Researchers who have monitored the impact of contaminated air around Los Angeles say improvements in air quality have led to better health among children.
The 20-year study by researchers from the University of Southern California, published this week in The New England Journal of Medicine, included more than 2,000 children between the ages of 11 and 15. They lived in four inland cities where wind patterns and topography tend to trap air pollution, and the coastal city of Long Beach, home to a busy port.
Levels of fine particulates were down by 50 percent in these communities, and nitrogen dioxide levels were down by one-third. Lead author James Gauderman said that in these areas, cleaner air has led to stronger lungs in children.
“This is an incredible success story, because despite increased traffic and economic activities, the air quality in the Los Angeles region has actually gotten better," he said. "And this study shows that as a result, the lung development and the lung capacity of our children has also gotten much better.”
That will result in fewer breathing problems and heart problems later in life, and better lungs may extend the children’s average life span.
The changes were brought about through the action of local, state and federal regulators who clamped down on emissions from cars and other sources, said researcher Frank Gilliland.
“It’s many, many different things, but it’s a concerted effort to control sources, and it’s over a long period," he said. "You have to have a long horizon. It’s improved vehicles, improved fuel sources, lower-sulfur diesel, better diesel engines in heavy-duty trucks, port regulations. All these things come together to reduce the emissions, and all come together to result in better air.”
Efforts to bring down pollution levels at the ports have paid off, said Long Beach activist Mark Lopez, but he worries about the future.
“The increased air quality equals increased health, and so if we start to digress, if we start to move backward when it comes to air quality, we know it’s going to mean worse health for our children," he said.
Cities in China and India face worse air pollution than Los Angeles, and researcher Edward Avol said the study has a message for those places.
“The particles and the gases that we tracked as important in terms of health the Southern California air are very similar to the kinds of combustion processes and the kind of combustion contaminants that you’d have anywhere in the world," he said. "And so cleaning up the air in other parts of the world, one ought to reasonably expect you’d get the same kind of health benefits on children living there.”
The health researchers said pollution controls have proven benefits for children at a time when their lung development will help determine their future health as adults. But as the region continues to grow, the researchers said, the challenge is to keep pollution levels low.