The Reintroduction of DDT: Playing Devil’s Advocate for Health Risks to Society Alex Mass

DDT Video: Your Impressions DDT Video: Your Impressions

Mechanism of Action Insecticidal properties discovered in 1939 Insecticidal properties discovered in 1939 Neurotoxin, affecting sodium ion channels Neurotoxin, affecting sodium ion channels –Neurotoxic properties are not bioaccumulative

History of DDT Insecticidal properties discovered in 1939 Insecticidal properties discovered in 1939 –used to eradicate Malaria from Bayou South in US, where up to 7 million people were affected annually –World War II- the first war in global history in which more soldiers died from violence than disease (malaria, typhus, plague, dengue fever) –WW1 affected by Spanish Flu (40 million deaths in 1 year)  Sri Lanka- 3 million cases of malaria in 1958, 18 cases in 1963 (DDT introduced in 5-year program)

DDT as an Unwilling Keystone/Mascot Silent Spring, 1963 Silent Spring, 1963 The introduction of the Green Movement The introduction of the Green Movement The scarlet ‘C’… cancer The scarlet ‘C’… cancer Symbol of industry Symbol of industry The danger of uninformed passion… The danger of uninformed passion…  DDT was replaced with parathion (class A cancer- causing organophosphate insecticide with additive effects)

DDT United Nations Pressure- deny certain types of food aid to nations using DDT United Nations Pressure- deny certain types of food aid to nations using DDT –The ‘unsafe border effect’ Resurgence of malaria, particularly in Africa Resurgence of malaria, particularly in Africa Problems with ‘First World Parenting’ Problems with ‘First World Parenting’ Estimated 57 million ‘preventable’ deaths Estimated 57 million ‘preventable’ deaths

Case study, KwaZulu-Natal province – –DDT use in 50% of structures was able to reduce malarial infection 91% within the first two years. Malarial deaths decreased from 42,000 in 2000 to 2100 in – –After DDT was sprayed in structures, no malarial insects were ever identified in the province in the next six years (through to publication). Comparatively, 3500 malarial insects were identified in 2000 prior to DDT use. WHO's policy has shifted from recommending IRS only in areas of seasonal or episodic transmission of malaria, to also advocating it in areas of continuous, intense transmission WHO's policy has shifted from recommending IRS only in areas of seasonal or episodic transmission of malaria, to also advocating it in areas of continuous, intense transmission –Aims for 30% cut in the application of DDT world-wide by 2014 and total phase-out by the early 2020s

Thresholds of toxicity Noncancer vs Cancer What is ‘safe’? We now know DDT has antiandrogenic effects. It may/ may not cause cancer. Its current insecticidal substitutes DO cause cancer and are far less effective at vector control. We also know better than to spray it in the faces of children; we have a sense of limits we didn’t have in the 1940s. Dose Adverse Effect/ Damage

What is ‘safe’? Where do you draw the line when there is no perfect solution? DDT and Its Derivatives. Geneva: World Health Organisation p. 83. ISBN DDT and Its Derivatives. Geneva: World Health Organisation p. 83. ISBN ISBN ISBN Toxicological Profile: for DDT, DDE, and DDE. Agency for Toxic Substances and Disease Registry, September Toxicological Profile: for DDT, DDE, and DDE. Agency for Toxic Substances and Disease Registry, September Toxicological Profile: for DDT, DDE, and DDE.Agency for Toxic Substances and Disease Registry Toxicological Profile: for DDT, DDE, and DDE.Agency for Toxic Substances and Disease Registry DDT Regulatory History: A Brief Survey (to 1975), U.S. EPA, July DDT Regulatory History: A Brief Survey (to 1975), U.S. EPA, July DDT Regulatory History: A Brief Survey (to 1975) DDT Regulatory History: A Brief Survey (to 1975) Report of the Third Expert Group Meeting on DDT, UNEP/POPS/DDT-EG.3/3, Stockholm Convention on Persistent Organic Pollutants, November 12, Report of the Third Expert Group Meeting on DDT, UNEP/POPS/DDT-EG.3/3, Stockholm Convention on Persistent Organic Pollutants, November 12, Maharaj, Mthembu, and Sharp (2005). Impact of DDT re-introduction on malaria transmission inKwaZulu-Natal. South African Medical Journal Vol 95(11). Stout, Bradham, Egeghy, Jones, Croghan, Ashley, Pinzer, Friedman, Brinkman, Nishioka, and Cox (2009). American Healthy Homes Survey: A National Study of Residual Pesticides Measured from Floor Wipes. Environ. Sci. Technol., 43,