human health impacts of forest fires in the southern united … · 2013. 12. 8. · forest fires...

Vol. 7 2003 Fowler / Human Health Impacts of Forest Fires 39

Human Health Impacts of Forest Fires in the Southern UnitedStates: A Literature Review’

CYNTHLAT. FOWLER*

AbstractForestry management practices can shape patterns of health, illness, and disease. A primary goal for owners of

federal, state, andprivate forests is to crap ecosystem management plans that simultaneously optimize forest healthand human health. Fire-a majorforest management issue in the United States-complicates thesegoals. Wild-jres are naturalphenomena with unpredictable effects. Controlledf res, on the other band, are often prescribed toreduce biomass f;lreLs, reduce wikzj%-e risks, andprotect resource values. Wbilejres can enhance the health of$re-adapted ecosystems, research on the human health impacts of smoke fFom fores t fn-es is somewhat equivocal. Thisartirle synthesizes 30 years of research on the human health impacts offores t fzres. It summarizes our current stateof knowledge about the following: biopbysical efects of environmental contamination resuLtingj+om forestjres;

psycbosocia L impacts offorestjres; occupationalexposure issues amongjre crew; visibility impairmentfiom forestjre smoke; and health care measures that address the impacts offorestfzres. This articleprovides information thatmay be usefil for Land managers, researchers, policy makers, health care workers, and the general public indecision-making aboutforest managementpractices. It alro recommends tbat&ture research use integrative healthmode.h and adopt ethnographic research methods.

Fire Research in the SouthForestry management practices can shape pat-

terns of health, illness, and disease. A primary goalfor federal, state, and private foresters is to craft eco-system management plans that simultaneously opti-mize forest health and human health. Fire compli-cates these goals. Fire is a major forest managementissue in the United States because of its frequencyand its potential to damage natural and human re-sources. Wildfires are natural phenomena with un-predictable effects that occur across the continent atvarying rates. Controlled fires, on the other hand,are often prescribed to reduce biomass fuels, reducewildfire risks, and protect resource values. It is com-mon for people who own forests in fire-adapted eco-systems to use prescribed (or controlled) burning asa means for creating healthy forest ecosystems. Manyecosystems in the southern United States are fire-

adapted; for example, evergreen shrub bogs, sand-pine scrub, and flatwoods on the Coastal Plain; prai-rie grass savannas and pine forests in the Piedmont;and Table Mountain pine (Pinuspungens) and pitchpine (IT rigida) forests in the southern Appalachians.

While fires can enhance the health of fire-adapted ecosystems, research on the human healthimpacts of smoke from forest fires is somewhatequivocal. The health risks of smoke are particu-larly relevant in the southern United States, the re-gion with the highest annual average prescribedburn area in the United States (Haines et al. 1998).Between 1985 and 1994, 424,119 hectares weresubmitted to prescribed fires (Haines et al. 1998).For most people in the South, smoke produced fromforest fires has very little or no health impact. How-ever, smoke is a very real concern for certain

’ The original review that provided the source of this article is part of a project to produce the hypertext Encyclopedia ofSouthern Fire Science, fLnded by the J oint Fire Sciences Program, and conducted by USDA Forest Service researchers.

2 USDA Forest Service, Athens, Georgia.

40 Journal of Ecological Anthropology Vol.7 2003

segments of the population. Young children, theelderly, people with pre-existing cardiopulmonaryand psychiatric conditions, and smokers are par-ticularly vulnerable to smoke-related health risks.People at greater risk of exposure to smoke fromforest fires, for example residents of wildland-ur-ban interfaces, outdoor enthusiasts, and firefighters,are also more vulnerable to health risks.

This article synthesizes 30 years of research onthe human health impacts of forest fires. Researchon this topic is taking place in a variety of disciplinesincluding forestry, pulmonary medicine, epidemiol-ogy, public health, clinical and animal toxicology,sociology, and anthropology. Epidemiologic studieson the health consequences of indoor air pollutioncreated by the burning of biomass fuel for cooking,heating and light offer insight into the health im-pacts of biomass smoke created by forest fires (Larsonand Koenig 1994). Studies in the field of animal toxi-cology provide information about the impacts of bio-mass smoke on the health of animals that can beextrapolated with caution to expand our knowledgeofhuman health impacts. In animal toxicology stud-ies of the effects of the smoke from burning pine ondogs, researchers observed changes in epithelial cellsthat predict the development of pulmonary hyper-tension which increases heart attack risks (Larson andKoenig 1994). D amages to tracheobronchial epithe-ha1 cells appear in rabbits that breathe smoke fromburning white pine (Larson and Koenig 1994). En-zymatic changes predicting the development of pul-monary hypertension occurred in dogs that wereforced to breathe highly concentrated smoke fromburning pine (Larson and Koenig 1994). Significantchanges in macrophages occurred in rabbits that wereforced to breath smoke from burning Douglas fir(Larson and Koenig 1994). In the field of anthro-pology, researchers are interested in contemporaryburning practices of communities around the world(e.g., Vayda 1999). Anthropologists of Native NorthAmerica have reconstructed burning practices of pre-historic and early-historic communities within thecontext of overall ecological management regimes(e.g., Krech 1999). These are only a few examples ofresearch in a variety of disciplines that relates to theissue of the human health impacts of forest fires.

I have organized the research into the follow-ing sections for this literature review:

9 Health consequences of air pollutionl Health consequences of water contaminationl Psychosocial issuesl Occupational exposuresl Visibility impairment9 Health care measures

Variable Health ImpactsThere are many factors that prohibit our abil-

ity to make generalizations about the ways that peopleexperience forest fires. Variable factors such as firebehavior and fuel conditions-including types ofbio-mass and moisture levels in the soil-mediate thehuman health effects ofpollutants in biomass smoke.Fire intensity is another variable factor that influ-ences the composition of biomass smoke. In higherintensity fires carbon dioxide and water are the prin-ciple emissions. But, lower intensity fires character-ized by incomplete combustion, produce greatervolumes of harmful gases including carbon monox-ide, nitrogen oxides, sulfur oxides, hydrocarbons,polynuclear aromatic hydrocarbons, aldehydes, andfree radicals.

Human biological and cultural diversity resultin variable health impacts. Individual responses tobiomass smoke are conditioned by personal biophysi-cal histories (e.g., genotype), previous and currentexposures to pollutants, and variable coping strate-gies (American Thoracic Society 2000). Some seg-ments of the population present symptoms of smokeinhalation at dose-exposures that appear not to af-fect others or that have a very low impact on others(Evans and Campbell 1983; Therriault 200 1). Thegroups who are particularly vulnerable to biomasssmoke are young children, the elderly, people withpre-existing conditions, and smokers.

Weather also confounds relationships betweenbiomass smoke and human health. For instance, windpatterns disperse smoke from a combustion site inirregular ways thus producing spatial variability inhealth impacts. The southern United States has par-ticular meteorological traits (e.g., temperature, hu-midity) and ecological characteristics that dissuaderesearchers from using studies conducted in other


regions of the United States to design forest man-agement plans and to assess human health impacts.Seasonal weather differences may affect health out-comes in the South differently than in other regions(Schwartz 1994). In all regions of the United States,respiratory problems are most common during thewinter. In the South air pollution is at its worst dur-ing the summer while in the North air pollution isworse during the winter months. Some propose thatair pollution does not complicate winter respiratoryconditions in the South to the same degree as it doesin other regions (Schwartz 1994). Others argue thatregional differences in temperature and humidity donot affect patterns of respiratory illnesses associatedwith air pollution (Dockery and Pope 1994). Thisissue is one among numerous instances of the over-all uncertainty in the research literature about therelationships between smoke and human health.

It is difficult to make general assessments of thehealth risks from biomass smoke as a whole. Infor-mation about the relation between human health andsingle constituents of biomass smoke is more abun-dant in the scientific literature than informationabout the health effects ofsome combination of con-stituents. Knowledge of the combined effects (addi-tive, potentiated, and synergistic) of the multipleconstituents of biomass smoke is limited becausemost research to date examines the effects of singleconstituents. Yet, people experience biomass smokeas a complex mixture of chemical compounds ratherthan as isolated components. Even if scientific casestudies of the relation between human health andbiomass smoke from particular forest fires were plen-tiful, generalizations could only be made with cau-tion since the constituents of smoke and their rela-tive proportions vary from one fire to the next.

Health Consequences of Air PollutionIt is unclear whether the net effects of forest

fires to human health are adverse, beneficial, or in-consequential. Most investigations of this topic at-tempt to document adverse effects with little or noattention to beneficial effects. Yet, beneficial changesin interpersonal relations, and in socio-cultural, eco-nomic, and political systems can occur as a conse-quence of forest fires. Some researchers ask, “What

are the harmful effects of x constituent of biomasssmoke?” or “How didy fire impact the health of lo-cal people?” If they have not been able to demon-strate significant negative impacts, researchers con-clude that the effects of forest fires are inconsequen-tial. This section focuses on research that demon-strates the aduerse biophysical effects of biomasssmoke since the larger portion of researchers approachthe topic from this angle.

Forest fires produce biomass smoke containinga range of pollutants. Under some conditions and incertain concentrations, biomass smoke can adverselyaffect human health. Adverse effects of biomasssmoke are defined as medically significant or cultur-ally recognized psychosocial and biophysical changesin individual or population health (American Tho-racic Society 2000). At lower concentrations smokemay not directly threaten biophysical health, but cannevertheless be a “nuisance” (Machlis 2002).

Inhalation, ingestion, and dermal absorptionare the routes of exposure to smoke pollutants. In-halation is the most common pathway through whichhumans absorb constituents of biomass smoke. Der-mal absorption might also occur through a person’ssurface cells. One substance that skin cells directlyabsorb is free radicals that may contribute to the de-velopment of emphysema, Adult/Acute RespiratoryDistress Syndrome (ARDS), and lung cancer (Dost199 1). Gastrointestinal absorption is another path-way of exposure to the pollutants emitted by forestfires. Gastrointestinal absorption can occur throughthe ingestion of products such as plants that haveabsorbed pollutants through the soil or ash, wildlife+L,e. L,.,- ;..l.,I,A -.. :..,.-“*.A --ll..*--*- ..-A f--LUlLLL IILL”C ‘.ll‘PlLU “ I IlqjLOLCU y”llul*‘lLa) dllU ,,c311-

water species such as fish that have absorbed or in-gested contaminated water.

Medically significant biophysical effects of bio-mass smoke include acute, subchronic, and chroniceffects on public health. The spectrum of adversephysiological effects ranges from temporary, relativelyminor eye, nose, and throat irritations, to persistentcardiopulmonary conditions, and less-commonly, topremature death. The most notable subset of bio-physical effects involves cardiopulmonary function-ing. It is clear that air pollution in general interfereswith heart and lung processes. Changes in heart and

42 Journal of EIcological Anthropology Vol. 7 2003

lung processes caused by biomass smoke as one spe-cific type of air pollution are not as clear. In the fol-lowing section, I discuss studies conducted on peoplewho were exposed to biomass smoke as well as stud-ies on the health effects of particular constituents ofsmoke. This research is helpful in our attempts toassess the cardiopulmonary effects of forest fires.

Cardiopulmonary Conditions Caused byBiomass Smoke

Respiratory conditions that result from inhala-tion of biomass smoke include temporary, perma-nent, and progressive respiratory dysfunction (Ameri-can Thoracic Society 2000). Long-term exposure tosmoke may increase risks of developing chronic ill-nesses such as cancer (Therriault 2001), and respira-tory and vascular disease (Goh et al. 1999; Tan et al.2000). The most notable cardiopulmonary problemsresulting from biomass smoke (Betchley et al. 1997;Kane and Alarie 1977; Patz et al. 2000; Tan et al.2000) are included in Table 1.

Table 1. The most notable cardiopulmonary

problems resulting from biomass smoke(Betchley et al. 1997; Kane and Alarie 1977;Patz et al. 2000; Tab et al. 2000).

Decline in lung functioningDecline in breathing rateBreathing discomfortEmphysemaAsthmaAllergiesBronchitisAnginaMyocardial infarction/heart attackPneumonia

Particulate MatterParticulate matter3 is one of the most signifi-

cant emissions from forest fires. Ninety percent ofparticulate matter in biomass smoke is PM,,, mean-ing that it is IO micrometers or smaller in diameter(EPA 1998; Ottmar 2001). Seventy to ninety per-cent of particulate matter in smoke is PM,.5, mean-ing that it is 2.5 microns or smaller in diameter.Particles that have a diameter larger than 5 mi-crometers penetrate the upper respiratory tract.Particles with a diameter of 5 micrometers or lesscan penetrate the lower respiratory tract and de-posit in the bronchioles and alveoli (Dockery andPope 1994).

People who inhale particulate matter presentrespiratory symptoms such as coughing, wheezing,excess phlegm production, lung inflammation, sys-temic inflammation in the body, discomfort frombreathing, and shortness of breath. Cough is the mostcommon respiratory symptom associated with ex-posure to ambient particulate matter (Dockery andPope 1994). The inhalation of particulate matte1causes asthma, upper and lower respiratory tract in-fections, COPD (chronic obstructive pulmonar)disease), and Ischemic Cardiomyopathy (Dost 199 1Eeden 200 1; Health Research Working Group 200 1Larson and Koenig 1994). There is also a possiblelink between particulate matter and cancer (Adamet al. 2002).

Particulate matter aggravates pre-existing illnesses including asthma and heart conditions. Peopllwho have pre-existing conditions respond to lowedosages and shorter durations of exposure to biomass smoke than those who do nor have pre-existin:conditions. New cases of pulmonary diseases emergwhen particulate matter occurs in the range of 10100 m/m3, while pre-existing cases were aggravate<by the occurrence of particulate matter in the rangof 20-40 m/m3 for PM,,, and 40-50 m/m3 for PM(Osterman and Brauer 2000).

3 Parriculace matter refers to particles that are present in the air. Particulate matter rakes the form ofsmoke, soot, dirt, dust, ar:liquid droplets. Some sources of particulare matter are agricultural tilling, automobiles, factories, and driving on dirt roadParticulate matter occurs in a range of sizes from coarse to fine. Fine particulate matter is especially threatening CO hum;health because it can enter rhe respiratory system. The abbreviation for particulate matter is PM. The numbers that occursubscript after PM refer to the size of particles. Thus, PM,,, refers to particulate matter chat is 2.5 microns or smaIlerdiameter.

Vol. 7 2003 Fowler / Human Health Impacts of Forest Fires 4 3

Some researchers document associations be-tween elevated concentrations of biomass smoke anddeclining lung function by measuring Forced ExpiredVolume in one second (FEV,), Forced Expired Vol-ume in three-quarters of a second (FEV.,,), and forcedvital capacity (FVC) (Dockery and Pope 1994). In aseries of studies cited by Dockery and Pope (1994)lower respiratory symptoms increase 3.0% for each10 m/m3 increase in ambient PM,,. Lung functiondecreased by 0.15% as measured by FEV, and FEV.,swith each 10 m/m3increase in PM,,.

Acute biomass smoke pollution and exposureto particulate matter are associated with hematologicchanges in humans (Tan et al. 2000). The inhala-tion of biomass smoke reduces red blood cell levelsand damages cellular membranes as indicated by in-creases in albumin and lactose dehydrogenase anddepression of macrophage activity (Larson andKoenig 1994).

The deposition of PM,, and SO, in the respi-ratory system resulting from the inhalation of airpollutants stimulates bone marrow to release whiteblood cells. The bone marrow produces leukocytes,platelets, and proteins in response to the circulat-ing cytokines, promoting systemic inflammation inthe body, and contributing to the development ofcardiopulmonary disease (Eeden 2001). Cytokineproduction by alveolar macrophages in the lungsincreases in association with increases in PM,,(Eeden 2001) ’ dm icating an increase in PMN bandcells. Whereas PM,, immediately stimulates bonemarrow to release PMN band cells, the stimulationprovoked by SO, is delayed. PMN, polymorpho-nuclear leukocytes, are small white blood cells thatspecialize in phagocytosis, or the breaking down ofcells for defense.

IrritantsBiomass smoke and some of its constituents are

irritants. Smoke inhalation causes eye irritations andupper respiratory tract irritations. Symptoms fromacute exposure to organic acids, aldehydes (e.g., ac-rolein and formaldehyde), and respirable particulatematter include teary and burning eyes, runny nose,and scratchy and sore throat. Sulfur dioxide by itself

irritates the lungs and in combination with particu-late matter has even greater irritating effects (Evansand Campbell 1983). Acrolein is an irritant that cancause cellular toxicity in the upper respiratory tractand ciliary stasis (Dost I99 1). When forest fires burnin areas where the soil contains crystalline silica,smoke inhalation can cause silicosis, inflaming andscarring the lungs, thereby reducing oxygenation(Ottmar and Reinhardt 200 1).

The inhalation of numerous plant compoundscan cause skin and respiratory irritations. Some bo-tanical species that cause skin irritations in peoplewho have direct contacr with the whole plant cancause even worse reactions in people who inhale thesmoke that is emitted from the burning plant. Oneexample of this sort is poison ivy (Toxicodendronradicans). Other plants that do not necessarily causeadverse reactions in their whole, living form may havesevere consequences for people who inhale the smokefrom the burning plant. An example of this sort ismountain laurel (filmia spp.).

Carbon MonoxideCarbon monoxide is a major constituent of bio-

mass smoke. Inhalation of carbon monoxide increasesproduction of carboxyhemoglobin (COHb) above thebody’s normal amounts. Carboxyhemoglobin arebonds of carbon monoxide bonds and hemoglobinthat form when carbon monoxide displaces bloodoxygen. In excessive amounts, carboxyhemoglobincauses oxygen deprivation, damages body tissues, andinduces coughing and cold-like symptoms (Evans andCampbell 1983; Therriault 2001). Carboxyhemoglo-bin also complicates atherosclerosis and coronary heartdisease (Evans and Kantrowia 2002; Wad et al. 1989).

There is an association between biomass smokeand chest pain. In 1998, Floridians who were ex-posed to smoke from forest fires developed chest painand bronchitis (Patz et al. 2000). Ozone, a second-ary product of biomass combustion, causes chest painand other respiratory problems such as pulmonaryedema. Additional responses to ozone exposure in-clude headaches, and the aggravation of pre-existingasthma and pre-existing arrythmia (Evans andCampbell 1983; Patz et al. 2000).

44 Journal of Ecological Anthropology Vol. 7 2003

Documenting Associations Between Biomass

Smoke and Cardiopulmonary ConditionsResearchers have documented associations be-

tween elevated air pollution and decreases in pul-monary functioning indicated by reductions in FEVand FVC (Larson and Koenig 1994). For instance,decreases in FEV, and FEV,,, among school childrenin Steubenville, Ohio and the Netherlands are asso-ciated with increases in PM,, concentrations in theair (Dockery and Pope 1994). Asthmatic children inBirmingham experienced a decline in lung mnction-ing associated with increases in PM,,: their FEV, wastwo orders of magnitude more than non-asthmaticchildren (Schwartz et al. 1993).

Another method for investigating smoke-cardiopulmonary linkages is by conducting surveysof the use of medical facilities in communities nearforest fire events. These surveys demonstrate that hos-pital admissions and emergency room visits typicallyrise in communities that have been exposed to woodsmoke. Patients in these communities present gener-alized respiratory symptoms, acute bronchitis, chronicobstructive pulmonary disease, asthma, and chest pain(Mott 1999; Schwartz et al. 1993). Associations alsoexist between ozone increases and hospital admissions,as well as between daily mortality and increases inparticulate matrer. The association between acuteasthma and biomass smoke is not entirely consistent.A study in Australia found no increase in hospital ad-missions for acute asthma in association with bushfires(Cooper et al. 1994).

A survey by Mott (1999) found that, followinga 1999 wildfire on Hoopa Valley National IndianReservation, there was a 52% increase in visits tomedical care facilities by reservation residents. Sixtythree percent of interviewees in the study experiencedlower respiratory tract symptoms while the biomasssmoke was present. More than 20% of survey par-ticipants were still experiencing increased respiratorysymptoms two weeks after the smoke levels subsided.People who had pre-existing cardiopulmonary prob-lems (3 I .8% of the survey population) reported morerespiratory symptoms than those who did not havepre-existing conditions.

Children and the elderly appear to be particu-larly sensitive to biomass smoke. Hospital admissions

among the elderly for pneumonia and COPD in-crease in association with increases in PM,, (Schwartz1994). A study in Birmingham, Alabama docu-mented a lagged association of one day between in-creases in PM,, and increases in hospital admissionsof elderly people for pneumonia and COPD(Schwartz 1994). Children with and without pre-existing asthma conditions experience more respira-tory symptoms when ambient particulate matter andozone concentrations increase (Schwartz 1994). Fol-lowing exposure to air pollution caused by burningwood, children aged l-5 years old experience lungdysfunction sooner than people of other ages(Ostermann and Brauer 2000).

CarcinogenesisA number of the individual constituents of

forest fire smoke exhibit carcinogenic effects in clini-cal trials. The results of pure trials may be mislead-ing, though, since many substances covary with othersubstances and have emergent properties. An addi-tional complication is the difficultly of replicatingdose-exposures for individuals in a diverse popula-tion and for variable fire events (Evans and Campbell1983). A great deal of research has been conductedon the constituents of air pollution. A portion ofthis research focuses specifically on the constituentsof biomass smoke while other research concerns airpollution more generally. The following discussionof cancer-causing pollutants reviews literature ad-dressing biomass smoke in particular. But in somecases, the authors of this literature draw from researchon air pollution from sources other than forest fires.

The inhalation of air pollution containing par-ticulate matter may cause lung cancer (Ostermanand Brauer 2000). Inhalation of particulate mattercontaminated with dioxins may have carcinogeniceffects. For example, the dioxin TCDD-a compo-nent of an herbicide used in forestry management-sometimes occurs in biomass smoke (Mukerjee1997). Sarcoma, non-Hodgkin’s lymphoma, andliver cancer are associated with some of the tracegases that are present in biomass smoke includingdioxins and methyl bromide (Mukerjee 1997).Clinical trials associate nitrogen oxides with in-creased cancer rates (Adami et al. 2002). Ozone-

Vol. 7 2003 Fowler / Human Health Impacts of Forest Fires

produced from the hydrocarbons and nitrogen ox-ides emitted by fires-is carcinogenic.

Clinical trials have demonstrated the carcino-genic effects of over thirty polynuclear aromatic hy-drocarbons (PAHs) and hundreds of I’AH deriva-tives (Fang et al. 1999). High dose-exposures of somePAHs increase the risk of bladder cancer and lungcancer (Adami et al. 2002). Mhen present, formal-dehyde exacerb ta e s the carcinogenic effects of PAHs.Nasal and nasopharyngeal cancer may be a long-termeffect of formaldehyde inhalation (Therriault 200 I ;Ottmar and Reinhardt 2001). Formaldehyde maydecrease sensory capacity. Other aldehydes, elemen-tal carbon, and trace metals have potential carcino-genic effects (Partanen 1993). In small and infre-quent doses, however, aldehydes may not produce acarcinogenic effect (Dost 199 1). Aldehydes can alsocause contact dermatitis and uticaria (Dost 1991).An association between sulfates, which are commonlypresent in biomass smoke, and cancer has not beenestablished (Adami et al. 2002). Free radicals in for-est fire smoke react with tissues indicating that theyare carcinogenic and mutagenic.

Experimental field and laboratory burns showthat forest fires could increase the risk of human ex-posure to the radionuclides iodine- 129, cesium- 137,and chlorine-36 in areas contaminated with radio-active elements (Amiro et al. 1996). Human expo-sure may occur through inhalation of smoke con-taining radionuclides or ingestion of plants growingin soil and ash containing radionuclides. In thesecases, radionuclides can have immediate and/or de-layed carcinogenic effects for the exposed popula-tion. Some researchers speculate that the wildlandfire that burned through the Idaho National Engi-neering and Environmental Laboratory in 2000 mayhave exposed people in Idaho to harmful byproductsfrom the combustion of radioactive substances(Machlis 2002).

45

to cardiopulmonary dysfunction (Brauer 1999; Coreand Petersen 200 1; Dockery and Pope 1994). Peoplewho live in areas with high levels of ambient par-ticulate matter from biomass burning have reducedlife expectancy (Brauer 1999). Some of the measuresthat researchers use to investigate the associationbetween air pollution and morbidity and mortalityare hospital admissions, visits to emergency roomdepartments, visits to physician’s of&es, and use ofmedications such as bronchodilators for asthmatics(Dockery and Pope 1994). In addition, the reduc-tions in FEV,, FEV,,,5, and FVC that accompanyincreases in air pollution are predictors of prematuredeath (American Thoracic Society 2000).

Dockery and Pope (1994: 128) provide three ex-planations for the link between premature death andparticulate matter: 1) “acute bronchitis and bron-chiolitis may be misdiagnosed as pulmonary edema;”2) “air pollutants may increase lung permeability andprecipitate pulmonary edema in people with myo-car-dial damage and increased left atrial pressure;” and3) “bronchiolitis or pneumonia induced by air pol-lution, in the presence of pre-existing heart disease,might precipitate congestive heart failure.”

While the statistically significant links betweenair pollution and premature deaths due to cardiop-ulmonary problems are well documented, the de-tails of the causal links are difficult to explain.Dockery and Pope (1994) suggest that particulatematter is an additional environmental stressor thatpromotes premature death for vulnerable peopleand those who have pre-existing health problems.Particulate matter in urban and indoor air pollu-tion causes respiratory illness and disease leadingto premature death in infants, the elderly, andpeople with pre-existing cardiopulmonary disorders(Brauer 1999).

Premature DeathLoss of life may be an effect of biomass smoke

(Goh et al. 1999). Premature death is an acute andchronic effect of the inhalation of particulate matter(Patz et al. 2000). Research shows an associationbetween exposure to PM,, and premature death due

Acute exposure to carbon monoxide in doseshigh enough to dramatically reduce blood oxygen isdeadly (Therriault 200 1). Thus, carboxyhemoglobincan cause premature death. Carbon monoxide poi-soning may cause atheriosclerotic disease leading topremature death (Evans and Campbell 1983). Somestudies show that diseases result from interactions ofcarbon monoxide with nitrogen oxides and sulfuroxides (Evans and Campbell 1983). Most studies of


the association between particulate matter and pre-mature death eliminated sulfur dioxide as a con-founding pollutant (Fairley 1990; Pope et al. 1972).Other researchers suggest that long term exposuresto particulate matter and sulf;r dioxide emitted frombiomass burning is suspected of causing pulmonarylesions that result in premature deaths due to car-diopulmonary failure (Tan et al. 2000).

Numerous studies document an associationbetween abrupt, tremendous increases in particulatematter and increases in daily mortality, such as oc-curred in London in 1752 and in Donora, Pennsyl-vania in 1948 (Schwartz 1773). Acute exposure toless dramatic increases in PM,, have been associatedwith increases in mortality in Birmingham, Alabamaand eastern Tennessee, as well as in other regions ofthe United States (Schwartz 1773).

Dockery and Pope (1794) cite a set of studiesthat document a consistent correlation between in-creases in PM,, and increases in daily mortality. In astudy in Kingston, Tennessee researchers found thatfor each 10 m/m3 increase in PM,, there is a 1.6%change in daily mortality. In Birmingham, Alabamaresearchers documented a 1 .O% change in total dailymortality for each 10 m/m3 increase in PM,,; includ-ing a 1.5% change in respiratory mortality and a1.6% change in cardiovascular mortality. A laggedassociation appears in which daily mortality corre-lates to increases in PM,, between one and five daysprior to the day that the increases in mortality occur.Also notable in the studies cited by Dockery and Pope(1974) is the association between each 10 m/m3 in-crease in PM,, and an 0.8% rise in the numbers ofpatients admitted to hospitals and a 1 .O% rise in thenumber of patients who sought emergency care.There was a 3.4% increase for each 10 m/m3 increasein PM,, in asthmatic patients who sought emergencycare. Among asthmatics there was a 3% increase inboth asthmatic attacks and bronchodilator use.Deaths due to cancer and other non-cardiopulmo-nary issues were not associated with rises in PM,, inany of the studies cited by Dockery and Pope (1794).

Forest fires are also linked to deaths from heartattacks. In 1998 a firefighter from the Alabama For-estry Commission was constructing a fireline whenhe had a fatal heart attack. Three heart attack deaths

among the general public were connected to the 1978Florida forest fires (Wade 1978).

Other Adverse Health Effects of Biomass SmokeBiomass smoke is the source of several other

types of adverse health impacts. These include sup-pressed immunity, physical and cognitive impair-ments, and direct injury, Very little research has beenconducted on these topics, which is reflected in thebrief discussion that foil ows.

Suppressed Immunity

The inhalation of wood smoke decreases re-sistance to lung infections and increases suscepti-bility to respiratory infections by interfering withmacrophage phagocytosis (Brauer 19 77; Dost 19 9 1;Ward 1777). Aldehyd e s - n a m e l y a c r o l e i n - i nwood smoke inhibit the ability of scavenger cells inthe lungs to kill bacteria, thus increasing the possi-bility of respiratory infection (Ward 1779). The di-oxins that are sometimes present in forest fire smokeare immunosuppressants (Mukerjee 1797). Diox-ins increase susceptibility to infections (for exampleStaphylococcus aureus) by inhibiting humoral immu-nity and by affecting T-lymphocytes and B-lympho-cytes (Mukerjee 1777).

Physical and Cognitive ImpairmentsTrace gases in air pollution are associated with

weight loss, weakness, and fatigue. Carboxyhemo-globin, from breathing excessive amounts of carbonmonoxide, causes deficiency of blood oxygen lead-ing to slower reaction times, slower reflexes, drowsi-ness, disorientation, fatigue, diminished work capac-ity, reduced manual skills, and impaired mental abili-ties (Betchley et al. 1977; Evans and Campbell 1983).Inhalation of excessive amounts of carbon monox-ide reduces maximal aerobic capacity but not sub-maximal capacity in “young, healthy males” (Evansand Campbell 1983: 148). The physical discomfortsand psychological stress that accompany exposure toforest fire smoke may also be a causal factor in de-creased performance (Evans and Campbell 1983).Air pollution causes an assortment of other physicaland cognitive impairments including the following:inability to distinguish letters, colors, and brightness;


inability to calculate time intervals; and interferencewith peripheral vision and ability to respond toperipheral stimuli (Evans and Campbell 1983).

Direct h+ies

Forest fires cause an assortment of direct inju-ries (Patz et al. 2000). In the Baldwin Hills fire inLos Angeles, 12% of the community suffered burnsand other physical injuries due to exposure to thefire including one woman who had burns on morethan 60% of her body (Maida et al. 1989). An addi-tional 12% of people in the community experienceda fall due to the fire.

Health Consequences of Water ContaminationThe effects of forest fires on water quality vary

due to differing characteristics of the particular fireand the environment in which it occurs. Slope,ground cover, precipitation, and temperature all in-fluence the water quality changes that occur inburned areas. In addition, fire intensity and severity,and post-burn treatments affect water quality. Fireseverity-as a measurement of the amount of fuelsburned and nutrients released-is particularly influ-ential on water quality changes. The potential forerosion rises in association with fire severity: moresevere fires cause more dramatic changes in groundcover (Landsberg and Tiedemann 2000).

In some ecosystems, forest fires threaten wa-ter quality through several pathways. For instance,forest fires that burn riparian vegetation can increaseerosion that, in turn, can increase the frequency offlooding. As a result of erosion, excess sediment andnutrients (e.g., nitrates and nitrites) are deposited inwater sources (Landsberg and Tiedemann 2000).Thus, turbidity in streamflow often increases after aforest fire. Turbidity poses indirect threats to humanhealth by encouraging microbial production and in-creasing the risks of contracting infections for peoplewho come in contact with untreated water. Exces-sive amounts of sediment in a water supply may stressfiltration systems at water treatment facilities(Machlis 2002). Th e potential declines in water qual-ity that sometimes accompany forest fires pose risksto human health.

In addition to the erosion of sediment, the di-rect diffusion of biomass smoke into surface water isa source of nitrogen in water sources (Landsberg andTiedemann 2000). Similarly, excess phosphorouspartly results from the leaching of ashes that dropand dissolve directly in streamwater (Landsberg andTiedemann 2000). Mercury, a toxic metal that is apowerful neurotoxin (Tonnassen ZOOO), is sometimespresent in forest fire smoke and may be deposited inwater supplies. Human exposure to mercury canoccur through ingestion of freshwater species andwildlife as well as through the inhalation of biomasssmoke. It has been suggested that forest fires increasethe concentration of dissolved salts in drinking water,but this has not been adequately demonstrated (VanLear and Waldrop 1989).

In some situations, the exposure of surface wa-ters to sunlight may decrease, such as when biomasssmoke and haze block ultraviolet light (W-B). Therisk to human health occurs when a reduction inW-B is sufftcient enough to increase the growth ofbacteria and pathogens in water supplies (Malilay1979). In other situations, forest fires increase theexposure of surface waters to sunlight. Water tem-peratures may increase when fires burn off riparianvegetation exposing water sources to more direct sun-light. Eutrophication, affecting the “color, smell, andtaste of drinking water” (Landsberg and Tiedemann2000: 128), results from increased water temperatures(Arnaranthus and Arthur 1988).

Fire suppression and control techniques poten-tially damage water quality (Landsberg andTiedemann 2000; Norris and Webb 1988). For in-stance, the harmful chemicals (e.g., nitrates andammonia) that are found in the retardants and foamsthat are used in fire suppression may wash into wa-ter supplies. The construction of ftre breaks orfirelines may cause the erosion of nutrients into wa-ter supplies. Post-treatment techniques, such as theapplication of nitrate fertilizers to encourage the re-growth of vegetation, may increase the potential forhuman exposure to toxic substances that are washedinto drinking water supplies.

Relative to other forest management techniques,prescribed fires have less effect on water quality.

48 Journal of Ekological Anthropology Vol. 7 2003

Following a prescribed burn in a loblolly pine forestin the upper Piedmont of South Carolina, a 0.05parts per million (ppm) nitrate-nitrogen concentra-tion was measured in nearby water sources (Douglassand Van Lear 1983). Nitrate-nitrogen concentrationswere also found to be 0.05 ppm in the nearby watersources following post-treatment. Following post-burn treatments of a pine forest where a prescribedfire occurred in the coastal plain of South Carolina,0.02 ppm nitrate-nitrogen concentrations were mea-sured in water sources (Richter et al. 1982). Studiesfrom the Piedmont of Georgia demonstrated thatprescribed fire did not have a significant effect onsoil hydrology or suspended sediment concentrationsin streamflow (Van Lear and Waldrop 1989).

Some of the declines in water quality associ-ated with forest fires result from natural phenomenawhile others result from human actions. Soil erosion,sedimentation, diffusion, nutrification, and turbid-ity are consequences of forest fires. These conse-quences threaten human health by introducing bac-teria, pathogens, and toxins into drinking water sup-plies. To some degree these consequences cannot beprevented since wildfires are unpredictable and dif-ficult to control. Research shows that prescribed fireshave much less effect on water quality than wild-fires. Increasing the frequency of prescribed fires re-duces the frequency and severity of wildfires. Thus,one way to lessen the impact that forest fires have onwater quality is to increase the use of prescribed fires.

Up to this point, this article has discussed linksbetween forest fires, the environment, and humanhealth. The larger portion of research literaturefocuses on the biophysical effects of forest fires.Reports on studies of other types of health-namely,psychosocial health-outcomes are sparse. This isunfortunate since biophysical and psychologicalwellbeing are connected in multiple, complex ways.A more thorough understanding of the psychosocialimplications of forest fires would enable fire crews,medical personnel, and reliefworkers in governmen-tal and non-governmental agencies to better assistvictims of wildfires. In regard to prescribed fires, amore comprehensive biopsychosocial perspective(e.g., Jones et al. 2002; Zimmermann and Tansella1996) would also equip forest managers who imple-

ment prescribed fire with better tools for designingsuccessful education and public relations programs.

Psychosocial Consequences of Forest FiresHaving acknowledged the need for a more in-

tegrative model of human health and the paucity ofresearch on the psychosocial impacts of forest fires, Inow turn to the literature on the topic. Literaturethat focuses specifically on forest fires as well as re-search that addresses more generalized phenomenasuch as air pollution and natural disasters are in-cluded. This discussion is much more applicable tounderstanding the relationship between humanhealth and wildfires rather than prescribed fires.While I do mention several links between prescribedfires and psychosocial wellbeing, comparatively littleinformation is available on this topic.

Exposure to forest fires impacts psychosocialwell being in a variety of ways (Evans and Kan trowitz2002). The spectrum of medically significant psy-chosocial effects ranges from temporary frustration,to temporary or permanent reduction of health-related quality of life (HRQL), to post traumaticstress disorder (PTSD). Beneficial psychosocial con-sequences of forest fires include positive transforma-tions in interpersonal relations, financial profit, andcommunity cooperation.

Forest fires have different effects on differentcommunities: all communities do not respond toforest fires in exactly the same way. Likewise, forestfires have different effects on different individuals:within a community different individuals have different responses. Psychosocial effects may vary in as-sociation with the behavior and characteristics ofparticular forest fires. Psychosocial outcomes also varyaccording to an individual’s experiences, perceptions,interpretations, and coping mechanisms. Anindividual’s personal relationships and social contextshave a great influence on his/her attitudes and be-haviors related to forest fires. It is possible thatethnicity influences psychosocial symptoms andminorities may be more vulnerable to psychologicaldistress. For example, Mexican-American childrenwhen compared to children of any other ethnicgroups developed clinical PTSD following a fire di-saster investigated by Jones (2002).

Vol. 7 2003 Fowler / Human Health Imnacts of Forest Fires 49

So&o-cultural Trarzsjktmtions 1996). Forest fires affect future perceptions and de-Forest fires have been referred to as “engines of cisions related to self and community; for example,

change” (Force et al. 2000) in communities. In abroader context, natural disasters have spawned so-cial transformations monumental enough to be la-beled “cultural evolution” (Oliver-Smith 1996:3 12).

Oliver-Smith (1996:302) describes disasters as“challenges to the structure and organization of asociety. ” Forest fires may change community infra-structure (Machlis 2002). Interruptions in social ser-vices and damage to infrastructure cause individualand group stress (Oliver-Smith 1996). There maybe significant changes in social structure as a resultof forest fires. Individuals who experience a rise insocial status may benefit from forest fires; for instance,community members who successfully control partof a wildfire or firefighters who keep a fire from dam-aging local structures. Other members of the com-munity may not benefit from social changes. In somecommunities forest fires confer a negative imageupon, or stigmatize, a particular place, person, orsubgroup of the population (Machlis 2002).

Changes may occur in relations between com-munities and between cultural or ethnic groups (Gor-don et al. 1995). Relationships may change betweenindividual citizens, subgroups within a population,and between citizens and organizations (e.g., landand fire management teams). Social relationships andcommunication patterns within communities maychange during and after a forest fire (Machlis 2002).

Researchers have found that natural disasterschange political dynamics in communities (Oliver-Smith 1996). We might extrapolate from those stud-ies to suggest that catastrophic forest fires-as a typeof disaster--create conditions that encourage the re-organization of power relations, the formation of newalliances and agendas, and the emergence of activ-ism (Oliver-Smith 1996). The politics of represen-tation are a critical factor for communities experi-encing forest fires. The power to portray forest firesand to represent the communities who experiencefires influences perceptions held by insiders and out-siders to the community.

Natural disasters change the lived experiencesof individuals and have the power to transform self-identity and community identity (Oliver-Smith

perceptions of forest fire risks and decisions aboutlandscape management. Prescribed fires may posi-tively affect aesthetic values leading to greater satis-faction with one’s living environment. Severe wild-land fires that cause more dramatic transformations .of the landscape are more likely to be perceived asdetrimental.

Perceptions of forest fires may change follow-ing a fire. Direct experience with a forest fire causespeople to perceive that there is a higher risk of futurefires or to become more fearful of fire (Machlis 2002).In some cases, prescribed fires may be less acceptableto people who previously had direct experience withfires (Machlis 2002). In other cases, people who ex-perience a major fire near their home believe thatthe future possibility of another fire is very low(Cortner et al. 1990). If people live near fire-adaptedecosystems where fires “naturally” occur periodically,this belief may reflect a lack of knowledge about lo-cal fire regimes. Research shows that a forest fire canalter the future vulnerability and resiliency of a com-munity (Mach&s 2002) due to changes in ecosystemtraits, material infrastructure, cultural characteristics,and social relations.

Significant religious changes may follow majordisasters such as wildfires. Forest fires can also insti-gate changes in cultural values. For instance, valuesregarding marriage may shift from a view of it as along-term commitment, to seeking marriage as animmediate means for gaining security (Oliver-Smith1996). Transformations in symbols and rituals oc-cur as a consequence of natural disasters (Oliver-Smith 1996). Peop 1 e may mourn for the symbols ofself and community that are damaged or destroyedby natural disasters such as forest fires.

Grief and Distress

People exposed to forest fires may experiencegrief. Property loss, such as the destruction of ahome or damage to personal goods, can be a sourceof grief. Feelings of helplessness may arise amongpeople whose lives and property are threatened bywildland fires (Machlis 2002). Research on effectsof natural disasters in general shows that damages


to meaningful places, such as homes, evoke emo-tions of grief (Oliver-Smith 1996). It is likely thatpeople experience grief and a sense of loss whenforest fires damage meaningful locations, gather-ing places, and other public spaces. In some casesfire, like other types of natural disasters, may causethe disruption of social contexts which is also asource of grief (Oliver-Smith 1996).

Air pollution is a source of psychologicaldistress. Ozone-a component of air pollution-is associated with negative emotions and aggressivebehaviors (Evans and Kantrowitz 2002). Studies showthat the bad odors that often accompany air pollu-tion episodes cause evaluative and cognitive deficien-cies as well as behavioral disorders (Rotton 1983).Sensory stress from malodor impairs cognitive andintellectual functioning by interfering with anindividual’s ability to complete complex proof read-ing tasks, but does not decrease abilities to completesimple arithmetic tasks (Rotton 1983). One of theways that sensory stress effects behavior is that whena person has little control, he/she becomes frustratedmore easily (Rotton 1983).

Stress DisordersForest fires potentially induce more profound

forms of stress and clinical illnesses (Jones 2002; Patzet al. 2000). For example, PTSD can occur amongpeople who live in areas that have been affected byfires. Following a fire in 1985, members of theBaldwin Hills community in Los Angeles exhibitedan array of post-traumatic stress symptoms (Maida1989). In the community as a whole, 36% of peopleexperienced PTSD symptoms. Among people whowitnessed the fire 67% had trouble sleeping com-pared to 20% of people in the community as a whole.The PTSD symptoms exhibited by witnesses to thefire and the proportions of that population who expe-rienced those symptoms include the following: 56%felt jumpy, 44 /00 avoided reminders of the fire, and33% had nightmares, dreams, and disturbing memo-ries (Maida 1989). Th ere was an increase in medicalcare and use of medication among witnesses to thefire. Most of the community members who lost prop-erty due to the fire exhibited symptoms of depres-sion, with the exception of people who had good

insurance and could replace their former home witha better, new home.

Destruction of ‘place’ is one of the traumas thatevokes PTSD symptoms (Oliver-Smith 1996). PTSDsymptoms emerge following dislocation. Similarly,the evacuations that occur when forest fires threatenhomes and businesses or when biomass smoke reachesunhealthy levels (Mutch 2002; Therriault 2001;Wade 1998) create psychological distress. Althoughit has not been demonstrated in scientific studies,we might hypothesize that some portion of the thou-sands of people who were evacuated from their com-munities in Florida during the severe wildfire seasonin 1998 experienced some degree of psychologicaldistress. Residents of Clancy, Montana who werebeing evacuated due to a forest fire experienced frus-tration, fatigue, stress, and panic (Machlis 2002).Other fire-related events that evoke PTSD symptomsin adults are threats to life, physical injury, and theinjury or death of a loved one (Jones 2002).

Responding to and Recoveringfiom DamagesAid organizations can help mitigate psychologi-

cal distress among people who have suffered inju-ries and loss due to forest fires. For example, ProjectRecovery provided emotional support for victimsof the Cerro Grande fire in Los Alamos (Machlis2002). On the other hand, the “strange people” indisaster relief organizations who enter a communityto deliver aid or repair damage can be a source ofstress for local residents (Oliver-Smith 1996). It ispossible that fire management crews, like aid orga-nizations, and the materials that they bring withthem, cause stress for residents of communities lo-cated near fire events. The sights and sounds ofequipment arriving to fight a fire may cause the re-currence of fear among people who have prior ex-periences with wildland fires (Machlis 2002). Onthe other hand, the influx of fire management crewsinto communities has the potential to generate rev-enue for the community as they purchase goods fromlocal stores and patronize local businesses. Commu-nities located near fire events may benefit from ex-panded employment opportunities created when firemanagement organizations move into an area andhire local people (Machlis 2002).

“Fire-adapted communities” (Burns 2003, per-sonal communication) may be a useful concept formeasuring a group’s level of fire preparedness andcapacity for coping with fires that do occur. Forestfires have the potential to galvanize or fragment com-munities. Cooperation among people can catalyze acommunity’s recovery from disasters (Oliver-Smith1996). For instance, joining together to rehabilitateland burned in a wildland fire had a healing effectfor residents of Los Alamos (Machlis 2002). Socialbonds may be strengthened among people who co-operate during a wildland fire and in preparation foror recovery from a wildland fire.

Communities who have low amounts of thekinds of capital (social, natural, and financial) usefulfor responding positively to fire events may have thehighest risk of being adversely affected by forest fires.Newer communities, such as developments in wild-land-urban interfaces composed of recent immi-grants, may have less capacity to adjust after a firebecause their social networks are less functional. Incontrast, ‘traditional’ types of communities withstrong, functional social networks may have morecapacity to recover from a fire event (Burns 2003).

Strong social networks can serve as support sys-tems helping individuals cope with the physical, psy-chological, and other effects of forest fires. On theother hand, weak or vulnerable social networks mightcreate additional stress. Often, community membersas well as local and extra-local organizations assistindividuals with treating physical injuries and repair-ing material damages. Assistance with psychologicalissues may be an explicit target of aid or it may occuras a byproduct of other forms of assistance. Psycho-logical issues are not, however, always recognized asa problem in need of attention.

To return to a previous point, it is crucial thatfire and medical personnel recognize the interdepen-dence of biophysical and psychosocial health. Psychol-ogy is a critical mediating factor for overall wellbeing.A finding that supports this proposition is that airpollution and malodorous air are associated with in-creases in depression and anxiety, and with increasesin hospital admissions for psychiatric problems(American Thoracic Society 2000). A person’s psycho-lo&al condition can cause the biophvsical effects of

fire to be more or less severe (Evans and Campbell1983). In the reverse flow of causality, a person maydevelop psychological problems such as depression oranxiety as a result of physical problems caused by for-est fires (Evans and Campbell 1983).

Forest fires affect psychosocial health in multipleways on both individual and community levels. Cur-rent research illustrates that forest fires have the powerto transform a person or a community in ways thatare beneficial and/or detrimental. Sometimes thechanges are subtle and other times they are moreevident. The spatial and temporal effects of forestfires can be far reaching, but they tend to be espe-cially relevant for people located close to the placewhere burning occurs. Up to this point, discussionhas focused on the ways that forest fires impact thegeneral public; more specifically those members ofthe general public who are directly exposed to fire.The next section focuses on a special segment of thepopulation whom researchers have studied more thanany other community: fire workers.

Occupational Exposures

”

The experiences of fire workers differ from thoseof the general public. Two occupational factors thatmake fire workers a unique subgroup are their prox-imity to fire events and their dose-exposures to emis-sions from forest fires. An additional physiologicalfactor that differentiates this group is that fire work-ers tend to be relatively physically fit. The generalpublic and fire workers have similar responses to for-est fires, but their dose-exposure patterns differ.Among the general public, adverse health effects ap-pear in briefer time periods and at lower dosages(Brauer 1999; Ostermann and Brauer 2000).

Within the fire crew population, individualexposures differ according to the work practices ofthe particular firefighter (McMahon 1999), his/herlocation relative to the fire, and the amount of timehe/she spends at that location. At a prescribed burn,variability in exposure to pollutants occurs withina group according to each person’s particular du-ties. For instance, the “lighters” and “sawyers” havehigher benzene exposures due to the use of gaso-line in their drip torches and chainsaws. “Firelineholders” and “attack crew” have higher carbon


52 Journal of Ecological Anthropology vol. 7 2003

monoxide exposures due to their proximity to theflames and denser smoke.

Another work practice that varies amongfirefighters, influencing health risks, is shift duration.Wildland firefighters typically work shifts of eightto twelve hours or more. In some situations, wild-land firefighters are at or near a burn site over a pe-riod of days or weeks where, even during their off-shift time, they are exposed to biomass smoke (Ma-terna et al. 1992). In other situations, some portionof the work shift is spent in transit to and from thefire site and in other places some distance from thefire thus reducing the duration of a firefighter’s ex-posure to biomass smoke (Reinhardt et al. 2000).Firefighters may be exposed to unsafe levels of pol-lutants for punctuated time periods, but not neces-sarily continuously for an entire work shift.

Variations in meteorological patterns, includ-ing wind speed and direction, can produce variablehealth impacts. High wind speeds keep smoke in thebreathing zone of firefighters increasing their expo-sure to pollutants in biomass smoke (McMahon1999). In these cases, firefighters are more likely toexceed occupational limits for the inhalation of car-bon monoxide and respirable irritants such as par-ticulate matter, acrolein, and formaldehyde(McMahon 1999).

Air PollutantsIn general, fire workers experience acute,

subchronic, and chronic effects of exposure to forestfires. The acute exposures to respirable irritants thatfire workers sometimes experience can result in runnynoses, tearing eyes, stinging eyes and nose, and de-clines in lung function (Reinhardt et al. 2000). Astudy ofTime Weighted Average (TWA) particulatematter exposures among wildland firefighters docu-mented a high exposure of 37 mg/m3 with a meanexposure of 9.5 mg/m3 thereby exceeding the Occu-pational Safety and Health Administration-Permissable Exposure Limit (OSHA-PEL), whichlimits mean exposure to 15 mg/m3 (Materna et al.1999). A study of a “mop-up crew” at a forest firefound that 14% of exposures to total particulatematter exceeded the OSHA ceiling limit. Exposuresto PAHs and crystalline silica among this crew were

below OSHA-PELs. In some cases, the exposure offirefighters to PAHs may be consistent and long term,extending for several weeks while they are on duty(Rothman 1999). Ch ronic lung dysfunction amongfire workers can occur as a result of the cumulativeeffects of exposures to smoke over longer time spans(Liu et al. 1992).

Exposure to unsafe levels of carbon monoxidefrom burning vegetation can cause fire workers toexperience nausea, headaches, fatigue, impaired cog-nitive abilities, and reduced work capacity (Reinhardtet al. 2000). Research on fire worker exposures tocarbon monoxide is equivocal on the issue of dose-exposures. Some studies found that fire workers’ ex-posures to carbon monoxide during an 8-hour workshift did not exceed the OSHA-PEL of 35 ppm/hr(McMahon and Bush 1992). At wildfires, instanta-neous carbon monoxide exposures of fireline crewhave been measured to range from 3-80 ppm whichis below the OSHA ceiling limit of 200 ppm. Otherstudies suggest that fire workers may be exposed todangerous levels of carbon monoxide. For instance,a study of carbon monoxide concentrations near fireworkers downwind from a North Carolina fire mea-sured peak levels of carbon monoxide at 500 ppmwith average exposures at 75 ppm (Brauer 1999).Other studies of wildland firefighers documented arisk for exceeding 5% carboxyhemoglobin, the Na-tional Institute of Occupational Safety and Health(NIOSH) recommended limit (Materna et al. 1992).The carbon monoxide exposures among gasolinepump operators at forest fires can reach as high as300 ppm exceeding the OSHA ceiling limit (Ma-terna et al. 1992).

In the Pacific Northwest, researchers measured200 shift-exposures and burn-duration time-weighted-average exposures to pollutants amongprescribed fire crews over a period of 3 years(Reinhardt et al. 2000). The exposure measurementswere taken for a variety of fire workers includingthe “burn boss,” lighting crew, holding crew, hold-ing supervisor, attack crew, engine drivers and rid-ers, sawyer, and “mop-up crew.” Two percent of thegroup exceeded the American Council of Govern-mental and Industrial Hygienists-Threshold LimitValue (ACGIH-TLV) for carbon monoxide during


an eight-hour work shift. Eight percent exceededcarbon monoxide limits during a total burn(Reinhardt et al. 2000). For respirable irritants(formaldehyde, acrolein, and PM,,,), 14% of shift-average exposures and 30% of exposures for the to-tal burn exceeded ACGIH-TLVs. Thus, in somecases, firefighters may receive doses of particulatematter that are greater than OSHA-PELs (Liu etal. 1992).

Fire workers may be exposed to aldehydes atlevels that exceed OSHA-PELs (Liu et al. 1992).Aldehydes that have been detected in biomass smokeinclude formaldehyde, acetaldehyde, f&f&l, andacrolein. One study found that biomass smoke con-tains more formaldehyde than any other aldehydewhile another study found acrolein to be the mostabundant of the aldehydes (Materna et al. 1992).

Studies of wildland firefighters have docu-mented more adverse health effects of air pollutantscompared to those among firefighters at prescribedburns. At the 1988 Yellowstone Fires, firefighterssuckered declines in lung function indicated by de-creases in FEV, and increases in methcholine respon-siveness (Materna et al. 1992). Dust is the only airpollutant for which exposures among Yellowstonefirefighters exceeded N’IOSH occupational limits.

P3yc~ologicaC Stress093Wildland firefighters, like other emergency

workers, suffer numerous psychological stressors inaddition to physical stressors. Fox and Bowlus(1996:42) list the following causes of stress amongwildland firefighters: “line of duty death(s) or trau-matic injury, severely injured or dead infants andchildren, very close calls that are particularly lifethreatening or emotionally upsetting, an incidentattracting excessive media interest . . . a disaster . . .fire shelter deployment, burnovers, roll out of burn-ing debris, and falling dead trees (snags).”

Fifty percent of 333 wildland firefighters reportedexperiencing 12 out of 45 stress symptoms (Table 2)listed on a questionnaire in the survey administeredby Fox and Bowlus (1996). Table 3 includes strategiesused by wildland firefighters to cope with stress.

Table 2. Main psychological stress symptomsof wildland firefighters and the percentage ofrespondents who experienced the symptom

(Fox and Bowlus 1996).

76% Frustration69% Irritability63% Anger62% Sadness62% Sleep disturbances59% Mood swings56% Avoidance of feelings56% Loss of enthusiasm54% Fatigue56% Relationship problems53% Anxiety52% Depression

Table 3. Wildland firefighters’ coping strategies(Fox and Bowlus 1996:44-45).

91% “concentrate on other things”88% exercise88% “think about how things could have

been different if different actions wouldhave been taken by the individual”

87% “talk about the incident with coworkers”86% “talk with family and friends”86% “think about the humorous aspects of

the event”85% “try to be more helpful to others”

The gender of the fire worker influenced stressexperiences within the Fox and Bowlus (1996) surveypopulation, with women experiencing emotional andacute physical stress more oft-en than men. Ethnicityalso influenced stress with Native American firefightersexperiencing less stress than Caucasian and Asianfirefighters. There were no significant differences incoping strategies between age groups, between womenand men, or between ethnic groups.


Firefighter Safety Direct InjuGesFirefighters as an occupational group encoun- Firefighters sometimes become victims of un-

ter numerous injuries and deaths from a variety of predictable fire behavior. In 1999, two volunteer firecauses. Several programs and organizations have beenestablished to address firefighter safety. One exampleis the Fire Fighter Fatality and Investigation Programestablished by the National Institutes for Safety andHealth in 1998 to understand and prevent firefighterinjuries and deaths. Another example is the FederalFire and Aviation Safety Team who, together withthe National Interagency Fire Center, publishes “6Minutes to Safety” (http://www.nifc.gov/sixminutes/indexj.asp), a web-based program whose objectiveis to educate firefighters in the most up-to-date safetyinitiatives. The National Interagency Fire Centermaintains SAFENET (http://safenet.nifc.gov/), asystem whose objective is to ensure firefighter safetyby enabling all firefighters to report unsafe workingconditions. The National Wildfire CoordinatingG r o u p ( N W C G ) provides safety training forfirefighters and posts web-based safety alerts.

On the NWCG’s website (http://www.nwcg.gov/tearns/shwt/index2htm), is a list of firefighter injuriesand deaths from 1910-2002. Since 1910, 883firefighters have died while on duty (Table 4).

Table 4. Numbers of firefighter fatalities forsome of the main causes of accidents fkom191 O-2002 (source: National Wildfire Coor-dinating Group: http://www.nwcg.gov/teams/shwt/index2,htm).

Burnover 4 3 3Heart attack 93Aircraft accidents 4 7S n a g 32Helicopter accidents 30Airtanker accidents 25Engine rollover 22Burns 21Dozer burnover 16Electrocution 9

fighters died when they were overrun as they tried toflee upslope from a fire advancing through a hollow.A forest ranger died after receiving second and thirddegree burns over 60% of his body. He received burnswhile fleeing on foot from an advancing fire after ablade on his bulldozer got stuck in a tree.

Motor vehicle accidents cause deaths and inju-ries among both volunteer and career firefighters whoare traveling to or from fire sites. The most commoncauses of death for career firefighters are asphyxia-tion and traumatic injuries not related to motor ve-hicles. The most common causes of death for volun-teer fire fighters were asphyxiation and traumaticinjury from accidents involving motor vehicles.

Contact with electrical currents caused 10firefighter deaths between I980 and I999 accordingto the National Fire Protection Association. Someof the avenues through which fire fighters come intocontact with electrical currents are: downed powerlines; electrical currents transmitted through theground; water application tools charged with elec-trical currents; electrically charged equipment andgear; and electrical currents conducted by smoke.

Other Health EjlgctsDeaths from heart attacks occur during fires.

For example, in 1998 an Alabama Forestry Com-mission employee died of a heart attack while he wasconstructing a fireline (Wade 1998). In 2000, adriver/operator died from arrythmia brought on byatherosclerotic cardiovascular disease shortly afterclearing debris from a fireline as part of the USDAForest Service Wildland Fire Fighter “red card” cer-tification program.

In their research, Spear and Cannel1 (2002)found that, among mixmasters whom they surveyed,exposures to respirable dust, dyes, and hydrogen cya-nide in retardants never exceeded the limits dictatedby ACGIH-TLV TWAs or OSHA-PEL TWAs.Mixmasters are the group of fire workers who pre-pare retardants that are used to control forest fires.Typcially, retardants are prepared by mixing waterinto powdered chemicals. Common fire suppressants

Vol. 7 2003 . Fowler / Human Health Impacts of Forest Fires 55

such as Fire-Trol GTS-R and Fire-Trol 300F con-tain potentially hazardous chemicals. These chemi-cals are effective fire suppressants, but are also po-tentially toxic to humans. Exposure to the ammo-nium sulfate in these retardants may cause“hypermotility, diarrhea, nausea, and vomiting fromingestion” (Sp ear and Cannel1 2002:66). Thediammonium phosphate in retardants may causedermatitis, emphysema, asthma attacks, and irrita-tions of the eyes, respiratory tract, and gastrointesti-nal tract. Long-term exposure to retardants may causeirritations to the eyes, skin, and respiratory tract.

Fire workers are exposed to variable levels ofherbicides. Some studies revealed that forest work-ers are exposed to toxins from herbicides that wereapplied to forests immediately prior to burning(Malilay 1999) . 0 ht er research demonstrated thatthe presence of herbicides from an application pre-ceding a forest fire was not detectable in smoke(Malilay 1999).

Gharabegian et al. (1985) investigated noise ex-posures among several groups of fire workers includ-ing “fire line/camp crews,” “helipad crews,” and“ground crews” at an airbase. 100% of helipad crewmembers, 100% of portable pump operators, and30% of those “hot shot crew” members who usedchain saws received noise doses during a I$-hourwork shift that exceeded OSHA allowable limits.However, among the fire line work group as a whole,only 10% of the members received a noise dose levelabove 100% of the OSHA allowable limits.

In sum, firefighters encounter unique healthrisks while performing their occupational duties.They are exposed to unusual concentrations of haz-ards and pollutants with atypical frequencies of ex-posure. Physical fitness, work practices, meteorology,and fire characteristics are some sources of variationin health outcomes among individual firefighters.Fortunately there are numerous safety programsand governmental regulations that minimize po-tential harmful consequences and protect thehealth of firefighters. Even though firefighters aretypically the population most at risk, governmen-tal agencies also maintain legal standards that pro-tect the health of the general public from poten-tially threatening actions of forest fires such as the

emission of air pollutants and the reduction ofvisibility on highways.

Visibility Impairment

The Environmental Protection Agency (EPA)considers visibility to be a matter of “public welfare”(EPA 1998). To protect public welfare, EPA has es-tablished primary and secondary National AmbientAir Quality Standards (NAAQS) with the goal ofmaintaining socially acceptable levels of visibility. TheInteragency Monitoring of Protected Visual Envi-ronments (IMPROVE), a coalition of EPA employ-ees and federal land managers, monitors and enforcescompliance with NAAQS. NAAQS applies to thefollowing six “criteria pollutants:” PM,, and PM,,(fine particulate matter), ozone, nitrogen dioxide,carbon monoxide, sulfur dioxide, and lead (Ameri-can Thoracic Society 2000). The American Councilof Governmental and Industrial Hygienists(ACGIH), the National Institute of OccupationalSafety and Health (NIOSH), and the OccupationalSafety and Health Administration (OSHA) are threeother organizations that maintain exposure limits andoccupational standards for the pollutants that occurin biomass smoke. State, tribal, and local laws alsocontribute to the regulation of “nuisance smoke,” acategory that includes the smog that limits visibility.Resource management organizations, timber com-panies, and private landowners cooperate with gov-ernmental agencies in fire and smoke managementactivities (Mutch 2002).

The degree of visibility reduction in any areadepends on the character and concentration of smokeemitted by a forest fire combined with meteorologi-cal factors such as humidity and wind patterns. Vis-ibility decreases as humidity rates increase becausemore water is available for particulate matter to ab-sorb which increases the ability of particulates to scat-ter light (EPA 1998). The high humidity that is typi-cally found in many parts of the South results inmore frequent nuisance smoke in this region than insome other regions of the United States. Achtemeier(2002:4 1) describes the complexity of the situationas follows: “Meterology, climate, and topographycombine with population density and fire frequencyto make nuisance smoke a chronic issue in the south.”

56 Journal of &ological Anthropology Vol. 7 2003

The principle connection between visibility andhuman health is that the reduction of visibility dueto forest fire smoke can cause highway motor-vehicleaccidents leading to injuries and fatalities (Goh et al.1999). Detailed statistics are not readily available forthe injuries and fatalities caused by visibility reduc-tion. Some information is available, however. Be-tween 1979 and 1988 there were more than 28deaths, 60 serious injuries, and many minor injurieson roadways in the southern United States due tolow visibility (Mobley 1990). In 2000, reduced vis-ibility on highways caused by forest fire smoke re-sulted in 5 automobile deaths in Florida and 5 auto-mobile deaths in Mississippi (Achtemeier 2002). InJune 2000, a 14mile section of Interstate 95 inFlorida was closed when forest fire smoke reducedvisibility to near zero and caused 5 traffic accidentsin one morning (Machlis 2002).

“Super fog” is an’ extremely dense combinationof smoke and water vapor that is emitted from smol-dering fires and the burning ofwet firels (Achtemeier2 0 0 2 ) . S u p e r f o g i s v e r y d a n g e r o u s w h e nmotorvehicle drivers encounter it along roadways. A2002 wildfire in south Florida produced super fogthat caused a pileup with several fatalities on Inter-state 75. Five people were killed and another 26people were injured on the Mississippi/Alabama bor-der in 2000 in an accident caused by super fog. Peoplewho encounter super fog while they are driving havea very difficult time navigating their vehicles becauseof the drastic reduction in visibility. Visibility candecrease to as little as three feet when super fog ispresent (Achtemeier 2002).

Another connection between visibility and hu-man health is that forest fire smoke reduces the aes-thetics of a vista which can have psychological con-sequences for people who value clear views. The cul-tural preference for scenic vistas that many Ameri-cans share is considered to be an Air Quality RelatedValue (AQRV) (Tonnassen 2000). The reductionsin visibility that sometimes accompany biomasssmoke can change the look of the landscape, typi-cally in ways that do not coincide with human pref-erences. People have more appreciation for the beautyof landscapes when their views are unobstructed bysmog (Machlis 2002).

Governmental regulations require fire person-nel to maintain air quality and visibility. Fire work-ers are specifically trained to manage smoke so thatthe general public encounters minimal amounts. Re-searchers in the USDA Forest Service and other fireagencies devote a great deal of attention to under-standing smoke and devising techniques to controlit during wildfires and prescribed fires. Unfortunately,there are cases like the ones mentioned above wherefire behavior, meteorology, and population patternsmake this very difficult if not impossible.

Health Care MeasuresWildfire control and suppression techniques

contribute to the reduction of human health costs.Prescribed fire practices are designed to produce mini-mal human health threats. The USDA Forest Ser-vice publishes smoke management guidelines thatinstruct land managers in the best ways to reducethe health costs of prescribed burns (Hardy et al.2001). Numerous techniques are available to landand fire managers for preventing and reducing thepotential for water pollution. For example, the BurnArea Emergency Rehabilitation (BAER) programincludes treatments to prevent or reduce sedimenta-tion of water sources in areas affected by wildfires(Landsberg and Tiedemann 2000). Workers at pre-scribed fires use techniques that protect water sup-plies including “limiting fire severity, avoiding burn-ing on steep slopes, and limiting burning on sandyor potentially water repellent soils” (Landsberg andTiedemann 2000: 126).

Despite the best efforts of fire workers, bio-mass smoke sometimes reaches unhealthy levels inpopulated areas. Outdoor gatherings and activitiesshould be curtailed during smoke episodes to de-crease exposures to air pollutants. Exercising out-doors should be avoided where there are high levelsof biomass smoke (Therriault 2001). Exercisers arevulnerable to higher doses of air pollutants becausethey tend to breathe through their mouth and toinhale faster and deeper bringing more pollutantsinto the lungs. Public health officials recommendthat people stay indoors during smoke episodeseither in clean air shelters or in homes with cleanair (Therriault 200 I).


Outdoor air pollution can penetrate indoor serious damages to public health, including chronicareas. To minimize indoor air pollution, avoid smok-ing tobacco and burning fossil fuels for heat, cook-ing, or light. A variety of air filters can be used toclean particulate matter and harmful gases from in-door air. One of the most effective home filters isthe air conditioner. High Efficiency Particulate(HEPA) filters, and portable and electronic air clean-ers are also recommended (Therriault 200 1).

In some cases, it is necessary to evacuate peoplewho live in an area where biomass smoke has reachedunhealthy levels. Evacuation reduces exposure toharmful air pollutants by moving people from siteswith high levels of pollution to locations with betterair quality. Evacuation is feasible for some membersof a community. But there may be socio-economicbarriers that hinder some members from evacuating,such as job responsibilities and economic limitations(Mott 1999).

People who experience adverse health effectsfrom air pollution seek care in hospital emergencyrooms and are sometimes admitted to hospitals forrespiratory (Patz et al. 2000) and other illnesses. Somepeople suffering from adverse consequences of bio-mass smoke seek care from private physicians.

One hypothetical method for reducing humanhealth risks is to extinguish wildfires (Brauer 1999).In reality it is not possible to extinguish all wildfiresand completely eliminate health risks. The completeelimination of forest fires as a source of air pollutionis not an option. It is possible, however, to minimizeair pollution and other health risks with appropriatemanagement techniques.

DiscussionOpinions on the health impacts of forest fires

are somewhat equivocal. Some researchers have foundevidence that biomass smoke is injurious (Grant1988), while others have found evidence that biom-ass smoke does not have significant adverse healtheffects (McMahon 1999; Van Lear and Waldrop1989). Some researchers argue that public health risksfrom biomass smoke are minimal because air pollu-tion stemming from forest fires rarely if ever exceedslimits set by governmental and non-governmentalagencies (McMahon 1999). Other authors argue that

disease and premature death, occur even when airpollution levels are below the limits set by govern-mental agencies (EPA 1998; Schwartz 1993).

Th e predominant view of fire ecologists andforest managers is that prescribed burning reduceslong-term net health costs by reducing the risks ofcatastrophic wildfires that could result in even greaterlevels of air pollution and have other injurious ef-fects. Fire ecologists promote prescribed burning asa technique for enhancing ecosystem health in fire-adapted areas that rely on periodic burnings. Manyfire ecologists also promote a “let it burn” policy forwildfires arguing against the expensive policies de-signed to suppress or eliminate unplanned wildlandfires. In this view, fire is regarded as beneficial forlong-term ecosystem health and human health.

The ambiguity in the research literature on thehealth impacts of smoke is due both to the lack ofand inherent difficulties with research on this topic.As previously mentioned, most research on smokeeffects investigates single constituents of smoke suchas aldehydes, PAHs, particulate matter, hydrocar-bons, inorganic gases, and trace gases. Much of thisresearch tests the effects of these pollutants on humanhealth from sources other than forest fires such asautomobiles and industrial production. Another de-ficiency of the research literature is that most stud-ies look at short-term health outcomes, while veryfew studies of the long-term health effects of expo-sure to biomass smoke exist. Despite these limita-tions, our understanding of biomass smoke is increas-ing due to a growing interest in this subject amongthe general public, within the scientific community,and among policy makers and land managers.

Research on this topic should continue in orderto fill some of the voids in existing knowledge. Thereis a need for more research that investigates indi-viduals and communities in areas where forest firesburn. These studies ought to consider smoke aspeople actually encounter it during forest fires; thatis, a whole, complex mixture of interacting chemi-cals and particles. Among the current literature,there is a striking lack of information about the per-ceptions of individuals. Future research on thehealth impacts of fire could be imnroved bv using

58 Journal of Ecoiogkd Anthropology Vol. 7 2003

ethnographic methods. Research would be much moretextured if it included accounts of the ways that indi-viduals interpret their experiences with forest fires.

Each facet of the health-fire relationship oughtto be contextualized in a particular fire event and aparticular environment. A theme that emerges fromthe literature reviewed in this article is the variabilityof health effects. Throughout the literature, research-ers state that the degree to which fires impact airquality, water quality, and thus human health, varydepending on the particular fire’s behavior, meteo-rological conditions, and human behavior. To be ac-curate, future research ought to coordinate the char-acteristics of particular fires with local environmen-tal traits, in addition to local human conditions.

The inseparability of human health and eco-system health in the context of forest fires is appar-ent in the research currently available. Yet, our presentunderstanding is somewhat reductionistic and givesdisproportionate attention to the physiological ef-fects of fire. A more holistic view of the health im-pacts of forest fires would investigate psychological,social, cultural, economic, and political consequencesas well. Future investigations should pay more at-tention to links between physiological and other typesof effects of forest fires on people (e.g., psychologi-cal, economic, cultural). A holistic presentation re-quires both scaling up by contextualizing biomedi-cal and chemical analyses and scaling down by add-ing fine-grained understandings of individuals’ livedexperiences. In sum, I suggest that in the future, re-searchers expand their methodological repertoire anduse integrative models to better understand relation-ships between people and fire.

References CitedACHTEMEIER , G.L.

2002 “Super fog: A combination of smokeand water vapor that produces zerovisibility over roadways,” Paper pre-sented at the 12* Annual PollutionConference. Norfolk, VA. http://www.srs.fs.fed.us/disturbance/presentationweb/SuperFog2002PartI-files/frame.htm.

ADAM, H., D. HUNTER, AND D. TRICHOPOLJLOS.2002 Textbook of cancer epidemiology. Oxford:

Oxford University Press.AMARANTHUS, J., H. JUBA, AND D. ARTHUR.

1988 “Stream shading, summer streamflow,and maximum water temperaturefollowing intense wildfire in headwaterstreams,” in Proceedings of the Sympo-sium on Fire and Watershed Manage-ment, 26-28 October. Edited by N.Berg, pp. 75-78. Sacramento, CA:USDA Forest Service Pacific SouthwestForest and Range Experiment Station.

AMERUN THORACIC SOCIETY.2000 What constitutes an adverse health

effect of air pollution? American]ournalof Respiratory and Critical Care Medicine161:665-673.

AMIRO B.D., SC. SHEPPARD, EL. JOHNSTON, W.G.EVENDEN, AND D.R. HARRIS.

1996 Burning radionuclide question: Whathappens to iodine, cesium, and chlorinein biomass fires? The Science of the TotalEnvironment 187:93- 103.

BETCHLEY C., J. KOENIG, G. VAN BELLE, H.CHECKOWAY , AND T. REINHARDT .

1997 Pulmonary function and respiratorysymptoms in forest firefighters. Ameri-can journal of Industrial Medicine3 1:503-509.

BRAUER, M.1999 “Health impacts of biomass air pollu-

tion,” in Health guidelines for vegetationfire events - backgroundpapers. Editedby K.T. Goh, D. Schwela, J.G.Goldammer, and 0. Simpson, pp. 189-254. Singapore: World Health Organi-zation.

BURNS, S.2003 Group discussion held at “Humans,

Fire and Forests: Social Science Appliedto Fire Management.” Tucson, Arizona.

B. FASHEK, AND I? BOLTON.1994 Acute exacerbations of asthma and

bushfires. The Lancet 343(June11):1509.

CORE, J.E., AND J.L. PETERSEN.2001 “Air quality monitoring for smoke,”

in Smoke management guide forpre-scribed and wildlandjre. Edi ted byC.C. Hardy, R.D. Ottmar, J.L.Peterson, J.E. Core, and i? Seamon,pp. 179-185. Boise, ID: NationalWildfire Coordination Group, FireUse Working Team.

CORTNER, H.J., M.J. ZWOLINSKI, E.H. CARPENTER,AND J.G. TAYLOR.

1984 Public support for fire managementpolicies. Journal of Forestry82(6):359-361.

DOCKERY D.W., AND CA. POPE.1994 Acute respiratory effects of particulate

air pollution. Annual Reviews of PublicHealth 15:107-132.

DOST, EN.199 1 Acute toxicology of components of

vegetation smoke. Reviews of Environ-mental Contamination and Toxicology119:1-46.

DOIJGLASS, J.E., AND D.H. VAN LEAR.1983 Prescribed burning and water quality in

ephemeral streams in the Piedmont ofSouth Carolina. Forest Science49(1):181-189.

EEDEN, S.F.2001 Cytokines involved in the systemic

inflammatory response induced byexposure to particulate matter airpollutants (PM( 10)). American Journalof Respirato y and Critical Care Medicine

1998 “Fact sheet,” in The EnvironmentalProtection Agency; (EPA;) interim airquality policy on wildland andprescribed

fires. http://www.vistas-sesarm.org/documents/fire-ipfactsheetpdf.

EVANS, G.W., AND J.M. CAMPBELL.1983 Psychological perspectives on air pollu-

tion and health. Baric andAppliedSocial Psychology 4(2): 137- 169.

EVANS, G.W., AND E. KANTROWITZ.2002 Socioeconomic status and health: The

potential role of environmental riskexposure. Annual Review of PublicHealth 23~303-33 1.

FAIJUEY, D.1990 The relationships of daily mortality to

suspended particulates in Santa ClaraCounty 1980- 1986. EnvironmentalHealth Perspectives 89 : 15 9- 168.

FANG, M., M. ZHENG, F. WANG, K.L. To, A.B.JAAFAR, AND S.L. TONG.

1999 The solvent-extractable organic com-pounds in the Indonesia biomassburning aerosols - characterizationstudies. Atmospheric Environment33:783-795.

FORCE, J.E., G.E. ~CHLIS, AND L. ZHANG.2000 The engines of change in resource-

dependent communities. Forest Science46(3):410-421.

Fox, M., AND D. Bonus.1996 Critical incident stress effects on wild-

land firefighters. WiUj&e 1996(March):41-46.

GHARABEGIAN, A., KM. COSGROVE, J.R. PEHRSON,AND D.T. TRUNG.

1985 Forest fire fighters noise exposure.Noise Control Engineering Journal

164(5):826-830. 25(3):96-l 11.


COOPER C., M. MIRA, M. DANFORTH, K. ABRAHAM, EPA (ENVIRONMENTAL PRO?-ECUON AGENCY).

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