Effects of DDT

DDT Spray

Dichloro-diphenyl-trichloroethane, better known as DDT, was developed in the 1940s primarily to combat insect-borne diseases that were becoming rampant throughout many countries. Malaria, yellow fever, dengue fever, Japanese encephalitis and the West Nile virus are just a few example of the types of diseases that can be spread by these infectious insects, mainly the mosquito. Because of DDT’s chemical composition it became a successful weapon in combating these prevalent diseases by practically eradicating most species of the mosquito. However DDT’s purpose began to shift towards that of an agricultural insecticide with over usage deteriorating farmland ecosystems. Subsequently, it was banned from the United States and eventually worldwide. Now the question to consider is whether DDT should again be implemented to combat the diseases in which current efforts have proved insufficient before they reach epidemic proportions.

  

Mosquito: Primary Carrier of Malaria

Malaria is probably the most thought of vector-borne communicable disease as it infects upwards of 247 million people worldwide every year. The fact that there exists a chemical which could potentially eliminate this deadly disease worldwide is revolutionary; however there are substantial consequences to take into consideration when subjecting ecosystems to the chemical. Studies have shown that the pollution of DDT negatively affects a variety of freshwater and marine species, including algae. Although the microorganisms comprising of the algae usually remain resistant to the DDT, they do absorb the chemical and the harmful effects are passed down to those animals that come in contact with it. Reproductive rates of certain fish-eating birds have also been observed, as well as the thinning of their eggshells.

Thinning of Eggshells

The lasting effects DDT has had on humans haven’t been as negligible as one might think. Originally, DDT was thought to be harmless to humans considering it cannot be absorbed through the skin, but recent studies were conducted given the apparent affects it was having on wildlife confirming that the chemical indeed is a determent to human health as well. Scientists have recently reported that DDT may have numerous health effects such as genital birth defects, breast cancer, reduced fertility, diabetes and damage to developing brains. A study done in South Africa showed that men living in homes where DDT was sprayed had extremely high levels of DDT in their blood and had a lower sperm count. In a study posted in the Environmental Health Perspectives journal, research showed that exposure to DDT is also associated with hypertension.

DDT

Completely eradicating a species from an ecosystem can also have impacting residual effects, with either predators lacking prey or plants lacking pollinators. Arguments have been placed that the ecological scar left by missing mosquitoes would heal quickly as the niche would be filled by other organisms. Most mosquito-eating birds would probably adjust their diet to the other insects that would rapidly emerge in large numbers post-mosquito. It is estimated that sub-Saharan Africa, might recover the 1.3% of growth in GDP that they are cost by the disease each year by implementing vast DDT use. This economic growth does come with a cost though, and it’s paid for by ecosystems and even by humans. Individuals just need to decide if this cost is worth investing in, and quickly. 

Lindsey Ayers, David Timothy, Sugey Lopez