Features
- Persistence: POPs resist degradation in the environment, remaining active for years or even decades.
- Bioaccumulation: They accumulate in the fatty tissues of living organisms, increasing in concentration as they move up the food chain. This process, known as biomagnification, can lead to high levels of POPs in top predators, including humans.
- Long-Range Transport: POPs can travel long distances through the atmosphere, contaminating areas far from their source.
- Adverse Effects: POPs can cause various health problems, including cancer, birth defects, developmental problems, and immune system dysfunction.
Sources
- Industrial Processes: Production of pesticides, industrial chemicals, and unintentionally produced POPs released during combustion processes. (e.g., incineration)
- Obsolete Stockpiles: Outdated pesticides and industrial chemicals stored improperly can leak into the environment.
- Waste Disposal Practices: Open burning of waste and inadequate landfill management can release POPs.
Types
- Dichlorodiphenyltrichloroethane (DDTs): Once widely used insecticides, now banned or restricted due to their environmental persistence and bioaccumulation.
- Aldrin and Dieldrin: Former insecticide chemicals with similar environmental concerns as DDT.
- Hexachlorobenzene (HCB): A fungicide with POP characteristics.
- Mirex: A now-banned insecticide known for its toxicity and environmental impact.
- Polychlorinated Biphenyls (PCBs): Industrial coolants, lubricants, and electrical insulators, phased out due to their hazardous nature.
- Polychlorinated Dibenzo-p-dioxins (PCDDs) and Polychlorinated Dibenzofurans (PCDFs): Unintentional byproducts of combustion processes and some industrial activities.
- Perfluorooctane Sulfonate (PFOS) and Perfluorooctanoic Acid (PFOA): Man-made chemicals used in various industrial applications, raising concerns about their persistence and health effects.
Conventions
- Stockholm Convention on POPs – International treaty enacted in 2004 to eliminate or restrict the production and use of POPs.
- Basel Convention on the Control of Transboundary Movements of Hazardous Wastes and Their Disposal – It’s an international treaty, entered into force in 1992 to prevent the transfer of hazardous waste from developed to less developed countries (LDCs) unless the waste is destined for recycling or disposal in an environmentally sound manner
- Rotterdam Convention on Prior Informed Consent Procedure for Certain Hazardous Chemicals and Pesticides in International Trade – It is a multilateral treaty and the convention promotes an open exchange of information and calls on exporters of hazardous chemicals to use proper labelling, and safe handling, and inform purchasers of any known restrictions or bans. Signatory nations can decide whether to allow or ban the importation of chemicals listed in the treaty