Exposure to coarse particulate matter (PM) pollution may increase the prevalence of asthma in US children enrolled in Medicaid, according to a new study.

Lead author Corinne A. Keet, MD, PhD, Associate Professor at John Hopkins University School of Medicine, Division of Pediatric Allergy and Immunology, told MD Magazine that the most striking finding of the study was that PM levels — that is, large-sized particulate pollution — were independently associated with asthma prevalence and exacerbations.

“This is important because this type of pollution is not currently regulated and much less attention has been given to it,” Keet said.

Fine PM usually originates from combustion or reactions in the atmosphere, while coarse PM is created from grinding and resuspension of solid materials.