MedWire News: Exposure to air pollution from traffic triggers wheezing symptoms in susceptible children younger than 3 years, Danish researchers conclude from initial results from the Copenhagen Prospective Study on Asthma in Children (COPSAC).
"Follow-up of the cohort at later ages will determine the effect of these associations on the development of asthma," write Zorana Andersen (Copenhagen University) and colleagues in the journal Thorax.
Andersen and colleagues used daily symptom records from the birth cohort of 205 children of mothers with asthma from COPSAC to determine the short-term effect of particulate and gaseous air pollution on wheezing symptoms during the first 3 years of life in a high-risk population.
"Understanding the effects of early air pollution exposures on the development and triggering of wheeze may give important clues to the role in the development of asthma later in life," the authors explain.
The team found significant positive correlations between concentrations of particulate matter less than 10 µm in diameter (PM10), nitrogen dioxide (NO2), nitrogen oxide (NOx), and carbon monoxide (CO) and wheezing symptoms in infants (age 0-1 year) with 3 to 4 days delay.
Each interquartile range increase in exposure to PM10, NO2, NOx, and CO, led to respective 23%, 42%, 30%, and 47% increases in wheezing symptoms in infants. However, only the traffic related gasses, NO2 and NOx, showed significant effects throughout the first 3 years of life.
"The finding of traffic relevance in the triggering of wheezing in infants is in agreement with recent evidence associating infant wheezing to proximity to traffic," the authors write.
They conclude: "We found independent effects of PM10 and traffic related pollution... for the triggering of wheezing symptoms in young children genetically predisposed to asthma."
"Infants were found to be particularly vulnerable."
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