Microplastics found in the blood of tapirs and anteaters in Brazil

TL;DR in 30 sec

• Scientists found microplastics in the blood of 43 of 47 wild tapirs and giant anteaters in Brazil, according to a study in Nature reported by Phys.org and dpa.
• Animals living closer to people and to waste disposal sites had more microplastics in their blood, Phys.org reported.
• In the Pantanal wetlands, every animal tested carried microplastics, including some living more than 65 km from the nearest settlement, dpa reported.
• The study did not measure whether the particles harm the animals, Phys.org reported.

What happened

An international team tested blood from 26 lowland tapirs and 21 giant anteaters, Phys.org reported. The paper, “Human land use drives microplastic abundance in terrestrial wildlife”, was published in Nature on 11 November.

The blood samples were taken between February 2021 and November 2022, according to dpa and blue News. They came from three regions: a deforested area on the southern edge of the Amazon, the Cerrado savannah and the Pantanal wetlands, dpa reported.

Using GPS tracking, the researchers mapped where each animal moved and how close it came to human activity and infrastructure, Phys.org said. They then compared each animal’s home range, the area it usually roams, with the microplastic levels in its blood.

Levels were significantly higher in animals whose home ranges included more human disturbance. They were also higher in animals living closer to waste management facilities, according to Phys.org.

The lead author is Marcia de Almeida Monteiro Melo Ferraz of the University of British Columbia in Kelowna, Canada, Phys.org reported. Co-author Justin Calabrese works at the Helmholtz-Zentrum Dresden-Rossendorf in Germany.

Why it matters for India 🇮🇳

The authors say better waste management around human settlements could greatly reduce microplastic levels in wildlife, and that this matters especially in rapidly developing countries like Brazil, Phys.org reported. They also suggest buffer zones around nature reserves.

Indian researchers have looked for microplastics in wild animals too. A study in the journal Environmental Research found microplastics in every scat (droppings) sample collected from jungle cats and fishing cats in the Indian Sundarbans, Mongabay India reported.

The samples were collected between February and July 2023. Fibres made up over 70% of the particles found, according to Mongabay India.

That study looked at scat, not blood or tissue, Mongabay India noted. The sources do not report any study of microplastics in the blood of wild mammals in India.

Background

Microplastics, tiny pieces of plastic, have been found in farmland soils, on mountain peaks, in remote forests, on glaciers and in river floodplains, dpa reported.

Rivers can carry plastic into floodplains, and plastic sheeting and contaminated compost can bring it onto farmland, according to dpa. The new study says particles can also reach remote areas through the air and water, dpa and blue News reported.

The animals in the Pantanal lived more than 65 km from the nearest settlement and more than 112 km from the nearest waste disposal site, dpa reported. Their blood concentrations were substantially lower, and their GPS data showed no direct exposure to human-modified land, according to Phys.org.

Different perspectives

The reports agree on the main findings, and they are careful to say what the study does not show.

Microplastics are “demonstrably hazardous to many species under experimental conditions”, Phys.org reported, but the study did not measure health effects in these animals. The effects of micro- and nanoparticles on ecosystems and human health “have not yet been conclusively established”, dpa reported.

In the Indian study, co-author Arunava Mukherjee cautioned against panic, Mongabay India reported. He said build-up of microplastics through the gut is not yet well established in higher mammals.

No comment from scientists outside the study team was found in the sources.

Open questions 🤔

• Do the plastic particles in their blood harm tapirs and anteaters?
• Do wild mammals in India also carry microplastics in their blood?
• How do microplastics reach animals that live far from people, by air, by water or through their food?

What to watch next

No follow-up study or official response has been announced in the sources.