A Treatment of the EPA ETS Report


Posted 1/5/96

THE "CRS REPORT"

The "CRS Report" issued on November 14, 1995 is being represented by the tobacco industry and its allies as discrediting the EPA report on passive smoking and lung cancer. This is simply not true; the CRS report actually AGREES with the EPA. The operative statement in the report (on page CRS-2) says:

"Calculations based on data from the Fontham et al study [the largest, best study of passive smoking and lung cancer, published after the EPA report was completed in 1992] and assuming an average exposure for the entire population at risk (a no-threshold model) result in a range of 470 to 5500 annual lung cancer deaths in the U.S. from ETS with a mean value of 2780. This compares to a mean value of 3300 calculated by the EPA under the same assumption. Data from the Brownson et al study, on the other hand, produce no annual lung cancer deaths from ETS under the no-threshold assumption. If a threshold model is used to simulate the upper limit of a possible upward dose response behavior, the mean number of lung cancer deaths is 440 calculated from the Fontham et al data and 530 for the Brownson et al data. Over 70 percent of these deaths calculated in the no-threshold example and all those calculated in the threshold model occur to individuals who are exposed to both spousal and background ETS. The remaining deaths in the no-threshold model would result from exposure only to background ETS."

Given the uncertainties in computing these estimates, there is no practical difference between 2780 and 3300.

It is also important to stress that there is no evidence that there is a threshold for cancer induced by secondhand smoke. The CRS admits that their use of a threshold model is purely speculative (on page CRS-50):

"It is important to point out that the threshold illustration is a hypothetical example and does NOT mean that any lung cancer which might result from ETS exposure would actually exhibit a threshold dose response relationship. While data from some studies have shown such a behavior as seen in the previous chapter, the statistical power of those studies is too weak to conclude that such a behavior exists. The use of a threshold model in these calculations is only to simulate the upper limit of a possible upward dose response behavior in order to bracket the range of consequences of possible dose response relationships. Finally, even if a threshold model were approximately correct, public health officials may still choose to use a model closer to the no-threshold approach in order to build in ensure [sic] that all populations are protected."

The CRS recognizes that the EPA report has received wide support from the scientific community and that all the criticism is coming from the tobacco industry (on page CRS-6):

"The EPA report received widespread support from the public health community and from the larger scientific community. But it has been criticized by tobacco industry researchers and scientific consultants. A few independent statisticians and epidemiologists have also raised objections to EPA's statistical analysis of the ETS epidemiologic studies."

All the "independent" statisticians and epidemiologists that critical of the EPA that I have seen have ended up having financial ties to the tobacco industry (often quietly).

It is also important to emphasize that the CRS took a very narrow view of the issue of ETS and lung cancer and simply looked at the studies published since the EPA report was issued. It would have been better to provide a review of ALL the data.

The bottom line: despite the weakness of the approach in the CRS report, it reaches essentially the same conclusions as the EPA and is certainly not a repudiation of the EPA.

The reference for the complete report is: Environmental Tobacco Smoke and Lung Cancer Risk: CRS Report to Congress. C. S. Redhead and R.E. Rowberg. Washington DC: Congressional Research Service, Library of Congress. Report 95-1115 SPR. November 14, 1995.

A postscript: This is not the first time that the tobacco industry has misrepresented scientific reports as part of an effort to discredit another scientific report. In 1986, the US Surgeon General published "The Health Effects of Involuntary Smoking" that concluded that ETS caused lung cancer, was bad for kids, and that simply separating smokers and nonsmokers would "reduce, but not eliminate" the risks of passive smoking. About 6 weeks later, the National Academy of Sciences produced its "Environmental Tobacco Smoke" report, which concluded the same things. Even so, the tobacco industry loudly claimed that the NAS report discredited the Surgeon General.

There is another point to keep in mind here: The EPA report, while very important, was NOT the first time that major scientific bodies concluded that ETS caused cancer. The Surgeon General and NAS reached this conclusion a decade ago. Viewed in this context, the CRS report is another tempest in a teapot being stirred up by the tobacco industry on hot air.

************
Prepared by Stanton A. Glantz, PhD, Professor of Medicine, University of California, San Francisco. Material may be freely used. (Dr. Glantz would appreciate a copy of any materials prepared with this material.


************

EPA/600/6-90/006F Released January 7, 1993

You may read the EPA Report's summary/conclusions at:
Ash's page

To receive a free copy of the entire report, write to:
EPA
26 West Martin Luther King Dr.,
Cincinnati, Ohio, 45268

or call (513)569-7562, or
fax (513)569-7566.


************
Go To: Tobacco BBS HomePage / Resources Page / Health Page / Documents Page / Culture Page / Activism Page
***********************
Return to Communications from the Front
***********************

END OF DOCUMENT