Native South Americans far more likely to die from smoke from wildfires, study finds
Indigenous peoples in the Amazon Basin are twice as likely to die prematurely from smoke exposure from wildfires than the general South American population, a new study finds. Regions of Peru, Bolivia and Brazil are identified as particular hotspots for smoke exposure, with death rates up to six times that of the general population.
The study – authored by researchers from Harvard University, Columbia Climate School Lamont-Doherty Earth Observatoryand other establishments — just published in the review Environmental Research: Health.
Research shows that smoke from wildfires in South America caused around 12,000 premature deaths each year from 2014 to 2019, with around 230 deaths occurring in indigenous territories. Exposure to smoke accounted for 2 premature deaths per 100,000 in the general population, but 4 per 100,000 in indigenous territories. In indigenous regions of 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 Amazon dry season, from August to November, when forest fires more than double concentrations of fine particles, which can be inhaled with deadly consequences.

Farmers in a still smoldering landscape where a cooking fire has escaped into the surrounding scrubland near Pucallpa in the Peruvian Amazon. Such fires pose a serious health threat, especially to nearby indigenous peoples. (Kevin Krajick/Earth Institute)
“While indigenous territories account for relatively few fires in the Amazon Basin, our research shows that people living in these territories are exposed to significantly greater health risks from smoke particles,” said Eimy Bonilla. of Harvard, lead author of the study.
Past research in the field has tended to focus on just one or two seasons, or have relied heavily on hospital admission data. The researchers say this research does not accurately reflect the impacts on people living in indigenous territories, who are often located near fires and lack access to medical care. Instead, the new study uses a combination of atmospheric chemical transport models and other data to estimate the premature mortality rate of indigenous populations exposed to high concentrations of particulate matter.
Over the past decade, the rate of biomass burning in South America has increased, driven by agricultural land clearance, mining and logging. Dry seasons have extended in recent decades and droughts have become more frequent, creating conditions conducive to the spread of fires.
Fires release tiny smoke particles called PM2.5, which are known to have a significant impact on human health. Exposure to particles can lead to cardiovascular and respiratory diseases, cancers, premature births, metabolic dysfunctions and other problems. Particles can travel great distances, affecting air quality in several countries.
“We suggest that governments respond to this with a multi-pronged approach,” said the study’s co-author. Garima Raheja, a Ph.D. candidate for Lamont-Doherty. “Creating infrastructure for Indigenous communities to install air pollution sensors is an essential first step. Regulating deforestation in the Amazon would mitigate the number and size of forest fires that cause this pollution. The authors also argued for indigenous communities to benefit from greater environmental governance on their own lands.
Adapted from a press release by Environmental research: Health.