What is the main cause of lead contamination in drinking water?

What is the main cause of lead contamination in drinking water?

• A. Leaching from plastic pipes
• B. Atmospheric deposition
• C. Microbial activity
• D. Corrosion of lead-containing plumbing

Answer: (D)

Lead enters drinking water mainly through the corrosion of lead-containing plumbing materials, such as old service lines, lead solder, and certain brass fixtures. When water is corrosive—low in pH or alkalinity, or under aggressive oxidizing conditions—it can dissolve lead or release lead-bearing particles from these components, especially after water has been in contact with the pipes for some time. This is why controlling water chemistry and replacing lead-containing plumbing are effective ways to prevent exposure. Leaching from plastic pipes, atmospheric deposition, and microbial activity aren’t the primary pathways for lead getting into tap water in typical distribution systems.

Lead enters drinking water mainly through the corrosion of lead-containing plumbing materials, such as old service lines, lead solder, and certain brass fixtures. When water is corrosive—low in pH or alkalinity, or under aggressive oxidizing conditions—it can dissolve lead or release lead-bearing particles from these components, especially after water has been in contact with the pipes for some time. This is why controlling water chemistry and replacing lead-containing plumbing are effective ways to prevent exposure. Leaching from plastic pipes, atmospheric deposition, and microbial activity aren’t the primary pathways for lead getting into tap water in typical distribution systems.