The correlation between pollution and lung health, particularly asthma, has been suspected since the industrial revolution, when cases of lung and respiratory illness skyrocketed with the rate of air pollution. A 2020 study by a group of researchers at Harvard Medical School has now looked at the many socioeconomic factors that come with this discovery in present day cities. For example, lower income families tend to live closer to major roadways, in densely populated cities, in regions with higher pollution. 

The study surveyed children living with asthma in urban northeastern American schools living in inner-city areas. The homes and schools of the children studied were mapped and their proximity to major roadways measured. The likelihood that a child experienced asthma symptoms, and the frequency that they experienced them, was shockingly different between children in schools close to major highways and those further away. 

In fact, for every 100 meters further from major roadways (in terms of school location), children were 29% less likely to report asthma symptoms in general, including need of an inhaler and asthma attacks. These results show us that children attending school near major highways, which are increasingly numerous across North America, have higher asthma rates and more severe symptoms, compared to students who do not go to school near major roadways.

Pollution is hard on our lungs, particularly when an underlying condition such as asthma is present. This study implies that more attention needs to be given to children attending school in inner-city, traffic-heavy districts, including monitoring of their lung health and asthma progression. These studies are difficult to perform because so many factors, such as socioeconomics and genetics, can also influence asthma and lung health, there is rarely a clear and direct cause-and-effect relationship. But, studies like this pave the way for future findings and improvement of conditions for asthmatics in city centers around the world.