TEMPORAL VARIATIONS OF PARTICULATE AIR-POLLUTION - A MARKER FOR FREE-RADICAL DOSAGE AND ADVERSE HEALTH-EFFECTS

Statistical associations have been observed between human mortality an d fine and sulfate particles. However, significant gaps in our knowled ge exist in explaining the observed health effects based on results fr om controlled exposure studies. It is possible that the causative agen t is a species that is correlated with particulate matter, but not mea sured by routine sampling of atmospheric aerosols. Free radicals, such as hydroxyl radicals, are responsible for the formation of fine and s ulfate particles. They are also known to be damaging to lung tissue, a s well as playing a role in the pathogenesis of a wide variety of dise ase states, including inflammation and cancer. These observations sugg est that radicals may be at least partly responsible for adverse healt h effects, and that fine particle mass could serve as a marker for fre e radical dosage. Applying receptor models to time-series aerosol data to determine the temporal variations oi source contributions may prov ide additional insight regarding mixtures of species that cause a disp roportionate fraction oi the health effects.