According to guidelines, how often should spiked samples or blanks be provided to the lab?

The requirement to provide spiked samples or blanks for every home sampled is based on maintaining consistency and ensuring the reliability of laboratory results. Spiked samples and blanks are critical for validating that the laboratory methods are performing accurately and to check for any potential contamination or interferences during the analysis process. By analyzing these controls with each sample from different homes, assessors can verify that results are consistent across various environments and conditions.

Regular testing of spiked samples and blanks ensures that any variability in laboratory analysis can be identified and addressed promptly. This practice is essential for risk assessment involving lead hazards, as accurate results are crucial for adequately protecting public health, especially in residential settings where children may be exposed to lead hazards. Different homes may have varied environmental conditions that could affect lead levels, hence validating each set of samples ensures the integrity of the data collected for risk assessment.