These substances are called 'forever chemicals' because they break down very slowly in the natural environment. Some people may know them by the abbreviation PFAS, which stands for per- and polyfluoroalkyl substances. They are also very abundant.

"These substances are used in hundreds of products, ranging from frying pans and waterproof clothing to firefighting foam, food packaging and stain-resistant coatings," explained Anne-Fleur Brand, who until recently was a Ph.D. research fellow at the Norwegian University of Science and Technology (NTNU).

As a result, PFAS can be found across large parts of the world. They have been found in drinking water and in cross-country ski tracks because PFAS was previously used in ski wax. It is a large group of chemicals, and some of them have already been prohibited because they are so toxic. But not all of them.

"Thousands of forever chemicals are still in use," said Brand.

Little is known about their harmful effects, but researchers have now discovered that these substances can harm ducklings even before they have hatched.

Investigating PFAS effects in duck eggs

"We studied two new PFAS chemicals that were recently found in wild duck eggs. These chemicals are known to exist in the natural environment, but very little is documented about their effects," said Professor Veerle Jaspers at NTNU's Department of Biology. The paper is published in the journal Environmental Toxicology and Chemistry.