260 likes | 954 Views
Persistent Organic Pollutants (POPs). What are the POPs?
E N D
Persistent Organic Pollutants (POPs) What are the POPs? Persistent Organic Pollutants (POPs) are the substances characterized by combination of unique properties like semi-volatility, persistence, toxicity, bioaccumulation, and long-range transport potential. POPs can persist in the environmental compartments for years and decades, disperse globally, bioaccumulate in food chains, and pose threat to humans and wildlife. Most of POPs are lipophilic which causes their accumulation in fatty tissues of living organisms and biomagnification up to the harmful level of concentrations. observations POLICY effects assessment emission inventories modeling Efforts to limit POPs dispersion and effects • Convention on Long-range Transboundary Air Pollution (CLRTAP) was signed in 1998 and came into force in 2003. • The Stockholm Convention on POPs of United Nations Environment Programme (UNEP) was adopted in 2001 and entered into force in 2004. • Nowadays 36 countries signed the CLRTAP POP Protocol and more than 170 countries become Parties to the Stockholm Convention. EMEP monitoring network for POPs Observations are essential for policy making
Emisisons of POPs Comparing to other pollutants most of POPs are of anthropogenic origin only. Main sources of POPs are combustion and industrial processes, waste incineration, transport, and agriculture. Spatial distribution of B[a]P emissions in 2009 over the EMEP domain (left) and contributions of different sectors to total annual emission (right) Following measures performed by Parties to reduce unintentional releases of POPs their emissions substantially decreased in the period from 1990 to 2009. According to available official information and expert estimates, emissions of benzo[a]pyrene, PCDD/Fs, and HCB dropped by almost 30%, 60%, and 80%, respectively. Task Force for Emission Inventories
What mechanisms control POPs ? As a result of anthropogenic activities POPs can be released to air, soil, and water compartments. Entering the environment they are dispersed globally by the atmospheric and water flows and partition to and accumulate in other media (soil, snow, vegetation, sediments, etc.). Measurements indicated their presence in the remote regions far away from industrial or agricultural areas where they were released. Modeling tools are used to obtain spatial and temporal distribution of POPs In the framework of EMEP monitoring of pollution levels and trends is accompanied by modeling data on POP transboundary transport, concentrations and deposition. For this purpose EMEP multi-scale multi-compartment modeling system GLEMOS is applied. GLEMOS is capable to evaluate spatial distribution of POP pollution levels in different media (air, soil, seawater etc.) and transboundary fluxes on global, regional, and local scales. Besides, it provides estimates of POP fluxes from different media to the air (re-emission). Task Force for Measurements and Modeling
Effects of POPs on Enviromment Ways of exposure and adverse effects of POPs Exposure to persistent organic pollutants takes place through diet (specifically, consumption of animal fats), environmental exposure or accidents. There are known adverse effects of exposure to high levels of POPs in humans and wildlife that may include cancer, damage to the nervous system, reproductive disorders, or disruption of the immune system. Besides there is increasing concern that chronic exposure to low levels of POPs may contribute to the burden of disease leading to various health problems. http://www.npolar.no Working Group on Effects