Final answer:
Lead is the indoor air pollutant linked to anemia and health impairments in the mentioned scenario. It poses a risk from hobbies involving lead-based products or the use of leaded materials in the home.
Step-by-step explanation:
The indoor air pollutant causing the problem of anemia and impaired mental and physical health in the family who decided to buy clay glasses is lead. Lead is a toxic metal that can cause serious health issues, especially in children, such as developmental problems, cognitive deficits, and other physical problems. Indoor environments can be contaminated with lead through several routes, including hobbies that involve working with lead-based products or the use of leaded paints and substances. It is important to be aware of the potential sources of lead exposure in the home to prevent such health issues.