Abstract
Pollution potential of road dusts which run off from road surfaces into receiving water during rain events are considered to be high. Road dusts contain micro toxic pollutants such as polycyclic aromatic hydrocarbons (PAHs) and heavy metals, which flow into the receiving water through no treatment facilities. So it is important to obtain knowledge on characteristics of such pollutants contained in the highway dusts. The authors have focused on pollutants originated from car traffics and collected highway dusts to measure content ratios of such pollutants in the dusts. As a result of examinations on the measured data, some significant findings were obtained. The data showed that road dusts in a winter season contained a lot of Na due to inclusion of snow melting agents. They also showed high content ratios of Zn and Cu of heavy metals in the road dusts. The examination showed a positive correlation between ClPAHs and its parent PAHs in small particle size, which implied that PAHs and ClPAHs were generated at the same time. On the other hand, PAHs and Cu were negatively correlated, which meant that Cu might be catalytic during photo decomposition of PAHs.
