The aims are to: 1) conduct the first randomized intervention trial in air pollution history, thus increasing confidence in air pollution risk estimates, which are currently based on observational studies; 2) estimate personal particulate (PM) exposures for children across a wide range of exposures associated with an improved stove (intervention) and the traditional open fire (control) thus potentially assisting efforts to understand the shape of the exposure-response curve of PM impact in young children. After a 7-year search and 14 pilot studies, an excellent site has been characterized in highland Guatemala where PM exposures are dominated by open wood-burning cookstoves producing daily 24-hours PM 2.5 exposure levels of 1000 ug/m3 and higher, i.e., some 60 times more than current United States standards. Such conditions are common in less-developed countries (LDCs), where some two-thirds of households rely on biomass fuels (wood, dung, crop residues). Pilot work has identified a socially and economically acceptable intervention, a chimney stove that is capable of reducing mean exposures by 6- 10x. The primary health outcome to be measured, acute lower respiratory infection (ALRI), is the chief cause of morbidity in children under 5 worldwide and the chief cause of death among LDC children. It thus accounts for nearly 10% of the entire burden of global disease, making it the single largest category of ill-health. The need to examine this relationship in more detail is highlighted by some dozen case-control or cohort studies in the United States and LDCs that have found significant odds ratios for ALRI in young children living in households using wood or other biomass fuels, suggesting that reducing this exposure to pollution may be a powerful preventive intervention. 500 children, allocated randomly to control and intervention groups, will be visited weekly from birth to 18 months to detect a 25% difference in ALRI incidence (power=0.8; alpha=5%). Diagnosis will be done using international protocols and physician verification. Child personal exposures and household microenvironments will be monitored twice each season (four times per year), and more intensely in a subsample. Because pilot studies consistently show passive CO diffusion tubes to be reliable indicators of PM arising from use of wood fuel, they will be used as the primary exposure monitors for the children. Total individual PM exposure will be modeled for each child using the information from the personal CO monitors, from microenvironmental PM and CO measurements in a subsample of households, and activity pattern information for each child. Previous pilot studies at the site have shown that exposures in the intervention and control groups will extend from PM levels similar to those found outdoors in United States cities, where most previous epidemiology has focused, to levels more than an order of magnitude higher. Active smoking risks provide evidence that the curve must become less steep at exposures much higher than ambient air pollution, but it is not known how the curve is shaped in the wide gap between, within which lie the exposures experienced by this study population. An important secondary objective therefore is to describe the relationship between exposure and ALRI incidence across this range. Neither the primary nor secondary aim is likely to be achieved in the United States or other developed country today, because the needed conditions have ceased to exist, i.e., exposures are not dominated by household sources suited to randomized intervention and also lie in a relatively limited range because they are heavily influenced by widespread outdoor sources. Thus, in addition to being directed toward a serious health problem in a large vulnerable population worldwide, this research can assist the worldwide inquiry into PM health effects by moving air pollution epidemiology closer to the strongest stage of the (Bradford) Hill criteria for establishing causality, the """"""""gold standard"""""""" of randomized intervention.

Agency
National Institute of Health (NIH)
Institute
National Institute of Environmental Health Sciences (NIEHS)
Type
Research Project (R01)
Project #
5R01ES010178-03
Application #
6635499
Study Section
Special Emphasis Panel (ZES1-LKB-C (RS))
Program Officer
Srinivasan, Shobha
Project Start
2001-06-01
Project End
2005-05-31
Budget Start
2003-06-01
Budget End
2004-05-31
Support Year
3
Fiscal Year
2003
Total Cost
$431,661
Indirect Cost
Name
University of California Berkeley
Department
Public Health & Prev Medicine
Type
Schools of Public Health
DUNS #
124726725
City
Berkeley
State
CA
Country
United States
Zip Code
94704
Guarnieri, Michael; Diaz, Esperanza; Pope, Daniel et al. (2015) Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Wood Smoke Exposure: Results From the Randomized Exposure Study of Pollution Indoors and Respiratory Effects and Chronic Respiratory Effects of Early Childhood Chest 148:1184-1192
Pope, Daniel; Diaz, Esperanza; Smith-Sivertsen, Tone et al. (2015) Exposure to household air pollution from wood combustion and association with respiratory symptoms and lung function in nonsmoking women: results from the RESPIRE trial, Guatemala. Environ Health Perspect 123:285-92
Thompson, Lisa M; Yousefi, Paul; PeƱaloza, ReneƩ et al. (2014) Genetic modification of the effect of maternal household air pollution exposure on birth weight in Guatemalan newborns. Reprod Toxicol 50:19-26
Guarnieri, Michael J; Diaz, Janet V; Basu, Chandreyi et al. (2014) Effects of woodsmoke exposure on airway inflammation in rural Guatemalan women. PLoS One 9:e88455
Long, Alexandra S; Lemieux, Christine L; Yousefi, Paul et al. (2014) Human urinary mutagenicity after wood smoke exposure during traditional temazcal use. Mutagenesis 29:367-77
Ruiz-Mercado, Ilse; Canuz, Eduardo; Walker, Joan L et al. (2013) Quantitative metrics of stove adoption using Stove Use Monitors (SUMs). Biomass Bioenergy 57:136-148
McCracken, John P; Schwartz, Joel; Diaz, Anaite et al. (2013) Longitudinal relationship between personal CO and personal PM2.5 among women cooking with woodfired cookstoves in Guatemala. PLoS One 8:e55670
Ruiz-Mercado, Ilse; Canuz, Eduardo; Smith, Kirk R (2012) Temperature dataloggers as stove use monitors (SUMs): Field methods and signal analysis. Biomass Bioenergy 47:459-468
Lam, Nicholas L; Chen, Yanju; Weyant, Cheryl et al. (2012) Household light makes global heat: high black carbon emissions from kerosene wick lamps. Environ Sci Technol 46:13531-8
Lam, Nick; Nicas, Mark; Ruiz-Mercado, Ilse et al. (2011) Non-invasive measurement of carbon monoxide burden in Guatemalan children and adults following wood-fired temazcal (sauna-bath) use. J Environ Monit 13:2172-81

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