Oct. 7, 2009 -- Cleaner air resulting from federal pollution laws may have significantly reduced the prevalence of ear infections in children, a new study shows.
The study, presented at the 2009 American Academy of Otolaryngology-Head and Neck Surgery Foundation in San Diego, analyzed U.S. data on 126,060 children (average age 9 years) from 1997 to 2007, looking at how many instances of ear infections occurred in a one-year period. They also used air quality data from the Environmental Protection Agency (EPA) for the same period, focusing on air pollutants such as carbon monoxide, nitrous dioxide, sulfur dioxide, and particulate matter.
Researchers say frequent otitis media, defined as three or more ear infections in a 12-month period, decreased as air quality improved, as measured by the EPA. The researchers also looked for an association between air quality and respiratory allergy, but found none.
The researchers write that their work has both medical and political significance, suggesting that toughening quality requirements in the Clean Air Act of 1990 is reaping dividends.
Revisions in the act gave the EPA more authority to implement and enforce regulations aimed at cleaning the air and led to improvements in health quality measures such as otitis media, which is one of the most common illnesses among children, with direct and indirect costs in the $3 billion to $5 billion range annually.
The researchers, led by Neil Bhattacharyya, MD, of the department of otology and laryngology at the Harvard Medical School, conclude that better air quality is "significantly associated with lower prevalence of pediatric ear infections but is not associated with the prevalence of pediatric respiratory allergy."
Continuing efforts to clean up the air will decrease ear infection rates further, the researchers predict. They note that previous smaller studies have suggested a connection between cleaner air and reductions in ear infections.
"The current study reports a statistically significant association between improvements in air quality and a reduction in frequency of ear infections prevalence," the researchers write. "Otitis media is a major cause of morbidity in children and is one of the most common reasons for children to undergo medical care."