Why is nitrate regulated?

Why is nitrate regulated?

• A. To prevent liver or kidney problems
• B. To prevent methemoglobinemia
• C. To prevent reproductive difficulties
• D. To prevent gastrointestinal illness

Answer: (B)

Nitrate is regulated to prevent methemoglobinemia, a condition where hemoglobin is converted to methemoglobin and can no longer effectively carry oxygen to tissues. In infants, water with elevated nitrate can be converted to nitrite by bacteria in the mouth and gut; nitrite then oxidizes the iron in hemoglobin from Fe2+ to Fe3+, forming methemoglobin. With high levels, this impairs oxygen delivery and can cause serious illness or be life-threatening. Adults are less susceptible, but regulation protects vulnerable populations, especially infants. This health risk is why nitrate limits exist—the other listed issues aren’t the primary concern tied to drinking-water nitrate.

Nitrate is regulated to prevent methemoglobinemia, a condition where hemoglobin is converted to methemoglobin and can no longer effectively carry oxygen to tissues. In infants, water with elevated nitrate can be converted to nitrite by bacteria in the mouth and gut; nitrite then oxidizes the iron in hemoglobin from Fe2+ to Fe3+, forming methemoglobin. With high levels, this impairs oxygen delivery and can cause serious illness or be life-threatening. Adults are less susceptible, but regulation protects vulnerable populations, especially infants. This health risk is why nitrate limits exist—the other listed issues aren’t the primary concern tied to drinking-water nitrate.