In "Booster Shots" ("Stats II, Feb. 9), you printed a brief description of our Rocketdyne cancer study. The article contains misleading information that was inappropriately interpreted, and it failed to report the major findings of our investigation.
The goal of our study was to estimate the effects of occupational exposure to ionizing radiation on the risk of dying from cancers among nuclear workers at the Rocketdyne division of Boeing North America. The article points out that the proportion of all deaths due to cancer in our worker population was approximately the same as the proportion of deaths due to cancer in the general U.S. population. Although this statement is correct, it says nothing about the possible effects of radiation on cancer mortality.
To assess these effects, we compared the rates of dying from cancers for Rocketdyne workers exposed to higher radiation doses with workers exposed to lower doses. We found that higher cumulative doses were associated with increased rates of dying from several types of cancer. The mortality rate for all cancers was about three times greater in workers exposed to the highest doses of external radiation than in workers exposed to the lowest doses.
We believe that the results of our study add to the growing body of evidence linking cancer with levels of radiation traditionally considered safe for workers. Although all studies like ours have limitations, one should not infer from our findings, as you did, that exposure to radiation in the workplace has no adverse health effects.
HAL MORGENSTERN, PhD
BEATE RITZ, MD, PhD
UCLA School of Public Health