Los Angeles – Improved air quality was associated with declining symptoms of asthma and other respiratory problems in kids Southern California, according to a study conducted in Southern California and published in the Journal of the American Medical Association (JAMA). Over the course of two decades, reduced levels of air pollution were linked to lower rates of bronchitis among children of all ages.
Experts are yet to find out the reasons, but there is sufficient evidence to say that the symptoms of respiratory problems such as congestion, coughing, bronchitis and phlegm in children who did not have a cold or the flu were significantly reduced as air quality improved.
The research team tracked three group of children, ages five to 18, living in eight southern California communities. One group was tracked from 1993 to 2001, another from 1996 to 2004 and the third group from 2003 to 2012. The 4,602 youths involved in the study entered the research at an average age of eight.
Families were asked to take an annual questionnaire about the prevalence of bronchitic symptoms.
A 47 percent decline in levels of particulate matter was linked to a 32 percent decrease in the likelihood of bronchitic symptoms in 10-year-old asthma patients, as reported by Kiros Berhane, Ph.D., of the University of Southern California in Los Angeles, and his research team.
A 49 percent decrease in the air pollutant was linked to a 21 percent reduction of symptoms in asthmatic children. Those kids with no asthma-related issues had a reduced chance of developing bronchitis by 16 percent, the study shows.
“I think we can safely say this is one of the clearest pieces of scientific evidence to say reduction of air pollution can lead to improvement in respiratory health for children,” said lead author Kiros Berhane, from the University of Southern California (USC) in Los Angeles.
Berhane and his colleagues from USC said changing policies have played a significant role in air pollution decline since 1992. Study co-author Edward Avol pointed out that there has been replacement of trucks, school buses and other forms of transportation that contributed to high pollution levels.
The benefits of air quality improvement are not limited to children with asthma
Researchers remarked that all children have benefited from air quality improvement, regardless of whether they had asthma. And Jay Portnoy, of Children’s Mercy Hospital in Kansas City, noted that the link between reduced pollution levels and lower rates of respiratory problems remained significant even after taking into account other factors like income, race, having pets, obesity, health insurance coverage and exposure to tobacco smoke.