Formation of non-functional methaemoglobin causes blue-baby syndrome. This is due to

Options

A. Excess of arsenic concentration in drinking water
B. Excess of nitrates in drinking water a
C. Deficiency of iron in food
D. Increased methane content in the atmosphere

Answer

### Step-by-Step Solution:

1. **Understanding Blue-Baby Syndrome**: Blue-baby syndrome, also known as methemoglobinemia, is a condition that affects infants and is characterized by a bluish discoloration of the skin due to insufficient oxygen in the blood.

2. **Identifying the Cause**: The formation of non-functional methemoglobin is the primary cause of blue-baby syndrome. Methemoglobin is a form of hemoglobin that cannot bind oxygen effectively.

3. **Sources of Nitrates**: The main source of nitrates in drinking water is agricultural runoff, particularly from the use of nitrogen-rich fertilizers. When these fertilizers are used excessively, nitrates can leach into groundwater and surface water.

4. **Impact on Infants**: Infants are particularly susceptible to the effects of nitrates because their bodies are less able to convert methemoglobin back to functional hemoglobin. When they consume water with high nitrate levels, the nitrates convert hemoglobin into methemoglobin.

5. **Consequences of Methemoglobinemia**: The presence of non-functional methemoglobin impairs the blood's ability to transport oxygen, leading to symptoms such as difficulty breathing, cyanosis (bluish skin), and in severe cases, suffocation.

6. **Conclusion**: Therefore, the formation of non-functional methemoglobin due to excess nitrates in drinking water is the cause of blue-baby syndrome.

### Final Answer:
The formation of non-functional methemoglobin causes blue-baby syndrome due to the excess of nitrates in drinking water.

---