Abstract

Environmental pollutants frequently exist as complex mixtures of chemical and non-chemical constituents. For example, particulate matter (PM) air pollution is a mixture of solid and liquid particles with diverse physical and chemical properties. Complex pollutant mixtures like PM are often formed when multiple sources (e.g. biomass burning or traffic) contribute pollutants to the mixture. Information about which sources contribute to a pollution mixture is important to identifying major polluters and to developing strategies to reduce pollution.