Indigenous South Americans Far More Likely to Die From Wildfire Smoke, Study Says

Smoke from wildfires is a health threat to everyone, but Indigenous people in South America are especially vulnerable due to a number of factors.

Columbia Climate School
May 04, 2023

A new study reveals that Indigenous people in the Amazon Basin are twice as likely to die prematurely from smoke exposure due to wildfires than the broader South American population. Regions in Peru, Bolivia and Brazil are identified as particular hotspots for smoke exposure, with mortality rates rising to as high as six times that of the general population.

The study — authored by researchers at Harvard University, the Columbia Climate School’s Lamont-Doherty Earth Observatory, and other institutions — was just published in the journal Environmental Research: Health.

The research shows that smoke from wildfires in South America accounted for approximately 12,000 premature deaths every year from 2014 to 2019, with about 230 of those deaths occurring in Indigenous territories. Smoke exposure accounted for 2 premature deaths per 100,000 in the general population, but 4 per 100,000 in Indigenous territories. In Indigenous areas in Bolivia and Brazil, the rates were 9 and 12 per 100,000, respectively.

Exposure to harmful smoke particles is found to be much higher during the Amazonian dry season, from August to November, when wildfires more than double concentrations of fine-particulate matter, which can be inhaled with deadly consequences.

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Farmers in a still-smoking landscape where a cooking fire escaped into surrounding scrubland near Pucallpa, in the Peruvian Amazon. Such blazes are a serious health threat, especially to nearby Indigenous people. (Kevin Krajick/Earth Institute)

“While Indigenous territories account for relatively few fires in the Amazon Basin, our research shows that the people living in these territories experience significantly greater health risks from smoke particles,” said Eimy Bonilla of Harvard, lead author of the study.

Previous research in the field has tended to focus on just one or two seasons, or has relied heavily on hospital admission data. The researchers say such research does not accurately reflect the impacts on people living in Indigenous territories, who are often located close to fires, and lack access to medical care. The new study instead uses a combination of atmospheric chemical transport models and other data to estimate the rate of premature mortality for Indigenous populations exposed to high particulate concentrations.

In the past decade, the rate of biomass burning in South America has surged, driven by agricultural land clearing, mining and logging. Dry seasons have been expanding in recent decades, and droughts have become more common, providing conditions for fires to spread.

Fires release tiny smoke particles called PM2.5, which are known to significantly impact human health. Exposure to particles can result in cardiovascular and respiratory diseases, cancer, premature births, metabolic dysfunction and other problems. Particles can travel great distances, affecting air quality across multiple countries.

“We suggest that governments respond to this through a multi-fold approach,” said study coauthor Garima Raheja, a PhD. candidate at Lamont-Doherty. “Creating infrastructure for Indigenous communities to set up air pollution sensors is a vital first step. Regulating deforestation in the Amazon would mitigate the number and size of the wildfires that cause this pollution.” The authors also advocated for Indigenous communities to receive greater environmental governance over their own lands.

Adapted from a press release by Environmental Research: Health.