A revised risk assessment for
toxaphene was developed, based on the assumption that fish consumers are only exposed to
toxaphene residues that differ substantially from technical
toxaphene due to environmental degradation and metabolism. In vitro studies confirmed that both technical
toxaphene and degraded
toxaphene inhibit gap junctional intercellular communication that correlates with the mechanistic potential to cause
tumor promotion. In vivo rat studies established the NOAEL for degraded and technical
toxaphene at the highest dose tested in the bioassay.
Toxaphene residue intakes from European fishery products were estimated and compared to the provisional tolerable daily intakes (TDIs) from various regulatory agencies including Canada, the United States, and Germany. The estimated intake was also compared to a new calculated provisional MATT pTDI. The MATT pTDI is based on new toxicological information (in vivo rat studies) developed on a model for environmental
toxaphene residues rather than technical
toxaphene. A MATT pTDI (1.08 mg total
toxaphene for a person of 60 kg) for
tumor promotion potency was adopted for use in Europe and is referred to here as the MATT pTDI. These new data result in a better estimate of safety and a higher TDI than previously used. Based on realistic fish consumption data and recent baseline concentration data of
toxaphene in European fishery products, the
toxaphene intake for the consumers of Germany, Ireland, Norway, and the Netherlands was estimated. For an average adult fish consumer, the average daily intake of
toxaphene was estimated to be 1.2, 0.4, 0.5, and 0.2 µg for the consumers of Norway, Germany, Ireland, and the Netherlands, respectively. The
toxaphene intake of these average fish consumers was far below the MATT pTDI of 1.08 mg/60 kg bw. In conclusion, based on the most relevant toxicological studies and the most realistic estimates of fish consumption and recent concentrations of
toxaphene in European fishery products, adverse health effects are unlikely for the average European consumer of fishery products. In no case is the MATT pTDI exceeded.