The Alboran Sea is one of the richest biodiversity hotspots in the Mediterranean Sea, but at the same time it is one of the busiest maritime routes.
Now, a study led by the Higher Council for Scientific Research (CSIC) and carried out on dolphins in the Alboran Sea, has revealed the accumulation of organophosphate compounds in the tissues of these marine mammals. The data is more than worrying, since experts have found these plasticizers in fats, muscles, liver and brain of 100% of dolphins analyzed in the Alboran Sea, compounds that could cause neurological damage, cancer, fertility problems and endocrine disruption to these aquatic mammals.
Compounds found in dolphins are used as flame retardants and plasticizers and have been found in concentrations of up to 25 micrograms per gram of fat. According to the scientists, these are levels similar to those collected for other pollutants already legislated, such as plorichlorinated biphenyls (PCBs) or polybrominated diphenyl ethers (PBDEs).
The highest level of concentration of plasticizers has been recorded in fat and the lowest, in the liver. Of the 12 compounds detected in fat, 7 of them were also present in brain samples, indicating their ability to cross the blood-brain membrane.
“This worries us since it has been seen that they have a greater tendency to accumulate in the brain than in other tissues. And it is known that some of them, such as trichloroethylphosphate (TCEP) or tributylphosphate (TNBP), have the potential to cause neurological damage “, explains Ethel Eljarrat, CSIC scientist at the Institute for Environmental Diagnosis and Water Studies who leads the work published in the journal Environmental Research.
” The presence of these pollutants thus adds to the long list of threats posed by this subpopulation of common dolphin of the Mediterranean Sea or, among which are overfishing and environmental changes”, highlights the researcher of the Institute of Marine Sciences Joan Giménez .
To do this work, the scientists compared the amount of organophosphate compounds with those of another family of compounds, halogenated ones, which are also used as flame retardants. “If we take into account that the former account for 15% of the global production of flame retardants and the latter around 30%, the environmental impact of the latter should be higher,” says Eljarrat. “In addition, halogenates have a greater potential for bioaccumulation and biomagnification along the trophic chain.”
However, after analyzing and comparing the results, the experts observed that the levels were similar for both families of pollutants.
Organophosphate compounds are also used as plasticizers
Unfortunately, the Mediterranean Sea is considered an important accumulation zone for floating plastic debris. According to estimates, we can find about 423 grams of plastic per square kilometer.
” If we focus on the Alboran Sea area, we must take into account the impact of greenhouse cultivation, which uses a large amount of plastic materials, many of which end up floating on the marine coast”, explains Renaud de Stephanis, from the association Conservation, Research and Study on Cetaceans.
Plasticizers
Organophosphate plasticizers were used for the first time in the 1960s. Their use increased four decades later, as they were proposed as an alternative to polybrominated diphenyl ethers, other flame retardants that were banned by the Stockholm Convention in 2009 due to their toxicity. While they are less toxic than their predecessors, there are studies showing that organophosphate compounds can cause a great deal of damage, including neurological damage or cancer.
The work is, according to the researchers, the first to identify the accumulation of these compounds used as plasticizers and flame retardants in dolphins.
Referencia: First determination of high levels of organophosphorus flame retardants and plasticizers in dolphins from Southern European waters. B.Sala, J.Giménez, R.de Stephanis, D.Barceló, E.Eljarrat. Environmental Research. DOI: https://doi.org/10.1016/j.envres.2019.02.027
Crédito imagen: CIRCE
