is my top concern 的演讲稿

我以前也做过类似的演讲,这些是我找的资料,你可以把资料串起来就成了演讲稿.
水污染定义
Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans and groundwater).
Water pollution affects plants and organisms living in these bodies of water; and, in almost all cases the effect is damaging not only to individual species and populations, but also to the natural biological communities.
Water pollution occurs when pollutants are discharged directly or indirectly into water bodies without adequate treatment to remove harmful compounds.
以下是一些现状,每点之间没什么太大联系,看你自己怎么取舍.
Water pollution is a major problem in the global context. It has been suggested that it is the leading worldwide cause of deaths and diseases, and that it accounts for the deaths of more than 14,000 people daily.
Some 90% of China's cities suffer from some degree of water pollution, and nearly 500 million people lack access to safe drinking water.
In the most recent national report on water quality in the United States, 45 percent of assessed stream miles, 47 percent of assessed lake acres, and 32 percent of assessed bay and estuarine square miles were classified as polluted.
水污染原因
The specific contaminants leading to pollution in water include a wide spectrum of chemicals, pathogens, and physical or sensory changes such as elevated temperature and discoloration. Many of the chemical substances are toxic. Subsequent negative environmental effects such as anoxia (oxygen depletion) and severe reductions in water quality may occur, affecting fish and other animal populations.