New Pollution Study Doesn't Merit Rush to Regulation

By Michael Fumento

Copyright 1996 Michael Fumento

"This data makes an airtight case that we need a stronger Federal standard to control pollution."

That's what Dr. Philip Landrigan of the Mount Sinai Medical Center in New York told the New York Times about a new air emissions study.

Now, if you know anything about Landrigan, you know that to him everything makes an airtight case for a stronger federal standard to control pollution. But as they say, even a broken clock is right twice a day. Perhaps this is the good doctor's day.

The study in question, authored by C. Arden Pope of Brigham Young University and several other researchers, looked at 151 U.S. cities. It found a relationship between cities with high levels of sulfates and fine particles in the air and premature deaths in those cities.

Sulfates come primarily from coal-burning power plants and diesel exhaust, while fine particles come from a variety of sources ranging from power plants to automobile exhaust to even dust from fields. The study could have important ramifications, since the EPA appears to be working on a new standard for particulate emissions.

But the study has some serious problems, which even the authors seem willing to concede. One is that the elevations of disease, while statistically significant, are quite tiny. A high sulfate concentration was tied to an overall increase in the risk of death of 15 percent, to a 25 percent increase in cardiopulmonary disease, and to a 36 percent increase in lung cancer. Fine particles correlated to an overall increase in death of 17 percent and cardiopulmonary disease of 31 percent. The correlation to lung cancer was only three percent and statistically insignificant.

The problem is, epidemiological studies are very blunt instruments, incapable of making fine distinctions. The smaller the increase in risk, the greater likelihood that it can be entirely accounted for by some outside variable. That's why medical authorities have historically viewed increases even larger han these with great caution.

For example, a recent study found that women who had abortions had a 50 percent increased risk of breast cancer. But in a medical journal editorial accompanying the study, Lynn Rosenberg of the Boston University School of Medicine noted that even this much of an increase "is small in epidemiological terms and severely challenges our ability to distinguish whether it reflects cause and effect or whether it simply reflects bias."

Both the American Cancer Society and the National Cancer Institute also weighed in, saying the 50 percent increase just wasn't enough to really mean anything.

All of which makes it somewhat difficult to see why Pope's increases of 17 to 36 percent make for "an airtight case."

This Pope can be trusted.

In fact, they did not look at several important factors, including diet. They did control for "body mass index" (scientific terminology for how fat people are), but that results from a wide combination of dietary and exercise habits. It is no substitute for checking what people ate.

Yet for decades it has been known there is a powerful relationship between diet and cardiopulmonary disease. More recently it has also become clear that diet can affect a number of cancers, including lung cancer. One published study found that women with the highest saturated fat consumption had six times the lung cancer rate of women with the lowest level.

Climate may not have been adequately taken into account, either. Essentially when we talk about increased deaths from air pollution, we're talking about the elderly or people who were already ill with something. These people always die in much greater numbers during extremes of heat and cold. Did the Pope study account for this? Yes, but perhaps not adequately. Indeed, even now Pope is working with University of Delaware climatologist Larry Kalkstein to develop an improved method for controlling for climate.

Pope and Thun acknowledge their study's limitations, but say it needs to be seen in context of other studies connecting the pollutants in question to various health effects, including shortness of breath, respiratory symptoms, and hospitalizations from respiratory symptoms. But these may have no connection to death.

Further, the greatest claim to importance of the current study is that it is so much larger and more carefully done than those previous ones.

But the case for "regulate now, asks questions later" is even worse. Sulfates are not generally considered a risk factor for disease, and while fine particles theoretically could promote lung cancer, remember that this study found no such connection.

What's going on here? Explains Pope, "Both fine particle and sulfates are used as proxy for combustion source pollution in general."

Thus it's possible that industry and consumers could spend billions to reduce sulfates and fine particles and actually not reduce whatever was actually causing harm.

This study may prove valuable in some way, but for now hardly provides an "airtight" or any other case for massive government-mandated expenditures.

Will the EPA take all of this into account when they seek to implement new, tighter regulations? Don't hold your breath.

Read Michael Fumento's additional work on the EPA, on pollution, and on alternative fuels. Michael Fumento is the author of numerous books, including Science Under Siege.