A 20-year study has found that Southern California children today are breathing easier than their counterparts thanks to cleaner air in Los Angeles.
In a study published in the New England Journal of Medicine, researchers for the University of Southern California Children's Health Study took lung measurements to determine levels of development in children 11 to 15 years old and discovered that those part of the study between 2007 and 2011 exhibited large improvements compared to children at the same age group who participated in the study between 1994 and 1998 as well as 1997 and 2001.
Studies have explored the effects of pollution on child health by examining different locations to compare variations in air quality. However, it has always been a challenge to rule out specific factors that may influence differences in health in communities. Researchers found a workaround by following over 2,000 children from the same location for over 20 years, adjusting data for gender, age, height, ethnicity, the presence of respiratory illness as well as other factors. Results offered strong evidence that improving air quality on its own can promote lasting health benefits when the improvement was done during a child's growing years.
Gains in lung measurement recorded by the study were present regardless of ethnicity, education level, exposure to tobacco and pets and other factors. Those already sick also got better, with children with asthma even improving twice as much as those without the condition.
As this is the first time the study yielded positive numbers, researchers admit to feeling strange documenting positive results. Previously, the long-running study revealed the negatives of poor air quality, highlighting an increase in stunted lung development in children from heavily air-polluted areas. Children living near and along busy roads were also shown to have higher risks of developing asthma.
"We expect that our results are relevant for areas outside southern California, since the pollutants we found most strongly linked to improved health - nitrogen dioxide and particulate matter - are elevated in any urban environment," said W. James Gauderman, a preventive medicine professor from USC's Keck School of Medicine and lead author for the study.
The study received funding support from the National Institute of Environmental Health Sciences, the Hastings Foundation, the California Air Resources Board and the Health Effects Institute. Other authors include: Frank Gilliland, Fred Lurmann, Roger Chang, Edward Rappaport, Rob McConnell, Kiros Berhane, Edward Avol and Robert Urman.
Photo: Stefano Montagner | Flickr
