Toxins known as perfluoroalkyl substances have become virtually ubiquitous throughout the environment, and various national and international voluntary phase-outs and restrictions on these compounds have been implemented over the last 10 to 15 years.

Investigators who examined trends in the accumulation of these toxins in the eggs of four species of aquatic birds from the Pacific coast of Canada from the early 1990s to 2011 report that the concentrations of some of these compounds are decreasing in line with manufacturing phase-outs, while others continue to increase in the oceanic environment.

Concentrations of different perfluoroalkyl substances also varied between offshore and coastal species of birds.

The findings are published in Environmental Toxicology and Chemistry.