The rate of mortality from paraquat poisoning is high and the principal manifestation of toxicosis is pulmonary impairment.
In this study, we measured the concentration of paraquat in the urine, blood, and some organs in 10 patients with acute paraquat poisoning in order to study the relationships of the kinetics in the body to the concentration in the lungs and to the pulmonary impairment.
The concentration of paraquat dichloride in the blood stream rapidly decreased in the first 24 hours. The half life was about 0.5 hour, within 2 hours (case 3) after intoxication, about 1 hour after 5 hours (case 5), about 2 hours after 10 hours (case 6) and after 24 hours (case 6) was prolonged to over 26 hours.
Therefore, it was suggested that half life was subsequently prolonged with the passage of time.
There were indications that renal disturbance appeared in about 5 hours after oral intake.
Accumulations of paraquat were seen in the organs examined. The largest amount within 24 hours after exposure was recognized in the lungs, and the largest amount after 271 hours was seen in the skeletal muscle. The concentration of paraquat in the lungs was higher than the concentration levels in the blood at death in all the cases.
Although excretion of paraquat from the lungs was very slow. it became faster with DHP and HD. However, excretion from the skeletal muscle was slow, Excretion from the other organs excepting the kidney was considered to be constant, being proportional to the blood concentration levels.
The pathologic examination of the lungs found congestive edema in 6 cases, which became severer with the lapse of time. Partial pulmonary fibrosis was recognized only in long-term survival cases.
The cause of irreversible pulmonary impairment was considered to be the effect of the small amount of paraquat remaining in the lungs which exceeds the concentration in the blood.

By use of 18 varieties of pesticide and six of their breakdown products, experiments were conducted to cause mutation and reversion in S. typhimurium TA98 and TA100 within a range of 0.01ug-100 ug/plate.
The results showed that Captan had mutagenic effects on TA98 and TA100. However, when S-9 mix was added, the number of revertant colonies ceased increasing.
Ethylenthio urea caused mutations in TA98. When S-9 mix was added, revertant colonies increased about twice the number in the control. In the absense of S-9 mix, the result was the same.

Farmers are constantly exposed to the hazards of agrochemicals. Especially those who regularly spray their fields with pesticides are at high risk of being contracted with pesticideinduced maladies.
During the three-year period from 1980 to 1982, health examinations were conducted, covering a total of 1, 164 pesticide sprayers in eight rural communities, Miye Prefecture. Of the number, 869 were women. Mercury residues in hair were also measured.
The findings are as follows:
1. Abnormal lipid metabolism topped the list of disorders, followed by hypertension, ECG abnormalities, anemia, albuminuria and liver dysfunction in that order.
2. The rates of detection of these abnormalities were not particularly high as compared with those in ordinary health checkups.
3. When compared with previous findings, the cases of abnormal lipid metabolism and anemia decreased in number both in men and women, whereas the cases of abnormal cholinesterase activities and albuminuria increased in both sexes.
4. The majority of pesticides used by the farmers were organophosphorous.
5. The average level of mercury residues in hair was 5.35 ppm for men and 2.97 for women. 6. More than 6.0 ppm of mercury were detected in 23.1 % of the men and 1.9% of the women. None were found to carry more than 20 ppm of mercury in their hair.