Traffic fumes increase infection risk by damaging immune system, scientists warn

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Air pollution could increase the risk of infection by damaging the immune system, according to a study.

Scientists have demonstrated for the first time that nano-sized particles in traffic fumes reduce the body's ability to kill viruses and bacteria.

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

Dr Peter Barlow, who led the research, said: "This is an area of research that is very poorly understood.

"We were extremely concerned when we found that air pollution particles could inhibit the activity of these molecules, which are absolutely essential in the fight against infection.

"In light of these findings, we urge that strong action plans are put in place to rapidly reduce particulate air pollution in our towns and cities."

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

It found carbon particles could trigger changes in the molecules, potentially resulting in "an increased susceptibility to infection".

The implications are potentially 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.

Those with pre-existing lung conditions like asthma or chronic obstructive pulmonary disease are said to be especially vulnerable.