Emergency room visits by children with asthma may be triggered by seasonal levels of airborne pollutants, a new study has found. File Photo by M. Dykstra/Shutterstock
Dec. 8 (UPI) -- Rising rates of emergency room visits among children with asthma may be linked with seasonal air pollution, even in areas with generally low levels, a study published Wednesday by the journal PLOS ONE found.
Based on data from urban and rural regions of South Carolina, coarse airborne particulate pollution -- particulate matter measuring 1.0 to 2.5 microns, known as PM1.0-2.5 -- and nitrogen oxide levels are linked to the rate of hospital ER visits among children with asthma, particularly during the fall, the data showed.
So-called fine particulate matter, which are microscopic pollutants that measure 2.5 microns, plays its largest role in fostering severe asthma symptoms in the summer, the researchers said.
PM typically comes fom industry and vehicle exhaust, according to the Environmental Protection Agency.
Meanwhile, relatively cool and dry conditions in the summer asthma season and increased temperatures in the spring and fall asthma seasons also are associated with increased risk for emergency room care, according to the researchers.
"With improved individual awareness of the seasonality of their own triggers, people with asthma may be able to introduce seasonally adaptive behaviors to reduce or prevent environmental exposures" to triggers, study co-author Matt Bozigar told UPI in an email.
"However, marginalized groups of people may not have the resources to make behavioral changes, such as staying inside in a place with filtered air on a hazy summer day, for example," said Bozigar, a post-doctoral associate with the Boston University School of Public Health.
Asthma is a long-term inflammatory disease of the lungs that causes wheezing, coughing, chest tightness and shortness of breath, according to the Centers for Disease Control and Prevention.
About one in 12, or 6 million, children in the United States have asthma, the agency estimates.
A study published in October by the Journal of Clinical Investigation identified 18 airborne pollutants that worsened asthma symptoms in children.
Separate analyses have indicated that breathing problems such as asthma are more common in low-income households, which are often concentrated in areas with higher air pollution levels.
For this study, Bozigar and his colleagues estimated air pollution levels across South Carolina and compared with data on hospital ER visits related to asthma among children in the state.
From 2006 and 2014, 48% of ER visits related to asthma for children in South Carolina occurred during the fall, or between Aug. 20 and Dec. 31, while 26% were reported during the spring, between March 1 and May 31.
The remainder of ER visits for children with asthma in the state occurred during the summer and winter, which are relatively mild seasons for the breathing disorder there, according to the researchers.
Elevated levels of PM1.0-2.5 in the fall, which often brings warmer, wet weather to the region, increased the risk for hospital ER visits among children by 14%.
Similarly, higher levels of nitrogen oxides in the air increased the risk for hospital ER visits for asthma among children by 3% during the same season, the researchers said.
"Individuals with asthma could benefit from understanding that their own asthma symptom rhythms may be influenced by different things at different times of the year," Bozigar said.
"What triggers asthma from the environment, such as air pollution, appears to change by season [and these] asthma exacerbations do not follow normal astronomical seasons," he said.