A larger percentage of child asthma cases are caused by traffic pollution than was previously thought, it is believed.

Traffic pollution causes many child asthma cases

Mar 28 2013

Traffic pollution is the cause of a significant number of child asthma cases, according to a new study.

Research published in the European Respiratory Journal showed that the impact of traffic pollution near busy roads on childhood asthma in European cities can be compared to the effect of passive smoking.

It was found that some 14 per cent of chronic childhood asthma cases are due to exposure to traffic pollution near congested roads.

It was also estimated that air pollution was responsible for a total of 14,400 episodes of asthma symptoms and 260 hospitalisations due to the respiratory disease. This accounts for 15 per cent of acute events.

Meanwhile, it is believed that between four per cent and 18 per cent of asthma cases in children are linked to passive smoking.

The research was conducted in ten European cities: Barcelona, Bilbao, Brussels, Granada, Ljubljana, Rome, Sevilla, Stockholm, Valencia and Vienna.

Across these cities, the annual weighted mean for particulate matter PM10 was found to be 30 micrograms per cubic metre. For nitrogen dioxide this reading was 39mg per cubic metre.

Annual mean limits set by the European Union stand at 40 micrograms per cubic metre for both PM10 and nitrogen dioxide.

It was found that on average 31 per cent of the population of the ten cities lived within 75 metres of a busy road. Furthermore, the homes of 53 per cent were within 150 metres of this type of roads.

It was once thought that traffic pollution was merely a trigger for asthma symptoms. However, calculations did not allow for the chronic asthma cases that are caused by the range of pollutants specifically found near congested roads, such as nitrogen dioxide and particulate matter.

Lead author of the study, Dr Laura Perez, of the Swiss Tropical and Public Health Institute, said: “Air pollution has previously been seen to trigger symptoms but this is the first time we have estimated the percentage of cases that might not have occurred if Europeans had not been exposed to road traffic pollution.”