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I C Munro

Publications and source records attributed to I C Munro.

At least 55 records · Page 3Linked to original sources

Toxicological procedures for assessing the carcinogenic potential of agricultural chemicals.

Pesticides and other agricultural chemicals are now widely used throughout the world as a means of improving crop yields in order to meet the increasing demands being placed upon the global food supply. In Canada, the use of such chemicals is controlled through government regulations established jointly by the Department of Agriculture and the Department of National Health & Welfare. Such regulations require a detailed evaluation of the toxicological characteristics of the chemical prior to its being cleared for use. In this paper, procedures for assessing the carcinogenic potential of agricultural and other chemicals are discussed. Consideration is given to both the classical long-term in vivo carcinogen bioassay in rodent or other species and the more recently developed short-term in vitro tests based on genetic alterations in bacterial and other test systems.

Animals↗

Chronic toxicity of methylmercury in the adult cat. Interim report.

Doses of 3, 8.4, 20, 46, 74 or 176 mug Hg/kg/day were fed to groups of 8--10 adult cats, either as methylmercuric chloride or as methylmercury-contaminated fish, 7 days/week for up to 2 years. Food consumption, body weight change, blood mercury levels, haematology, urine analysis, serum blood urea nitrogen (BUN) levels and neurological status were assessed regularly in all animals. Clinical signs of methylmercury toxicity -- consisting of ataxia, loss of balance and motor incorrdination -- occured in groups receiving 176 mug Hg/kg/day after 14 weeks of treatment. Pathological findings were confined to the nervous system and consisted of loss of nerve cells with replacement by reactive and fibrillary gloisis. Terminal blood and brain mercury levels were approx. 10 ppm. There were no differences in the time required to develop clinical signs of methylmercury toxicity, tissue mercury levels or pathology between the groups of cats receiving methylmercury as methylmercuric chloride or as methylmercury-contaminated fish, at either dose level. Blood mercury levels in the remaining doses groups appeared to plateau after 40 weeks of treatment. Groups receiving 46 mug Hg/kg/day began to show some neurological impairment after 60 weeks of treatment which did not progress in subsequent weeks. No treatment-related effects were present in groups receiving 20, 8.4 or 3 mug Hg/kg/day after 2 years.

Animals↗