At the risk of overdosing on more air pollution junk science, does air pollution cause the elderly to seek emergency hospital care for respiratory illness?
Maybe, and maybe not. Delfino et al. certainly have not shed any more light on the issue.
Delfino et al. looked at air pollution levels in Montreal, Canada and admissions to hospital emergency rooms (ERs) from June through September, 1992 and 1993.
They claim that ozone, particulate matter (PM) and sulfate levels are positively associated with respiratory visits to ERs for patients over 64 years of age. And, therefore the present findings have public health implications with regard to the adverse health effects of urban photochemical pollution on older individuals.
And of course, what air pollution study conclusion (published in an American Lung Association journal anyway) would be complete without the requisite tie to EPA's proposed air pollution standards for ozone and PM? Delfino et al. report that the ozone and PM levels observed in the study never exceeded current U.S. standards.
But (as you might expect) there's more to this conclusion than what's in the abstract.
First, Delfino et al. examined data from 1992 and 1993 separately. But they only considered the 1993 data for their conclusion. Why? For 1992, no statistically significant relationships were observed between ER visits and air pollution. They simply cherry-picked the 1993 data that supported their (pre-determined?) conclusion. The analysis of the 1992 data must have scared them off looking at any other years!
Second, analyses were performed looking at hospital admissions and air pollution levels on a same day, 1-day lag and 2-day lag bases. Statistically significant associations were only identified for the 1-day lag analysis (i.e., ER visits significantly increased only on the day after high pollution readings). Once again, Delfino et al. simply cherry-picked data that supported their conclusion, and ignored the rest.
And I couldn't wind this up without pointing out that no attempt was made to verify that the ER visits were for air pollution-induced respiratory problems. For all we know, many of the ER visits could have been associated with pre-existing pulmonary diseases, allergies, or respiratory tract infections.
The only good thing about this study is that, for a change, no U.S. tax dollars were wasted. Thanks to the Minister of Health Canada, this one's on the Canadian taxpayer.