Children who grow up in towns and cities with high pollution levels are at increased risk of lung health issues or low functioning lungs. New research suggests that pollutants from vehicle emissions and fossil fuels have an adverse effect on a child's lung development and can also lower childrens lifetime breathing capacity.
In California, 90% of the children under the age of 14, live in areas that fail to meet state and federal air quality standards. 127 Million Americans half of the nation's population live in regions with air quality that does not meet federal standards for certain air pollutants.
The results of this new study, conducted by researchers at the University of Southern California Keck School of Medicine, are published in this week's issue of the New England Journal of Medicine.
"This is the longest study ever conducted on air pollution and children's health," said Dr. Kenneth Olden, director of NIEHS. "It shows that current levels of air pollution have adverse effects on lung development in children between the ages of 10 and 18."
Each year, pulmonary function data were collected from 1,759 children as they progressed from 4th grade to 12th grade. The researchers also tracked levels of air pollutants like nitrogen dioxide, acid vapor, elemental carbon, and particulate matter in the 12 Southern California communities where the children lived. The study encompassed some of the most polluted areas in the greater Los Angeles basin, as well as several less-polluted communities outside the Los Angeles area.
Over the eight year period, researchers found that children living in the most polluted communities had significant reductions in their "forced expiratory volume" — the volume of air that can be exhaled after taking a deep breath — as compared to children living in communities with cleaner air.
In healthy people, lungs grow to full capacity during the teenage years, but typically stop growing at age 18. Then, lung capacity gradually declines. Adults begin to lose lung function by 1 percent each year after age 20.
"Lung development in teenagers determines their breathing capacity and health for the rest of their lives," said John Peters, M.D., Hastings Professor of Preventive Medicine at the Keck School of Medicine. "The potential long-term effects of reduced lung function are alarming. It's second only to smoking as a risk factor for mortality. As lung function decreases, the risk of respiratory disease and heart attacks increases."
Deficits in lung function are associated with other short- and long-term effects. "If children or young adults with low lung function were to have a cold, they might have more severe lung symptoms, or wheezing," says W. James Gauderman, Ph.D., associate professor of preventive medicine at the Keck School and lead author on the study. "They may have a longer disease course, while children with better lung function may weather it much better."
Researchers are unsure how air pollution may retard lung development. Gauderman believes chronic inflammation may play a role, with air pollutants irritating small airways on a daily basis. Scientists also suspect that air pollutants might dampen the growth of alveoli, tiny air sacs in the lungs.
The research team will continue to follow the study participants into their early 20s, when their lungs will be fully mature. They want to find out whether the participants will experience respiratory symptoms, and if those who moved away from a polluted environment will show some improvement in lung function.
This research is part of the larger Children's Health Study, an ongoing study that was started in 1993. The study is the longest ever undertaken on the association between air pollution and children's health.
Some simple facts from the Coalition for Clean Air
General:
- Nitrogen Oxides + Hydrocarbons + Sunlight = Smog / Ozone
- In 1995, 3,518 tons of NOx, 2,214 tons of particulate matter, and 3,495 tons of reactive organic gases were emitted into California's atmosphere every day.
- In California, 90% of the children under the age of 14, live in areas that fail to meet state and federal air quality standards.
- 127 Million Americans half of the nation's population live in regions with air quality that does not meet federal standards for certain air pollutants.
- The lung damage caused by ozone exposure may be likened to the lung damage caused by cigarette smoking.
- People who live in cities with dirty air have blacker lungs than people who live in rural areas with less air pollution.
- Asthma is the most chronic disease of children, and the most common cause of childhood hospitalizations in California.
- The South Coast Air Basin had 40 days above the federal standard for ozone in 2000
- Gasoline and diesel powered vehicles produce 60% of the smog-forming pollutants in California.
- Pollutant levels inside vehicles may be 10 times higher than ambient air.
- Breathing air in Southern California can reduce one's life expectancy by 1 to 2 years.
Diesel: