Contaminants of Concern

The Northern Contaminants Program (NCP) is concerned with contaminants that reach the Arctic via long-range transport from source areas around the globe. These include a large number of persistent organic pollutants (POPs) and heavy metals, particularly mercury. These contaminants can achieve elevated concentrations in the tissues of Arctic wildlife and present a toxicological risk to wildlife and humans who consume them.

Heavy Metals

The UNEP Minamata Convention on Mercury, a legally-binding agreement to cut emissions and releases of mercury to the environment, was formally adopted in October 2013 and entered into force on August 16, 2017, advancing an international effort to reduce global mercury pollution and protect the environment and human health. The NCP seeks annual monitoring of mercury from NCP projects as identified in the blueprints for Environmental Monitoring and Research, Human Health, and Community Based Monitoring and Research. 

Table A1. Metals of Concern for the NCP (eligible for annual sampling)

  • Mercury
  • Cadmium
  • Lead

Persistent Organic Pollutants

Most of the POPs that have been found in the Arctic environment are regulated through international agreements including the United Nations Environment Programme (UNEP) Stockholm Convention on Persistent Organic Pollutants (POPs) and the United Nations Economic Commission for Europe’s Convention on Long-range Transboundary Air Pollution (CLRTAP). Both of these Conventions routinely assess candidate chemicals and, when faced with strong evidence to suggest that a certain compound should be considered a POP, they are added to the convention annexes and regulated appropriately. These conventions rely heavily on NCP data to support the assessment of candidate POPs and to evaluate the effectiveness of the regulations at reducing POPs in the environment.

Researchers are asked to rationalize an analytical program and schedule that best suits their proposed project. Schedule A and B identify persistent organic pollutants (POPs) of concern for the NCP and are substances that are currently included in, or being considered by, international conventions. An important role for the NCP is providing monitoring data on substances that are already covered by these conventions. However, it is also very important that the NCP provide information on substances that are under consideration for inclusion in these conventions.

The 8th Stockholm Convention Conference of Parties (COP) took place in spring 2017. The COP decided to list SCCPs and decaBDE in Annex A with specific exemptions, and to list HCBD in Annex C (at the last COP, it was already listed in Annex A). The next COP will take place in April/May 2019, where decisions on the listing of dicofol and PFOA are expected (please see below), and new chemicals may be nominated for review by the technical committee, the POP Review Committee (POPRC).

The NCP participates in the annual meetings of the POPRC. In 2017, the POPRC adopted the risk management evaluation on dicofol and recommended that the COP (at their next meeting in 2019) consider listing dicofol in Annex A to the Convention without any exemptions. In 2017 and 2018, the Committee further discussed the risk management evaluation on pentadecafluorooctane sulfonic acid (PFOA), with the decision that PFOA would be recommended to be added to Annex A, with several time limited use exemptions. In 2018, POPRC also adopted the risk profile on perfluorohexane sulfonate (PFHxS) and moved the substance ahead in the review process, which means that a risk management evaluation will be compiled intersessionally and reviewed at the next POPRC meeting.

The next meeting, POPRC-15, is tentatively scheduled to take place September 30 - October 4, 2019.

For more information on the Stockholm Convention and the work of the POP Review Committee (POPRC), please visit

Schedule A: (Legacy POPs)
Compound Description of use/source
Aldrin Pesticide applied to soils to kill termites, grasshoppers, corn rootworm, and other insect pests. Used on crops such as corn and cotton. Can also kill birds, fish, and humans.
Chlordane Used extensively to control termites and as a broad-spectrum insecticide on a range of agricultural crops, such as vegetables, small grains, potatoes, sugarcane, sugar beets, fruits, nuts, citrus, and cotton.
Dieldrin Used to control termites and textile pests. Also used to control insect-borne diseases and insects living in agricultural soils.
DDT Insecticide used on agricultural crops, primarily cotton, and insects that carry diseases such as malaria and typhus.
Endrin Insecticide sprayed crops such as cotton and grains. Also used to control rodents such as mice and voles.
Mirex Insecticide used to combat fire ants, termites, and mealybugs. Also used as a fire retardant in plastics, rubber, and electrical products.
Heptachlor Insecticide used against soil insects and termites. Also used against some crop pests and to combat malaria.
hexachlorobenzene (HCB) Kills fungi (e.g. wheat bunt) that affect food crops. Also an industrial chemical used to make fireworks, ammunition, synthetic rubber, and other substances; a by-product of the manufacture of certain industrial chemicals; and an impurity in several pesticide formulations.
PCBs Used for a variety of industrial processes and purposes, including electrical transformers and capacitors, heat exchange fluids, paint additives, carbonless copy paper, and plastics.
Toxaphene Insecticide used on cotton, cereal grains, fruits, nuts, and vegetables. Also used to control ticks and mites in livestock.
polychlorinated dibenzo-p-dioxins (PCDD) Produced unintentionally due to incomplete combustion, and during the manufacture of pesticides and other chlorinated substances. Emitted mostly from the burning of hospital, municipal, and hazardous waste; and from automobile emissions, peat, coal, and wood.
polychlorinated dibenzofurans (PCDF) Produced unintentionally from many of the same processes that produce dioxins, and also during the production of PCBs. Have been detected in emissions from waste incinerators and automobiles.
Schedule B: (New and Emerging POPs)
Compound Description of use/source
alpha hexachlorocyclohexane (alpha-HCH) Intentional use as an insecticide was phased out but this chemical is still produced as an unintentional by-product of lindane.
beta hexachlorocyclohexane (beta-HCH) Intentional use as an insecticide was phased out but this chemical is still produced as an unintentional by-product of lindane.
chlordecone Agricultural pesticide
hexabromobiphenyl Flame retardant
hexabromocyclododecane (HBCD) Used as a flame retardant, providing fire protection during the service life of vehicles, buildings or articles, as well as protection while stored. Main global use is in polystyrene foam insulation, and in textile applications and electric and electronic appliances.
hexabromodiphenyl ether and heptabromodiphenyl ether Flame retardant
lindane Broad-spectrum insecticide for seed and soil treatment, foliar applications, tree and wood treatment, and against ectoparasites (e.g. fleas and lice) on people and other animals.
pentachlorobenzene (PeCB) Was used in PCB products, dyestuff carriers, as a fungicide, a flame retardant, and as a chemical intermediate. Also produced unintentionally during combustion, thermal and industrial processes, and present as impurities in products such as solvents or pesticides.
perfluorooctane sulfonic acid (PFOS), its salts and perfluorooctane sulfonyl fluoride (PFOS-F) PFOS is both intentionally produced and an unintended degradation product of related manmade chemicals. The current intentional use of PFOS is widespread and includes: electric and electronic parts, fire fighting foam, photo imaging, hydraulic fluids, and textiles.
endosulfan and its related isomers Insecticide used since the 1950s to control crop pests, tsetse flies, ectoparasites of cattle, and as a wood preservative. As a broad-spectrum insecticide, endosulfan is currently used to control a wide range of pests on crops including coffee, cotton, rice, sorghum, and soy.
tetrabromodiphenyl ether and pentabromodiphenyl ether (commercial pentabromodiphenyl ether, or PBDE) Used as a flame retardant
Pentachlorophenol (PCP) and its salts and esters Used as a wood preservative in the 1930s and has had a variety of other applications (e.g. biocide, insecticide, fungicide, disinfectant, defoliant, anti-sapstain agent and anti-microbial agent). It has been also used in the production of textiles.
polychlorinated naphthalenes (PCNs: di, tri, tetra, penta, hexa, hepta, octa) Used in wood preservation, as additive to paints and engine oils, and for cable insulation and in capacitors
Hexachlorobutadiene (HCBD) Is mainly created as a by-product in the manufacture of chlorinated hydrocarbons like tri- and tetrachloroethene and tetrachloromethane and was/is used as a fumigant.
PFOA Used either in direct applications in the production of fluoroelastomers and fluoropolymers, with polytetrafluoroethylene (PTFE) being the most important fluoropolymer. PFOA-related substances are used in fire-fighting foams, wetting agents and cleaners. In textiles and leather, paper and cardboard (e.g. food packaging), paints and lacquers and other uses (non-woven medical garments, floor waxes and stone/wood sealants, thread sealant tapes and pastes, adhesives, products for apparel) side-chain fluorinated polymers are used.
Dicofol An organochlorine pesticide that is chemically related to DDT. The substance is a miticidal pesticide and acaricide used in many countries around the world on a wide variety of fruit, vegetables, ornamental and field crops.
Short-chained chlorinated paraffins (SCCPs) Used in metal working fluids, sealants, as flame retardants in rubbers and textiles, in leather processing and in paints and coatings.
Deca-BDE Used as an additive flame retardant, and has a variety of applications including in plastics/ polymers/composites, textiles, adhesives, sealants, coatings and inks. Also used in housings of computers and TVs, wires and cables, pipes and carpets. It is used in commercial textiles, mainly for public buildings and transport, and in textiles for domestic furniture.