Microplastics turned up in the blood of 43 of 47 wild tapirs and anteaters in Brazil, including animals living 40 miles from any town
Animals living closer to development and garbage sites carried more plastic, a study in Nature finds, suggesting better waste handling could lower the load.
Microplastics were found in the blood of 43 of 47 wild lowland tapirs and giant anteaters tested in Brazil, and animals that lived closer to roads, towns and waste facilities carried more of them, according to a study published Nov. 11 in the journal Nature. The authors say managing waste near settlements and keeping development away from wildlife habitat could reduce how much plastic wild animals absorb.
Even animals in Brazil’s Pantanal, the world’s largest wetland and one of its least disturbed, had microplastics in their blood, at lower levels. Every animal sampled there carried some, although they lived more than 65 kilometers (about 40 miles) from the nearest development and more than 112 kilometers (about 70 miles) from the nearest waste facility. That suggests the particles travel far, likely by air and water, the researchers wrote.
What the researchers found
- Blood held an average of 73.8 plastic particles per milliliter, with a wide range from none to 1,211 per milliliter.
- Tapirs averaged 98.9 particles per milliliter and giant anteaters 42.8, a difference too small to be certain.
- Plastic levels rose the closer an animal’s home range was to development and to waste management facilities, and with the most intense human disturbance inside its range.
What this means
Plastic pollution is not only an ocean problem. Large land animals are carrying it in their blood, and the closer they live to people and garbage, the more they carry. The average level in the animals, 73.8 particles per milliliter, falls within the range other studies have reported in human blood, 1.9 to 108 particles per milliliter, the authors wrote. Whether those levels hurt animals or people is still unknown.
The problem is likely to grow. Brazil’s human footprint, a measure of roads, farms, towns and other development, rose 42% from 2001 to 2020, and garbage collection and sewage treatment are limited across much of rural Brazil, the paper says. The authors expect plastic levels in wildlife to keep climbing as development spreads.
There is also a practical lesson. Animals in less disturbed places carried much less plastic, so better waste handling near towns and keeping development and dumps away from wildlife habitat could cut what animals absorb, the authors wrote. Their method of pairing blood tests with GPS tracking can be used for other species and places to find the animals most at risk.
How the study worked
Microplastics are plastic bits smaller than 5 millimeters, about a fifth of an inch. From 2021 to 2022, researchers led by Marcia de Almeida Monteiro Melo Ferraz of the University of British Columbia Okanagan in Canada took blood from 26 tapirs and 21 anteaters in the Amazon, the Cerrado grasslands and the Pantanal, and tracked their movements with GPS collars. They identified particles larger than 1 micrometer with a laser method called Raman spectroscopy and compared each animal’s levels with how much human activity it lived near. The study did not measure whether the plastic harmed the animals.