Smoggy Schools: Conclusion
Will the proposed standard fully protect childrens's health?
California health officials were charged with evaluating the protectiveness of existing air quality standards for infants and children. They were asked to pay special attention to the interaction of multiple pollutants known to target the same body systems, and to assure an adequate margin of safety that considers people who are the most sensitive to smog. The state's proposal for a more protective daily ozone standard of 70 ppb is an important first step toward protecting the health of children, the elderly and people with respiratory diseases who are more susceptible to smog.
We applaud this effort but caution that even the new standard might not fully protect sensitive groups from long-term effects of smog exposure. California lacks a strong enforcement mechanism to enforce their air quality standards for stationary sources. The state has authority to regulate consumer products and engine emissions, two major sources of future smog reduction. Local air quality managers are obligated to reduce emissions from industrial facilities inorder to meet the standards 'as expeditiously as possible.' However, the state should have the authority to levy fiscal penalties for regions that don't make a timely effort to reduce smog. Without this authority efforts to control smog are less protected from the political whims of state or local governments.
Additionally, dozens of epidemiological and direct human exposure studies find low-level effects at or below 80 ppb leaving little or no margin of safety for those at special risk. Consider the evidence:
- A study of Southern California schoolchildren with asthma showed significant associations between asthma symptoms and hourly and daily ozone concentrations below the current and proposed standards. Children with the least frequent asthma symptoms had a 2-fold increase in symptoms when short-term ozone exceeded 58 ppb and daily concentrations exceeded 46 ppbboth measurements significantly below the current and proposed California standards. Within this group the children who weren't taking asthma maintenance medications had an even more dramatic response to ozone. [Delphino 1998]
- Southern California studies associating ozone levels with new asthma diagnoses and respiratory absences from school both took place in regions where the air quality was not considerably higher than the proposed daily standard. The average daily ozone level in these 'smoggier' communities where children were 3-times more likely to develop asthma, was only 60 ppb between January and June. [Peters 2004] The study of school absences took place in a community where the daytime average ozone level ranged from 31 to 65 ppb. [Gilliland 2001]
- At ozone concentration of just 63 ppb, asthmatic children using maintenance medications experienced significantly more chest tightness and shortness of breath than they did at lower ozone levels. [Gent 2003]
- Controlled studies exposing healthy adult men to 80 ppb ozone for a 6.6-hour study found that one-quarter of the participants had a 20 to 40 percent reduction of their lung capacity, indicating a significant, negative effects on their health. [Folinsbee 1991] Indeed the State's report acknowledges that "(I)ncreased respiratory symptoms, including hyperreactivity of the airways and increased inflammation have also been noted at concentrations below 80 ppb." [ARB(1) 2005]
- Significant reductions in exercise performance have been reported for healthy adults when exposed to 60 ppb ozone for less than 2-hours. [ARB(1) 2005 citing Linder 1988]
Human studies have shown that some people are much more affected by smog than others. It is nearly impossible to predict who will be most sensitiveage, gender, diet and genes don't seem to determine sensitivity. [ARB(1) 2005] The State's own assessment acknowledges that they cannot assure that everyone will be protected by the new ozone standard. "Given the current state of the science . . . it is not possible to set standards for ozone that absolutely protect all individuals." [ARB(1) 2005]
The academic review committee that evaluated the standard cautioned that little information existed to evaluate the sensitivity of children with chronic lung diseases. They caution that children with "bronchopulmonary dysplasia, asthma and cystic fibrosis could be at special risk but, with the possible exception of asthma, there has been little research effort in these areas." [ARB(4) 2005] In conclusion, the academic review committee, "is concerned that the proposed standards, although an improvement over current status, can still allow effects in susceptible populations," [ARB(4) 2005] and listed the chamber studies showing long-term effects at 80 ppb, as well as the lack of studies that 70 ppb ozone is indeed without effect. [ARB(4) 2005] The committee also asked ARB to justify why they felt comfortable extrapolating studies subjecting participants to a 6.6-hour exposure into an 8-hour standard. They suggested the state consider a 6.6-hour standard, which would be more protective than a longer standard.
We urge further research into the effects of ozone on the developing fetus and child. Particular care should be given to studying the risks of ozone exposure for people with asthma or other pre-existing illnesses that would exacerbate the effects of ozone pollution.