Why is ddt nolonger used for indoors spraying in preventing malaria?
It is used. See link. Note, it is also used much more carefully than it was by farmers in the 1960’s. Tiny amounts are used to treat homes, compared to what was used in fields. This paragraph is from the section “Restrictions on usage.” “Today, about 4-5,000 tonnes of DDT are used each year for vector control.[13] In this context, DDT is applied to the inside walls of homes to kill or repel mosquitos entering the home. This intervention, called indoor residual spraying (IRS), greatly reduces environmental damage compared to the earlier widespread use of DDT in agriculture. It also reduces the risk of resistance to DDT.[29] This use only requires a small fraction of that previously used in agriculture; for example, the amount of DDT that might have been used on 40 hectares (100 acres) of cotton during a typical growing season in the U.S. is estimated to be enough to treat roughly 1,700 homes.” Note, there is a reference to ddt in the famous song “Big Yellow Taxi,” written and originally
Well in 1962, Rachel Carson wrote a book called Silent Spring. In it, she argued that pesticides, and especially DDT, were poisoning both wildlife and the environment and also endangering human health. DDT became the prime target of the growing anti-chemical and anti-pesticide movements during the 1960s because (1) DDT was a carcinogen, and (2) it endangered the environment, particularly for certain birds. A number of states moved to ban DDT, and in 1970 the U.S. Department of Agriculture announced a plan to phase out all but essential uses. However, there was fierce opposition to this move in the 60’s & 70’s. Some scientists found evidence that the studies meant to discourage DDT use had been tampered with and thus declared them erroneous. In 1970 the National Academy of Sciences declared, “In little more than two decades, DDT has prevented 500 million human deaths due to malaria, that would otherwise have been inevitable.” The ban on DDT was considered the first major victory for the
