Increased antibiotic resistance has been linked to air pollution

Chinese scientists analyzed 19 years of data from 116 countries and found that air pollution with particulate matter as small as 2.5 micrometers (PM2.5) was statistically significantly associated with pathogen resistance to antibacterial drugs. As reported in The Lancet Planetary Health, this correlation increased over time and is associated with nearly half a million excess deaths.

Antibiotic resistance is considered a major global health problem. In 2019, it was responsible for approximately 1.27 million premature deaths worldwide. And, while the irrational use of antibiotics acts as a major cause of resistance, there is evidence that air is a key "vector" for antibiotic resistance.

For example, PM2.5, a major air pollutant, has been shown to contain a variety of antibiotic-resistant bacteria and antibiotic resistance genes that are transferred between environments and directly inhaled by humans, causing respiratory damage and infection. In addition, PM2.5 particles can increase the permeability of cell membranes, which enhances the efficiency of horizontal gene transfer, accelerating the evolution and exchange of antibiotic resistance elements in bacterial pathogens. However, there are no global quantitative estimates of this impact.

Baojing Gu and Hong Chen and colleagues from Zhejiang University analyzed air pollution and antibiotic resistance data from 116 countries from 2000 to 2018. The final dataset included more than 11.5 million isolates, which included antibiotic resistance data for nine pathogens (Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas coli, Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Enterobacter aerogenes, Enterococcus faecalis and Enterococcus faecium) and 43 antibiotics.

Researchers found significant continuous correlations between PM2.5 and antibiotic resistance worldwide for most antibiotic-resistant bacteria (R2 = 0.42-0.76, p < 0.0001), and the correlations increased over time. High levels of antibiotic resistance were found in North Africa, the Middle East, and South Asia, while antibiotic resistance levels were low in Europe and North America. Weighted linear regression analysis confirmed the statistical strength of the correlation. A mean increase in PM2.5 concentration of one microgram per cubic meter of air was associated with a 0.48 percent increase in antibiotic resistance.

Air pollution was found to be a major factor in antibiotic resistance, accounting for 10.9 percent of the change in cumulative resistance. It was followed by water pollution and irrational use of antibiotics. Antibiotic resistance due to PM2.5 caused an estimated 0.48 million premature deaths in 2018, representing an annual economic loss of $395 billion.

In a model in which no air pollution reduction measures were applied, antibiotic resistance increased by 17 percent globally by 2050, and annual antibiotic resistance-related deaths increased by 56.4 percent (largely driven by sub-Saharan Africa). With full-scale policies to reduce air pollution, reducing PM2.5 concentrations by every five micrograms per cubic meter of air would reduce global antibiotic resistance by 16.8 percent and reduce excess mortality by about 23.4 percent by 2050.

According to the scientists, this first strong evidence of the global impact of air pollution on the development of antibiotic resistance will help in the development of environmental policies in different countries to control air pollution.

Air pollution has a direct negative impact on human health. For example, high concentrations of nitrogen dioxide in inhaled air led to lower systolic blood pressure in London adolescents. At the same time, PM2.5 increased it.