WHAT IS DDT?

The letters "DDT" stand for dichloro-diphenyl-trichloro-ethane. DDT is an insecticide used to control insect-borne diseases. While it is no longer registered for use in the United States, DDT is still used in other countries. Most of these countries are located in tropical regions and use DDT as a preventative for malaria, a deadly mosquito-borne disease.

A BIT OF DDT HISTORY:

During the World War II era, DDT was hailed as the "savior of mankind". The chemical had proved itself to be an efficient means of preventing the transmittal of such diseases as typhus, associated with the flea, and malaria, associated with the mosquito. In its heyday, DDT was the most widely used insecticide of its time. Its popularity was a result of its cheapness, availability, potency, and so-called safety. Because DDT remains in its toxic state for years, farmers enjoyed many seasons of protection from a single spraying.

Immediately following WWII, production of DDT dramatically increased. Between 1945 and 1955 alone, DDT production increased from 125 million pounds to 600 million pounds. DDT was used both publicly and privately and was endorsed by the U.S. government, the chemical industry, and the Public Health Department.

THE DOUBTING OF DDT:

Upon discovering the houseflyís immunity to DDT, several scientists began to become skeptical of the actual safety of DDT. In 1946, two scientists, Elmer Higgins and Clarence Cottam, published an article about the hazardous affects of DDT on various animal species. The scientists concluded that DDT had a tendency to accumulate in the fatty tissue of certain animals.

As a result of the growing concern within the scientific community, congress began an annual census of dead fish, which were apparent victims of pollution. Reports such as these, however, were not made readily available to the public. Consequently, the widespread use of DDT continued.

THE DOWNFALL OF DDT:

The end of DDTís reign in the U.S. was due mostly to Rachel Carsonís 1962 book, Silent Spring. In this book the author described the effects of DDT upon wildlife. She determined that DDT significantly reduced the population of birds of prey, such as eagles. Studies had revealed that eagles and other birds exposed to DDT had serious reproduction problems. Birds that had ingested DDT were found to lay eggs that were susceptible to "shell thinning." These eggs rarely survived long enough to hatch. As a result, the eagle population plummeted.

As a result of Rachel Carsonís findings, along with growing support from the scientific community, DDT was officially banned in the U.S. in 1972. Use of DDT is no longer allowed in the U.S., unless an unusual public health emergency were to arise, such as a widespread outbreak of malaria.

SINCE DDT BAN:

Quantities of DDT residue found in eagles have decreased slowly since 1972. Despite this, however, eagles continue to struggle to recover from the devastating effects of DDT.