Determination of 3,5,6-trichloro-2-pyridinol levels in the urine of termite control workers using chlorpyrifos.

Chlorpyrifos, an organophosphorus insecticide, has been used to control termites since regulatory measures against the use of chlordanes were taken in September, 1986. We developed an improved gas chromatographic (GC) method for the assay of 3,5,6-trichloro-2-pyridinol (TCP) in the urine to use in the biological monitoring of exposure to chlorpyrifos. Urinary TCP was separated and determined accurately (C.V., 4%) with high sensitivity (detection limit, 10 ng/ml) and recovery (recovery greater than 90%) using a wide bore capillary column (WBC column). The accuracy and precision of the present GC method are satisfactory. The time course of urinary excretion of TCP was followed in workers. The urinary TCP level was low in the off-season and high in the busy season. Variation in the urinary TCP level corresponded to the termite control season and the length of the working period. The urinary TCP level showed a change reciprocal to the variations in the plasma cholinesterase activity. From these results, it is surmised that the urinary TCP level represents the extent of exposure to chlorpyrifos. The decrease in the level of cholinesterase activity is suggested to be due to exposure to chlorpyrifos. Determination of the urinary TCP level by GC using a WBC column is useful in the biological monitoring of chlorpyrifos in termite control workers and potentially has practical application to health care.</p

Variations in blood cholinesterase activity level in termite control workers using chlorpyrifos

1986年9月よりシロアリ防除剤として広く使用されだしたクロルピリホス(有機リン系殺虫剤)のシロアリ防除作業者への健康影響を明らかにするために,シロアリ防除事業所の従業員8名について追跡調査を行い,以下の結果を得た. 1.処理作業従事者(6名)の毎月初めの平均血漿コリンエステラーゼ活性値は1987年4月までは正常範囲であったが,シロアリ防除シーズン(繁忙期)の5月より低下を始め, 6月～9月は正常値の下限(0.6ΔpH)以下であった.その後閑散期には回復に向かい, 1988年1月にはシーズン前の水準に戻った.各作業者においては,シーズン中の最低値は,シーズン前の水準(1986年11月～1987年4月の各人の平均値)の50%以下であり,うち2名は10%以下にまで低下した.一方,主として営業従事者の2名の血漿コリンエステラーゼ活性値はシーズン中にやや低下したものの正常値の範囲内であり,シーズン中の最低値もシーズン前の水準の60%以上であった. 2.赤血球コリンエステラーゼ活性値は, 1987年6月から1988年1月まで8名とも正常範囲であったが, 6～9月は低く, 12月及び翌年の1月は高値であった.前者の期間における各人の平均値の後者の期間における各人の平均値に対する割合は, 8人の平均で72.2%であった. 3. 1作業者の観察において,シーズン中の処理作業従事時間数と血漿コリンエステラーゼ活性値の増加率との間には有意の負の相関が認められ, 1日の時間数が2時間で血漿コリンエステラーゼ活性値は横這い,それ以上で低下,それ以下で上昇することが明らかになった. 4.作業者の自覚症状,他覚症状には顕著な異常は認められていない.作業者によっでは赤血球数および白血球数の若干の低下,血清脂質およびリパーゼの異常等が認められており継続観察の必要がある. 5.血漿コリンエステラーゼ活性値はクロルピリホスの生物学的暴露指標として鋭敏であり,クロルピリホスによる健康障害の予防のために有用である.In order to clarify the effect of chlorpyrifos on workers using chlorpyrifos for termite control, changes in the cholinesterase activity in the blood of 6 workers was surveyed. Cholinesterase activity in the plasma and erythrocytes decreased in the busy season from May to September and recovered in the off season of January. The ratio of the lowest level of plasma cholinesterase activity from a worker in the busy season to the average activities of a worker examined several times in the off season, was examined in each workers. The ratio was under 50% in 6 workers using chlorpyrifos. The ratio of the mean cholinesterase activity in the erythrocytes of a worker in the busy season to that in the off season was examined, and was about 70% in 6 workers. A negative correlation between working time and increasing ratio of plasma cholinesterase was significant. A marked change in the subjective and objective symptoms of workers was not absent in busy season. Although some workers showed a decrease in the number of erythrocytes and leukocytes, and an increase in serum lipase activities, and abnormalities in the serum lipids. The data indicated that plasma cholinesterase activity levels are useful for biological exposure monitoring of chlorpyrifos

Medical service situation by city and town: A classification attempt using principal component analysis - On out-patient medical treatment in 43 cities and towns of Kagawa Prefecture -

The medical service situation of out-patient medical treatment in 43 cities and towns of Kagawa Prefecture was analyzed, and classified using principal component analysis. When viewed by the average of 43 cities and towns, the rate of dependence on one's own area was 48.4%, the rate of patients from one's own area at 73.3%. Generally, the self-sufficiency of medicalcare was high, and the medical treatment zone was wider in the city region compared with the county region. The medical service situation in 43 cities and towns was classified into 5 types such as the Nuclear type: 4 cities; the Base type: 1 city and 4 towns; the Averageother type: 18 towns; the Peripheral type (the Insular region type: 3 towns; the Peninsular or remote place type: 2 towns; the Satellite city type: 2 towns) and the Depopulated type: 9 towns, using principal component analysis with the rate of dependence on one's own area, rate of patients from one's own area, dependence entropy and medical treatment zone entropy as the input data