They have no known taste or smell, and range in consistency from thin, light-coloured liquids to yellow or black waxy solids. Due to their non-flammability, chemical stability, their resistance to acids and bases as well as to heat, PCBs have been used in hundreds of industrial and commercial applications such as plastics, paints, adhesives, surface coatings, inks, electric equipment, heat transfer fluids and lubricants. Their commercial production started in 1929 but their use has subsequently been banned or severely restricted in many countries since the 1970s and 80s because of the possible risks to human health and the environment: PCBs are toxic, carcinogenic, neurotoxic, and known to be endocrine disruptors.
They do not really break down once in the environment. PCBs are ubiquitous and persistent pollutants: half-life goes from 94 days to 2,700 years depending on the molecules. The atmosphere serves as the primary route for global transport of PCBs. They can remain for long periods cycling between air, water and soil. In rivers and lakes, they stick to sediments, where they can remain buried for a long time before being eventually released into water and air. PCBs in the air can reach the ground with falling rain and snow, or simply when suspended particles settle with gravity. They can be carried long distances and have been found in snow and sea water in areas far from where they were released into the environment. As a consequence, they are found all over the world.
Generally, PCBs are not very soluble in water, but readily soluble in fats. This solubility in fat explains why, like many lipiphilic toxins, PCBs bio-magnify up into the food chain: they accumulate in animals’ fatty tissues and along the food-chain. Humans can also accumulate PCBs by ingesting contaminated food and water or inhaling contaminated air. They can also be measured in many biological samples, such as human blood, milk, as well as in some foods such as animal tissues, fish and dairy products, or in several environmental samples, such as in air, drinking water, soil, sediment, and solid waste.
The Polarquest team carried out microplastic sampling across the Arctic, using the Mantanet. Learn about how the team collected these samples in “Recipe: How to sample microplastics in the ocean”.
Water samples were collected in the top 16 cm of surface water and sub-surface samples from the vessel’s on-board seawater pump, situated 6 m below the surface. This will allow for future microplastic monitoring and to a risk assessment of the potential impacts of decreasing sea ice, increasing shipping and commercial activity.
A total of 30 microplastic sampling stations were carried out, with one at the record latitude of 82°07 N, right on the edge of the ice, by 19-year-old microplastic operator Safiria Buono. The samples will be analyzed by the Marine Institute (ISMAR) of CNR (National Research Council of Italy), but “one of the conclusions which can already be drawn from a simple visual check is that, even at these high latitudes, the quantity of macro plastic loitering the most remote and wildest beaches of our planet is astonishing” she says. “A piece of plastic was caught in the Mantanet even at 82°N!”
Safiria describes more of her experiences sampling microplastics in the Arctic in “Dispatch from Nanuq: taking the Northern-most microplastics sample”. Look forward to more scientific results from this project, as analysis is ongoing on the samples.
Find out more:
- Read about Nanuq’s 2016 microplastics sampling campaign.
- Read the August 2018 dispatch from Nanuq: taking the Northern-most microplastics sample
- Read the July 2018 dispatch from Nanuq: “Even out in the Arctic waters, plastic is all too common”
- Read our feature article on Nanuq’s search for the 6th microplastic island, in the Arctic ocean.
- Contribute to Polarquest2018 Microplastic campaign.