Abstract
Highway pollutants which contain micro toxic substances with carcinogenic and/or estrogenic nature such as polycyclic aromatic hydrocarbons (PAHs) have an influence on receiving water. Authors have examined an ecological impact of such highway pollutants on aquatic life using a methodology of Whole Effluent Toxicity (WET) which is usually applied for an effluent management from point sources. From their examinations, one of the findings was that highway dusts which accumulated during a winter season were remarkably toxic in the ecological environment. This study is aimed at investigating characteristics of micro toxic pollutants such as PAHs in highway dusts, and examining their ecological toxicity in terms of PAHs and their transformation products. It is also aimed at showing a mechanism of the remarkable toxicity of the road dust in winter season. Investigations of highway dusts and two types of ecological toxicity tests were carried out. They showed remarkable toxicity of some road dusts both in the field investigations and the laboratory tests. And they also showed that the toxicity could be due to PAHs and their transformation products such as ClPAHs. Some more examinations could clarify a mechanism of ecotoxicity of highway pollution.
