title: Toxicity of hydroxylated polychlorinated biphenyls (HO-PCBs) using the bioluminescent assay Microtox(®).
abstract: Hydroxylated polychlorinated biphenyls (HO-PCBs) are toxic contaminants which are produced in the environment by biological or abiotic oxidation of PCBs. The toxicity of a suite of 23 mono-hydroxylated derivatives of PCBs and 12 parent PCBs was determined using the bacterial bioluminescent assay Microtox(®). All HO-PCBs tested exhibited higher toxicity than the corresponding parent PCB, with effect concentration 50 % (EC50) ranging from 0.07 to 133 mg L(-1). The highest toxicities were recorded with 4-hydroxylated derivatives of di-chlorinated biphenyls (EC50 = 0.07-0.36 mg L(-1)) and 2-hydroxylated derivatives of tri-chlorinated biphenyls carrying a chlorine substituent on the phenolic ring (EC50 = 0.34-0.48 mg L(-1)). The toxicity of HO-PCBs generally decreased when the degree of chlorination increased. Consistently with this observation, a significant positive correlation was measured between toxicity (measured by EC50) and octanol-water partition coefficient (pK ow) for the HO-PCBs under study (Pearson's correlation coefficient, r = 0.74), which may be explained by the lower solubility and bioavailability generally associated with higher hydrophobicity. This study is the first one which assessed the toxicity of a suite of PCBs and HO-PCBs using the bioluminescent assay Microtox(®), showing an inverse correlation between toxicity and hydrophobicity.
authors.affiliation: Department of Civil and Environmental Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA, 19122, USA.
authors.forename: Renu
authors.initials: R
authors.lastname: Bhalla
authors.affiliation: Department of Civil and Environmental Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA, 19122, USA.
authors.forename: Rouzbeh
authors.initials: R
authors.lastname: Tehrani
authors.affiliation: Department of Civil and Environmental Engineering, Temple University, 1947 N. 12th Street, Philadelphia, PA, 19122, USA. bvanaken@temple.edu.
authors.forename: Benoit
authors.initials: B
authors.lastname: Van Aken
mesh_terms: D004785:Environmental Pollutants / Q000633:toxicity*; D008163:Luminescent Measurements; D011078:Polychlorinated Biphenyls / Q000633:toxicity*; D018675:Toxicity Tests / Q000379:methods*
chemical_list: D004785:Environmental Pollutants; D011078:Polychlorinated Biphenyls
keywords: Bioluminescent assay; Hydroxylated polychlorinated biphenyl–HO-PCB; Microtox®; Structure–activity relationship–SAR; Toxicity