Coming HEI study suggests air pollution regulations likely contributors to improvements in air quality and children’s health
The Health Effects Institute (HEI) will soon publish a study by Frank Gilliland and his colleagues at the University of Southern California the findings of which suggest that US and California regulations directed at reducing emissions of mobile-source pollutants were likely contributors to improvements in air quality between 1985 and 2012 that were in turn associated with improvements in children’s respiratory health.
The researchers analyzed pollutant monitoring and pulmonary health effects information as well as multiple covariates that they had collected over more than 20 years from participants in several cohorts recruited into the Children’s Health Study (CHS) in Southern California. The children lived in communities that differed in sources and levels of the outdoor pollutants PM, NO2, and ozone.
Eighteen major policy actions had been implemented in Southern California during the study period to reduce pollution from transportation sources.
The team found that emissions of pollutants and their precursors, as well as ambient levels of most air pollutants, decreased over that time—in some cases significantly.
The study’s major health findings were that decreases in long-term community-level averages of pollutants across cohorts—particularly NO2 and PM2.5—were associated with improved growth of children’s lung function. Decreases in levels of NO2 , PM2.5, PM10, and O3 were also associated with decreased prevalence of respiratory symptoms, particularly in children with asthma.
The Review Committee for the study noted that given the large number of policy control measures taken, sometimes with overlapping time frames, it was difficult to attribute the emission and pollutant reductions to specific policies. The Review Committee concurred with the overall findings of health improvement in the teenagers, but it also noted that changes in lung function and respiratory symptoms were not uniform across the communities in relation to decreases in pollutants.
This suggests that some unexplored inter- and intra-community factors also were likely to be important. Future research can explore in more depth the nature of these associations, in particular the question of whether they are likely to be causal.
Research Report 190, The Effects of Policy- Driven Air Quality Improvements on Children’s Respiratory Health, will be available for downloading from the HEI website.
HEI is a nonprofit corporation chartered in 1980 as an independent research organization to provide high-quality, impartial, and relevant science on the health effects of air pollution. HEI typically receives balanced funding from the U.S. Environmental Protection Agency and the worldwide motor vehicle industry. Other public and private organizations periodically support special projects or certain research programs.