DDT is a chemical which was first found in the year 1874 and was well studied since then. World Health Organization approves of DDT because it has proven to be the most effective when it comes to combating malaria. In conjunction with other preventive measures, it is able to decrease the transmission of malaria when sprayed in homes.
When it was first introduced, it was perceived to be the most effective in reducing malaria. The WHO anti-malaria campaign was successful especially in parts such as Sri Lanka. Today, WHO recommends DDT as one of its top malaria insecticides. In support of the World Health Organization position statement on the use of DDT certain toxicology data has to be assessed first (Raloff, 2001).
For a proposed substance to be used, the nature of the material and the cumulative estimated dietary intake (CEDI) must be considered. If a substance has a CEDI of less than 0.5 ppb, then no toxicology data is needed.
However, all relevant data must be submitted if available. If the exposure is between 0.5 and 50 ppb, a bacterial mutagenicity assay and an in vitro cytogenetic damage or mouse lymphoma assay should be carried out.
The rationale for conducting these two studies is to provide an indication as to whether a given substance is likely to be a carcinogen. Should the intake of the substance exceed 50 ppb but be less than 1 ppm, then a third toxicity test may be required. However, if the substance exceeds 1ppm, then a full range of toxicity studies will be required (Keller and Heckman, 2001).
The four phases of disposition of toxic compounds within the body are based on excretion through the lungs, biliary, urinary and other excretion routes such as breast feeding. DDT has the ability to accumulate in fatty tissues and breast milk. A mother exposed to DDT is likely to give the infant a greater dose of the substance.
The human body is unable to breakdown DDT therefore; this makes it a highly toxic substance to the human body. Foreign compounds are usually secreted into fluids such as sweat, semen, tears and other compounds may be secreted into the saliva or stomach. The body is unable to dispose of DDT. The human body has the ability to store DDT in tissues and bodily fluids but is unable to break it down and dispose of it.
To begin with, DDT has raised some concerns about its toxic nature just like other pesticides have. It is believed to cause neurologic impairment, headaches, vomiting, tremors and other known effects. In addition, it is known to cause environmental problems. Its chemical sustainability enables it to accumulate in the environment through food chains, and in tissues of exposed organisms, including the people that live in treated houses.
Research has shown that exposure to DDT might cause preterm birth and early weaning. It may also interrupt the semen quality, menstruation and gestational length. Other studies have shown that daughters of mothers who have been pre-exposed to DDT may have difficulty becoming pregnant and may also suffer from miscarriage.
Due to its carcinogenicity, DDT is believed to cause cancer. Studies on the human populations have shown that DDT can cause cancer of such organs as liver and pancreas, and be a reason of the breast cancer. However, other studies have shown that it doesnât cause prostate cancer (Moeller, 2005).
The use of DDT has remained in use in some areas and this has brought about some controversial issues. Part of the controversy is that malaria has become widespread in areas where the use of DDT has been banned. However, the DDT is still used in some countries, one of which is South Africa. However it uses it under WHOâs guidelines.
Initially, the country had switched to using other alternative insecticides. After a while it became clear that the malaria incidences had increased dramatically. Other areas where malaria increased dramatically after they stopped using DDT include South America and Ethiopia.
Resistance has however reduced DDTâs effectiveness in eradicating malaria. Resistance is largely due to prolonged agricultural use and as a result, WHO recommends that absence of resistance must be confirmed before proceeding to use the substance. Resistance was noted in spray campaigns where it was noted that it had lost its effectiveness in areas such as Sri Lanka, Pakistan, and Central America.
There have been concerns over the usage of DDT in small scale spraying and spraying of entire agricultural areas. Since the ban of DDT, more information on its effects has risen. Such information includes its effects on environmental and human health.
It is believed that its effects on the bird populations and its hormonal effects on fish and amphibians may have been underestimated. Recent studies have shown that it exposes younger generations at a great risk of getting cancer due to its carcinogenic effect(Cohn, Wolff, Cirillo, and Sholtz, 2007).
DDT has been criticized over its current use. Critics claim that restricting the use of DDT in areas when malaria is widely spread has caused many unnecessary deaths over the years. In 2007 it was estimated that the ban on DDT caused over 20million deaths and that population was children only.
Critics often reference the 1972 US ban on DDT claiming that it cost millions of lives. It is also believed that donor governments and agents have refused to fund DDT spraying in some regions. For instance, the use of DDT in Mozambique was stopped years ago.
The reason being that it was believed that 80% of the countryâs health budget was due to donor funds while donors were against the usage of DDT. Many countries that face this problem have been forced to bow down under pressure to give up DDT or face losing aid grants.
The United States Agency for International Development has been under much criticism of late. These days, the agency is now providing funds to the usage of DDT in African countries though it did not do this in the past years. The agency was accused of “not funding the use of DDT because it was not âpolitically correctâ” (Raloff 2001).
It currently however strongly supports the use of DDT in malaria stricken areas and is willing to continue supporting it once it is scientifically proven to be sound and warranted.
Alternative uses of DDT are believed to be more expensive, more toxic and less effective. The vulnerability of mosquitoes varies from region to region. Similarly, alternative insecticideâs similarities also vary. Therefore, the toxicity and cost effectiveness comparison of DDT and alternative insecticides lacks significant data.
Despite its detrimental effects, DDT has been proved to be the most effective chemical agent that decreases transmission of malaria. The question of whether to use it or not has however been a question of risk versus benefit. The malaria epidemic in certain parts of the world, such as Africa, has justified the use of DDT.
In order to continue using it, vigilance must be maintained at all times but this doesnât mean that research should not be continued in order to find more sustainable and suitable methods of fighting the disease.
It is well-known that continued use or overuse of any substance eventually causes an organism to adapt and become resistant to it. DDT should therefore be used as a bridge to keep the malaria epidemic at bay as more appropriate measures and solutions are sought after. This may include improvement in treatment and the discovery of a vaccine.
Works Cited
Cohn, Bernard, Wolff McCintire, Philip Cirillo and Richardson Sholtz. “DDT and breast cancer in young women: New data on the significance of age at exposure”. Environmental Health Perspectives 115.10 (2007): 1406â1414. Web.
Keller and Heckman. “Toxicology Requirements: What Types of Toxicity Data Must Be Submitted?” packaginglaw.com. 2001.Web. <www.packaginglaw.com/2771_.shtml>
Moeller, Dennis. W. Environmental Health. Cambridge: Harvard University Press, 2005. Print.
Raloff, Jeffery. “The Case for DDT”. Science News, 158.1 (2001): 12. Academic Search Premier database. Web.