Long-term pollution link to asthma

People who are exposed to air pollution for a long time are much more likely to have poorly-controlled asthma, researchers say.

Experts already know there is a link between air pollution and the condition, but there are few studies on how long-term exposure affects people’s ability to manage their symptoms.

More than 480 people with asthma were asked about their condition, including their use of medication over the last three months to a year, number of asthma attacks and whether they required hospital treatment.

Some 44 per cent of the group had well-controlled asthma, 29 per cent had partially controlled and 27 per cent had uncontrolled asthma.

Uncontrolled asthma includes symptoms such as being woken up in the night with shortness of breath, using quick-acting inhalers a lot, using steroids to control asthma and going to hospital with symptoms.

The team of researchers from France then calculated each person’s exposure to levels of ozone (O3), nitrous oxide (NO2) and particulate matter (PM10) at their home address, using data from the French Institute of the Environment.

Writing in the Journal of Epidemiology and Community Health, the researchers said levels of ozone and particulate matter were strongly associated with poorer asthma control.

Long-term exposure to ozone caused a 69 per cent increased risk of uncontrolled asthma, while particulate matter increased the risk by 35 per cent.

Women and older people were more likely to have poorly-controlled asthma.