Pesticides, Radiation, and Noise
The use of pesticides has increased world food production and has controlled such human diseases as malaria. However, their widespread and often indiscriminate use has not only killed many harmless or beneficial organisms but has also produced a special type of pollution. It is now known that some of the more persistent pesticides, such as DDT, chlordane, and lindane, accumulate in the tissues of birds, fish, other wildlife, and man. These pesticides have caused cancer, fetal damage, and nerve damage in test animals, and pesticide residues are suspected of causing anemia, sterility, cancer, and brain damage in humans.
Radiation occurs naturally but also can be released from certain things that people have produced. Some radiation, for example, has been released from nuclear reactors that generate electricity and process fuels. Testing of nuclear weapons has also released radiation. Another danger lies in possible accidental leakage from stored radioactive wastes. Health hazards from excessive radiation include cancer, eye damage, and damage to reproductive cells.
Noise, especially noise produced by machines, has always been regarded as a nuisance. It has also been known for some time that persons in certain occupations can suffer noise-induced hearing loss. In addition, there is evidence that the population at large can experience some hearing loss because of the amount of noise the environment from human activity. There is also evidence that excessive noise may have psychologically bad effects.