USDA-Agricultural Research Service, Soil Drainage Research Unit, 590 Woody Hayes Drive, Columbus, Ohio 43210, USA.
J Water Health. 2010 Sep;8(3):577-92. doi: 10.2166/wh.2010.160. Epub 2010 Mar 9.
Headwater streams constitute the majority of watersheds in the United States and many in the midwest have been channelized for agricultural drainage. Public health implications of water chemistry and aquatic insects within channelized and unchannelized headwater streams have not been explored. We sampled water chemistry and aquatic insects in two channelized and two unchannelized headwater streams in central Ohio from December 2005 until November 2008. Maximum concentrations of ammonium, nitrate plus nitrite, and chlorothalonil were greater in channelized streams. Nitrate plus nitrite and atrazine also exceeded drinking water standards more often in channelized streams. Maximum concentrations of simazine and the percentage of times it exceeded the drinking water standards were greater in unchannelized streams. The predicted hazard potential of nutrient and pesticide mixtures was greater in channelized streams. Mosquito abundance did not differ between stream types. Chironomid abundance was greater in channelized streams. Biting dipterans did not exhibit consistent abundance trends and only differed between stream types in the summer and fall. Our results suggest that if whole stream uptake of nutrients and pesticides is minimal in channelized headwater streams then nutrient and pesticide inputs from these streams may impact downstream drinking water sources. Our results also suggest channelized and unchannelized headwater streams are not serving as a significant source of mosquitoes.
美国大多数流域都由源头溪流构成，美国中西部的许多源头溪流已经被渠化，用于农业排水。目前尚未研究过渠化和非渠化源头溪流中的水化学和水生昆虫对公共卫生的影响。我们于 2005 年 12 月至 2008 年 11 月在俄亥俄州中部的两条渠化和两条非渠化源头溪流中采集了水化学和水生昆虫样本。在渠化溪流中，铵、硝酸盐加亚硝酸盐和百菌清的最大浓度更高。硝酸盐加亚硝酸盐和阿特拉津也更频繁地超过了渠化溪流中的饮用水标准。在非渠化溪流中，西玛津的最大浓度和超过饮用水标准的次数百分比更高。营养物质和农药混合物的预测危害潜力在渠化溪流中更大。蚊虫数量在溪流类型之间没有差异。摇蚊在渠化溪流中更为常见。吸血双翅目昆虫的丰度没有一致的变化趋势，仅在夏季和秋季在溪流类型之间存在差异。我们的结果表明，如果渠化源头溪流中整个溪流对养分和农药的吸收最小，那么这些溪流中的养分和农药输入可能会影响下游饮用水源。我们的结果还表明，渠化和非渠化的源头溪流并不是蚊子的重要来源。
