Question

Researchers followed 2,000 individuals for 5 years to determine whether individuals exposed to high levels of arsenic in ground water were more likely to develop bladder cancer than individuals not exposed to arsenic-containing ground water. All individuals in the study were screened at the beginning of the study and found to be free of bladder cancer. This is an example of a(n)

Answer 1

The study is a cohort study which observes two groups over time to evaluate the impact of arsenic exposure in groundwater on bladder cancer risk.

Step-by-step explanation:

The study described is an example of a cohort study, which is a type of observational study where two or more groups (cohorts) are followed over time to determine how different exposures affect the incidence of a specific outcome. In this case, the researchers are observing a group of individuals over a period of five years to identify whether exposure to high levels of arsenic in groundwater increases the risk of developing bladder cancer.

This study design is critical for understanding the long-term impacts of environmental contaminants like arsenic on human health. The data generated from such studies are fundamental in establishing guidelines and policies to protect public health, as arsenic exposure not only affects bladder cancer risk but is also associated with various other cancers.