Field study on a role of particulate matter in transportation of micropollutants in aquatic environments

1.通过全年调查，明确了水库、进水和输水渠道水常规水质、农用化学品浓度和致突变性(Ames试验)的季节变化。在可溶相样品中，5~8月河水的直接致突变性和间接致突变性有时为阳性或准阳性，而对河道和水库水的直接致突变性和间接致突变性常年均为阴性。颗粒相样品对航道水的直接致突变性和间接致突变性大多为阴性，而对河流和水库水的间接致突变性有时呈准阳性。一些农用化学物质主要在水稻种植季节检出。几乎没有检测到吸附在颗粒物上的农用化学品。农用化学品与致突变性之间的关系尚不清楚。对雨天和雪天的河水以及森林径流进行了调查。部分颗粒相样品的致突变性随流量的增加呈准正值，但随时间变化较大。虽然3月份在河水中的可溶相样品中检测到除草剂异丙草胺，但致突变性为阴性。对降雨量和降雪量进行了全年调查。在可溶相样品中，11-2月的致突变性大多为阳性，5-9月为阴性或弱致突变性。其致突变性有因代谢活化而减弱的趋势。在颗粒物相样品中，致突变性大多为负，但在冬季有时为正。认为引起阳性致突变性的物质可能是多环芳烃和硝基多环芳烃。这些结果表明，在径流过程中，降水中的可溶性直接致突变剂发生分解或转化，并被吸附到土壤上，然后吸附的致突变剂随侵蚀土壤流出或向下流动。

1. Seasonal changes in conventional water qualities, agrochemicals concentration and mutagenicity (the Ames test) of reservoir, influent river and conveyance channel water were made clear through year-round surveys. In the soluble phase samples direct and indirect mutagenicity were sometimes positive or quasi-positive for the river water from May to August but mostly negative for the channel and reservoir water all year round. In the particulate phase samples direct and indirect mutagenicity were mostly negative for the channel water, whereas indirect mutagenicity was sometimes quasi-positive for the river and reservoir water. Some kinds of agrochemicals were detected mainly during the rice-planting season. Few kinds of agrochemicals adsorbed on particulate matter were detected. The relation between mutagenicity and agrochemicals was not clear.2. Surveys were carried out for the river water during rainy or snowy days as well as the runoff water from forest. In some of the particulate phase samples mutagenicity was quasi-positive when the water flow increased, but the temporal variation was large. Although pretilachlor, one of herbicides, was detected in the soluble phase samples of the river water in March, mutagenicity was negative.3. A year-round survey was performed for rainfall and snowfall. In the soluble phase samples mutagenicity was mostly positive from November to February but negative or weak from May to September. Mutagenicity showed a tendency to become weak by the metabolic activation. In the particulate phase samples mutagenicity was mostly negative but sometimes positive in winter. It is considered that substances which caused positive mutagenicity might be PAHs and nitroPAHs.4. These results suggest that soluble direct mutagens in the precipitation were decomposed or changed and soluble indirect mutagens were adsorbed onto the soil during the runoff process, and then, the adsorbed mutagens flowed out and down with the eroded soil.