What is DDT?
DDT, or Dichlorodiphenyltrichloroethane is a class of POPs, toxic, man-made, hazardous chemical, first synthesized in 1874, its insecticidal properties were discovered in 1939.
DDT hazardous effects
DDT bioaccumulate in fatty tissues of humans and animals. DDT is classified as ‘probably carcinogenic’ to humans class 2A according to IARC-WHO with strong evidences that DDT can supress the immune system and disrupt sex hormones: high intake of DDT is associated with developmental and reproductive abnormalities. Because of its stability, persistence, and widespread use, DDT residues are found everywhere, even in very remote places such as the Artic, the Antarctic, open oceans, and high mountain areas. Birds are amongst the most affected animals because DDT causes eggshell thinning. DDT is also acutely toxic to fish and marine invertebrates.
In 1962, a marine biologist, Rachel Carson, published what became a best-seller "The Silent Spring". The book showed the devastating effects of people on nature by documenting the effect of pesticides on the natural world, focusing on DDT. Deployed as an insect killer in the U.S. after the second world war, DDT was poisoning the natural food chains in American waters. DDT sprayed on vegetation washed into the oceans. Concentrations rose in fish, which were then eaten by birds of prey, especially ospreys. DDT caused the birds to lay eggs with abnormally thin eggshells, so thin the eggs cracked in the nest when the parent birds tried to incubate them. And so the birds began to die off.
DDT is the most abundant and shows the highest values of all POPs measured in all matrices around the world.
DDT uses and production
DDT has been one of the most widely used pesticides in the world, its use peaked between 1946 and 1972, DDT was applied as an insecticide in agriculture. Despite continued efforts to introduce effective alternatives, several countries still rely on DDT as an option against malaria and, in the recent past, against visceral leishmanisasis, both illnesses spreading through mosquitoes’ bites.
Since 2008, Hindustan Insecticide Ltd factories, in India, is the only registered site for DDT production in the world. India exports DDT to countries in Asia-Pacific and African regions. Use of DDT is also largely concentrated in India. HIL (India), a public sector enterprise, is the only manufacturer of DDT in the world and is now committed to phase out production of DDT by 2024 (source: Good Practice Brief: Promoting Non-POPs Alternatives to DDT and Environmental Health Through Engaging Key Local Partners, theGEF, Sep 2022).
DDT Stockpiles
Around the world, sound disposal of obsolete DDT stockpiles is needed, particularly where stockpiles pose immediate risks to human health and the environment. It is clear from available information that large amounts of DDT have been produced in the past, and as of today, still substantial amounts are stored in many countries, often buried in landfills. Most of these stocks are not fit for use anymore, the long-term storage in unmanaged landfills leads over time to an additional, continuously growing volume of contaminated soil in need of treatment and disposal. The report Global Inventory of DDT Stockpiles and DDT in Landfills (UNEP 2019) tries to give a better understanding of the amount and distribution of obsolete stockpiles of DDT and waste containing DDT, in order to speed up the process of their disposal – nationally, regionally and globally.
The interactive dashboard below presents global information about DDT production, use, stockpiles and concentration levels measured in air and human milk.
(The data presented in the dashboard have been compiled in one Excel file that can be downloaded. If you experience difficulties in the download, please try with a different browser such as Firefox or Edge)
Open the DDT dashboard in a new tab
GMP Dashboard
The interactive GMP Dashboard presents results on POPs monitoring worldwide. DDT scores the highest concentrations level measured of all POPs, in air, human milk and samples of national interest, however, remarkable decline of DDT concentration was observed in countries which regulated DDT.
A global treaty to protect human health and the environment from POPs
In 2004, the Stockholm Convention listed DDT in Annex B, restricting the production and/or use of DDT for disease vector control when no locally safe, effective and affordable alternatives are available, in accordance with WHO recommendations and guidelines.
Parties of the Stockholm Convention are required to notify the Secretariat their production or use of DDT, or their intention to produce or use in the future, these are reported in the Register for acceptable purposes.
The DDT Expert Group undertakes an assessment of scientific, technical, environmental, and economic information related to DDT and reports its recommendations to the Conference of the Parties of the Stockholm Convention for its consideration in the evaluation of continued need of DDT for disease vector control (see UNEP/POPS/COP.10/INF/9) in consultation with the WHO (see UNEP/POPS/COP.10/INF/10).
In July 2021, the 10th Conference of the Parties of the Stockholm Convention initiated a consultative process on a possible DDT phase-out plan.
A transition away from DDT toward locally safe, effective, affordable, and environmentally sound, alternatives is key for a sustainable future
The Road Map for the Development of Alternatives to DDT was presented to the COP at its seventh meeting in 2015. The Road Map is an overarching and holistic framework for action, aiming to empower countries. It provides a thematic guide and sketch the steps that are needed to make locally safe, effective, affordable, and environmentally sound alternatives available for a sustainable transition away from DDT, including environmentally sound management and disposal of DDT stockpiles (unused or obsolete).
As a follow up, UNEP is now implementing the project “Assistance for the establishment of national road maps for the development of alternatives to DDT” within Namibia and Uganda.
Through GEF funding, India has taken the first step to eliminate dependency on the insecticide DDT by promoting locally appropriate, cost-effective, and sustainable alternatives, including the Long-Lasting Insecticidal Net (LLIN) and Neem-based and bacteria-based biopesticides.
