In an attempt to catch both sides of the clean-air debate “cooking the facts,” the Reader’s Harold Henderson does a little cooking himself.

In his article “Up in the Air” [April 18], Henderson writes that air quality has improved and “these facts are inconvenient for environmentalists.” In fact, the vast majority of environmental organizations readily admit the air is cleaner. This is evidence that stronger clean-air regulations work. What has improved over time is the scientific data on human health risks from air pollution. Given the proven track record that clean-air regulations work, the EPA and environmental groups believe stronger regulations are needed to address the human health effects.

In a strange attempt to undercut the overwhelming scientific evidence on the human health implications of dirty air, Henderson writes, “It is possible that some additional studies finding no effect did not see the light of day. There’s an understandable bias among researchers, publishers, and funders in favor of work that shows something.” But wouldn’t research that finds no human health effects from air pollution be considered significant? How might that discourage researchers or publishers, and what funders might want to cover up findings that show no link between human health effects and air pollution? These questions are left unanswered.

Henderson then tries to diminish the health risks of air pollution by comparing it to other risks. First, he cites a study by the Harvard School of Public Health and the World Health Organization which looked worldwide at ten public health risks and ranked them. Malnutrition was ranked the most serious worldwide and air pollution was ranked the least dangerous. Assuming Henderson understands that the EPA clean-air regulations apply only to the United States, it is unclear why he cites this study. A similar ranking of ten risks in the US would likely rank air pollution much higher.

Then, he writes that smoking is “the deadliest air pollution.” Yes, this is true. But what does this have to do with the proposed EPA standards? Again, we are left to wonder.

Henderson compares the hazards of dirty air to taking your child to day care, where they have an increased risk of croup, bronchitis, and wheezing. First, it makes little sense to compare infectious diseases with an environmental exposure such as air pollution. Just as easily, air pollution could be compared to the risk of using a car for transportation. Of course, taking a child to day care and driving a car are risks that we understand and elect to take. In the case of air, we have no choice but to breathe.

The scientific evidence that stronger air pollution rules are needed is overwhelming. And, as Henderson points out, industry is spending millions to spread disinformation about the proposed EPA rules. But instead of clarifying this important issue, Henderson’s article further muddies the waters.

Ben Lilliston

Editorial Director Sustain

Harold Henderson replies:

I congratulate Mr. Lilliston on his careful reading of my article on fine-particulate pollution. A less attentive reader might not have focused exclusively on side issues. He might even have mentioned the main reason why the scientific case for EPA’s new fine-particle regulation is merely strong and not “overwhelming”: the risk ratio for serious illness or death from fine particles is very low, and one of the main types of confirmation epidemiologists look for in such marginal cases–physical evidence of how the particles hurt people–has so far not been found.