Size distribution and lung‐deposited doses of particulate matter from household exposure to biomass smoke

Exposure to high concentrations of particulate matter (PM) is associated with a number of adverse health effects. However, it is unclear which aspects of PM are most hazardous, and a better understanding of particle sizes and personal exposure is needed. We characterized particle size distribution (PSD) from biomass‐related pollution and assessed total and regional lung‐deposited doses using multiple‐path deposition modeling. Gravimetric measurements of kitchen and personal PM2.5 (< 2.5 µm in size) exposures were collected in 180 households in rural Puno, Peru. Direct‐reading measurements of number concentrations were collected in a subset of 20 kitchens for particles 0.3–25 µm, and the continuous PSD was derived using a nonlinear least‐squares method. Mean daily PM2.5 kitchen concentration and personal exposure was 1205±942 µg/m3 and 115±167 µg/m3 respectively, and the mean mass concentration consisted of a primary accumulation mode at 0.21 µm and a secondary coarse mode at 3.17 µm. Mean daily lung‐deposited surface area (LDSA) and LDSA during cooking were 1009.6±1469.8 µm2/cm3 and 10,552.5±8261.6 µm2/cm3, respectively. This study presents unique data regarding lung deposition of biomass smoke that could serve as a reference for future studies, and provides a novel, more biologically‐relevant metric for exposure‐response analysis compared to traditional size‐based metrics

Comparison of next-generation portable pollution monitors to measure exposure to PM2.5 from household air pollution in Puno, Peru.

Assessment of personal exposure to PM2.5 is critical for understanding intervention effectiveness and exposure-response relationships in household air pollution studies. In this pilot study, we compared PM2.5 concentrations obtained from two next-generation personal exposure monitors (the Enhanced Children MicroPEM or ECM; and the Ultrasonic Personal Air Sampler or UPAS) to those obtained with a traditional Triplex Cyclone and SKC Air Pump (a gravimetric cyclone/pump sampler). We co-located cyclone/pumps with an ECM and UPAS to obtain 24-hour kitchen concentrations and personal exposure measurements. We measured Spearmen correlations and evaluated agreement using the Bland-Altman method. We obtained 215 filters from 72 ECM and 71 UPAS co-locations. Overall, the ECM and the UPAS had similar correlation (ECM ρ = 0.91 vs UPAS ρ = 0.88) and agreement (ECM mean difference of 121.7 µg/m3 vs UPAS mean difference of 93.9 µg/m3 ) with overlapping confidence intervals when compared against the cyclone/pump. When adjusted for the limit of detection, agreement between the devices and the cyclone/pump was also similar for all samples (ECM mean difference of 68.8 µg/m3 vs UPAS mean difference of 65.4 µg/m3 ) and personal exposure samples (ECM mean difference of -3.8 µg/m3 vs UPAS mean difference of -12.9 µg/m3 ). Both the ECM and UPAS produced comparable measurements when compared against a cyclone/pump setup