Ocean Sentry
A computer simulation by scientists has revealed that substantial quantities of the pesticide DDT are still being released from the world’s oceans, despite widespread restrictions on its use during the 1970s. According to a report in Nature News, the scientists created a computer model to simulate the circulation of DDT between ocean and atmosphere between 1950 and 2002.
This revealed that since the 1970s, the re-emission of DDT from the ocean has become greater than from the three known modern releases of new DDT: its continued use in some countries for malaria control; degrading storage canisters; and other pesticides that contain DDT as a contaminant. The calculations show that although remaining DDT use today tends to be in the southern hemisphere, its concentrations are actually growing in the northern hemisphere as it moves through the world’s oceans and atmosphere. An estimated 1.5 million tonnes of DDT were used worldwide between the 1940s and 1970s, both as an agricultural insecticide and to control disease-carrying insects such as mosquitoes – the chemical was a key weapon in the war against malaria, for example. But, DDT is toxic to a wide range of aquatic life, and its eggshell-thinning effects also had a drastic impact on many bird species…. Read Full Article
