Question

What is the unit of Bio-concentration?

• A. \( ml/m³ \)
• B. \( L/cm \)
• C. \( L/kg \)
• D. \( ppm \)

Hint:

Bio-concentration units \( L/kg \) essentially tell you how many liters of environmental water contain the same amount of a substance as one kilogram of the organism's tissue.

Answer 1

The Correct Option is C

Concept: Bio-concentration refers to the accumulation of a water-borne chemical by an aquatic organism. The Bioconcentration Factor (BCF) is the standard metric used to quantify this process.

Step 1: Definition of Bioconcentration Factor (BCF).
BCF is defined as the ratio of the concentration of a chemical in an organism to its concentration in the surrounding water environment at equilibrium: \[ BCF = \frac{\text{Concentration in biota}}{\text{Concentration in water}} \]

Step 2: Analyzing units.
The concentration in the organism (biota) is typically measured in mass per unit mass (e.g., \( mg/kg \)), while the concentration in water is measured in mass per unit volume (e.g., \( mg/L \)). \[ \text{Units} = \frac{mg/kg}{mg/L} = \frac{L}{kg} \] Thus, the standard unit for bio-concentration is liters per kilogram.