Correlation between response of human cell line and distribution of sediment polycyclic aromatic hydrocarbons and polychlorinated biphenyls on Palos Verdes Shelf California, USA

Sections of a sediment core collected from Station 7C near the County Sanit ation Districts of Los Angeles County, California, USA, outfall were analyz ed for total organic carbon (TOC), polycyclic aromatic hydrocarbons (PAHs), and polychlorinated biphenyls (PCBs). In addition, the biological response s to extracts from the same samples were determined using the P450 reporter gene system (RGS) assay. The profiles of TOC, PAHs, and PCBs were consiste nt in illustrating the predischarge baseline and the effects of improving w astewater treatment. Induction of the CYP1A1 gene using P450 RGS was correl ated with total PAHs (r(2) = 0.47) and better correlated with the B[a]P tox ic equivalency quotients (r(2) = 0.63) calculated using toxic equivalency f actors (TEFs) derived from P450 RGS analyses of individual high molecular w eight (4 to 6 rings) PAHs. Results from short (6 h) and long (16 h) exposur es using the RGS assay suggested that a portion of the induction was from t he slower acting chlorinated hydrocarbons (coplanar PCBs, dioxins, furans, etc.). Coplanar PCBs in the amounts of 0.9 to 3.1 mu g/g were found in thre e core sections analyzed; hence, the induction of RGS was likely produced b y both PAHs and coplanar PCBs. Since dioxins and furans were not analyzed, their contributions to the RGS responses are unknown. The RGS assay may be used to screen samples for potential toxicological importance before conduc ting costly chemical analyses.