Which statement about the purpose of documenting measurements for each wiped area is true?

Which statement about the purpose of documenting measurements for each wiped area is true?

• A. To speed up sample processing
• B. To document specific measurements for each area wiped
• C. To determine the lead concentration of the entire site
• D. To compute the total dust weight

Answer: (B)

Documenting the area wiped for each sample is essential because wipe results are reported as a concentration per unit area. Knowing the exact area that was wiped lets you convert the amount of lead collected on the wipe into a surface concentration (for example, micrograms per square foot or per square centimeter) and compare results across different surfaces consistently. It also provides traceability and helps identify hotspots, since you can clearly link each result to the specific area that was sampled. The other ideas don’t fit because this practice doesn’t speed up processing, it isn’t used to determine a single site-wide lead concentration, and it isn’t about computing the total dust weight. The key value is the lead per unit area, which hinges on knowing the wiped area for each sample.

Documenting the area wiped for each sample is essential because wipe results are reported as a concentration per unit area. Knowing the exact area that was wiped lets you convert the amount of lead collected on the wipe into a surface concentration (for example, micrograms per square foot or per square centimeter) and compare results across different surfaces consistently. It also provides traceability and helps identify hotspots, since you can clearly link each result to the specific area that was sampled.

The other ideas don’t fit because this practice doesn’t speed up processing, it isn’t used to determine a single site-wide lead concentration, and it isn’t about computing the total dust weight. The key value is the lead per unit area, which hinges on knowing the wiped area for each sample.