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 mu m 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 mu m, and the continuous PSD was derived using a nonlinear least-squares method. Mean daily PM2.5 kitchen concentration and personal exposure was 1205 +/- 942 mu g/m(3) and 115 +/- 167 mu g/m(3), respectively, and the mean mass concentration consisted of a primary accumulation mode at 0.21 mu m and a secondary coarse mode at 3.17 mu m. Mean daily lung-deposited surface area (LDSA) and LDSA during cooking were 1009.6 +/- 1469.8 mu m(2)/cm(3) and 10,552.5 +/- 8261.6 mu m(2)/cm(3), 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.

Automated summary

This study characterized particle size distribution from biomass-related pollution and assessed lung-deposited doses using multiple-path deposition modeling. Results showed high PM2.5 concentrations in kitchen and personal exposures, with a primary accumulation mode at 0.21 µm and a secondary coarse mode at 3.17 µm. Additionally, the study provides unique data on lung deposition of biomass smoke.