Phase-out of fluorinated chemicals – EviEM launches scoping study

NEWS | 2013-02-22

Poly- and perfluorinated alkylated substances (PFASs) have been released into the environment across large areas of the world. Since several PFASs are toxic and slow to degrade, it is desirable to halt their release, and in some countries two of these compounds have begun to be phased out. EviEM, together with Cynthia de Wit at Stockholm University, is now launching a more in-depth scoping study of the phase-out of PFASs.

Widely used for many years

Poly- and perfluorinated alkylated substances do not occur naturally, but have been produced and used in commercial products for over 60 years. They are used, for instance, in water-, dirt- and stain-repellent treatments for clothes and carpets, and in fire-fighting foams, paints and adhesives. PFASs also have uses in industry, for example as surfactants and emulsifiers. Two different PFASs, perfluorooctane sulphonate (PFOS) and perfluorooctanoic acid (PFOA), have now started to be phased out in certain parts of the world, but elsewhere their manufacture and use continue. At the same time, the use of replacement compounds such as perfluorobutane sulphonate (PFBS) is increasing.

Concentrations in the environment pose a risk

Many PFASs are very persistent (slow-degrading), at the same time as they are readily absorbed by living organisms and highly toxic. In addition, they can be transported over long distances, by marine currents or in the atmosphere. According to a report published by the Swedish Environmental Protection Agency in 2012, PFAS levels in the aquatic environment are so high that they pose a risk of liver damage and reproductive disorders in seals and otters. Birds, too, could suffer reproductive disturbances. In some Swedish peregrine falcon eggs, PFOS has been found at concentrations which other studies show can cause adverse effects, and average concentrations in eggs of the species are very close to this harmful level.

Difficult to interpret the findings

Observed temporal trends for PFASs in the environment can be difficult to interpret, and in some cases they are contradictory. In Sweden, PFOS levels have recently risen in peregrine eggs, but remain unchanged in grey seal livers and are falling in the livers of otters. It is therefore not entirely easy to tell whether the situation is still deteriorating overall, or whether the partial phase-outs have started to have an effect. A less desirable consequence of the phase-out is that releases of the replacement chemical PFBS are increasing. In blood serum from first-time mothers in Uppsala, PFBS concentrations have risen sharply.

A need for synthesis and analysis

To get a clearer picture of the occurrence of different PFASs in the natural environment, the Swedish Chemicals Agency has expressed a need for a synthesis and analysis of internationally available data and an evaluation of temporal trends. Such a synthesis could serve as an important input into the agency’s national and international efforts to reduce the use of PFASs. At present, only PFOS, for example, is included on the Stockholm Convention’s list of persistent organic pollutants (POPs) and the OSPAR Commission’s list of chemicals for priority action. A comparison of temporal trends in different parts of the world, both where phase-out has occurred and where it has not, and close to different sources as well as in remoter areas, could in addition provide new knowledge about these substances’ transport pathways and properties in the environment.

Scoping study by Mistra EviEM

Mistra EviEM, in collaboration with Professor Cynthia de Wit of Stockholm University, will now study what type of evidence base there is in this area, how extensive it is, and how it could be reviewed. The study is intended to form a basis for assessing the feasibility of a full systematic review of the question: ‘What effect do non-global phase-outs of poly- and perfluorinated alkylated substances (PFASs) have on the occurrence of these compounds in the atmospheric and aquatic environment?’ Project manager at Mistra EviEM is Magnus Land.