Which statement best describes an advantage of composite sampling?

Which statement best describes an advantage of composite sampling?

• A. Lower cost per surface but loss of location-specific information
• B. Higher precision for every location
• C. No lab digestion required
• D. Increased sampling time

Answer: (A)

Composite sampling combines multiple surface samples into one analyzed sample, which lowers the number of analyses and, therefore, the cost per surface. This approach is advantageous when you want a broader, cost-efficient assessment across many surfaces rather than precise data for each individual spot. The trade-off is that you lose location-specific information—if one surface has a high lead value, that detail gets diluted in the composite, and you can’t tell exactly where the contamination is concentrated. That’s why this option best describes the advantage: you gain lower cost per surface and a general average across sampled surfaces, but you sacrifice the ability to pinpoint contamination to specific locations. It’s not about higher precision for every location (composites reduce precision at individual sites), and lab requirements or total time aren’t inherently defined by composite sampling in a way that would make those the primary advantage.

Composite sampling combines multiple surface samples into one analyzed sample, which lowers the number of analyses and, therefore, the cost per surface. This approach is advantageous when you want a broader, cost-efficient assessment across many surfaces rather than precise data for each individual spot. The trade-off is that you lose location-specific information—if one surface has a high lead value, that detail gets diluted in the composite, and you can’t tell exactly where the contamination is concentrated.

That’s why this option best describes the advantage: you gain lower cost per surface and a general average across sampled surfaces, but you sacrifice the ability to pinpoint contamination to specific locations. It’s not about higher precision for every location (composites reduce precision at individual sites), and lab requirements or total time aren’t inherently defined by composite sampling in a way that would make those the primary advantage.