Increase in antibiotic resistance may be linked to rising air pollution, says Lancet study

The authors created an extensive dataset to explore whether PM2.5 is a key factor driving global antibiotic resistance, using data from 116 countries from 2000 to 2018. In total, data on more than 11.5 million test isolates were included in the analysis, covering nine bacterial pathogens and 43 types of antibiotics. Data on antibiotic usage, sanitation services, economics, health spend, population, education, climate, and air pollution was used to investigate the influence of these factors on levels of antibiotic resistance. Data sources included surveillance databases, the World Health Organization, European Environment Agency, and the World Bank.

Antibiotic resistance is a severe global issue, causing approximately 1.27 million premature deaths in 2019 worldwide, substantially exceeding the estimated 0.70 million deaths in 2016.

“Although air is recognized as being a direct pathway and key vector for disseminating antibiotic resistance, there is limited quantitative data on the different pathways that antibiotic-resistant genes are carried via air pollution. Some potential pathways include hospitals, farms, and sewage-treatment facilities that emit and spread antibiotic-resistant particles through the air and across distances,” lead author professor Hong Chen, of Zhejiang University, China, said.

Hong Chen added that until now, there was no clear picture of the possible links between the two, but this work suggests the benefits of controlling air pollution could be two-fold: not only will it reduce the harmful effects of poor air quality, it could also play a major role in combating the rise and spread of antibiotic-resistant bacteria.

The findings indicate antibiotic resistance increases with PM2.5, with every 1% rise in air pollution linked with increases in antibiotic resistance of between 0.5 and 1.9%, depending on the pathogen. The association has strengthened over time, with changes in PM2.5 levels leading to larger increases in antibiotic resistance in more recent years.

The analysis indicates antibiotic resistance resulting from air pollution is linked to an estimated 480,000 premature deaths in 2018. This led to additional economic costs of $395 billion.

“The new observation is that air pollution is one more method by which microbial resistance is spreading. Researchers have found that the exhaust emissions from the hospital buildings contain aerosols loaded with bacteria and antibiotic resistance genes,” Dr Rajeev Jayadevan, a member of the public health advisory panel of the Indian Medical Association, Kerala, who was not involved with the study, told The Indian Express.

“Now these tiny invisible particles -PM-2.5 that are suspended in air- worse during times of air pollution, could carry such bacteria or the antibiotic resistance genes over long distances,” he added.

Dr Jayadevan said it was true that both air pollution and the presence of bacteria/antibiotics in the environment are often seen in urban areas which are overcrowded, have more hospitals, with poor overall sanitation and illegal dumping of waste- where such organisms and antibiotics can easily contaminate the environment.

“Hence more research is needed to confirm the authors’ hypothesis that when suspended air particles are breathed into the lungs of individuals or deposited in the environment, these genes could enter the bacteria that are already living here, making them resistant. This is a certainly plausible hypothesis and makes for a strong case for controlling air pollution,” Dr Jayadevan said.

Dr Renu Bharadwaj, former head of the Department of Microbiology, B J Government Medical College, said antibiotic resistance has become the biggest problem in the management of infections.

“We may soon be reaching the pre-antibiotic era and have no antibiotics in our hands to treat serious infections,” said Dr Bharadwaj adding that this was caused due to the misuse of antibiotics in veterinary and clinical practice, resulting in the dissemination of antibiotic-resistant genes in our environment.

“Such genes coming in contact with a sensitive bacteria is likely to make it resistant to commonly used antibiotics. So while controlling air pollution is important, there is a need for strict control on the use of antibiotics,” Dr Bharadwaj added.

According to study researchers, if no actions are taken, this negative effect on health caused by increasing air pollution and antibiotic resistance is expected to escalate, especially with the global population approaching 9.7 billion by 2050.

North Africa and West Asia are the regions with the most severe PM2.5 levels. Policies in PM2.5 control in these regions might lead to substantial changes in antibiotic resistance, as suggested by the finding that deaths attributable to antibiotic resistance could be reduced in 2050 in the scenario in which the 5 µg/m³ PM2.5 target set by WHO is met.