Glossary
Airborne Transport
The movement of POPs through the atmosphere, carried by wind currents as gases or attached to particulate matter, enabling their global distribution.
Example:
Fine dust particles carrying POPs can undergo airborne transport across continents before settling in new locations.
Annex A (Stockholm Convention)
A list within the Stockholm Convention that identifies POPs for elimination, meaning their production and use are banned by signatory parties.
Example:
DDT is listed under Annex A of the Stockholm Convention, indicating its global ban for most uses.
Annex B (Stockholm Convention)
A list within the Stockholm Convention that identifies POPs for restriction, allowing their production and use only for specific, limited purposes.
Example:
Some POPs might be found in Annex B if they have critical, limited uses, such as for disease vector control, but are otherwise restricted.
Annex C (Stockholm Convention)
A list within the Stockholm Convention that identifies unintentionally produced POPs, such as dioxins and furans, and requires parties to reduce or eliminate their releases.
Example:
Industrial processes that inadvertently create POPs are addressed under Annex C, which mandates efforts to minimize their formation and release.
Bioaccumulation
The gradual build-up of a substance, such as a POP, in an individual organism's tissues over its lifetime, as the rate of intake exceeds the rate of excretion.
Example:
A single fish continually ingesting small amounts of mercury will experience bioaccumulation as the metal concentrates in its body over months.
Bioaccumulative
A characteristic of POPs indicating their tendency to build up in the tissues of individual organisms over time, often in fatty tissues, because they are not easily metabolized or excreted.
Example:
A fish consuming contaminated plankton will experience bioaccumulative effects as the POPs build up in its body throughout its lifespan.
Biomagnification
The increasing concentration of a substance, such as a POP, in the tissues of organisms at successively higher trophic levels in a food chain.
Example:
Eagles at the top of the food chain exhibit biomagnification of DDT, leading to much higher concentrations in their bodies than in the insects or fish they consume.
Chlordane
An organochlorine insecticide once widely used for termite control, now banned due to its persistence, bioaccumulative nature, and neurological and carcinogenic effects.
Example:
Homes treated with Chlordane for termite infestations decades ago may still have residual contamination in the soil.
Combustion
The process of burning, which can release POPs like dioxins and furans as byproducts, especially from incomplete burning of waste or industrial materials.
Example:
Improper waste incineration can lead to the release of harmful POPs through combustion byproducts into the atmosphere.
Conference of the Parties (COP)
The governing body of the Stockholm Convention, comprising representatives from all signatory nations, which meets regularly to review and assess the Convention's implementation and make decisions.
Example:
During the annual Conference of the Parties, new chemicals may be added to the list of banned or restricted POPs under the Stockholm Convention.
DDT
Dichlorodiphenyltrichloroethane, a synthetic organochlorine insecticide widely used in the past but now banned in many countries due to its persistence and harmful effects on wildlife, particularly birds.
Example:
The widespread use of DDT in the mid-20th century led to severe eggshell thinning in birds of prey, threatening their populations.
Deposition
The process by which airborne POPs settle out of the atmosphere onto land or water surfaces, contributing to their accumulation in ecosystems.
Example:
After traveling long distances, atmospheric POPs undergo deposition onto snow and ice in polar regions, where they can then enter the food web.
Dioxins
A group of highly toxic chemical compounds, primarily byproducts of industrial processes like waste incineration and chemical manufacturing, known for their carcinogenic and endocrine-disrupting effects.
Example:
Accidental release of dioxins from industrial accidents has caused severe health problems and environmental contamination in affected areas.
Endocrine Systems
A network of glands and organs that produce and release hormones, which regulate various bodily functions; POPs can disrupt these systems, leading to hormonal imbalances.
Example:
Exposure to certain POPs can interfere with an animal's endocrine systems, potentially causing reproductive issues or developmental abnormalities.
Fat-soluble
A property of POPs meaning they dissolve readily in fats and oils rather than water, which explains their tendency to accumulate in the fatty tissues of organisms.
Example:
Because DDT is fat-soluble, it readily accumulates in the adipose tissue of animals, leading to higher concentrations over time.
Hexachlorobenzene (HCB)
A fungicide and industrial chemical classified as a POP, known for its persistence in the environment and its potential to cause liver and kidney damage and cancer.
Example:
Farmers using Hexachlorobenzene as a seed treatment unknowingly introduced a persistent pollutant into agricultural ecosystems.
Industrial Sources
Origins of POPs related to manufacturing processes, chemical production, or the use of industrial chemicals.
Example:
The production of electrical transformers historically led to industrial sources of PCBs, which then entered the environment.
Legacy Sources
Environmental reservoirs of POPs that remain from past production, use, or disposal, continuing to release these chemicals into the environment even after their ban.
Example:
Old landfills containing industrial waste can act as legacy sources, slowly leaching PCBs into groundwater decades later.
Long-Range Transport
The movement of POPs over vast distances through atmospheric and oceanic currents, allowing them to contaminate regions far from their original source, including remote polar areas.
Example:
Long-range transport explains why POPs produced in industrial regions can be found in the tissues of Arctic wildlife.
PCBs
Polychlorinated biphenyls, a group of industrial chemicals once used in electrical equipment and other products, now banned due to their persistence, toxicity, and links to cancer and developmental issues.
Example:
Contamination of the Hudson River by PCBs from industrial discharges led to long-term fishing bans and health advisories.
Persistent
A characteristic of POPs meaning they do not easily break down in the environment through natural processes like sunlight, water, or microbial action. This allows them to remain in ecosystems for decades.
Example:
The persistent nature of DDT meant it lingered in soils and water bodies long after its use was banned, continuing to affect wildlife.
Persistent Organic Pollutants (POPs)
Harmful organic chemicals that resist environmental degradation, persist in the environment for long periods, and can travel globally. They pose risks to human health and ecosystems due to their persistence, bioaccumulation, and toxicity.
Example:
The widespread presence of Persistent Organic Pollutants like PCBs in polar bears demonstrates their ability to travel far from their original sources and accumulate in remote ecosystems.
Pesticides
Chemicals designed to kill or control pests, some of which, like DDT and chlordane, are classified as POPs due to their persistence and harmful effects.
Example:
The widespread use of pesticides like DDT in the mid-20th century had devastating impacts on bird populations due to eggshell thinning.
Stockholm Convention
An international environmental treaty signed in 2001 that aims to eliminate or restrict the production, use, and release of persistent organic pollutants globally.
Example:
The Stockholm Convention represents a global commitment to phasing out the most dangerous 'forever chemicals' to protect human health and the environment.
Toxic
A characteristic of POPs meaning they are poisonous or harmful to living organisms, even at low concentrations, causing adverse health effects.
Example:
The toxic effects of dioxins can include developmental problems and immune system suppression in exposed animals.
Waterborne Transport
The movement of POPs through aquatic systems, such as rivers, lakes, and oceans, either dissolved in water or adsorbed to sediments.
Example:
Runoff from agricultural fields can lead to waterborne transport of banned pesticides into nearby streams and eventually the ocean.