Seasonal Differences in Rural Particulate Matter Ecotoxicity

The composition of atmospheric particulate matter, including particle-bound polyaromatic hydrocarbons, generally shows a clear seasonal pattern which is reflected in its ecotoxicity as well. This study aimed at characterising seasonal differences in the ecotoxicity of rural aerosol samples applying both luminescent bacteria and higher plants as test organisms. Higher plant phytotoxicity was assessed by the Sinapis alba root growth inhibition test and the Vegetative Vigour Test. Different bioassays and end-points showed different sensitivity: while the Sinapis alba assay showed no toxic effect, luminescent bacteria proved an excellent screening tool, detecting no toxicity in the summer sample and the highest inhibition in the winter sample, with EC20 = 9.87%. In the case of Vegetative Vigour Test, parallel application of different end-points revealed that atmospheric particulate matter might have a Janus-faced effect: stimulation of photosynthetic pigments due to nutrient content and growth impairment due to toxic components.