SSS 2008-04-21(在线收听

This is Scientific American’s 60-Second Science. I’m Adam Hinterthuer. Got a minute?

 You’ve probably heard about mercury contamination in fish. But a new study says that the toxin has climbed out of the water. Researchers from the College of William & Mary say landlubbing insects near the Shenandoah River have elevated levels of mercury in their blood, and so do the birds that eat them. The report appears in the April 18th issue of the journal Science. The scientists tested mercury in 13 insect-eating bird/ species and found that 12 had dangerously higher levels. They then examined the birds’ food supply-literally snatching spiders, moths and grasshoppers out of the mouths of babies in their nests. These tasty morsels all contained mercury. And spiders which sit higher up the insect food chain had even more mercury than fish collected from the river. The news is alarming since mercury can cause reproductive failure and even death at low  concentrations. The researchers now want to know how a problem thought to be confined to a single ecosystem is spreading. They speculate that contaminated aquatic insects or maybe polluted floodwaters are helping mercury creep out of the river and take to the wing.

 

Thanks for the minute for Scientific American’s 60-Second Science. I’m Adam Hinterthuer.

 

  原文地址:http://www.tingroom.com/lesson/sasss/2008/4/98652.html