Contamination by mercury and cadmium in the cetacean products from Japanese market.

Cetaceans hunted coastally in Japan include several species of odontocete (dolphins, porpoises and beaked whales), and fresh and frozen red meat and blubber, as well as boiled internal organs, such as liver, lung, kidney and small intestine, are still sold for human consumption. Furthermore, red meat and blubber products originating from mysticete minke whales caught in the Antarctic and Northern Pacific are also sold for human consumption. We surveyed mercury and cadmium contamination levels in boiled liver, lung, kidney and red meat products being marketed in Japanese retail outlets. We also analyzed the DNA of these products to obtain information concerning gender and species. Total mercury (T-Hg) and methyl mercury (M-Hg) contamination levels in all the cetacean products were markedly higher in odontocete species than in mysticete species, and slightly higher in females than in males. T-Hg contamination in the organs was seen in the following order: boiled liver>boiled kidney=boiled lung>red meat. In particular, T-Hg concentrations in the boiled liver were high enough to cause acute intoxication even from a single ingestion: the mean +/-SD (range) of T-Hg was 388+/-543 (0.12-1980) microg/wetg. In contrast, although M-Hg contamination in the liver was not markedly higher than that in other organs, M-Hg contamination was in the following order: boiled liver>odontocete red meat>boiled kidney>boiled lung. The contamination levels of T-Hg and M-Hg in odontocete red meat, the most popular whale product, were 8.94+/-13.3 and 5.44+/-5.72 microg/wetg, respectively. These averages exceeded the provisional permitted levels of T-Hg (0.4 microg/wetg) and M-Hg (0.3 microg/wetg) in marine foods set by the Japanese Ministry of Health, Labor and Welfare by 22 and 18 times, respectively, suggesting the possibility of chronic intoxication by T-Hg and M-Hg with frequent consumption of odontocete red meat. Cadmium contamination levels in boiled liver, kidney and lung were 8.59+/-12.0, 10.4+/-8.6 and 1.66+/-1.27 (microg/wetg), respectively.

Human health significance of organochlorine and mercury contaminants in Japanese whale meat.

The concentrations of total mercury, polychlorinated biphenyls (PCBs), and organochlorine pesticides (SigmaDDT, dieldrin, hexachlorobenzene [HCB], and SigmaHCH) were determined in 61 whale meat products (bacon, blubber, red meat, liver, intestine, and tongue) purchased from retail outlets across Japan. Mean (range) concentrations of contaminants in all samples were: total mercury 4.17 (0.01-204); SigmaPCB 1.14 (0-8.94); SigmaDDT 0.98 (0-7.46); dieldrin 0.07 (0-0.35); HCB 0.06 (0-0.22); and SigmaHCH 0.07 (0-0.19) micro g/g (wet weight). The data were used to calculate estimated daily intakes (EDIs) of contaminants at two hypothetical levels of whale meat consumption. These EDIs were compared with FAO/WHO "tolerable daily intake" (TDI) values for each chemical. EDIs calculated for higher levels of whale meat consumption were in some cases exceptionally high and for many products exceeded FAO/ WHO-TDIs for total mercury, PCBs, and dieldrin, with exceedance factor values (EDI/TDI) for total mercury, PCBs, and dieldrin reaching maxima of 175, 5.36, and 2.1, respectively. For sensitive consumers and those with high-level consumption (e.g., whaling communities), exposure to mercury and to a lesser extent PCBs from certain whale blubber and bacon and striped dolphin liver products could lead to chronic health effects. The Japanese community should therefore exercise a precautionary approach to the consumption of such foods in excess, particularly by high-risk members of the population.

Methyl sulphone metabolites of polychlorinated biphenyls (PCBs) in cetaceans from the Irish and the Aegean Seas.

The levels of PCBs and PCB methyl sulphone metabolites were determined in the blubber of six species of cetaceans that originated from the Irish Sea and the Aegean Sea (Mediterranean). Burdens ranging from 2.80 to 27.80 microg g-1 (lipid weight) total PCBs and 0.03 to 0.58 microg g-1 (lipid weight) total methyl sulphones were recorded. The highest cetacean methyl sulphone burden (0.58 microg g-1) was in an Irish Sea harbor porpoise (Phocoena phocoena). Methyl sulphone isomer formation capacity, as determined by PCB:MSF ratios, varied considerably between species as follows: harbour porpoise (1:10) > pilot whale (Globicephalus melas), white-sided dolphin (Lagenorhyncus acutus) (1:50) > common dolphin (Delphinus delphis), Risso's dolphin (Grampus griseus), and striped dolphin (Stenella coerueoalba), (1:100), and was related to interspecific variation in PCB methyl sulphone formation capacity.

Organochlorines and mercury in pilot whale blubber consumed by Faroe islanders.

Some 22,000 pilot whales (Globicephala melaena) were taken in the Faroe Islands between 1970 and 1992. It is known that tissues from these animals are widely consumed by the islanders. The position of these animals at the apex of a direct marine food chain renders them liable to accumulate toxic chemicals, such as metals and organochlorines. Although the consumption of contaminating metals in pilot whale tissues has been studied, the significance of blubber as a dietary source of organochlorine compounds has not been fully considered. This study reports levels of organochlorine and mercury contamination in the blubber of pilot whales taken in two Faroese kills. Published estimates of pilot whale tissue consumption are used to evaluate dietary organochlorine intake in relation to established national and international guidelines and clinical studies conducted in the North American Great Lakes.

Organochlorine contamination in pinnipeds.

Organochlorines, such as PCBs and DDT, are ubiquitous contaminants. Most studies reporting concentrations of organochlorines in pinnipeds have investigated ringed, grey, and harbour seals. Very few studies have been carried out on pinnipeds from the southern hemisphere. Pre-1980, the highest mean wet-weight blubber concentrations of DDT and related metabolites (911 +/- 582 micrograms g-1) were recorded in sea lions from California. The highest pre-1980 blubber concentrations of PCBs (1470 +/- 922 micrograms g-1) were recorded in harbour seals from the Netherlands. In later studies, the highest blubber concentrations of PCBs have been recorded from grey seals of the Dee estuary, UK [46.79 (10.17-116.68) micrograms g-1]. The highest DDT concentrations measured in individual pinnipeds appear to be in the 1-15 micrograms g-1 range, and such levels have been recorded from ringed, grey, and harbour seals and Australian fur seals. There are problems in identifying trends based on different studies. These include the improvement in analytical methods with time and the lack of uniformity in analytical methodology between laboratories as well as in the biological material analyzed. Insufficient standardized studies have been undertaken for a clear picture of temporal trends in DDT and PCB concentrations in pinniped tissues to be identified. Reported results show variations in contaminant concentrations between pinniped colonies from different sites, and special reference has been made to comparison of contaminant burdens between the UK colonies. Insufficient standardized information is currently available for patterns of contamination in pinnipeds to be assessed on a global scale. Many, although not all, studies have shown evidence for age and sex correlation for organochlorine concentrations in pinnipeds; male seals continuing to accumulate certain organochlorines throughout their lives; female seals accumulating these compounds until maturity when they lose part of their body burdens to their offspring via transplancental transfer and, more importantly, via lactation. The ability of pinnipeds to metabolize organochlorine compounds appears to be less well developed than in terrestrial mammals and seems to vary between seal species. Reported effects on pinnipeds, which have been suggested to result from organochlorine contamination, include skeletal deformities and impacts on reproduction, such as uterine blockages. The evidence of a relationship between recent epizootics in marine mammal populations and organochlorine pollution suggests that viruses and pollution are potential significant contributors to mortalities, but other factors, such as unseasonably warm temperatures and high seal densities, cannot be precluded.(ABSTRACT TRUNCATED AT 400 WORDS)

Organochlorine and mercury contamination in United Kingdom seals.

In 1988 and 1989 tissue samples were obtained from the grey seal (Halichoerus grypus) population found in the Dee estuary in the north west of England and from harbour seals (Phoca vitulina) from the populations in the Wash and north east Scotland and analysed for mercury and organochlorine compounds. Adult seals from the Dee estuary were highly contaminated with mercury and polychlorinated biphenyls (PCBs), and one animal from the Dee contained traces of dichlorodiphenyltrichloroethane (DDT), suggesting the recent use of this banned pesticide. The levels of hexachlorobenzene in the livers of two Dee seals exceeded those in the blubber, possibly indicating liver malfunction or recent exposure. The same relationship was found for hexachlorobenzene in three specimens from the Wash and, in one of these animals, the liver was also more highly contaminated than the blubber with dieldrin and PCBs. Levels of contamination were lower in seals from the Wash and even lower in animals sampled in Scotland, where only dichlorophenyldichloroethylene, the metabolite of DDT, was routinely detected. The toxicological significance of the results is discussed, particularly in relation to the mortality observed in the seal epizootic of 1988.