Assessment of toxicity of polycyclic aromatic hydrocarbons in sediments of Kaohsiung Harbor, Taiwan.

Polycyclic aromatic hydrocarbon (PAH) contamination and toxicity levels in the surface sediments of Kaohsiung Harbor, Taiwan were evaluated using sediment quality guidelines (SQGs) and toxic equivalent factors. Eighty surface sediment samples were collected from twenty locations in Kaohsiung Harbor for PAH analysis using gas chromatography/mass spectrometry (GC/MS). Concentrations of total PAHs varies from 34.0 to 16,700 ng/g with a mean concentration of 1490±2689 ng/g. The spatial distribution of PAHs reveals that PAH concentration is relatively higher in the river mouth regions, especially in the Salt River mouth where it gradually diminishes toward the harbor region. Distributions of PAHs, during both the wet and dry seasons, show that PAHs are more easily disbursed in the receiving sea water thereby leading to a wider range of chemical distribution. Hence, most of the chemicals accumulate in the harbor water channel. Diagnostic ratios show that the possible source of PAHs in the southern industrial area of the harbor could be coal combustion while in the other zones it could be petroleum combustion and/or a mixed sources. The toxic equivalent concentrations (TEQ(carc)) of PAHs varied from 3.9 to 1970 ng TEQ/g. The higher total TEQ(carc) values were found in the southern industrial area of the harbor. As compared with US sediment quality guidelines, the observed levels of PAHs in the industrial zone exceeded the effects range low (ERL), which will eventually cause acute biological damage. Based on the analyses using the SQGs, surface sediments from Kaohsiung Harbor were moderately contaminated and most samples have a low probability of toxicity pollution, except for the Salt River mouth situated in the south Kaohsiung Harbor area. This area has a medium to high probability of toxicity pollution.