Traffic pollution worsens asthma in kids

Traffic pollution, especially in cities, adversely affects the respiratory health of children with asthma, the results of a new study indicate.

Previous studies have suggested that traffic pollution, and diesel particles in particular, may have a greater effect on respiratory health than other pollutants. This is significant as a large proportion of pollution in cities originates from motor vehicles. However at present, no studies have clearly linked different types of vehicular traffic exhaust to the respiratory health of either asthmatic or healthy children.

A team of Mexican researchers followed the progress of 147 children with asthma and 50 children without the condition. All were aged between six and 14.

Parents kept a daily record of coughing and wheezing experienced by their children, as well as medication usage. Atmospheric levels of the pollutants ozone, nitrogen dioxide and diesel particles were recorded in the children’s areas during the study.

The amount and type of traffic was also recorded in order to evaluate whether diesel-fuelled vehicles had a greater impact upon respiratory health than pollution from other vehicles.

The study found that in children with asthma, coughing, wheezing and medication usage was associated with increased levels of atmospheric pollutants. In the children without asthma, increased coughing was only seen with higher levels of nitrogen dioxide.

Furthermore, children living in areas with high levels of traffic experienced a worsening of asthma symptoms more often. They also recorded a greater use of medication.

Small buses for public transport running on petrol/natural gas, and larger buses and trucks running on diesel, were more strongly associated with a worsening of symptoms.

The researchers pointed out that all types of traffic exhaust have an adverse effect on children’s respiratory health and that given the proximity of many schools to roads with heavy traffic, ‘these results have significant implications for public health policy within cities in Mexico and the rest of the world’.

Details of these findings are published in the journal, Respiratory Research.

For more information on asthma, see our Asthma Clinic at...http://www.irishhealth.com/clin/asthma/index.html

[Posted: Sat 15/11/2008]