Why it is in news?

• Exposure to air pollution on the way to school can have damaging effects on growth of children's working memory, suggests new research.

Impact on children

• The study, published in the journal Environmental Pollution, found an association between a reduction in working memory and exposure to fine particulate matter (PM2.5) -- fine inhalable particles that have diameters of 2.5 micrometres or less -- and black carbon -- a pollutant directly related to traffic -- during the walking commute to and from school.
• The findings of an earlier study had shown that 20 percent of a child's daily dose of black carbon is inhaled during urban commutes.
• The results of earlier toxicological and experimental studies have shown that these short exposures to very high concentrations of pollutants can have a disproportionately high impact on health"
• The detrimental effects may be particularly marked in children because of their smaller lung capacity and higher respiratory rate.

interquartile range (IQR)

• The interquartile range (IQR) is a measure of variability based on dividing a data set into quartiles.
• An interquartile range increase in PM 2.5 and black carbon levels were associated with a decline of 4.6 percent and 3.9 percent, respectively, in the expected annual growth of working memory, the study said.