Why is plastic contamination so dangerous? The other side of the coin.

By Pedro Campoy López and Alexandre Martínez Schönemann.

The amount of plastic that reaches the marine environment has not stopped increasing and this fact is not new; from the 1950s until now plastic production has grown exponentially, reaching 322 million tons per year currently¹ and collaterally we find the increase of plastic discharges in the sea that is estimated at 4 and 12 million tons per year².

On the left Pedro Campoy López, on the right Alexandre M. Schönemann, both immortalized during their work with endocrine disruptors.

These data have been highlighted, including in the press, with great echo of the images of birds or marine mammals with plastics inside. But despite the hardness of these images, the problem of plastics does not end and is not start as well. A much less known fact is that various types of widely used plastics (such as PET, PVC, PDB, among others) have been added inside a lot of chemical products for stability, elasticity, color, or function as flame retardants, among other properties. And these compounds, along with plastics, in the sea, dissociate from the polymer and generate negative effects in the communities of marine organisms. This fact has important repercussions for a large number of marine organisms, and even for the human being, but has not been remarked by any newspaper.

One of the biggest concerns regarding plastic additives is their hormone-like behaviour and, therefore, to cause an alteration called endocrine disruption in exposed marine organisms, placed in their natural environment. According to the WHO (World Health Organization), endocrine disruptors are defined as: "exogenous compounds, or mixtures of these ones, that alter the functions of the endocrine system and consequently cause adverse effects on the health of organisms, their progeny or populations". This substances have an important effect in the human and animal metabolic systems, altering the growth and the reproduction.

At this point, it is exactly where the ECOTOX research team is focusing its efforts promoting, among other works, two PhD theses based on the use of different experimentation models: an invertebrate of the family of echinoderms, the sea urchin Paracentrotus lividus and an estuarine fish of the cyprinid family, Cyprinodon variegatus, with the aim of observing the harmful effects of these compounds.  This will shed light on whether exposure to a xenoestrogen, such as some plastic additives -bisphenol A, phthalates, flame retardants, UV filters, etc.- may be recognized in the body as a hormone and may lead to the deregulation of growth and reproduction.

In addition, the works, leaded by Dr. Ricardo Beiras, focus on the use of new tools based on the omics techniques (transcriptomics and proteomics) for the search of biomarkers of endocrine disruption, such as target genes and proteins, related to development and sexual maturation of these species.

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1. Ricardo Beiras. Marine Pollution 1st Edition. Elsevier. 2018. p. 69-82 . 
2. Jambeck, J. R., Geyer, R., Wilcox, C., Siegler, T. R., Perryman, M., Andrady, A., ... & Law, K. L. (2015). Plastic waste inputs from land into the ocean. Science, 347(6223), 768-771.