Reducing air pollution could be a critical step in combating the rising threat of antibiotic-resistant bacteria and save thousands of lives, researchers have found.
The findings, published in The Lancet Planetary Health journal, provide new pathways for controlling antibiotic resistance from an environmental perspective and could bring considerable health and economic benefits worldwide.
The first comprehensive global study to explore the connection between air pollution and antibiotic resistance emphasised that PM2.5 – particles 30 times smaller than a human hair – can also contain the bacteria.
These particles can be inhaled directly by humans, potentially contributing to the spread of antibiotic resistance.
Sources of PM2.5 include industrial activities, road transport and domestic coal and wood burning.
Currently, 7.3 billion people are exposed to unsafe levels of PM2.5, with the majority living in low and middle-income countries.
The lead author of the study, Prof Hong Chen of Zhejiang University in China, stressed the severity of the situation. “Antibiotic resistance and air pollution are each in their own right among the greatest threats to global health,” she said.
“Until now, we didn’t have a clear picture of the possible links between the two but this work suggests the benefits of controlling air pollution could be twofold.”
How pollution contributes to antibiotic resistance
As pollution levels rise, certain harmful bacteria become more resilient to drugs meant to fight them. In regions such as North Africa and the Middle East, this connection between pollution and antibiotic resistance is particularly strong.
A 1 per cent increase in PM2.5 across regions was associated with an increase in Klebsiella pneumoniae's resistance to various antibiotics. Changes in concentration of PM2.5 have led to larger increases in antibiotic resistance since 2013.
The latest research highlights the impact on large populations such as those found in China and India.
The Middle East and North Africa, along with South Asia, exhibited high levels of antibiotic resistance, while Europe and North America showed low rates.
PM2.5 was one of the largest drivers of antibiotic resistance, contributing 10.9 per cent of variation in aggregate resistance. North Africa and West Asia were the regions where PM2.5 had the highest contribution (18.9 per cent) to antibiotic resistance.
Based on the recorded data – but allowing for the affect of misuse/overuse of the antibiotics – it was estimated Saudi Arabia would have a 3 per cent increase in antibiotic resistance resulting from a 10 per cent increase in PM2.5, Niger a 2.9 per cent increase, the UAE a 2.6 per cent increase and Pakistan a 2.6 per cent increase.
Globally, a 10 per cent increase in annual PM2.5 could lead to a 1.1 per cent increase in aggregate antibiotic resistance and 43,654 premature deaths attributable to antibiotic resistance.
Global impact and possible solutions
Through an extensive data set, researchers explored how PM2.5 is a vital factor in global antibiotic resistance, with every 1 per cent rise in air pollution linked with increases in antibiotic resistance of up to 1.9 per cent.
If current policies remain unchanged, the level of antibiotic resistance worldwide could soar by 17 per cent by 2050, with an annual premature death toll rising to about 840,000.
The study advocates policies such as limiting PM2.5 to 5mg per cubic metre in the atmosphere as recommended by the World Health Organisation, which could significantly decrease global antibiotic resistance and lead to substantial economic savings.
While the study represents a landmark in understanding the relationship between air pollution and antibiotic resistance, the authors acknowledge limitations, including lack of data in some countries and differences in relative risks and testing availability.
Future research should focus on uncovering how air pollutants and other factors affect antibiotic resistance and explore possible interactions between elements, the researchers suggest.
They said the novel findings of this study highlight the interconnection between environmental factors and global health. By controlling pollution and adhering to air quality guidelines, the world could make significant strides in reducing antibiotic resistance, saving lives and mitigating economic burdens, it was found.