A spot of Christmas shopping in a busy town centre may damage your health as well as your bank balance.
Air pollution from diesel traffic can worsen lung function in people with asthma, a team of international researchers has said.
The first "real-life" study showed lung function was worse in patients who spent two hours on London's Oxford Street compared with nearby Hyde Park. The results are published in the New England Journal of Medicine.
Study leader Dr Paul Cullinan said previous studies had looked at the effects of pollution on a population level, for example comparing air quality with admissions to hospital, or in a laboratory, but not in a real-life scenario.
A total of 60 adults, half of with mild asthma and half with moderate asthma, walked for two hours along Oxford Street, where only buses and taxis are allowed, and then on a separate occasion walked for two hours in traffic-free Hyde Park.
Lung function tests done before and after the walks showed a greater reduction in lung capacity after participants had been exposed to diesel traffic than in the park and more inflammation in the lungs.
The negative effects were greater in those with worse asthma to start with.
Source - BBC