EVALUATION OF TOXICITY AND SEX-RELATED VARIATION OF PCB LEVELS IN MEDITERRANEAN STRIPED DOLPHINS AFFECTED BY AN EPIZOOTIC

Individual PCB congener concentrations, including non-ortho chloro sub stituted, were determined in 30 striped dolphins (Stenella coeruleoalb a) affected by the 1990-92 Mediterranean epizootic to investigate thei r toxic potential. PCB congener concentrations in these dolphins were among the highest ever found in comparable studies on marine mammals. Concentrations in males and females were significantly different becau se of pollutant transfer to offspring by females. Thus, PCB concentrat ions and 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) toxic equivalents (TEQ) in males were approximately double those in females. Non-ortho, mono-ortho and di-ortho coplanar congeners accounted for approximately one third of the overall toxicity assessed through toxic equivalent f actors (TEFs), as defined by Ahlborg et al. (1994). Di-ortho congener 170 and non- ortho congener 126 were the major contributors to TEQ (33 % and 30% respectively). Copyright (C) 1996 Elsevier Science Ltd