Microplastics are found in the blood of animals even in remote areas of the Pantanal

The researchers analyzed blood samples from 26 tapirs and 21 giant anteaters, collected in the Amazon, Cerrado and Pantanal between 2021 and 2022. The particles appeared in 43 of the 47 animals.

According to the study, the average concentration was 73.8 particles per milliliter of blood, but the values ​​varied greatly between individuals.

Tapirs presented, on average, higher concentrations than anteaters, although the difference between species was not considered statistically significant.

Microplastics are plastic particles smaller than 5 millimeters. Because they are very small, they can spread throughout the environment through the air, rain, rivers, groundwater and floods.

The study combined blood analyzes with GPS data that showed where each animal moved.

From this, the researchers found a pattern: the greater the presence of human activities in the territory occupied by animals, the greater the amount of microplastics in the blood tended to be.

Higher concentrations were also recorded among animals that lived closer to built-up areas and waste treatment or storage facilities.

“This allowed us to see that the greater the human intervention, the more plastic the animal carries”, explained Marcia de Almeida Monteiro Melo Ferraz, one of the study's authors and researcher at the University of British Columbia, in Canada, to g1.

According to her, one of the results that attracted the most attention was finding the same pattern in animals with very different eating habits.

“Tairs eat plants, anteaters eat ants and termites and also swallow a lot of soil in the process”, he explains. “This suggests that diet is not the only factor behind microplastic exposure.”

The most surprising result, however, appeared in the Pantanal.

All animals analyzed in the region showed microplastics in their blood, including individuals who lived more than 65 kilometers from built-up areas and more than 112 kilometers from a waste facility.

For Ferraz, the result shows that the influence of plastic pollution can go far beyond places directly modified by man.

It is still not possible to say, however, exactly how these particles reached the animals' bodies.

They may have been ingested through water or food or even inhaled, but the study analyzed the plastic present in the blood and did not directly measure its concentration in the environment.

“It could be through food, water or air, but our study measured plastic in the blood, not in the environment, so we can’t say for sure,” says Ferraz.

The types of plastic found also varied between the locations studied.

In the Cerrado, where the area analyzed is marked by agriculture, materials such as PVC and polystyrene appeared in greater proportions, used, among other applications, in pipes, machines and packaging.

In the studied area of ​​the Amazon, polyamide was most common, used in fishing nets and ropes.

In the Pantanal, more polytetrafluoroethylene, known as Teflon, and polypropylene appeared.

The researchers, however, emphasize that these differences do not allow them to directly pinpoint the origin of the particles.

The three sites had different sample sizes and were analyzed as case studies rather than a complete portrait of each biome.

The work also did not assess whether the amount of microplastics found caused harm to the animals' health.

According to Ferraz, there is still no reference value that indicates that a certain concentration is safe or dangerous for wild animals.

Laboratory studies indicate that small particles can cross membranes and accumulate in tissues, but it is not yet known whether the same effects occur under conditions found in nature.

The researcher also avoids stating that the results prove that microplastics are already widespread throughout Brazilian fauna.

Still, she considers that finding particles in different species and in three regions of the country, including the Pantanal, represents “a strong indication” that the contamination may be quite widespread.

“To confirm, we need to study more species and more regions”, he says.

The authors also state that the result also has implications for conservation, because it shows that protecting just an animal's immediate habitat may not be enough to prevent exposure to certain pollutants.

In the study, animals that lived in less altered areas had lower amounts of microplastics than those closer to human infrastructure.

Therefore, researchers argue that improving waste management and considering the location of landfills and other facilities close to wildlife areas can help reduce this exposure.

“There is also a diffusion of these pollutants: plastic reaches animals even when the habitat is relatively preserved, and this also needs to be considered in conservation strategies”, says Ferraz.

According to her, future research should try to answer two central questions: where exactly do these microplastics come from and what effects they can have on the health of wild animals that live free in nature.