DDT, the Environment, and the Law of Unintended Consequences

Spraying DDT against the body louse, WWII.

Rachel Carson warned the world in the early 1960s, through her now classic book "Silent Spring", about the dangers of single use pesticides, specifically Dichlorodiphenyltrichloroethane (DDT).

This product won the 1948 Noble Prize for its developer, Paul Hermann Müller, given its successful use against arthropods, including by U.S. Allies in WWII to reduce exposure of military troops to debilitating louse-borne typhus and mosquito-borne illnesses, like malaria and dengue fever.

DDT also became popular in the 1950s and 60s as an agricultural pesticide, with tens of thousands of tons of product sprayed on crops for human consumption.  This was because DDT is a lipophilic persistent organic pesticide, which means it bio-accumulates in fatty tissue of animals and moves up the food chain, is found in human breast milk, and also bio-concentrates in the soil, being present for 15+ years.  Carson also warned that DDT was decimating bird populations due to its effect of weakening the egg shell.  In essence see foresaw a "silent spring" coming if DDT continued to be used as an agricultural pesticide.

She also warned, prophetically, that reliance on a single strong pesticide would disrupt ecological systems and have unintended consequences.  Many countries, including the U.S. in 1972, banned the agricultural use of DDT, at the same time the World Health Organization was having initial success in eradicating malaria with the use of DDT.  To date, DDT has been banned in 34 countries and severely restricted in 34 others.

See this NY Times Video clip for an in-depth discussion of this issue.

Take care,

Jim