Persistent organic pollutant

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Persistent organic pollutants (POPs) 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 compouds that make up POPs are also classed as PBTs (Persistent, Bioaccumulative and Toxic) or even TOMPs (Toxic Organic Micro Pollutants.)

Contents 1 Chemical Properties 2 Long Range Transport 3 Trends 4 See also 5 External links 6 References

[edit] 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.

[edit] 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.

[edit] 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.

[edit] See also

• Center for International Environmental Law (CIEL)
• Food chain
• International POPs Elimination Network (IPEN)
• Stockholm Convention

[edit] 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)

[edit] References

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