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'Persistent organic pollutants' ('POP's) are organic compounds that are resistant to environmental degradation through chemical, biological, and photolytic processes. Because of this, they have been observed to persist in the environment, to be capable of long-range transport, bioaccumulate in human and animal tissue, biomagnify in food chains, and to have potential significant impacts on human health and the environment.
In May 1995, the UNEP Governing Council (GC) decided to begin investigating POPs, initially beginning with a short list of the following twelve POPs: aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, hexachlorobenzene, mirex, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, and toxaphene.
Since then, this list has generally been accepted to include such substances as carcinogenic PAHs and certain brominated flame-retardants, as well as some organometallic compounds such as tributyltin (TBT).
The groups of compounds that make up POPs are also classed as PBTs ('P'ersistent, 'B'ioaccumulative and 'T'oxic) or even TOMPs ('T'oxic 'O'rganic 'M'icro 'P'ollutants.)

Contents

Chemical properties

Long-range transport

Health concerns

Trends

See also

External links

References

Chemical properties

Some of their chemical characteristics include low water solubility, high lipid solubility, high molecular masses and low volatility. One important factor of their chemical properties results in the ability to accumulate in the fatty tissues of living organisms.

Long-range transport

POPs released to the environment have been shown to travel vast distances from their original source. Due to their chemical properties, many POPs are both involatile and insoluble. These compounds are therefore unable to transport directly through the environment. The indirect routes include attachment to particulate matter, and through the food chain.

Health concerns

A study by Duk-Hee Lee et al. published in 2006 indicated a link between blood serum levels of POPs and diabetes.^[1] Individuals with elevated levels of persistent organic pollutants (DDT, dioxins, PCBs and Chlordane, among others) in their body are 38 times more likely to be insulin resistant than individuals with low levels of these pollutants. The study however did not demonstrate a cause and effect relationship. As most exposure to POPs is through consumption of animal fats, study participants with high levels of serum POPs are also very likely to be consumers of high amounts of animal fats, and thus the consumption of the fats themselves, or other associated factors may be responsible for the observed increase in insulin resistance. Another possibility is that insulin resistance causes increased accumulation of POPs. Among study participants, obesity was associated with diabetes only in people who tested high for these pollutants. These pollutants are accumulated in animal fats, so minimizing consumption of animal fats may reduce the risk of diabetes.^[2]

Trends

The general trend of POPs is the following:

★ Synthesis/development.

★ Increased use over large areas in Europe and North America.

★ Concerns over their persistence, bioaccumulation, and bioconcentration.

★ Restricted use.

★ Reduced emissions, as well as bans and controls.

See also

★ Center for International Environmental Law (CIEL)

★ Food chain

★ International POPs Elimination Network (IPEN)

★ Stockholm Convention

External links

★ Environmental Working Group - POPs/PBT investigation

★ Greenpeace: Chemicals out of control

★ Pesticide Action Network North America

★ The PAN Pesticides Database

★ Pesticide Action Network (PAN) is a network of over 600 NGOs worldwide

★ Pesticide Action Network UK (PAN UK) promotes healthy food, agriculture and an environment without dependence on toxic chemicals, and without harm to food producers and agricultural workers

★ Stockholm Convention on Persistent Organic Pollutants

★ WWF: Detox Campaign

★ POP monitoring in the Alpine region (Europe)

References

1. D-H Lee et al A Strong Dose-Response Relation Between Serum Concentrations of Persistent Organic Pollutants and Diabetes Diabetes Care 29:1638-1644, 2006
2. Living on Earth: POPsible Nightmare


★ Environmental Chemistry Group Newsletter, issue no. 14, July 2001