Environmental Protection Agency (EPA) Lead Risk Assessor Practice Exam

What is the minimum number of dwellings to sample in a multi-family building with only 4 units using the targeted/worst-case approach?

1. 2 units

2. 4 units

3. 10 units

4. All units

The correct answer is: All units

In the context of the targeted or worst-case sampling approach in a multi-family building, particularly one with only four units, sampling all units is crucial to gaining a comprehensive understanding of lead exposure potential within that specific environment. This methodology is often implemented in recognition that lead hazards can vary spatially and may exist in different units due to various factors, such as maintenance practices, resident behaviors, and the age of the buildings. Sampling every unit ensures that any lead contamination present, whether from chipping paint, dust, or other sources, is adequately identified. This is particularly important in situations where the units share common walls or features that may influence the distribution of lead hazards. By assessing all four units, lead risk assessors can effectively evaluate the overall risk and recommend appropriate remediation measures if necessary. In contrast, only sampling a subset of the units—even if it might seem sufficient—could potentially miss important lead hazards that could exist in untested areas, leading to incomplete data and possibly inadequate risk management decisions. This is why the correct approach in this scenario is to sample all units.