It was thirty years ago, give or take a day, when the Jimi Hendrix Experience (Jimi Hendrix, Noel Redding and Mitch Mitchell) burst upon the rock-n-roll scene with the psychedelic Purple Haze. But EPA, the American Lung Association and their surrogates apparently think people are still so stoned that they can blow their air pollution junk science right past everyone.
In the latest EPA-funded, American Lung Association-published, junk science-fueled study titled Summertime Haze Air Pollution and Children with Asthma, Thurston et al. conclude that
...air pollution can be a major contributor to the respiratory problems experienced by children with asthma during the summertime months.
How convenient. And just in time to support EPA's proposal lowering the air pollution standards for ozone and particulate matter. Of course what would you expect given that:
- the EPA has given the American Lung Association $4 million since 1990;
- the American Lung Association (by suing EPA to issue new air pollution standards) is helping EPA expand its regulatory power; and
- George Thurston has received $383,000 from EPA to study air pollution.
But let's take a look at the science of Summertime Haze anyway.
Thurston et al. based their conclusion on a study of 166 children (ages 7-13) attending "asthma camp" (their term, not mine) downwind of New York City during the last week of June 1991 (52 kids), 1992 (58 kids) and 1993 (56 kids).
Researchers collected health data from the children on (1) the number of daily asthma exacerbations (as indicated by the total number of unscheduled uses of asthma medication); (2) the incidence of respiratory symptoms reported by the kids, and (3) daily measurements of peak expiratory flow rate. These data were then correlated against air pollution data, including daily measurements of ozone, fine particulate matter.
As reported in the study, there were, on average, 20 unscheduled uses of medication each day among each group of children. On the day with the highest level of air pollution, there were 28 unscheduled uses. Thurston et al. attributed this entire increase in unscheduled medication use to air pollution.
Thurston et al. concluded that the highest pollution day caused a 40 percent increase (relative risk = 1.4) in asthma exacerbation and chest symptoms, over the mean rates for these health effects. In terms of health effects this would mean that on the day with the most air pollution: 1 of 7 moderately-to-severely asthmatic children would use his/her medication 1 extra time per day; and 1 of 5 moderately-to-severely children would have 1 additional respiratory symptom per day.
On their face, these results demonstrate that air pollution is not the severe health threat that EPA and the American Lung Association would have us believe. But, do they establish that air pollution caused even the effects observed?
As loyal Junk Science Home Page visitors know, relative risks on the order of 2.0 and less are typically in the noise rage of epidemiologic data. And in this case, the noise is almost as loud as the feedback produced during Jimi Hendrix's legendary guitar solos.
Thurston et al. collected data on relative humidity and pollen and found that neither was significantly correlated with adverse health effects. But according to the Merck Manual of Diagnosis and Therapy (Sixteenth Edition), changes in temperature, atmospheric pressure, dust, fumes and food preservatives may also exacerbate asthma. But the researchers did not consider any of these risk factors.
Aside from weather factors, the children engaged in crafts at camp and, conceivably, were exposed to dust and/or fumes (say from paint), either of which could have exacerbated their asthma. Organized physical exercise at camp was limited so as to avoid exercise-induced asthma. But kids away at summer camp, even asthmatic kids, are likely to engage in some form of physical activity such as simple horseplay.
Then, what about anxiety? As every asthmatic knows, asthma is easily and commonly exacerbated by anxiety. But these researchers ignored this potentially important confounding risk factor.
Imagine being a 10-year old at "asthma camp" where "the buzz" around camp is about the latest pollution readings are. Pollution levels increase. Kids get anxious. Airways constrict. Unscheduled medication use increases.
But Thurston et al. breathe easier.
Too many potential causes asthma were ignored by Thurston and his cohorts. Any observed increase in asthma cannot be attributed solely (perhaps even at all) to air pollution.
Finally, it is notable that while asthma incidence has apparently increased over the last 15 or so years, air pollution levels have been decreasing. I wonder how EPA, the Lung Association and Thurston explain that! Research recently published in Science magazine suggested that the increase in asthma in developed countries could be due to less challenged immune systems of their populations [Science 1997;275:41-42, 77-79].
In any event, don't miss The Air Pollution Experience, now on tour. Their opening song is great. Here are the lyrics of the first verse (sung to the tune of, what else, Purple Haze):
