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(47-07) Risk Assessment of Hexachlorobenzene for the Marine Environment-Osparcoma Region North Sea. Poole, Alan1, De Rooij, Christ2, Gard, Arielle3, Garny, Veronique4, Lecloux, Andre4, Papp, Roger5, Thomas, Paul6, Thompson, Roy7, Van Wijk, Dolf*,4, 1 Dow Chemicals Europe, Horgen, Switzerland2 Solvay SA, Brussels, Belgium3 Rhodia, Lyon, France4 Euro Chlor, Brussels, Belgium5 CNEEIC, Paris, France6 Atofina SA, Paris, France7 Astra-Zeneca, Brixham, UK ABSTRACT- The chlorine producers in Europe (Euro Chlor) have carried out marine risk assessments (North Sea environment) for some 25 key chemicals related to the chlorine industry, using methodology based on the European Union Technical Guidance Document for chemical risk assessment. The assessments consisted of the collection and evaluation of data on adverse effects and on environmental concentrations. The effect data were derived from laboratory toxicity tests and the exposure data were obtained from monitoring programs. Based on the effects (expressed as PNEC) and the exposure (expressed as PEC) the risks were characterized by PEC/PNEC ratios. This study deals with the assessment of the environmental risks of hexachlorobenzene (HCB) considering four scenarios. The risk to aquatic organisms was assessed based on aquatic exposure, the risk to fish through bioconcentration, the risk to sediment organisms and the risk to fish-eating predators via biomagnification. Based on the calculated PEC/PNEC ratios for the various scenarios it can be concluded that the present levels of HCB in surface water are unlikely to represent a risk to aquatic organisms in the North Sea region. This conclusion is supported by considering the bioconcentration in fish, which demonstrates that the exposures as determined by monitoring data are far below the critical body burden. Furthermore, the current levels of HCB in sediment are unlikely to be of risk to organisms living in sediments. The data also indicate little risk of general toxicity occurring in fish eating mammals or birds. It cannot be excluded however, that adverse reproductive effects may occur in highly sensitive species such as mink, ferret, or other fish-eating mammals, since their dietary effect levels are only a few times higher than concentrations of HCB measured in various species of fish. Nonetheless environmental HCB concentrations continue to show a decreasing trend with time. This study also illustrates that if sufficient information is available, also for PTB (persistent, bioaccumulative and toxic) substances safe environmental levels can be determined using risk assessment methodology. Key words: hexachlorobenzene, marine risk assessment, PTB, Monitoring |
