一、现代环境的特点自从二次大战以后,环境污染问题日益严重,目前世界环境存在如下一些特点: 1.化学性污染大量增加:据美国《化学文摘》登记的化学品编号已达500万种之多,进入人类环境的约有96,000种,其中如石棉,1930年美国只生产50万吨,到1970年生产5,000万吨,增加了100倍;有机物在1940年只合成190万吨,到1977年增加到3.6亿吨,增加了180倍。有人估计西方国家每人每年通过饮食摄入的化学添加剂就有1500 g左右。 2.高度稳定的化学物进入环境:许多人工合成的化学物半减期极长,有的甚至不能被 First, the characteristics of the modern environment Since the Second World War, the problem of environmental pollution is worsening, the current world environment has the following characteristics: 1. A substantial increase in chemical pollution: according to the United States, “Chemical Abstracts,” registered chemical number has reached 5 million As many as 96,000 species entered the human environment. Among them, asbestos, the United States produced only 500,000 tons in 1930 and 50 million tons in 1970, an increase of 100 times. In 1940, only 1.9 million tons of organic compounds were synthesized, and by 1977 The annual increase to 360 million tons, an increase of 180 times. Some people estimate that there are about 1500 g of chemical additives that are consumed by people in the Western countries each year through their diet. 2. Highly stable chemicals enter the environment: Many synthetic chemicals have a very long half-life, and some can not even be