Chemicals in rainwater - a health risk

The levels of the "forever chemicals" PFAS in rainwater exceed the limit for what is considered harmful in most parts of the world.

A new study from Stockholm University states that there is nowhere on earth where it can be avoided.

Regn är bara ett sätt att bli exponerad för PFAS. Arkivbild.
Rain is one way to be exposed to PFAS. Archive image.

A research group at the Department of Environmental Sciences and Analytical Chemistry has compared the levels of four perfluorinated alkyl acids in nature with the limit values set for how much is safe to eat. The amounts in rainwater exceed the limit values for drinking water in most parts of the world.

The levels are by nature the highest where humans live, that is where chemicals are used and released, but the PFAS is everywhere.

The snow in Antarctica has higher levels of PFAS than what was put for drinking water in USA," says Professor Ian Cousins, who led the study published inEnvironmental Science and Technology.

Limit values reduced

PFAS has been used since the 1950s and the levels in nature have been the same for the last 20 to 30 years. The limit values have been greatly reduced as they learned more about how exposure to PFAS affects us.

It's only now that we've learned more about the toxicity and the reduced safety levels, but we've been exposed all along.

Ian Cousins has reviewed over time how the limit values were lowered and approached the levels found in the rainwater.

In fact, the limit values are now below the levels found in the environment, and it has become impossible to reach the limit values.

Chemicals with the collective name PFAS are everywhere in our everyday life, for example in frying pans, food packaging, all-weather clothing and make-up.

Worse immune system

They are often called eternity chemicals because they are not broken down in nature. They are also stored in the body of both animals and humans. More and more research indicates that even low levels of PFAS are harmful to us.

What you base the limit values on is that you get less immune response from being exposed. You have less ability to form antibodies, says Ian Cousins.

At the same time, it is difficult to prove the effects of PFAS," he adds.

There's no control population because everyone's been exposed.

The researchers behind the study want to see that the use of PFAS be rapidly phased out and emissions severely limited.

We must learn from this and not release persistent substances – and there are many such chemicals. If you release substances that never decompose, there will be high concentrations in the environment. If you find that there are problems with them, it is very difficult to clean the water and the soil and remove them.

Facts: PFAS

PFAS, which stands for per- and polyfluorinated alkyl acids, began to be produced on a larger scale in the 1950s. There are approximately 4,700 different PFAS substances.

The PFAS molecules have special surface properties, which are used to make sustainable bubbles in fire foam, good glide in ski wall and water repellent impregnation for textiles, as well as in food packaging and frying pans.

In Sweden, we ingest low levels of PFAS mainly through food, for example fish from polluted lakes, and from indoor air as the substances are spread from gadgets and materials in our homes.

Through the use of products or goods treated with PFAS, the substance can also be absorbed through the skin.

People have also been exposed to higher levels in areas where drinking water has been contaminated with PFAS, for example from fire training sites.

PFAS can also be transmitted to the foetus via the placenta, and to babies via breast milk.

Source: Swedish Chemicals Inspectorate and Karolinska Institutet.