Perfluorooctane sulfonate (PFOS) is a compound that can form a layer to repel water, grease or dirt. This enabled it to be used previously in small amounts in a number of different products, such as waterproofing agents for leather and textiles, in hydraulic systems, in fire safety products and in Teflon material.
PFOS is also considered what is called a persistent bioaccumulative and toxic substance, or PBT. “Persistent” means the substance is stable and difficult to break down in nature, “bioaccumulative” means it builds up in the food chain, and “toxic” means it is poisonous.
In the early 2000s, it was determined that highly fluorinated PBT substances were widespread in the environment. Because of its broad range of applications, PFOS, which is no longer produced in either Europe or the US, is distributed around the world.
Previous use of PFOS at Stockholm Arlanda
The reason PFOS is found in soil and water at the airport is that the substance was included in the fire extinguishing agent AFFF, which was used from some time in the 1980s until 2004-2005 in firefighting exercises at the airport’s firefighting training site.
In a survey carried out at Stockholm Arlanda Airport in 2008, the presence of PFOS was detected in places including Lake Halmsjö and the Kättstabäcken River. Since then, Swedavia has worked to increase knowledge about where PFOS is found at the airport and how it is spread and behaves. A pilot facility is in place to assess a treatment method based on activated carbon.
In 2010, samples taken from the airport’s firefighting vehicles indicated that there were still traces of PFOS in the vehicles’ tanks. As a result, in June 2011, all the firefighting vehicles at Stockholm Arlanda were decontaminated. After decontamination was completed, a new fluorine-free fire extinguishing foam (Moussol 3/6-FF) was introduced in the vehicles. The new foam forms carbon dioxide and water when it breaks down.
The RE-PATH project
The research project “Risks and Effects of the dispersion of PFAS on Aquatic, Terrestrial and Human populations in the vicinity of international airports” (REPATH) was launched in 2009, with financial backing from the Swedish Environmental Protection Agency via the IVL Swedish Environmental Research Institute and Swedavia AB.
The objective of RE-PATH, a five-year project, is to investigate and map the presence and dispersion of perfluorinated compounds and study the risks to humans and the environment as well as potential measures that can be implemented around Sweden’s main airports (Stockholm Arlanda Airport and Göteborg Landvetter Airport).
The project includes a national reference group with representatives from government authorities, companies and non-governmental organisations. A reference group meeting is held annually. The work of the project is documented in an annual report that includes both Stockholm Arlanda Airport and Göteborg Landvetter Airport.
Get the report from the project’s website (new window)
Ban on fishing in Lake Halmsjö
In 2008, Swedavia, then LFV, introduced a ban on fishing in Lake Halmsjö, which is located adjacent to Stockholm Arlanda Airport. The ban was introduced to prevent the public from ingesting PFOS by eating fish. Analyses of perch from Lake Halmsjö have shown that the fish contains elevated levels of PFOS. Translated into terms of what is acceptable for human food, the levels recorded are such that it is recommended an adult consume no more than one serving of fish (115 g) every other month.
Swimming is still permitted in Lake Halmsjö since PFOS is not absorbed through the skin. PFOS levels also mean that a few swallows of lake water are not harmful. However, the water should not be used for drinking water.
New regulations for PFOS
New national regulations for PFOS entered into force on June 27, 2008. The regulations entail a ban on the use of PFOS and other substances that can break down into PFOS in chemical products and goods. There are a few exceptions not subject to a time limit for applications in the photolithography and photography industries, chrome plating and hydraulic oils in the aviation industry. Use of fire extinguishing foam containing PFOS that was available on the market prior to December 27, 2006, was permitted until June 27, 2011.
Humans and PFOS
Humans are exposed to PFOS primarily through food and drink. It has been shown that PFOS can be transferred from mother to child through breast milk. PFOS has also been shown to affect sperm production, the functioning of the liver and cholesterol levels.
There is currently no information indicating that perfluorinated substances constitute a serious health to human health. So there is no reason for individuals to get rid of all-weather jackets, which may contain such substances. However, it is extremely important that there is no further increase of perfluorinated substances in nature, in animals or in humans.