Water Quality Parameters MCQ with answer and solution

Concept

Health effects of nitrate impurities in water

Formula

NONE

Step-by-step solution

1. Excessive nitrate concentration in drinking water reacts with hemoglobin in infants to form methemoglobin. 2. Methemoglobin impairs the oxygen-carrying capacity of blood, leading to cyanosis. 3. This condition is commonly known as methemoglobinemia or blue baby syndrome. Answer: A

Explanation

Excess nitrates in drinking water convert into nitrites inside an infant's digestive system, which react with hemoglobin to form methemoglobin. This compound reduces the oxygen-carrying capacity of blood, leading to a blue tint on the baby's skin known as methemoglobinemia or blue baby syndrome.

Why the other options are wrong

B) Corrosiveness is primarily caused by low pH or elevated carbon dioxide and chloride levels in water. C) Toxic effects on the heart and nerves are caused by heavy metals like lead, arsenic, or mercury. D) Dental fluorosis is caused by excessive fluoride concentrations in drinking water.

Shortcut

Nitrates cause Methaemoglobinaemia, commonly known as Blue Baby Syndrome.

Common mistake

Confusing the effect of nitrates with fluorides or heavy metal toxicities in water.