Polycyclic aromatic hydrocarbons (PAHs) and dioxins have several toxic properties, including mutagenicity, carcinogenicity and reproductive toxicity. PAHs mainly originate from the burning of petroleum and coal, while dioxins originate mainly from waste incineration and agrochemicals. Both PAHs and dioxins have aryl hydrocarbon receptor (AhR) binding activity which is related to toxicity of PAHs and dioxins.
In this study, we evaluated AhR binding activity of airborne particles collected in Beijing, China and Kanazawa, Japan by DR-CALUX and the contribution of PAHs and dioxins to this activity. AhR binding activity of airborne particles in Beijing (1,200 ng • m^-3) was four hundred times higher than in Kanazawa (2.7 ng • m^-3). The composition of PAHs didn′t show large difference in Beijing and Kanazawa. The contribution of the PAHs to CALUX-TEQ was higher than dioxins and especially high in Kanazawa (10.4 %). These results suggest that PAHs show large contribution to the toxicity of airborne particles, and other kinds of PAH and PAH related compounds will also contribute to that toxicity. The difference of concentration and composition of these compounds result in the different level of toxicity of airborne particles in each city.