We all share the same concern about the use of pesticides and the potential health risks they pose to us and our environment. Revisiting the damage done by the pesticide dichlorodiphenyltrichloroethane (DDT) on the eastern coast of South Africa, we see the initial effects, long-term effects, and the risk posed to us even today. Currently, people are using pesticides more than ever before, leading to higher levels of human consumption than ever seen. This high consumption of pesticides is very problematic because they can cause reproductive problems, neurological problems, cognitive problems, and developmental problems.
The type of pesticide determines its health effects. Organophosphates and carbamates, for example, affect the nervous system. Others irritate the skin or eyes. Some pesticides cause cancer, while others disrupt the hormone or endocrine system. The EPA assesses health risks by determining that pesticide residues on food pose “reasonable certainty of no harm.”
The Effects of DDT on South Africans 2000-2007
Countries that signed the 2001 Stockholm Convention banned chemicals such as DDT and lindane, initially including South Africa. However, South Africa reintroduced the chemical under the new name DDT IRS in 2000 to aid residents during a malaria epidemic associated with the emergence of a pyrethroid-resistant strain of Anopheles funestus. South Africa accumulated an estimated 386 tons of DDT, meaning it had to spray an average of 280,000 homes, directly affecting the lives of at least 1.125 million South Africans.
Pesticides, by their nature, potentially harm other organisms, including humans, so we need to use them safely and dispose of them properly. They rank among the leading causes of death by self-poisoning, disproportionately affecting low- and middle-income countries. DDT and other chlorinated insecticides stimulate and depress the central nervous system. Single doses of 6 to 10 milligrams in humans cause neuro-developmental effects such as nausea, headaches, diarrhoea, irritation of the mucous membranes, tremors, convulsions, and nervous system abnormalities. DDT may also damage the liver and central nervous system, causing excitability and seizures in people.
The Lasting Effects of Pesticides
Older, cheaper (off-patent) pesticides like DDT and lindane can remain in soil and water for years. Even if an area used these pesticides years ago, traces of these chemicals might still be in your drinking water. Borehole water also carries pollutants, such as various pesticides and heavy metals, that get absorbed into the soil. Rain washes pesticides from crops into flowing water downstream, causing farms to unintentionally contaminate bodies of water. Drinking untreated water is hazardous, especially over the long run, as you unknowingly ingest these pesticides in your water for several years.
The Environmental Impact of Pesticides
Pesticide use contributes to environmental harm in surrounding areas as the seasons progress. Pesticides significantly harm wildlife across the planet, causing effects such as stunted growth, damaged reproduction, and behavioural changes in non-target animals. More than 800 species, both inland and aquatic, suffer detrimental effects, including reduced growth rates, reproductive success, and abilities to catch prey or attract mates. Therefore, the true extent of pesticide harm may be even greater than reported.
How do you protect yourself from Pesticides?
To minimize your exposure to pesticides in your food, shop organically and wash and peel your produce before ingesting it. Organic farmers do not use harmful pesticides on their produce. Animal products contain traces of pesticides due to the kinds of animal feed used. Avoid consuming animal fat because most pesticides are found in the fatty parts of animal products. Air fryers are the perfect solution because while cooking animal products the fats and oils from your food fall off the meat during the cooking process making it overall healthier for you. Minimising your consumption of fats and oils also in turn minimises your potential exposure to pesticides.
Use a water purifier with a reverse osmosis filtration system that includes an activated carbon filter. This filter effectively removes certain pesticides from water. The semi-permeable membrane removes some dissolved pesticides, such as endrin, while activated carbon filtration media absorb other pesticides and their volatile organic compounds. The DNA Water Purifier features a 4-stage reverse osmosis filtration system with a TDS indicator for source and purified water, and a robust four-in-one filter cartridge: a PP cotton filter cartridge, a pre-processing activated carbon filter cartridge, a DNA reverse osmosis filter cartridge, and a post-processing activated carbon filter cartridge. With the DNA Water Purifier and all of its features and functions, you can rest assured that you are protected from pesticides.
References
World Health Organization (1979), Environmental health criteria for DDT and its derivatives.
World Federation of Public Health Associations (2000), Global Programme of Action, Clearing house
mechanism: DDT, UNEP.Wan, NF., Fu, L., Dainese, M. et al. Pesticides have negative effects on non-target organisms. Nat Commun 16, 1360 (2025). https://doi.org/10.1038/s41467-025-56732-x
Nian-Feng Wan et al, Pesticides have negative effects on non-target organisms, Nature Communications (2025). DOI: 10.1038/s41467-025-56732-x
Dalvie MA, Africa A, London L. Disposal of unwanted pesticides in Stellenbosch, South Africa. Sci Total Environ. 2005 Dec 7
Dr Leslie London, Email: “FW, DDT in South Africa”, 23/03/2006
South African Department of Health, Guidelines for Vector Surveillance and Vector Control, 1996. Maharaj. R, Mthembu. J, Sharp. B, (2005), Impact of DDT re-introduction on malaria transmission in KwaZulu-Natal, SA Medical Journal.