What percent of hairs and fibers are lost within the first 8 hours following deposition?

• A. 50%
• B. 100%
• C. 10%
• D. 90%

Answer: (D)

The key idea is how quickly trace materials can disappear after they’re deposited. Most hairs and fibers are not firmly fixed and can be removed or displaced by normal activity, handling, and environmental factors. Within the first eight hours, about 90% of these hairs and fibers are lost from the original surface. This rapid drop happens because shedding, friction, air movement, and routine cleaning or brushing routinely remove or transfer a large portion of the material very soon after deposition. That’s why the window for collecting hairs and fibers is so important—the majority will already be gone after eight hours, making timely recovery crucial. The other percentages would imply unrealistically different persistence rates, whereas 90% aligns with the observed rapid early loss.