following on-vine exposure to simulated wildland fire smoke. VPs increased after smoke exposure were rapidly stored as acid-labile conjugates, and the levels of both free VPs and conjugated forms remained constant through ripening to commercial maturity. An increase in total VPs after primary fermentation suggested the existence of VP-conjugates other than the acid-labile VP-glycosides already reported. This conclusion was supported with base hydrolysis on the same samples. Relative to published results, the data suggested a multifactorial regional identity for smoke-taint and they inform efforts to produce a predictive model for perceptible smoke-taint in wine based on the chemical composition of smoke-exposed berries.

Residual Tensile Strength and Bond Properties of GFRP Bars after Exposure to Elevated Temperatures.

PubMed

Ellis, Devon S; Tabatabai, Habib; Nabizadeh, Azam

2018-02-27

The use of fiber reinforced polymer (FRP) bars in reinforced concrete members enhances corrosion resistance when compared to traditional steel reinforcing bars. Although there is ample research available on the behavior of FRP bars and concrete members reinforced with FRP bars under elevated temperatures (due to fire), there is little published information available on their post-fire residual load capacity. This paper reports residual tensile strength, modulus of elasticity, and bond strength (to concrete) of glass fiber reinforced polymer (GFRP) bars after exposure to elevated temperatures of up to 400 °C and subsequent cooling to an ambient temperature. The results showed that the residual strength generally decreases with increasing temperature exposure. However, as much as 83% of the original tensile strength and 27% of the original bond strength was retained after the specimens were heated to 400 °C and then cooled to ambient temperature. The residual bond strength is a critical parameter in post-fire strength assessments of GFRP-reinforced concrete members.

Residual Tensile Strength and Bond Properties of GFRP Bars after Exposure to Elevated Temperatures

PubMed Central

Ellis, Devon S.

2018-01-01

The use of fiber reinforced polymer (FRP) bars in reinforced concrete members enhances corrosion resistance when compared to traditional steel reinforcing bars. Although there is ample research available on the behavior of FRP bars and concrete members reinforced with FRP bars under elevated temperatures (due to fire), there is little published information available on their post-fire residual load capacity. This paper reports residual tensile strength, modulus of elasticity, and bond strength (to concrete) of glass fiber reinforced polymer (GFRP) bars after exposure to elevated temperatures of up to 400 °C and subsequent cooling to an ambient temperature. The results showed that the residual strength generally decreases with increasing temperature exposure. However, as much as 83% of the original tensile strength and 27% of the original bond strength was retained after the specimens were heated to 400 °C and then cooled to ambient temperature. The residual bond strength is a critical parameter in post-fire strength assessments of GFRP-reinforced concrete members. PMID:29495489

Parametric Study of Fire Performance of Concrete Filled Hollow Steel Section Columns with Circular and Square Cross-Section

NASA Astrophysics Data System (ADS)

Nurfaidhi Rizalman, Ahmad; Tahir, Ng Seong Yap Mahmood Md; Mohammad, Shahrin

2018-03-01

Concrete filled hollow steel section column have been widely accepted by structural engineers and designers for high rise construction due to the benefits of combining steel and concrete. The advantages of concrete filled hollow steel section column include higher strength, ductility, energy absorption capacity, and good structural fire resistance. In this paper, comparison on the fire performance between circular and square concrete filled hollow steel section column is established. A three-dimensional finite element package, ABAQUS, was used to develop the numerical model to study the temperature development, critical temperature, and fire resistance time of the selected composite columns. Based on the analysis and comparison of typical parameters, the effect of equal cross-sectional size for both steel and concrete, concrete types, and thickness of external protection on temperature distribution and structural fire behaviour of the columns are discussed. The result showed that concrete filled hollow steel section column with circular cross-section generally has higher fire resistance than the square section.

Exposure to wood smoke particles produces an inflammation in healthy volunteers

EPA Science Inventory

Background. Human exposure to wood smoke particles (WSP) is of consequence in indoor air quality, exposures from wild fires, burning ofbiomass, and air pollution. This investigation tested the postulate that healthy volunteers exposed to WSP would demonstrate pulmonary and cardio...

Exposure to Violence and Socioemotional Adjustment in Low-Income Youth: An Examination of Protective Factors

PubMed Central

Hardaway, Cecily R.; McLoyd, Vonnie C.; Wood, Dana

2014-01-01

Using a sample of 391 low-income youth ages 13 to 17, this study investigated the potential moderating effects of school climate, participation in extracurricular activities, and positive parent-child relations on associations between exposure to violence (i.e., witnessing violence and violent victimization) and adolescent socioemotional adjustment (i.e., internalizing and externalizing problems). Exposure to violence was related to both internalizing and externalizing problems. High levels of participation in extracurricular activities and positive parent-child relations appeared to function as protective factors, weakening the positive association between exposure to violence and externalizing problems. Contrary to prediction, school climate did not moderate associations between exposure to violence and socioemotional adjustment. Further, none of the hypothesized protective factors moderated the association between exposure to violence and internalizing problems. PMID:21607826

Malignant mesothelioma

MedlinePlus

... abdomen (peritoneum). It is due to long-term asbestos exposure. ... Long-term exposure to asbestos is the biggest risk factor. Asbestos is a fire-resistant material. It was once commonly found in insulation, ceiling and ...

Smoke exposure among firefighters at prescribed burns in the Pacific Northwest.

Treesearch

Timothy E. Reinhardt; Roger D. Ottmar; Andrew J.S. Hanneman

2000-01-01

Smoke exposure measurements among firefighters during prescribed burns in the Pacific Northwest between 1991 and 1994 showed that a small but significant percentage of workers experienced exposure to carbon monoxide and respiratory irritants that exceeded occupational exposure limits. This most often was caused by unfavorable winds or fire behavior and occurred mostly...

[Fire worship on Soratte: form prehistory to present days].

PubMed

Falchetti, Mario; Ottini, Laura

2013-01-01

Fire has always been involved in human thoughts, believes and actions. For many psychological reasons fire has been considered as living power: red as the human blood, warm as the human body, clearly shines in the night. Fire worship is very common, especially in regions where terrestrial fire is believed to be the image of the heavenly fire. Fire worship has represented the base for symbolic systems involved in the cultural-anthropological evolution of populations settled close to mount Soratte. Fire cults in this region have originated in independent and long-time separated contexts, according to available knowledge. Hirpi Sorani, ancient inhabitants of mount Soratte territory, celebrated Sorano Apollo by a famous fire walking ceremony, with a likely cathartic and apotropaic meaning, as reported by ancient Roman writers. The victory of Christianity over paganism caused the decline of these religious practices. The beginning of the XIX century witnessed the establishment ofa new kind of devotion to the Virgin Mary at the mount Soratte. Today, this religious piety-linked identity has weakened due to changes in lifestyles,from an agricultural to one based on outside home employment, and has been largely shifted on cultural and anthropological bases. In conclusion, fire worship at mount Soratte has evolved because of external influences and local inhabitants have reacted by asserting their own identity.

Mercury risk assessment combining internal and external exposure methods for a population living near a municipal solid waste incinerator.

PubMed

Deng, Chunyan; Xie, Han; Ye, Xuejie; Zhang, Haoran; Liu, Maodian; Tong, Yindong; Ou, Langbo; Yuan, Wen; Zhang, Wei; Wang, Xuejun

2016-12-01

Risk assessments for human health have been conducted for municipal solid waste incinerators (MSWIs) in many western countries, whereas only a few risk assessments have been performed for MSWIs in developing countries such as China where the use of waste incineration is increasing rapidly. To assess the mercury exposure risks of a population living near the largest MSWI in South China, we combined internal exposure and external exposure assessment with an individual-specific questionnaire. The mercury concentrations in air, soil, and locally collected food around the MSWI were assessed. The total mercury (T-Hg) and methylmercury (MeHg) of 447 blood samples from a control group, residential exposure group, and MSWI workers were measured. The internal and external exposures of the subject population were analyzed. Significant difference in MeHg concentrations was observed between the control group and the exposed group, between the control group and the MSWI workers, and between the exposed group and the MSWI workers (median levels: 0.70 μg/L, 0.81 μg/L, and 1.02 μg/L for the control group, exposed group, and MSWI workers, respectively). The MeHg/T-Hg ratio was 0.51 ± 0.19, 0.59 ± 0.17 and 0.58 ± 0.25, respectively. Multiple linear regression analysis indicated that MeHg concentrations were positively correlated with the gaseous mercury in the air. Combining internal and external exposure assessment showed that the direct contribution of MSWI emissions was minor compared with the dietary contribution. The external and internal exposures were well matched with each other. This study also suggested that an integrated method combining internal and external exposure assessment with an individual-specific questionnaire is feasible to assess the risks for a population living near a MSWI. Copyright © 2016 Elsevier Ltd. All rights reserved.

Persistence of external signs in Pacific herring Clupea pallasii Valenciennes with ichthyophoniasis

USGS Publications Warehouse

Hart, Lucas M.; Conway, Carla M.; Elliott, Diane G.; Hershberger, Paul K.

2016-01-01

The progression of external signs of Ichthyophonus infection in Pacific herring Clupea pallasii Valenciennes was highly variable and asynchronous after intraperitoneal injection with pure parasite preparations; however, external signs generally persisted through the end of the study (429 days post-exposure). Observed signs included papules, erosions and ulcers. The prevalence of external signs plateaued 35 days post-exposure and persisted in 73–79% of exposed individuals through the end of the first experiment (147 days post-exposure). Among a second group of infected herring, external signs completely resolved in only 10% of the fish after 429 days. The onset of mortality preceded the appearance of external signs. Histological examination of infected skin and skeletal muscle tissues indicated an apparent affinity of the parasite for host red muscle. Host responses consisted primarily of granulomatous inflammation, fibrosis and necrosis in the skeletal muscle and other tissues. The persistence and asynchrony of external signs and host response indicated that they were neither a precursor to host mortality nor did they provide reliable metrics for hindcasting on the date of exposure. However, the long-term persistence of clinical signs in Pacific herring may be useful in ascertaining the population-level impacts of ichthyophoniasis in regularly observed populations.

Polycyclic aromatic hydrocarbons at fire stations: firefighters' exposure monitoring and biomonitoring, and assessment of the contribution to total internal dose.

PubMed

Oliveira, Marta; Slezakova, Klara; Alves, Maria José; Fernandes, Adília; Teixeira, João Paulo; Delerue-Matos, Cristina; Pereira, Maria do Carmo; Morais, Simone

2017-02-05

This work characterizes levels of eighteen polycyclic aromatic hydrocarbons (PAHs) in the breathing air zone of firefighters during their regular work shift at eight Portuguese fire stations, and the firefighters' total internal dose by six urinary monohydroxyl metabolites (OH-PAHs). Total PAHs (ΣPAHs) concentrations varied widely (46.4-428ng/m 3 ), mainly due to site specificity (urban/rural) and characteristics (age and layout) of buildings. Airborne PAHs with 2-3 rings were the most abundant (63.9-95.7% ΣPAHs). Similarly, urinary 1-hydroxynaphthalene and 1-hydroxyacenaphthene were the predominant metabolites (66-96% ΣOH-PAHs). Naphthalene contributed the most to carcinogenic ΣPAHs (39.4-78.1%) in majority of firehouses; benzo[a]pyrene, the marker of carcinogenic PAHs, accounted with 1.5-10%. Statistically positive significant correlations (r≥0.733, p≤0.025) were observed between ΣPAHs and urinary ΣOH-PAHs for firefighters of four fire stations suggesting that, at these sites, indoor air was their major exposure source of PAHs. Firefighter's personal exposure to PAHs at Portuguese fire stations were well below the existent occupational exposure limits. Also, the quantified concentrations of post-shift urinary 1-hydroxypyrene in all firefighters were clearly lower than the benchmark level (0.5μmol/mol) recommended by the American Conference of Governmental Industrial Hygienists. Copyright © 2016 Elsevier B.V. All rights reserved.

No neurochemical evidence of brain injury after blast overpressure by repeated explosions or firing heavy weapons.

PubMed

Blennow, K; Jonsson, M; Andreasen, N; Rosengren, L; Wallin, A; Hellström, P A; Zetterberg, H

2011-04-01

Psychiatric and neurological symptoms are common among soldiers exposed to blast without suffering a direct head injury. It is not known whether such symptoms are direct consequences of blast overpressure. To examine if repeated detonating explosions or firing if of heavy weapons is associated with neurochemical evidence of brain damage. Three controlled experimental studies. In the first, army officers were exposed to repeated firing of a FH77B howitzer or a bazooka. Cerebrospinal fluid (CSF) was taken post-exposure to measure biomarkers for brain damage. In the second, officers were exposed for up to 150 blasts by firing a bazooka, and in the third to 100 charges of detonating explosives of 180 dB. Serial serum samples were taken after exposure. Results were compared with a control group consisting of 19 unexposed age-matched healthy volunteers. The CSF biomarkers for neuronal/axonal damage (tau and neurofilament protein), glial cell injury (GFAP and S-100b), blood-brain barrier damage (CSF/serum albumin ratio) and hemorrhages (hemoglobin and bilirubin) and the serum GFAP and S-100b showed normal and stable levels in all exposed officers. Repeated exposure to high-impact blast does not result in any neurochemical evidence of brain damage. These findings are of importance for soldiers regularly exposed to high-impact blast when firing artillery shells or other types of heavy weapons. © 2010 John Wiley & Sons A/S.

Investigation of occupational radiation exposures to NORM at an Irish peat-fired power station and potential use of peat fly ash by the construction industry.

PubMed

Organo, C; Lee, E M; Menezes, G; Finch, E C

2005-12-01

Annually, approximately 15% of Ireland's electricity requirement is provided through the combustion of 3 x 10(6) tonnes of peat. While the literature on coal-fired power generation is quite abundant, studies on the peat-fired power generation industry from a radiological point of view are scarce. A study of the largest Irish peat-fired power plant was initiated to review the potential occupational radiation exposures arising from the occurrence of naturally occurring radioactive material (NORM) at different stages of the industrial process and to investigate any radiological health consequences that may arise should peat fly ash be used as a component of building materials. Ambient gamma dose rate measurements, radon measurements, quantification of the occupational exposure from inhalation of airborne particles (personal air sampling) and gamma spectrometry analysis of peat, peat ash and effluent samples from the ash ponds were undertaken. The results indicate that the radiation dose received by any worker involved in the processing of the peat and the handling of the ash resulting from peat combustion does not exceed 150 microSv per annum. Regulatory control of the peat-fired power generation is therefore unnecessary according to the Irish legislation with regards to NORM. The potential use of peat fly ash as a by-product in the building industry was also found to have a negligible radiological impact for construction workers and for members of the public.

The Effects of Child Abuse and Exposure to Domestic Violence on Adolescent Internalizing and Externalizing Behavior Problems.

PubMed

Moylan, Carrie A; Herrenkohl, Todd I; Sousa, Cindy; Tajima, Emiko A; Herrenkohl, Roy C; Russo, M Jean

2010-01-01

This study examines the effects of child abuse and domestic violence exposure in childhood on adolescent internalizing and externalizing behaviors. Data for this analysis are from the Lehigh Longitudinal Study, a prospective study of 457 youth addressing outcomes of family violence and resilience in individuals and families. Results show that child abuse, domestic violence, and both in combination (i.e., dual exposure) increase a child's risk for internalizing and externalizing outcomes in adolescence. When accounting for risk factors associated with additional stressors in the family and surrounding environment, only those children with dual exposure had an elevated risk of the tested outcomes compared to non-exposed youth. However, while there were some observable differences in the prediction of outcomes for children with dual exposure compared to those with single exposure (i.e., abuse only or exposure to domestic violence only), these difference were not statistically significant. Analyses showed that the effects of exposure for boys and girls are statistically comparable.

A General Model of Dioxin Contamination in Breast Milk: Results from a Study on 94 Women from the Caserta and Naples Areas in Italy

PubMed Central

Rivezzi, Gaetano; Piscitelli, Prisco; Scortichini, Giampiero; Giovannini, Armando; Diletti, Gianfranco; Migliorati, Giacomo; Ceci, Roberta; Rivezzi, Giulia; Cirasino, Lorenzo; Carideo, Pietro; Black, Dennis M.; Garzillo, Carmine; Giani, Umberto

2013-01-01

Background: The Caserta and Naples areas in Campania Region experience heavy environmental contamination due to illegal waste disposal and burns, thus representing a valuable setting to develop a general model of human contamination with dioxins (PCDDs-PCDFs) and dioxin-like-PCBs (dl-PCBs). Methods: 94 breastfeeding women (aged 19–32 years; mean age 27.9 ± 3.0) were recruited to determine concentrations of PCDDs-PCDFs and dl-PCBs in their milk. Individual milk samples were collected and analyzed according to standard international procedures. A generalized linear model was used to test potential predictors of pollutant concentration in breast milk: age, exposure to waste fires, cigarette smoking, diet, and residence in high/low risk area (defined at high/low environmental pressure by a specific 2007 WHO report). A Structural Equation Model (SEM) analysis was carried out by taking into account PCDDs-PCDFs and dl-PCBs as endogenous variables and age, waste fires, risk area and smoking as exogenous variables. Results: All milk samples were contaminated by PCDDs-PCDFs (8.6 pg WHO-TEQ/98g fat ± 2.7; range 3.8–19) and dl-PCBs (8.0 pg WHO-TEQ/98g fat ± 3.7; range 2.5–24), with their concentrations being associated with age and exposure to waste fires (p < 0.01). Exposure to fires resulted in larger increases of dioxins concentrations in people living in low risk areas than those from high risk areas (p < 0.01). Conclusions: A diffuse human exposure to persistent organic pollutants was observed in the Caserta and Naples areas. Dioxins concentration in women living in areas classified at low environmental pressure in 2007 WHO report was significantly influenced by exposure to burns. PMID:24217180

Assessing Transboundary Wildfire Exposure in the Southwestern United States.

PubMed

Ager, Alan A; Palaiologou, Palaiologos; R Evers, Cody; Day, Michelle A; G Barros, Ana M

2018-04-25

We assessed transboundary wildfire exposure among federal, state, and private lands and 447 communities in the state of Arizona, southwestern United States. The study quantified the relative magnitude of transboundary (incoming, outgoing) versus nontransboundary (i.e., self-burning) wildfire exposure based on land tenure or community of the simulated ignition and the resulting fire perimeter. We developed and described several new metrics to quantify and map transboundary exposure. We found that incoming transboundary fire accounted for 37% of the total area burned on large parcels of federal and state lands, whereas 63% of the area burned was burned by ignitions within the parcel. However, substantial parcel to parcel variation was observed for all land tenures for all metrics. We found that incoming transboundary fire accounted for 66% of the total area burned within communities versus 34% of the area burned by self-burning ignitions. Of the total area burned within communities, private lands contributed the largest proportion (36.7%), followed by national forests (19.5%), and state lands (15.4%). On average seven land tenures contributed wildfire to individual communities. Annual wildfire exposure to structures was highest for wildfires ignited on state and national forest land, followed by tribal, private, and BLM. We mapped community firesheds, that is, the area where ignitions can spawn fires that can burn into communities, and estimated that they covered 7.7 million ha, or 26% of the state of Arizona. Our methods address gaps in existing wildfire risk assessments, and their implementation can help reduce fragmentation in governance systems and inefficiencies in risk planning. Published 2018. This article is a U.S. government work and is in the public domain in the USA.

Fire scar growth and closure rates in white oak (Quercus alba) and the implications for prescribed burning

Treesearch

Michael C. Stambaugh; Kevin T. Smith; Daniel C. Dey

2017-01-01

In burned forestlands, fire scar wounds commonly occur on tree stems as a result of cambial heating. In hardwood forests in particular, wounding can lead to stem decay with the extent of decay being related to scar size and exposure time. Therefore, wound closure rates are important to understand in the context of fire management such that allowing sufficient time for...

Apparatus and methodology for fire gas characterization by means of animal exposure

NASA Technical Reports Server (NTRS)

Marcussen, W. H.; Hilado, C. J.; Furst, A.; Leon, H. A.; Kourtides, D. A.; Parker, J. A.; Butte, J. C.; Cummins, J. M.

1976-01-01

While there is a great deal of information available from small-scale laboratory experiments and for relatively simple mixtures of gases, considerable uncertainty exists regarding appropriate bioassay techniques for the complex mixture of gases generated in full-scale fires. Apparatus and methodology have been developed based on current state of the art for determining the effects of fire gases in the critical first 10 minutes of a full-scale fire on laboratory animals. This information is presented for its potential value and use while further improvements are being made.

Prenatal Exposure to Perfluoroalkyl Substances and Behavioral Development in Children.

PubMed

Quaak, Ilona; de Cock, Marijke; de Boer, Michiel; Lamoree, Marja; Leonards, Pim; van de Bor, Margot

2016-05-19

In recent years, prevalence rates of behavioral disorders in children have increased. One factor possibly implied in the etiology of behavioral disorders is exposure to perfluoroalkyl substances (PFASs). The use of PFASs is highly integrated into everyday life, and exposure is ubiquitous. Exposure to PFASs during early life may be particularly harmful, as it represents a critical time window for brain development. However, research in the area is limited, especially among preschool children. The objective of the current study was to explore the relationship between prenatal exposure to several PFASs and behavioral development at the age of 18 months. Data from the Dutch cohort LINC (Linking Maternal Nutrition to Child Health) were used. Perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA) were measured in cord plasma. The total exposure of PFASs was also calculated (ΣPFASs). Behavioral development was assessed with the Child Behavior Checklist 1.5-5 (CBCL 1.5-5). The CBCL scales "Attention Deficit Hyperactivity Disorder" (ADHD) and "Externalizing problems" were used for further analysis. Separate regression models were composed for each combination, in which exposure levels were classified in tertiles. Both whole population and sex-stratified analyses were performed. A family history of ADHD, the educational level, smoking or using alcohol or illicit drugs during pregnancy were considered as confounders. In total, data from 76 mother-child pairs was included. No significant associations were found between prenatal PFAS exposure and ADHD scores in the whole population and in the sex-stratified analyses. With regard to externalizing behavior, a significant negative association was found between the highest levels of ΣPFAS exposure and externalizing problem behavior in the whole population, but only in the crude model. After stratifying for sex, boys in the second and third tertile of exposure to PFOA presented significantly lower scores on the Externalizing Problem Scale than boys with the lowest exposure levels in the adjusted model. Girls exposed to higher levels of ΣPFAS exposure (T2) showed significantly lower scores on the Externalizing Problem Scale, in both crude and adjusted models. No significant associations with PFOS were found. RESULTS from the current study show that prenatal exposure to PFOA was negatively related to externalizing behavior in boys. RESULTS were different for boys and girls, emphasizing that mechanisms at work might be sex-dependent. However, results should be interpreted with caution as the sample size was small.

Mine fire experiments and simulation with MFIRE

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

Laage, L.W.; Yang, Hang

1995-12-31

A major concern of mine fires is the heat generated ventilation disturbances which can move products of combustion (POC) through unexpected passageways. Fire emergency planning requires simulation of the interaction of the fire and ventilation system to predict the state of the ventilation system and the subsequent distribution of temperatures and POC. Several computer models were developed by the U.S. Bureau of Mines (USBM) to perform this simulation. The most recent, MFIRE, simulates a mine`s ventilation system and its response to altered ventilation parameters such as the development of new mine workings or changes in ventilation control structures, external influencemore » such as varying outside temperatures, and internal influences such as fires. Extensive output allows quantitative analysis of the effects of the proposed alteration to die ventilation system. This paper describes recent USBM research to validate MFIRE`s calculation of temperature distribution in an airway due to a mine fire, as temperatures are the most significant source of ventilation disturbances. Fire tests were conducted at the Waldo Mine near Magdalena, NM. From these experiments, temperature profiles were developed as functions of time and distance from the fire and compared with simulations from MFIRE.« less

Health Effects of the 2003 Southern California Wildfires on Children

PubMed Central

Künzli, Nino; Avol, Ed; Wu, Jun; Gauderman, W. James; Rappaport, Ed; Millstein, Joshua; Bennion, Jonathan; McConnell, Rob; Gilliland, Frank D.; Berhane, Kiros; Lurmann, Fred; Winer, Arthur; Peters, John M.

2006-01-01

Rationale: In late October 2003, Southern California wildfires burned more than 3,000 km2. The wildfires produced heavy smoke that affected several communities participating in the University of Southern California Children's Health Study (CHS). Objectives: To study the acute effects of fire smoke on the health of CHS participants. Methods: A questionnaire was used to assess smoke exposure and occurrence of symptoms among CHS high-school students (n = 873; age, 17–18 yr) and elementary-school children (n = 5,551; age, 6–7 yr), in a total of 16 communities. Estimates of particulate matter (PM10) concentrations during the 5 d with the highest fire activity were used to characterize community smoke level. Main Results: All symptoms (nose, eyes, and throat irritations; cough; bronchitis; cold; wheezing; asthma attacks), medication usage, and physician visits were associated with individually reported exposure differences within communities. Risks increased monotonically with the number of reported smoky days. For most outcomes, reporting rates between communities were also associated with the fire-related PM10 levels. Associations tended to be strongest among those without asthma. Individuals with asthma were more likely to take preventive action, such as wearing masks or staying indoors during the fire. Conclusions: Exposure to wildfire smoke was associated with increased eye and respiratory symptoms, medication use, and physician visits. PMID:16946126

Health effects of the 2003 Southern California wildfires on children.

PubMed

Künzli, Nino; Avol, Ed; Wu, Jun; Gauderman, W James; Rappaport, Ed; Millstein, Joshua; Bennion, Jonathan; McConnell, Rob; Gilliland, Frank D; Berhane, Kiros; Lurmann, Fred; Winer, Arthur; Peters, John M

2006-12-01

In late October 2003, Southern California wildfires burned more than 3,000 km2. The wildfires produced heavy smoke that affected several communities participating in the University of Southern California Children's Health Study (CHS). To study the acute effects of fire smoke on the health of CHS participants. A questionnaire was used to assess smoke exposure and occurrence of symptoms among CHS high-school students (n = 873; age, 17-18 yr) and elementary-school children (n = 5,551; age, 6-7 yr), in a total of 16 communities. Estimates of particulate matter (PM10) concentrations during the 5 d with the highest fire activity were used to characterize community smoke level. All symptoms (nose, eyes, and throat irritations; cough; bronchitis; cold; wheezing; asthma attacks), medication usage, and physician visits were associated with individually reported exposure differences within communities. Risks increased monotonically with the number of reported smoky days. For most outcomes, reporting rates between communities were also associated with the fire-related PM10 levels. Associations tended to be strongest among those without asthma. Individuals with asthma were more likely to take preventive action, such as wearing masks or staying indoors during the fire. Exposure to wildfire smoke was associated with increased eye and respiratory symptoms, medication use, and physician visits.

Outbreak of cryptosporidiosis associated with a firefighting response - Indiana and Michigan, June 2011.

PubMed

2012-03-09

On June 20, 2011, the Indiana Department of Homeland Security notified the Indiana State Department of Health (ISDH) of an Indiana fire station that reported gastrointestinal illness among a substantial percentage of their workers, causing missed workdays and one hospitalization as a result of cryptosporidiosis. All ill firefighters had responded to a barn fire in Michigan, 15 miles from the Michigan-Indiana border on June 6; responding firefighters from Michigan also had become ill. ISDH immediately contacted the Michigan Department of Community Health (MDCH) concerning this outbreak. The investigation was led by MDCH in partnership with ISDH and the Michigan local health department (LHD). Among 34 firefighters who responded to the fire, 33 were interviewed, and 20 (61%) reported gastrointestinal illness ≤12 days after the fire. Cryptosporidium parvum was identified in human stool specimens, calf fecal samples, and a swimming pond. Based on these findings, the following public health recommendations were issued: 1) discontinue swimming in the pond, 2) practice thorough hygiene to reduce fecal contamination and fecal-oral exposures, and 3) decontaminate firefighting equipment properly. No additional primary or secondary cases associated with this exposure have been reported. The findings highlight a novel work-related disease exposure for firefighters and the need for public education regarding cryptosporidiosis prevention.

Incorporation of additional radionuclides and the external exposure pathway into the BECAMP (Basic Environmental Compliance and Monitoring Program) radiological assessment model

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

Ng, Yook C.; Rodean, H.C.; Anspaugh, L.R.

The Nevada Applied Ecology Group (NAEG) Model of transport and dose for transuranic radionuclides was modified and expanded for the analysis of radionuclides other than pure alpha-emitters. Doses from internal and external exposures were estimated for the inventories and soil distributions of the individual radionuclides quantified in Areas 2 and 4 of the Nevada Test Site (NTS). We found that the dose equivalents via inhalation to liver, lungs, bone marrow, and bone surface from the plutonium isotopes and /sup 241/Am, those via ingestion to bone marrow and bone surfaces from /sup 90/Sr, and those via ingestion to all the targetmore » organs from /sup 137/Cs were the highest from internal exposures. The effective dose equivalents from /sup 137/Cs, /sup 152/Eu, and /sup 154/Eu were the highest from the external exposures. The /sup 60/Co, /sup 152/Eu, /sup 154/Eu, and /sup 155/Eu dose estimates for external exposures greatly exceeded those for internal exposures. The /sup 60/Co, /sup 90/Sr, and /sup 137/Cs dose equivalents from internal exposures were underestimated due to the adoption of some of the foodchain parameter values originally selected for /sup 239/Pu. Nonetheless, the ingestion pathway contributed significantly to the dose estimates for /sup 90/Sr and /sup 137/Cs, but contributed very much less than external exposures to the dose estimates for /sup 60/Co. Therefore, the use of more appropriate values would not alter the identification of important radionuclides, pathways, target organs, and exposure modes in this analysis. 19 refs., 13 figs., 12 tabs.« less

Prototypic and Arkypallidal Neurons in the Dopamine-Intact External Globus Pallidus

PubMed Central

Abdi, Azzedine; Mallet, Nicolas; Mohamed, Foad Y.; Sharott, Andrew; Dodson, Paul D.; Nakamura, Kouichi C.; Suri, Sana; Avery, Sophie V.; Larvin, Joseph T.; Garas, Farid N.; Garas, Shady N.; Vinciati, Federica; Morin, Stéphanie; Bezard, Erwan

2015-01-01

Studies in dopamine-depleted rats indicate that the external globus pallidus (GPe) contains two main types of GABAergic projection cell; so-called “prototypic” and “arkypallidal” neurons. Here, we used correlative anatomical and electrophysiological approaches in rats to determine whether and how this dichotomous organization applies to the dopamine-intact GPe. Prototypic neurons coexpressed the transcription factors Nkx2-1 and Lhx6, comprised approximately two-thirds of all GPe neurons, and were the major GPe cell type innervating the subthalamic nucleus (STN). In contrast, arkypallidal neurons expressed the transcription factor FoxP2, constituted just over one-fourth of GPe neurons, and innervated the striatum but not STN. In anesthetized dopamine-intact rats, molecularly identified prototypic neurons fired at relatively high rates and with high regularity, regardless of brain state (slow-wave activity or spontaneous activation). On average, arkypallidal neurons fired at lower rates and regularities than prototypic neurons, and the two cell types could be further distinguished by the temporal coupling of their firing to ongoing cortical oscillations. Complementing the activity differences observed in vivo, the autonomous firing of identified arkypallidal neurons in vitro was slower and more variable than that of prototypic neurons, which tallied with arkypallidal neurons displaying lower amplitudes of a “persistent” sodium current important for such pacemaking. Arkypallidal neurons also exhibited weaker driven and rebound firing compared with prototypic neurons. In conclusion, our data support the concept that a dichotomous functional organization, as actioned by arkypallidal and prototypic neurons with specialized molecular, structural, and physiological properties, is fundamental to the operations of the dopamine-intact GPe. PMID:25926446

The health impacts and economic value of wildland fire episodes in the U.S.: 2008-2012

EPA Science Inventory

Introduction: Wildland fires degrade regional air quality and adversely affect human health. A growing body of epidemiology literature report increased rates of emergency department, hospital admission and premature deaths from wildfire smoke exposure. Objective: Our research a...

Test results from a comparative evaluation of a condensation nuclei fire detector

NASA Technical Reports Server (NTRS)

Bricker, R. W.

1985-01-01

The fire/smoke alarm response of a condensation nuclei fire detector (CNFD) was compared with photoelectric and ionization detectors. Tests were conducted in a former control room 8.5 m by 8.9 with a 2.7 m ceiling. The room had air supplied from above the ceiling and under the floor with return air exiting from ceiling grills. The environment was varied from 278 to 305 K and relative humidities from 8 to 65%. Four detection zones were located in the room. Each zone contained a sampling head for the CNDF, a photodetector, and an ionization detector so that each detector system had four opportunities to alarm during tests. The particle level in the test room was also monitored during tests with a condensation nuclei particle counter. The CNFD responded to 90% of exposures to smoldering plastic and 84% of exposures to visible fire. The photoelectric response was 43 and 12.5% respectively for the same conditions. The ionization response was 9 and 48 respectively.

Space Station as a Long Duration Exposure Facility

NASA Technical Reports Server (NTRS)

Folley, Adrienne; Scheib, Jim

1995-01-01

There is need for a space platform for experiments investigating long duration exposure to space. This platform should be maintainable in the event of a malfunction, and experiments should be easily recoverable for analysis on Earth. The International Space Station provides such a platform. The current Space Station configuration has six external experiment attachment sites, providing utilities and data support distributed along the external truss. There are also other sites that could potentially support long duration exposure experiments. This paper describes the resources provided to payloads at these sites, and cites examples of integration of proposed long duration exposure experiments on these sites. The environments to which external attached payloads will be exposed are summarized.

Materials for fire resistant passenger seats in aircraft

NASA Technical Reports Server (NTRS)

Tesoro, G.; Moussa, A.

1980-01-01

The paper considers the selection of cushioning foam and upholstery fabric materials for aircraft passenger seats. Polyurethane, polychloroprene, polyimide, and polyphosphazene are the foam materials considered; and a variety of commercial and developmental fabrics (including wool, cotton, synthetics, and blends) are examined. Viable approaches to the design of fire-resistant seat assemblies are indicated. Results of an experimental laboratory study of fabrics and fabric/foam assemblies exposed to external point-source radiative heat flux are discussed.

ELECTROPHYSIOLOGY OF ELECTRIC ORGAN IN GYMNOTUS CARAPO

PubMed Central

Bennett, Michael V. L.; Grundfest, Harry

1959-01-01

The electric organ of G. carapo is formed by linearly arrayed electroplaques which lie in four tubes on each side of the fish. In one tube the electroplaques are innervated on their rostral surfaces, in the others on the caudal. Both surfaces of each electroplaque produce spikes, and either can be excited alone by a suitably oriented externally applied stimulating current. The innervated surface, however, has a lower threshold, and in the normal organ activity, which is a continuous discharge at 35 to 60/sec., it is always fired first by the large neurally evoked postsynaptic potential. The spike of the innervated face then fires the opposite face. The potential recorded external to the innervated face is initially negative and becomes positive when the other face fires. The potential outside the other face is inverted. The p.s.p.'s are electrically inexcitable, have short duration, and are augmented by hyperpolarization. A single electroplaque is innervated by several nerve fibers, which produce summative p.s.p.'s. Homosynaptic facilitation of p.s.p.'s is common. The synapses are cholinoceptive. The organ discharge begins with synchronized activity in the rostrally innervated electroplaques. After a brief interval, the electroplaques in the other three tubes fire. The organ discharge therefore is triphasic, resulting from the summation of the two diphasic components that are oppositely directed and asynchronous. Observations on the sensory role of the organ are included. PMID:13654750

Internal, external and location factors influencing cofiring of biomass with coal in the U.S. northern region

Treesearch

Francisco X. Aguilar; Michael E. Goerndt; Nianfu Song; Stephen R. Shifley

2012-01-01

The use of biomass as a source of energy has been identified as a viable option to diminish reliance on fossil fuels. We parameterized the effect of selected internal (e.g. coal-fire presence), external (e.g. price and renewable energy mandates) and location (e.g. biomass availability, infrastructure) variables on the likelihood of using biomass in cofiring with coal...

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

A closeup reveals the loose bracket, observed hanging down from the side of the White Room at Launch Pad 39B, that delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

Electrical Cabinet Fire Extinguishment Testing

DTIC Science & Technology

2014-12-01

Ins t series thes for the majo of soot (alth lenses in the arbon steel, re exposure ests. of each me cabinet (at aried with h above the above...ressure in th g pre-burn, 1 2 titute of Swe et was monit presented in Figure 19. re measured ssure sensor . be made con ssure in the e reduced the e...preven e of the extin r than the ov r pressure in opped to a n titute of Swe ra 25, was s ting pre-fire he major dif soot (despit exposure. in

Is received dose from ingested soil independent of soil PAH concentrations?-Animal model results.

PubMed

Peters, Rachel E; James, Kyle; Cave, Mark; Wickstrom, Mark; Siciliano, Steven D

2016-09-01

Polycyclic aromatic hydrocarbon (PAH) bioavailability from ingested soils will vary between soils; however, the nature of this variation is not well characterized. A juvenile swine model was used to link external exposure to internal benzo[a]pyrene (BaP) and anthracene exposure following oral PAH ingestion of 27 different impacted site soils, soots, or spiked artificial soils. Internal exposure of BaP and anthracene, represented by area under the plasma-time curve, did not relate to soil concentration in impacted site soils, but did relate in spiked artificial soil. Point of departure modeling identified soil PAH concentrations greater than 1900 mg kg(-1) as the point where area under the curve becomes proportional to external dose. A BaP internal exposure below 1900 mg kg(-1) had an upper 95% confidence interval estimate of 33% of external exposure. Weak relationships between soil:simulated gastrointestinal fluid PAH partitioning and area under the curve values suggest that differences in internal PAH exposure between soils may not be dominated by differences in PAH partitioning. The data seem to best support exposure assessment assuming constant internal PAH exposure below soil concentrations of 1900 mg kg(-1) . However, because constant internal exposure would challenge several existing paradigms, a bioavailability estimate of 33% of the external exposure is suggested as a likely workable solution. Environ Toxicol Chem 2016;35:2261-2269. © 2016 SETAC. © 2016 SETAC.

Smoke Ready Toolbox for Wildfires

EPA Pesticide Factsheets

This site provides an online Smoke Ready Toolbox for Wildfires, which lists resources and tools that provide information on health impacts from smoke exposure, current fire conditions and forecasts and strategies to reduce exposure to smoke.

Respiratory symptoms following wildfire smoke exposure: airway size as a susceptibility factor.

PubMed

Mirabelli, Maria C; Künzli, Nino; Avol, Edward; Gilliland, Frank D; Gauderman, W James; McConnell, Rob; Peters, John M

2009-05-01

Associations between exposure to smoke during wildfire events and respiratory symptoms are well documented, but the role of airway size remains unclear. We conducted this analysis to assess whether small airway size modifies these relationships. We analyzed data from 465 nonasthmatic 16- to 19-year-old participants in the Children's Health Study. Following an outbreak of wildfires in 2003, each student completed a questionnaire about smoke exposure, dry and wet cough, wheezing, and eye symptoms. We used log-binomial regression to evaluate associations between smoke exposure and fire-related health symptoms, and to assess modification of the associations by airway size. As a marker of airway size, we used the ratio of maximum midexpiratory flow to forced vital capacity. Forty percent (186 of 465) of this population (including students from 11 of 12 surveyed communities) reported the odor of wildfire smoke at home. We observed increased respiratory and eye symptoms with increasing frequency of wildfire smoke exposure. Associations between smoke exposure and having any of 4 respiratory symptoms were stronger in the lowest quartile of the lung function ratio (eg, fire smoke 6+ days: prevalence ratio: 3.8; 95% confidence interval (CI = 2.0-7.2), compared with the remaining quartiles (fire smoke 6+ days: prevalence ratio = 2.0; 1.2-3.2). Analysis of individual symptoms suggests that this interaction may be strongest for effects on wheezing. Small airways may serve as a marker of susceptibility to effects of wildfire smoke. Future studies should investigate the role of airway size for more common exposures and should include persons with asthma.

Occupational exposure to airborne lead in Brazilian police officers.

PubMed

Rocha, Ernesto Díaz; Sarkis, Jorge E Souza; Carvalho, Maria de Fátima H; Santos, Gerson Vechio Dos; Canesso, Claudemir

2014-07-01

Shooting with lead-containing ammunition in indoor firing ranges is a known source of lead exposure in adults. Police officers may be at risk of lead intoxication when regular training shooting exercises are yearly mandatory to law enforcement officers. Effects on health must be documented, even when low-level elemental (inorganic) lead exposure is detected. Forty police officers (nineteen cadets and twenty-one instructors) responded to a questionnaire about health, shooting habits, and potential lead exposure before a training curse. Blood samples were collected and analyzed for blood lead level (BLL) before and after a three days training curse. The mean BLL for the instructors' group was 5.5 μg/dL ± 0.6. The mean BLL for the cadets' group before the training was 3.3 μg/dL ± 0.15 and after the training the main BLL was 18.2 μg/d L± 1.5. Samples were analyzed by Inductively Coupled Plasma Mass Spectrometer (ICP-MS). All the participants in the training curse had significantly increased BLL (mean increment about 15 μg/dL) after the three days indoor shooting season. In conclusion, occupational lead exposure in indoor firing ranges is a source of lead exposure in Brazilian police officers, and appears to be a health risk, especially when heavy weapons with lead-containing ammunition are used in indoor environments during the firing training seasons. Copyright © 2013 Elsevier GmbH. All rights reserved.

Health hazard evaluation report HETA 91-124-2192, U. S. Park Police, Washington, DC

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

Echt, A.; Klein, M.; Reh, C.M.

1992-03-01

In response to a request from the U.S. Park Police (SIC-9221), Washington, D.C., a study was undertaken of possible hazardous exposures to lead (7439921) at a new indoor firing range. Air sampling revealed that for students using the range during training, the 8 hour time weighted average (TWA) exposures ranged from 4.4 micrograms/cubic meter (microg/cu m) to 116.4 microg/cu m of airborne lead, with a mean of 32.5 microg/cu m. For range officers, the TWA exposures ranged from 0.15 to 52.6 microg/cu m, mean 16.1 microg/cu m. Area samples ranged from 0.15 to 2291.1 microg/cu m. During qualification shooting, themore » 8 hour TWA exposures for students ranged from 1.0 to 103.8 microg/cu m, with a mean of 26.3 microg/cu m. For range officers, the 8 hour TWA exposures ranged from 9.7 to 39.8 microg/cu m, mean 18.0 microg/cu m. A smoke machine was used to visualize the air patterns in the firing range. It was found that contaminated air could be pulled from downrange to behind the shooting line. The authors conclude that overexposure to lead occurred during use of the firing range, due to deficiencies in the range ventilation system. The authors recommend specific measures to lessen the hazardous exposures.« less

Skin analysis following dermal exposure to kerosene in rats: the effects of postmortem exposure and fire.

PubMed

Hieda, Yoko; Tsujino, Yoshio; Xue, Yuying; Takayama, Koji; Fujihara, Junko; Kimura, Kojiro; Dekio, Satoshi

2004-02-01

To evaluate the usefulness of skin analysis for the forensic examination of cases involving postmortem dermal exposure to kerosene and/or fire, an experimental study using rats was performed. Rats received dermal exposure to kerosene before or after death, and the effect of fire was determined by burning an area of exposed skin after death. Kerosene concentrations in skin and blood were determined by gas chromatography-mass spectrometry and microscopic observation was performed for skin samples. No differences were observed in skin kerosene levels between antemortem and postmortem exposure. Kerosene concentrations in mildly burned skin where the stratum corneum (SC) was retained were approximately 84% compared to those in non-burned exposed skin, whereas concentrations in severely burned skin where the SC was almost completely burned off were 28% of non-burned skin. Even in non-exposed control skin 14% of the original kerosene concentrations could be detected, which was considered to be caused by contamination during the experimental protocol combined with kerosene's property of a high affinity for the SC. These results suggest that (1) skin analysis is useful in estimating the type of petroleum product involved in crimes or accidents even for postmortem exposure, (2) whether the SC is retained or not primarily determined the kerosene levels in burned skin, and (3) attention must be paid to evaluate the results obtained from skin samples in the light of the circumstances surrounding the case.

Evaluation of Firefighter Exposure to Wood Smoke during Training Exercises at Burn Houses.

PubMed

Fernando, Sujan; Shaw, Lorraine; Shaw, Don; Gallea, Michael; VandenEnden, Lori; House, Ron; Verma, Dave K; Britz-McKibbin, Philip; McCarry, Brian E

2016-02-02

Smoke from wood-fueled fires is one of the most common hazards encountered by firefighters worldwide. Wood smoke is complex in nature and contains numerous compounds, including methoxyphenols (MPs) and polycyclic aromatic hydrocarbons (PAHs), some of which are carcinogenic. Chronic exposure to wood smoke can lead to adverse health outcomes, including respiratory infections, impaired lung function, cardiac infarctions, and cancers. At training exercises held in burn houses at four fire departments across Ontario, air samples, skin wipes, and urine specimens from a cohort of firefighters (n = 28) were collected prior to and after exposure. Wood was the primary fuel used in these training exercises. Air samples showed that MP concentrations were on average 5-fold greater than those of PAHs. Skin wipe samples acquired from multiple body sites of firefighters indicated whole-body smoke exposure. A suite of MPs (methyl-, ethyl-, and propylsyringol) and deconjugated PAH metabolites (hydroxynaphthalene, hydroxyfluorene, hydroxyphenanthrene, and their isomers) were found to be sensitive markers of smoke exposure in urine. Creatinine-normalized levels of these markers were significantly elevated (p < 0.05) in 24 h postexposure urine despite large between-subject variations that were dependent on the specific operational roles of firefighters while using personal protective equipment. This work offers deeper insight into potential health risk from smoke exposure that is needed for translation of better mitigation policies, including improved equipment to reduce direct skin absorption and standardized hygiene practices implemented at different regional fire services.

Microdosimetric Analysis Confirms Similar Biological Effectiveness of External Exposure to Gamma-Rays and Internal Exposure to 137Cs, 134Cs, and 131I

PubMed Central

Sato, Tatsuhiko; Manabe, Kentaro; Hamada, Nobuyuki

2014-01-01

The risk of internal exposure to 137Cs, 134Cs, and 131I is of great public concern after the accident at the Fukushima-Daiichi nuclear power plant. The relative biological effectiveness (RBE, defined herein as effectiveness of internal exposure relative to the external exposure to γ-rays) is occasionally believed to be much greater than unity due to insufficient discussions on the difference of their microdosimetric profiles. We therefore performed a Monte Carlo particle transport simulation in ideally aligned cell systems to calculate the probability densities of absorbed doses in subcellular and intranuclear scales for internal exposures to electrons emitted from 137Cs, 134Cs, and 131I, as well as the external exposure to 662 keV photons. The RBE due to the inhomogeneous radioactive isotope (RI) distribution in subcellular structures and the high ionization density around the particle trajectories was then derived from the calculated microdosimetric probability density. The RBE for the bystander effect was also estimated from the probability density, considering its non-linear dose response. The RBE due to the high ionization density and that for the bystander effect were very close to 1, because the microdosimetric probability densities were nearly identical between the internal exposures and the external exposure from the 662 keV photons. On the other hand, the RBE due to the RI inhomogeneity largely depended on the intranuclear RI concentration and cell size, but their maximum possible RBE was only 1.04 even under conservative assumptions. Thus, it can be concluded from the microdosimetric viewpoint that the risk from internal exposures to 137Cs, 134Cs, and 131I should be nearly equivalent to that of external exposure to γ-rays at the same absorbed dose level, as suggested in the current recommendations of the International Commission on Radiological Protection. PMID:24919099

Blast-induced tinnitus and hyperactivity in the auditory cortex of rats.

PubMed

Luo, Hao; Pace, Edward; Zhang, Jinsheng

2017-01-06

Blast exposure can cause tinnitus and hearing impairment by damaging the auditory periphery and direct impact to the brain, which trigger neural plasticity in both auditory and non-auditory centers. However, the underlying neurophysiological mechanisms of blast-induced tinnitus are still unknown. In this study, we induced tinnitus in rats using blast exposure and investigated changes in spontaneous firing and bursting activity in the auditory cortex (AC) at one day, one month, and three months after blast exposure. Our results showed that spontaneous activity in the tinnitus-positive group began changing at one month after blast exposure, and manifested as robust hyperactivity at all frequency regions at three months after exposure. We also observed an increased bursting rate in the low-frequency region at one month after blast exposure and in all frequency regions at three months after exposure. Taken together, spontaneous firing and bursting activity in the AC played an important role in blast-induced chronic tinnitus as opposed to acute tinnitus, thus favoring a bottom-up mechanism. Copyright © 2016 IBRO. Published by Elsevier Ltd. All rights reserved.

Expansion Of Sugarcane Production In São Paulo, Brazil: Implications For Fire Occurrence And Respiratory Health

NASA Astrophysics Data System (ADS)

Uriarte, M.

2008-12-01

Recent increases in the price of oil have generated much interest in biofuel development. Despite the increasing demand, the social and environmental impacts of large scale adoption of biofuels at both regional and national scales remain understudied, especially in developing economies. Here we use municipality-level data for the state of São Paulo in Brasil to explore the effects of fires associated with sugarcane cultivation on respiratory health of elderly and children. We examined the effects of fires occurring in the same year in which respiratory cases were reported as well as chronic effects associated with long-term cultivation of sugarcane. Across the state, respiratory morbidity attributable to fires accounted for 113 elderly and 317 child cases, approximately 1.8% of total cases in each group. Although no chronic effects of fire were detected for the elderly group, an additional 650 child cases can be attributed to the long term cultivation of sugar cane increasing to 5.4% the percent of children cases that can be attributed to fire. For municipalities with greater than 50% of the land in sugarcane the percentage increased to 15% and 12 % respectively for elderly and children. An additional 209 child cases could also be attributed to past exposure to fires associated with sugarcane, suggesting that in total 38% of children respiratory cases could be attributed to current or chronic exposure to fires in these municipalities. The harmful effects of cane- associated fires on health are not only a burden for the public health system but also for household economies. This type of information should be incorporated into land use decisions and discussions of biofuel sustainability.

Toxicity of carbon monoxide hydrogen cyanide gas mixtures : exposure concentration, time to incapacitation, carboxyhemoglobin and blood cyanide parameters.

DOT National Transportation Integrated Search

1994-04-01

During aircraft interior fires, carbon monoxide (CO) and hydrogen cyanide (HCN) are produced in sufficient amounts to cause incapacitation and death. Time-to-incapacitation (ti) is a practical parameter for estimating escape time in fire environments...

Post-processing flame-retardant for polyurethane

NASA Technical Reports Server (NTRS)

Monaghan, P.; Sidman, K. R.

1980-01-01

Treatment of polyurethane form with elastomer formulation after processing makes foam fire resistant without compromising physical properties. In testing, once ignition source is removed, combustion stops. Treatment also prevents molten particle formation, generates no smoke or toxic gases in fire, and does not deteriorate under prolonged exposure to Sun.

Evaluation of post-fire strength of concrete flexural members reinforced with glass fiber reinforced polymer (GFRP) bars

NASA Astrophysics Data System (ADS)

Ellis, Devon S.

Owing to their corrosion resistance and superior strength to weight ratio, there has been, over the past two decades, increased interest in the use of fiber-reinforced polymer (FRP) reinforcing bars in reinforced concrete structural members. The mechanical behavior of FRP reinforcement differs from that of steel reinforcement. For example, FRP reinforcement exhibit a linear stress-strain behavior until the bar ruptures and the strength, stiffness and bond properties of FRP reinforcement are affected more adversely by elevated temperatures. All structures are subject to the risk of damage by fire and fires continue to be a significant cause of damage to structures. Many structures do not collapse after being exposed to fire. The safety of the structure for any future use is dependent on the ability to accurately estimate the post-fire load capacity of the structure. Assuming that the changes, due to fire exposure, in the mechanical behavior of the GFRP reinforcing bar and concrete, and the bond between the reinforcing bar and the concrete are understood, an analytical procedure for estimating the post-fire strength of GFRP reinforced concrete flexural elements can be developed. This thesis investigates the changes in: a) tensile properties and bond of GFRP bars; and b) the flexural behavior of GFRP reinforced concrete beams flexural after being exposed to elevated temperatures up to 400°C and cooled to ambient temperature. To this end, twelve tensile tests, twelve pullout bond tests and ten four-point beam tests were performed. The data from the tests were used to formulate analytical procedures for evaluating the post-fire strength of GFRP reinforced concrete beams. The procedure produced conservative results when compared with the experimental data. In general, the residual tensile strength and modulus of elasticity of GFRP bars decrease as the exposure temperature increases. The loss in properties is however, smaller than that observed by other researchers when similar bars were tested while hot. The residual bond strength was also found to decrease with increase in exposure temperature. Residual bond mechanism and flexural behavior were found to be influenced, in complex ways, by the exposure to elevated temperatures. Additionally, an apparent "yielding plateau" and an apparent increase in bar ductility was observed in the post-heat behavior of some of the tensile specimens. This points to a potential for heat treatment of FRP bars to achieve higher ductility.

Acute health effects among firefighters exposed to a polyvinyl chloride (PVC) fire

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

Markowitz, J.S.; Gutterman, E.M.; Schwartz, S.

1989-05-01

Firefighters are frequently being called on to fight fires that are chemical in nature. In the aftermath of a chemical fire in Plainfield, New Jersey on March 20-21, 1985, the authors conducted a retrospective cohort study which surveyed 80 firefighters exposed to burning polyvinyl chloride (PVC) as well as 15 nonexposed firefighter subjects. By means of an 81-item symptom checklist, exposed firefighters reported more frequent and severe symptoms at 5-6 weeks post incident. This was true for a total symptomatology score as well as 19 individual items. Some of the items with an elevated risk were consistent with exposure tomore » hydrogen chloride, the main pyrolysis product of polyvinyl chloride. Other items with an elevated risk appeared to be related to smoke inhalation while others seemed psychosocial in nature. Analyses conducted within the exposed firefighter group showed that fighting the fire the first day, being a truckman, and residence within 1 mile (1.6 km) of the firehouse were significant risk factors for high total symptom scores. These risk factors may have been associated with level or duration of exposure to the toxic substances produced during the fire.« less

Peat Biomass Smoke Particle Exposure in Rats Decreases ...

EPA Pesticide Factsheets

Wildland fires, favored by prolonged drought and rising temperatures, generate significant amounts of ambient particulate matter (PM), which has been linked to adverse health outcomes. The eastern North Carolina peat fires of Pocosin Lake in 2008 and Pains Bay in 2011 were some of the more prominent recent wildland fires and were associated with increased cardiovascular hospitalizations. The biological impacts of peat biomass emissions and the specific mechanisms driving these responses are unclear. The purpose of this study was to investigate the cardiopulmonary responses of peat biomass smoke exposure in rats. We hypothesized that PM exposure would dose-dependently alter cardiopulmonary function. Male Sprague-Dawley rats were exposed to 30 µg (Lo PM) or 300 µg (Hi PM) of peat biomass smoke PM extracts suspended in 200 µL of saline, or saline vehicle alone by oropharyngeal aspiration (OA). Immediately following OA rats were placed in a whole-body plethysmograph and ventilatory data were recorded for 12 minutes. One day following OA, rats were anesthetized with isoflurane for ultrasound assessment of cardiovascular function. Hi PM caused decreases in expiratory timing as early as 4-6 minutes after exposure relative to Lo PM (p = 0.02) and Vehicle (p= 0.06), which resolved shortly thereafter. One day after OA, ultrasounds revealed that Hi PM exposure increased end diastolic volume (EDV) by 16% (p = 0.03) over Vehicle and 13% (p = 0.06) over Lo PM. In addition,

Wildland fire management and air quality in the southern Sierra Nevada: using the Lion Fire as a case study with a multi-year perspective on PM(2.5) impacts and fire policy.

PubMed

Schweizer, Don; Cisneros, Ricardo

2014-11-01

Management of fire is an important and controversial policy issue. Active fire suppression has led to a backlog of fuels, limited the ecological benefits of fire, and reduced short-term smoke impacts likely delaying these emissions to future generations over a larger spatial extent. Smoke impacts can be expected to increase as fire size and intensity increase and the fuel backlog is consumed; whether through reintroduction of fire under desirable conditions or through stand replacing fire. Land Management Agencies would like to increase the use of naturally ignited fires to burn during favorable conditions as a way to reduce catastrophic fires. This study provides information about the levels of air quality impacts expected from these types of fires and discusses some of the policy controversies of managed fire that propagate inconsistencies between agencies and enter the public discourse. The Lion Fire, a primarily low intensity 8,370 ha fire that was extensively monitored for Particulate Matter less than 2.5 microns (PM2.5), is used to quantify impacts to air quality. PM2.5 monitoring sites are used to assess exposure, public health impacts, and subsequently quantify annual air quality during a year with a fire that is within the historic normal fire size and intensity for this area. Ground level PM2.5 impacts were found to be localized with 99% of the hourly Air Quality Index readings in the moderate or good category for the sites impacted by the fire. PM2.5 concentrations at sites nearest the fire were below annual federal air quality standards for PM2.5 with annual 98th percentile at the most impacted sites (Johnsondale, Kernville, and Camp Nelson) of 35.0, 34.0, and 28.0 μg m(-3) respectively. Smoke impacts to PM2.5 concentrations were not found to reach the populated Central Valley. The findings suggest that this type of fire can be implemented with minimal public health impacts thus allowing an opportunity for air and fire managers to alter policy to allow additional burning in an area with severe anthropogenic air pollution and where frequent widespread fire is both beneficial and inevitable. The more extensive air quality impacts documented with large high intensity fire may be averted by embracing the use of fire to prevent unwanted high intensity burns. A widespread increase in the use of fire for ecological benefit may provide the resiliency needed in Sierra Nevada forests as well as be the most beneficial to public health through the reduction of single dose exposure to smoke and limiting impacts spatially. Copyright © 2014 Elsevier Ltd. All rights reserved.

PBPK and population modelling to interpret urine cadmium concentrations of the French population

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

Béchaux, Camille, E-mail: Camille.bechaux@anses.fr; Bodin, Laurent; Clémençon, Stéphan

As cadmium accumulates mainly in kidney, urinary concentrations are considered as relevant data to assess the risk related to cadmium. The French Nutrition and Health Survey (ENNS) recorded the concentration of cadmium in the urine of the French population. However, as with all biomonitoring data, it needs to be linked to external exposure for it to be interpreted in term of sources of exposure and for risk management purposes. The objective of this work is thus to interpret the cadmium biomonitoring data of the French population in terms of dietary and cigarette smoke exposures. Dietary and smoking habits recorded inmore » the ENNS study were combined with contamination levels in food and cigarettes to assess individual exposures. A PBPK model was used in a Bayesian population model to link this external exposure with the measured urinary concentrations. In this model, the level of the past exposure was corrected thanks to a scaling function which account for a trend in the French dietary exposure. It resulted in a modelling which was able to explain the current urinary concentrations measured in the French population through current and past exposure levels. Risk related to cadmium exposure in the general French population was then assessed from external and internal critical values corresponding to kidney effects. The model was also applied to predict the possible urinary concentrations of the French population in 2030 assuming there will be no more changes in the exposures levels. This scenario leads to significantly lower concentrations and consequently lower related risk. - Highlights: • Interpretation of urine cadmium concentrations in France • PBPK and Bayesian population modelling of cadmium exposure • Assessment of the historic time-trend of the cadmium exposure in France • Risk assessment from current and future external and internal exposure.« less

Exposure to Community Violence and the Trajectory of Internalizing and Externalizing Symptoms in a Sample of Low-Income Urban Youth.

PubMed

Taylor, Jeremy J; Grant, Kathryn E; Zulauf, Courtney A; Fowler, Patrick J; Meyerson, David A; Irsheid, Sireen

2018-01-01

This study examined trajectories of psychopathology in a sample of low-income urban youth and tested exposure to community violence as a predictor of these trajectories. Self-report and parent-report survey measures of psychological problems and exposure to community violence were collected annually over 3 years from a sample of 364 fifth- to ninth-grade low-income urban youth (64% female; 95% youth of color). Linear growth models showed that youth experienced declines in both internalizing and externalizing symptoms across adolescence. Exposure to community violence was more strongly associated with externalizing symptoms than with internalizing symptoms but predicted declines in both types of symptoms. Results also indicated that youth reported more internalizing and externalizing symptoms than their parents reported for them. Exposure to community violence may explain unique trajectories of mental health problems among low-income urban youth. In addition, youth efforts to adopt a tough façade in the face of community violence could lead to higher rates of externalizing problems relative to internalizing problems, whereas desensitization processes may better explain reductions in both types of symptoms over time. Finally, youth report may be more valid than parent report in the context of urban poverty.

THE POTENTIAL APPLICATION OF FIRESAT DATA TO ASSESSMENT OF HUMAN EXPOSURES TO WILDFIRE EMISSIONS

EPA Science Inventory

FireSat is a proposed NASA mission that will obtain global coverage of the occurrence of wildfires. The specifications for FireSat are described in detail by Levine et al., (1991). Because of limitations of instruments (designed for other purposes) in existing satellites, new in...

Partial Analysis of Insta-Foam

NASA Technical Reports Server (NTRS)

Chou, L. W.

1983-01-01

Insta-Foam, used as a thermal insulator for the non-critical area of the external tank during the prelaunch phase to minimize icing, is a two-component system. Component A has polyisocyanates, blowing agents, and stabilizers; Component B has the polyols, catalysts, blowing agents, stabilizers and fire retardant. The blowing agents are Freon 11 and Freon 12, the stabilizers are silicone surfactants, the catalysts are tertiary amines, and the fire retardant is tri-(beta-chloro-isopropyl) phosphate (PCF). High performance liquid chromatography (HPLC) was quantitatively identified polyols and PFC.

Fires, A Joint Professional Bulletin for US Field & Air Defense Artillerymen. July-August 07

DTIC Science & Technology

2007-08-01

Zafaraniya area of southeast Baghdad in the Karada Security District. (Photo by SSgt Bronco Suzuki, USAF) The Fires staff wishes to thank RCW...not “cut and run.” External Support. The UN was suc- cessful in stabilizing El Salvador after an exceptionally bloody civil war, in large part by...involving neighboring states that were desperate to keep the conflict from spilling over El Salvador’s borders onto their soil. A family in Northern

Biomonitoring of chemical exposure among New York City firefighters responding to the World Trade Center fire and collapse.

PubMed

Edelman, Philip; Osterloh, John; Pirkle, James; Caudill, Sam P; Grainger, James; Jones, Robert; Blount, Ben; Calafat, Antonia; Turner, Wayman; Feldman, Debra; Baron, Sherry; Bernard, Bruce; Lushniak, Boris D; Kelly, Kerry; Prezant, David

2003-12-01

The collapse of the World Trade Center (WTC) on 11 September 2001 exposed New York City firefighters to smoke and dust of unprecedented magnitude and duration. The chemicals and the concentrations produced from any fire are difficult to predict, but estimates of internal dose exposures can be assessed by the biological monitoring of blood and urine. We analyzed blood and urine specimens obtained from 321 firefighters responding to the WTC fires and collapse for 110 potentially fire-related chemicals. Controls consisted of 47 firefighters not present at the WTC. Sampling occurred 3 weeks after 11 September, while fires were still burning. When reference or background ranges were available, most chemical concentrations were found to be generally low and not outside these ranges. Compared with controls, the exposed firefighters showed significant differences in adjusted geometric means for six of the chemicals and significantly greater detection rates for an additional three. Arrival time was a significant predictor variable for four chemicals. Special Operations Command firefighters (n = 95), compared with other responding WTC firefighters (n = 226), had differences in concentrations or detection rate for 14 of the chemicals. Values for the Special Operations Command firefighters were also significantly different from the control group values for these same chemicals and for two additional chemicals. Generally, the chemical concentrations in the other firefighter group were not different from those of controls. Biomonitoring was used to characterize firefighter exposure at the WTC disaster. Although some of the chemicals analyzed showed statistically significant differences, these differences were generally small.

A Five- Year CMAQ Model Performance for Wildfires and ...

EPA Pesticide Factsheets

Biomass burning has been identified as an important contributor to the degradation of air quality because of its impact on ozone and particulate matter. Two components of the biomass burning inventory, wildfires and prescribed fires are routinely estimated in the national emissions inventory. However, there is a large amount of uncertainty in the development of these emission inventory sectors. We have completed a 5 year set of CMAQ model simulations (2008-2012) in which we have simulated regional air quality with and without the wildfire and prescribed fire inventory. We will examine CMAQ model performance over regions with significant PM2.5 and Ozone contribution from prescribed fires and wildfires. The National Exposure Research Laboratory (NERL) Computational Exposure Division (CED) develops and evaluates data, decision-support tools, and models to be applied to media-specific or receptor-specific problem areas. CED uses modeling-based approaches to characterize exposures, evaluate fate and transport, and support environmental diagnostics/forensics with input from multiple data sources. It also develops media- and receptor-specific models, process models, and decision support tools for use both within and outside of EPA.

10 CFR Appendix C to Part 835 - Derived Air Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of...

Code of Federal Regulations, 2010 CFR

2010-01-01

... Exposure During Immersion in a Cloud of Airborne Radioactive Material C Appendix C to Part 835 Energy... Concentration (DAC) for Workers From External Exposure During Immersion in a Cloud of Airborne Radioactive... identifying the need for posting of airborne radioactivity areas in accordance with § 835.603(d). b. The air...

Computational Approach to Identify Different Injuries by Firearms.

PubMed

Costa, Sarah Teixeira; Freire, Alexandre Rodrigues; Matoso, Rodrigo Ivo; Daruge Júnior, Eduardo; Rossi, Ana Cláudia; Prado, Felippe Bevilacqua

2017-03-01

Complications arise in the analysis of gunshot wounds to the maxillofacial region, when neither the projectile nor the gun is found at the crime scene. We simulated 5- and 15-cm firing distances at a human mandible to investigate the external morphology of entrance wounds based on fire range. The ammunition models, .40-caliber S&W, .380-caliber, and 9 × 19-mm Luger, were constructed with free-form NURBS surfaces. In a dynamic simulation, projectiles were fired against mandibular body 3D model at 5 and 15 cm. All entrance wounds presented oval aspect. Maximum diameter and von Mises stress values were 16.5 mm and 50.8 MPa, both for .40-caliber S&W fired at 5 cm. The maximum energy loss was 138.4 J for .40 S&W fired at 15 cm. In conclusion, the mandible was most affected by .40-caliber S&W and morphological differences were observable in holes caused by different incoming projectile calibers fired at different distances. © 2017 American Academy of Forensic Sciences.

Fire behavior of halogen-free flame retardant electrical cables with the cone calorimeter.

PubMed

Meinier, Romain; Sonnier, Rodolphe; Zavaleta, Pascal; Suard, Sylvain; Ferry, Laurent

2018-01-15

Fires involving electrical cables are one of the main hazards in Nuclear Power Plants (NPPs). Cables are complex assemblies including several polymeric parts (insulation, bedding, sheath) constituting fuel sources. This study provides an in-depth characterization of the fire behavior of two halogen-free flame retardant cables used in NPPs using the cone calorimeter. The influence of two key parameters, namely the external heat flux and the spacing between cables, on the cable fire characteristics is especially investigated. The prominent role of the outer sheath material on the ignition and the burning at early times was highlighted. A parameter of utmost importance called transition heat flux, was identified and depends on the composition and the structure of the cable. Below this heat flux, the decomposition is limited and concerns only the sheath. Above it, fire hazard is greatly enhanced because most often non-flame retarded insulation part contributes to heat release. The influence of spacing appears complex, and depends on the considered fire property. Copyright © 2017 Elsevier B.V. All rights reserved.

Evaluation of a boron-nitrogen, phosphate-free fire-retardant treatment. Part II, Testing of small clear specimens per ASTM Standard D 5664-95, Methods A and B

Treesearch

Jerrold E. Winandy; Douglas Herdman

2003-01-01

The objective of this work was to evaluate the effects of a new boron-nitrogen, phosphate-free fire-retardant (FR) formulation on several mechanical properties of FR-treated wood and to assess the potential of this treatment for in-service thermal-induced strength loss resulting from exposure to high temperature. Fire-retardant-treated and untreated small clear...

Evaluating the Efficiency of Air Shower in Removing Lead from Army Combat Uniform Swatches Loaded with Gunshot Residue

DTIC Science & Technology

2016-03-25

well-known toxicant and the exposure on indoor firing ranges presents a health risk to both range employees and shooters. Contaminated clothing... firing ranges have employed a new control – air shower (AS), although its effectiveness in this particular application has not been examined. The... firing lead- containing ammunition inside a sealed chamber and allowing the gunshot residue to settle on swatches placed inside the chamber. The

Occupational Lead Exposure from Indoor Firing Ranges in Korea

PubMed Central

Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik

2016-01-01

Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea’s Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0–64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations. PMID:27051231

Occupational Lead Exposure from Indoor Firing Ranges in Korea.

PubMed

Park, Won-Ju; Lee, Suk-Ho; Lee, Se-Ho; Yoon, Hye-Sik; Moon, Jai-Dong

2016-04-01

Military personnel often use ammunitions that contain lead. The present study aimed to identify the risks for lead exposure and lead poisoning among workers at indoor firing ranges. A special health examination, including blood lead level (BLL) testing, was performed for all 120 workers at the indoor firing ranges of the Republic of Korea's Air Force, Navy, and Armed Forces Athletic Corps. The overall mean BLL was 11.3 ± 9.4 µg/dL (range: 2.0-64.0 µg/dL). The arithmetic mean of the BLL for professional shooters belong to Armed Forces Athletic Corps was 14.0 ± 8.3 µg/dL, while those of shooting range managers and shooting range supervisors were 13.8 ± 11.1 µg/dL and 6.4 ± 3.1 µg/dL, respectively. One individual had a BLL of 64 µg/dL, and ultimately completed chelation treatment (with CaNa2-ethylenediaminetetraacetic acid) without any adverse effects. These findings indicate that indoor firing range workers are exposed to elevated levels of lead. Therefore, when constructing an indoor firing range, a specialist should be engaged to design and assess the ventilation system; and safety guidelines regarding ammunition and waste handling must be mandatory. Moreover, workplace environmental monitoring should be implemented for indoor firing ranges, and the workers should undergo regularly scheduled special health examinations.

Tremor-related activity of neurons in the 'motor' thalamus: changes in firing rate and pattern in the MPTP vervet model of parkinsonism.

PubMed

Guehl, D; Pessiglione, M; François, C; Yelnik, J; Hirsch, E C; Féger, J; Tremblay, L

2003-06-01

The pathophysiology of parkinsonian tremor remains a matter of debate with two opposing hypotheses proposing a peripheral and a central origin, respectively. A central origin of tremor could arise either from a rhythmic activity of the internal segment of the globus pallidus (GPi) or from a structure such as the thalamus, outside the basal ganglia. In this study, single-unit recordings were performed in three 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine-treated monkeys within the GPi and within three territories of the motor thalamus (delimited by their afferent inputs from the GPi, the substantia nigra and the cerebellum, respectively). For each recorded neuron, we compared the variations in firing rate and pattern in tremor and no tremor periods. Tremor either occurred spontaneously or was induced by external stimulation. When the animals entered into a tremor period we observed: (i) an increase in the mean firing rate in about half of the recorded neurons of the motor thalamus; and (ii), a change from an irregular to a rhythmic discharge within the range of tremor frequency (5-7 Hz) in about 10% of the recorded neurons of the motor thalamus (pallidal and cerebellar territories) and the GPi. Most of the thalamic neurons that exhibited a rhythmic discharge during tremor were found to be sensitive to external stimulation. Because the changes in firing rate occurred predominantly in the motor thalamus and not in the GPi, and because a fast rhythmic discharge of 10-15 Hz was frequently observed in the GPi and not in the motor thalamus, we conclude that thalamic activity is not a simple reproduction of basal ganglia output. Moreover, we suggest that thalamic processing of basal ganglia outputs could participate in the genesis of tremor, and that this thalamic processing could be influenced by sensory inputs and/or changes in attentional level elicited by external stimulation.

Pilot task-based assessment of noise levels among firefighters.

PubMed

Neitzel, Rl; Hong, O; Quinlan, P; Hulea, R

2013-11-01

Over one million American firefighters are routinely exposed to various occupational hazards agents. While efforts have been made to identify and reduce some causes of injuries and illnesses among firefighters, relatively little has been done to evaluate and understand occupational noise exposures in this group. The purpose of this pilot study was to apply a task-based noise exposure assessment methodology to firefighting operations to evaluate potential noise exposure sources, and to use collected task-based noise levels to create noise exposure estimates for evaluation of risk of noise-induced hearing loss by comparison to the 8-hr and 24-hr recommended exposure limits (RELs) for noise of 85 and 80.3 dBA, respectively. Task-based noise exposures (n=100 measurements) were measured in three different fire departments (a rural department in Southeast Michigan and suburban and urban departments in Northern California). These levels were then combined with time-at-task information collected from firefighters to estimate 8-hr noise exposures for the rural and suburban fire departments (n=6 estimates for each department). Data from 24-hr dosimetry measurements and crude self-reported activity categories from the urban fire department (n=4 measurements) were used to create 24-hr exposure estimates to evaluate the bias associated with the task-based estimates. Task-based noise levels were found to range from 82-109 dBA, with the highest levels resulting from use of saws and pneumatic chisels. Some short (e.g., 30 min) sequences of common tasks were found to result in nearly an entire allowable daily exposure. The majority of estimated 8-hr and 24-hr exposures exceeded the relevant recommended exposure limit. Predicted 24-hr exposures showed substantial imprecision in some cases, suggesting the need for increased task specificity. The results indicate potential for overexposure to noise from a variety of firefighting tasks and equipment, and suggest a need for further exposure characterization and additional hearing loss prevention efforts. Firefighters may be at risk of noise-induced hearing loss, which can affect their fitness for duty and ability to respond effectively to emergencies. The results of this study suggest that additional efforts at hearing loss prevention among firefighters are warranted.

Effect of inhibitory firing pattern on coherence resonance in random neural networks

NASA Astrophysics Data System (ADS)

Yu, Haitao; Zhang, Lianghao; Guo, Xinmeng; Wang, Jiang; Cao, Yibin; Liu, Jing

2018-01-01

The effect of inhibitory firing patterns on coherence resonance (CR) in random neuronal network is systematically studied. Spiking and bursting are two main types of firing pattern considered in this work. Numerical results show that, irrespective of the inhibitory firing patterns, the regularity of network is maximized by an optimal intensity of external noise, indicating the occurrence of coherence resonance. Moreover, the firing pattern of inhibitory neuron indeed has a significant influence on coherence resonance, but the efficacy is determined by network property. In the network with strong coupling strength but weak inhibition, bursting neurons largely increase the amplitude of resonance, while they can decrease the noise intensity that induced coherence resonance within the neural system of strong inhibition. Different temporal windows of inhibition induced by different inhibitory neurons may account for the above observations. The network structure also plays a constructive role in the coherence resonance. There exists an optimal network topology to maximize the regularity of the neural systems.

A Model of Generating Visual Place Cells Based on Environment Perception and Similar Measure.

PubMed

Zhou, Yang; Wu, Dewei

2016-01-01

It is an important content to generate visual place cells (VPCs) in the field of bioinspired navigation. By analyzing the firing characteristic of biological place cells and the existing methods for generating VPCs, a model of generating visual place cells based on environment perception and similar measure is abstracted in this paper. VPCs' generation process is divided into three phases, including environment perception, similar measure, and recruiting of a new place cell. According to this process, a specific method for generating VPCs is presented. External reference landmarks are obtained based on local invariant characteristics of image and a similar measure function is designed based on Euclidean distance and Gaussian function. Simulation validates the proposed method is available. The firing characteristic of the generated VPCs is similar to that of biological place cells, and VPCs' firing fields can be adjusted flexibly by changing the adjustment factor of firing field (AFFF) and firing rate's threshold (FRT).

A Model of Generating Visual Place Cells Based on Environment Perception and Similar Measure

PubMed Central

2016-01-01

It is an important content to generate visual place cells (VPCs) in the field of bioinspired navigation. By analyzing the firing characteristic of biological place cells and the existing methods for generating VPCs, a model of generating visual place cells based on environment perception and similar measure is abstracted in this paper. VPCs' generation process is divided into three phases, including environment perception, similar measure, and recruiting of a new place cell. According to this process, a specific method for generating VPCs is presented. External reference landmarks are obtained based on local invariant characteristics of image and a similar measure function is designed based on Euclidean distance and Gaussian function. Simulation validates the proposed method is available. The firing characteristic of the generated VPCs is similar to that of biological place cells, and VPCs' firing fields can be adjusted flexibly by changing the adjustment factor of firing field (AFFF) and firing rate's threshold (FRT). PMID:27597859

Federal Guidance Report No. 15: External Exposure to Radionuclides in Air, Water and Soil

EPA Pesticide Factsheets

FGR 15 updates the 1993 Federal Guidance Report No. 12 (FGR 12), External Exposure to Radionuclides in Air, Water, and Soil. FGR 15 incorporates advances in radiation protection science regarding how organ/tissue doses change with age and sex.

Household air pollution from wood burning in two reconstructed houses from the Danish Viking Age.

PubMed

Christensen, J M; Ryhl-Svendsen, M

2015-06-01

During 13 winter weeks, an experimental archeology project was undertaken in two Danish reconstructed Viking Age houses with indoor open fireplaces. Volunteers inhabited the houses under living conditions similar to those of the Viking Age, including cooking and heating by wood fire. Carbon monoxide (CO) and particulate matter (PM2.5 ) were measured at varying distances to the fireplace. Near the fireplaces CO (mean) was 16 ppm. PM2.5 (mean) was 3.40 mg/m(3) , however, measured in one house only. The CO:PM mass ratio was found to increase from 6.4 to 22 when increasing the distance to the fire. Two persons carried CO sensors. Average personal exposure was 6.9 ppm, and from this, a personal PM2.5 exposure of 0.41 mg/m(3) was estimated. The levels found here were higher than reported from modern studies conducted in dwellings using biomass for cooking and heating. While this may be due to the Viking house design, the volunteer's lack of training in attending a fire maybe also played a role. Even so, when comparing to today's issues arising from the use of open fires, it must be assumed that also during the Viking Age, the exposure to woodsmoke was a contributing factor to health problems. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Ethanol-Sensitive Pacemaker Neurons in the Mouse External Globus Pallidus

PubMed Central

Abrahao, Karina P; Chancey, Jessica H; Chan, C Savio; Lovinger, David M

2017-01-01

Although ethanol is one of the most widely used drugs, we still lack a full understanding of which neuronal subtypes are affected by this drug. Pacemaker neurons exert powerful control over brain circuit function, but little is known about ethanol effects on these types of neurons. Neurons in the external globus pallidus (GPe) generate pacemaker activity that controls basal ganglia, circuitry associated with habitual and compulsive drug use. We performed patch-clamp recordings from GPe neurons and found that bath application of ethanol dose-dependently decreased the firing rate of low-frequency GPe neurons, but did not alter the firing of high-frequency neurons. GABA or glutamate receptor antagonists did not block the ethanol effect. The GPe is comprised of a heterogeneous population of neurons. We used Lhx6-EGFP and Npas1-tdTm mice strains to identify low-frequency neurons. Lhx6 and Npas1 neurons exhibited decreased firing with ethanol, but only Npas1 neurons were sensitive to 10 mM ethanol. Large-conductance voltage and Ca2+-activated K+ (BK) channel have a key role in the ethanol effect on GPe neurons, as the application of BK channel inhibitors blocked the ethanol-induced firing decrease. Ethanol also increased BK channel open probability measured in single-channel recordings from Npas1-tdTm neurons. In addition, in vivo electrophysiological recordings from GPe showed that ethanol decreased the firing of a large subset of low-frequency neurons. These findings indicate how selectivity of ethanol effects on pacemaker neurons can occur, and enhance our understanding of the mechanisms contributing to acute ethanol effects on the basal ganglia. PMID:27827370

Assessment of human exposure to polychlorinated dibenzofurans and dioxins.

PubMed Central

Rappe, C; Nygren, M; Marklund, S; Keller, L O; Bergqvist, P A; Hansson, M

1985-01-01

Fires, explosions and other accidents in polychlorinated biphenyl (PCB)-filled equipment can result in possible exposure of firemen, cleaning personnel and regular workers. Inhalation, dermal exposure and ingestion are the possible routes of exposure. An indirect assessment of the exposure can be made by analyses of wipes, air and water samples and clothes. A direct assessment of exposure can be made by analyses of blood samples, adipose and other tissue samples, feces and bile. PMID:4029099

Effect of fire-induced damage on the uniaxial strength characteristics of solid timber: A numerical study

NASA Astrophysics Data System (ADS)

Hopkin, D. J.; El-Rimawi, J.; Lennon, T.; Silberschmidt, V. V.

2011-07-01

The advent of the structural Eurocodes has allowed civil engineers to be more creative in the design of structures exposed to fire. Rather than rely upon regulatory guidance and prescriptive methods engineers are now able to use such codes to design buildings on the basis of credible design fires rather than accepted unrealistic standard-fire time-temperature curves. Through this process safer and more efficient structural designs are achievable. The key development in enabling performance-based fire design is the emergence of validated numerical models capable of predicting the mechanical response of a whole building or sub-assemblies at elevated temperature. In such a way, efficiency savings have been achieved in the design of steel, concrete and composite structures. However, at present, due to a combination of limited fundamental research and restrictions in the UK National Annex to the timber Eurocode, the design of fire-exposed timber structures using numerical modelling techniques is not generally undertaken. The 'fire design' of timber structures is covered in Eurocode 5 part 1.2 (EN 1995-1-2). In this code there is an advanced calculation annex (Annex B) intended to facilitate the implementation of numerical models in the design of fire-exposed timber structures. The properties contained in the code can, at present, only be applied to standard-fire exposure conditions. This is due to existing limitations related to the available thermal properties which are only valid for standard fire exposure. In an attempt to overcome this barrier the authors have proposed a 'modified conductivity model' (MCM) for determining the temperature of timber structural elements during the heating phase of non-standard fires. This is briefly outlined in this paper. In addition, in a further study, the MCM has been implemented in a coupled thermo-mechanical analysis of uniaxially loaded timber elements exposed to non-standard fires. The finite element package DIANA was adopted with plane-strain elements assuming two-dimensional heat flow. The resulting predictions of failure time for given levels of load are discussed and compared with the simplified 'effective cross section' method presented in EN 1995-1-2.

Complexity of VTA DA neural activities in response to PFC transection in nicotine treated rats.

PubMed

Chen, Ting Y; Zhang, Die; Dragomir, Andrei; Akay, Yasemin M; Akay, Metin

2011-02-27

The dopaminergic (DA) neurons in the ventral tegmental area (VTA) are widely implicated in the addiction and natural reward circuitry of the brain. These neurons project to several areas of the brain, including prefrontal cortex (PFC), nucleus accubens (NAc) and amygdala. The functional coupling between PFC and VTA has been demonstrated, but little is known about how PFC mediates nicotinic modulation in VTA DA neurons. The objectives of this study were to investigate the effect of acute nicotine exposure on the VTA DA neuronal firing and to understand how the disruption of communication from PFC affects the firing patterns of VTA DA neurons. Extracellular single-unit recordings were performed on Sprague-Dawley rats and nicotine was administered after stable recording was established as baseline. In order to test how input from PFC affects the VTA DA neuronal firing, bilateral transections were made immediate caudal to PFC to mechanically delete the interaction between VTA and PFC. The complexity of the recorded neural firing was subsequently assessed using a method based on the Lempel-Ziv estimator. The results were compared with those obtained when computing the entropy of neural firing. Exposure to nicotine triggered a significant increase in VTA DA neurons firing complexity when communication between PFC and VTA was present, while transection obliterated the effect of nicotine. Similar results were obtained when entropy values were estimated. Our findings suggest that PFC plays a vital role in mediating VTA activity. We speculate that increased firing complexity with acute nicotine administration in PFC intact subjects is due to the close functional coupling between PFC and VTA. This hypothesis is supported by the fact that deletion of PFC results in minor alterations of VTA DA neural firing when nicotine is acutely administered.

Fire occurrence and tussock size modulate facilitation by Ampelodesmos mauritanicus

NASA Astrophysics Data System (ADS)

Incerti, Guido; Giordano, Daniele; Stinca, Adriano; Senatore, Mauro; Termolino, Pasquale; Mazzoleni, Stefano; Bonanomi, Giuliano

2013-05-01

Facilitation has been reported for a wide range of plant communities, with evidence of interactions between protégé and nurse plants shifting during their ontogenetic cycles. This study showed that large Ampelodesmos mauritanicus tussocks can act as nurse for different species, but only after fire occurrence. Large tussocks are typically composed by an external belt of living tillers surrounding dead standing tillers in the inner area, thus being arranged as a “ring” shape. A low plant diversity in unburned sites, dominated by intact Ampelodesmos tussocks, was related to the intense aboveground competition due to space physical limitation by standing tillers, as well as to the reduction of light availability at ground level. In contrast, after burning, tussocks resprouted only in their external belts, leaving empty inner areas. During post-fire recovery, several species (e.g. Plantago spp., Trifolium spp., Carlina spp.) recolonize the bare soil among different tussocks. On the other hand, a moss (Funaria hygrometrica) and several herbaceous and woody plants (e.g. Spartium junceum, Calicotome villosa, Quercus pubescens subsp. pubescens) were selectively distributed within the ash-full central areas of burned Ampelodesmos tussocks. In summary, the study reported evidence of changing prevalence in the interplay of competition and facilitation effects between small and large Ampelodesmos tussocks, respectively. These results suggest a broad significance of the interactions between fire occurrence and ontogenetic phases of the dominant species in affecting the restoration dynamics of natural plant communities.

Identifying vulnerable populations to death and injuries from residential fires.

PubMed

Gilbert, Stanley W; Butry, David T

2017-08-03

This study proposes and evaluates the theory that people who are susceptible to injury in residential fires are not susceptible to death in residential fires and vice versa. It is proposed that the population vulnerable to death in residential fires can be proxied by 'frailty', which is measured as age-gender adjusted fatality rates due to natural causes. This study uses an ecological approach and controls for exposure to estimate the vulnerability of different population groups to death and injury in residential fires. It allows fatalities and injuries to be estimated by different models. Frailty explains fire-related death in adults while not explaining injuries, which is consistent with the idea that deaths and injuries affect disjoint populations. Deaths and injuries in fire are drawn from different populations. People who are susceptible to dying in fires are unlikely to be injured in fires, and the people who are susceptible to injury are unlikely to die in fires. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Peat Biomass Smoke Particle Exposure in Rats Decreases Expiratory Time and Increases Left Heart End Diastolic Volume

EPA Science Inventory

Wildland fires, favored by prolonged drought and rising temperatures, generate significant amounts of ambient particulate matter (PM), which has been linked to adverse health outcomes. The eastern North Carolina peat fires of Pocosin Lake in 2008 and Pains Bay in 2011 were some o...

Development and application of a geospatial wildfire exposure and risk calculation tool

Treesearch

Matthew P. Thompson; Jessica R. Haas; Julie W. Gilbertson-Day; Joe H. Scott; Paul Langowski; Elise Bowne; David E. Calkin

2015-01-01

Applying wildfire risk assessment models can inform investments in loss mitigation and landscape restoration, and can be used to monitor spatiotemporal trends in risk. Assessing wildfire risk entails the integration of fire modeling outputs, maps of highly valued resources and assets (HVRAs), characterization of fire effects, and articulation of relative importance...

A loose bolt delays loading of Endeavour's external tank

NASA Technical Reports Server (NTRS)

2000-01-01

This view shows the pipe (center top) leading toward Endeavour from the side of the White Room at Launch Pad 39B. A loose bracket observed hanging down from the pipe delayed loading of Endeavour's external tank by several hours to allow technicians to remove it. A 'U' bolt connects the bracket to a fire suppression water line attached to the exterior of the White Room. The loose bolt could have possibly created a debris hazard.

Differences in risk and protective factors for workplace aggression between male and female clinical medical practitioners in Australia.

PubMed

Hills, Danny J

2017-07-01

Objectives The aim of the present study was to investigate differences in prevalence, as well as risk and protective factors, for exposure to workplace aggression between male and female clinicians in Australian medical practice settings. Methods In a cross-sectional, self-report study in the third wave of the Medicine in Australia: Balancing Employment and Life survey (2010-11), 16327 medical practitioners were sampled, with 9449 (57.9%) respondents working in clinical practice. Using backward stepwise elimination, parsimonious logistic regression models were developed for exposure to aggression from external (patients, patients' relatives or carers and others) and internal (co-workers) sources in the previous 12 months. Results Overall, greater proportions of female than male clinicians experienced aggression from external (P<0.001) and internal (P<0.01) sources in the previous 12 months. However, when stratified by doctor type, greater proportions of male than female general practitioners (GPs) and GP registrars experienced external aggression (P<0.05), whereas greater proportions of female than male specialists experienced external (P<0.01) and internal (P<0.01) aggression. In logistic regression models, differences were identified in relation to age for males and experience working in medicine for females with external and internal aggression; working in New South Wales (vs Victoria) and internal aggression for females; a poor medical support network and external aggression, and perceived unrealistic patient expectations with internal aggression for males; warning signs in reception and waiting areas with external aggression for males; and optimised patient waiting conditions with external and internal aggression for females. Conclusions Differences in risk and protective factors for exposure to workplace aggression between male and female clinicians, including in relation to state and rural location, need to be considered in the development and implementation of efforts to prevent and minimise workplace aggression in medical practice settings. What is known about the topic? Workplace aggression is prevalent in clinical medical settings, but there are conflicting reports about sex-based differences in the extent of exposure, and little evidence on differences in risk and protective factors for exposure to workplace aggression. What does this paper add? Differences in workplace aggression exposure rates between male and female clinicians are highlighted, including when stratified by doctor type. New evidence is reported on differences and similarities in key personal, professional and work-related factors associated with exposure to external and internal aggression. What are the implications for practitioners? In developing strategies for the prevention and minimisation of workplace aggression, consideration must be given to differences between male and female clinicians, including with regard to personality, age and professional experience, as well as work locations, conditions and settings, as risk or protective factors for exposure to aggression in medical work.

Lung cancer mortality among workers at a nuclear materials fabrication plant.

PubMed

Richardson, David B; Wing, Steve

2006-02-01

The Oak Ridge, Tennessee Y-12 plant has operated as a nuclear materials fabrication plant since the 1940s. Given the work environment, and prior findings that lung cancer mortality was elevated among white male Y-12 workers relative to US white males, we investigated whether lung cancer mortality was associated with occupational radiation exposures. A cohort of 3,864 workers hired between 1947 and 1974 who had been monitored for internal radiation exposure was identified. Vital status was ascertained through 1990. Over the study period 111 lung cancer deaths were observed. Cumulative external radiation dose under a 5-year lag assumption was positively associated with lung cancer mortality (0.54% increase in lung cancer mortality per 10 mSv, se=0.16, likelihood ratio test (LRT)=5.84, 1 degree of freedom [df]); cumulative internal radiation dose exhibited a highly-imprecise negative association with lung cancer mortality. The positive association between external radiation dose and lung cancer mortality was primarily due to exposure occurring in the period 5-14 years after exposure (0.97% increase in lung cancer mortality rate per 10 mSv, se=0.28, LRT=6.35, 1 df). The association between external radiation dose and lung cancer mortality was negative for exposures occurring at ages<35 years and positive for exposures occurring at ages 35-50 and 50+years. There is evidence of a positive association between cumulative external radiation dose and lung cancer mortality in this population. However, a causal interpretation of this association is constrained by the uncertainties in external and internal radiation dose estimates, the lack of information about exposures to other lung carcinogens, and the limited statistical power of the study. Copyright (c) 2005 Wiley-Liss, Inc.

Inner Mitochondrial Membrane Disruption Links Apoptotic and Agonist-Initiated Phosphatidylserine Externalization in Platelets.

PubMed

Choo, Hyo-Jung; Kholmukhamedov, Andaleb; Zhou, ChengZing; Jobe, Shawn

2017-08-01

Phosphatidylserine exposure mediates platelet procoagulant function and regulates platelet life span. Apoptotic, necrotic, and integrin-mediated mechanisms have been implicated as intracellular determinants of platelet phosphatidylserine exposure. Here, we investigate (1) the role of mitochondrial events in platelet phosphatidylserine exposure initiated by these distinct stimuli and (2) the cellular interactions of the procoagulant platelet in vitro and in vivo. Key mitochondrial events were examined, including cytochrome c release and inner mitochondrial membrane (IMM) disruption. In both ABT-737 (apoptotic) and agonist (necrotic)-treated platelets, phosphatidylserine externalization was temporally correlated with IMM disruption. Agonist stimulation resulted in rapid cyclophilin D-dependent IMM disruption that coincided with phosphatidylserine exposure. ABT-737 treatment caused rapid cytochrome c release, eventually followed by caspase-dependent IMM disruption that again closely coincided with phosphatidylserine exposure. A nonmitochondrial and integrin-mediated mechanism has been implicated in the formation of a novel phosphatidylserine-externalizing platelet subpopulation. Using image cytometry, this subpopulation is demonstrated to be the result of the interaction of an aggregatory platelet and a procoagulant platelet rather than indicative of a novel intracellular mechanism regulating platelet phosphatidylserine externalization. Using electron microscopy, similar interactions between aggregatory and procoagulant platelets are demonstrated in vitro and in vivo within a mesenteric vein hemostatic thrombus. Platelet phosphatidylserine externalization is closely associated with the mitochondrial event of IMM disruption identifying a common pathway in phosphatidylserine-externalizing platelets. The limited interaction of procoagulant platelets and integrin-active aggregatory platelets identifies a potential mechanism for procoagulant platelet retention within the hemostatic thrombus. © 2017 American Heart Association, Inc.

Mechanical Behavior of Recycled Aggregate Concrete-Filled Steel Tubular Columns before and after Fire.

PubMed

Liu, Wenchao; Cao, Wanlin; Zhang, Jianwei; Wang, Ruwei; Ren, Lele

2017-03-09

Recycled aggregate concrete (RAC) is an environmentally friendly building material. This paper investigates the mechanical behavior of recycled aggregate concrete filled steel tube (RACFST) columns exposed to fire. Two groups of 12 columns were designed and tested, under axial compression, before and after fire, to evaluate the degradation of bearing capacity due to fire exposure. Six specimens were subjected to axial compression tests at room temperature and the other six specimens were subjected to axial compression tests after a fire exposure. The main parameters of the specimens include the wall thickness of the steel tube (steel content) and the type of concrete materials. Several parameters as obtained from the experimental results were compared and analyzed, including the load-bearing capacity, deformation capacity, and failure characteristics of the specimens. Meanwhile, rate of loss of bearing capacity of specimens exposed to fire were calculated based on the standards EC4 and CECS28:90. The results show that concrete material has a large influence on the rate of loss of bearing capacity in the case of a relatively lower steel ratio. While steel content has little effect on the rate of loss of bearing capacity of concrete-filled steel tube (CFST) columns after fire, it has a relatively large influence on the loss rate of bearing capacity of the RACFST columns. The loss of bearing capacity of the specimens from the experiment is more serious than that from the calculation. As the calculated values are less conservative, particular attention should be given to the application of recycled aggregate concrete in actual structures.

Mechanical Behavior of Recycled Aggregate Concrete-Filled Steel Tubular Columns before and after Fire

PubMed Central

Liu, Wenchao; Cao, Wanlin; Zhang, Jianwei; Wang, Ruwei; Ren, Lele

2017-01-01

Recycled aggregate concrete (RAC) is an environmentally friendly building material. This paper investigates the mechanical behavior of recycled aggregate concrete filled steel tube (RACFST) columns exposed to fire. Two groups of 12 columns were designed and tested, under axial compression, before and after fire, to evaluate the degradation of bearing capacity due to fire exposure. Six specimens were subjected to axial compression tests at room temperature and the other six specimens were subjected to axial compression tests after a fire exposure. The main parameters of the specimens include the wall thickness of the steel tube (steel content) and the type of concrete materials. Several parameters as obtained from the experimental results were compared and analyzed, including the load-bearing capacity, deformation capacity, and failure characteristics of the specimens. Meanwhile, rate of loss of bearing capacity of specimens exposed to fire were calculated based on the standards EC4 and CECS28:90. The results show that concrete material has a large influence on the rate of loss of bearing capacity in the case of a relatively lower steel ratio. While steel content has little effect on the rate of loss of bearing capacity of concrete-filled steel tube (CFST) columns after fire, it has a relatively large influence on the loss rate of bearing capacity of the RACFST columns. The loss of bearing capacity of the specimens from the experiment is more serious than that from the calculation. As the calculated values are less conservative, particular attention should be given to the application of recycled aggregate concrete in actual structures. PMID:28772634

Effect Of Low External Flow On Flame Spreading Over ETFE Insulated Wire Under Microgravity

NASA Technical Reports Server (NTRS)

Nishizawa, Katsuhiro; Fujita, Osamu; Ito, Kenichi; Kikuchi, Masao; Olson, Sandra L.; Kashiwagi, Takashi

2003-01-01

Fire safety is one of the most important issues for manned space missions. A likely cause of fires in spacecraft is wire insulation combustion in electrical system. Regarding the wire insulation combustion it important to know the effect of low external flow on the combustion because of the presence of ventilation flow in spacecraft. Although, there are many researches on flame spreading over solid material at low external flows under microgravity, research dealing with wire insulation is very limited. An example of wire insulation combustion in microgravity is the Space Shuttle experiments carried out by Greenberg et al. However, the number of experiments was very limited. Therefore, the effect of low flow velocity is still not clear. The authors have reported results on flame spreading over ETFE (ethylene - tetrafluoroetylene) insulated wire in a quiescent atmosphere in microgravity by 10 seconds drop tower. The authors also performed experiments of polyethylene insulated nichrom wire combustion in low flow velocity under microgravity. The results suggested that flame spread rate had maximum value in low flow velocity condition. Another interesting issue is the effect of dilution gas, especially CO2, which is used for fire extinguisher in ISS. There are some researches working on dilution gas effect on flame spreading over solid material in quiescent atmosphere in microgravity. However the research with low external flow is limited and, of course, the research discussing a relation of the appearance of maximum wire flammability in low flow velocity region with different dilution gas cannot be found yet. The present paper, therefore, investigates the effect of opposed flow with different dilution gas on flame spreading over ETFE insulated wire and change in the presence of the maximum flammability depending on the dilution gas type is discussed within the limit of microgravity time given by ground-based facility.

Does crash risk increase when emergency vehicles are driving with lights and sirens?

PubMed

Missikpode, Celestin; Peek-Asa, Corinne; Young, Tracy; Hamann, Cara

2018-04-01

Emergency vehicles, such as police, ambulances, and fire vehicles, need to arrive at the scene of emergencies as quickly as possible, and thus they often travel in emergency mode - using their lights and sirens and often bypassing traffic signals. We examined whether travelling in emergency mode increased crash risk among police, ambulance and fire vehicles. We conducted a quasi-induced exposure analysis using data from the Iowa Crash Database for the period of 2005 through 2013. The data are maintained by the Iowa Department of Transportation (IADOT), Office of Driver Services (ODS) and includes all investigating police officer's reports of motor vehicle crashes. The quasi-induced exposure method is an approach to calculate crash risk in the absence of exposure data using vehicles without a contributing cause (did not contribute to the crash) as a proxy for the baseline driving population. From 2005 - 2013, police vehicles were involved in 2406 crashes and ambulances and fire vehicles were involved in 528 crashes. Police vehicles were 1.8 times more likely to crash while driving in emergency mode than usual mode; this was a statistically significant increase. Ambulance and fire vehicles were not more likely to crash in emergency mode compared with usual mode. For police, other factors that contributed to crash risk included gender, age, icy/snowy roads, unpaved roads, and intersections. For ambulances and fire vehicles, other factors that contributed to crash risk included gender, age, weekends, icy/snowy roads and urban locations. Crash risk increased when police vehicles drove with lights and sirens but did not increase for ambulance and fire vehicles. Further research is necessary to develop and evaluate strategies to mitigate crash risk among police vehicles. Cultural approaches which prioritize transportation safety in conjunction with reaching the scene as quickly as possible may be warranted. Copyright © 2018 Elsevier Ltd. All rights reserved.

Unventilated Indoor Coal-Fired Stoves in Guizhou Province, China: Cellular and Genetic Damage in Villagers Exposed to Arsenic in Food and Air

PubMed Central

Zhang, Aihua; Feng, Hong; Yang, Guanghong; Pan, Xueli; Jiang, Xianyao; Huang, Xiaoxin; Dong, Xuexin; Yang, Daping; Xie, Yaxiong; Peng, Luo; Jun, Li; Hu, Changjun; Jian, Li; Wang, Xilan

2007-01-01

Background Inorganic arsenic (iAs) is a well-known human carcinogen recognized by the World Health Organization and the International Agency for Research on Cancer. Currently, most iAs studies in populations are concerned with drinking water and occupational arsenicosis. In Guizhou province, arsenicosis caused by the burning of coal in unventilated indoor stoves is an unusual type of exposure. Because the poisoning mechanism involved in arsenicosis is as yet unknown and no effective therapy exists, progress has been slow on the prevention and therapy of arsenicosis. Objectives We examined the relationship between arsenic (As) exposure from the burning of coal in unventilated indoor stoves and genetic damage in humans, using cellular and molecular indices. We selected villagers from Jiaole township, Guizhou province, China, who had been exposed to milligram levels of As daily via food and air contaminated by the burning of As-containing coal in unventilated indoor stoves. Results The As-exposed subjects from Jiaole were divided into four groups according to skin lesion symptoms: nonpatients, mild, intermediate, and severe arsenicosis. Another 53 villagers from a town 12 km from Jiaole were recruited as the external control group. In the four groups of exposed subjects, As concentrations in urine and hair were 76–145 μg/L and 5.4–7.9 μg/g, respectively. These values were higher than those in the external control group, which had As concentrations of 46 μg/L for urine and 1.6 μg/g for hair. We measured sister chromatid exchange and chromosomal aberrations to determine human chromosome damage, and for DNA damage, we measured DNA single-strand breaks and DNA–protein cross-links. All measurements were higher in the four exposed groups compared with the external control group. DNA repair was impaired by As exposure, as indicated by the mRNA of O-6-methylguanine-DNA methyltransferase (MGMT), X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), and, to a lesser extent, by the mismatch repair gene hMSH2 mRNA. The expression of mutant-type p53 increased with aggravation of arsenicosis symptoms, whereas the expression of p16-INK4(p16) decreased. p53 mutated at a frequency of 30–17% in the carcinoma (n = 10) and precarcinoma (n = 12) groups. No mutation was found in p16, although deletion was evident. Deletion rates were 8.7% (n = 23) and 38.9% (n = 18) in noncarcinoma and carcinoma groups, respectively. Conclusions The results showed that long-term As exposure may be associated with damage of chromosomes and DNA, gene mutations, gene deletions, and alterations of DNA synthesis and repair ability. PMID:17450239

Concomitant behavioral and PFC neuronal activity recorded following dose-response protocol of MPD in adult male rats.

PubMed

Venkataraman, Sidish S; Claussen, Catherine; Joseph, Michael; Dafny, Nachum

2017-04-01

The use of methylphenidate (MPD), a commonly prescribed drug to treat attention-deficit hyperactivity disorder (ADHD), has steadily increased over the past 25 years. This trend has been accompanied by more MPD abuse by ordinary individuals for its cognitive enhancing effects. Therefore, understanding the effects of MPD on the prefrontal cortex (PFC), a brain area involved in higher cortical processing such as executive function, language, planning, and attention regulation, is of particular importance. The goal of this study is to investigate the effects of acute and chronic dose-response characteristics following MPD exposure on both the PFC neuronal population and behavioral activity in freely behaving animals implanted previously with permanent electrodes within the PFC. Four groups of animals were used: saline (control), 0.6, 2.5, and 10.0mg/kg MPD. It was observed that the same dose of either 0.6, 2.5, or 10.0mg/kg repetitive (chronic) MPD exposure elicited behavioral sensitization in some animals and behavioral tolerance in others, and that the majority of PFC units recorded from animals expressing behavioral sensitization to chronic MPD exposure responded to MPD by increasing their neuronal firing rate, whereas the majority of PFC neurons recorded from animals expressing behavioral tolerance in response to chronic MPD responded by decreasing their neuronal firing rate. This data suggests that in animals that display behavioral sensitization, chronic MPD exposure causes an increase in the number of post-synaptic D1 dopamine receptors leading to an increase in behavioral and neuronal firing rate, while in animals that display behavioral tolerance, chronic MPD exposure causes an increase in the number of post-synaptic D2 dopamine receptors leading to a decrease in behavioral and neuronal firing rate. This dichotomy needs to be further investigated. Copyright © 2017 Elsevier Inc. All rights reserved.

Proinflammatory effects of cookstove emissions on human bronchial epithelial cells.

PubMed

Hawley, B; Volckens, J

2013-02-01

Approximately half of the world's population uses biomass fuel for indoor cooking and heating. This form of combustion typically occurs in open fires or primitive stoves. Human exposure to emissions from indoor biomass combustion is a global health concern, causing an estimated 1.5 million premature deaths each year. Many 'improved' stoves have been developed to address this concern; however, studies that examine exposure-response with cleaner-burning, more efficient stoves are few. The objective of this research was to evaluate the effects of traditional and cleaner-burning stove emissions on an established model of the bronchial epithelium. We exposed well-differentiated, normal human bronchial epithelial cells to emissions from a single biomass combustion event using either a traditional three-stone fire or one of two energy-efficient stoves. Air-liquid interface cultures were exposed using a novel, aerosol-to-cell deposition system. Cellular expression of a panel of three pro-inflammatory markers was evaluated at 1 and 24 h following exposure. Cells exposed to emissions from the cleaner-burning stoves generated significantly fewer amounts of pro-inflammatory markers than cells exposed to emissions from a traditional three-stone fire. Particulate matter emissions from each cookstove were substantially different, with the three-stone fire producing the largest concentrations of particles (by both number and mass). This study supports emerging evidence that more efficient cookstoves have the potential to reduce respiratory inflammation in settings where solid fuel combustion is used to meet basic domestic needs. Emissions from more efficient, cleaner-burning cookstoves produced less inflammation in well-differentiated bronchial lung cells. The results support evidence that more efficient cookstoves can reduce the health burden associated with exposure to indoor pollution from the combustion of biomass. © 2012 John Wiley & Sons A/S.

Wildfire exposure and fuel management on western US national forests.

PubMed

Ager, Alan A; Day, Michelle A; McHugh, Charles W; Short, Karen; Gilbertson-Day, Julie; Finney, Mark A; Calkin, David E

2014-12-01

Substantial investments in fuel management activities on national forests in the western US are part of a national strategy to reduce human and ecological losses from catastrophic wildfire and create fire resilient landscapes. Prioritizing these investments within and among national forests remains a challenge, partly because a comprehensive assessment that establishes the current wildfire risk and exposure does not exist, making it difficult to identify national priorities and target specific areas for fuel management. To gain a broader understanding of wildfire exposure in the national forest system, we analyzed an array of simulated and empirical data on wildfire activity and fuel treatment investments on the 82 western US national forests. We first summarized recent fire data to examine variation among the Forests in ignition frequency and burned area in relation to investments in fuel reduction treatments. We then used simulation modeling to analyze fine-scale spatial variation in burn probability and intensity. We also estimated the probability of a mega-fire event on each of the Forests, and the transmission of fires ignited on national forests to the surrounding urban interface. The analysis showed a good correspondence between recent area burned and predictions from the simulation models. The modeling also illustrated the magnitude of the variation in both burn probability and intensity among and within Forests. Simulated burn probabilities in most instances were lower than historical, reflecting fire exclusion on many national forests. Simulated wildfire transmission from national forests to the urban interface was highly variable among the Forests. We discuss how the results of the study can be used to prioritize investments in hazardous fuel reduction within a comprehensive multi-scale risk management framework. Published by Elsevier Ltd.

Nuclear Winter: Global Consequences of Multiple Nuclear Explosions

NASA Astrophysics Data System (ADS)

Turco, R. P.; Toon, O. B.; Ackerman, T. P.; Pollack, J. B.; Sagan, Carl

1983-12-01

The potential global atmospheric and climatic consequences of nuclear war are investigated using models previously developed to study the effects of volcanic eruptions. Although the results are necessarily imprecise, due to a wide range of possible scenarios and uncertainty in physical parameters, the most probable first-order effects are serious. Significant hemispherical attenuation of the solar radiation flux and subfreezing land temperatures may be caused by fine dust raised in high-yield nuclear surface bursts and by smoke from city and forest fires ignited by airbursts of all yields. For many simulated exchanges of several thousand megatons, in which dust and smoke are generated and encircle the earth within 1 to 2 weeks, average light levels can be reduced to a few percent of ambient and land temperatures can reach -15 degrees to -25 degrees C. The yield threshold for major optical and climatic consequences may be very low: only about 100 megatons detonated over major urban centers can create average hemispheric smoke optical depths greater than 2 for weeks and, even in summer, subfreezing land temperatures for months. In a 5000-megaton war, at northern mid-latitude sites remote from targets, radioactive fallout on time scales of days to weeks can lead to chronic mean doses of up to 50 rads from external whole-body gamma-ray exposure, with a likely equal or greater internal dose from biologically active radionuclides. Large horizontal and vertical temperature gradients caused by absorption of sunlight in smoke and dust clouds may greatly accelerate transport of particles and radioactivity from the Northern Hemisphere to the Southern Hemisphere. When combined with the prompt destruction from nuclear blast, fires, and fallout and the later enhancement of solar ultraviolet radiation due to ozone depletion, long-term exposure to cold, dark, and radioactivity could pose a serious threat to human survivors and to other species.

Health Impacts of Climate Change-Induced Subzero Temperature Fires.

PubMed

Metallinou, Maria-Monika; Log, Torgrim

2017-07-20

General fire risk and the special risk related to cold climate cellulosic drying processes are outlined. Four recent subzero temperatures fires are studied with respect to health impacts: a wooden village fire, a single wood structure fire, a wildland urban interface (WUI) fire and a huge wildland fire. The health impacts range from stress related to loss of jobs, psychological effects of lost possessions, exposure to smoke and heat as well as immediate, or delayed, loss of lives. These four fires resulted in 32 fatalities, 385 persons hospitalized for shorter or longer periods, 104 structures lost and 1015 km² of wildland burned north of, and just south of, the Arctic Circle. It is shown that the combination of subzero temperature dry weather, strong winds, changing agricultural activities and declining snowpack may lead to previously anticipated threats to people and the environment. There are reasons to believe that these fires are a result of the ongoing climate changes. Risk impacts are discussed. Rural districts and/or vulnerable populations seem to be most affected. Training methods to identify and better monitor critical fire risk parameters are suggested to mitigate the health impacts of a possibly increasing number of such fires.

Health Impacts of Climate Change-Induced Subzero Temperature Fires

PubMed Central

Metallinou, Maria-Monika; Log, Torgrim

2017-01-01

General fire risk and the special risk related to cold climate cellulosic drying processes are outlined. Four recent subzero temperatures fires are studied with respect to health impacts: a wooden village fire, a single wood structure fire, a wildland urban interface (WUI) fire and a huge wildland fire. The health impacts range from stress related to loss of jobs, psychological effects of lost possessions, exposure to smoke and heat as well as immediate, or delayed, loss of lives. These four fires resulted in 32 fatalities, 385 persons hospitalized for shorter or longer periods, 104 structures lost and 1015 km2 of wildland burned north of, and just south of, the Arctic Circle. It is shown that the combination of subzero temperature dry weather, strong winds, changing agricultural activities and declining snowpack may lead to previously anticipated threats to people and the environment. There are reasons to believe that these fires are a result of the ongoing climate changes. Risk impacts are discussed. Rural districts and/or vulnerable populations seem to be most affected. Training methods to identify and better monitor critical fire risk parameters are suggested to mitigate the health impacts of a possibly increasing number of such fires. PMID:28726752

The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, U.S.A.

PubMed

Fraver, Shawn; Jain, Theresa; Bradford, John B; D'Amato, Anthony W; Kastendick, Doug; Palik, Brian; Shinneman, Doug; Stanovick, John

2011-09-01

Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and wildfire-provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions.

The efficacy of salvage logging in reducing subsequent fire severity in conifer-dominated forests of Minnesota, USA

USGS Publications Warehouse

Fraver, S.; Jain, T.; Bradford, J.B.; D'Amato, A.W.; Kastendick, D.; Palik, B.; Shinneman, D.; Stanovick, J.

2011-01-01

Although primarily used to mitigate economic losses following disturbance, salvage logging has also been justified on the basis of reducing fire risk and fire severity; however, its ability to achieve these secondary objectives remains unclear. The patchiness resulting from a sequence of recent disturbances-blowdown, salvage logging, and ildfire- provided an excellent opportunity to assess the impacts of blowdown and salvage logging on wildfire severity. We used two fire-severity assessments (tree-crown and forest-floor characteristics) to compare post-wildfire conditions among three treatment combinations (Blowdown-Salvage-Fire, Blowdown-Fire, and Fire only). Our results suggest that salvage logging reduced the intensity (heat released) of the subsequent fire. However, its effect on severity (impact to the system) differed between the tree crowns and forest floor: tree-crown indices suggest that salvage logging decreased fire severity (albeit with modest statistical support), while forest-floor indices suggest that salvage logging increased fire severity. We attribute the latter finding to the greater exposure of mineral soil caused by logging operations; once exposed, soils are more likely to register the damaging effects of fire, even if fire intensity is not extreme. These results highlight the important distinction between fire intensity and severity when formulating post-disturbance management prescriptions. ?? 2011 by the Ecological Society of America.

Exposure of Firefighters to Particulates and Polycyclic Aromatic Hydrocarbons

PubMed Central

Baxter, C. Stuart; Hoffman, Joseph D.; Knipp, Michael J.; Reponen, Tiina; Haynes, Erin N.

2015-01-01

Firefighting continues to be among the most hazardous yet least studied occupations in terms of exposures and their relationship to occupational disease. Exposures are complex, involving mixtures of particles and chemicals such as polycyclic aromatic hydrocarbons (PAHs). Adverse health effects associated with these agents include elevated incidences of coronary heart disease and several cancers. PAHs have been detected at fire scenes, and in the firehouse rest area and kitchen, routinely adjoining the truck bay, and where firefighters spend a major part of each shift. An academic-community partnership was developed with the Cincinnati Fire Department with the goal of understanding active firefighters' airborne and dermal PAH exposure. PAHs were measured in air and particulates, and number and mass concentrations, respectively, of submicron (0.02–1 μm) and PM2.5 (2.5 μm diameter and less) particles during overhaul events in two firehouses and a University of Cincinnati administrative facility as a comparison location. During overhaul firefighters evaluate partially combusted materials for re-ignition after fire extinguishment and commonly remove Self-Contained Breathing Apparatus (SCBA). Face and neck wipes were also collected at a domestic fire scene. Overhaul air samples had higher mean concentrations of PM2.5 and submicron particles than those collected in the firehouse, principally in the truck bay and kitchen. Among the 17 PAHs analyzed, only naphthalene and acenaphthylene were generally detectable. Naphthalene was present in 7 out of 8 overhaul activities, in 2 out of 3 firehouse (kitchen and truck bay) samples, and in none collected from the control site. In firefighter face and neck wipes a greater number of PAHs were found, several of which have carcinogenic activity, such as benzofluoranthene, an agent also found in overhaul air samples. Although the concentration for naphthalene, and all other individual PAHs, was very low, the potential simultaneous exposure to multiple chemicals even in small quantities in combination with high ultrafine particle exposure deserves further study. It is recommended that personal respiratory and skin protection be worn throughout the overhaul process. PMID:24512044

Physiological and behavioral responses of an arboreal mammal to smoke and charcoal-ash substrate.

PubMed

Nowack, Julia; Stawski, Clare; Körtner, Gerhard; Geiser, Fritz

2018-02-01

The recent observation that torpor plays a key role in post-fire survival has been mainly attributed to the reduced food resources after fires. However, some of these adjustments can be facilitated or amplified by environmental changes associated with fires, such as the presence of a charcoal-ash substrate. In a previous experiment on a small terrestrial mammal the presence of charcoal and ash linked to food restriction intensified torpor use. However, whether fire cues also act as a trigger of torpor use when food is available and whether they affect other species including arboreal mammals remains elusive. To evaluate whether smoke, charcoal and ash can act as proximate triggers for an impending period of food shortage requiring torpor for mammals, we conducted an experiment on captive sugar gliders (Petaurus breviceps), a small, arboreal marsupial, housed in outside aviaries under different food regimes and natural ambient conditions. When food was available, fire simulation via exposure to smoke and charcoal-ash substrate caused a significant earlier start of activity and a significant decrease in resting body temperature. In contrast, only when food was withheld, did smoke and charcoal-ash exposure significantly enhance torpor depth and duration. Thus, our study not only provides evidence that fire simulation does affect arboreal and terrestrial species similarly, but also suggests that smoke and ash were presumably selected as cues for torpor induction because they indicate an impending lack of food. Copyright © 2017 Elsevier Inc. All rights reserved.

Fire propagation performance of intumescent fire protective coatings using eggshells as a novel biofiller.

PubMed

Yew, M C; Ramli Sulong, N H; Yew, M K; Amalina, M A; Johan, M R

2014-01-01

This paper aims to synthesize and characterize an effective intumescent fire protective coating that incorporates eggshell powder as a novel biofiller. The performances of thermal stability, char formation, fire propagation, water resistance, and adhesion strength of coatings have been evaluated. A few intumescent flame-retardant coatings based on these three ecofriendly fire retardant additives ammonium polyphosphate phase II, pentaerythritol and melamine mixed together with flame-retardant fillers, and acrylic binder have been prepared and designed for steel. The fire performance of the coatings has conducted employing BS 476: Part 6-Fire propagation test. The foam structures of the intumescent coatings have been observed using field emission scanning electron microscopy. On exposure, the coated specimens' B, C, and D had been certified to be Class 0 due to the fact that their fire propagation indexes were less than 12. Incorporation of ecofriendly eggshell, biofiller into formulation D led to excellent performance in fire stopping (index value, (I) = 4.3) and antioxidation of intumescent coating. The coating is also found to be quite effective in water repellency, uniform foam structure, and adhesion strength.

Fire Propagation Performance of Intumescent Fire Protective Coatings Using Eggshells as a Novel Biofiller

PubMed Central

Yew, M. C.; Ramli Sulong, N. H.; Yew, M. K.; Amalina, M. A.; Johan, M. R.

2014-01-01

This paper aims to synthesize and characterize an effective intumescent fire protective coating that incorporates eggshell powder as a novel biofiller. The performances of thermal stability, char formation, fire propagation, water resistance, and adhesion strength of coatings have been evaluated. A few intumescent flame-retardant coatings based on these three ecofriendly fire retardant additives ammonium polyphosphate phase II, pentaerythritol and melamine mixed together with flame-retardant fillers, and acrylic binder have been prepared and designed for steel. The fire performance of the coatings has conducted employing BS 476: Part 6-Fire propagation test. The foam structures of the intumescent coatings have been observed using field emission scanning electron microscopy. On exposure, the coated specimens' B, C, and D had been certified to be Class 0 due to the fact that their fire propagation indexes were less than 12. Incorporation of ecofriendly eggshell, biofiller into formulation D led to excellent performance in fire stopping (index value, (I) = 4.3) and antioxidation of intumescent coating. The coating is also found to be quite effective in water repellency, uniform foam structure, and adhesion strength. PMID:25136687

COMMUNITY VIOLENCE AND EXTERNALIZING PROBLEMS: MODERATING EFFECTS OF RACE AND RELIGIOSITY IN EMERGING ADULTHOOD

PubMed Central

Fowler, Patrick J.; Ahmed, Sawssan R.; Tompsett, Carolyn J.; Jozefowicz-Simbeni, Debra M. H.; Toro, Paul A.

2009-01-01

The present study examined racial differences in the relationship between exposure to community violence and public and private religiosity in predicting externalizing problems among at-risk emerging adults. Participants were 178 African American and 163 European American emerging adults at risk for exposure to community violence. Exposure to community violence related to more externalizing problems. Greater public religious affiliation buffered the relationship between community violence and substance abuse, for both African American and European emerging adults. In addition, more privately religious African American emerging adults engaged in less deviant behavior when exposed to higher levels of community violence. European Americans were not protected by private religiosity. PMID:20016764

Fire tests to evaluate the potential fire threat and its effects on HEPA filter integrity in cell ventilation at the Oak Ridge National Laboratory, Building 7920

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

Hasegawa, H.K.; Staggs, K.J.; Doughty, S.M.

1992-12-01

As a result of a DOE (Tiger Team) Technical Safety Appraisal (November 1990) of the Radiochemical Engineering Development Center (REDC), ORNL Building 7920, a number of fire protection concerns were identified. The primary concern was the perceived loss of ventilation system containment due to the thermal destruction and/or breaching of the prefilters and/or high-efficiency particulate air filters (HEPA `s) and the resultant radioactive release to the external environment. The following report describes the results of an extensive fire test program performed by the Fire Research Discipline (FRD) of the Special Projects Division of Lawrence Livermore National Lab (LLNL) and fundedmore » by ORNL to address these concerns. Full scale mock-ups of a REDC hot cell tank pit, adjacent cubicle pit, and associated ventilation system were constructed at LLNL and 13 fire experiments were conducted to specifically answer the questions raised by the Tiger Team. Our primary test plan was to characterize the burning of a catastrophic solvent spill (kerosene) of 40 liters and its effect on the containment ventilation system prefilters and HEPA filters. In conjunction with ORNL and Lockwood Greene we developed a test matrix that assessed the fire performance of the prefilters and HEPA filters; evaluated the fire response of the fiber reinforced plastic (FRP) epoxy ventilation duct work; the response and effectiveness of the fire protection system, the effect of fire in a cubicle on the vessel off-gas (VOG) elbow, and other fire safety questions.« less

Network analysis of wildfire transmission and implications for risk governance

Treesearch

Alan A. Ager; Cody R. Evers; Michelle A. Day; Haiganoush K. Preisler; Ana M. G. Barros; Max Nielsen-Pincus

2017-01-01

We characterized wildfire transmission and exposure within a matrix of large land tenures (federal, state, and private) surrounding 56 communities within a 3.3 million ha fire prone region of central Oregon US. Wildfire simulation and network analysis were used to quantify the exchange of fire among land tenures and communities and analyze the relative contributions of...

Post-Fire Analysis of Solid-Sawn Heavy Timber Beams

Treesearch

Robert H. White; Frank E. Woeste

2013-01-01

After fire exposure, design professionals are sometimes called upon to determine if the charred heavy timbers (Figure 1) are safe for future use without additional support or repairs. In this article, the authors present a sequence of reasoned steps that will help design professionals analyze charred timbers and gain the type of information needed to...

Exploring how alternative mapping approaches influence fireshed assessment and human community exposure to wildfire

Treesearch

Joe H. Scott; Matthew P. Thompson; Julie W. Gilbertson-Day

2015-01-01

Attaining fire-adapted human communities has become a key focus of collaborative planning on landscapes across the western United States and elsewhere. The coupling of fire simulation with GIS has expanded the analytical base to support such planning efforts, particularly through the "fireside" concept that identifies areas where wildfires could ignite and...

Getting ahead of the wildfire problem: Quantifying and mapping management challenges and opportunities

Treesearch

Christopher D. O' Connor; Matthew P. Thompson; Francisco Rodriguez y Silva

2016-01-01

Wildfire is a global phenomenon that plays a vital role in regulating and maintaining many natural and human-influenced ecosystems but that also poses considerable risks to human populations and infrastructure. Fire managers are charged with balancing the short-term protection of human assets sensitive to fire exposure against the potential long-term benefits...

Measurement methods for human exposure analysis.

PubMed Central

Lioy, P J

1995-01-01

The general methods used to complete measurements of human exposures are identified and illustrations are provided for the cases of indirect and direct methods used for exposure analysis. The application of the techniques for external measurements of exposure, microenvironmental and personal monitors, are placed in the context of the need to test hypotheses concerning the biological effects of concern. The linkage of external measurements to measurements made in biological fluids is explored for a suite of contaminants. This information is placed in the context of the scientific framework used to conduct exposure assessment. Examples are taken from research on volatile organics and for a large scale problem: hazardous waste sites. PMID:7635110

Fire characteristics associated with firefighter injury on large federal wildland fires.

PubMed

Britton, Carla; Lynch, Charles F; Torner, James; Peek-Asa, Corinne

2013-02-01

Wildland fires present many injury hazards to firefighters. We estimate injury rates and identify fire-related factors associated with injury. Data from the National Interagency Fire Center from 2003 to 2007 provided the number of injuries in which the firefighter could not return to his or her job assignment, person-days worked, and fire characteristics (year, region, season, cause, fuel type, resistance to control, and structures destroyed). We assessed fire-level risk factors of having at least one reported injury using logistic regression. Negative binomial regression was used to examine incidence rate ratios associated with fire-level risk factors. Of 867 fires, 9.5% required the most complex management and 24.7% required the next-highest level of management. Fires most often occurred in the western United States (82.8%), during the summer (69.6%), caused by lightening (54.9%). Timber was the most frequent fuel source (40.2%). Peak incident management level, person-days of exposure, and the fire's resistance to control were significantly related to the odds of a fire having at least one reported injury. However, the most complex fires had a lower injury incidence rate than less complex fires. Although fire complexity and the number of firefighters were associated with the risk for at least one reported injury, the more experienced and specialized firefighting teams had lower injury incidence. Copyright © 2013 Elsevier Inc. All rights reserved.

n/a

NASA Image and Video Library

1977-09-09

The first Space Shuttle External Tank, the Main Propulsion Test Article (MPTA), rolls off the assembly line September 9, 1977 at the Michoud Assembly Facility in New Orleans. The MPTA was then transported to the National Space Technology Laboratories in southern Mississippi where it was used in the first static firing of the three main engines. Marshall Space Flight Center had management responsibility for Space Shuttle propulsion elements, including the External Tank. Martin Marietta was the prime contractor who designed and assembled the tanks at Michoud.

Community vulnerability to health impacts of wildland fire smoke exposure

EPA Science Inventory

Identifying communities vulnerable to adverse health effects from exposure to wildfire smoke may help prepare responses, increase the resilience to smoke and improve public health outcomes during smoke days. We developed a Community Health-Vulnerability Index (CHVI) based on fact...

Effect of reducing indoor air pollution on women's respiratory symptoms and lung function: the RESPIRE Randomized Trial, Guatemala.

PubMed

Smith-Sivertsen, Tone; Díaz, Esperanza; Pope, Dan; Lie, Rolv T; Díaz, Anaite; McCracken, John; Bakke, Per; Arana, Byron; Smith, Kirk R; Bruce, Nigel

2009-07-15

Exposure to household wood smoke from cooking is a risk factor for chronic obstructive lung disease among women in developing countries. The Randomized Exposure Study of Pollution Indoors and Respiratory Effects (RESPIRE) is a randomized intervention trial evaluating the respiratory health effects of reducing indoor air pollution from open cooking fires. A total of 504 rural Mayan women in highland Guatemala aged 15-50 years, all using traditional indoor open fires, were randomized to either receive a chimney woodstove (plancha) or continue using the open fire. Assessments of chronic respiratory symptoms and lung function and individual measurements of carbon monoxide exposure were performed at baseline and every 6 months up to 18 months. Use of a plancha significantly reduced carbon monoxide exposure by 61.6%. For all respiratory symptoms, reductions in risk were observed in the plancha group during follow-up; the reduction was statistically significant for wheeze (relative risk = 0.42, 95% confidence interval: 0.25, 0.70). The number of respiratory symptoms reported by the women at each follow-up point was also significantly reduced by the plancha (odds ratio = 0.7, 95% confidence interval: 0.50, 0.97). However, no significant effects on lung function were found after 12-18 months. Reducing indoor air pollution from household biomass burning may relieve symptoms consistent with chronic respiratory tract irritation.

[Mind the explosion? The evolution of safety at work in anaesthesiology].

PubMed

Petermann, Heike

2015-11-01

The evolution of safety in anaesthesiology is characterized by 2 aspects: exposure of anaesthetic staff by volatile anaesthetics and fire as well as explosions in combination with those. In the 20th century, the exposure of staff in the operating room became more and more important. Trigger for the fatal complications were gas lights in combination with chloroform. Later oxygen and inhalation anaesthetics caused explosions and fires. Therefore safety rules were implemented in the 1980s in the Federal Republic of Germany. These were valid for application anaesthetics including apparatus and configuration of operating rooms. The only imponderability is still the human factor.

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

Jones, Daniel Steven; Efroymson, Rebecca Ann; Hargrove, William Walter

A multiple stressor risk assessment was conducted at Yuma Proving Ground, Arizona, as a demonstration of the Military Ecological Risk Assessment Framework. The focus was a testing program at Cibola Range, which involved an Apache Longbow helicopter firing Hellfire missiles at moving targets, M60- A1 tanks. This paper describes the ecological risk assessment for the missile launch and detonation. The primary stressor associated with this activity was sound. Other minor stressors included the detonation impact, shrapnel, and fire. Exposure to desert mule deer (Odocoileus hemionus crooki) was quantified using the Army sound contour program BNOISE2, as well as distances frommore » the explosion to deer. Few effects data were available from related studies. Exposure-response models for the characterization of effects consisted of human "disturbance" and hearing damage thresholds in units of C-weighted decibels (sound exposure level) and a distance-based No Observed Adverse Effects Level for moose and cannonfire. The risk characterization used a weight-of-evidence approach and concluded that risk to mule deer behavior from the missile firing was likely for a negligible number of deer, but that no risk to mule deer abundance and reproduction is expected.« less

Parallel and convergent processing in grid cell, head-direction cell, boundary cell, and place cell networks

PubMed Central

Brandon, Mark P; Koenig, Julie; Leutgeb, Stefan

2014-01-01

The brain is able to construct internal representations that correspond to external spatial coordinates. Such brain maps of the external spatial topography may support a number of cognitive functions, including navigation and memory. The neuronal building block of brain maps are place cells, which are found throughout the hippocampus of rodents and, in a lower proportion, primates. Place cells typically fire in one or few restricted areas of space, and each area where a cell fires can range, along the dorsoventral axis of the hippocampus, from 30 cm to at least several meters. The sensory processing streams that give rise to hippocampal place cells are not fully understood, but substantial progress has been made in characterizing the entorhinal cortex, which is the gateway between neocortical areas and the hippocampus. Entorhinal neurons have diverse spatial firing characteristics, and the different entorhinal cell types converge in the hippocampus to give rise to a single, spatially modulated cell type—the place cell. We therefore suggest that parallel information processing in different classes of cells—as is typically observed at lower levels of sensory processing—continues up into higher level association cortices, including those that provide the inputs to hippocampus. WIREs Cogn Sci 2014, 5:207–219. doi: 10.1002/wcs.1272 PMID:24587849

Radiation Risks of Leukemia, Lymphoma and Multiple Myeloma Incidence in the Mayak Cohort: 1948–2004

PubMed Central

Kuznetsova, Irina S.; Labutina, Elena V.; Hunter, Nezahat

2016-01-01

Incidence of all types of lymphatic and hematopoietic cancers, including Hodgkin’s lymphoma, non-Hodgkin's lymphoma, multiple myeloma, acute and chronic myeloid leukemia (AML and CML respectively), chronic lymphocytic leukemia (CLL) and other forms of leukemia have been studied in a cohort of 22,373 workers employed at the Mayak Production Association (PA) main facilities during 536,126 person-years of follow-up from the start of employment between 1948 and 1982 to the end of 2004. Risk assessment was performed for both external gamma-radiation and internal alpha-exposure of red bone marrow due to incorporated Pu-239 using Mayak Workers Dosimetry System 2008 taking into account non-radiation factors. The incidence of leukemia excluding CLL showed a non-linear dose response relationship for external gamma exposure with exponential effect modifiers based on time since exposure and age at exposure. Among the major subtypes of leukemia, the excess risk of AML was the highest within the first 2–5 years of external exposure (ERR per Gy: 38.40; 90% CI: 13.92–121.4) and decreased substantially thereafter, but the risks remained statistically significant (ERR per Gy: 2.63; 90% CI: 0.07–12.55). In comparison, excess CML first occurred 5 years after exposure and decreased about 10 years after exposure, although the association was not statistically significant (ERR per Gy: 1.39; 90% CI: -0.22–7.32). The study found no evidence of an association between leukemia and occupational exposure to internal plutonium ERR per Gy 2.13; 90% CI: <0–9.45). There was also no indication of any relationship with either external gamma or internal plutonium radiation exposure for either incidence of Hodgkin or non-Hodgkin lymphoma or multiple myeloma. PMID:27631102

Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane.

PubMed

Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

2016-03-05

This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m² and 16.39 kW/m² for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m². The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation.

Experimental Study of Fire Hazards of Thermal-Insulation Material in Diesel Locomotive: Aluminum-Polyurethane

PubMed Central

Zhang, Taolin; Zhou, Xiaodong; Yang, Lizhong

2016-01-01

This work investigated experimentally and theoretically the fire hazards of thermal-insulation materials used in diesel locomotives under different radiation heat fluxes. Based on the experimental results, the critical heat flux for ignition was determined to be 6.15 kW/m2 and 16.39 kW/m2 for pure polyurethane and aluminum-polyurethane respectively. A theoretical model was established for both to predict the fire behaviors under different circumstances. The fire behavior of the materials was evaluated based on the flashover and the total heat release rate (HRR). The fire hazards levels were classified based on different experimental results. It was found that the fire resistance performance of aluminum-polyurethane is much better than that of pure-polyurethane under various external heat fluxes. The concentration of toxic pyrolysis volatiles generated from aluminum-polyurethane materials is much higher than that of pure polyurethane materials, especially when the heat flux is below 50 kW/m2. The hazard index HI during peak width time was proposed based on the comprehensive impact of time and concentrations. The predicted HI in this model coincides with the existed N-gas and FED models which are generally used to evaluate the fire gas hazard in previous researches. The integrated model named HNF was proposed as well to estimate the fire hazards of materials by interpolation and weighted average calculation. PMID:28773295

Cardiovascular reactivity as a mechanism linking child trauma to adolescent psychopathology.

PubMed

Heleniak, Charlotte; McLaughlin, Katie A; Ormel, Johan; Riese, Harriette

2016-10-01

Alterations in physiological reactivity to stress are argued to be central mechanisms linking adverse childhood environmental experiences to internalizing and externalizing psychopathology. Childhood trauma exposure may influence physiological reactivity to stress in distinct ways from other forms of childhood adversity. This study applied a novel theoretical model to investigate the impact of childhood trauma on cardiovascular stress reactivity - the biopsychosocial model of challenge and threat. This model suggests that inefficient cardiovascular responses to stress - a threat as opposed to challenge profile - are characterized by blunted cardiac output (CO) reactivity and increased vascular resistance. We examined whether childhood trauma exposure predicted an indicator of the threat profile of cardiovascular reactivity and whether such a pattern was associated with adolescent psychopathology in a population-representative sample of 488 adolescents (M=16.17years old, 49.2% boys) in the TRacking Adolescents' Individual Lives Survey (TRAILS). Exposure to trauma was associated with both internalizing and externalizing symptoms and a pattern of cardiovascular reactivity consistent with the threat profile, including blunted CO reactivity during a social stress task. Blunted CO reactivity, in turn, was positively associated with externalizing, but not internalizing symptoms and mediated the link between trauma and externalizing psychopathology. None of these associations varied by gender. The biopsychosocial model of challenge and threat provides a novel theoretical framework for understanding disruptions in physiological reactivity to stress following childhood trauma exposure, revealing a potential pathway linking such exposure with externalizing problems in adolescents. Copyright © 2016 Elsevier B.V. All rights reserved.

Cardiovascular reactivity as a mechanism linking child trauma to adolescent psychopathology

PubMed Central

Heleniak, Charlotte; McLaughlin, Katie A.; Ormel, Johan; Riese, Harriette

2016-01-01

Alterations in physiological reactivity to stress are argued to be central mechanisms linking adverse childhood environmental experiences to internalizing and externalizing psychopathology. Childhood trauma exposure may influence physiological reactivity to stress in distinct ways from other forms of childhood adversity. This study applied a novel theoretical model to investigate the impact of childhood trauma on cardiovascular stress reactivity – the biopsychosocial model of challenge and threat. This model suggests that inefficient cardiovascular responses to stress – a threat as opposed to challenge profile – are characterized by blunted cardiac output (CO) reactivity and increased vascular resistance. We examined whether childhood trauma exposure predicted an indicator of the threat profile of cardiovascular reactivity and whether such a pattern was associated with adolescent psychopathology in a population-representative sample of 488 adolescents (M = 16.17 years old, 49.2% boys) in the TRacking Adolescents’ Individual Lives Survey (TRAILS). Exposure to trauma was associated with both internalizing and externalizing symptoms and a pattern of cardiovascular reactivity consistent with the threat profile, including blunted CO reactivity during a social stress task. Blunted CO reactivity, in turn, was positively associated with externalizing, but not internalizing symptoms and mediated the link between trauma and externalizing psychopathology. None of these associations varied by gender. The biopsychosocial model of challenge and threat provides a novel theoretical framework for understanding disruptions in physiological reactivity to stress following childhood trauma exposure, revealing a potential pathway linking such exposure with externalizing problems in adolescents. PMID:27568327

Can earthworms survive fire retardants?

USGS Publications Warehouse

Beyer, W.N.; Olson, A.

1996-01-01

Most common fire retardants are foams or are similar to common agricultural fertilizers, such as ammonium sulfate and ammonium phosphate. Although fire retardants are widely applied to soils, we lack basic information about their toxicities to soil organisms. We measured the toxicity of five fire retardants (Firetrol LCG-R, Firetrol GTS-R, Silv-Ex Foam Concentrate, Phos-chek D-75, and Phos-chek WD-881) to earthworms using the pesticide toxicity test developed for earthworms by the European Economic Community. None was lethal at 1,000 ppm in the soil, which was suggested as a relatively high exposure under normal applications. We concluded that the fire retardants tested are relatively nontoxic to soil organisms compared with other environmental chemicals and that they probably do not reduce earthworm populations when applied under usual firefighting conditions.

Verification study of an emerging fire suppression system

DOE PAGES

Cournoyer, Michael E.; Waked, R. Ryan; Granzow, Howard N.; ...

2016-01-01

Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Moreover, plutonium gloveboxes present harsh environmental conditions for polymer materials; these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. Several studies have been conducted to determine the robustness of selfcontained fire extinguishers in plutonium gloveboxes in a nuclear facility, verification tests must be performed. These tests include activation and mass loss calorimeter tests. In addition, compatibility issues with chemical components of the self-contained fire extinguishers need to be addressed. Our study presents activation andmore » mass loss calorimeter test results. After extensive studies, no critical areas of concern have been identified for the plutonium glovebox application of Fire Foe™, except for glovebox operations that use large quantities of bulk plutonium or uranium metal such as metal casting and pyro-chemistry operations.« less

Verification study of an emerging fire suppression system

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

Cournoyer, Michael E.; Waked, R. Ryan; Granzow, Howard N.

Self-contained fire extinguishers are a robust, reliable and minimally invasive means of fire suppression for gloveboxes. Moreover, plutonium gloveboxes present harsh environmental conditions for polymer materials; these include radiation damage and chemical exposure, both of which tend to degrade the lifetime of engineered polymer components. Several studies have been conducted to determine the robustness of selfcontained fire extinguishers in plutonium gloveboxes in a nuclear facility, verification tests must be performed. These tests include activation and mass loss calorimeter tests. In addition, compatibility issues with chemical components of the self-contained fire extinguishers need to be addressed. Our study presents activation andmore » mass loss calorimeter test results. After extensive studies, no critical areas of concern have been identified for the plutonium glovebox application of Fire Foe™, except for glovebox operations that use large quantities of bulk plutonium or uranium metal such as metal casting and pyro-chemistry operations.« less

[Time series studies of air pollution by fires and the effects on human health].

PubMed

do Carmo, Cleber Nascimento; Hacon, Sandra de Souza

2013-11-01

Burnoffs (intentional fires for agricultural purposes) and forest fires of large proportions have been observed in various regions of the planet. Exposure to high levels of air pollutants emitted by fires can be responsible for various harmful effects on human health. In this article, the literature on estimating acute effects of air pollution on human health by fires in the regions with the highest number of fires on the planet, using a time series approach is summarized. An attempt was made to identify gaps in knowledge. The study consisted of a narrative review, in which the characteristics of the selected studies were grouped by regions of the planet with a higher incidence of burnoffs: Amazon, America, Australia and Asia. The results revealed a large number of studies in Australia, few studies in the Amazon and great heterogeneity in the results on the significant effects on human health.

The importance of mammalian torpor for survival in a post-fire landscape.

PubMed

Stawski, Clare; Körtner, Gerhard; Nowack, Julia; Geiser, Fritz

2015-06-01

Wildfires have increased in frequency and intensity worldwide with climate change as a main driving factor. While a number of studies have focused on population changes in regard to fires, there are essentially no quantitative data on behavioural and physiological adjustments that are vital for the persistence of individuals during and after fires. Here we show that brown antechinus, a small insectivorous marsupial mammal, (i) endured a prescribed fire in situ, (ii) remained in their scorched home range despite unburned areas nearby, and (iii) substantially increased post-fire torpor use and thus reduced foraging requirements and exposure to predators. Hence, torpor is a physiological adaptation that, although not quantified in this context previously, appears to play a key role in post-fire survival for this and other heterothermic species. © 2015 The Author(s) Published by the Royal Society. All rights reserved.

[Household gas poisonings].

PubMed

Maloca, Ivana; Macan, Jelena; Varnai, Veda Marija; Turk, Rajka

2006-12-01

Exposure to toxic gases which can induce serious health effects, can occur in the working as well as in general environment, including home. The severity of gas poisoning is determined by its physical and chemical characteristics, intensity and duration of exposure, and concomitant diseases and injuries in the poisoned person. Manifestations of gas toxic action involve simple asphyxia, local irritation of respiratory mucosa, systemic toxicity, and a combination of these mechanisms. This article describes the characteristics, modes of exposure and health effects of most common gases causing poisoning at home. These include gas fuels, carbon monoxide, ammonia, chlorine, and fire gases such as nitrogen and sulphur oxides, hydrogen cyanide and phosgene. First aid as well as preventive measures to avoid exposure to toxic gases and prevent fire at home are also given. The Croatian Poison Control Centre gathered data on toxic gas exposures in households between November 2005 and July 2006. During this period 30 persons (3 % of the total number of cases) were exposed to toxic gases at home, including carbon monoxide, irritating vapours from cleaning agents and disinfectants, gas fuels, septic tank gases, tear-gas, and chlorofluorocarbons from refrigerators.

Effects of long-term non-traumatic noise exposure on the adult central auditory system. Hearing problems without hearing loss.

PubMed

Eggermont, Jos J

2017-09-01

It is known that hearing loss induces plastic changes in the brain, causing loudness recruitment and hyperacusis, increased spontaneous firing rates and neural synchrony, reorganizations of the cortical tonotopic maps, and tinnitus. Much less in known about the central effects of exposure to sounds that cause a temporary hearing loss, affect the ribbon synapses in the inner hair cells, and cause a loss of high-threshold auditory nerve fibers. In contrast there is a wealth of information about central effects of long-duration sound exposures at levels ≤80 dB SPL that do not even cause a temporary hearing loss. The central effects for these moderate level exposures described in this review include changes in central gain, increased spontaneous firing rates and neural synchrony, and reorganization of the cortical tonotopic map. A putative mechanism is outlined, and the effect of the acoustic environment during the recovery process is illustrated. Parallels are drawn with hearing problems in humans with long-duration exposures to occupational noise but with clinical normal hearing. Copyright © 2016 Elsevier B.V. All rights reserved.

10 CFR 830.204 - Documented safety analysis.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., and accident conditions, including consideration of natural and man-made external events... radioactive and other hazardous materials, and consideration of the need for analysis of accidents which may... preparedness, fire protection, waste management, and radiation protection; and (6) With respect to a nonreactor...

10 CFR 830.204 - Documented safety analysis.

Code of Federal Regulations, 2014 CFR

2014-01-01

..., and accident conditions, including consideration of natural and man-made external events... radioactive and other hazardous materials, and consideration of the need for analysis of accidents which may... preparedness, fire protection, waste management, and radiation protection; and (6) With respect to a nonreactor...

10 CFR 830.204 - Documented safety analysis.

Code of Federal Regulations, 2013 CFR

2013-01-01

..., and accident conditions, including consideration of natural and man-made external events... radioactive and other hazardous materials, and consideration of the need for analysis of accidents which may... preparedness, fire protection, waste management, and radiation protection; and (6) With respect to a nonreactor...

10 CFR 830.204 - Documented safety analysis.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., and accident conditions, including consideration of natural and man-made external events... radioactive and other hazardous materials, and consideration of the need for analysis of accidents which may... preparedness, fire protection, waste management, and radiation protection; and (6) With respect to a nonreactor...

Smoke exposure among wildland firefighters: a review and discussion of current literature.

Treesearch

Timothy E. Reinhardt; Roger D. Ottmar

1997-01-01

This paper reviews and summarizes literature about smoke exposure and the resulting adverse health effects among wildland firefighters Many studies have been done on this problem between 1973 and 1995 Overall the data indicate that smoke exposure at wildfires and prescribed fires is usually no more than an inconvenience, but on occasion it approaches or exceeds legal...

Mammalian Toxicology Testing: Problem Definition Study, Technical Plan.

DTIC Science & Technology

1981-03-01

Acute Oral Exposure Area, Rzdent 2. Subchrcnic Oral Exposure Area, .odent 3. Chronic Oral Exposure Area, Rodent 4. Subchronic Oral Eposure Area, "og...Alarms Fire Extinguisher First Aid Fiscal Year Record Fixtures (See Jigs, Fixtures & Molds Control System) Food Preparation/Blending Forms Control...Insurance Invoicing (See Bookkeeping) Janitorial Service Jigs, Fixtures & Molds Control System Key Control System Keypunch Control System Label

PARTICULATE ORGANIC CARBON MEASUREMENTS COLLECTED WITH LOW FLOW PERSONAL SAMPLERS

EPA Science Inventory

EPA's National Exposure Research Laboratory and the Research Triangle Institute (RTI) have conducted a particulate matter (PM) personal exposure study in Research Triangle Park, NC. Particulate carbon was sampled with pre-fired quartz filters using low flow PM2.5 samplers (2 L...

The response of smoke detectors to pyrolysis and combustion products from aircraft interior materials

NASA Technical Reports Server (NTRS)

Mckee, R. G.; Alvares, N. J.

1976-01-01

The following projects were completed as part of the effort to develop and test economically feasible fire-resistant materials for interior furnishings of aircraft as well as detectors of incipient fires in passenger and cargo compartments: (1) determination of the sensitivity of various contemporary gas and smoke detectors to pyrolysis and combustion products from materials commonly used in aircraft interiors and from materials that may be used in the future, (2) assessment of the environmental limitations to detector sensitivity and reliability. The tests were conducted on three groups of materials by exposure to the following three sources of exposure: radiant and Meeker burner flame, heated coil, and radiant source only. The first test series used radiant heat and flame exposures on easily obtainable test materials. Next, four materials were selected from the first group and exposed to an incandescent coil to provide the conditions for smoldering combustion. Finally, radiant heat exposures were used on advanced materials that are not readily available.

Toxicity of fire retardant chemicals to aquatic organisms: Progress report

USGS Publications Warehouse

Hamilton, Steven J.; McDonald, Susan F.; Gaikowski, Mark P.; Buhl, Kevin J.; Ramsey, G.S.

1996-01-01

Fire retardants and suppressants used extensively in North America are often applied in environmentally sensitive areas that may contain endangered, threatened, or economically important plant and animal species. We conducted laboratory acute toxicity tests in both hard and soft waters with five commonly used fire control chemicals (Fire Trol LCG-R, Fire-Trol GTS-R, Phos-Chek D-75-F, Phos-Chek WD-881, and Silv-Ex). Organisms used in the tests included two fish (rainbow trout and fathead minnow), two aquatic invertebrates (Daphnia magna and Hyalella azteca), and a green algae (Selenastrum capricornutum). In general, the green algae was substantially more sensitive to the three non-foam fire chemicals than the animals, the Daphnia were the most sensitive test organism in exposures with foams. The two foams (Silv-Ex and Phos-Chek WD-881) had similar toxicity and were more toxic than the three non-foams. Water quality did not seem to modify the toxicity of the five fire chemicals in a consistent manner.

Typologies of intimate partner violence-maternal parenting and children's externalizing problems: The moderating effect of the exposure to other forms of family violence.

PubMed

Lamela, Diogo; Jongenelen, Inês; Pinto, Ricardo; Levendosky, Alytia

2018-07-01

Typologies of IPV and parenting practices in mothers who experienced police-reported IPV remain surprisingly unexplored, in addition to how those typologies are linked with children's externalizing problems. Using data from 162 Portuguese mother-child dyads with a police or child protection services referral of IPV, this study aimed to: (a) identify IPV-parenting typologies; (b) test the associations between typologies and children's externalizing problems, and (c) examine the moderating effect of children's exposure to other forms of family violence in those associations. Using a person-centered approach, two IPV-parenting typologies were found: a spillover typology, with high levels of physical, psychological, and sexual violence and high levels of harsh and inconsistent parenting practices; and a compartmentalized typology, with high levels of physical, psychological, and sexual violence and lower ineffective parenting practices. Results also showed that externalizing symptoms (reported by mothers and teachers) were significantly lower in children of mothers in the compartmentalized typology compared to those in the spillover typology. Children's direct exposure to other forms of family violence moderated this association. Findings suggested that children with a high exposure to other forms of family violence showed the highest levels of externalizing problems when their mothers were classified into the spillover typology, and they exhibited the lowest levels of externalizing problems when their mothers were classified in the compartmentalized typology. Copyright © 2018 Elsevier Ltd. All rights reserved.

Occupational exposure to gases, polycyclic aromatic hydrocarbons and volatile organic compounds in biomass-fired power plants.

PubMed

Jumpponen, M; Rönkkömäki, H; Pasanen, P; Laitinen, J

2013-01-01

The combustion of fuels produces air pollutants in the form of gases, organic compounds, and particulate matter. However, although the environmental aspect of these agents has been examined, workers' exposure to them is still a neglected issue. The purpose of this study was to measure maintenance and ash removal workers' multiple exposures to gases, volatile organic compounds (VOCs) and polycyclic aromatic hydrocarbons (PAHs) during their work tasks in biomass-fired power plants. Our hygienic measurements revealed that carbon monoxide, nitric oxide, ammonia and sulfur dioxide were the most common gases that the workers were exposed to during their tasks. Their average concentrations were 0.45 ppm, 0.06 ppm, 0.11 ppm and 0.42 ppm, respectively. Phenanthrene and naphthalene were the most prominent PAHs. At the same sampling points, the most commonly found VOCs were aromatic and aliphatic hydrocarbons and turpentines. The calculated total PAH concentrations were less than 7% of benzo[a]pyrene's eight-hour occupational exposure limit, and the total VOC concentrations were below the Finnish reference value for the normal industrial level in all measured work tasks. The most evident health effect caused by multiple exposures to gases was upper respiratory track irritation, followed by the disruption of oxygen transport, and finally central nervous system disorders. We recommend powered air respirators with ABEK+P3 cartridges and carbon monoxide gas detectors as the minimum requirement for those working inside biomass-fired power plant boilers, and compressed air breathing apparatus as the best form of protection. Copyright © 2012 Elsevier Ltd. All rights reserved.

Retrospective dose assessment for the population living in areas of local fallout from the Semipalatinsk nuclear test site Part I: External exposure.

PubMed

Gordeev, Konstantin; Shinkarev, Sergey; Ilyin, Leonid; Bouville, André; Hoshi, Masaharu; Luckyanov, Nickolas; Simon, Steven L

2006-02-01

A short analysis of all 111 atmospheric events conducted at the Semipalatinsk Test Site (STS) in 1949-1962 with regard to significant off-site exposure (more than 5 mSv of the effective dose during the first year after the explosion) has been made. The analytical method used to assess external exposure to the residents living in settlements near the STS is described. This method makes use of the archival data on the radiological conditions, including the measurements of exposure rate. Special attention was given to the residents of Dolon and Kanonerka villages exposed mainly as a result of the first test, detonated on August 29, 1949. For the residents of those settlements born in 1935, the dose estimates calculated according to the analytical method, are compared to those derived from the thermoluminescence measurements in bricks and electron paramagnetic resonance measurements in teeth. The methods described in this paper were used for external dose assessment for the cohort members at an initial stage of an ongoing epidemiological study conducted by the U.S. National Cancer Institute in the Republic of Kazakhstan. Recently revised methods and estimates of external exposure for that cohort are given in another paper (Simon et al.) in this conference.

Alcohol as a risk factor for injuries or death due to fires and burns: review of the literature.

PubMed Central

Howland, J; Hingson, R

1987-01-01

The findings in 32 studies on alcohol and injuries and deaths attributed to fires and burns were analyzed in detail. The studies, all in English, were published between 1947 and 1986. Most of them were descriptive and reported on the percent of the victims who were exposed to alcohol. Eight of the nine best descriptive studies indicated that alcohol exposure was more likely among those who died in fires ignited by cigarettes than those attributable to other causes. It can be concluded that there is substantial, although not definitive, evidence that alcohol plays a role in the etiology of fire and burn injuries and deaths. PMID:3116577

Estimated Global Mortality Attributable to Smoke from Landscape Fires

PubMed Central

Henderson, Sarah B.; Chen, Yang; Randerson, James T.; Marlier, Miriam; DeFries, Ruth S.; Kinney, Patrick; Bowman, David M.J.S.; Brauer, Michael

2012-01-01

Background: Forest, grass, and peat fires release approximately 2 petagrams of carbon into the atmosphere each year, influencing weather, climate, and air quality. Objective: We estimated the annual global mortality attributable to landscape fire smoke (LFS). Methods: Daily and annual exposure to particulate matter ≤ 2.5 μm in aerodynamic diameter (PM2.5) from fire emissions was estimated globally for 1997 through 2006 by combining outputs from a chemical transport model with satellite-based observations of aerosol optical depth. In World Health Organization (WHO) subregions classified as sporadically affected, the daily burden of mortality was estimated using previously published concentration–response coefficients for the association between short-term elevations in PM2.5 from LFS (contrasted with 0 μg/m3 from LFS) and all-cause mortality. In subregions classified as chronically affected, the annual burden of mortality was estimated using the American Cancer Society study coefficient for the association between long-term PM2.5 exposure and all-cause mortality. The annual average PM2.5 estimates were contrasted with theoretical minimum (counterfactual) concentrations in each chronically affected subregion. Sensitivity of mortality estimates to different exposure assessments, counterfactual estimates, and concentration–response functions was evaluated. Strong La Niña and El Niño years were compared to assess the influence of interannual climatic variability. Results: Our principal estimate for the average mortality attributable to LFS exposure was 339,000 deaths annually. In sensitivity analyses the interquartile range of all tested estimates was 260,000–600,000. The regions most affected were sub-Saharan Africa (157,000) and Southeast Asia (110,000). Estimated annual mortality during La Niña was 262,000, compared with 532,000 during El Niño. Conclusions: Fire emissions are an important contributor to global mortality. Adverse health outcomes associated with LFS could be substantially reduced by curtailing burning of tropical rainforests, which rarely burn naturally. The large estimated influence of El Niño suggests a relationship between climate and the burden of mortality attributable to LFS. PMID:22456494

The effect of exposure to missile attacks on posttraumatic stress disorder symptoms as a function of perceived media control and locus of control.

PubMed

Hoffman, Yaakov S G; Shrira, Amit; Cohen-Fridel, Sara; Grossman, Ephraim S; Bodner, Ehud

2016-10-30

Exposure is one of the most robust predictors of post-traumatic stress disorder (PTSD) symptoms in warfare situations. Yet, while many are sensitive to exposure, others do not develop PTSD. In the current study, we address how perceived media control along with external locus of control moderate effects of exposure on PTSD symptoms among 1268 individuals exposed to missile attacks (mean age=36.97). We expected that the coupling of low perceived media control, whereby one feels poor control over media consumption (an inability to stop), especially when irrelevant and non-informative (e.g., involuntarily viewing the same terror incident shown repeatedly in a looped fashion) along with a self-perception of external locus of control, will render participants highly vulnerable to exposure. As expected, results suggest that effects of exposure on PTSD are not automatic, rather, the coupling of both low media control along with believing that life event are controlled by external factors exacerbates effects of exposure. These findings bear practical implications, as both media control and locus of control can be modified by therapeutic interventions, rendering one less vulnerable to the detrimental effects of traumatic exposure. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Roadside fire prevention signs --- standard and new designs compared

Treesearch

Gail J. Ruckel; William S. Folkman

1966-01-01

The impact and recall value of a set of regularly used U.S. Forest Service fire prevention signs were compared with that of a set of improvised signs by interviews with typical forest users. The improvised signs generated a substantially greater impact. Although the regular signs have had past exposure to the general public, they demonstrated no significant difference...

30 CFR 75.1321 - Permits for firing more than 20 boreholes and for use of nonpermissible blasting units.

Code of Federal Regulations, 2011 CFR

2011-07-01

... approximate number of boreholes to be fired; (3) The period of time during which the permit will apply; (4..., track grading, roof brushing or boom holes; (5) A plan, proposed by the operator designed to protect... scaling and supporting the remaining roof prior to wiring a new series of boreholes; (2) Exposure to...

30 CFR 75.1321 - Permits for firing more than 20 boreholes and for use of nonpermissible blasting units.

Code of Federal Regulations, 2013 CFR

2013-07-01

... approximate number of boreholes to be fired; (3) The period of time during which the permit will apply; (4..., track grading, roof brushing or boom holes; (5) A plan, proposed by the operator designed to protect... scaling and supporting the remaining roof prior to wiring a new series of boreholes; (2) Exposure to...

30 CFR 75.1321 - Permits for firing more than 20 boreholes and for use of nonpermissible blasting units.

Code of Federal Regulations, 2010 CFR

2010-07-01

... approximate number of boreholes to be fired; (3) The period of time during which the permit will apply; (4..., track grading, roof brushing or boom holes; (5) A plan, proposed by the operator designed to protect... scaling and supporting the remaining roof prior to wiring a new series of boreholes; (2) Exposure to...

30 CFR 75.1321 - Permits for firing more than 20 boreholes and for use of nonpermissible blasting units.

Code of Federal Regulations, 2012 CFR

2012-07-01

... approximate number of boreholes to be fired; (3) The period of time during which the permit will apply; (4..., track grading, roof brushing or boom holes; (5) A plan, proposed by the operator designed to protect... scaling and supporting the remaining roof prior to wiring a new series of boreholes; (2) Exposure to...

Survival of northern red oak acorns after fall burning

Treesearch

L.R. Auchmoody; H. Clay Smith; H. Clay Smith

1993-01-01

Survival of recently fallen northern red oak acorns after exposure to a cool fall burn was evaluated in northwestern Pennsylvania. Although no acorns were consumed by the fire, some were charred. Between 40 and 49 percent of the acorns in the litter were destroyed. The fire was not hot enough to kill Curculio larvae within the acorns. Burned acorns infested with...

Forest worker exposure to airborne herbicide residues in smoke from prescribed fires in the Southern United States

Treesearch

Charles K. McMahon; Parshall B. Bush

1992-01-01

Occupational safety and health concerns have been raised in a number of southern states by workers conducting prescribed burns on forested lands treated with herbicides. Modeling assessments coupled with laboratory experiments have shown that the risk of airborne herbicide residues to workers is insignificant, even if the fire occurs immediately after herbicide...

Utility of remotely sensed imagery for assessing the impact of salvage logging after forest fires

Treesearch

Sarah A. Lewis; Peter R. Robichaud; Andrew T. Hudak; Brian Austin; Robert J. Liebermann

2012-01-01

Remotely sensed imagery provides a useful tool for land managers to assess the extent and severity of post-wildfire salvage logging disturbance. This investigation uses high resolution QuickBird and National Agricultural Imagery Program (NAIP) imagery to map soil exposure after ground-based salvage operations. Three wildfires with varying post-fire salvage activities...

Effects of wildfire on sea otter (Enhydra lutris) gene transcript profiles

USGS Publications Warehouse

Bowen, Lizabeth; Miles, A. Keith; Kolden, Crystal A.; Saarinen, Justin A.; Bodkin, James L.; Murray, Michael J.; Tinker, M. Tim

2015-01-01

Wildfires have been shown to impact terrestrial species over a range of temporal scales. Little is known, however, about the more subtle toxicological effects of wildfires, particularly in downstream marine or downwind locations from the wildfire perimeter. These down-current effects may be just as substantial as those effects within the perimeter. We used gene transcription technology, a sensitive indicator of immunological perturbation, to study the effects of the 2008 Basin Complex Fire on the California coast on a sentinel marine species, the sea otter (Enhydra lutris). We captured sea otters in 2008 (3 mo after the Basin Complex Fire was controlled) and 2009 (15 mo after the Basin Complex Fire was controlled) in the adjacent nearshore environment near Big Sur, California. Gene responses were distinctly different between Big Sur temporal groups, signifying detoxification of PAHs, possible associated response to potential malignant transformation, and suppression of immune function as the primary responses of sea otters to fire in 2008 compared to those captured in 2009. In general, gene transcription patterns in the 2008 sea otters were indicative of molecular reactions to organic exposure, malignant transformation, and decreased ability to respond to pathogens that seemed to consistent with short-term hydrocarbon exposure.

Properties of concrete containing different type of waste materials as aggregate replacement exposed to elevated temperature – A review

NASA Astrophysics Data System (ADS)

Ghadzali, N. S.; Ibrahim, M. H. W.; Sani, M. S. H. Mohd; Jamaludin, N.; Desa, M. S. M.; Misri, Z.

2018-04-01

Concrete is the chief material of construction and it is non-combustible in nature. However, the exposure to the high temperature such as fire can lead to change in the concrete properties. Due to the higher temperature, several changes in terms of mechanical properties were observed in concrete such as compressive strength, modulus of elasticity, tensile strength and durability of concrete will decrease significantly at high temperature. The exceptional fire-proof achievement of concrete is might be due to the constituent materials of concrete such as its aggregates. The extensive use of aggregate in concrete will leads to depletion of natural resources. Hence, the use of waste and other recycled and by-product material as aggregates replacements becomes a leading research. This review has been made on the utilization of waste materials in concrete and critically evaluates its effects on the concrete performances during the fire exposure. Therefore, the objective of this paper is to review the previous search work regarding the concrete containing waste material as aggregates replacement when exposed to elevated temperature and come up with different design recommendations to improve the fire resistance of structures.

Chemical speciation of trace metals emitted from Indonesian peat fires for health risk assessment

NASA Astrophysics Data System (ADS)

Betha, Raghu; Pradani, Maharani; Lestari, Puji; Joshi, Umid Man; Reid, Jeffrey S.; Balasubramanian, Rajasekhar

2013-03-01

Regional smoke-induced haze in Southeast Asia, caused by uncontrolled forest and peat fires in Indonesia, is of major environmental and health concern. In this study, we estimated carcinogenic and non-carcinogenic health risk due to exposure to fine particles (PM2.5) as emitted from peat fires at Kalimantan, Indonesia. For the health risk analysis, chemical speciation (exchangeable, reducible, oxidizable, and residual fractions) of 12 trace metals (Al, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Ti, V and Zn) in PM2.5 was studied. Results indicate that Al, Fe and Ti together accounted for a major fraction of total metal concentrations (~ 83%) in PM2.5 emissions in the immediate vicinity of peat fires. Chemical speciation reveals that a major proportion of most of the metals, with the exception of Cr, Mn, Fe, Ni and Cd, was present in the residual fraction. The exchangeable fraction of metals, which represents their bioavailability, could play a major role in inducing human health effects of PM2.5. This fraction contained carcinogenic metals such as Cd (39.2 ng m- 3) and Ni (249.3 ng m- 3) that exceeded their WHO guideline values by several factors. Health risk estimates suggest that exposure to PM2.5 emissions in the vicinity of peat fires poses serious health threats.

Exposure to radionuclides in smoke from vegetation fires.

PubMed

Carvalho, Fernando P; Oliveira, João M; Malta, Margarida

2014-02-15

Naturally occurring radionuclides of uranium, thorium, radium, lead and polonium were determined in bushes and trees and in the smoke from summer forest fires. Activity concentrations of radionuclides in smoke particles were much enriched when compared to original vegetation. Polonium-210 ((210)Po) in smoke was measured in concentrations much higher than all other radionuclides, reaching 7,255 ± 285 Bq kg(-1), mostly associated with the smaller size smoke particles (<1.0 μm). Depending on smoke particle concentration, (210)Po in surface air near forest fires displayed volume concentrations up to 70 m Bq m(-3), while in smoke-free air (210)Po concentration was about 30 μ Bq m(-3). The estimated absorbed radiation dose to an adult member of the public or a firefighter exposed for 24h to inhalation of smoke near forest fires could exceed 5 μSv per day, i.e, more than 2000 times above the radiation dose from background radioactivity in surface air, and also higher than the radiation dose from (210)Po inhalation in a chronic cigarette smoker. It is concluded that prolonged exposure to smoke allows for enhanced inhalation of radionuclides associated with smoke particles. Due to high radiotoxicity of alpha emitting radionuclides, and in particular of (210)Po, the protection of respiratory tract of fire fighters is strongly recommended. Copyright © 2013 Elsevier B.V. All rights reserved.

10 CFR 835.203 - Combining internal and external equivalent doses.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Combining internal and external equivalent doses. 835.203 Section 835.203 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.203 Combining internal and external equivalent doses. (a) The total effective dose...

Network-induced chaos in integrate-and-fire neuronal ensembles.

PubMed

Zhou, Douglas; Rangan, Aaditya V; Sun, Yi; Cai, David

2009-09-01

It has been shown that a single standard linear integrate-and-fire (IF) neuron under a general time-dependent stimulus cannot possess chaotic dynamics despite the firing-reset discontinuity. Here we address the issue of whether conductance-based, pulsed-coupled network interactions can induce chaos in an IF neuronal ensemble. Using numerical methods, we demonstrate that all-to-all, homogeneously pulse-coupled IF neuronal networks can indeed give rise to chaotic dynamics under an external periodic current drive. We also provide a precise characterization of the largest Lyapunov exponent for these high dimensional nonsmooth dynamical systems. In addition, we present a stable and accurate numerical algorithm for evaluating the largest Lyapunov exponent, which can overcome difficulties encountered by traditional methods for these nonsmooth dynamical systems with degeneracy induced by, e.g., refractoriness of neurons.

Behavior of Insulated Carbon-FRP-Strengthened RC Beams Exposed to Fire

NASA Astrophysics Data System (ADS)

Sayin, B.

2014-09-01

There are two main approaches to improving the fire resistance of fiber-reinforced polymer (FRP) systems. While the most common method is to protect or insulate the FRP system, an other way is to use fibers and resins with a better fire performance. This paper presents a numerical investigation into the five protection behavior of insulated carbon-fiber-reinforced-polymer (CFRP)-strengthened reinforced concrete (RC) beams. The effects of external loading and thermal expansion of materials at elevated temperatures are taken into consideration in a finite-element model. The validity of the numerical model is demonstrated with results from an existing experimental study on insulated CFRP-strengthened RC beams. Conclusions of this investigation are employed to predict the structural behavior of CFRP-strengthened concrete structures.

Localized Ignition And Subsequent Flame Spread Over Solid Fuels In Microgravity

NASA Technical Reports Server (NTRS)

Kashiwagi, T.; Nakamura, Y.; Prasad, K.; Baum, H.; Olson, S.; Fujita, O.; Nishizawa, K.; Ito, K.

2003-01-01

Localized ignition is initiated by an external radiant source at the middle of a thin solid sheet under external slow flow, simulating fire initiation in a spacecraft with a slow ventilation flow. Ignition behavior, subsequent transition simultaneously to upstream and downstream flame spread, and flame growth behavior are studied theoretically and experimentally. There are two transition stages in this study; one is the first transition from the onset of the ignition to form an initial anchored flame close to the sample surface, near the ignited area. The second transition is the flame growth stage from the anchored flame to a steady fire spread state (i.e. no change in flame size or in heat release rate) or a quasi-steady state, if either exists. Observations of experimental spot ignition characteristics and of the second transition over a thermally thin paper were made to determine the effects of external flow velocity. Both transitions have been studied theoretically to determine the effects of the confinement by a relatively small test chamber, of the ignition configuration (ignition across the sample width vs spot ignition), and of the external flow velocity on the two transitions over a thermally thin paper. This study is currently extending to two new areas; one is to include a thermoplastic sample such poly(methymethacrylate), PMMA, and the other is to determine the effects of sample thickness on the transitions. The recent results of these new studies on the first transition are briefly reported.

Internal exposure from building materials exhaling (222)Rn and (220)Rn as compared to external exposure due to their natural radioactivity content.

PubMed

Ujić, Predrag; Celiković, Igor; Kandić, Aleksandar; Vukanac, Ivana; Durasević, Mirjana; Dragosavac, Dusan; Zunić, Zora S

2010-01-01

The main scope of this paper is to point out the importance of introducing radon and thoron exhalation measurements from building materials in the regulating frame. Currently (2009), such a regulation of this kind of exposure is not explicitly included in the Serbian regulating network. To this end, this work reports concentration measurements of (226)Ra, (232)Th and (40)K and radon and thoron exhalation rates from building materials used in Serbia. Following detailed analysis, it was noticed that both internal exposures to radon and/or thoron exhaling from building materials may exceed external exposures to their precursors contained therein.

Urban fire risk control: House design, upgrading and replanning

PubMed Central

Mbuya, Elinorata Celestine

2018-01-01

Urbanisation leads to house densification, a phenomenon experienced in both planned and unplanned settlements in cities in developing countries. Such densification limits fire brigade access into settlements, thereby aggravating fire disaster risks. In this article, we assess the fire exposure and risks in residences in informal areas of Mchikichini ward, in Dar es Salaam City, Tanzania. We rely on interviews of residents and government officials to obtain background on the occurrence and causes of fire accidents, policy provisions and regulations, and experiences with fire outbreaks and coping strategies, as well as on observations and measurements of house transformations, spatial quality and indoor real life. Our findings suggest that fire risks arise from both inappropriate structural characteristics and unsound behavioural practices. This includes unsafe electric practices by residents, poor capacity of residents to fight fires once started, limited access to structures by firefighting equipment because of flouting of planning regulations and inadequate awareness of local government leaders of the magnitude of fire risks. Potential changes to reduce fire risks in the settlement include the installation of firefighting systems, restriction of cooking to designated spaces, use of safer cooking energy sources and lighting means, improvements of vehicle access routes to neighbourhoods, capacity building at the grass root level and the establishment of community-based fire risk management.

Environmental externalities: Thinking globally, taxing locally

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

Trisko, E.M.

1993-03-01

Assigning monetary externality values to the airborne emissions of electric power plants is gaining the attention of state utility commissions as a means to measure the social costs of alternative energy investments. Some commissions are using environmental externalities to encourage utility investments in energy conservation and renewable energy technologies such as solar, wind, and biomass. However, the monetization of externalities through so-called adders to direct generation costs can lead to inefficient resource allocation and expose consumers to electric rate increases without corresponding environmental benefits. The addition of externality values to direct electric generation costs distorts the economics of power supplymore » planning by creating artificial subsidies for generation sources that are not currently competitive in the market. Businesses and consumers will be forced to support higher-cost sources of electric generation as a consequence. Because pollutant emissions of all new sources of electric generation are stringently regulated, and generally are well below those of existing fossil-fired sources, little demonstrable environmental benefit would result from the expanded use of externality valuation.« less

External Ballistics. Part 2

DTIC Science & Technology

1978-07-11

ucaymaetrically. Page £98. is a result cf the elastic iroperties cf rccket, of launcher and scil , the initial conditicns of moving the rocket differ from...instrument depends or. many factors: the elastic Fropesties of shaft and gur carriaSe, scil cf the firing position, tallistics of instrument, which

Heat Effects on Living Plants

Treesearch

Robert C. Hare

1961-01-01

This review of knowledge concerning the effects of high temperatures on plants was undertaken in preparation for research aimed at determining how forest fires affect physiological processes in woody species. Major subjects discussed include morphological and physiological responses to high temperatures, external and internal factors governing these responses,...

Analysis of Neuronal Spike Trains, Deconstructed

PubMed Central

Aljadeff, Johnatan; Lansdell, Benjamin J.; Fairhall, Adrienne L.; Kleinfeld, David

2016-01-01

As information flows through the brain, neuronal firing progresses from encoding the world as sensed by the animal to driving the motor output of subsequent behavior. One of the more tractable goals of quantitative neuroscience is to develop predictive models that relate the sensory or motor streams with neuronal firing. Here we review and contrast analytical tools used to accomplish this task. We focus on classes of models in which the external variable is compared with one or more feature vectors to extract a low-dimensional representation, the history of spiking and other variables are potentially incorporated, and these factors are nonlinearly transformed to predict the occurrences of spikes. We illustrate these techniques in application to datasets of different degrees of complexity. In particular, we address the fitting of models in the presence of strong correlations in the external variable, as occurs in natural sensory stimuli and in movement. Spectral correlation between predicted and measured spike trains is introduced to contrast the relative success of different methods. PMID:27477016

Behaviour of fibre reinforced polymer confined reinforced concrete columns under fire condition

NASA Astrophysics Data System (ADS)

Chowdhury, Ershad Ullah

In recent years, fibre reinforced polymer (FRP) materials have demonstrated enormous potential as materials for repairing and retrofitting concrete bridges that have deteriorated from factors such as electro-chemical corrosion and increased load requirements. However, concerns associated with fire remain an obstacle to applications of FRP materials in buildings and parking garages due to FRP's sensitivity to high temperatures as compared with other structural materials and to limited knowledge on their thermal and mechanical behaviour in fire. This thesis presents results from an ongoing study on the fire performance of FRP materials, fire insulation materials and systems, and FRP wrapped reinforced concrete columns. The overall goal of the study is to understand the fire behaviour of FRP materials and FRP strengthened concrete columns and ultimately, provide rational fire safety design recommendations and guidelines for FRP strengthened concrete columns. A combined experimental and numerical investigation was conducted to achieve the goals of this research study. The experimental work consisted of both small-scale FRP material testing at elevated temperatures and full-scale fire tests on FRP strengthened columns. A numerical model was developed to simulate the behaviour of unwrapped reinforced concrete and FRP strengthened reinforced concrete square or rectangular columns in fire. After validating the numerical model against test data available in literature, it was determined that the numerical model can be used to analyze the behaviour of concrete axial compressive members in fire. Results from this study also demonstrated that although FRP materials experience considerable loss of their mechanical and bond properties at temperatures somewhat below the glass transition temperature of the resin matrix, externally-bonded FRP can be used in strengthening concrete structural members in buildings, if appropriate supplemental fire protection system is provided over the FRP strengthening system.

Fire, Fuel Composition and Resilience Threshold in Subalpine Ecosystem

PubMed Central

Blarquez, Olivier; Carcaillet, Christopher

2010-01-01

Background Forecasting the effects of global changes on high altitude ecosystems requires an understanding of the long-term relationships between biota and forcing factors to identify resilience thresholds. Fire is a crucial forcing factor: both fuel build-up from land-abandonment in European mountains, and more droughts linked to global warming are likely to increase fire risks. Methods To assess the vegetation response to fire on a millennium time-scale, we analyzed evidence of stand-to-local vegetation dynamics derived from sedimentary plant macroremains from two subalpine lakes. Paleobotanical reconstructions at high temporal resolution, together with a fire frequency reconstruction inferred from sedimentary charcoal, were analyzed by Superposed Epoch Analysis to model plant behavior before, during and after fire events. Principal Findings We show that fuel build-up from arolla pine (Pinus cembra) always precedes fires, which is immediately followed by a rapid increase of birch (Betula sp.), then by ericaceous species after 25–75 years, and by herbs after 50–100 years. European larch (Larix decidua), which is the natural co-dominant species of subalpine forests with Pinus cembra, is not sensitive to fire, while the abundance of Pinus cembra is altered within a 150-year period after fires. A long-term trend in vegetation dynamics is apparent, wherein species that abound later in succession are the functional drivers, loading the environment with fuel for fires. This system can only be functional if fires are mainly driven by external factors (e.g. climate), with the mean interval between fires being longer than the minimum time required to reach the late successional stage, here 150 years. Conclusion Current global warming conditions which increase drought occurrences, combined with the abandonment of land in European mountain areas, creates ideal ecological conditions for the ignition and the spread of fire. A fire return interval of less than 150 years would threaten the dominant species and might override the resilience of subalpine forests. PMID:20814580

Noise Enhances Action Potential Generation in Mouse Sensory Neurons via Stochastic Resonance.

PubMed

Onorato, Irene; D'Alessandro, Giuseppina; Di Castro, Maria Amalia; Renzi, Massimiliano; Dobrowolny, Gabriella; Musarò, Antonio; Salvetti, Marco; Limatola, Cristina; Crisanti, Andrea; Grassi, Francesca

2016-01-01

Noise can enhance perception of tactile and proprioceptive stimuli by stochastic resonance processes. However, the mechanisms underlying this general phenomenon remain to be characterized. Here we studied how externally applied noise influences action potential firing in mouse primary sensory neurons of dorsal root ganglia, modelling a basic process in sensory perception. Since noisy mechanical stimuli may cause stochastic fluctuations in receptor potential, we examined the effects of sub-threshold depolarizing current steps with superimposed random fluctuations. We performed whole cell patch clamp recordings in cultured neurons of mouse dorsal root ganglia. Noise was added either before and during the step, or during the depolarizing step only, to focus onto the specific effects of external noise on action potential generation. In both cases, step + noise stimuli triggered significantly more action potentials than steps alone. The normalized power norm had a clear peak at intermediate noise levels, demonstrating that the phenomenon is driven by stochastic resonance. Spikes evoked in step + noise trials occur earlier and show faster rise time as compared to the occasional ones elicited by steps alone. These data suggest that external noise enhances, via stochastic resonance, the recruitment of transient voltage-gated Na channels, responsible for action potential firing in response to rapid step-wise depolarizing currents.

Noise Enhances Action Potential Generation in Mouse Sensory Neurons via Stochastic Resonance

PubMed Central

Onorato, Irene; D'Alessandro, Giuseppina; Di Castro, Maria Amalia; Renzi, Massimiliano; Dobrowolny, Gabriella; Musarò, Antonio; Salvetti, Marco; Limatola, Cristina; Crisanti, Andrea; Grassi, Francesca

2016-01-01

Noise can enhance perception of tactile and proprioceptive stimuli by stochastic resonance processes. However, the mechanisms underlying this general phenomenon remain to be characterized. Here we studied how externally applied noise influences action potential firing in mouse primary sensory neurons of dorsal root ganglia, modelling a basic process in sensory perception. Since noisy mechanical stimuli may cause stochastic fluctuations in receptor potential, we examined the effects of sub-threshold depolarizing current steps with superimposed random fluctuations. We performed whole cell patch clamp recordings in cultured neurons of mouse dorsal root ganglia. Noise was added either before and during the step, or during the depolarizing step only, to focus onto the specific effects of external noise on action potential generation. In both cases, step + noise stimuli triggered significantly more action potentials than steps alone. The normalized power norm had a clear peak at intermediate noise levels, demonstrating that the phenomenon is driven by stochastic resonance. Spikes evoked in step + noise trials occur earlier and show faster rise time as compared to the occasional ones elicited by steps alone. These data suggest that external noise enhances, via stochastic resonance, the recruitment of transient voltage-gated Na channels, responsible for action potential firing in response to rapid step-wise depolarizing currents. PMID:27525414

Toxic smoke inhalation in fire victim dogs.

PubMed

Stern, A W; Lewis, R J; Thompson, K S

2014-11-01

Fifteen dogs were found dead in a house that was on fire. Several of these dogs were partially burned. Four dogs were submitted for postmortem examination, 2 of which were determined to have died prior to the fire. Of the 2 submitted fire fatalities, only 1 dog had burns on its body (dorsum and right side of body). Internally, both dogs had soot deposits mixed with mucus in the larynx, trachea, and primary bronchi. Microscopically, soot was identified within both airways and alveolar spaces. There were no macroscopic or microscopic indications of vital heat exposure. High levels of carboxyhemoglobin were detected in the 2 dogs tested. The findings in this case support the use of postmortem examination and toxicology testing to allow for determination of vital reaction to heat and fire fumes. © The Author(s) 2014.

An assessment of the radiological impact of the Windscale reactor fire, October 1957.

PubMed

Crick, M J; Linsley, G S

1984-11-01

On the 10th and 11 October 1957 a fire in the No 1 Pile at the Windscale establishment in Cumbria led to an uncontrolled release of activity to the atmosphere. The resultant cloud subsequently dispersed and radionuclides could be detected over England, Wales and parts of northern Europe. The extensive environmental measurements which were made during and after the release enabled a fairly accurate estimate to be made of the radiation doses to the most exposed individuals in the local population. Until recently, no estimates of the population dose resulting from the release had been published. This paper describes assessments which have been made by the NRPB of the population or collective dose from the release and of the possible associated health impact. In addition to the fission products that escaped, radionuclides were released from materials undergoing irradiation in the pile at the time of the fire. The assessment has included the results of a review of previously unpublished data which established the quantity of these nuclides released and considers their impact on both individual and population doses. The collective effective dose equivalent commitment from the release is estimated to have been 2.0 x 10(3) man Sv. The route of exposure which contributed the most to the collective dose was the inhalation pathway. Iodine-131 was the most important radionuclide, contributing nearly all of the collective dose to the thyroid and a large part of the collective effective dose. Polonium-210 and caesium-137 also made significant contributions; that from caesium-137 came in the longer term via external irradiation from ground deposits and the ingestion of contaminated foodstuffs. The methodology used in the study has been validated to a certain degree by comparing the predicted levels of individual thyroid activity and those measured directly in the weeks following the accident in London, Leeds and Cumbria.

Leukemia risk associated with chronic external exposure to ionizing radiation in a French cohort of nuclear workers.

PubMed

Metz-Flamant, C; Samson, E; Caër-Lorho, S; Acker, A; Laurier, D

2012-11-01

Leukemia is one of the earliest cancer effects observed after acute exposure to relatively high doses of ionizing radiation. Leukemia mortality after external exposure at low doses and low-dose rates has been investigated at the French Atomic Energy Commission (CEA) and Nuclear Fuel Company (AREVA NC) after an additional follow-up of 10 years. The cohort included radiation-monitored workers employed for at least one year during 1950-1994 at CEA or AREVA NC and followed during 1968-2004. Association between external exposure and leukemia mortality was estimated with excess relative risk (ERR) models and time-dependent modifying factors were investigated with time windows. The cohort included 36,769 workers, followed for an average of 28 years, among whom 73 leukemia deaths occurred. Among the workers with a positive recorded dose, the mean cumulative external dose was 21.7 mSv. Results under a 2-year lag assumption suggested that the risk of leukemia (except chronic lymphatic leukemia) increased significantly by 8% per 10 mSv. The magnitude of the association for myeloid leukemia was larger. The higher ERR/Sv for doses received 2-14 years earlier suggest that time since exposure modifies the effect. The ERR/Sv also appeared higher for doses received at exposure rates ≥20 mSv per year. These results are consistent with those found in other studies of nuclear workers. However, confidence intervals are still wide. Further analyses should be conducted in pooled cohorts of nuclear workers.

Health hazard evaluation report HETA 98-0152-2729, Wolfeboro Public Safety Building, Wolfeboro, New Hampshire

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

Sylvain, D.; Echt, A.

On March 17, 1998, the National Institute for Occupational Safety and Health (NIOSH) received a Health Hazard Evaluation request (HHE) from the New Hampshire Department of Labor to conduct an evaluation of diesel exhaust exposure at the Wolfeboro Public Safety Building, in Wolfeboro, New Hampshire. The request indicated that Fire and Police personnel were exposed to diesel exhaust from fire apparatus. Asthmatic bronchitis was listed as a health problem resulting from this exposure. On June 23, 1998, NIOSH investigators, accompanied by an industrial hygienist from the New Hampshire Bureau of Health Risk Assessment, conducted an industrial hygiene evaluation at themore » Wolfeboro Public Safety Building.« less

Study of toxicological evaluation of fire suppressants and extinguishers

NASA Technical Reports Server (NTRS)

1975-01-01

The application of fluorocarbons as possible candidates for fire extinguishers and/or suppressants in confined spaces (such as spacecraft, aircraft, or submarines) was investigated, with special emphasis on their safety to man since they would be inhaled on an almost continuous basis. Short-term exposure experiments, using various animal species, were devised to look at specific parameters in order to determine which of the candidate compounds were sufficiently non-toxic to warrant long-term investigations. The following physiologic criteria were examined; tissue distribution, fluoride concentration, effect on mitochondria, microsomes, liposomes, and liver cell nuclei, erythrocyte fragility, clinical chemistry values, hematology, pathology, cardiac sensitization, behavioral effects. Various rodent species were used for initial investigations, with non-human primate exposures for Freon 116 which was warranted for negative results on rodents. Various types of exposure chambers were used, including closed dynamic chambers allowing for a recirculating atmosphere.

Heat and Moisture Transport and Storage Parameters of Bricks Affected by the Environment

NASA Astrophysics Data System (ADS)

Kočí, Václav; Čáchová, Monika; Koňáková, Dana; Vejmelková, Eva; Jerman, Miloš; Keppert, Martin; Maděra, Jiří; Černý, Robert

2018-05-01

The effect of external environment on heat and moisture transport and storage properties of the traditional fired clay brick, sand-lime brick and highly perforated ceramic block commonly used in the Czech Republic and on their hygrothermal performance in building envelopes is analyzed by a combination of experimental and computational techniques. The experimental measurements of thermal, hygric and basic physical parameters are carried out in the reference state and after a 3-year exposure of the bricks to real climatic conditions of the city of Prague. The obtained results showed that after 3 years of weathering the porosity of the analyzed bricks increased up to five percentage points which led to an increase in liquid and gaseous moisture transport parameters and a decrease in thermal conductivity. Computational modeling of hygrothermal performance of building envelopes made of the studied bricks was done using both reference and weather-affected data. The simulated results indicated an improvement in the annual energy balances and a decrease in the time-of-wetness functions as a result of the use of data obtained after the 3-year exposure to the environment. The effects of weathering on both heat and moisture transport and storage parameters of the analyzed bricks and on their hygrothermal performance were found significant despite the occurrence of warm winters in the time period of 2012-2015 when the brick specimens were exposed to the environment.

Experimental Forecasts of Wildfire Pollution at the Canadian Meteorological Centre

NASA Astrophysics Data System (ADS)

Pavlovic, Radenko; Beaulieu, Paul-Andre; Chen, Jack; Landry, Hugo; Cousineau, Sophie; Moran, Michael

2016-04-01

Environment and Climate Change Canada's Canadian Meteorological Centre Operations division (CMCO) has been running an experimental North American air quality forecast system with near-real-time wildfire emissions since 2014. This system, named FireWork, also takes anthropogenic and other natural emission sources into account. FireWork 48-hour forecasts are provided to CMCO forecasters and external partners in Canada and the U.S. twice daily during the wildfire season. This system has proven to be very useful in capturing short- and long-range smoke transport from wildfires over North America. Several upgrades to the FireWork system have been made since 2014 to accommodate the needs of operational AQ forecasters and to improve system performance. In this talk we will present performance statistics and some case studies for the 2014 and 2015 wildfire seasons. We will also describe current limitations of the FireWork system and ongoing and future work planned for this air quality forecast system.

The acute toxicity of brief exposures to HF, HCl, NO2 and HCN singly and in combination with CO.

DOT National Transportation Integrated Search

1971-11-01

Experiments were conducted with animals to determine the toxic effect of short-term exposures to some of the products produced in aircraft fires; the products were tested both singly and in combination with carbon monoxide. These studies show the tox...

Smoke Sense Demonstration at National Academies of Science Citizen Science Expo

EPA Science Inventory

Exposure to wildland fire smoke can be sudden and unexpected, last hours to weeks, and affect communities that may or may not have a public health response plan to reduce the adverse impacts of smoke exposure. EPA is continuing to advance the science and technology required to u...

Characteristics of low IQ arsonists at psychiatric assessment.

PubMed

Dickens, Geoff; Sugarman, Philip; Ahmad, Farooq; Edgar, Simon; Hofberg, Kristina; Tewari, Sidharta

2008-07-01

We conducted a retrospective study of arsonists referred for psychiatric assessment and found that 88/202 (43.6%) had an IQ of 85 or below. The low IQ group showed more evidence of childhood temperamental disturbance, and a later pattern of internal problems rather than external factors expressing themselves as fire-setting. This study highlights the likelihood of lifelong, temperamental problems being apparent in childhood, and being predictive and possibly causative of fire setting in people with a low IQ. Better understanding of the distinct characteristics of lower IQ arsonists is essential for improved prevention, treatment and management.

Evaluation of external hazards to nuclear power plants in the United States

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

Kimura, C.Y.; Budnitz, R.J.

1987-12-01

The Lawrence Livermore National Laboratory (LLNL) has performed a study of the risk of core damage to nuclear power plants in the United States due to externally initiated events. The broad objective has been to gain an understanding of whether or not each external initiator is among the major potential accident initiators that may pose a threat of severe reactor core damage or of large radioactive release to the environment from the reactor. Four external hazards were investigated in this report. These external hazards are internal fires, high winds/tornadoes, external floods, and transportation accidents. Analysis was based on two figures-of-merit,more » one based on core damage frequency and the other based on the frequency of large radioactive releases. Using these two figures-of-merit as evaluation criteria, it has been feasible to ascertain whether the risk from externally initiated accidents is, or is not, an important contributor to overall risk for the US nuclear power plants studied. This has been accomplished for each initiator separately. 208 refs., 17 figs., 45 tabs.« less

33 CFR 155.4025 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... another, when the vessel's own transfer equipment is not working. External firefighting teams means... vessel, or damage to the marine environment. Marine firefighting pre-fire plan means a plan that outlines... scene, at a safe distance from the vessel or on the vessel, who can determine the steps needed to...

Piloted Ignition to Flaming in Smoldering Fire-Retarded Polyurethane Foam

NASA Technical Reports Server (NTRS)

Putzeys, O.; Fernandez-Pello, A. C.; Urban, D. L.

2007-01-01

Experimental results are presented on the piloted transition from smoldering to flaming in the fire-retarded polyurethane foam Pyrell . The samples are small rectangular blocks with a square cross section, vertically placed in the wall of a vertical wind tunnel. Three of the vertical sample sides are insulated and the fourth side is exposed to an upward oxidizer flow of variable oxygen concentration and to a variable radiant heat flux. The gases emitted from the smoldering reaction pass upwards through a pilot, which consists of a coiled resistance heating wire. In order to compensate for the solid-phase and gas-phase effects of the fire retardants on the piloted transition from smoldering to flaming in Pyrell, it was necessary to assist the process by increasing the power supplied to the smolder igniter and the pilot (compared to that used for non-fire retarded foam). The experiments indicate that the piloted transition from smoldering to flaming occurs when the gaseous mixture at the pilot passes the lean flammability limit. It was found that increasing the oxygen concentration or the external heat flux increases the likelihood of a piloted transition from smoldering to flaming, and generally decreases the time delay to transition. The piloted transition to flaming is observed in oxygen concentrations of 23% and above in both low-density and high-density Pyrell. Comparisons with previous experiments show that the piloted transition from smoldering to flaming is possible under a wider range of external conditions (i.e. lower oxygen concentration) than the spontaneous transition from smoldering to flaming. The results show that the fire retardants in Pyrell are very effective in preventing the piloted transition to flaming in normal air, but Pyrell is susceptible to smoldering and the piloted transition to flaming in oxygen-enriched environments. Therefore, precautions should be taken in the design of applications of Pyrell in oxygen-enriched environments to reduce to the risk of a piloted transition to flaming.

46 CFR 54.15-25 - Minimum relief capacities for cargo tanks containing compressed or liquefied gas.

Code of Federal Regulations, 2012 CFR

2012-10-01

... overpressure permitted shall be in accordance with § 54.15-5. (c) The rate of discharge for heat input of fire... exposure factor for the following tank types: F=1.0 for tanks without insulation located on the open deck. F=0.5 for tanks on the open deck having insulation that has approved fire proofing, thermal...

46 CFR 54.15-25 - Minimum relief capacities for cargo tanks containing compressed or liquefied gas.

Code of Federal Regulations, 2011 CFR

2011-10-01

... overpressure permitted shall be in accordance with § 54.15-5. (c) The rate of discharge for heat input of fire... exposure factor for the following tank types: F=1.0 for tanks without insulation located on the open deck. F=0.5 for tanks on the open deck having insulation that has approved fire proofing, thermal...

46 CFR 54.15-25 - Minimum relief capacities for cargo tanks containing compressed or liquefied gas.

Code of Federal Regulations, 2010 CFR

2010-10-01

... overpressure permitted shall be in accordance with § 54.15-5. (c) The rate of discharge for heat input of fire... exposure factor for the following tank types: F=1.0 for tanks without insulation located on the open deck. F=0.5 for tanks on the open deck having insulation that has approved fire proofing, thermal...

46 CFR 54.15-25 - Minimum relief capacities for cargo tanks containing compressed or liquefied gas.

Code of Federal Regulations, 2014 CFR

2014-10-01

... overpressure permitted shall be in accordance with § 54.15-5. (c) The rate of discharge for heat input of fire... exposure factor for the following tank types: F=1.0 for tanks without insulation located on the open deck. F=0.5 for tanks on the open deck having insulation that has approved fire proofing, thermal...

46 CFR 54.15-25 - Minimum relief capacities for cargo tanks containing compressed or liquefied gas.

Code of Federal Regulations, 2013 CFR

2013-10-01

... overpressure permitted shall be in accordance with § 54.15-5. (c) The rate of discharge for heat input of fire... exposure factor for the following tank types: F=1.0 for tanks without insulation located on the open deck. F=0.5 for tanks on the open deck having insulation that has approved fire proofing, thermal...

The role of maternal acceptance in the relation between community violence exposure and child functioning.

PubMed

Bailey, Beth Nordstrom; Hannigan, John H; Delaney-Black, Virginia; Covington, Chandice; Sokol, Robert J

2006-02-01

Children in the United States are exposed to considerable community violence that has been linked to child functioning. However, not all those exposed, experience negative outcomes. Recent research has focused on factors that "buffer" or protect children from negative consequences of violence exposure. The purpose of this investigation was to examine the potential buffering or moderating role of maternal acceptance in the relationship between community violence exposure and internalizing and externalizing problems. Subjects were 268 urban African American first graders. Community violence exposure was significantly related to symptoms of post-traumatic stress, but did not correlate with either internalizing or externalizing problems for all children, after control for demographics, maternal mental health, and general life stress. However, children's perceptions of maternal acceptance moderated the relationship between violence exposure and internalizing and externalizing problems which included being withdrawn, anxious-depressed, and demonstrating delinquent behavior. Children with the lowest levels of self-reported maternal acceptance were most impacted by community violence. In this sample of urban first graders, low levels of maternal acceptance placed children at greater risk for adverse outcomes associated with community violence exposure compared to moderate and high levels of maternal acceptance.

Differential exposure and acute health impacts of inhaled solid-fuel emissions from rudimentary and advanced cookstoves in female CD-1 mice.

PubMed

Gibbs-Flournoy, Eugene A; Gilmour, M Ian; Higuchi, Mark; Jetter, James; George, Ingrid; Copeland, Lisa; Harrison, Randy; Moser, Virginia C; Dye, Janice A

2018-02-01

There is an urgent need to provide access to cleaner end user energy technologies for the nearly 40% of the world's population who currently depend on rudimentary cooking and heating systems. Advanced cookstoves (CS) are designed to cut emissions and solid-fuel consumption, thus reducing adverse human health and environmental impacts. We hypothesized that, compared to a traditional (Tier 0) three-stone (3-S) fire, acute inhalation of solid-fuel emissions from advanced natural-draft (ND; Tier 2) or forced-draft (FD; Tier 3) stoves would reduce exposure biomarkers and lessen pulmonary and innate immune system health effects in exposed mice. Across two simulated cooking cycles (duration ~ 3h), emitted particulate mass concentrations were reduced 80% and 62% by FD and ND stoves, respectively, compared to the 3-S fire; with corresponding decreases in particles visible within murine alveolar macrophages. Emitted carbon monoxide was reduced ~ 90% and ~ 60%, respectively. Only 3-S-fire-exposed mice had increased carboxyhemoglobin levels. Emitted volatile organic compounds were FD ≪ 3-S-fire ≤ ND stove; increased expression of genes involved in xenobiotic metabolism (COX-2, NQO1, CYP1a1) was detected only in ND- and 3-S-fire-exposed mice. Diminished macrophage phagocytosis was observed in the ND group. Lung glutathione was significantly depleted across all CS groups, however the FD group had the most severe, ongoing oxidative stress. These results are consistent with reports associating exposure to solid fuel stove emissions with modulation of the innate immune system and increased susceptibility to infection. Lower respiratory infections continue to be a leading cause of death in low-income economies. Notably, 3-S-fire-exposed mice were the only group to develop acute lung injury, possibly because they inhaled the highest concentrations of hazardous air toxicants (e.g., 1,3-butadiene, toluene, benzene, acrolein) in association with the greatest number of particles, and particles with the highest % organic carbon. However, no Tier 0-3 ranked CS group was without some untoward health effect indicating that access to still cleaner, ideally renewable, energy technologies for cooking and heating is warranted. Published by Elsevier Inc.

Cardiorespiratory hospitalizations associated with smoke exposure during the 1997, Southeast Asian forest fires.

PubMed

Mott, Joshua A; Mannino, David M; Alverson, Clinton J; Kiyu, Andrew; Hashim, Jamilah; Lee, Tzesan; Falter, Kenneth; Redd, Stephen C

2005-01-01

We investigated the cardiorespiratory health effects of smoke exposure from the 1997 Southeast Asian Forest Fires among persons who were hospitalized in the region of Kuching, Malaysia. We selected admissions to seven hospitals in the Kuching region from a database of all hospital admissions in the state of Sarawak during January 1, 1995 and December 31, 1998. For several cardiorespiratory disease classifications we used Holt-Winters time-series analyses to determine whether the total number of monthly hospitalizations during the forest fire period (August 1 to October 31, 1997), or post-fire period (November 1, 1997 to December 31, 1997) exceeded forecasted estimates established from a historical baseline period of January 1, 1995 to July 31, 1997. We also identified age-specific cohorts of persons whose members were admitted for specific cardiorespiratory problems during January 1 to July 31 of each year (1995--1997). We compared Kaplan-Meier survival curves of time to first readmission for the 1997 cohorts (exposed to the forest fire smoke) with the survival curves for the 1995 and 1996 cohorts (not exposed, pre-fire cohorts). The time-series analyses indicated that statistically significant fire-related increases were observed in respiratory hospitalizations, specifically those for chronic obstructive pulmonary disease (COPD) and asthma. The survival analyses indicated that persons over age 65 years with previous hospital admissions for any cause (chi2(1df) = 5.98, p = 0.015), any cardiorespiratory disease (chi2(1df) = 5.3, p = 0.02), any respiratory disease (chi2(1df) = 7.8, p = 0.005), or COPD (chi2(1df) = 3.9, p = 0.047), were significantly more likely to be rehospitalized during the follow-up period in 1997 than during the follow-up periods in the pre-fire years of 1995 or 1996. The survival functions of the exposed cohorts resumed similar trajectories to unexposed cohorts during the post-fire period of November 1, 1997 to December 31, 1998. Communities exposed to forest fire smoke during the Southeast Asian forest fires of 1997 experienced short-term increases in cardiorespiratory hospitalizations. When an air quality emergency is anticipated, persons over age 65 with histories of respiratory hospitalizations should be preidentified from existing hospitalization records and given priority access to interventions.

Apparatus for controlling the firing of rectifiers in polyphase rectifying circuits

DOEpatents

Yarema, R.J.

1979-09-18

A polyphase rectifier is controlled with precision by a circuit that filters and shifts a reference signal associated with each phase and that starts a ramp signal at a zero crossing of the shifted reference signal. The difference between the ramp signal and an external trigger signal is used to generate a pulse that switches power rectifiers into conduction. The circuit reduces effects of variations that introduce subharmonics into a rectified signal and it can be used for constant or time-varying external trigger signals.

Engineering Strategies and Methods for Avoiding Air-Quality Externalities: Dispersion Modeling, Home Energy Conservation, and Scenario Planning

NASA Astrophysics Data System (ADS)

Knox, Andrew James

Energy conservation can improve air quality by reducing emissions from fuel combustion. The human health value retained through better air quality can then offset the cost of energy conservation. Through this thesis' innovative yet widely-accessible combination of air pollution dispersion modeling and atmospheric chemistry, it is estimated that the health value retained by avoiding emissions from Ontario's former coal-fired generating stations is 5.74/MWh (using an upper-bound value of 265,000 per year of life lost). This value is combined with energy modeling of homes in the first-ever assessment of the air-quality health benefits of low-energy buildings. It is shown that avoided health damages can equal 7% of additional construction costs of energy efficient buildings in Ontario. At 7%, health savings are a significant item in the cost analysis of efficient buildings. Looking to energy efficiency in the context of likely future low-resource natural gas scenarios, building efficient buildings today is shown to be more economically efficient than any building retrofit option. Considering future natural gas scarcity in the context of Ontario's Long-Term Energy Plan reveals that Ontario may be forced to return to coal-fired electricity. Projected coal use would result in externalities greater than $600 million/year; 80% more than air-quality externalities from Ontario's electricity in 1985. Radically aggressive investment in electricity conservation (75% reduction per capita by 2075) is one promising path forward that keeps air-quality externalities below 1985 levels. Non-health externalities are an additional concern, the quantification, and ultimately monetization, of which could be practical using emerging air pollution monitoring technologies. Energy, conservation, energy planning, and energy's externalities form a complex situation in which today's decisions are critical to a successful future. It is clear that reducing the demand for energy is essential and that there are economically efficient conservation opportunities, particularly in the building sector, being missed.

Fires at storage sites of organic materials, waste fuels and recyclables.

PubMed

Ibrahim, Muhammad Asim; Alriksson, Stina; Kaczala, Fabio; Hogland, William

2013-09-01

During the last decade, the European Union has enforced the diversion of organic wastes and recyclables to waste management companies operating incineration plants, composting plants and recycling units instead of landfills. The temporary storage sites have been established as a buffer against fluctuations in energy demand throughout the year. Materials also need to be stored at temporary storage sites before recovery and recycling. However, regulations governing waste fuel storage and handling have not yet been developed, and, as a result, companies have engaged in risky practices that have resulted in a high number of fire incidents. In this study, a questionnaire survey was distributed to 249 of the 400 members of Avfall Sverige (Swedish Waste Management Association), which represents the waste management of 95% of the Swedish population. Information regarding 122 storage facilities owned by 69 companies was obtained; these facilities were responsible for the storage of 47% of the total treated waste (incineration + digestion + composting) in 2010 in Sweden. To identify factors related to fire frequency, the questionnaire covered the amounts of material handled and burnt per year, financial losses due to fires, storage duration, storage method and types of waste. The results show that 217 fire incidents corresponded to 170 kilotonnes of material burnt and cumulative losses of 49 million SEK (€4.3 million). Fire frequency and amount of material burnt per fire was found to be dependent upon type of management group (waste operator). Moreover, a correlation was found between fire frequency and material recycled during past years. Further investigations of financial aspects and externalities of fire incidents are recommended.

Oil well fires of Operation Desert Storm--defining troop exposures and determining health risks.

PubMed

Heller, Jack M

2011-07-01

During Operation Desert Storm, in February 1991, Iraqi troops began burning Kuwaiti oil wells. Almost immediately there was concern about possible adverse health effects in U.S. personnel exposed to crude oil combustion products. Combustions products were predicted from the known composition of Kuwaiti crude oil. Monitoring sites were established in Saudi Arabia and Kuwait; about 5,000 environmental samples were studied. Data collected were used to develop health risk assessments for the geographic areas sampled. This initial approach to assessing risk had to be greatly expanded when Congress passed Public Law 102-190, requiring development of means to calculate environmental exposures for individual U.S. service members. To estimate daily exposure levels for the entire area over 10 months for all U.S. troops, air dispersion modeling was used in conjunction with satellite imagery and geographic information system technology. This methodology made it possible to separate the risk caused by oil fire smoke from the total risk from all sources for each service member. The U.S. military responses to health concerns related to the oil well fires and to Public Law 102-190 were reviewed. Consideration was given to changes in technology, practices, and policies over the last two decades that might impact a similar contemporary response.

NIOSH testimony on Kuwait before the subcommittee on hospitals and health care, committee on veterans' affairs by J. S. Andrews, September 16, 1992

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

Not Available

1992-09-16

The testimony summarizes potential adverse health effects related to service in the Persian Gulf as presented by the Department of Health and Human Services. An estimated 9,000 workers from 43 different countries battled the burning oil wells in Kuwait from February 1991 through early November 1991 when the last was capped. Exposures and health effects in US military personnel, Kuwaiti citizens, and fire fighters were described. The hazards to the soldiers were largely dependent on the concentration of the pollutants in the air near the camps. Fortunately, the plume from the fires rose up to 10,000 and 12,000 feet, mixedmore » with the air and then dispersed for several thousand miles downwind over a period of several weeks. The particles and gases contained in the plume were diluted as the plume travelled. Even so, some minor respiratory problems were present among the soldiers. Some of the hydrocarbons measured at low concentrations have been shown to produce cancer in laboratory animals only when present at higher levels of exposure. Based on the exposure information gathered, the author concludes that there will not likely be a detectable increase in lung cancer in Gulf War Veterans as a result of the oil well fires.« less

FASH and MASH: female and male adult human phantoms based on polygon mesh surfaces: II. Dosimetric calculations

NASA Astrophysics Data System (ADS)

Kramer, R.; Cassola, V. F.; Khoury, H. J.; Vieira, J. W.; de Melo Lima, V. J.; Robson Brown, K.

2010-01-01

Female and male adult human phantoms, called FASH (Female Adult meSH) and MASH (Male Adult meSH), have been developed in the first part of this study using 3D animation software and anatomical atlases to replace the image-based FAX06 and the MAX06 voxel phantoms. 3D modelling methods allow for phantom development independent from medical images of patients, volunteers or cadavers. The second part of this study investigates the dosimetric implications for organ and tissue equivalent doses due to the anatomical differences between the new and the old phantoms. These differences are mainly caused by the supine position of human bodies during scanning in order to acquire digital images for voxel phantom development. Compared to an upright standing person, in image-based voxel phantoms organs are often coronally shifted towards the head and sometimes the sagittal diameter of the trunk is reduced by a gravitational change of the fat distribution. In addition, volumes of adipose and muscle tissue shielding internal organs are sometimes too small, because adaptation of organ volumes to ICRP-based organ masses often occurs at the expense of general soft tissues, such as adipose, muscle or unspecified soft tissue. These effects have dosimetric consequences, especially for partial body exposure, such as in x-ray diagnosis, but also for whole body external exposure and for internal exposure. Using the EGSnrc Monte Carlo code, internal and external exposure to photons and electrons has been simulated with both pairs of phantoms. The results show differences between organ and tissue equivalent doses for the upright standing FASH/MASH and the image-based supine FAX06/MAX06 phantoms of up to 80% for external exposure and up to 100% for internal exposure. Similar differences were found for external exposure between FASH/MASH and REGINA/REX, the reference voxel phantoms of the International Commission on Radiological Protection. Comparison of effective doses for external photon exposure showed good agreement between FASH/MASH and REGINA/REX, but large differences between FASH/MASH and the mesh-based RPI_AM and the RPI_AF phantoms, developed at the Rensselaer Polytechnic Institute (RPI).

Method for producing flame retardant porous products and products produced thereby

DOEpatents

Salyer, Ival O.

1998-08-04

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame.

Method for producing flame retardant porous products and products produced thereby

DOEpatents

Salyer, I.O.

1998-08-04

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame. 1 fig.

Method for Producing Flame Retardant Porous Products and Products Produced Thereby

DOEpatents

Salyer, Ival O.

1998-08-04

A method for fire retarding porous products used for thermal energy storage and products produced thereby is provided. The method includes treating the surface of the phase change material-containing porous products with a urea fire-retarding agent. Upon exposure to a flame, the urea forms an adduct with the phase change material which will not sustain combustion (is self-extinguishing) in air. No halogens or metal oxides are contained in the fire retardant, so no potentially noxious halide smoke or fumes are emitted if the product is continuously exposed to a flame.

NEW IMPROVEMENTS TO MFIRE TO ENHANCE FIRE MODELING CAPABILITIES.

PubMed

Zhou, L; Smith, A C; Yuan, L

2016-06-01

NIOSH's mine fire simulation program, MFIRE, is widely accepted as a standard for assessing and predicting the impact of a fire on the mine ventilation system and the spread of fire contaminants in coal and metal/nonmetal mines, which has been used by U.S. and international companies to simulate fires for planning and response purposes. MFIRE is a dynamic, transient-state, mine ventilation network simulation program that performs normal planning calculations. It can also be used to analyze ventilation networks under thermal and mechanical influence such as changes in ventilation parameters, external influences such as changes in temperature, and internal influences such as a fire. The program output can be used to analyze the effects of these influences on the ventilation system. Since its original development by Michigan Technological University for the Bureau of Mines in the 1970s, several updates have been released over the years. In 2012, NIOSH completed a major redesign and restructuring of the program with the release of MFIRE 3.0. MFIRE's outdated FORTRAN programming language was replaced with an object-oriented C++ language and packaged into a dynamic link library (DLL). However, the MFIRE 3.0 release made no attempt to change or improve the fire modeling algorithms inherited from its previous version, MFIRE 2.20. This paper reports on improvements that have been made to the fire modeling capabilities of MFIRE 3.0 since its release. These improvements include the addition of fire source models of the t-squared fire and heat release rate curve data file, the addition of a moving fire source for conveyor belt fire simulations, improvement of the fire location algorithm, and the identification and prediction of smoke rollback phenomena. All the improvements discussed in this paper will be termed as MFIRE 3.1 and released by NIOSH in the near future.

Chronic alcohol disrupts dopamine receptor activity and the cognitive function of the medial prefrontal cortex.

PubMed

Trantham-Davidson, Heather; Burnett, Elizabeth J; Gass, Justin T; Lopez, Marcelo F; Mulholland, Patrick J; Centanni, Samuel W; Floresco, Stan B; Chandler, L Judson

2014-03-05

Dopamine (DA) receptors in the medial prefrontal cortex (mPFC) exert powerful effects on cognition by modulating the balance between excitatory and inhibitory neurotransmission. The present study examined the impact of chronic intermittent ethanol (CIE) exposure on cognitive function and DA receptor-mediated neurotransmission in the rat mPFC. Consistent with alterations in executive function in alcoholics, CIE-exposed rats exhibited deficits in behavioral flexibility in an operant set-shifting task. Since alterations in dopaminergic neurotransmission in the mPFC have been implicated in a number of behavioral disorders including addiction, studies were then performed in the adult acute slice preparation to examine changes in DA receptor function in the mPFC following CIE exposure. In slices obtained from control rats, DA receptor stimulation was observed to exert complex actions on neuronal firing and synaptic neurotransmission that were not only dependent upon the particular receptor subtype but also whether it was a pyramidal cell or a fast-spiking interneuron. In contrast to slices from control rats, there was a near complete loss of the modulatory actions of D2/D4 receptors on cell firing and neurotransmission in slices obtained immediately, 1 and 4 weeks after the last day of CIE exposure. This loss did not appear to be associated with changes in receptor expression. In contrast, CIE exposure did not alter D1 receptor function or mGluR1 modulation of firing. These studies are consistent with the suggestion that chronic alcohol exposure disrupts cognitive function at least in part through disruption of D2 and D4 receptor signaling in mPFC.

Reproductive function in relation to duty assignments among military personnel.

PubMed

Schrader, S M; Langford, R E; Turner, T W; Breitenstein, M J; Clark, J C; Jenkins, B L; Lundy, D O; Simon, S D; Weyandt, T B

1998-01-01

As a follow-up to the pilot study of semen quality of soldiers with various military assignments a larger, more complete study was conducted. Soldiers were recruited at Fort Hood, Texas. Thirty-three men were exposed to radar as part of their duty assignment in the Signal Corps, 57 men were involved with firing the 155 mm howitzer (potential lead exposure), and 103 soldiers had neither lead nor radar exposure and served as the comparison control group. Both serum and urinary follicle-stimulating hormone and luteinizing hormone and serum, salivary, and urine testosterone levels were determined in all men. A complete semen analysis was conducted on each soldier. For statistical analysis, the primary study variables were: sperm concentration, sperm/ejaculate, semen volume, percent normal morphology, percent motile, percent viable (both vital stain and hypoosmotic swelling), curvilinear velocity, straight-line velocity, linearity, sperm head length, width, area, and perimeter. Variables were adjusted for significant confounders (e.g., abstinence, sample age, race). No statistical differences (P < 0.05) were observed in any measurement. While these results are in agreement with two previous studies assessing soldiers firing the 155-mm howitzer, they contradict our previous report indicating that radar exposure caused a significant decrease in sperm numbers. A possible explanation is that the radar exposure in this study was that used in Signal Corps operations while the men in the previous study were using different radar as part of military intelligence operations. The data presented here in men firing the 155-mm howitzer combined with the results from the previous studies confirms that there are no deficits in semen quality in these men. The contradiction between the results of the radar exposure studies indicates that more data are needed to evaluate the relationship of military radar and male reproductive health.

The role of anger and ongoing stressors in mental health following a natural disaster.

PubMed

Forbes, David; Alkemade, Nathan; Waters, Elizabeth; Gibbs, Lisa; Gallagher, Colin; Pattison, Phillipa; Lusher, Dean; MacDougall, Colin; Harms, Louise; Block, Karen; Snowdon, Elyse; Kellet, Connie; Sinnott, Vikki; Ireton, Greg; Richardson, John; Bryant, Richard A

2015-08-01

Research has established the mental health sequelae following disaster, with studies now focused on understanding factors that mediate these outcomes. This study focused on anger, alcohol, subsequent life stressors and traumatic events as mediators in the development of mental health disorders following the 2009 Black Saturday Bushfires, Australia's worst natural disaster in over 100 years. This study examined data from 1017 (M = 404, F = 613) adult residents across 25 communities differentially affected by the fires and participating in the Beyond Bushfires research study. Data included measures of fire exposure, posttraumatic stress disorder, depression, alcohol abuse, anger and subsequent major life stressors and traumatic events. Structural equation modeling assessed the influence of factors mediating the effects of fire exposure on mental health outcomes. Three mediation models were tested. The final model recorded excellent fit and observed a direct relationship between disaster exposure and mental health outcomes (b = .192, p < .001) and mediating relationships via Anger (b = .102, p < .001) and Major Life Stressors (b = .128, p < .001). Each gender was compared with multiple group analyses and while the mediation relationships were still significant for both genders, the direct relationship between exposure and outcome was no longer significant for men (p = .069), but remained significant (b = .234, p < .001) for women. Importantly, anger and major life stressors mediate the relationship between disaster exposure and development of mental health problems. The findings have significant implications for the assessment of anger post disaster, the provision of targeted anger-focused interventions and delivery of government and community assistance and support in addressing ongoing stressors in the post-disaster context to minimize subsequent mental health consequences. © The Royal Australian and New Zealand College of Psychiatrists 2015.

Recurrent fires and environment shape the vegetation in Quercus suber L. woodlands and maquis.

PubMed

Schaffhauser, Alice; Curt, Thomas; Véla, Errol; Tatoni, Thierry

2012-06-01

The effects of fire recurrence on vegetation patterns in Quercus suber L. and Erica-Cistus communities in Mediterranean fire-prone ecosystems of south-eastern France were examined on stands belonging to 5 fire classes, corresponding to different numbers of fires (from 0 to 4) and time intervals between fires since 1959. A common pool of species was identified among the plots, which was typical of both open and closed maquis. Fire recurrence reduced the abundance of trees and herbs, whereas it increased the abundance of small shrubs. Richness differed significantly between the most contrasting classes of fire recurrence, with maximal values found in control plots and minimal values in plots that had burned recurrently and recently. Equitability indices did not vary significantly, in contrast to Shannon's diversity index which mostly correlated with richness. Forest ecosystems that have burnt once or twice in the last 50 years were resilient; that is to say they recovered a biomass and composition similar to that of the pre-fire state. However, after more than 3-4 fires, shrubland communities displayed lower species richness and diversity indices than unburned plots. The time since the last fire and the number of fires were the most explanatory fire variables, governing the structure of post-fire plant communities. However, environmental factors, such as slope or exposure, also made a significant contribution. Higher rates of fire recurrence can affect the persistence or expansion of shrublands in the future, as observed in other Mediterranean areas. Copyright © 2012 Académie des sciences. Published by Elsevier SAS. All rights reserved.

Thermal analysis of GFRP-reinforced continuous concrete decks subjected to top fire

NASA Astrophysics Data System (ADS)

Hawileh, Rami A.; Rasheed, Hayder A.

2017-12-01

This paper presents a numerical study that investigates the behavior of continuous concrete decks doubly reinforced with top and bottom glass fiber reinforced polymer (GFRP) bars subjected to top surface fire. A finite element (FE) model is developed and a detailed transient thermal analysis is performed on a continuous concrete bridge deck under the effect of various fire curves. A parametric study is performed to examine the top cover thickness and the critical fire exposure curve needed to fully degrade the top GFRP bars while achieving certain fire ratings for the deck considered. Accordingly, design tables are prepared for each fire curve to guide the engineer to properly size the top concrete cover and maintain the temperature in the GFRP bars below critical design values in order to control the full top GFRP degradation. It is notable to indicate that degradation of top GFRP bars do not pose a collapse hazard but rather a serviceability concern since cracks in the negative moment region widen resulting in simply supported spans.

Evaluation of a headspace solid-phase microextraction method for the analysis of ignitable liquids in fire debris.

PubMed

Fettig, Ina; Krüger, Simone; Deubel, Jan H; Werrel, Martin; Raspe, Tina; Piechotta, Christian

2014-05-01

The chemical analysis of fire debris represents a crucial part in fire investigations to determine the cause of a fire. A headspace solid-phase microextraction (HS-SPME) procedure for the detection of ignitable liquids in fire debris using a fiber coated with a mixture of three different sorbent materials (Divinylbenzene/Carboxen/Polydimethylsiloxane, DVB/CAR/PDMS) is described. Gasoline and diesel fuel were spiked upon a preburnt matrix (wood charcoal), extracted and concentrated with HS-SPME and then analyzed with gas chromatography/mass spectrometry (GC/MS). The experimental conditions--extraction temperature, incubation and exposure time--were optimized. To assess the applicability of the method, fire debris samples were prepared in the smoke density chamber (SDC) and a controlled-atmosphere cone calorimeter. The developed methods were successfully applied to burnt particleboard and carpet samples. The results demonstrate that the procedure that has been developed here is suitable for detecting these ignitable liquids in highly burnt debris. © 2013 American Academy of Forensic Sciences.

A Home Ignition Assessment Model Applied to Structures in the Wildland-Urban Interface

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

Biswas, Kaushik; Werth, David; Gupta, Narendra

2013-01-01

The issue of exterior fire threat to buildings, from either wildfires in the wildland-urban interface or neighboring structure fires, is critically important. To address this, theWildfire Ignition Resistant Home Design (WIRHD) program was initiated. The WIRHD program developed a tool, theWildFIREWizard, that will allow homeowners to estimate the external fire threat to their homes based on specific features and characteristics of the homes and yards. The software then makes recommendations to reduce the threat. The inputs include the structural and material features of the home and information about any ignition sources or flammable objects in its immediate vicinity, known asmore » the home ignition zone. The tool comprises an ignition assessment model that performs explicit calculations of the radiant and convective heating of the building envelope from the potential ignition sources. This article describes a series of material ignition and flammability tests that were performed to calibrate and/or validate the ignition assessment model. The tests involved exposing test walls with different external siding types to radiant heating and/or direct flame contact.The responses of the test walls were used to determine the conditions leading to melting, ignition, or any other mode of failure of the walls. Temperature data were used to verify the model predictions of temperature rises and ignition times of the test walls.« less

Prospective Assessment of Chronic Multisymptom Illness Reporting Possibly Associated with Open-Air Burn Pit Smoke Exposure in Iraq

DTIC Science & Technology

2012-06-01

clearly implicating any specific war exposure as a cause of postwar symptoms, which is noteworthy, given the large and contin- ued military presence in...dioxide, sulfur dioxide, and polycyclic aromatic hydrocarbons are being released in the smoke from the fires, and many are known carcinogens and may cause ...exposure by providing benefits to veterans who self-report this type of exposure and have a variety of health conditions.26 The Millennium Cohort Study was

Comparative techniques of medial rectus muscle retraction for endoscopic exposure of the medial intraconal space.

PubMed

Lin, Giant C; Freitag, Suzanne K; Kocharyan, Armine; Yoon, Michael K; Lefebvre, Daniel R; Bleier, Benjamin S

2016-05-01

The medial rectus muscle (MRM) is the medial boundary to the intraconal space of the orbit, and retraction of the MRM is oftentimes necessary for endoscopic removal of intraconal tumors, e.g., orbital hemangioma. We evaluated each of the reported methods of MRM retraction for endoscopic orbital surgery and quantified the degree of intraconal exposure conferred by each method. Eight orbits from four cadaver heads were dissected. In each orbit, medial orbital decompression was performed and the MRM was retracted by using four previously described techniques: (1) external MRM retraction at the globe insertion point by using vessel loop (external group), (2) transseptal MRM retraction by using vessel loop (transseptal group), (3) transchoanal retraction of the MRM by using vessel loop (choanal group), and (4) transseptal four-handed technique by using double ball retraction by a second surgeon (transseptal double ball group). The length, height, and area of exposure of the medial intraconal space were quantified and compared. The average ± standard deviation (SD) anterior-posterior exposures for the external group, transseptal group, and transseptal double ball group were 17.51 ± 3.39 mm, 16.59 ± 4.16 mm, and 18.0 ± 15.25 mm, respectively. The choanal group provided significantly less exposure (12.39 ± 3.44 mm, p = 0.049) than the other groups. The average ± SD vertical exposures for the transseptal group, choanal group, and transseptal double ball group were 12.53 ± 4.38 mm, 13.05 ± 5.86 mm, and 13.57 ± 3.74 mm, respectively. The external group provided significantly less exposure (4.51 ± 1.56 mm, p = 0.0072) than the other groups. The transseptal and transseptal double ball groups provided the greatest total access by surface area (58.88 ± 26.96 mm(2) and 62.94 ± 34.74 mm(2), respectively) compared with the external and choanal groups (34.82 ± 23.37 mm(2) and 43.10 ± 23.68 mm(2), respectively). Although the transseptal trajectory of MRM retraction was optimal, the difference in total area of exposure between the static vessel loop retraction and the dynamic, four-handed technique with double ball instrument retraction was not significant. Of note, the exposure provided by the choanal technique required the surgeon to work both above and below the muscle. Retraction of the MRM toward the choanae provided the least length of exposure, and external retraction exposed the least height and total area. Transseptal MRM retraction was most favorable and provided the largest endoscopic corridor to the medial intraconal space. A four-handed approach for endoscopic intraconal surgery of the orbit may offer advantages in dynamic adjustments in retraction.

Soot, organics and ultrafine ash from air- and oxy-fired coal combustion

EPA Science Inventory

This paper is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practically relevant s...

Soot, organics, and ultrafine ash from air- and oxy-fired coal combustion

EPA Science Inventory

This paper/presentation is concerned with determining the effects of oxy-combustion of coal on the composition of the ultrafine fly ash. To this end, a 10 W externally heated entrained flow furnace was modified to allow the combustion of pulverized coal in flames under practicall...

Incipient failure detection of space shuttle main engine turbopump bearings using vibration envelope detection

NASA Technical Reports Server (NTRS)

Hopson, Charles B.

1987-01-01

The results of an analysis performed on seven successive Space Shuttle Main Engine (SSME) static test firings, utilizing envelope detection of external accelerometer data are discussed. The results clearly show the great potential for using envelope detection techniques in SSME incipient failure detection.

Do hunger and exposure to food affect scores on a measure of hedonic hunger? An experimental study.

PubMed

Witt, Ashley A; Raggio, Greer A; Butryn, Meghan L; Lowe, Michael R

2014-03-01

Research suggests that visceral bodily states, such as hunger, can affect participants' responses on self-report measures of eating behavior. The present study evaluated the influence of hunger and exposure to palatable food on self-reported hedonic appetite, measured using the Power of Food Scale (PFS). A secondary aim was to evaluate the effects of these manipulations on self-reported external eating and disinhibition. Participants (N=67) ate a standardized meal followed by a 4-h fast. Participants were randomized to one of four groups (Fasted/Food Absence, Fasted/Food Exposure, Fed/Food Absence, or Fed/Food Exposure). In Phase I of the experiment (Hunger Manipulation), participants randomized to the "Fed" group drank a protein shake, while those in the "Fasted" group did not receive a shake. In Phase II (Palatable Food Exposure), participants in the "Food Exposure" group were visually exposed to palatable food items, while "Food Absence" participants were not. All participants completed the PFS, Dutch Eating Behavior Questionnaire External Eating subscale, and the Disinhibition subscale from the Eating Inventory during Phase II. Results showed no significant main or interactive effects of Hunger condition or Food Exposure condition on PFS, External Eating, or Disinhibition scores (all p's<.33). All effect sizes were small (partial etas squared ⩽.015). Manipulation checks confirmed that the intended hunger and exposure interventions were successful. Results suggest that relatively short fasting periods (e.g., 4h) analogous to typical breaks between meals are not associated with changes in scores on the PFS, External Eating, or Disinhibition scales. Hedonic hunger, at least as measured by the PFS, may represent a relatively stable construct that is not substantially affected by daily variations in hunger. In addition, individual differences in exposure to food in the immediate environment are unlikely to confound research using these measures. Copyright © 2013 Elsevier Ltd. All rights reserved.

Solid cancer mortality associated with chronic external radiation exposure at the French atomic energy commission and nuclear fuel company.

PubMed

Metz-Flamant, C; Samson, E; Caër-Lorho, S; Acker, A; Laurier, D

2011-07-01

Studies of nuclear workers make it possible to directly quantify the risks associated with ionizing radiation exposure at low doses and low dose rates. Studies of the CEA (Commissariat à l'Energie Atomique) and AREVA Nuclear Cycle (AREVA NC) cohort, currently the most informative such group in France, describe the long-term risk to nuclear workers associated with external exposure. Our aim is to assess the risk of mortality from solid cancers among CEA and AREVA NC nuclear workers and its association with external radiation exposure. Standardized mortality ratios (SMRs) were calculated and internal Poisson regressions were conducted, controlling for the main confounding factors [sex, attained age, calendar period, company and socioeconomic status (SES)]. During the period 1968-2004, there were 2,035 solid cancers among the 36,769 CEA-AREVA NC workers. Cumulative external radiation exposure was assessed for the period 1950-2004, and the mean cumulative dose was 12.1 mSv. Mortality rates for all causes and all solid cancers were both significantly lower in this cohort than in the general population. A significant excess of deaths from pleural cancer, not associated with cumulative external dose, was observed, probably due to past asbestos exposure. We observed a significant excess of melanoma, also unassociated with dose. Although cumulative external dose was not associated with mortality from all solid cancers, the central estimated excess relative risk (ERR) per Sv of 0.46 for solid cancer mortality was higher than the 0.26 calculated for male Hiroshima and Nagasaki A-bomb survivors 50 years or older and exposed at the age of 30 years or older. The modification of our results after stratification for SES demonstrates the importance of this characteristic in occupational studies, because it makes it possible to take class-based lifestyle differences into account, at least partly. These results show the great potential of a further joint international study of nuclear workers, which should improve knowledge about the risks associated with chronic low doses and provide useful risk estimates for radiation protection.

Effects of Prenatal Cocaine Exposure on Early Sexual Behavior: Gender Difference in Externalizing Behavior as a Mediator

PubMed Central

Min, Meeyoung O.; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T.

2015-01-01

Background Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Methods Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year old adolescents participated in a prospective longitudinal study. Adolescents’ sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Results Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI= 1.2 – 4.1, p < .01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4 – 4.7, p < .002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. Conclusions PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. PMID:26088698

Effects of prenatal cocaine exposure on early sexual behavior: Gender difference in externalizing behavior as a mediator.

PubMed

Min, Meeyoung O; Minnes, Sonia; Lang, Adelaide; Yoon, Susan; Singer, Lynn T

2015-08-01

Prenatal cocaine exposure (PCE) is associated with increased risk for externalizing behavior problems; childhood externalizing behavior problems are linked with subsequent early sexual behavior. The present study examined the effects of PCE on early sexual initiation (sexual intercourse prior to age 15) and whether externalizing behavior in preadolescence mediated the relationship. Three hundred fifty-four (180 PCE and 174 non-cocaine exposed; 192 girls, 142 boys), primarily African-American, low socioeconomic status, 15-year-old adolescents participated in a prospective longitudinal study. Adolescents' sexual behavior was assessed at 15 years using the Youth Risk Behavior Surveillance System. Externalizing behavior was assessed at 12 years using the Youth Self-Report. Logistic regression models indicated that adolescents with PCE (n=69, 38%) were 2.2 times more likely (95% CI=1.2-4.1, p<.01) to engage in early sexual intercourse than non-exposed peers (n=49, 28%) controlling for covariates. This relationship was fully mediated by self-reported externalizing behavior in girls but not in boys, suggesting childhood externalizing behavior as a gender moderated mediator. Blood lead level during preschool years was also related to a greater likelihood of early sexual intercourse (OR=2.6, 95% CI=1.4-4.7, p<.002). Greater parental monitoring decreased the likelihood of early sexual intercourse, while violence exposure increased the risk. PCE is related to early sexual intercourse, and externalizing behavior problems mediate PCE effects in female adolescents. Interventions targeting externalizing behavior may reduce early sexual initiation and thereby reduce HIV risk behaviors and early, unplanned pregnancy in girls with PCE. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Properties of conductive thick-film inks

NASA Technical Reports Server (NTRS)

Holtze, R. F.

1972-01-01

Ten different conductive inks used in the fabrication of thick-film circuits were evaluated for their physical and handling properties. Viscosity, solid contents, and spectrographic analysis of the unfired inks were determined. Inks were screened on ceramic substrates and fired for varying times at specified temperatures. Selected substrates were given additional firings to simulate the heat exposure received if thick-film resistors were to be added to the same substrate. Data are presented covering the (1) printing characteristics, (2) solderability using Sn-63 and also a 4 percent silver solder, (3) leach resistance, (4) solder adhesion, and (5) wire bonding properties. Results obtained using different firing schedules were compared. A comparison was made between the various inks showing general results obtained for each ink. The changes in firing time or the application of a simulated resistor firing had little effect on the properties of most inks.

Candidate materials for advanced fire-resistant photovoltaic modules

NASA Technical Reports Server (NTRS)

Sugimura, R. S.; Otth, D. H.; Ross, R. G., Jr.; Arnett, J. C.; Samuelson, G.

1985-01-01

A cooperative, cost-sharing research effort to develop a technology base required to construct fire-ratable photovoltaic modules has resulted in the identification of several high-temperature, back-surface candidate materials capable of raising the fire-resistance of modules using hydrocarbon encapsulants to Class A and B levels. Advanced experimental module configurations have been developed using back surfaces consisting of Kapton, Tedlar laminates, metal-foils, and fiberglass materials with high-temperature coatings. Test results (October 1984; March 1985; May 1985; and October 1985) indicate that several of these advanced module configurations are capable of achieving Class B fire-resistance levels, while a few configurations can achieve Class A levels. The paper summarizes activities to date, discussing flammability failure mechanisms, time-temperature profiles, and results of Block V environmental exposure tests of a candidate material suitable for both Class B and Class A fire-resistance levels.

Urodynamic function during sleep-like brain states in urethane anesthetized rats.

PubMed

Crook, J; Lovick, T

2016-01-28

The aim was to investigate urodynamic parameters and functional excitability of the periaqueductal gray matter (PAG) during changes in sleep-like brain states in urethane anesthetized rats. Simultaneous recordings of detrusor pressure, external urethral sphincter (EUS) electromyogram (EMG), cortical electroencephalogram (EEG), and single-unit activity in the PAG were made during repeated voiding induced by continuous infusion of saline into the bladder. The EEG cycled between synchronized, high-amplitude slow wave activity (SWA) and desynchronized low-amplitude fast activity similar to slow wave and 'activated' sleep-like brain states. During (SWA, 0.5-1.5 Hz synchronized oscillation of the EEG waveform) voiding became more irregular than in the 'activated' brain state (2-5 Hz low-amplitude desynchronized EEG waveform) and detrusor void pressure threshold, void volume threshold and the duration of bursting activity in the external urethral sphincter EMG were raised. The spontaneous firing rate of 23/52 neurons recorded within the caudal PAG and adjacent tegmentum was linked to the EEG state, with the majority of responsive cells (92%) firing more slowly during SWA. Almost a quarter of the cells recorded (12/52) showed phasic changes in firing rate that were linked to the occurrence of voids. Inhibition (n=6), excitation (n=4) or excitation/inhibition (n=2) was seen. The spontaneous firing rate of 83% of the micturition-responsive cells was sensitive to changes in EEG state. In nine of the 12 responsive cells (75%) the responses were reduced during SWA. We propose that during different sleep-like brain states changes in urodynamic properties occur which may be linked to changing excitability of the micturition circuitry in the periaqueductal gray. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Automated external defibrillator (AED) utilization rates and reasons fire and police first responders did not apply AEDs.

PubMed

Lerner, E Brooke; Billittier, Anthony J; Newman, Mary M; Groh, William J

2002-01-01

To determine the rate at which fire and police first responders (FRs) apply automated external defibrillators (AEDs) and to ascertain reasons for not applying them. Twenty-one emergency medical services (EMS) systems whose FRs had been supplied with AEDs by a philanthropic foundation provided data for all out-of-hospital cardiac arrest (OHCA) patients. Data including the incidence of AED application and explanations for not applying AEDs were analyzed using descriptive statistics. A total of 2,456 OHCAs were reported. AED application information was available for 2,439 patients and revealed that FRs had not applied AEDs to 1,025 patients (42%). Fire FRs were more likely than police FRs to have applied AEDs (relative risk 1.87, 95% confidence interval 1.65-2.12). Reasons for not applying AEDs were listed for 664 (65%) of the OHCA patients to whom AEDs had not been applied. The predominant reason the FRs did not apply an AED was that the transporting ambulance defibrillator had already been applied (74%). However, when response times for FRs and the transporting ambulances were compared for these OHCA patients, it was found that the transporting ambulances arrived after the FRs 23% the time, simultaneously with the FRs 45% of the time, and before the FRs only 32% of the time. Fire and police FRs did not apply AEDs to a significant number of OHCA patients. Use of the transport ambulance defibrillator was the primary reason given for not applying the FR AED. Given low AED application rates by FRs, future studies are needed to determine the characteristics of communities in which equipping FRs with AEDs is the most beneficial deployment strategy, and how to increase AED application by FRs in communities with FR AED programs.

Singing-related neural activity distinguishes two putative pallidal cell types in the songbird basal ganglia: comparison to the primate internal and external pallidal segments

PubMed Central

Goldberg, Jesse H.; Adler, Avital; Bergman, Hagai; Fee, Michale S.

2010-01-01

The songbird area X is a basal ganglia homologue that contains two pallidal cell types—local neurons that project within the basal ganglia and output neurons that project to the thalamus. Based on these projections, it has been proposed that these classes are structurally homologous to the primate external (GPe) and internal (GPi) pallidal segments. To test the hypothesis that the two area X pallidal types are functionally homologous to GPe and GPi neurons, we recorded from neurons in area X of singing juvenile male zebra finches, and directly compare their firing patterns to neurons recorded in the primate pallidus. In area X, we find two cell classes that exhibited high firing (HF) rates (>60Hz) characteristic of pallidal neurons. HF-1 neurons, like most GPe neurons we examined, exhibited large firing rate modulations, including bursts and long pauses. In contrast, HF-2 neurons, like GPi neurons, discharged continuously without bursts or long pauses. To test if HF-2 neurons were the output neurons that project to the thalamus, we next recorded directly from pallidal axon terminals in thalamic nucleus DLM, and found that all terminals exhibited singing-related firing patterns indistinguishable from HF-2 neurons. Our data show that singing-related neural activity distinguishes two putative pallidal cell types in area X: thalamus-projecting neurons that exhibit activity similar to the primate GPi, and non-thalamus-projecting neurons that exhibit activity similar to the primate GPe. These results suggest that song learning in birds and motor learning in mammals employ conserved basal ganglia signaling strategies. PMID:20484651

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 10 Energy 4 2010-01-01 2010-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 10 Energy 4 2011-01-01 2011-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 10 Energy 4 2014-01-01 2014-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 10 Energy 4 2012-01-01 2012-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

10 CFR 835.204 - Planned special exposures.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 10 Energy 4 2013-01-01 2013-01-01 false Planned special exposures. 835.204 Section 835.204 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Standards for Internal and External Exposure § 835.204 Planned special exposures. (a) A planned special exposure may be authorized for a radiological worker to...

Health effects after firing small arms comparing leaded and unleaded ammunition.

PubMed

Voie, Øyvind; Borander, Anne-Katrine; Sikkeland, Liv Ingunn Bjoner; Grahnstedt, Svein; Johnsen, Arnt; Danielsen, Tor Erik; Longva, Kjetil; Kongerud, Johny

2014-12-01

A number of Norwegian soldiers have reported health problems after live-fire training using the HK416 rifle. The objective of this study was to characterize gaseous and particulate emissions from three different types of ammunition, and record the health effects after exposure to emissions from live-firing. Fifty-five healthy, non-smoking men (mean age 40 years) were recruited and divided randomly into three groups, one for each type of ammunition. All subjects fired the HK416 rifle in a semi-airtight tent for 60 min using leaded ammunition, unleaded ammunition and modified unleaded ammunition. Gaseous and particulate emissions were monitored within the tent. The symptoms experienced by the subjects were recorded immediately after and the day after firing using a standardized questionnaire. The concentrations of particulate matter and copper exceeded their respective occupational exposure limits (eight hours per day, five days a week) by a factor of 3 and 27, respectively. Of the 55 subjects, 54 reported general and respiratory symptoms. The total number of symptoms reported was significantly higher among shooters using unleaded ammunition as compared with the use of leaded and modified unleaded ammunition. Copper was the substance that had the highest concentration relative to its toxicity. Although the general symptoms were found to be consistent with the development of metal fume fever, the respiratory symptoms indicated an irritant effect of the airways different from that seen in metal fume fever. More symptoms were reported when unleaded ammunition was used compared with leaded and modified unleaded ammunition.

The role of callous/unemotional traits in mediating the association between animal abuse exposure and behavior problems among children exposed to intimate partner violence.

PubMed

McDonald, Shelby Elaine; Dmitrieva, Julia; Shin, Sunny; Hitti, Stephanie A; Graham-Bermann, Sandra A; Ascione, Frank R; Williams, James Herbert

2017-10-01

Children exposed to intimate partner violence are at increased risk for concomitant exposure to maltreatment of companion animals. There is emerging evidence that childhood exposure to maltreatment of companion animals is associated with psychopathology in childhood and adulthood. However, few studies have explored developmental factors that might help to explain pathways from animal maltreatment exposure to children's maladjustment. The present study addresses this gap in the literature by examining relations between children's exposure to animal maltreatment, callous/unemotional traits (i.e., callousness, uncaring traits, and unemotional traits), and externalizing and internalizing behavior problems. A sample of 291 ethnically diverse children (55% Latino or Hispanic) between the ages of 7 and 12 was recruited from community-based domestic violence services. A meditational path model indicated that child exposure to animal maltreatment was associated with callousness (β=0.14), which in turn was associated with greater internalizing (β=0.32) and externalizing problems (β=0.47). The effect of animal maltreatment exposure on externalizing problems was mediated through callousness. Results suggest that callous/unemotional traits are a potential mechanism through which childhood exposure to animal maltreatment influences subsequent behavior problems. Future research is needed to evaluate the extent to which exposure to animal maltreatment affects children's adjustment over time in the context of other co-occurring adverse childhood experiences. Copyright © 2017 Elsevier Ltd. All rights reserved.

Blending Model Output with satellite-based and in-situ observations to produce high-resolution estimates of population exposure to wildfire smoke

NASA Astrophysics Data System (ADS)

Lassman, William

In the western US, emissions from wildfires and prescribed fire have been associated with degradation of regional air quality. Whereas atmospheric aerosol particles with aerodynamic diameters less than 2.5 mum (PM2.5) have known impacts on human health, there is uncertainty in how particle composition, concentrations, and exposure duration impact the associated health response. Due to changes in climate and land-management, wildfires have increased in frequency and severity, and this trend is expected to continue. Consequently, wildfires are expected to become an increasingly important source of PM2.5 in the western US. While composition and source of the aerosol is thought to be an important factor in the resulting human health-effects, this is currently not well-understood; therefore, there is a need to develop a quantitative understanding of wildfire-smoke-specific health effects. A necessary step in this process is to determine who was exposed to wildfire smoke, the concentration of the smoke during exposure, and the duration of the exposure. Three different tools are commonly used to assess exposure to wildfire smoke: in-situ measurements, satellite-based observations, and chemical-transport model (CTM) simulations, and each of these exposure-estimation tools have associated strengths and weakness. In this thesis, we investigate the utility of blending these tools together to produce highly accurate estimates of smoke exposure during the 2012 fire season in Washington for use in an epidemiological case study. For blending, we use a ridge regression model, as well as a geographically weighted ridge regression model. We evaluate the performance of the three individual exposure-estimate techniques and the two blended techniques using Leave-One-Out Cross-Validation. Due to the number of in-situ monitors present during this time period, we find that predictions based on in-situ monitors were more accurate for this particular fire season than the CTM simulations and satellite-based observations, so blending provided only marginal improvements above the in-situ observations. However, we show that in hypothetical cases with fewer surface monitors, the two blending techniques can produce substantial improvement over any of the individual tools.

Measuring the consequences of wildfires in a Bayesian network with vulnerability and exposure indicators

NASA Astrophysics Data System (ADS)

Papakosta, Panagiota; Botzler, Sebastian; Krug, Kai; Straub, Daniel

2013-04-01

Mediterranean climate type areas have always been experiencing fire events. However, population growth and expansion of urban centers into wildland areas during the 20th century (expansion of wildland-urban interface) has increased the threat to humans and their activities. Life and property losses, damage on infrastructure and crops, and forest degradation are some of the damages caused by wildfires. Although fires repeatedly occur along the Mediterranean basin, not all areas have experienced severe consequences. The extent of damage by wildfires is influenced by several factors, such as population density, vegetation type, topography, weather conditions and social preparedness [1]. Wildfire consequence estimation by means of vulnerability and exposure indicators is an essential part of wildfire risk analysis. Vulnerability indicators express the conditions that increase the susceptibility of a site to the impact of wildfires and exposure indicators describe the elements at risk [2],[3]. Appropriate indicators to measure wildfire vulnerability and exposure can vary with scale and site. The consequences can be classified into economic, social, environmental and safety, and they can be tangible (human life losses, buildings damaged) or intangible (damage of cultural heritage site). As a consequence, a variety of approaches exist and there is a lack of generalized unified easy-to-implement methodologies. In this study we present a methodology for measuring consequences of wildfires in a Mediterranean area in the mesoscale (1 km² spatial resolution). Vulnerability and exposure indicators covering all consequence levels are identified and their interrelations are stressed. Variables such as building materials, roofing type, and average building values are included in the economic vulnerability level. Safety exposure is expressed by population density, demographic structure, street density and distance to closest fire station. Environmental vulnerability of protected areas and rare species is also included. Presence of cultural heritage sites, power stations and power line network influence social exposure. The conceptual framework is demonstrated with a Bayesian Network (BN). The BN model incorporates empirical observation, physical models and expert knowledge; it can also explicitly account for uncertainty in the indicators. The proposed model is applied to the island of Cyprus. Maps support the demonstration of results. [1] Keeley, J.E.; Bond, W.J.; Bradstock, R.A.; Pausas, J.G.; Rundel, P.W. (2012): Fire in Mediterranean ecosystems: ecology, evolution and management. Cambridge University Press, New York, USA. [2] UN/ISDR (International Strategy for Disaster Reduction (2004): Living with Risk: A Global Review of Disaster Reduction Initiatives, Geneva, UN Publications. [3] Birkmann, J. (2006): Measuring vulnerability to natural hazards: towards disaster resilient societies. United Nations University Press, Tokyo, Japan.