As air pollution indexes across the globe are on the rise, researchers have identified a new detrimental consequence of air pollution which is growing resistance against antibotics.
According to a detailed global analysis published in The Lancet Planetary Health, the increased dissemination of antibiotic resistance genes (ARGs) particularly via airborne fine particles (PM 2.5), are widely responsible for causing the highest levels of antibiotic resistance and premature death in population-dense countries includng India and China. The list also included few other nations in South Asia, North Africa and the Middle East. According to the report, the analysis indicates antibiotic resistance resulting from air pollution is linked to an estimated 480,000 premature deaths in 2018.
After following meticulous methodologies, the findings have explicitly highlighted the quantum of antibiotic resistance. According to the report, with every one per cent rise in PM 2.5 pollution, there is an increase in antibiotic resistance between 0.5 and 1.9 per cent, depending on the pathogen.
The reasearchers are afraid that no action would simply exacerbate the negative effect on health caused by increasing air pollution and antibiotic resistance, considering the fact that the global population ia on the verge of reaching 9.7 billion by 2050.
Before delving into the nexus between PM 2.5 and antibiotic resistance, let's learn the basics about the particulate matters.
Particulate Matters: The Invisible Troublemakers
Particulates or the atmospheric particulate matter (PM) are often defined as microscopic air pollutants made up of solid or liquid matter. From dust, dirt and smoke to soot and liquid droplets- all of them can be categorised under the tag of atmospheric particulate matter.
Presence of these microscopic particles in the atmosphere in exceeding levels often becomes the causative agent behind a number of serious threats to human body as well as to the environment.
How small are the particles?
The term fine particles, or particulate matter 2.5 (PM 2.5) refers to the group of particulate matters present in the air that are two and a half microns or less in width.
Micron is a unit of measurement for distance. An inch accounts for 25,000 microns. In fact the width of the considerably larger particles within the PM 2.5 size range would be about thirty times smaller than that of a human hair. The smaller particles ones are so small that several thousand of them could fit well within the period that we use at the end of this sentence.
PM 2.5: The carrier of antibiotic-resistance genes
The report suggests that the quantity of antibiotic resistance-determinant genes found in PM 2.5 surpasses the amounts found in sediments, soil, rivers and some engineering treatment systems which makes it very much possible for the humans to directly inhale antibiotic-resistant elements while breathing.
Antibiotic-resistance elements in PM 2.5 can be replenished from the natural environment and anthropogenic settings (eg, hospitals, farms, and sewage-treatment facilities) through wind action, water evaporation, dust transport, and wet or dry settlement spread over long distances and across regions.
Moreover, the PM 2.5 are capable of facilitating the horizontal gene transfer of antibiotic-resistant genes between bacteria.
Alongside the enevironmental dissemination of the resistant elements, the overuse of antibiotics in humans and animals also plays a pivotal role in emergence of antibiotic-resistant elements, which can be primarily discharged into environment via waste water, agricultural manure application, or evaporationwhich again can be transferred from environmental micro-organisms to human pathogens through drinking water, food and air inhalation.
Sources of PM 2.5
From industrial processes, road transport and domestic coal and wood burning- PM 2.5 can be found everywhere. This omnipresence of the hazardous particulate matter has made 7.3 billion people directly exposed to an unsafe average of annual PM 2.5 levels.
According to the lead author, Professor Hong Chen, of Zhejiang University, China, “Although air is recognised 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,”
Chen later delineated that the benefits of curbing air pollution will not only reduce the harmful effects of poor air quality, rather it could also play a major role in dealing with the unbridled spread of antibiotic-resistant bacteria.
Interpretation of the study for India
When asked about the rise in antibiotic resistance, Dr Rajeev Jayadevan, a member of the public health advisory panel of the Indian Medical Association, Kerala said, “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.”
“Now these tiny invisible particles or PM 2.5 can carry bacteria and the antibiotic resistant genes over long distances,” he later aded, as per a report by The Indian Express.
Dr Jayadevan also emphasised on the fact that more research is needed to confirm the authors’ hypothesis that when suspended air particles are breathed into the lungs or deposited in the environment, the genes could enter the bacteria that are already living in the human body and make them resistant.
“This is a certainly plausible hypothesis and makes a strong case for controlling air pollution,” he adds.
