Persistent organic pollutants (POPs) refer to pesticides, industrial chemicals, or unnecessary by-products in industrial processes. They have been used for decades, but recently they have been found to have some disturbing characteristics, including:
l Persistent-they will not degrade in air, water and sediments;
l bioaccumulation-their concentration in biological tissues is higher than that in the surrounding environment;
l Long-range migration-they can spread to a long distance from the release source through air, water and migrating animals, and often pollute areas thousands of kilometers away from any known source.
At present, the Stockholm Convention focuses on 23 kinds of persistent organic pollutants, including pesticides, industrial chemicals and unintentional by-products.
The original 12 kinds of persistent organic pollutants are usually called "dirty dozen", namely: aldrin
chlordane
DDT
dieldrin
endrin
heptachlor
mirex
toxaphene hexachlorobenzene (HCB).
Achieving the goal of Stockholm Convention
Recognizing the harm of persistent organic pollutants, many countries began to restrict or prohibit their production, use and discharge. These efforts finally led to the adoption of the Stockholm Convention on Persistent Organic Pollutants in 21 and its entry into force in 24. More than 17 parties to the convention agreed to eliminate or reduce the release of persistent organic pollutants in the environment.
The objectives of the Stockholm Convention include:
l Eliminating the production and use of specific persistent organic pollutants;
l limit the production and use of DDT within the scope of vector control according to the guidelines of the World Health Organization;
l restrict the export of persistent organic pollutants;
l develop strategies to determine the stocks of persistent organic pollutants and products containing persistent organic pollutants;
l Take measures to ensure that the wastes of persistent organic pollutants are managed and disposed of in an environmentally sound manner;
l develop strategies to identify sites contaminated by persistent organic pollutants;
l Ensure that PCBs are managed in an environmentally sound manner by 225, and take actions to eliminate the use of PCBs;
l develop and implement an action plan to identify the sources of persistent organic pollutants and reduce the release of by-products of persistent organic pollutants; And
l identify other chemicals with the characteristics of persistent organic pollutants and make them under the control of the convention.