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1949. Chloroneb and the cow: An unfinished story
AGRICULTURAL CHEMICALS
327
from 2 months to 33 yr has been assessed in comparison with 33 age-matched control subjects with no known history of exposure to mercury. Urinary excretion of Hg by the seed dressers ranged from 4 to 91 /~g/24 hr and by the controls from 0 to 28.3/~g/24 hr. Urinary protein excretion ranged from 36 to 7400 and from 16 to 162 mg/24 hr respectively in the two groups. Blood concentrations of Hg in the seed dressers ranged from 0 to 20-8/~g/100 ml in contrast to the normal maximum of 6 ~g/100 ml. No significant difference in serum glutathione-reductase activity was apparent between the two groups, but there was evidence of inhibition of serum phosphoglucose-isomerase activity in the exposed persons. The significance of such findings for the future health of the seed dressers is considered to be uncertain. Nevertheless, the figures indicate that stricter protective measures are needed to reduce the occupational absorption of Hg from seed dressings. [From time to time the Ministry of Agriculture, Fisheries and Food issues warnings to users of organomercurial compounds, such as those used for the treatment of bulbs, stressing the importance of adequate supervision and adherence to recommended protective measures.] 1949. Chloroneb and the cow: An unfinished story Gutenmann, W. H. & Lisk, D. J. (1969). Metabolic studies with chloroneb fungicide in a lactating cow. J. agric. Fd Chem. 17, 1008. The possibility that residues of chloroneb (1,4-dichloro-2,5-dimethoxybenzene; I), a fungicide used on cotton seedlings, may reach milk as a result of the feeding of cottonseed meal to cows has prompted a study of the metabolism of I in that species. No residues of I were detected in the milk or faeces of a cow fed 5 ppm I for 4 days. When I was incubated with the 10,000 g supernatant fraction of fresh beef liver, a product with the characteristics of 2,5-dichloro-4-methoxyphenol (II), a known metabolite of I in animals, was detected by gas chromatography. A metabolite with corresponding characteristics was found in hydrolysed urine from the cow fed I. Assuming this compound to be II, the urinary excretion of 44-3 ~ of the estimated dose of I was thus accounted for. The fate of the remaining 55.7 % remains unknown, but it is pointed out that a metabolite derived from I by hydroxylation or reduction, with elimination of one or both chlorine atoms, would not have been detected by the technique used. A further experiment established that I was stable when incubated for up to 6 hr with rumen fluid. [The main fact established, that chloroneb does not appear in milk from cows consuming it, is reassuring; but it is tempting to speculate on the fate of the greater part of the dose.] 1950. Diquat digested Oreopoulos, D. G. & McEvoy, J. (1969). Diquat poisoning. Post-grad. med. J. 45, 635. While a number of fatalities have followed ingestion of the dipyridilium weed-killer, paraquat, and mixtures of paraquat with the related compound, diquat, have caused damage to the eyes and nails (Cited in F.C.T. 1969, 7, 89 & 687), there has been little opportunity for any study of the effects of diquat ingestion by man. A case has now been reported, however, in which a young man swallowed a small part of a mouthful of diquat. Diarrhoea, difficulty in swallowing, two small ulcers on the tongue and pharynx and general malaise were the only immediate effects, but because of previous experience with paraquat poisoning, forced diuresis was started. This was continued for
327
from 2 months to 33 yr has been assessed in comparison with 33 age-matched control subjects with no known history of exposure to mercury. Urinary excretion of Hg by the seed dressers ranged from 4 to 91 /~g/24 hr and by the controls from 0 to 28.3/~g/24 hr. Urinary protein excretion ranged from 36 to 7400 and from 16 to 162 mg/24 hr respectively in the two groups. Blood concentrations of Hg in the seed dressers ranged from 0 to 20-8/~g/100 ml in contrast to the normal maximum of 6 ~g/100 ml. No significant difference in serum glutathione-reductase activity was apparent between the two groups, but there was evidence of inhibition of serum phosphoglucose-isomerase activity in the exposed persons. The significance of such findings for the future health of the seed dressers is considered to be uncertain. Nevertheless, the figures indicate that stricter protective measures are needed to reduce the occupational absorption of Hg from seed dressings. [From time to time the Ministry of Agriculture, Fisheries and Food issues warnings to users of organomercurial compounds, such as those used for the treatment of bulbs, stressing the importance of adequate supervision and adherence to recommended protective measures.] 1949. Chloroneb and the cow: An unfinished story Gutenmann, W. H. & Lisk, D. J. (1969). Metabolic studies with chloroneb fungicide in a lactating cow. J. agric. Fd Chem. 17, 1008. The possibility that residues of chloroneb (1,4-dichloro-2,5-dimethoxybenzene; I), a fungicide used on cotton seedlings, may reach milk as a result of the feeding of cottonseed meal to cows has prompted a study of the metabolism of I in that species. No residues of I were detected in the milk or faeces of a cow fed 5 ppm I for 4 days. When I was incubated with the 10,000 g supernatant fraction of fresh beef liver, a product with the characteristics of 2,5-dichloro-4-methoxyphenol (II), a known metabolite of I in animals, was detected by gas chromatography. A metabolite with corresponding characteristics was found in hydrolysed urine from the cow fed I. Assuming this compound to be II, the urinary excretion of 44-3 ~ of the estimated dose of I was thus accounted for. The fate of the remaining 55.7 % remains unknown, but it is pointed out that a metabolite derived from I by hydroxylation or reduction, with elimination of one or both chlorine atoms, would not have been detected by the technique used. A further experiment established that I was stable when incubated for up to 6 hr with rumen fluid. [The main fact established, that chloroneb does not appear in milk from cows consuming it, is reassuring; but it is tempting to speculate on the fate of the greater part of the dose.] 1950. Diquat digested Oreopoulos, D. G. & McEvoy, J. (1969). Diquat poisoning. Post-grad. med. J. 45, 635. While a number of fatalities have followed ingestion of the dipyridilium weed-killer, paraquat, and mixtures of paraquat with the related compound, diquat, have caused damage to the eyes and nails (Cited in F.C.T. 1969, 7, 89 & 687), there has been little opportunity for any study of the effects of diquat ingestion by man. A case has now been reported, however, in which a young man swallowed a small part of a mouthful of diquat. Diarrhoea, difficulty in swallowing, two small ulcers on the tongue and pharynx and general malaise were the only immediate effects, but because of previous experience with paraquat poisoning, forced diuresis was started. This was continued for