Air pollution may be a leading cause for antibiotic resistance globally, new study finds

A new study is linking air pollution to the global amount of antibiotic resistance, when medicines used to treat bacterial infections become less effective.

Scientists found a connection between the two after analyzing data from over 116 countries over nearly two decades and shared their findings Monday in the journal The Lancet Planetary Health. In the model created by the researchers, air pollution was found to be responsible for 11% of changes in average antibiotic resistance levels globally, possibly making particle pollution a leading driver.

“Antibiotic resistance and air pollution are each in their own right among the greatest threats to global health,” wrote the study's lead author Hong Chen.

However, the study, which examined nine bacterial pathogens and 43 types of antibiotics, is observational and can't prove a connection or explain what the connection would be.

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Antibiotic resistance is considered to be one of the most harmful threats to global health as infections like pneumonia and tuberculosis are becoming harder to treat, the World Health Organization (WHO) states.

Chen and the other researchers created a model to view antibiotic resistance levels and air pollution levels called PM2.5. The researchers found that particle pollution rose with the levels of antibiotic resistance.

What is particle pollution and antibiotic resistance?

The US Environmental Protection Agency defines PM2.5, also called particle pollution or particulate matter pollution, as the combination of solid and liquid droplets found in the air. Coal, cars, unpaved roads, construction sites, natural gas-fired plants and wildfires can create particulate pollution. Dirt, dust, soot and smoke are forms of particulate pollution.

WHO defines antibiotic resistance, also called antimicrobial resistance or AMR, as what happens when a particular pathogen like a bacteria, fungi or parasite - is less affected by medicine, making battling infections difficult.

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The study's authors said air pollution needs to be considered a significant cause of antibiotic resistance just like other activities scientists have found including poor sanitation, poor infection control in hospitals, the misuse of antibiotics and the overuse in farm animals. The study suggests every 1% increase in air pollution can be linked to a rise in antibiotic resistance between 0.5 and 1.9%, based on the pathogen.

While the possible connection needs to be further studied, the researchers said if their model's analysis is accurate and consistent, then the level of antibiotic resistance around the world could be 17% higher by 2050, meaning around 840,000 people could die due to ineffective antibiotics.

Antimicrobial-resistant cases and deaths in the US

In 2019, the last year for which data is available, more than 2.8 million Americans had antimicrobial-resistant infections and more than 35,000 died, according to the CDC. Worldwide, deaths already top 5 million a year and are expected to grow into the tens of millions within a few decades.

"We are truly right now in the midst of this crisis," Brenda Wilson, a professor of microbiology at the University of Illinois said in a recent American Society for Microbiology talk.

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The U.S. was making solid progress against antibiotic resistance before the coronavirus pandemic. Thanks to improved infection prevention and control and better stewardship, deaths from antimicrobial resistance declined by 18% overall and 30% in hospitals from 2012 to 2017.

But the pandemic pushed hospitals and other health care facilities near their breaking point in 2020, leading to an increase in antibiotic use, trouble following infection prevention and a significant increase in resistant infections in U.S. hospitals, the CDC found. Resistant hospital-onset infections and deaths increased at least 15% that year, although data outside hospitals is lacking.

Contributing: Karen Weintraub and Adrianna Rodriguez