State and national household concentrations of PM2.5 from solid cookfuel use: Results from measurements and modeling in India for estimation of the global burden of disease

Abstract

BackgroundPrevious global burden of disease (GBD) estimates for household air pollution (HAP) from solid cookfuel use were based on categorical indicators of exposure. Recent progress in GBD methodologies that use integrated–exposure–response (IER) curves for combustion particles required the development of models to quantitatively estimate average HAP levels experienced by large populations. Such models can also serve to inform public health intervention efforts. Thus, we developed a model to estimate national household concentrations of PM2.5 from solid cookfuel use in India, together with estimates for 29 states.MethodsWe monitored 24-hr household concentrations of PM2.5, in 617 rural households from 4 states in India on a cross-sectional basis between November 2004 and March 2005. We then, developed log-linear regression models that predict household concentrations as a function of multiple, independent household level variables available in national household surveys and generated national / state estimates using The Indian National Family and Health Survey (NFHS 2005).ResultsThe measured mean 24-hr concentration of PM2.5 in solid cookfuel using households ranged from 163 μg/m3 (95% CI: 143,183; median 106; IQR: 191) in the living area to 609 μg/m3 (95% CI: 547,671; median: 472; IQR: 734) in the kitchen area. Fuel type, kitchen type, ventilation, geographical location and cooking duration were found to be significant predictors of PM2.5 concentrations in the household model. k-fold cross validation showed a fair degree of correlation (r = 0.56) between modeled and measured values. Extrapolation of the household results by state to all solid cookfuel-using households in India, covered by NFHS 2005, resulted in a modeled estimate of 450 μg/m3 (95% CI: 318,640) and 113 μg/m3 (95% CI: 102,127) , for national average 24-hr PM2.5 concentrations in the kitchen and living areas respectively.ConclusionsThe model affords substantial improvement over commonly used exposure indicators such as “percent solid cookfuel use” in HAP disease burden assessments, by providing some of the first estimates of national average HAP levels experienced in India. Model estimates also add considerable strength of evidence for framing and implementation of intervention efforts at the state and national levels.

Millions Dead: How Do We Know and What Does It Mean? Methods Used in the Comparative Risk Assessment of Household Air Pollution

“…Separate estimates by sex were 2.30 (1.73, 2.06) for women and 1.90 (1.15, 3.13) for men. 3 Causal inference is supported by these findings, consistency (almost all studies reported increased risk, though not all significant), positive intervention-based findings (7), exposure-duration evidence, analogous evidence from smoking, and biological plausibility.…”

Profile of particulate-bound organic compounds in ambient environment of Srinagar: a high-altitude urban location in the North-Western Himalayas

“…The use of biomass fuel combustion in most of the Himalayan region is a significant part of the energy need, and its use escalates during winter season (Parikh 2011). Emissions from biomass and fossil fuel (PAHs and other organic compounds), and climate variables would impact the composition of OCs associated with ambient PM which may differ from that observed from other regions (Gelencsér 2004;Liu et al 2009;Balakrishnan et al 2013).…”

Lung Function in Rural Guatemalan Women Before and After a Chimney Stove Intervention to Reduce Wood Smoke Exposure

“…3 billion people worldwide continuing to use solid fuel for cooking or heating leading to dramatic indoor air pollution, with concentrations of particulate matter that are often 30 times higher than the air quality guidelines of the World Health Organization. 2,3 Although abundant epidemiologic evidence suggests that chronic biomass smoke exposure is associated with COPD, [4][5][6][7] results from stove trials have been less consistent. Although an intention-to-treat (ITT) analysis from the Randomized Exposure Study of Pollution Indoors and Respiratory Eff ects (RESPIRE) in Guatemala did not identify a difference in lung function decline in young adult women receiving a chimney stove compared with open fire users over 12 to 18 months of follow-up, 8 an exposure-response analysis showed that higher exhaled breath carbon monoxide (EB co ) was associated with lower FEV 1 .…”