Roanoke Times
Copyright (c) 1995, Landmark Communications, Inc.
DATE: SUNDAY, July 3, 1994 TAG: 9407030004
SECTION: NATIONAL/INTERNATIONAL PAGE: A7 EDITION: METRO
SOURCE: Associated Press
DATELINE: LENGTH: Medium
EPA based its report solely on 30 questionable epidemiological studies.
EPA: The 30 studies were merely part of the report, and it would have reached the same conclusion without them because of the "totality of evidence:" that active smoking causes cancer, secondhand smoke contains the same 40 carcinogens and there's supporting evidence from animal and genetic studies.
Of the 30 studies, only six were statistically significant.
EPA: 24 of the 30 studies showed an increase in cancer risk with exposure to secondhand smoke. Most were too small to be statistically significant, but nine were, and the probability that those nine were a fluke is less than 1 in 10,000.
None of the 11 U.S. studies found a statistically significant link between secondhand smoke and cancer.
EPA: Most of the U.S. studies were too small for statistical comparison. But eight had increased overall risks and seven that measured amount of exposure all showed risks in people who breathed the most secondhand smoke.
EPA used skewed statistics, declaring studies statistically significant when they had only a 90 percent chance of accuracy instead of the normal 95 percent chance.
EPA: Scientists use the 95 percent "confidence interval" when they're not sure if a substance will have a positive or negative effect. Because there was evidence that smoke couldn't be beneficial, 90 percent was strong enough to catch either no effect or a negative one. Upping the certainty that EPA is right another 5 percent might change one or two studies but not, it insists, the outcome.
EPA deliberately left out a major study published in November 1992 that would have changed its conclusions.
EPA: That study, published after EPA's deadline, did not find that everyone ever exposed to secondhand smoke had an increased cancer risk, but that people exposed to the highest levels, such as spouses of two-pack-a-day-smokers, were at significant risk.
EPA lumped all the small studies together to look for risk when the studies were incompatible.
EPA: The "meta-analysis" could be thrown out and the results would be the same. It was used after EPA decided there was a risk, in an effort to quantify that risk. EPA did conclude that only 3,000 lung cancer deaths a year could be attributed to secondhand smoke.
by CNB