Atmospheric transport of pollutants to the Barents Sea

The research park at Longyearbyen, Svalbard, on a sunny winter day.
Photo: Kim Holmén / Norwegian Polar Institute

Environmental pollutants are carried to the Barents Sea by both air and ocean currents, but the atmosphere is the fastest, most efficient mode of transport. The primary sources of the contaminants measured in the air are therefore found outside of the Arctic. For many years, a number of pollutants have been on the decline. In recent years, this trend has stagnated, and in some cases the transports have increased somewhat.

What is being monitored?

Pollution in air in Svalbard

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Annual mean concentration of HCB in the atmosphere at the Zeppelin Observatory. The figure shows how atmospheric HCB in Svalbard has increased in the last ten years.

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Annual mean concentration of all PAHs in the atmosphere at the Zeppelin Observatory. The figure shows that the annual mean concentration of atmospheric PAHs had a clear declining trend from 1998 to 2006. Subsequently, the levels have been relatively stable, with some annual variation and increased levels in 2013 and 2014. The peaks in some years are primarily due to single elevated episodes.

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Annual mean concentration of all PCBs in the atmosphere at the Zeppelin Observatory. The figure shows atmospheric PCBs at the Zeppelin Observatory. The long-term trend is for the levels to have fallen, but here too there are annual variations.

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Annual mean concentrations at the Zeppelin Observatory. The figure shows that the concentrations vary from year to year and no clear trend can be discerned.

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Annual mean concentration at the Zeppelin Observatory. The figure shows that there has been little change in atmospheric mercury in Svalbard since 2000. This contrasts markedly with observations at lower latitudes, which show a declining trend.

Status and trend

In 2015, the concentrations of PCBs, PAHs and most pesticides measured in the air at Zeppelin were at the same level as or lower than in previous years. The levels of PCBs and brominated flame retardants (PBDE) vary from year to year, and no clear trends are discernible. PFASs and HBCD are mainly below the detection limit and no clear trends can be discerned.

Most of the PFAS compounds measured in Svalbard are below the analytical detection level; in other words, the levels are so low that they are not shown by the measurements. PFOS, PFOSA and PFOA are the compounds that are measured above the detection level more than any others.

The level of mercury measured in the air in Svalbard varies throughout the year. In winter, contaminated air is transported from western, central and eastern regions of Europe northwards, resulting in higher levels of mercury in the air in Svalbard. The levels are also high in summer. The cause is evaporation of mercury from the ocean, because the sea ice melts. In spring, episodes of high mercury levels in the air are much reduced. This is due to processes in the atmosphere that convert mercury to more reactive compounds that are deposited on the ground, the ice or the ocean surface. The majority of the mercury will evaporate back into the atmosphere. A small proportion will end up in sediments, the soil, lakes and in the ocean. Algae and bacteria can convert mercury into highly toxic methylmercury, which is how the mercury enters the food chain. Fish and mammals high up in the food chain bioaccumulate methylmercury through their food intake.

Causal factors

The concentrations of airborne pollutants in Svalbard are affected by emissions of pollutants in different parts of the world, with Europe and Asia making the greatest contributions. The concentrations are also affected by climatic conditions that impact the atmospheric modes of transport.

Consequences

Climate change with increased temperatures is expected to cause intensified dispersal of pollutants globally. The melting of sea ice and thawing of permafrost may cause the remobilisation and evaporation of pollutants into the atmosphere in the Arctic. Large forest fires and cropland burning have been shown to increase the transport of organic pollutants to the Arctic. Increased local industrialisation (such as oil and gas activities and mining) and shipping in the High North may contribute to increased transport of some of the pollutants measured in the air in Svalbard.

The transport and levels of many of the pollutants measured in the air in Svalbard have continued to fall, but for some pollutants there have been slight increases in recent years. Causes are assumed to be continued use of environmental pollutants in different parts of the world, and pollutants being released from previous deposition in the environment by rising temperatures. Mercury levels have been stable since 2000.

About the monitoring

The monitoring is performed as part of the “Long-range transported pollutants in air and precipitation” programme under the Norwegian Environment Agency. The Norwegian Institute for Air Research (NILU) performs the monitoring and also contributes results from its own measurement programme.

Places and areas

Relations to other monitoring

Monitoring programme
International environmental agreements
Voluntary international cooperation
Related monitoring
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