Toxic, Persistent, and Pervasive

What are POPs?

Persistent Organic Pollutants (POPs) are toxic substances composed of organic (carbon-based) chemical compounds and mixtures. They include industrial chemicals like PCBs and pesticides like DDT.

They are primarily products and by-products from industrial processes, chemical manufacturing and resulting wastes. The existence of POPs is relatively recent, dating to the boom in industrial production after World War II.

Why are POPs a threat?
Today, POPs are found almost everywhere - in our food, soil, air and water. Wildlife and humans around the world carry amounts of POPs in their bodies that are at or near levels that can cause injury.

POPs pose a particular hazard because of four characteristics: they are toxic; they are persistent, resisting normal processes that break down contaminants; they accumulate in the body fat of people, marine mammals, and other animals and are passed from mother to fetus; and they can travel great distances on wind and water currents.

Even small quantities of POPs can wreak havoc in human and animal tissue, causing nervous system damage, diseases of the immune system, reproductive and developmental disorders, and cancers.

Of the numerous POPs that are prevalent in our environment, 12 of the most persistent, bioaccumulative chemicals have been identified for priority action. These 12 POPs are targeted in a new international treaty. The Stockholm Convention on Persistent Organic Pollutants will phase out and eliminate the production and use of those chemicals, as well as new ones that would be added once the treaty is in force.

The 12 targeted POPs include eight pesticides (aldrin, chlordane, DDT, dieldrin, endrin, heptachlor, mirex, and toxaphene), two types of industrial chemicals (polychlorinated biphenyls or PCBs and hexachlorobenzene), and two chemical families of unintended by-products of the manufacture, use, and/or combustion of chlorine and chlorine-containing materials (dioxins and furans).

All 12 targeted POPs are also endocrine disruptors?chemicals that can interfere with the body?s own hormones. Endocrine disrupting chemicals can be hazardous at extremely low doses and pose a particular danger to those exposed in the womb. During prenatal life, endocrine disruptors can alter development and undermine the ability to learn, to fight disease, and to reproduce.

Mammals such as harbour porpoises and North Sea seals have impaired immune systems caused by ... 
© WWF / Jan Van De Kam
Mammals such as harbour porpoises and North Sea seals have impaired immune systems caused by industrial chemicals. Some scientists believe this was a factor in the recent large-scale seal deaths in the North Sea.
© WWF / Jan Van De Kam