PFAS is a relatively new group of contaminants with unique characteristics, which in the early 21

st century was understood being dangerous for both humans and the environment. In 2008, EFSA published a report on guidelines for human intake of PFAS. Target and limit values for ground and surface water around the world has been based on the information in the EFSA report. In the end of 2018, EFSA published a new preliminary report with new target values for PFAS, well below the target values published in 2008.

Frösö Park in Östersund, Sweden, is polluted by PFAS from the time that the Swedish Armed Forces were active in the area. While the Swedish Armed Forces exercised their activities at Frösö Park, large amounts of aqueous fire-fighting foams were used, mainly for training purposes. AFFF at that time contained a mixture of many highly fluorinated chemicals known as PFAS, a collective name of more than 4,700 chemicals consisting of carbon-fluorine bonds. PFAS are, more or less, persistent, bioaccumulative and toxic. This study focuses on PFAS

11, which Sweden has target and limit values for in respect of ground water and surface water (lake and sea). PFOS is the most common PFAS chemical and the most commonly occurring PFAS chemical at the Frösö Park area.