EXPERIMENTAL STUDIES ON THE TOXICITY OF BENZENE HEXACHLORIDE (BHC) AND DICHLORODIPHENYLTRICHLOROETHANE (DDT)II. TOXICITY TESTS BY THE DUST INHALATION OF THE INSECTICIDES TO LABORATORY ANIMALS

摘要

Summarizing the above mentioned experimental results, in the inhalation group of BHC powder, the rats showed symptoms of temporary excitability, eye hemorrhage and excess secretion of nasal mucous. Except a youngest and smallest of the 6 rats which died of convulsions, the remaining 5 rats survived and were not poisoned.The symptoms of mice were the same toxic symptoms accompanying each administration as was described in the first report. Slight tremors were observed and remarkable convulsions caused the younger ones to die early.In the DDT group, the symptoms of the mice showed the same results as the foregoing administrations. Severe tremors appeared and at last death resulted with convulsions.According to these results, it was shown that the inhalation of BHC and DDT powder was toxic to laboratory animals.Concerning the dust inhalation tests, the first problem is to be undeniable about the injurious effects of the inhaled powder dust itself.On the effects of powder or dust for living bodies are reported too many to enumerate, but in short they are: (1) intoxications or allergic diseases, (2) mucous diseases, (3) pulmonary diseases, (4) dissemination of infectious diseases and (5) der-matological diseases.The conditions which control the noxiousness of the dust are: (1) the size of the dust particles, (2) number, (3) hardness, (4) shape, (5) solubility, (6) electric chargeabilty, (7) deep-reaching action, and (8) chemical reaction and ingredient. Under these conditions the influences to living body varies greatly in degree.The atmospheric dusts enter into the body through the nose, mouth and throat. However, the skin and the mucous membrane are also concerned with that.When the dusts are inhaled, by the filtering function or self protective function of the body the dusts are discharged out of the body. When the bodies are forced to inhale an excessive quantity of dust, these self-protective functions gradually decline and the influence of the dust increases.Thus the results are that when the powder is inhaled into the lungs the soluble particles are dissolved into the humours of the surface of the alveoles and insoluble ones are stuck on the surface or are caught by the cells and entered into the organs, stimulated them, and caused inflammations and other changes.According to the author's experiments, in the inhalion test of BHC and DDT powder, remarkable specific toxic symptoms of BHC and DDT were caused by the inhalation and the changes were confirmed histopathologically. That is, the changes of the lung due to the inhalation of both powders were alveolar pneumonia and catarrhal pneumonia, in addition to emphysema, atelektasis, and hemorrhage.The effects of various dusts upon the lung and its histologic.al findings are agreed to by many research workers in the past. The changes of the lung in this test and the effects of the dust itself are not denied.As to the histological findings about the effects upon other organs than the lungs, both BHC and DDT powder showed toxicological changes in the liver and the spleen. Thus it is understood that these changes are not caused by the dusts alone. Each constituent of BHC and DDT, the organic compounds contained in the dust, are absorbed and the toxicity appears.Létard and Sacy (1945) reported that when the powder containing 3% BHC was sprinkled over the cornea of rabbits eye for 5 days, eye mucous membranes and nose mucous membranes did not show any symptom nor were tears recognized.According to the author's experiment, many lacrimations and eye hemorrhages were noticed in the rats exposed to the dusts. Consequently these symptoms seem to depend on the stimuli to eye mucous membranes.Moreover, Uruno et al. (1949) did a minute physical examination of the workers (male 94, female 41) of the DDT manufacturing industry and found that about 1/3 of the workers suffered from functional disorders of the liver.