Lead toxicity depends mainly on particle solubility but not on its size. Which statement is true?

• A. True
• B. False
• C. Both
• D. Not sure

Answer: (B)

Lead toxicity is shaped by two interacting properties of particles: how soluble they are in body fluids and how small they are. Solubility determines how much lead dissolves and becomes bioavailable once it enters the body or the lungs, so more soluble forms can produce higher systemic absorption. Size controls where particles deposit and how quickly they are cleared. Very small particles can reach the deep lungs and be absorbed more readily, while larger particles tend to stay in the upper airways or be cleared before dissolving. Because both dissolution and deposition affect how much lead enters the bloodstream and reaches target tissues, you can’t focus on solubility alone. The true idea is that both solubility and particle size matter for lead’s toxic potential.