There has been decades of research conducted by environmental scientists. In a recent article in the Chemical and Engineering News, scientists are now convinced that some chemicals will persist for at least 40 years or more, and some will remain forever.
Prior to 1972 when its use was banned, DDT was a commonly used pesticide. Although it is no longer used or produced in the United States, we continue to find DDT in our environment. Other parts of the world continue to use DDT in agricultural practices and in disease-control programs. Therefore, atmospheric deposition is the current source of new DDT contamination in our Great Lakes. DDT and its break-down products DDE and DDD are persistent, bioacculumative, and toxic (PBT) pollutants targeted by the EPA, said the EPA on its website.
DDT was found in umbilical cord blood in 2011:
Ronald Hites from the University of Indiana and other researchers have tracked the movements through the environment of persistent chemicals, such as DDT, PCBs, and PAHs. Scientists were surprised to find evidence of DDT 40 years after it was banned, contradicting the previous notion that the chemical broke down in the atmosphere in a matter of days, reported the Environmental Monitor.
Scientists have found that DDT and other chemicals are able to:
- Get into the atmosphere
- Be collected in water
- Seep into the soil or sediment
- Be placed into landfill
The problem being that they have found it can then be released back into the atmosphere.
The chemicals have also been found to persist in animal and human blood and tissue for decades.
NASA finds high levels of banned ozone-destroying chemical in Earth’s atmosphere:
Hites’ research was mainly based on data that was obtained in the Great Lakes region through decades of study. There has been a gradual decline in the concentrations of the banned chemicals, but a lot of people wonder if they will ever go away completely.
It seems that nothing has really changed with the chemicals we use; we come up with new chemicals just to find later that there are bad. Perhaps we need to learn to work with nature, rather than against it.