When performing wipe samples, what is the sequence of movements?

The correct answer involves performing wipe samples using a top-to-bottom and side-to-side "S" motion because this technique ensures comprehensive coverage of the surface being sampled. Starting at the top and moving downwards allows the sampler to effectively collect any lead dust or particulate matter that may settle down due to gravity. The addition of the side-to-side motion in an "S" pattern further enhances the sampling process by ensuring that a wider area is covered without missing spots, which could lead to incomplete data regarding lead contamination.

This specific movement pattern is intended to minimize cross-contamination and maximize the effectiveness of the sample collected, which is critical in accurately assessing lead risk in a given environment. By utilizing this systematic approach, the risk assessor can ensure that the samples truly represent the lead levels present across the surface being tested, leading to more reliable results in evaluating potential lead hazards.