Wednesday, July 24, 2019
Article Critique Assignment Example | Topics and Well Written Essays - 750 words
Article Critique - Assignment Example The use of DDT, however, is heavily regulated under the World Health Organizationââ¬â¢s Position Statement on DDT and the agreement named Stockholm Convention of Persistent Organic Pollutants. These documents allow the use of DDT only for Indoor Residual Spraying and that too until equally effective and affordable alternatives are developed. DDT has 6 to 12 months effectiveness when sprayed on walls and ceilings of homes. This is the longest residual life of any insecticide. Apart from that, DDT casts irritant effect on disease vectors creating strong spatial repellency and reducing human - vector contact significantly. This results in mosquitos feeding off at far off places outside the houses, thereby tremendously hampering the transmission of the disease in human population (WHO). Moreover, the cheapness of the chemical and ease of its use have made it a hit over the years. But, in opposition to all the above mentioned benefits of DDT, there have been bundles and bundles of stud ies carried out by critics, highlighting its human health and environmental harms. A human can get exposure to DDT through a number of ways; from eating foods that were sprayed by it, in-taking contaminated air or water, breast feeding by an exposed mother, or simply by breathing or swallowing soil particles from areas that were DDT sprayed. In response to its exposure, among the many harms that have been discovered, the most frequently reported ones are breast cancer, diabetes, brain damage, genital birth defects and reduced fertility. All these effects can be attributed to the high chemical stability of DDT in the four phases of disposition of its toxicity i.e., absorption, distribution, metabolism and excretion. The chemical has the quality of accumulating in the environment through cells of exposed organisms and organic food chains, which is primarily the reason why its toxicity lingers on and shows after effects in sprayed areas till long after. From the look of things, the dra wbacks of DDT seem to considerably outweigh its benefits, but it is interesting to find out after profound research, that almost all the studies that report potential harms from the use of DDT are either weak or contradictory to each other. This can be proven both through scientific research and the numerical data from plagued areas. A recent paper compiled under co-authorship of a senior officer of Ugandaââ¬â¢s Malaria control program found only average concentrations of plasma DDT/DDE (77ppb) in the spray team after a continuous six months of IRS with the chemical (Bismenya et al.). Similarly, new information on increased levels of accumulation in human milk and exposures to DDT was evaluated in 2010 by WHO expert consultation. The reported levels were concluded to be below level of concern of human health (WHO). A lot of the times, studies have been conducted on laboratory animals and the effects found on them have been generalized on human beings without proper confirmation. WHO then analyzed epidemiological data and found no support for these findings in humans in 2007. Adding further to the support of use of DDT are the actual cases and data from the strongly affected countries. In Sri Lanka, use of DDT had reduced malaria cases from 2.8 million in 1948 to 17 in 1963. After spraying was banned in the next decade, malaria
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