家中が蚊帳
Posted by Sean at 03:28, September 16th, 2006Well, it’s about time:
The cost of DDT is low, so it had become the insecticide of choice to kill lice and mosquitoes after the 1940s, but after the heightening of interest in environmental problems in the ’60s, it was designated a harmful chemical substance and its use forbidden in country after country.
According to WHO, in cases in which it is restricted to indoor use, it has almost no environmental impact, and it has become clear from recent research that it has no carcinogenic effect on humans. WHO states that it is s it diffuses through indoor spaces, it “makes the inside of the house into one big mosquito net,” preventing the mosquitoes that transmit malaria from landing on walls and ceilings.
This is not new information. (Kindly ignore Ronald Bailey’s misplaced participle in the second sentence.):
DDT has, of course, been a major target for the environmentalist movement ever since Rachel Carson hexed it in her influential 1962 book, Silent Spring. Widely used as an agricultural pesticide, Carson accurately indicted DDT for harming various forms of wildlife. Less accurately, she and others in her wake fingered residual DDT as causing problems in human beings, including increased rates of cancer. In 1972, the U.S. Environmental Protection Agency, then only two years old, banned it, a policy adopted by many other countries. Worldwide use of the pesticide plummeted. DDT remains a powerful symbol of environmental sin and environmentalists have literally been pursuing it to the ends of the Earth in their efforts to banish it forever. Elimination under the POPs Treaty was to be their final triumph over this accursed chemical.
However, it turns out that spraying small quantities of DDT on the interior walls and eaves of living spaces is one of the most effective ways to control malaria-carrying mosquitoes. In fact, during the 1950s and 1960s, DDT use nearly eradicated malaria in many countries. For example, malaria in Sri Lanka dropped from 2.8 million cases in 1948 to 17 in 1963. In India, the case load dropped from 100 million in 1935 to under 300,000 in 1969. Bangladesh was declared a malaria-free zone. DDT was also an important weapon against malaria in parts of the United States and Italy. The World Health Organization estimates that DDT may have saved as many as 50 million lives since it was introduced in 1945. A grateful world cheered when the man who discovered DDT’s properties as an insecticide was awarded the Nobel Prize in 1948.
Let’s hope WHO follows through.