How deep do you go when sampling soil?

How deep do you go when sampling soil?

• A. Top half-inch
• B. Six inches
• C. One foot
• D. Three inches

Answer: (A)

When assessing soil for lead exposure, you want to measure what a child is most likely to touch or ingest. The surface layer is where paint chips break off and where settled dust accumulates, making it the most relevant portion of soil for exposure risk. Sampling the top half-inch targets that accessible layer and captures the lead that children are most likely to encounter during play. Deeper soil tends to reflect historical contamination that is less likely to contribute to current exposure and can mask the true surface risk by diluting it. Therefore, the topmost half-inch is the best choice for representing the exposure potential in residential settings.

When assessing soil for lead exposure, you want to measure what a child is most likely to touch or ingest. The surface layer is where paint chips break off and where settled dust accumulates, making it the most relevant portion of soil for exposure risk. Sampling the top half-inch targets that accessible layer and captures the lead that children are most likely to encounter during play. Deeper soil tends to reflect historical contamination that is less likely to contribute to current exposure and can mask the true surface risk by diluting it. Therefore, the topmost half-inch is the best choice for representing the exposure potential in residential settings.