Question

Lead pipes are not used for carrying drinking water, because

• A. They are covered with a coating of lead carbonate.
• B. They are corroded by air and moisture.
• C. Water containing dissolved air attacks lead forming soluble hydroxide.
• D. None of the above.

Answer 1

The correct option is C Water containing dissolved air attacks lead forming soluble hydroxide.

For a long time, generally up to 1960s, lead was used for some water pipes and in solder used to join copper pipes and fittings. Some types of water, particularly soft water, can dissolve lead from pipes. However, the water we supply is hard and as such is less prone to dissolution.

The amount of lead dissolved from pipes also depends on acidity, temperature and standing time of the water.

Hence, the correct answer is option C.