一份关于保护环境的.ppt

To Protect Environment  For the Future
The world is changing all the time .
The environment is getting worse and worse, air pollution and water pollution has killed a number of people.
Worst of all ,people didn’t realize the danger of the pollution.
The water pollution
。
When the waste gas from cars is released, the air is polluted. People breathing in the polluted air can develop respiratory disease. Another factor is that people throw their garbage everywhere. All kinds of garbage not only spoil the splendid environment, but also cause environmental pollution. What's more, industrial pollution also deserves our attention. Wastewater from factories is poured into rivers and this causes water pollution. As a consequence, the greenhouse effect es a problem which needs our immediate caution and how to solve is urgent all over the world.
We do not want to see.
水污染的现状
从全国总体情况看,废水排放量增长速度极快。预计2000年将达666亿吨。城市生活污水总量也不断增加,2000年约达到783亿吨。由于废水处理事低(估计仅为20%~30%),大部分废水未经处理直接或间接排入水体,严重污染了水资源。我国七大水系中近一半河段污染严重,86%的城市河段水质普遍超标。全国被污染水系,比较严重的是淮河、海河、松花江、辽河、长江中下游以及珠江三角洲等工业比较发达地区。河流的城市段污染明显,小河重于大河,北方重于南方。1990年,在被评价的94个河流城市段中,65个受到不同程度的污染,%,污染物主要以氨氮、挥发酚和耗氧有机物为主。据调查,全国有7亿人饮用大肠杆菌超标水,,3500万人饮用硝酸盐超标水。
The air pollution