A major health risk associated with nitrates is which of the following?

• A. cancer
• B. acute respiratory diseases
• C. blue baby syndrome
• D. reduced I.Q. in children

Answer: (C)

Nitrates in drinking water can be converted to nitrites in an infant’s body, and those nitrites oxidize the iron in hemoglobin, forming methemoglobin. Methemoglobin can’t carry oxygen effectively, so tissues don’t get enough oxygen, causing the bluish skin color known as blue baby syndrome. This is the major health risk tied to nitrate exposure in early life, which is why infants are carefully shielded from high-nitrate water when preparing formula or feeding. While nitrates have been studied for other possible effects, the best-established risk is methemoglobinemia in infants.