我们常常将空气污染与烟囱和汽车联系在一起，但事实上火山、森林火灾、沙暴、沼泽、海洋和植物都会带来一些我们认为是大气污染物的化学物质。
We normally associate air pollution with smokestacks and cars, but volcanoes, forest fires, dust storms, marshes, oceans, and plants also add to the air chemicals we consider pollutants.
但调查资料表明室内空气污染比室外大气污染更为严重。
The effects of outdoor air pollution on health have received more attention than those of outdoor air.
预防是另一种控制空气污染的关键手段。如上文所述，管理机构在减轻和预防环境大气污染中起着关键的作用。
Prevention is another key to controlling air pollution. The regulatory agencies mentioned above play an essential role in reducing and preventing air pollution in the environment.
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