A cross-sectional study of determinants of indoor environmental exposures in households with and without chronic exposure to biomass fuel smoke

Abstract

BackgroundBurning biomass fuels indoors for cooking is associated with high concentrations of particulate matter (PM) and carbon monoxide (CO). More efficient biomass-burning stoves and chimneys for ventilation have been proposed as solutions to reduce indoor pollution. We sought to quantify indoor PM and CO exposures in urban and rural households and determine factors associated with higher exposures. A secondary objective was to identify chronic vs. acute changes in cardiopulmonary biomarkers associated with exposure to biomass smoke.MethodsWe conducted a census survey followed by a cross-sectional study of indoor environmental exposures and cardiopulmonary biomarkers in the main household cook in Puno, Peru. We measured 24-hour indoor PM and CO concentrations in 86 households. We also measured PM2.5 and PM10 concentrations gravimetrically for 24 hours in urban households and during cook times in rural households, and generated a calibration equation using PM2.5 measurements.ResultsIn a census of 4903 households, 93% vs. 16% of rural vs. urban households used an open-fire stove; 22% of rural households had a homemade chimney; and <3% of rural households participated in a national program encouraging installation of a chimney. Median 24-hour indoor PM2.5 and CO concentrations were 130 vs. 22 μg/m3 and 5.8 vs. 0.4 ppm (all p<0.001) in rural vs. urban households. Having a chimney did not significantly reduce median concentrations in 24-hour indoor PM2.5 (119 vs. 137 μg/m3; p=0.40) or CO (4.6 vs. 7.2 ppm; p=0.23) among rural households with and without chimneys. Having a chimney did not significantly reduce median cook-time PM2.5 (360 vs. 298 μg/m3, p=0.45) or cook-time CO concentrations (15.2 vs. 9.4 ppm, p=0.23). Having a thatched roof (p=0.007) and hours spent cooking (p=0.02) were associated with higher 24-hour average PM concentrations. Rural participants had higher median exhaled CO (10 vs. 6 ppm; p=0.01) and exhaled carboxyhemoglobin (1.6% vs. 1.0%; p=0.04) than urban participants.ConclusionsIndoor air concentrations associated with biomass smoke were six-fold greater in rural vs. urban households. Having a homemade chimney did not reduce environmental exposures significantly. Measures of exhaled CO provide useful cardiopulmonary biomarkers for chronic exposure to biomass smoke.

Lack of association between chronic exposure to biomass fuel smoke and markers of right ventricular pressure overload at high altitude

“…Moreover, the median indoor 24-hour PM 2.5 -equivalent concentrations were similar in magnitude to values reported in other studies in Guatemala and China [44, 45]. Maximum concentrations of biomass fuel smoke during cooking in rural households, however, can exceed 1000 μg/m 3 [23], a gross environmental exposure by any standard. Third, we do not have information on personal exposure concentrations; however, we sought to compare to subpopulations with distinct levels of exposure and our indoor measurements supported this claim.…”

“…We also obtained a subsample of gravimetric measurements of PM 2.5 concentrations concurrently using the DataRAM pDR-1000 fitted with the PCXR4 universal sampling pump (SKC Inc., Eighty Four, PA) set to a flow rate of 4 L/min. We then applied a locally-derived correction factor to relative-humidity adjusted PM to calculate PM 2.5 -equivalent concentrations [23]. Indoor CO was measured using the EasyLog USB CO Monitor (Lascar Electronics, Erie, PA) over a 24-hour period.…”

“…Indoor CO was measured using the EasyLog USB CO Monitor (Lascar Electronics, Erie, PA) over a 24-hour period. We also measured outdoor PM 2.5 concentrations between March 2011 and November 2011 as previously explained [23]. …”

Developmental Effects Determine Submaximal Arterial Oxygen Saturation in Peruvian Quechua

“…A recent report showed higher FVC values in Lima subjects, compared to individuals from lowland rural towns, even if these rural towns had lower levels of pollution than Lima (Robinson et al, 2011). Moreover, even if air pollution tends to be higher in urban settings, highlanders could also be exposed to household air pollution, given the common practice of burning biomass fuel to cook in Andean towns (Pollard et al, 2014).…”

Caregiver perception of sleep-disordered breathing-associated symptoms in children of rural Andean communities above 4000 masl with chronic exposure to biomass fuel

“…In Peru, 93% of people residing in rural areas use biomassfueled stoves for cooking and heating, specifically solid fuel (wood and dung) [1]. Women have the highest level of exposure due to the time spent cooking and in other household activities, and, accordingly, young children also have a high level of exposure.…”