DDT - A Brief History and Status
Questions on Pesticides?
- National Pesticide Information Center (NPIC)
Development of DDT
This page summarizes EPA's activities regarding the pesticide DDT. Links to related and historical information are below.
DDT (dichloro-diphenyl-trichloroethane) was developed as the first of the modern synthetic insecticides in the 1940s. It was initially used with great effect to combat malaria, typhus, and the other insect-borne human diseases among both military and civilian populations and for insect control in crop and livestock production, institutions, homes, and gardens. DDT's quick success as a pesticide and broad use in the United States and other countries led to the development of resistance by many insect pest species.
Regulation Due to Health and Environmental Effects
The U.S. Department of Agriculture, the federal agency with responsibility of regulating pesticides before the formation of the U.S. Environmental Protection Agency in 1970, began regulatory actions in the late 1950s and 1960s to prohibit many of DDT's uses because of mounting evidence of the pesticide's declining benefits and environmental and toxicological effects. Rachel Carson's book Silent Spring in 1962 stimulated widespread public concern over the dangers of improper pesticide use and the need for better pesticide controls.
In 1972, EPA issued a cancellation order for DDT based on adverse environmental effects of its use, such as those to wildlife, as well as DDT’s potential human health risks. Since then, studies have continued, and a causal relationship between DDT exposure and reproductive effects is suspected. Today, DDT is classified as a probable human carcinogen by U.S. and international authorities. This classification is based on animal studies in which some animals developed liver tumors.
DDT is known to be very persistent in the environment, will accumulate in fatty tissues, and can travel long distances in the upper atmosphere. Since the use of DDT was discontinued in the United States, its concentration in the environment and animals has decreased, but because of its persistence, residues of concern from historical use still remain.
Since 1996, EPA has been participating in international negotiations to control the use of DDT and other persistent organic pollutants used around the world. Under the auspices of the United Nations Environment Programme, countries joined together and negotiated a treaty to enact global bans or restrictions on persistent organic pollutants (POPs), which includes DDT, known as the Stockholm Convention on POPs. The Convention includes a limited exemption for the use of DDT to control mosquitoes which are vectors that carry malaria - a disease that still kills millions of people worldwide.
In September 2006, the World Health Organization (WHO) declared its support for the indoor use of DDT in African countries where malaria remains a major health problem, citing that benefits of the pesticide outweigh the health and environmental risks. This is consistent with the Stockholm Convention on POPs, which bans DDT for all uses except for malaria control.
DDT is one of 12 pesticides recommended by the WHO for indoor residual spray programs. It is up to countries to decide whether or not to use DDT. EPA works with other agencies and countries to advise them on how DDT programs are developed and monitored, with the goal that DDT be used only within the context of Integrated Vector Management programs, and that it be kept out of agricultural sectors.
The following may be helpful sources of additional information on DDT:
- DDT - EPA History
- DDT, A Review of Scientific and Economic Aspects of the Decision to Ban Its Use as a Pesticide (EPA-540/1-75-022)
- Persistent Bioaccumulative and Toxic (PBT) Chemical Program - DDT
- National Pesticide Information Center (NPIC) DDT Fact sheet
- Stockholm Convention on POPs
- The USAID is the federal agency that provides technical assistance to developing countries, including programs for malaria controls.
- The World Health Organization provides information about malaria control, including information about use of DDT in indoor residual spay programs