Krishna Das is interested in the eco-toxicology of marine vertebrates. In other words all the vertebrates that impact on the marine environment: fish, birds, turtles and mammals. She has just begun, together with German colleagues, a study of the pied oystercatcher, whose population in the Wadden sea is decreasing. The reason might be changes in their diet, but we will have to wait some years before indisputable proof of it can be presented.

In an article (1), published this Summer by Environmental Science & Technology, and written with Brazilian colleagues and colleagues at the University of Antwerp, Krisha Das gives an account of an alarming phenomenon: the arrival of new pollutants in certain animals. The research is based on Brazil’s Tucuxi dolphins, little ‘flippers’ of which a colony live in the Bay of Rio. These animals are particularly studied, tracked and spied upon at every moment by Brazilian scientists because they are recognized as a sentinel species. Difficult for them to be otherwise: the bay of Rio, around which 11 million people are crushed, is one of the most polluted places in the world. Analysis has shown that new pollutants reach the end of the chain, notably these little Brazilian dolphins. These pollutants are primarily flame retarders (substances which contain bromine atoms), present everywhere in our society: in furniture, in paint, in fabrics, etc. They act within the marine environment in the same way as PCBs acted, substances which were much talked about thirty years ago. They are even found in the Arctic zones. The same goes for certain fluoride compounds such as Teflon, which end up being discovered in food and then within our bodies. Other fluoride compounds are found in anti-stain products, in packaging materials and in solvents. They have also migrated into marine mammals, including the famous Tucuxi dolphin, at the peak of the food chain, as is shown by the study published in Environmental Science & Technology. It is thus suspected that their concentrations will only increase in the coming years. That includes human beings: we are already finding traces of them in our blood serum and in our fats.

(1) Dorneles P, Lailson-Brito J, Azevedo AF, Meyer J, Vidal LG, Fragoso AB, Torres JP, Malm O, Blust R, Das K. High Accumulation of Perfluorooctane Sulfonate (PFOS) in Marine Tucuxi dolphins from Brazilian coasts. Environmental Science & Technology 42 (14): 5368-5373