Polycyclic aromatic hydrocarbons from environmental tobacco smoke and wood stoves dominate in settled house dust from Northwestern Ontario First Nations communities.

Rates of respiratory tract infections for children living in remote First Nations communities in the Sioux Lookout Zone in Northwestern Ontario are elevated and associated with poor indoor environmental quality including high exposures to endotoxin and serious dampness and mould damage. The studies also revealed a high prevalence of cigarette smoking and most houses have wood stoves, of variable quality. Depending on structure, polycyclic aromatic hydrocarbons (PAH) are carcinogens, immunotoxins and/or inflammatory mediators that are byproducts of the incomplete combustion of organic materials. Indoor sources of PAHs include tobacco smoke, cooking, and burning wood and/or fossil fuels for house heating. Twelve PAHs were measured in the <300 µm fraction of settled house dust by GC-MS in 59 houses. Nine PAHs were detected in all 59 houses, and median concentrations of individual PAHs measured ranged from 66 to 804 ng/g. PAHs associated with environmental tobacco smoke and with wood smoke dominated the PAH profile. Limiting tobacco smoking indoors and upgrading to low emission airtight wood stoves would improve indoor air quality and the respiratory health of children in this remote region of Ontario.