(RxWiki News) Those fighting for better pollution practices in one US state last week got a breath of fresh air.
A new study found that air pollution levels in Southern California dipped over the years — and the respiratory health of kids in the area increased.
"Air-pollution levels have been trending downward progressively over the past several decades in Southern California, as a result of the implementation of air quality–control policies," explained the authors of this new study, led by W. James Gauderman, PhD, of the Department of Preventive Medicine at the University of Southern California, Los Angeles.
Dr. Gauderman and team wanted to explore how these air quality improvements might be tied to the respiratory health of children in the area. To do so, they used data from the Children's Health Study. This included 2,120 Southern California children.
These children were divided into three different groups depending on when they participated: 1994 to 1998, 1997 to 2001 and 2007 to 2011.
These kids were 11 years old on average when their study period began. They were about 15 when the study period finished.
Dr. Gauderman and team measured the children's lung function with several tests, including the forced expiratory volume in 1 second (FEV1) test. This test measures the amount of air expelled during the first second of forcibly exhaling.
During the recent period of dropping air pollution, the respiratory health of the children improved, Dr. Gauderman and team found. This was true in both boys and girls, as well as in those with and without asthma.
Among the earliest group of patients, 7.9 percent had an FEV1 level that was considered "clinically low" at age 15. For the next group, this was true for 6.3 percent of the kids. By the time the final group reached age 15, this number had dropped again — to only 3.6 percent.
"Reduced lung function in adulthood has been strongly associated with increased risks of respiratory disease, cardiovascular disease, and premature death," Dr. Gauderman said in a news release. "Improved air quality over the past 20 years has helped reduce the gap in lung health for kids inside, versus outside, the LA basin."
Dr. Gauderman and team called for further research in more communities to explore the tie between air pollution and lung health.
This study was published March 5 in The New England Journal of Medicine.
A number of groups funded this research, such as the California Air Resources Board and the National Institute of Environmental Health Sciences. One study author received research funds from a California air-quality-violations lawsuit settlement.