Chemicalpollution will bring about a threat to agriculture and food chain, and consequently to human health.
化学污染将威胁农业和食物链，进而危害人类健康。
2
This chemicalpollution has two sources: the factories which dump polluted water directly into the river and the local community which dumps untreated human wastes into the river.
这种化学污染有两个来源：直接把污水倒进河里的工厂，和把未经处理的人类垃圾倒进河里的本地社区。
3
Because of the above reasons stratospheric more easily than the troposphere by chemicalpollution.