Abstract
Urban areas are undergoing a relative increase in non-point loads from road surfaces and rooftops. Manufacturing activities and motor vehicles produce exhaust gases containing micro-pollutants that are considered to adversely affect human beings and river ecosystems. These toxic substances accumulate on road surfaces on fair days and run off into river systems in the form of roadway drainage on rainy days. In this study, we measured the content of benzo(a)pyrene (B(a)P), which is a carcinogen in road-surface sediments, and experimentally quantified the rate of photolysis of B(a)P , in order to develop a prediction model to estimate B(a)P road-surface sediment and runoff loads. The characteristics (such as pollution load generation, distribution and attenuation) of B(a)P road-surface sediment loads were clarified, and a method was developed to identify parameters for a model to predict these loads. The findings of this study will enable more quantitative predictions to be made concerning B(a)P road-surface sediment and runoff loads, which will help provide greater accuracy when countermeasures and the control of non-point loads will be considered in the future.
