Weight concentration unit is which?

Weight concentration unit is which?

• A. micrograms per square foot
• B. micrograms per gram of dust
• C. milligrams per liter
• D. micrograms of lead per gram of dust (ug/g)

Answer: (D)

Weight concentration tells you how much of a contaminant is present in a given weight of material. For lead in dust, the standard unit is micrograms of lead per gram of dust (μg of lead per g of dust). This is a mass-to-mass ratio, a true weight-based concentration that lets you compare contamination across dust samples regardless of how much dust was collected. It’s not expressed per area (which would be μg/ft²) or per volume (mg/L). Saying micrograms of lead per gram of dust captures both the contaminant and the reference material, making it the precise and appropriate unit for reporting lead in dust.

Weight concentration tells you how much of a contaminant is present in a given weight of material. For lead in dust, the standard unit is micrograms of lead per gram of dust (μg of lead per g of dust). This is a mass-to-mass ratio, a true weight-based concentration that lets you compare contamination across dust samples regardless of how much dust was collected. It’s not expressed per area (which would be μg/ft²) or per volume (mg/L). Saying micrograms of lead per gram of dust captures both the contaminant and the reference material, making it the precise and appropriate unit for reporting lead in dust.