英语听力文摘 English Digest 416、“二手”空气（在线收听）

“二手”空气

        Big cities, with all their pollution, have an effect on trees……

No doubt.

In the countryside.

Say what? Big cities affect the trees in the countryside?

You got it! According to a study conducted by Jillian Gregg, who now works at the EPA’s western-ecology division in Oregon, Eastern Cottonwood trees grew twice as big inside the Bronx as they did growing in small towns on Long Island.

But that just seems backwards. Cities are where all pollution, should that hamper the growth of the trees?

Cities are full of pollution, and it does have a detrimental effect on plant life–to say nothing of people life! But that doesn’t mean, unfortunately, that the converse is true –that once you get outside of the city, the environment is clean.

Regions can suffer from pollution that blows in from the cities and then lingers around the countryside. In particular, ozone does this.

Second-hand ozone?
Indeed, Gregg’s study, along with others, are fingering ozone as the factor that most significantly affects plant growth.

So Cities make the pollution but it blows over the countryside and hurts trees there instead. That seems so unfair.

It’s just another warning about the surprising effects of pollution–and how we all suffer from it, even when we think it’s someone else’s problem.

大都市的环境污染对树有影响……

毫无疑。

……影响农村的树……

你说什么？大都市的环境污染对农村的树有影响？

没错！一项由Jillian Gregg发起的研究表明，在布朗克斯生长的美洲黑杨比小镇纽约长岛的高大两倍，Jillian Greg在美国环保署西部生态分署的俄勒冈州工作。

我怎么觉得好像说反了，城市污染严重，就会影响到农村树木的生长吗？

城市的环境污染确实有害植物生长，更不要说人的生活了。但是不幸的是，这并不能说明相反的是对的：远离城市的环境就是无污染的。

城市的污染会从城市扩散到农村，特别是污染农村的新鲜空气。
“二手”新鲜空气？

事实上，Greg和其他人的研究都指出影响植物生长的就是空气被污染了。

也就是说城市是污染的源头，又扩散到农村，还不利农村树木的生长，听起来太不公平了。

这可能是另一个有关环境污染出人意料的影响：虽然我们认为环境污染不是自己的问题，但是我们都承受着其带来的不良后果。