Impacts of nanosilver on a lake ecosystem

纳米技术有可能应用于几乎每一个经济部门，包括消费品、农业、生物医学、运输和能源。虽然纳米技术有可能产生社会效益，但更好地了解纳米材料释放到环境中的生态风险，包括对生态服务的影响，应该是一个优先事项。我们之前的实验室研究表明，水生环境中的NMs首先影响食物链底部的生物，包括细菌、藻类和浮游动物。这些反应可能通过降低总体生产力和改变养分循环对水生生态系统产生破坏性影响。水生生态系统中可能存在缓解这些反应的补偿机制，但不可能通过实验室研究来预测这些反应。我们建议在安大略省西北部的实验湖区（ELA）进行一项研究，在两个野外季节向一个小湖泊中添加纳米银。纳米银是一种广泛使用的纳米材料，被用作数百种产品的杀菌剂，包括手术绷带、食品包装、婴儿奶瓶、拖鞋、袜子、内衣、鞋垫，甚至洗衣机。纳米银将每天在湖岸的一个地方添加，以模拟废水处理厂的点源输入，我们将沿着暴露梯度监测湖泊的营养循环变化和湖泊食物链中的生物效应。然而，在开始添加银之前，我们将通过确定在湖泊中部署的中生态系统（即塑料管）中发生的情况来改进我们的方法。四十多年来，ELA一直被用作研究污染物对环境影响的活实验室，包括过去对磷、酸沉积、汞和内分泌干扰物污染影响的研究。虽然我们不能轻视纳米银对ELA研究湖的潜在影响，但这种方法是确定生态系统水平影响的唯一方法。反过来，这些信息将影响监管政策，以限制NMs释放到环境中的生态风险。

There is potential to apply nanotechnology to almost every economic sector, including consumer products, agriculture, biomedical, transportation and energy. While nanotechnology has the potential to produce societal benefits, it should be a priority to better understand the ecological risks from the release of nanomaterials (NMs) into the environment, including impacts upon ecological services. Our previous laboratory research has shown that NMs in the aquatic environment first affect organisms at the bottom of the food chain, including bacteria, algae and zooplankton. These responses may have devastating effects upon aquatic ecosystems by reducing overall productivity and altering the cycling of nutrients. There maybe compensatory mechanisms within aquatic ecosystems that mitigate these responses, but it is impossible to predict these responses using laboratory studies. We propose to conduct a study at the Experimental Lakes Area (ELA) in northwestern Ontario by adding nanoform silver to a small lake over two field seasons. Nano-silver is a widely used NM that is used as a bacteriocide in hundreds of products, including surgical bandages, food wrappers, baby bottles, slippers, socks, underwear, shoe-liners and even in washing machines. The nanoform silver will be added daily at a location along the lakeshore to simulate point source inputs from a wastewater treatment plant, and we will monitor the lake along an exposure gradient for changes to nutrient cycling and biological effects within the lake food chain. However, before starting the additions of silver, we will refine our approach by determining what happens in mesocosms (i.e. plastic tubes) that are deployed in lakes. ELA has been used for over 40 years as a living laboratory to study the effects of pollutants in the environment, including past studies of the impacts of pollution from phosphorus, acid deposition, mercury and endocrine disruptors. While we do not take lightly the potential impacts of nano-silver on the study lake in ELA, this approach is the only way to determine ecosystem level impacts. In turn, this information will influence regulatory policy to limit the ecological risks from the release of NMs into the environment.