토양살충제인 phorate를 포장에 살포한 후, 토성이 다른 두 지역의 소형시험구$(120;cm{ imes}120;cm)$에서 호우(20 mm/hour) 및 세우(5 mm/hour) 조건의 인공강우에 의한 유출농도와 유출율을 측정하였으며, phorate의 유출 농도가 수서생물에 미치는 영향을 파악하기 위하여 유출수를 이용한 송사리에 대한 급성독성실험을 수행하였다. Phorate의 유출정도는 호우 및 세우조건에 따른 차이가 크지 않았고, 양토 및 사양토에서의 평균 유출농도는 각각 11.3 ppb 및 4.8 ppb였으며, 평균유출율은 0.50%이었는데, 양토지역에서 호우시 1.31%, 세우시 0.18%, 사양토지역에서 호우시 0.48%, 세우시 0.012%였으며, 양토지역에서 phorate 유출수를 54.4%로 희석하였을 때 송사리에 대한 급성독성치(96시간 $LC_{50}$)가 관찰되었고, 사양토지역의 유출수는 그 자체로도 50% 이상의 치사가 나타나지 않을 정도로 양토지역보다 독성이 낮았다.
Runoff of phorate, soil insecticide, were measured under simulated rainfall conditions in field using small test plot$(120;cm{ imes}120;cm)$ at the loam area and loamy sand area. Fish acute toxicity tests were performed with runoff water to elucidate its toxicological effect on organisms in ecosystem. The average concentrations of phorate in runoff water from loam and loamy sand soil were 11.3 ppb and 4.8 ppb, respectively. However, there was no significant concentration difference between the heavy and the light rain. With loam soil, average runoff rates were 1.31 and 0.18%, while with loamy sand soil those were 0.48 and 0.012% under the heavy and the light rain conditions, respectively. Total average runoff rate was 0.50%. With killifish, no mortality was observed in runoff water from loamy sand soil, whereas half of the population was dead in runoff water from loam soil when it was diluted to 54.4% content.
