Blue baby syndrome is caused bya) Nitrate pollution of surface water b) Nitrate pollution of ground waterc) Sulphate pollution of surface water d) Sulphate pollution of ground wate

Blue baby syndrome is caused by b) Nitrate pollution of ground water.

Here's a step-by-step explanation:

1. Blue baby syndrome, also known as methemoglobinemia, is a condition that occurs primarily in infants. It causes a blue or purple tint to the skin, hence the name.

2. This condition is caused by an excess level of methemoglobin, a form of hemoglobin that is unable to carry oxygen, in the baby's blood.

3. One of the main causes of this condition is the consumption of water that is high in nitrates.

4. Nitrates are often found in high levels in ground water, especially in rural areas where agricultural fertilizers, which are high in nitrates, are used extensively.

5. When infants consume this nitrate-rich water, their bodies convert the nitrates into nitrites.

6. These nitrites then react with the hemoglobin in their blood to form methemoglobin, leading to the symptoms of blue baby syndrome.

7. Therefore, the correct answer is b) Nitrate pollution of ground water.