The marine fauna does not suffer only the consequences of pieces of plastic that they ingest, but of the chemical compounds that they give off. A study of Superior Council of Scientific Research (CSIC), made in samples of 11 dolphins found dead in the Alboran Sea, has located traces of substances such as flame retardants and plasticizers called organophosphates. The substances were found in the fat, muscle, liver or brain of the specimens, reaching concentrations of up to 25 micrograms per gram of fat. Ethel Eljarrat, CSIC scientist responsible for the work, indicates that they have "been surprised by the high levels of these substances detected for the first time in marine mammals, although they had already been found in river fish."
Scientists think that the presence of these products in dolphins is probably due to their body accumulating them after the ingestion of plastic. A fact that indicates the need to evaluate "not only physical damage, but also its chemical impact". Ranaud de Stephanis, from the association of Conservation, Research and Study of Cetaceans (CIRCE), It puts the focus on greenhouses that use a lot of plastics, because many of them "end up floating on the coast".
The substances analyzed are added to plastics to increase their hardness, flexibility, give them color ... "There are more than 3,000 different compounds of this type, and at least there are 60 that are harmful to man," he says. Eljarrat emphasizes that when carrying out the study on samples they had all the tissues and organs, something that is not possible when biopsies are carried out in the sea with live specimens, because only the values of the fat can be obtained.
The organophosphorus began to be used in the sixties of the last century. Its use increased four decades later, when the Stockholm Convention of 2009 banned other products because of its toxicity. "Despite being less harmful than its predecessors, there are studies that show that they can cause neurological damage, endocrine disruption, cancer and fertility problems," the CSIC explains in a statement.
The highest levels have appeared in fat and the lowest in the liver. Of the 12 controlled products, seven had reached the brain through the blood-brain membrane. "This worries us because some have the potential to cause neurological damage," explains the scientist. All mammals have that membrane that prevents toxic substances from reaching the brain, but there are compounds that cross it and their dangerous effects are demonstrated. "In this way, the researchers ask if something similar could happen in man. The two routes of entry into the body in this case would be diet, eating contaminated fish, or inhaling in indoor spaces such as houses or offices. "They are places where we are surrounded by plastic and organophosphate levels are quite high", describes .
"It's not a problem of the Alboran Sea, it's globally," says Eljarrat. The results of other studies of the CSIC in dolphins of the Catalan coast and in the Indian Ocean give similar results. "In the Indian Ocean, one of the most polluted in the world, the levels are between 10 and 100 times more," he stresses.