Question

It has been suggested that occupational exposure to benzene in the petroleum industry increases the risk of developing leukemia. The levels of benzene to which workers in this industry have been exposed were high from 1940 to 1970, but since 1970 have been significantly reduced. What kind of study design, using petroleum workers, would provide the most useful information on whether benzene affects incidence rates of leukemia in this industry? (You may assume that records of individual worker assignments to jobs involving benzene exposure have been maintained by the industry.)

Answer 1

Answer:

Retrospective cohort.

Explanation:

The chemical substances can cause mutation in the organism's DNA. This mutation can cause different types of cancers like leukemia, sarcoma and carcinoma.

The retrospective cohort study is performed in the group in which the specific disease and its outcome is already known. This study mainly focuses on the facts that whether the individuals were earlier affected by the particular disease or not. The case given in the question represents retrospective cohort.

Thus, the answer is retrospective cohort.