Traffic Pollution Exacerbates Symptoms in Asthmatic Children

Researchers at the Mexican Institute Nacional de Salud Publica (Cuernavaca, Morelos, Mexico) examined 147 asthmatic children and 50 non-asthmatic children (between the ages of 6 and 14) who were followed for 22 weeks to correlate the effect of pollutants with the worsening of respiratory symptoms. The 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 Mexico City during the study. The amount and type of traffic in the areas inhabited by the volunteers 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 results showed that in the asthmatic children, coughing, wheezing, and medication usage was associated with increased levels of atmospheric pollutants. However, in the healthy volunteers, increased coughing was only seen with higher levels of nitrogen dioxide. Children living in areas with high levels of traffic more often experienced worsening of asthma symptoms and greater use of medication. Small buses for public transport running on petrol or natural gas, and larger buses and trucks running on diesel, were more strongly associated with worsening of symptoms. The study was published in the November 16, 2008, edition of the open access journal Respiratory Research, a publication of BioMed Central,

"Although oxidative stress has been shown to be a major underlying feature of the toxic effect of air pollutants, there is still a need for a better understanding of the actual mechanisms by which pollutants cause exacerbation of respiratory symptoms,” concluded lead author Isabelle Romieu, M.D., MPH, Sc.D. "These results have significant implications for public health policy within cities in Mexico and the rest of the world”.

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Institute Nacional de Salud Publica
BioMed Central