United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima, Japan.
Environ Monit Assess. 2010 Jan;160(1-4):371-83. doi: 10.1007/s10661-008-0701-z.
Pesticide residues in five freshwater areas that are directly affected by rice paddy effluents in southern Japan were measured to determine their maximum concentrations and temporal variations. Water samples were collected every week during the 2005 rice planting season in Kagoshima Prefecture and stations were established in Amori River, Sudo River, Nagaida River (that drains into the bigger Kotsuki River), rice paddy drainage canal, and wastewater reservoir (that collects effluents from rice paddy fields). Of the 14 target pesticides examined, a total of 11 were detected in all stations. Mefenacet, fenobucarb, and flutolanil were the three pesticides with the highest maximum concentrations and were also detected frequently. Analysis of temporal variations of pesticides showed that herbicides had relatively higher concentrations in the earlier stages of the rice planting season, while insecticides and fungicides had relatively higher concentrations at the later stages. There was no significant difference among stations with regards to the temporal patterns of the top three pesticides. The calculated toxic units were less than 1 in all stations, implying low or negligible environmental risk of pesticides detected to freshwater organisms.
本研究测定了日本南部受稻田污水直接影响的五个淡水区域的农药残留，以确定其最大浓度和时间变化。在鹿儿岛县 2005 年水稻种植季节期间，每周采集水样，并在天草川、须藤川、永田川（流入更大的琴平川）、稻田排水渠和废水库（收集稻田污水）设立了采样点。在所检查的 14 种目标农药中，所有站点均检测到了 11 种农药。甲酰胺、苯丁锡和氟噻唑吡乙酮是浓度最高的三种农药，且经常被检出。对农药时间变化的分析表明，除草剂在水稻种植季节的早期浓度较高，而杀虫剂和杀菌剂在后期浓度较高。三个主要农药在各采样点的时间模式上没有显著差异。在所有采样点，计算出的毒性单位均小于 1，表明检测到的农药对淡水生物的环境风险较低或可忽略不计。
