Outdoor and indoor fine particulate matter at skilled nursing facilities in the western United States during wildfire and non-wildfire seasons.

Wildfire activity is increasing in parts of the world where extreme drought and warming temperatures contribute to fireprone conditions, including the western United States. The elderly are among the most vulnerable, and those in long-term care with preexisting conditions have added risk for adverse health outcomes from wildfire smoke exposure. In this study, we report continuous co-located indoor and outdoor fine particulate matter (PM2.5 ) measurements at four skilled nursing facilities in the western United States. Throughout the year 2020, over 8000 h of data were collected, which amounted to approximately 300 days of indoor and outdoor sampling at each facility. The highest indoor 24 h average PM2.5 recorded at each facility was 43.6 µg/m3 , 103.2 µg/m3 , 35.4 µg/m3 , and 202.5 µg/m3 , and these peaks occurred during the wildfire season. The indoor-to-outdoor PM2.5 ratio and calculated infiltration efficiencies indicated high variation in the impact of wildfire events on Indoor Air Quality between the four facilities. Notably, infiltration efficiency ranged from 0.22 to 0.76 across the four facilities. We propose that this variability is evidence that PM2.5 infiltration may be impacted by modifiable building characteristics and human behavioral factors, and this should be addressed in future studies.

Case-fatality study of workers and residents with radiographic asbestos disease in Libby, Montana.

BACKGROUND: Vermiculite ore from Libby, Montana contains on average 24% of a mixture of toxic and carcinogenic amphibole asbestiform fibers. These comprise primarily winchite (84%), with smaller quantities of richterite (11%) and tremolite (6%), which are together referred to as Libby amphibole (LA). METHODS: A total of 1883 individuals who were occupationally and/or environmentally exposed to LA and were diagnosed with asbestos-related pleuropulmonary disease (ARPPD) following participation in communitywide screening programs supported by the Agency for Toxic Substances and Disease Registry (ATSDR) and followed up at the Center for Asbestos Related Disease (CARD) between 2000 and 2010. There were 203 deaths of patients with sufficient records and radiographs. Best clinical and radiologic evidence was used to determine the cause of death, which was compared with death certificates. RESULTS: Asbestos-related mortality was 55% (n = 112) in this series of 203 patients. Of the 203 deaths, 34 (17%) were from asbestos-related malignancy, 75 (37%) were from parenchymal asbestosis, often with pleural fibrosis, and 3 (1.5%) were from respiratory failure secondary to pleural thickening. CONCLUSIONS: Asbestos is the leading cause of mortality following both occupational and nonoccupational exposure to LA in those with asbestos-related disease.

Indoor fine particulate matter and demographic, household, and wood stove characteristics among rural US homes heated with wood fuel.

Household heating using wood stoves is common practice in many rural areas of the United States (US) and can lead to elevated concentrations of indoor fine particulate matter (PM2.5 ). We collected 6-day measures of indoor PM2.5 during the winter and evaluated household and stove-use characteristics in homes at three rural and diverse study sites. The median indoor PM2.5 concentration across all homes was 19 µg/m3 , with higher concentrations in Alaska (median = 30, minimum = 4, maximum = 200, n = 10) and Navajo Nation homes (median = 29, minimum = 3, maximum = 105, n = 23) compared with Montana homes (median = 16, minimum = 2, maximum = 139, n = 59). Households that had not cleaned the chimney within the past year had 65% higher geometric mean PM2.5 compared to those with chimney cleaned within 6 months (95% confidence interval [CI]: -1, 170). Based on a novel wood stove grading method, homes with low-quality and medium-quality stoves had substantially higher PM2.5 compared to homes with higher-quality stoves (186% higher [95% CI: 32, 519] and 161% higher; [95% CI:27, 434], respectively). Our findings highlight the need for, and complex nature of, regionally appropriate interventions to reduce indoor air pollution in rural wood-burning regions. Higher-quality stoves and behavioral practices such as regular chimney cleaning may help improve indoor air quality in such homes.

Growing from Our Roots: Strategies for Developing Culturally Grounded Health Promotion Interventions in American Indian, Alaska Native, and Native Hawaiian Communities.

Given the paucity of empirically based health promotion interventions designed by and for American Indian, Alaska Native, and Native Hawaiian (i.e., Native) communities, researchers and partnering communities have had to rely on the adaptation of evidence-based interventions (EBIs) designed for non-Native populations, a decidedly sub-optimal approach. Native communities have called for development of Indigenous health promotion programs in which their cultural worldviews and protocols are prioritized in the design, development, testing, and implementation. There is limited information regarding how Native communities and scholars have successfully collaborated to design and implement culturally based prevention efforts "from the ground up." Drawing on five diverse community-based Native health intervention studies, we describe strategies for designing and implementing culturally grounded models of health promotion developed in partnership with Native communities. Additionally, we highlight indigenist worldviews and protocols that undergird Native health interventions with an emphasis on the incorporation of (1) original instructions, (2) relational restoration, (3) narrative-[em]bodied transformation, and (4) indigenist community-based participatory research (ICBPR) processes. Finally, we demonstrate how culturally grounded interventions can improve population health when they prioritize local Indigenous knowledge and health-positive messages for individual to multi-level community interventions.

ERS/ATS workshop report on respiratory health effects of household air pollution.

Exposure to household air pollution (HAP) from solid fuel combustion affects almost half of the world population. Adverse respiratory outcomes such as respiratory infections, impaired lung growth and chronic obstructive pulmonary disease have been linked to HAP exposure. Solid fuel smoke is a heterogeneous mixture of various gases and particulates. Cell culture and animal studies with controlled exposure conditions and genetic homogeneity provide important insights into HAP mechanisms. Impaired bacterial phagocytosis in exposed human alveolar macrophages possibly mediates several HAP-related health effects. Lung pathological findings in HAP-exposed individuals demonstrate greater small airways fibrosis and less emphysema compared with cigarette smokers. Field studies using questionnaires, air pollution monitoring and/or biomarkers are needed to better establish human risks. Some, but not all, studies suggest that improving cookstove efficiency or venting emissions may be associated with reduced respiratory symptoms, lung function decline in women and severe pneumonia in children. Current studies focus on fuel switching, stove technology replacements or upgrades and air filter devices. Several governments have initiated major programmes to accelerate the upgrade from solid fuels to clean fuels, particularly liquid petroleum gas, which provides research opportunities for the respiratory health community.

Pulmonary abnormalities as a result of exposure to Libby amphibole during childhood and adolescence-The Pre-Adult Latency Study (PALS).

BACKGROUND: The purpose of Pre-Adult Latency Study was to evaluate lung findings among adults who had been environmentally exposed to Libby Amphibole only during childhood and adolescence. METHODS: Recruitment was restricted to volunteers who attended primary and/or secondary school, lived in Libby, MT, prior to age 23 years for males and 21 years for females and subsequently left the area. Subjects completed exposure and respiratory questionnaires, underwent pulmonary function tests (PFTs), and chest CT scans. A Pleural Score was calculated for degree and extent of pleural thickening. Logistic regression and multivariate linear regression were used. RESULTS: Of the 219 who met inclusion criteria, 198 participated. Pleural thickening was found in 96 (48%) of 198 participants. In almost half of these, it was of the lamellar type, not generally seen in exposure to other asbestos. Environmental Libby amphibole exposure was associated with pleural thickening, and the likelihood of pleural thickening increased with the number of years lived in the area. An inverse association between Pleural Score and PFT was found, which remained significant for FVC and DLco after additional sensitivity analyses. CONCLUSIONS: Cumulative environmental exposure was associated with risk of pleural thickening. Among this cohort, quantitative measures of pleural thickening were associated with decreased PFT. Am. J. Ind. Med. 60:20-34, 2017. © 2016 Wiley Periodicals, Inc.

A cross-sectional survey of occupational history as a wildland firefighter and health.

BACKGROUND: Little is known regarding the impact of long-term wildland firefighting on health. Our objective was to investigate associations between duration of wildland firefighting experience and the prevalence of self-reported health outcomes. METHODS: We ascertained employment, health, and demographic information on 499 current wildland firefighters (WLFFs) via questionnaire. RESULTS: Relative to those with less than 10 years of experience as a WLFF, those with 10-19 years of experience had significantly greater odds of having ever been diagnosed with hypertension, as did those with 20 or more years of experience. Significant associations were observed for report of physician-diagnosed heart arrhythmia and previous knee surgery. CONCLUSIONS: We observed significant links between a greater number of years as a WLFF and self-report of two subclinical cardiovascular risk factors as well as markers of musculoskeletal health. Additional studies are needed to determine if findings can be generalized to all WLFFs.

Indoor particulate matter in rural, wood stove heated homes.

Ambient particulate matter (PM) exposures have adverse impacts on public health, but research evaluating indoor PM concentrations in rural homes in the United States using wood as fuel for heating is limited. Our objectives were to characterize indoor PM mass and particle number concentrations (PNCs), quantify infiltration of outdoor PM into the indoor environment, and investigate potential predictors of concentrations and infiltration in 96 homes in the northwestern US and Alaska using wood stoves as the primary source of heating. During two forty-eight hour sampling periods during the pre-intervention winter of a randomized trial, we assessed PM mass (<2.5µm) and PNCs (particles/cm(3)) in six size fractions (0.30-0.49, 0.50-0.99, 1.00-2.49, 2.5-5.0, 5.0-10.0, 10.0+µm). Daily mean (sd) PM2.5 concentrations were 28.8 (28.5)µg/m(3) during the first sampling period and 29.1 (30.1)µg/m(3) during the second period. In repeated measures analyses, household income was inversely associated with PM2.5 and smaller size fraction PNCs, in particular. Time of day was a significant predictor of indoor and outdoor PM2.5 concentrations, and infiltration efficiency was relatively low (Finf (sd)=0.27 (0.20)). Our findings demonstrate relatively high mean PM concentrations in these wood burning homes and suggest potential targets for interventions for improving indoor air quality and health in rural settings.

Wildland firefighter work history and clinical indicators of cardiovascular health.

OBJECTIVE: To determine the association between the occupational history as a wildland firefighter (WFF) and clinical indicators of cardiovascular health. METHODS: Among 2,862 WFFs we evaluated associations between the number of total days assigned on fire and high-risk categories of three clinically measured cardiovascular indicators. RESULTS: Almost one-third (32%) of WFFs had one or more clinical measures that would place them in high-risk categories for BMI, blood pressure, and total cholesterol. WFF work history was associated with some of these measures: odds ratio (and 95% confidence interval) for highest versus lowest tertile of days on fire were 1.4 (1.2, 1.8) and 1.2 (1.0, 1.5) for high-risk categories of BMI and cholesterol, respectively. CONCLUSION: More frequent screening and targeted health promotion programs for WFFs are warranted to increase awareness of cardiovascular risk and prevention strategies.

Subclinical Measures of Cardiovascular Health Among Wildland Firefighters.

OBJECTIVE: The aim of the study is to compare subclinical measures of cardiovascular health among wildland firefighters (WFFs) to the US general population. METHODS: Our cross-sectional study compared body mass index, total cholesterol, and blood pressure in 11,051 WFFs aged 17 to 64 years using Department of the Interior Medical Screening Program clinical screening examinations between 2014-2018 to National Health and Nutrition Examination Survey of 2015-2016 cycle using adjusted logistic regression analyses. RESULTS: The logistic regression model shows significantly higher odds of hypertension and prehypertension in WFFs (2.84 times more with 95% CI: 2.28-3.53) than US general population. There were no consistent differences in body mass index or total cholesterol between the two population. CONCLUSIONS: Hypertension and prehypertension were more prevalent in WFFs compared with the US general population, which suggests the need for actions for protecting against cardiovascular disease among WFFs.

Managing multiple-casualty incidents: a rural medical preparedness training assessment.

OBJECTIVE: The objectives of this study were to develop a novel training model for using mass-casualty incident (MCI) scenarios that trained hospital and prehospital staff together using Microsoft Visio, images from Google Earth and icons representing first responders, equipment resources, local hospital emergency department bed capacity, and trauma victims. The authors also tested participants' knowledge in the areas of communications, incident command systems (ICS), and triage. METHODS: Participants attended Managing Multiple-Casualty Incidents (MCIs), a one-day training which offered pre- and post-tests, two one-hour functional exercises, and four distinct, one-hour didactic instructional periods. Two MCI functional exercises were conducted. The one-hour trainings focused on communications, National Incident Management Systems/Incident Command Systems (NIMS/ICS) and professional roles and responsibilities in NIMS and triage. The trainings were offered throughout communities in western Montana. First response resource inventories and general manpower statistics for fire, police, Emergency Medical Services (EMS), and emergency department hospital bed capacity were determined prior to MCI scenario construction. A test was given prior to and after the training activities. RESULTS: A total of 175 firefighters, EMS, law enforcement, hospital personnel or other first-responders completed the pre- and post-test. Firefighters produced higher baseline scores than all other disciplines during pre-test analysis. At the end of the training all disciplines demonstrated significantly higher scores on the post-test when compared with their respective baseline averages. Improvements in post-test scores were noted for participants from all disciplines and in all didactic areas: communications, NIMS/ICS, and triage. CONCLUSIONS: Mass-casualty incidents offer significant challenges for prehospital and emergency room workers. Fire, Police and EMS personnel must secure the scene, establish communications, define individuals' roles and responsibilities, allocate resources, triage patients, and assign transport priorities. After emergency department notification and in advance of arrival, emergency department personnel must assess available physical resources and availability and type of manpower, all while managing patients already under their care. Mass-casualty incident trainings should strengthen the key, individual elements essential to well-coordinated response such as communications, incident management system and triage. The practice scenarios should be matched to the specific resources of the community. The authors also believe that these trainings should be provided with all disciplines represented to eliminate training "silos," to allow for discussion of overlapping jurisdictional or organizational responsibilities, and to facilitate team building.

A rural community intervention targeting biomass combustion sources: effects on air quality and reporting of children's respiratory outcomes.

OBJECTIVE: Improvements in urban air quality are largely driven by controls on industrial and mobile source emissions, but such factors may have limited influence on many rural environments where biomass combustion (eg, wood stoves) serves as the primary source of fine particulate matter (PM(2.5)). The authors tracked changes in children's respiratory health during a wood stove intervention in a rural mountain valley community heavily impacted by wood smoke-derived PM(2.5). METHODS: Community-wide impacts on children's health were assessed by prospectively collecting surveys from parents of school children during four winter periods in Libby, Montana. Generalised estimating equations with a logit link were used to estimate the effect of reduction in ambient PM(2.5) on wheeze prevalence and other reported symptoms and infections. RESULTS: Over 1100 wood stoves were replaced with new lower emission wood stoves or other heating sources. Ambient PM(2.5) was 27.6% lower in the winters following the changeout programme compared with baseline winters. There was a 26.7% (95% CI 3.0% to 44.6%) reduced odds of reported wheeze for a 5 µg/m(3) decrease in average winter PM(2.5). Lower ambient PM(2.5) was also associated with reduced odds for reported respiratory infections, including cold (25.4% (95% CI 7.6% to 39.7%)), bronchitis (54.6% (95% CI 24.2% to 72.8%)), influenza (52.3% (95% CI 42.5% to 60.5%)) and throat infection (45.1% (95% CI 29.0% to 57.6%)). CONCLUSION: This wood stove intervention provided a unique opportunity to prospectively observe health benefits resulting from a targeted air pollution reduction strategy in a rural community.

Base camp personnel exposure to particulate matter during wildland fire suppression activities.

Wildland fire base camps commonly house thousands of support personnel for weeks at a time. The selection of the location of these base camps is largely a strategic decision that incorporates many factors, one of which is the potential impact of biomass smoke from the nearby fire event. Biomass smoke has many documented adverse health effects due, primarily, to high levels of fine particulate matter (PM(2.5)). Minimizing particulate matter exposure to potentially susceptible individuals working as support personnel in the base camp is vital. In addition to smoke from nearby wildland fires, base camp operations have the potential to generate particulate matter via vehicle emissions, dust, and generator use. We monitored particulate matter at three base camps during the fire season of 2009 in Washington, Oregon, and California. During the sampling events, 1-min time-weighted averages of PM(2.5) and particle counts from three size fractions (0.3-0.5 microns, 0.5-1.0 microns, and 1.0-2.5 microns) were measured. Results showed that all PM size fractions (as well as overall PM(2.5) concentrations) were higher during the overnight hours, a trend that was consistent at all camps. Our results provide evidence of camp-based, site-specific sources of PM(2.5) that could potentially exceed the contributions from the nearby wildfire. These exposures could adversely impact wildland firefighters who sleep in the camp, as well as the camp support personnel, who could include susceptible individuals. A better understanding of the sources and patterns of poor air quality within base camps would help to inform prevention strategies to reduce personnel exposures.

Efficacy of air filtration and education interventions on fine particulate matter among rural Native American homes heated with wood stoves: Results from the EldersAIR randomized trial.

BACKGROUND: Native Americans living in rural areas often rely upon wood stoves for home heating that can lead to elevated indoor concentrations of fine particulate matter (PM2.5). Wood stove use is associated with adverse health outcomes, which can be a particular risk in vulnerable populations including older adults. OBJECTIVES: We assessed the impact of portable air filtration units and educational approaches that incorporated elements of traditional knowledge on indoor and personal PM2.5 concentrations among rural, Native American elder households with wood stoves. METHODS: EldersAIR was a three-arm, pre-post randomized trial among rural households from the Navajo Nation and Nez Perce Tribe in the United States. We measured personal and indoor PM2.5 concentrations over 2-day sampling periods on up to four occasions across two consecutive winter seasons in elder participant homes. We assessed education and air filtration intervention efficacy using linear mixed models. RESULTS: Geometric mean indoor PM2.5 concentrations were 50.5 % lower (95 % confidence interval: -66.1, -27.8) in the air filtration arm versus placebo, with similar results for personal PM2.5. Indoor PM2.5 concentrations among education arm households were similar to placebo, although personal PM2.5 concentrations were 33.3 % lower for the education arm versus placebo (95 % confidence interval: -63.2, 21.1). SIGNIFICANCE: The strong partnership between academic and community partners helped facilitate a culturally acceptable approach to a clinical trial intervention within the study communities. Portable air filtration units can reduce indoor PM2.5 that originates from indoor wood stoves, and this finding was supported in this study. The educational intervention component was meaningful to the communities, but did not substantially impact indoor PM2.5 relative to placebo. However, there is evidence that the educational interventions reduced indoor PM2.5 in some subsets of the study households. More study is required to determine ways to optimize educational interventions within Native American communities.

Efficacy of Air Filtration and Education Interventions on Indoor Fine Particulate Matter and Child Lower Respiratory Tract Infections among Rural U.S. Homes Heated with Wood Stoves: Results from the KidsAIR Randomized Trial.

BACKGROUND: Millions of rural U.S. households are heated with wood stoves. Wood stove use can lead to high indoor concentrations of fine particulate matter [airborne particles ≤2.5µm in aerodynamic diameter (PM2.5)] and is associated with lower respiratory tract infection (LRTI) in children. OBJECTIVES: We assessed the impact of low-cost educational and air filtration interventions on childhood LRTI and indoor PM2.5 in rural U.S. homes with wood stoves. METHODS: The Kids Air Quality Interventions for Reducing Respiratory Infections (KidsAIR) study was a parallel three-arm (education, portable air filtration unit, control), post-only randomized trial in households from Alaska, Montana, and Navajo Nation (Arizona and New Mexico) with a wood stove and one or more children <5 years of age. We tracked LRTI cases for two consecutive winter seasons and measured indoor PM2.5 over a 6-d period during the first winter. We assessed results using two analytical frameworks: a) intervention efficacy on LRTI and PM2.5 (intent-to-treat), and b) association between PM2.5 and LRTI (exposure-response). RESULTS: There were 61 LRTI cases from 14,636 child-weeks of follow-up among 461 children. In the intent-to-treat analysis, children in the education arm [odds ratio (OR)=0.98; 95% confidence interval (CI): 0.35, 2.72] and the filtration arm (OR=1.23; 95% CI: 0.46, 3.32) had similar odds of LRTI vs. control. Geometric mean PM2.5 concentrations were similar to control in the education arm (11.77% higher; 95% CI: -16.57, 49.72) and air filtration arm (6.96% lower; 95% CI: -30.50, 24.55). In the exposure-response analysis, odds of LRTI were 1.45 times higher (95% CI: 1.02, 2.05) per interquartile range (25 µg/m3) increase in mean indoor PM2.5. DISCUSSION: We did not observe meaningful differences in LRTI or indoor PM2.5 in the air filtration or education arms compared with the control arm. Results from the exposure-response analysis provide further evidence that biomass air pollution adversely impacts childhood LRTI. Our results highlight the need for novel, effective intervention strategies in households heated with wood stoves. https://doi.org/10.1289/EHP9932.

Assessing the impact of a wood stove replacement program on air quality and children's health.

Many rural mountain valley communities experience elevated ambient levels of fine particulate matter (PM*) in the winter, because of contributions from residential wood-burning appliances and sustained temperature inversion periods during the cold season. A wood stove change-out program was implemented in a community heavily affected by wood-smoke-derived PM2.5 (PM < or = 2.5 microm in aerodynamic diameter). The objectives of this study were to evaluate the impact of this intervention program on ambient and indoor PM2.5 concentrations and to identify possible corresponding changes in the frequency of childhood respiratory symptoms and infections and illness-related school absences. Over 1100 old wood stoves were replaced with new EPA-certified wood stoves or other heating sources. Ambient PM2.5 concentrations were 30% lower in the winter after the changeout program, compared with baseline winters, which brought the community's ambient air within the PM2.5 standards of the U.S. Environmental Protection Agency (U.S. EPA). The installation of a new wood stove resulted in an overall reduction in indoor PM2.5 concentrations in a small sample of wood-burning homes, but the effects were highly variable across homes. Community-level reductions in wood-smoke-derived PM2.5 concentration were associated with decreased reports of childhood wheeze and of other childhood respiratory health conditions. The association was not limited to children living in homes with wood stoves nor does it appear to be limited to susceptible children (e.g., children with asthma). Community-level reductions in wood-smoke-derived PM2.5 concentration were also associated with lower illness-related school absences among older children, but this finding was not consistent across all age-groups. This community-level intervention provided a unique opportunity to prospectively observe exposure and outcome changes resulting from a targeted air pollution reduction strategy.

Carbon monoxide exposures in wildland firefighters in the United States and targets for exposure reduction.

BACKGROUND: Every year thousands of wildland firefighters (WFFs) work to suppress wildfires to protect public safety, health, and property. Although much effort has been put toward mitigating air pollutant exposures for the public and WFFs, the current burden in this worker population is unclear as are the most effective exposure reduction strategies. OBJECTIVE: Quantify fireline carbon monoxide (CO) exposures in WFFs and identify predictors of exposures. METHODS: We collected 1-min breathing zone CO measurements on 246 WFFs assigned to fires between 2015 and 2017. We used generalized estimating equations to evaluate predictors of CO exposure. RESULTS: Approximately 5% of WFFs had fireline CO exposure means exceeding the National Wildfire Coordinating Group's occupational exposure limit of 16 ppm. Relative to operational breaks, direct suppression-related job tasks were associated with 56% (95% CI: 47%, 65%) higher geometric mean CO concentrations, adjusted for incident type, crew type, and fire location. WFF perception of smoke exposure was a strong predictor of measured CO exposure. SIGNIFICANCE: Specific job tasks related to direct suppression and WFF perceptions of smoke exposure are potential opportunities for targeted interventions aimed at minimizing exposure to smoke.

Variability in childhood asthma and body mass index across Northern Plains American Indian communities.

OBJECTIVE: There are sparse data on the variability in childhood asthma across different Native American communities and the corresponding associations with known risk factors such as high body mass index and family history. The purpose of this study is to evaluate cross-sectional data on childhood asthma prevalence, body mass index, and other descriptive variables among Native Americans in five rural Northern Plains Indian reservation communities. METHODS: A school-based screening program was conducted on four Northern Plains Indian Reservations. The 1852 children (96% Native American, 4th through 12th grades) were screened for asthma status, body mass index (BMI), and family history. RESULTS: Approximately 9.5% of students reported current asthma. Current asthma varied significantly across the four reservation sites, ranging from 5.7% to 12.6%. Current asthma was also positively associated with BMI and family history of asthma. CONCLUSIONS: The intertribal differences in asthma prevalence noted here emphasize the need for further understanding the intertribal environmental, social, and behavioral factors that are associated with childhood asthma and obesity. Such knowledge can help inform disease prevention or disease management strategies that encompass the unique characteristics of tribal communities and culture.

Biomass smoke exposures: health outcomes measures and study design.

Epidemiological studies of biomass smoke health effects have been conducted in a variety of settings and with a variety of study designs. The Health Effects Workgroup discussed several approaches for the investigation of health effects in communities exposed to wood smoke from nearby wildland fires, intentional agricultural burning, or residential biomass burning devices such as woodstoves or cookstoves. This presentation briefly reviews observational and intervention studies that have been conducted within these exposure settings. The review is followed by a summary of discussion points among the workgroup members with particular emphasis on study design and the use of biomarkers for assessing outcomes in biomass smoke-exposed populations.