Air-Quality Assessment of On-Site Brick-Kiln Worker Housing in Bhaktapur, Nepal: Chemical Speciation of Indoor and Outdoor PM(2.5) Pollution

Brick workers and their families in Nepal generally live in poorly ventilated on-site housing at the brick kiln, and may be at higher risk for non-occupational exposure to fine particulate matter air pollution and subsequent respiratory diseases due to indoor and outdoor sources. This study characterized non-occupational exposure to PM(2.5) by comparing overall concentrations and specific chemical components of PM(2.5) inside and outside of brick workers’ on-site housing. For all samples, the geometric mean PM(2.5) concentration was 184.65 μg/m(3) (95% confidence interval: 134.70, 253.12 μg/m(3)). PM(2.5) concentrations differed by kiln number (p = 0.009). Kiln number was significantly associated with 16 of 29 (55%) air pollutant, temperature, or relative humidity variables. There was not a significant interaction between kiln number and location of sample for PM(2.5) (p = 0.16), but there was for relative humidity (p = 0.02) and temperature (p = 0.01). Results were qualitatively similar when we repeated analyses using indoor samples only. There was no difference in the chemical makeup of indoor and outdoor PM(2.5) in this study, suggesting that outdoor PM(2.5) air pollution easily infiltrates into on-site brick worker housing. Outdoor and indoor PM(2.5) concentrations found in this study far exceed recommended levels. These findings warrant future interventions targeted to this vulnerable population.