Environmental Health

Much discussion has taken place concerning possible health hazards from exposure to anesthetic gases. In one study conducted in 1972, 525 Michigan nurse anesthetists were surveyed by mail questionnaires and telephone inter- views to determine the incidence rate of cancer group, 7 women reported having a new malignancy other than skin cancer during 1971.

6.34 Provide a 95% CI for the true incidence rate.

A comparison was made between the Michigan report and the 1969 cancer-incidence rates from the Connecticut tu- mor registry, where the expected incidence rate, based on the age distribution of the Michigan nurses, was determined to be 402.8 per 100,000 person-years.

6.35 Comment on the comparison between the observed incidence rate and the Connecticut tumor registry data.