Persistent organic pollutants, abbreviated to POPs, are carbon-based compounds named for their persistence, in that they are resistant to degradation. POPs do not readily dissolve in water but are easily trapped in the soil and are also soluble in lipids. POPs do not decompose with ease because of their stability and its low rate of decay. Therefore the POPs remain in the environment long after measures are put in place to control their spread and accumulate in the environment and in the human body posing a significant risk. Most POPs are artificial, obtained from substances used in pest control, solvents, medicines and manufacturing chemicals. There are also POPs created by natural causes such as those from volcanoes.
Effects of Persistent Organic Pollutants
POP environmental contamination is widespread. This contamination happens when the POPs gets into the air when they evaporate from the soil and water into the atmosphere. In the air, the POPs can travel far distances from areas of emission before being deposited in new areas.
POP containing substances are taken in much faster than the rate at which it is lost through metabolism which results in accumulation. With time it impacts adversely on the organism. The easy solubility of POPs in lipids enables them to collect in the fatty tissues of the animals for an extended period. The more the POPs accumulate, the higher the toxicity in the animals and the environment. The exposure to POPs may cause growth problems, long-term diseases, and death. Some POPs are carcinogenic. Others can cause reproductive problems, disrupt the central nervous system and the immune system.
The effects of POPs in organisms and human bodies are hard to determine in a laboratory setting. The impacts of POPs are assumed to be equal when two chemicals are together and when the sum of two substances taken individually. This interaction occurs in a case where the organism was exposed to a mixture of POPs, although the POPs produce a synergistic effect whereby the degree of impact is higher when two chemicals are taken together than when the sum of each is made in equal quantities. The harmfulness of every compound is heightened or lowered by the existence of other compounds in the mixture with the synergistic effects.
Stockholm Convention was embraced and implemented by the United Nations Environment Program (UNEP) in 2001 to guard human being and the environment from persistent organic pollutants. As of 2014, 179 countries have complied with the agreement after realizing the harmfulness and the adverse effects the POPs. The Stockholm Convention tries to find out and then evaluate whether the chemicals developed with the progress in technology are POPs. In the first meeting held in 2001 members of the convention made a list of chemicals categorized as POPs termed as the "dirty dozen."