Composition and oxidative potential of PM2.5 pollution and health

There is evidence that the health damage from PM2.5 pollution varies with particle composition and that particles with high proportions of elemental or organic carbon, or high oxidative potential (OP) might be more detrimental to pulmonary health. A study in Ontario, Canada with relatively low average PM2.5 (7.1 μg/m3 ) measured the depletion of anti-oxidants glutathione (GSH) and ascorbate (AA) in PM2.5 sampled from 19 locations. At low PM2.5 pollution (3-day mean <10 μg/m3 ), the effect of increasing PM2.5 exposure on respiratory diseases was worse in locations with high GSH depletion. As well as indicating a possible mechanism for the health damage from PM2.5 exposure, this research confirms that PM2.5 pollution is detrimental to health at levels well below current guidelines. In Canada, 55% of PM2.5 emissions (excluding open and natural sources) originate from home firewood burning, despite only 6% of Canadian households using wood as the main form of heating. A good strategy would be to use all cost-effective means to reduce PM2.5 exposure, including effective education programs on the sources and health hazards of PM2.5 pollution and heeding the UN Environment Program recommendation to phase out logburning stoves in developed countries.