科学美国人60秒 用蜻蜓来探测汞污染（在线收听）

This is Scientific American's 60-second Science, I'm Berly McCoy.

这里是科学美国人——60秒科学系列，我是伯利·麦考伊。

Mercury pollution from power plants and mining operations can end up in our air and water.

发电厂和采矿作业产生的汞污染最终会进入我们的空气和水中。

But it’s tricky to predict just how much of that environmental mercury will make its way into our food—and our bodies.

但很难预测有多少环境汞会进入我们的食物和身体中。

“We were working on developing a bioindicator, a BioSentinel, that could inform us of the levels of mercury contamination across the U.S.”

“我们正在开发一种生物指示器，相当于一个BioSentinel(卫星)，它可以让我们知道美国各地的汞污染水平。”

Ecologist Collin Eagles-Smith of the United States Geological Survey.

美国地质调查局的生态学家科林·伊格尔斯-史密斯说。

He and his colleagues came up with a practical way to determine the scope of mercury contamination in an ecosystem by measuring mercury levels in a single species.

他和他的同事们想出了一种实用的方法，通过测量单一物种的汞水平来确定生态系统中汞污染的范围。

Their bioindicator: juvenile dragonflies, or larvae.

他们的生物指示器是: 幼蜻蜓或者蜻蜓幼虫。

Dragonfly larvae stay underwater, don’t move much, are easy to collect and live long enough to accumulate significant amounts of mercury.

蜻蜓幼虫呆在水下，不怎么会移动，很容易收集，而且活得时间足够长，可以收集大量的汞。

“If you have enough locations sampled with dragonflies, you can develop an index of the relative amount of mercury in the biological community.”

“如果你有足够多的蜻蜓样本，你就可以建立一个生物群落中关于汞相对含量的指数。”

The team measured mercury concentrations in thousands of dragonfly larvae collected from waterways in 100 national parks during a 10-year period.

该团队在10年的时间里，从100个国家公园的水道中收集了数千只蜻蜓幼虫，对它们体内的汞浓度进行了测量。

And to amass the large sample number, they recruited volunteers through the Dragonfly Mercury Project.

他们为了收集大量样本，通过“蜻蜓水银计划”招募了志愿者。

The volunteers used dip nets to collect dragonfly larvae from their aquatic abodes.

志愿者们使用水中采集网从它们生活的水上栖息地收集蜻蜓幼虫。

National park staff then sent the larvae to laboratories for processing.

国家公园的工作人员随后将这些幼虫送到实验室进行处理。

For comparison, the researchers also measured mercury concentrations in other aquatic organisms.

研究人员为了进行比较，还测量了其他水生生物中的汞浓度。

“Using the relationships between dragonfly concentrations and fish concentrations, we were able to develop what we call an impairment index.”

“利用蜻蜓的汞浓度和鱼类的汞浓度之间的关系，我们能够研究出我们所说的危害指数。”

That index allowed the researchers to make health risk predictions at each sample site.

该指数允许研究人员对每个样本点进行健康风险预测。

“About 12 percent of the locations posed what we consider to be high or severe risk of health impairments to fish, wildlife or humans if they consumed organisms from those locations.

“大约12%的地点对鱼类、野生动物或人类构成了我们认为的高(严重)的健康危害风险，如果他们食用来自这些地点的生物。

You can begin to build models that are predictive of of how much mercury might be in the system based on the landscape characteristics and the water chemistry and then apply that model to locations where you haven’t sampled dragonflies.

你可以开始建立模型，根据景观特征和水中化学成分来预测系统中的汞含量，然后把这个模型应用到你没有对蜻蜓取样的地方。

“And that can inform future management actions either to address the factors that are promoting the mercury production

这可以为未来的管理行动提供信息，以解决促进汞生产的因素

or simply to inform agencies that may want to evaluate whether or not fish consumption advisories are warranted.”

或者仅仅是让那些想要评估鱼类消费建议是否有必要的机构知道这一信息。”

The study is in the journal of Environmental Science & Technology.

这项研究发表在《环境科学与技术》杂志上。

If you’d like to get involved in the Dragonfly Mercury Project or to see a map of mercury concentrations across the U.S., search for the Dragonfly Mercury Project at nps.gov.

如果你想参与“蜻蜓水银计划”或查看美国各地的汞浓度地图，请在nps.gov上搜索“蜻蜓水银计划”

Thanks for listening for Scientific American's 60-second Science. I'm Berly McCoy.

谢谢大家收听科学美国人——60秒科学。我是伯利·麦考伊。