But in other cases, they result in even more toxic secondary pollutants.

但在其他的情况下，会产生毒性更强的衍生性污染物。

Since the advent of cars, another secondary pollutant has taken center stage.

从汽车出现以来，硫酸盐污染物的风头就被另一种衍生性污染物抢走了。

VOCs and nitrous oxide react with sunlight to produce secondary pollutants called PANs and tropospheric, or ground level, ozone.

VOC 和一氧化二氮与阳光发生反应，产生称为 PAN 的二次污染物和对流层或地面臭氧。

Secondary pollutants found in photochemical smog can damage and weaken crops and decrease yield, making them more susceptible to insects.

光化学烟雾中发现的二次污染物会破坏和削弱农作物并降低产量，使它们更容易受到昆虫的侵害。