A recent study carried out in Munich examined over 3000 6 year olds from birth; a longitudinal study to answer the question, does growing up near a busy road result in a higher incidence of allergies. Scientists specifically examined fine dust, diesel soot and nitrogen dioxide and found that children growing up near busy streets were more susceptible to allergies. Specifically, exposure to fine dust predisposed the children towards pollen sensitivities, and exposure to nitric oxide was linked to higher levels of eczema. Nitric oxide comes from car exhaust and power plants. Nitrogen dioxide is a different, and equally poisonous air pollutant. NO2 gives smog its characteristic brown color. In summary, children living within 50 meters of a busy road were 1 to 50% more likely to develop allergy related problems.

John Hollingsworth, the leader of a Duke University study of the effects of ozone on lung tissue, found that high levels of pollution generated ozone killed bacteria killing cells in the lungs, making them susceptible to pathogens. In a similar vein, Dr. Andre Nel of UCLA found that high air pollution makes allergies and asthma worse. People who experience severe allergy symptoms may want to watch the pollen and air pollution ratings every day when planning activities outside.

So, what we knew intuitively as parents has been backed up by research.