United Graduate School of Agricultural Sciences, Kagoshima University, Kagoshima City, Kagoshima, Japan.
Arch Environ Contam Toxicol. 2010 Feb;58(2):352-60. doi: 10.1007/s00244-009-9364-1. Epub 2009 Jul 17.
This paper presents the occurrence, distribution, and environmental impact of pesticide residues in coastal water in southern Japan that receives effluents from a wastewater reservoir temporarily storing surface runoffs of rice paddy fields located near the coastline during the 2005 rice planting season. Concentrations of 14 target pesticides were measured by GC-MS and the hazards posed by the most important pesticides detected were evaluated by acute toxicity tests using a marine diatom, Chaetoceros sp., and a marine amphipod, Hyale barbicornis. Six pesticides (fenobucarb, flutolanil, iprobenfos, mefenacet, phthalide, pyriproxyfen) were detected in the coastal water, with three pesticides (fenobucarb, iprobenfos, and mefenacet) having 100% frequencies of detection. The maximum concentration of mefenacet, at 4.22 microg/L, was at least one magnitude higher than that of fenobucarb and iprobenfos, at 0.27 and 0.19 microg/L, respectively, while the three remaining pesticides had concentrations just around the detection limit of 0.01 microg/L. Consequently, detected concentrations of mefenacet were highly correlated with salinity levels, confirming that the wastewater reservoir is a major source of rice pesticide residues in this particular coastal environment. Hence, the spatial distribution of mefenacet was simulated using their relationship and the results indicate that mefenacet has a tendency to enter and spread to a relatively wide portion of the coastal area during the rice planting season. There is also a possibility that the other pesticides used in rice farming such as fenobucarb and iprobenfos may show similar distribution patterns in coastal waters when they are present in the wastewater reservoir at higher concentrations. These pesticides, however, manifested low acute toxicities to both Chaetoceros sp. and H. barbicornis, suggesting little impact to marine organisms.
本论文介绍了日本南部沿海地区农药残留的发生、分布及其环境影响。该地区的沿海水域受到来自一个废水水库的影响，该水库在 2005 年水稻种植季节期间临时储存来自沿海稻田的地表径流。通过 GC-MS 测量了 14 种目标农药的浓度，并使用海洋硅藻 Chaetoceros sp. 和海洋桡足类 Hyale barbicornis 进行急性毒性试验评估了检测到的最重要农药的危害。在沿海水中检测到 6 种农药（苯硫威、氟唑菌酰胺、丙硫磷、甲萘威、邻苯二甲酸酐、吡虫丙醚），其中 3 种农药（苯硫威、丙硫磷和甲萘威）的检出率为 100%。甲萘威的最高浓度为 4.22 微克/升，至少比苯硫威和丙硫磷高一个数量级，分别为 0.27 和 0.19 微克/升，而其余三种农药的浓度刚好在 0.01 微克/升的检测限左右。因此，甲萘威的检出浓度与盐度水平高度相关，证实废水库是该特定沿海环境中水稻农药残留的主要来源。因此，使用它们之间的关系模拟了甲萘威的空间分布，结果表明，在水稻种植季节期间，甲萘威有进入并扩散到沿海地区较宽部分的趋势。在废水库中存在更高浓度的情况下，用于水稻种植的其他农药，如苯硫威和丙硫磷，也可能在沿海水域表现出类似的分布模式。然而，这些农药对 Chaetoceros sp. 和 H. barbicornis 的急性毒性较低，表明对海洋生物的影响很小。
