Which is a disadvantage of composite sampling?

Which is a disadvantage of composite sampling?

• A. Information on specific location is lost
• B. Lower cost per surface
• C. Faster laboratory processing
• D. Simpler handling procedures

Answer: (A)

Composite sampling mixes material from multiple locations into one sample to reduce the number of analyses. The key idea is that you gain efficiency and lower the total analysis effort, but you sacrifice the ability to know exactly where contamination is located. If the combined sample shows lead, you know that at least one surface contributed to the result, but you won’t know which specific surface or areas are contaminated without collecting and testing individual surfaces again. This loss of location-specific information is the main disadvantage, especially when remediation needs to be targeted. The other statements describe advantages—lower cost per surface, faster processing, and simpler handling—so they don’t represent the drawback of composite sampling.

Composite sampling mixes material from multiple locations into one sample to reduce the number of analyses. The key idea is that you gain efficiency and lower the total analysis effort, but you sacrifice the ability to know exactly where contamination is located. If the combined sample shows lead, you know that at least one surface contributed to the result, but you won’t know which specific surface or areas are contaminated without collecting and testing individual surfaces again. This loss of location-specific information is the main disadvantage, especially when remediation needs to be targeted. The other statements describe advantages—lower cost per surface, faster processing, and simpler handling—so they don’t represent the drawback of composite sampling.