Describe the three levels of prevention in environmental health and provide an example of each.

• A. Primary prevention reduces exposure before health effects occur; Example: lead-based paint abatement.
• B. Secondary prevention reduces exposure before health effects occur; Example: lead abatement program.
• C. Tertiary prevention reduces disease occurrence; Example: vaccination program.
• D. Primary prevention reduces disease burden after onset; Example: rehabilitation after toxin exposure.

Answer: (A)

Prevention in environmental health is organized by timing relative to disease: stopping it before it happens, catching it early to prevent further harm, and reducing harm once disease or injury has already occurred.

The statement that primary prevention reduces exposure before health effects occur is the best fit because it directly targets eliminating or lowering risk before any disease or injury can arise. Lead-based paint abatement is a classic example: by removing lead hazards, you prevent lead exposure and the subsequent health problems in children.

Secondary prevention is about finding disease early to prevent progression or complications, often through screening or early monitoring. The idea that this level reduces exposure before health effects occur mixes up two different aims—early detection vs. exposure prevention.

Tertiary prevention focuses on reducing damage or disability once disease or injury has already occurred, such as rehabilitation after toxin exposure. Vaccination, while highly effective at preventing disease, actually serves as primary prevention because it prevents the disease from occurring in the first place.

So the correct concept aligns with primary prevention reducing exposure before health effects, with lead abatement as the example.