Perfluorinated substances have been used for about 50 years in surface finishes of textiles, cleaning agents, kitchen utensils and firefighting agents as well as to coat food packaging, for example.
PFOS (perfluorooctane sulfonate) is one of the most widely known substances and has been used for firefighting foam, among other things. In recent years, it has been found that PFOS can be harmful to animals. There may also be a risk of it being harmful to humans, although no such harm has been identified so far. We all have some level of PFOS in us from the food we eat and sometimes from different chemical products that enter our system in a different way. PFOS can therefore be measured, for example, in our blood.
Elevated concentrations of PFOS have been identified in water and fish from West Ingsjö Lake and in water from East Ingsjö Lake. There is a high probability that this can be connected to the firefighting exercise site at Göteborg Landvetter Airport, where firefighting foam containing PFOS was used in the 1990s for firefighting exercises. The firefighting pond has now been emptied and decontaminated, but since PFOS breaks down slowly, there can still be elevated concentrations in the environment and in fish.
PFOS research project
A research project on PFOS in the environment was conducted over a five-year period. The RE-PATH project is aimed at investigating and mapping the presence, spread and risks of PFOS to people and the environment and at exploring potential measures for perfluorinated substances around Göteborg Landvetter Airport and elsewhere. The project is funded by Swedavia and the Swedish Environmental Agency and is being conducted by IVL, Svenska Miljöinstitutet AB.
It has been concluded from the project that adults can eat fish caught in West Ingsjö Lake up to 7 times a month without exceeding the established benchmark level. Following the precautionary principle, women who are pregnant or breast-feeding are advised not to eat fish from the lake.
Annual report for the research project
At the request of Göteborg Landvetter Airport and the environmental management organisations in the municipalities of Härryda and Mölndal, VMC (Västra Götalandsregionens Miljömedicinska Centrum), a unit at Sahlgrenska University Hospital, investigated whether PFOS in fish led to a measurable increase in concentration in the blood serum of nearby residents who eat a lot of fish from the lakes in question.
Comparisons were also made with control groups of people from different areas as well as of people living in the same areas who have not eaten such fish. An assessment was also made of the risks of any effect on people’s health.
The conclusion was that there was no such risk, and two reasons were given. First, the people studied had lower intakes of PFOS than the EU considers to be a risk-free level. Second, the people in the study have much lower levels than groups who, for example, are or have been exposed to PFOS in their work without it having been possible to determine that there was any effect on their health.
Measures at the airport
Since 2008, the airport has treated the most contaminated groundwater at its firefighting exercise site. In 2010, a permanent facility was set up to prevent the further spread of PFOS from the airport. Surface water and shallow groundwater that pass through the contaminated area are collected in a lined trench and conveyed to two reinforced ponds for further treatment in a carbon filter facility intended to clean water contaminated with PFOS. In 2017 the carbon filter facility was expanded so that it consists of a series of carbon filter columns for more effective treatment. After the water is cleaned, it is conveyed to the airport’s surface water ponds.
In 2011, all firefighting vehicles at the airport were decontaminated. After the decontamination work was completed, a new fluorine-free firefighting foam was introduced, Moussol 3/6-FF, in firefighting vehicles. The new foam forms carbon dioxide and water when it is broken down.
National Swedish PFOS regulations entered into force on June 27, 2008. The new regulations entail a ban on the use of PFOS and on substances that can be broken down into PFOS in chemical products and goods. There are some exceptions, which are not limited in time, for certain applications in the photolithography and photography industry, in chrome plating and in hydraulic fluids for aviation. Since 2011, firefighting foam that is free from fluorinated substances is used at Swedavia’s airports.