DIELDRINの慢性毒性 : とくに羊毛防虫加工剤としての毒性に関する実験的研究
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The principal component of Dieldrin is the endo-isomer of 1,2,3,4,10, 10-hexachloro-6, 7-epoxy-1,4,4a,5,6,7,8, 8a-octahydro-1,4,5,8 dimethano-naphthalene, commonly abbreviated to HEOD. This chemical has been widely used all over the world as an insecticide in agriculture and public health and, in Japan, it was approved as an insecticide for environmental sanitation by the Ministry of Health and Welfare in 1956. Recently, Dieldrin has been newly developed in the field of mothproofing of wool (M. Lipson,). Mothproofing with Dieldrin is very inexpensive as well as being remarkably effective, even at a low concentration. Although Dieldrin is considered to be almost ideal as a mothproofer, there are few reports on its toxicity as a mothproofing agent. This problem must be solved before discussing any hazard in its practical usage such as could be caused by dermal absorption from underwear, babies' sucking a part of their clothing etc. This is the basis and object of these experiments. Part I. Acute and Chronic Toxicity to Albino Rats. 1. Acnte oral toxicity of technical dieldrin (HEOD 85%) to albino rats was 39.5 mg/kg, and that of recrystallised dieldrin used in mothproofing (HEOD 96%) was 66 mg/kg which is about 50% lower than the former. 2. When rats were reared with woollen yarn impregnated witd 96% HEOD at 0.1% and 0.2% for 80 days, there was no change to the increase in body weight nor any increase in liver weight. At 0.5% and 1%, inhibition of growth was observed and at 3% and 5% rats were killed in a few days. 3. In the experiment in which an acetone solution containing 96% HEOD was applied to the skin of rats every day for 49 days, the inhibition of body weight increase was observed in the 5 and 10 mg/kg groups and the ratio of liver weight to body weight increased in the 10 mg/kg group. 4. The liver weight also increased in the orally administered group. 5. When the function of the liver is deducted from the increase of coproporphyrin in the urine, strong positive reaction increased in groups reared in knitting yarn treated at 1% (refined dieldrin) and over, and in the dermal application group and oral application groups at 5 mg/kg/day and above. With Mitin, all rats showed strong positive reaction from consuming 0.1% solution (about 100 mg/kg), and even at 0.01%, 40% of them showed strong positive reaction. 6. In case of liver hypertrophy, fatty degeneration was observed in histopathological findings. With acute intoxication and death, degeneration of liver cells (swelling and vacuolation) and karyolysis were observed and intense fatty degeneration was proven by Sudan III staining. On the kidney, congestion, karyolosis and swelling of the epithelial cells of the nephritic ducts were observed. 7. The main symptoms of intoxication of rats were excitation, tremor, clonic and tonic convulsions 8. The results of chemical analyses of faeces by the phenylazide method disclosed that dieldrin applied on the skin was partially eliminated into the digestive tract. 9. From the result of the chronic intoxication experiment of 49-92 days duration, it is estimated that the safety limit (threshold limit) for rats will be the absorption of less than 1 mg/kg of refined dieldrin. When the experiment is extended over a long period of time or young rats are involved, it is safer to lower this limit. Part II. Estimation of Absorption from Dieldrin-Impregnated Woollen Yarn Worn by Man and Extraction by Saliva. 1. Averaging 13 mg., maximum 21 mg. of dieldrin was lost when 4 men continually wore dieldrin impregnated woollen shirts (96% HEOD at 0.1%) for 60 days consecutively. If this amount of dieldrin were all absorbed and, additionally at the same rate from similarly treated trousers, the amount of dieldrin absorbed through the skin is estimated to average 0.008 mg/kg/day with a maximum of 0.0128 mg/kg/day. 2. This value is about 1/10 of the safety limit of chronic intoxication for dogs, though the safety coefficient will be larger when the co
- 社団法人日本産業衛生学会の論文
- 1962-12-20