The Air Resources Board (ARB) sets California’s ambient air quality standards (AAQS) to protect the most sensitive subpopulations; such as children, the elderly, or people with a pre-existing disease, for example cardiac patients or asthmatics. However, there was a concern that these standards do not adequately protect Californians from the impacts of long-term exposure to air pollutants.
Historically, the focus of air pollution health effects research has been to study effects associated with short-term exposure (often as short as hours) to relatively high concentrations of ambient air pollutants. When viewed from this perspective, air pollution control strategies have proven to been relatively effective. In many areas of California the frequency of exceedance of the AAQSs and the peak concentrations recorded have decreased markedly. As a result, the acute respiratory effects and other short-term consequences of exposure to high concentrations of some air pollutants also appear to be on the decline. However, little information existed on the health effects that may be associated with long-term exposure (measured in years) to low-to-moderate levels of the various pollutants, or combinations of pollutants. It was also not known how repeated exposures to high concentrations of pollutants, especially in combination with other pollutant exposures, affects health.
Visit the Air Resources Board website for more specifics on the study, such as the region and health assessments that were administered.
Results and Conclusions from the Study:
- Air pollution harms children’s lungs for life. Children exposed to higher levels of particulate matter, nitrogen dioxide, acid vapor and elemental carbon, had significantly lower lung function at age 18, an age when the lungs are nearly mature and lung function deficits are unlikely to be reversed.
- Children that were exposed to current levels of air pollution had significantly reduced lung growth and development when exposed to higher levels of acid vapor, ozone, nitrogen dioxide and particulate matter which is made up of very small particles that can be breathed deeply into the lungs.
- Children living in high ozone communities who actively participated in several sports were more likely to develop asthma than children in these communities not participating in sports.
Children living in communities with higher concentrations of nitrogen dioxide, particulate matter, and acid vapor had lungs that both developed and grew more slowly and were less able to move air through them. This decreased lung development may have permanent adverse effects in adulthood. - Children who moved away from study communities had increased lung development if the new communities had lower particulate matter levels, and had decreased lung development if the new communities had higher particulate matter levels.
Days with higher ozone levels resulted in significantly higher school absences due to respiratory illness. - Children with asthma who were exposed to higher concentrations of particulate matter were much more likely to develop bronchitis.