Mussels can be a gateway for microplastics into the human body, suggests a scientific study by the Federal University of the State of Rio de Janeiro (Unirio) published this Monday (15). These molluscs live on rocky shores at the seashore and are enjoyed in various recipes in Brazilian cuisine. Contamination occurs because these beings, which are part of the human diet, feed by filtering water and are unable to distinguish microalgae ─ their natural foods ─ from microplastics, elements that pollute seas and rivers. Related news: Researchers propose strategies to combat microplastics in the country. World Bee Day: microplastics and urban lighting are threats. Study finds microplastic in 93% of fish samples on the coast of PR. The Unirio study was published by the scientific journal Ocean and Coastal Research. Despite being in a foreign language, Ocean and Coastal Research is a Brazilian journal edited by the Oceanographic Institute of the University of São Paulo (USP). The disclosure was made in partnership with Agência Bori, focused on scientific studies. Collection at the beach To reach their conclusions, the researchers collected at Praia Vermelha, in the south zone of Rio de Janeiro, the brown mussel species (Perna Perna), which is very popular in cooking. The shellfish were taken to a university laboratory, where environmental conditions were simulated. To evaluate how the mussels would filter water and feed on microalgae and microplastics, they were divided into three groups. The groups were offered three solution options in the water: microalgae only; only microplastics; and mixed with microalgae and microplastic. The team analyzed the water in the aquariums after an hour and found that the mussels consumed the materials indiscriminately, as marine biologist and professor Raquel de Almeida Ferrando Neves, one of the study's co-authors, explained to Agência Brasil. "We were able to identify that they have no perception, they cannot differentiate between natural particles and plastic particles." In the tank containing the mixture, the mussels left around 48% of the microalgae and 52% of the plastic spheres. For researchers, similar rates prove the lack of selectivity of the species.   Plastic pollution on Botafogo Beach, in Rio de Janeiro - Fernando Frazão/Agência Brasil Microplastic Microplastics are fragments of the larger material, plastic, which, under the influence of time and sunlight, break down into microparticles and end up remaining in the water, soil and air. These particles can be released from trash at sea, such as packaging, bottles, tires, fabrics and paint coatings. Paints, in fact, are sources of chemical elements present in these fragments. At the end of May, Agência Brasil reported that microplastics were found in 93% of a fish sample off the coast of Paraná. Another Brazilian research even found microplastics in placentas and umbilical cords. The World Health Organization recognizes that the world faces problems related to microplastic pollution and advocates for more research into the effect of fragments on human health.   Ecosystem on the Prainha coast, in Arraial do Cabo. Photo: Fernando Frazão/Agência Brasil Contaminants Professor Raquel Neves, from the Department of Ecology and Marine Resources at Unirio, warns that microplastics can have many surface contaminants. “This, for human health, is always very risky and dangerous, because these mussels are filter feeders, and filtering organisms accumulate chemical contaminants”, he details. One of the winners of the 2023 edition of the Prize for Women in Science, granted by the L’Oréal Group, in partnership with the Brazilian Academy of Sciences and the United Nations Educational, Scientific and Cultural Organization (Unesco), the biologist points out that the degree of presence of microplastics in the human body depends on the type of diet. "If a person consumes sporadically, they will have less risk, less exposure. We call this consumption risk analysis. If they consume very frequently, they will be more exposed to this particular contaminant", he states. Neves also points out that, unlike pathogenic microorganisms and gastrointestinal parasites, cooking food is not enough to reduce health risks. In the case of biotoxins, microplastics, metals and chemical contaminants, cooking does not reduce contamination levels in mussels. Standardized behavior The researcher considers that, although the experiment sample was from a specific location in Rio de Janeiro, the finding that mussels confuse microplastics with food applies to other regions. "This species occurs anywhere on the coast. So, normally, there is no difference in behavior. Feeding pattern, filtration rate pattern, this does not usually vary according to the location", he says. “It varies more depending on the availability of food and the availability, in this case, of plastic particles.” Solutions Unirio researchers maintain that, to protect coastal communities and stop cascading contamination, practical actions are needed to cut pollution at its source, such as public policies to reduce the dumping of waste at sea and massively restrict the circulation of single-use plastics. The team also advocates constant scientific monitoring of mariculture areas, where marine organisms are cultivated, as one of the viable ways to ensure that the economy and seafood consumption survive safely in the future.