Toxicity of artificial runoff fostered with dry deposition particulates from industrial, commercial, and highway area in Gwangju, Korea

摘要

The adverse effects of rainwater and artificial urban runoff (an imitation of urban runoff during rainfallnevent) were investigated using a battery of bioassays employing three test species. Urban dusts werencollected at three representative sites; commercial, industrial and highway areas. The water qualitynparameters of rainwater and artificial runoff revealed low hardness (23.4 , 34.2mg·L21 as CaCO3)nand alkalinity (7.0 , 34.2mg·L21 as CaCO3). High toxicities were observed in the bioassays for thenartificial runoffs. The average toxic units for D. magna, S. capricornutum, and O. latipes weren1.26(^0.84), 1.34(^1.10) and 2.05(^1.08), respectively. Of these species, O. latipes revealednsignificantly higher toxicity compared to D. magna and S. capricornutum (p , 0.05). Embryo lesionsnwere observed with 6.25% treatments, and these significantly increased at 12.5% treatmentsn(p , 0.05). The EC50 values for each artificial runoff were 22.5, 22.6 and 25.4% for commercial,nindustrial and highway areas, respectively. With 12.5% treatment, significant delays in hatching timesnwere observed (p , 0.05); all embryos tested did not hatched at 100% treatment. Similarly, ansignificant decrease in hatching success was observed at every sampling point from 25% treatmentn(p , 0.05). The adverse effects of artificial runoff on the three test species suggests that urbannsurface runoff can cause significant impairment in aquatic ecosystems.