What is a Field Blank in the context of lead sampling?

In the context of lead sampling, a Field Blank serves as a control measure to ensure the integrity of the sampling process. It is essentially an unused wipe sample that is taken to the field along with the actual samples but is not subjected to any surface contact or sampling activity. The main purpose of the Field Blank is to determine if there is any contamination occurring during the sampling process itself, including potential impacts from the environment or the sampling equipment.

When conducting lead sampling, it is critical to assess whether any lead is inadvertently introduced to the samples due to handling, equipment, or environmental factors. The Field Blank helps to establish a baseline of what the contamination levels are in a controlled setting, allowing for more accurate interpretation of the actual lead levels found in the samples collected.

The other options relate to different aspects of lead sampling: testing for background contamination or securing sample integrity, but they do not directly define the role or function of a Field Blank as effectively as establishing it as an unused control sample for assessing potential contamination during sampling.