The concentration of pesticide that was inspired by speed sprayer (SS) operatorsin spraying a low toxic organophosphorus pesticide (800-fold to 1000-fold dilutions of wettable agent) were measured by the impinger-one respirator-per man measuring system. The mean ± standard error was 0.01116 ± 0.00191 mg/m³.
The operators were made to perform the spraying task every day, and the organophosphorus pesticide concentration in the serum was gas-chromatographically measured before and after the task on each day. The maximum concentration after daily task was 0.032μg/2ml in an operator, and 0.061μg/2ml in anassistant. The concentration was already trace or undetectable in many of them the following morning. No apparent tendency for the pesticide to be accumulated was observed even in the operators after spraying the pesticide for 2 consecutivedays.
The 24-hour urine was collected from each subject to measure the outputof PNMC (p-nitro-m-crezol). The output tended to be greater in the assistants than in the operators. This finding may be attributed to the fact that the assistants are trasiently exposed to high concentrations of the pesticide in powder form.

In application of organophosphorus pesticides (800-fold dilution of Sumithion and 1500-fold dilution of Diazinon) for the control of disease and insect damages to apples, the amount of exposure to the pesticides, blood levels of the pesticides, and liver function tests of the workers engaging in the application work were observed. Its summary was as follows;
1. The concentration of pesticides inhaled by each worker engaging in the fixed piping joint control was calculated as 0.030±0.042mg/m³ (mean±S. E.).
2 Analysis of the correlation between the inhaled amounts of pesticides and the air velocity disclosed that was a statistically significant positive correlation between the two parameters. Therefore, it will be necessary for the workers engaging in the application of pesticides to amply consider the factor of wind in actual application.
3. Both the serum levels of organophosphorus pesticides and the urinary excretion of p-nitro-m-crezol measured were low.
4. In view of the above-mentioned current amounts of exposure to pesticides, no acute effects of the pesticides were manifest on the liver function tests.
5. However, because the fixed piping joint control system employs the lance application (hand application), the applicator is more liable to be exosed to large amounts of pesticides, the exposure amount being 2.7 times that of speed sprayer (SS) operator.
6. It is not rare that women and the aged engage in the fixed piping joint control; therefore, it is necessary to educate ample care in the protection of workers from exposure to pesticides.