Environmental Health Criteria, No 197
World Health Organization
ISBN-13    9789241571975 ISBN-10    9241571977
Order Number    11600197 Format    E-book collection (PDF)
Price    CHF    26.00 / US$    31.20 Developing countries:    CHF    18.20
English     1997        101   pages
Table of contents
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Translation(s) available
Evaluates the risks to human health and the environment posed by exposure to demeton-S-methyl, a systemic and contact organophosphorus insecticide and acaricide having high acute toxicity. The compound has been used for over 30 years to protect cereals, fruits, vegetables, and ornamental plants.
Studies of the environmental behaviour of demeton-S-methyl indicate that the compound is rapidly metabolized in soil, plants, and mammals, does not persist, and is not accumulated by organisms. Workers may be exposed during manufacturing or application via the dermal or inhalation routes. Residues in food crops are identified as the principal source of exposure for the general population. Although data on dietary levels are limited, the report concludes that exposure of the general population to residues in food is unlikely to cause adverse effects on health.
Concerning effects on experimental animals and in vitro test systems, the report cites abundant evidence that demeton-S-methyl causes cholinergic toxicity. The report found no evidence of embryotoxic or teratogenic potential, adverse effects on reproduction or development, or carcinogenic action.
The evaluation of effects on human health draws on several reports of accidental and suicidal poisoning in the general population, and episodes of poisoning in inadequately protected workers. These findings confirm the high acute toxicity demonstrated in experimental studies. The report concludes that demeton-S-methyl should be handled and applied only by well-trained and closely-supervised operators. When good work practices, hygienic measures, and recommended safety precautions are followed, exposure to the compound during manufacturing or application was judged unlikely to cause adverse effects on health.