Grantee Research Project Results
Rise in Particles in Indoor Air Increases Asthma Symptoms in Children
Researchers at Johns Hopkins found a direct correlation between increasing concentrations of particulate matter (PM) in indoor air and increased asthma symptoms in preschool children. Funded in part by a grant from EPA’s Science to Achieve Results program and the National Institute of Environmental Health Sciences (NIEHS), the study, published in the February issue of Environmental Health Perspectives, evaluated 150 inner city children with asthma in the Baltimore metropolitan area.
Researchers monitored the concentrations of both fine (2.5 microns or less) and coarse (2.5-10 microns) PM in each child’s bedroom. Samples were taken for three days at the start of the study and at 3 and 6 months. The health of each child was assessed through caregiver reports.
Researchers found that a significant increase in asthma symptoms was associated with higher indoor air concentrations of both coarse and fine PM. They found that for every increase of 10 micrograms of coarse PM per cubic meter of air (μg/m3), there was a 6 percent increase in the number of days the children displayed the asthma symptoms of coughing, wheezing, or chest tightness. Similarly, an increase in fine PM by 10 μg/m3, resulted in a 7 percent increase in the number of days the children were wheezing severely enough to limit their speech and a 4 percent increase in the number of days that rescue medication was used by the children.
The study demonstrated that both indoor coarse and fine PM distinctly affect respiratory health. The researchers found that although both coarse and fine PM increased asthma symptoms, only an increase in fine PM resulted in an increase in the number of days the children needed medication. The researchers also found a striking relationship between indoor air fine PM exposure and exercise-related asthma symptoms. The researchers concluded that decreasing PM concentrations in indoor air could provide a way to improve the health of children who have asthma.
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