Comparative assessment of ecotoxicity of urban aerosol
In addition to its mass concentration, the health effects of urban particulate matter may depend on its particle size distribution and chemical composition. Yet air pollution regulations rely on exclusively bulk PM 10 concentration measurements, without regard to their potentially different health effects under different conditions. Aerosols from various sources are well known to contain a plethora of toxic, carcinogenic, mutagenic or teratogenic constituents such as heavy metals and polycyclic aromatic hydrocarbons. Extensive public health studies established the link between mass concentrations of PM 2.5 / PM 10 and health problems within the population. However, little is known about the relative importance of PM from different sources and the effect of seasonality on the toxicity. Here we present the application of a simple and sensitive method for the direct assessment of the overall ecotoxicity of various PM 2.5 / PM 10 samples collected on filters. The method is based on the Vibrio fischeri bioluminescence inhibition bioassay that has been standardized for solid samples, representing a relevant biological exposure route. Direct emission samples proved to be significantly more ecotoxic than photochemically processed aerosol, thus marked differences were observed between the ecotoxicities of urban PM 10 in summer and winter. These effects of urban PM 10 may be useful supplementary indicators besides the mass concentrations of PM 2.5 / PM 10 in cities.