Exposure to larger airborne particulates – common in everyday inner-city life – is linked to higher risk of asthma in children.

This is according to a Johns Hopkins University report.

Researchers found that children exposed large or ‘coarse’ airborne pollutants are more likely to develop asthma, and need the emergency room or hospital treatment for it, than unexposed children.

“Our study shows that the fraction of particulate pollution that is coarse contributes to the development and severity of asthma in children,” says Corinne Keet, M.D., M.S., Ph.D., associate professor of paediatrics at the Johns Hopkins University School of Medicine, and the study’s first author.

This report highlights the long-term negative effects of such relatively large airborne pollutants – a common fact of everyday inner-city life – on lung health, especially in children under 11 years of age.

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Related: How to prevent asthma attacks naturally

What is coarse particulate matter?

Fine particulate matter (PM 2.5) is defined as particles measuring 2.5 micrometres or smaller, and levels of it in the air are regulated and monitored by the EPA.

Coarse particulate matter (PM 10-2.5), which includes a mix of dust, sand and tire rubber emissions, measures from 2.5 to 10 micrometres. By comparison, a human hair is between 50 and 70 micrometres thick.

About the study

Researchers analysed asthma-related diagnosis and treatment data from the Research Data Assistance Center gathered on 7 810 025 children ages five to 20 years who lived in 34 US states.

They estimated coarse PM (PM 10-2.5) in each zip code using measurements of particulate matter collected in the EPA’s Air Quality System database from January 1, 2009, through December 31, 2010.

Keet and her team found that for each microgram/cubic meter increase in coarse particulate matter, asthma diagnosis increased by 0.6 percent, emergency room visits for asthma by 1.7 percent and hospitalisations for asthma by 2.3 percent.

Related: Air pollution can cut your life short by 10 years

Young lungs are more vulnerable to air pollution

The association between coarse particulate matter and asthma was even stronger for children 11 years old and younger.

For each microgram/cubic meter increase in coarse particulate matter, asthma diagnosis increased by 1.3 percent, emergency room visits for asthma by 3.3 percent and hospitalisations for asthma by 4.5 percent.

The authors speculate that the stronger association in the young reflects the probability that young children spend more time outdoors and their immature lungs are more vulnerable to air pollution.

Source: Johns Hopkins Medicine www.sciencedaily.com

While All4Women endeavours to ensure health articles are based on scientific research, health articles should not be considered as a replacement for professional medical advice. Should you have concerns related to this content, it is advised that you discuss them with your personal healthcare provider.