Question

Formation of non-functional methaemoglobin causes ‘Blue baby syndrome’. This is due to

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

Answer 1

The correct option is B

Excess of nitrates in drinking water

Methemoglobinemia (congenital or acquired) occurs when red blood cells (RBCs) contain methemoglobin (ferric [Fe3+] rather than ferrous [Fe2+] in haemoglobin) at levels higher than $1\%$. Methaemoglin causes less oxygen binding and prevents release of whatever oxygen is bound leading to hypoxia.