An intense season of fires in the Amazon rainforest this year could overwhelm health systems and lead to unnecessary deaths, including of coronavirus, as pollution worsens respiratory conditions, public health experts said on Wednesday.

Forest fires destroy many thousands of hectares of Amazon rainforest across Latin America each year. As peak burning season approaches, experts say intense fires and the particles they give off could exacerbate coronavirus infections.

“It’s well established that chronic exposure to these small particulates increases the risk of respiratory disease, cardiovascular disease and premature death,” former president of the U.S. Institute of Medicine Harvey Fineberg told journalists in a virtual press conference.

Coronavirus infections in Latin America exceed 1.7 million and more than 83,500 people have died in the region, according to a Reuters tally.

Manaus, a city of 2 million people in the heart of Brazil’s Amazon, has already been hit hard by the virus, with mass burials needed to keep up with soaring deaths.

Across the border, Colombia’s Amazonas province has also struggled under high rates of coronavirus infections. The region has a population of around just 66,000 and has reported over 2,100 cases.

Fears over the effects caused by pollution during the coronavirus pandemic have also been heard in Chile, with experts warning of a “perfect storm” as an expected cold winter causes people to burn more wood, especially in the country’s south.

An increase in hospitalizations for respiratory diseases following forest fires would place additional strain on hospitals that are already struggling under coronavirus, said Harvard University public health professor Marcia Castro.

As well as affecting communities in the Amazon, smoke particles can travel and cause issues elsewhere, Castro said.

“Effects on respiratory conditions are not limited to the Amazon borders,” Castro said. “An intense fire season could have devastating public health consequences with the unnecessary loss of many lives.”

Reuters