2.14. A study is planned to study whether passive smoking (being exposed to secondhand cigarette smoke on a regular basis) leads to higher rates of lung cancer.

(a) One possible study is to take a sample of children, randomly select half of them for placement in an environment where they are passive smokers, and place the other half in an environment where they are not exposed to smoke. Then 60 years later the observation is whether each has developed lung cancer.

Would this study be an experimental study or an observational study? Why?

(b) For many reasons, including time and ethics, it is not possible to conduct the study in (a).

Describe a way that is possible, and indicate whether it would be an experimental or observational study.