Wild tapirs and anteaters nearer human development carry more microplastics

Microplastics turned up in the blood of 43 of 47 wild tapirs and giant anteaters sampled in Brazil, averaging 73.8 particles per millilitre, with higher levels in animals living nearer built-up areas and waste sites, an association the study measured but did not prove is causal.

Peer reviewed · Observational field study · 47 animals · No health effects measured

Wild lowland tapirs and giant anteaters in Brazil carry tiny plastic particles in their blood, and the animals whose home ranges sit closer to human development carry more, according to a study published on 11 November 2026 in Nature. Marcia de Almeida Monteiro Melo Ferraz of the University of British Columbia Okanagan and 13 colleagues paired blood tests with GPS tracking. Even animals in the Pantanal wetland, more than 65 km from the nearest development, had particles. The link is an association from 40 tracked animals, and the study did not look at whether the plastic harms them.

Evidence at a glance

Is this a big deal?

A solid step, not a final answer. Finding plastic in wild animals is no longer news; linking the amount in each animal’s blood to the ground it actually walks on is new for land mammals. The sample is small, and the authors present it as a method other teams can repeat.

What scientists found

The team’s software identified 17,165 particles well enough to name their material, and 2,815 of them (16.4%) were plastic. Only four animals, three anteaters and one tapir, had none. The average was 73.8 particles per millilitre, which works out to roughly 370 particles in a teaspoon (5 ml) of blood. The particles were small: on average about 10 micrometres long, or one hundredth of a millimetre. Common types included polyethylene, polypropylene, polystyrene, PET, nylon and PVC.

Tapirs averaged 98.9 particles per ml and anteaters 42.8, a difference that was not statistically significant. The bigger differences ran between individuals.

Animals whose home range contained a higher peak value on the Human Footprint Index, a global map score running from 0 for untouched land to 50 for the most heavily modified, had more plastic in their blood. So did animals living closer to development (towns, mines and power plants) and to waste facilities. The average footprint score across the home range was not a significant predictor. One reading, ours rather than the paper’s, is that the nearest pockets of intense human activity matter more than the general level around an animal.

How they found it

The work depended on catching large, threatened animals alive. Field teams from Brazil’s Instituto de Conservação de Animais Silvestres (ICAS) and the Instituto de Pesquisas Ecológicas (IPÊ) darted or trapped tapirs, and netted giant anteaters spotted from trucks along dirt roads near two federal highways. Each animal was sedated, sampled, fitted with a GPS tracker and released where it was caught.

The three sites span a range of human pressure: a soy farm on the southern Amazon’s arc of deforestation, a Cerrado savanna mixed with farms and highways, and a relatively undisturbed cattle ranch in the Pantanal wetland. More than 450,000 GPS positions, after error filtering, gave each animal’s home range and its distance to development.

In the lab, 1 ml of each sample was dissolved in strong alkali and bleach, filtered, and every remaining particle was hit with a laser. The light a particle scatters back, its Raman spectrum, works like a chemical fingerprint that software matched against libraries of known plastics.

Contamination is the obvious objection, since needles, stoppers and air all shed particles. The team ran one blank per processing batch, drawing filtered water through the same needles and tubes. The blanks held 64.0 and 14.7 particles per ml, mostly silicone and other materials that were not the main plastics in the blood, and those counts were subtracted polymer by polymer.

Why it matters to you

This study won’t change anything about your own health or routine. It measured plastic in animal blood, not in people, and did not test for harm. It does sharpen the picture of where plastic pollution goes: wildlife near built-up areas and waste sites carries more, while some reaches animals far away, which the authors suggest happens through air and water. For places where forests and grasslands are being converted to farms, it points to local waste handling as something worth studying.

What the evidence does not show

It does not show that living near people causes higher plastic levels. The paper’s title says “drives”, but the design can only show that the two go together; animals near development might eat or drink differently in ways the study did not measure.

The statistics are thin in places. With tapirs alone, the footprint link was no longer significant, and the two distance links lost significance when the top 10% of values were dropped. The authors also call their site-by-site comparisons of plastic types case studies, especially for the Pantanal.

It says nothing about harm. The animals’ health was not tested, and a single 1 ml sample cannot show how long particles stay in the body.

How this fits what we already knew

Microplastics, plastic pieces smaller than 5 mm, are carried by air, rain, rivers and groundwater, and the paper notes they have reached even remote habitats. Most land-animal studies, the authors write, were descriptive surveys that recorded whether plastic was there. Comparable blood data for other wild land animals are not yet available, so the closest yardstick is people: the paper notes that its 73.8 particles per ml falls within the 1.9 to 108 particles per ml reported in human blood by spectroscopy-based studies. Methods vary between labs, so that comparison is rough. On human exposure, see our report on plastic particles counted in bottled water.

The study also places its findings against fast change in Brazil. Using a published global dataset, the authors calculate that Brazil’s average Human Footprint Index rose from 4.17 in 2001 to 5.92 in 2020, a 42% increase, against a 26% rise worldwide, from 5.26 to 6.63.

Outside views and the study team’s claims

Co-author Justin Calabrese, who leads a research team specialising in animal movement analysis at the Center for Advanced Systems Understanding (CASUS) in Görlitz, Germany, said in the institute’s release: “Animals moving in more disturbed areas, or in closer proximity to human infrastructure, do indeed tend to have higher microplastic burdens, and our paper is the first to demonstrate this linkage for terrestrial mammals.”

Independent comment is limited so far. Nature News reported that Sofia Ya-Hsuan Liou, a geochemist at National Taiwan University, called the findings an important step toward understanding how the particles affect wildlife. SciQuest has not yet interviewed an outside researcher.

One claim in the coverage deserves care. The CASUS release says the authors conclude that better waste management “could greatly reduce” microplastic levels in wildlife. The paper itself is more cautious, suggesting that managing animals’ proximity to development and waste infrastructure “may reduce” their burdens. No one has yet tested an intervention.

How other headlines framed it

• Nature News led with the remote angle: even giant anteaters in Brazil’s far-flung wetlands have plastic in their blood, at levels similar to many people.
• The dpa report carried by Yahoo News also stressed remote Brazil, adding broader context that plastic now reaches soils, mountains and glaciers, and that its effects on ecosystems and health are not settled.
• Phys.org, reposting the CASUS release, framed it by distance: particles in wild mammals more than 40 miles from human infrastructure.

All three report the core result accurately; none of the short reports mentions how sensitive the distance links are to a few extreme values.

What happens next

The authors say the next step is sampling soil and water alongside blood, to match the plastics in an animal to those around it, a hard task because blood and soil need different lab methods. The data and code are public on GitHub, so other groups can repeat the approach elsewhere.

In one sentence

Tapirs and anteaters that live closer to built-up areas and waste sites tend to carry more plastic in their blood, but even animals tens of kilometres from any development carry some, and nobody yet knows what it does to them.

Read next

• How many plastic particles are in bottled water?
• What lives in the Mariana Trench, including a crustacean named after plastic

Sources and disclosure

1. Ferraz, M. A. M. M., Desbiez, A. L. J., Alves, M. H., Calabrese, J. M. et al. Human land use drives microplastic abundance in terrestrial wildlife. Nature (2026), published 11 November 2026; received 9 July 2025, accepted 9 October 2026. Includes Extended Data and Supplementary Information.
2. Center for Advanced Systems Understanding (CASUS), Helmholtz-Zentrum Dresden-Rossendorf. Microplastics and wildlife: study links animal burden and human footprint, 11 November 2026.
3. Conroy, G. Even giant anteaters in remote Brazil have microplastics in their blood. Nature News, 11 November 2026.
4. Study data and code: figshare archive and GitHub repository.

The authors declare no competing interests. Funding came from Canadian, German and Brazilian research and conservation bodies, as listed in the paper.

Disclosure: This article was drafted with AI assistance and checked against the sources above. The teaspoon conversion and the trend curve in the graphic are SciQuest calculations from figures reported in the paper. Spotted an error? See our corrections policy.