Environmental Protection Agency (EPA) Lead Risk Assessor Practice Exam

How many single wipe samples should ideally be collected per dwelling?

1. At least 1

2. At least 3

3. At least 6

4. At least 10

The correct answer is: At least 10

The recommendation to collect at least 10 single wipe samples per dwelling is based on the need to obtain a reliable assessment of lead dust levels within a home. This number helps ensure a more thorough evaluation of potential lead contamination in different areas, capturing variations that might occur due to factors such as usage of the space, location of lead sources, and environmental conditions. Collecting a sufficient number of wipe samples increases the likelihood of detecting lead hazards that may be present in less frequently used or often overlooked areas. By utilizing 10 samples, assessors can achieve a more representative average concentration of lead dust in the home, which is essential for accurate risk assessment and ensuring that any necessary abatement measures are properly targeted. While fewer samples may provide some indication of lead levels, they may not adequately represent the variability that can be found in larger or multi-room dwellings, potentially leading to misleading conclusions about the safety of the environment. Thus, the recommendation of collecting at least 10 wipe samples enhances the overall reliability of the lead risk assessment process.