Environmental mercury and man : a report of an Inter-departmental Working Group on Heavy Metals.

  • Great Britain. Inter-departmental Working Group on Heavy Metals
Date:
1976
Catalogue details

Licence: Open Government Licence

Credit: Environmental mercury and man : a report of an Inter-departmental Working Group on Heavy Metals. Source: Wellcome Collection.

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    ingestion of treated seeds, have generally been attributed in the UK to organo- chlorine pesticides that were used in association with the mercury compounds, rather than to the mercury compounds themselves. High levels of mercury in fish in Sweden (and in birds feeding on them) were also attributed to the widespread use of mercury compounds as slimicides in pulp and paper mills. 4. Another hazard, of great immediate consequence to man, came to light in Japan and ultimately gave rise to the term ‘Minamata Disease’. It arose from the massive and prolonged discharge of mercury compounds formed from catalysts used in acetaldehyde and vinyl chloride production to the waters of Minamata Bay. Here, natural processes probably converted some of the mercury content of effluents into methylmercury compounds, which are a particular hazard to health, although this form of mercury was also present in the discharge itself. The methylmercury compounds were then accumulated in the tissues of fish living and feeding in the bay. Since the diets of local fishermen and their families largely consisted of fish, many of these people had an excessively high intake of mercury, and in particular of methylmercury com- pounds. This incident resulted in the poisoning of 121 people, of whom 46 died, in the period 1953-1970 (Takeuchi, 1972a). Twenty-two infants with brain damage (palsy and retardation) were born to mothers who were mainly symptom-free and this indicates transplacental foetal damage and the possible concentration of methylmercury in the foetus (WHO, 1972). These unfortunate people, or their heirs, have recently been awarded financial compensation in the Japanese courts for injuries and disabilities resulting from exposure to mercury (Anon, 1973). By March 1975 there were 684 officially verified patients and 115 had died (Environment Agency, 1975). A similar incident occurred around the Agano River, Niigata, Japan, from 1965 onwards; in this case by March 1975 there were 516 certified victims of poisoning and 23 deaths (Environment Agency, 1975). A third outbreak of the disease has recently been reported (Japan Times, 1973) but this has not been confirmed (Environment Agency, 1975). In these incidents many domestic animals, particularly cats, were also affected as were fish, shellfish and seabirds. Disasters of this type or magnitude have not occurred in any other country, although recent reports (e.g. Smith and Smith, 1975) indicate the possible existence of a problem in Canada; having set a maximum limit on the concentration of mercury in fish, Sweden, Canada and the USA have thought it necessary to prohibit removal and sale of fish from certain of their waters on occasion. 5. Another source of severe damage to human health which occurred in Iraq, Pakistan, Guatemala and the USA arose from incidents involving the con- | sumption of food containing high concentrations of mercury derived from alkylmercury agricultural seed-treatments. These treatments use organic com- pounds of mercury which are applied to seeds (e.g. grain etc.) to prevent seed- borne disease. In Iraq, treated seeds, intended for planting, had inadvertently been used to make bread (Bakir et al, 1973): in the USA, livestock was fed on treated grain, and then slaughtered for human consumption (Curley et al, 1971). In both instances, severe poisoning or death has occurred, particularly in Iraq, z
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