Scientists at Edinburgh Napier have revealed that air pollution can make people more vulnerable to infection.

A team led by immunology expert Dr Peter Barlow has demonstrated for the first time that nano-sized particles found in traffic fumes can damage the immune system’s ability to kill viruses and bacteria.

While the potential link between air pollution and illness has been the subject of much debate, the work at Edinburgh Napier University is the first to show this effect and has significant human health implications.

The development is expected to prompt calls for the government to step up efforts to tackle air pollution following its recently announced plans to ban the sale of new diesel and petrol cars by 2040.

The Edinburgh Napier study focused on ‘antimicrobial peptides’, tiny molecules found in the immune systems of humans and animals which increase in response to infection.

Researchers at the School of Applied Sciences recently revealed these peptides have virus-killing properties which could prove crucial in developing a cure for the common cold.

However, the new paper, published in The Journal of Immunology, reveals that particles found in air pollution can prevent peptides working properly.

Study Director Dr Barlow and researcher Dr Fern Findlay, working in collaboration with the US Centres for Disease Control and Prevention, and the Midlothian-based Moredun Research Institute, found carbon particles could trigger changes in the antimicrobial peptides, potentially resulting in “an increased susceptibility to infection”.

The implications are profound for people living in areas of high air pollution, who breathe in huge concentrations of particles every day or absorb them through skin contact, especially those with pre-existing lung conditions like asthma or COPD.

Scotland now has 38 Air Quality Management Areas and air pollution is estimated to cause the early death of 2,500 people in Scotland. The paper can be read here.