Aquatic Toxicology 79 (2006) 105–113 Coplanar and non-coplanar congener-specificity of PCB bioaccumulation and immunotoxicity in sea stars Bruno Danis a,∗ , Chantal Cattini b , Jean-Louis Teyssi´ e b , Jean-Pierre Villeneuve b , Scott W. Fowler b,1 , Michel Warnau b a Laboratoire de Biologie Marine CP160/15, Universit´ e Libre de Bruxelles, 50 Avenue FD Roosevelt, B-1050 Brussels, Belgium b International Atomic Energy Agency, Marine Environment Laboratory, 4 Quai Antoine 1er, MC 98000 Monaco, France Received 21 December 2005; received in revised form 16 May 2006; accepted 17 May 2006 Abstract The sea star Asterias rubens (L.), a representative species of the North Sea benthic environment, was exposed to a mixture of 10 selected PCB congeners (3 coplanar or c-PCBs, and 7 non-coplanar) via experimentally contaminated sediments. Both the degree of bioaccumulation and subsequent immunotoxic effects of these PCBs were determined. A strong congener-specificity for both bioaccumulation and immunotoxicity was found as well as a probable induction of a congener-specific detoxification mechanism resulting in the dramatic decrease in body levels of the three coplanar congeners tested (PCBs 77, 126 and 169). Moreover, a correlation was found between the bioaccumulation of c-PCBs and their immunotoxic effects. These findings suggest that coplanar congeners should be included in the list of congeners recommended to be analyzed for biological impact-oriented marine monitoring programmes. © 2006 Elsevier B.V. All rights reserved. Keywords: Polychlorinated biphenyls; Echinoderms; Bioaccumulation; Immunotoxicity; Detoxification 1. Introduction Polychlorinated biphenyls (PCBs) are among the persistent organic pollutants (POPs) of greatest concern in marine ecosys- tems owing to their persistence in the environment and the fact that they are readily bioaccumulated and highly toxic for aquatic organisms (Stebbing et al., 1992; OSPAR, 2000). Although in some cases PCB levels have been shown to decrease region- ally, a global decline in PCB concentrations is thought to be unlikely because of continual inputs into the environment mainly due to leakages from landfills and emissions from incinerators (Tanabe, 1988). PCBs have become truly ubiquitous, and have been detected even in the most remote locations, such as the polar regions or the deep sea (Ballschmiter et al., 1997; Stegeman et al., 2001). Another worrisome fact is that the quantities of PCBs still in use in the late 1980s exceeded the amount that had been released into the environment until that time (Ballschmiter et al., ∗ Corresponding author at: Royal Institute of Natural Sciences, 29, rue Vautier, B-1000 Brussels, Belgium. Tel.: +32 2 6274272; fax: +32 2 6274277. E-mail address: bruno.danis@naturalsciences.be (B. Danis). 1 Retired from the IAEA since May 2003. Present address: 8 All´ ee des Orangers, F-06320 Cap d’Ail, France. 1997; Stegeman et al., 2001). In the marine environment, these contaminants mainly become associated with bottom sediments thereby posing a chronic threat to benthic ecosystems (Fowler et al., 1978; Boese et al., 1996). The PCB family is composed of 209 different congeners and about half of them have been detected in significant concen- trations in environmental samples (Metcalfe, 1994). Until the late 1970s PCBs were mainly analyzed as commercial mix- ture equivalents (e.g. Aroclor, Kaneclor; Duinker et al., 1991); however, by the late 1980s the need to adopt congener-specific approaches became widely accepted, since it was found that pro- cesses such as bioaccumulation, metabolism and toxicity could differ considerably from one congener to another (Duinker et al., 1989). The International Council for the Exploration of the Sea (ICES) has recommended the systematic consideration of six PCB congeners for monitoring purposes, viz. IUPAC#28, 52, 101, 138, 153 and 180. This selection (with congener #118 added) was subsequently adopted and recommended by the World Health Organization (WHO, 1999). However, it is now widely accepted that the toxicity of such mixtures is mainly due to only a few congeners, viz. the non-ortho-substituted and mono-ortho-substituted coplanar congeners (Duinker et al., 0166-445X/$ – see front matter © 2006 Elsevier B.V. All rights reserved. doi:10.1016/j.aquatox.2006.05.004