How Does Pollution Affect the Spread of Disease?

It’s long been known that exposure to air pollution increases the risk of contracting cardiovascular and respiratory diseases; it’s less clear exactly why this comes about. Now, a new study from the University of Milan aims to pinpoint the missing link between pollution and disease.

Identifying a correlation between different bacteria living within our respiratory tracts and the diseases they can engender, researcher Jacopo Mariani and his team aimed to find out whether these bacteria were being affected by poor air quality.

Digging a little deeper

It’s a well-documented fact that exposure to contaminants such as particulate matter 2.5 (PM2.5), nitrogen oxides (NOx) and carbon dioxide (CO2) can cause respiratory difficulties and heart complications. Earlier this year, a study even suggested that air pollution could alter the effectiveness of antibiotics as well as increasing the potential of disease.

However, the direct correlation between air pollution and an increased incidence of disease has never been fully understood. For the first time, Mariani and his team attempted to investigate this link by analysing nasal swabs from 40 residents of Milan and its surrounding environs. The results of their study further suggested that pollution can have a direct effect on bacteria – including the friendly variety.

Bad rep for bacteria

Inside our bodies there is a thriving community of microbes and bacteria. While they might have a bad reputation, the majority of these are harmless and in fact, certain strains are actually beneficial to our health.

For example, Actinobacteria is the chief variety in healthy microbiomes and though its exact relationship with the body is unknown, it’s believed to have anti-inflammatory and anti-microbial properties.

On the other hand, there are obviously malignant bacteria as well, such as Moraxella. This particular strain is known to be responsible for the contraction and exacerbation of respiratory infections.

Illuminating results

Mariani and his team used genetic sequencing to pinpoint various bacteria in the swabs of the 40 volunteers. They then cross-referenced these results with the air quality levels as recorded by monitoring stations in the vicinity of where the volunteers worked and lived.

The results showed that areas with higher levels of particulates had a direct and damaging effect on the diversity of bacteria within the volunteers’ airways. In particular, Actinobacteria was found to be less prevalent in those exposed to the pollution, while Moraxella was found at elevated levels.

“You’re inhaling stuff that might cause inflammatory responses in your airways, so it’s extremely likely that the airway microbiome is a sort of mediator between pollution and respiratory effect,” explained Lidwien Smit from Utrecht University. “But this area of research is still in its infancy.”

Steer clear of pollution hotspots

While further studies are required in order to fully understand the correlation between pollution and disease, those living in urban environments can already take advantage of continuous emissions monitoring systems (CEMS) and the “pollution maps” they create to help avoid pollution hotspots.

Such technology is increasingly popular in the UK, EU and USA, but there has also been recent growth in the CEMS market in developing countries, as well. Clearly, staying informed about the cleanliness of the air we breathe is a priority to humans all over the world.