What is a potential health effect of nitrate exposure in infants?

Nitrate exposure in infants can lead to methemoglobinemia, commonly referred to as "blue baby syndrome." This condition occurs when nitrates are converted into nitrites in the body, which then impair the ability of red blood cells to carry oxygen. Infants, particularly those less than six months old, are at greater risk because their digestive systems are less mature, making them more vulnerable to the effects of nitrates. When the level of methemoglobin in the blood increases beyond a safe threshold, it can lead to symptoms such as difficulty breathing, cyanosis (a blue tint to the skin), and in severe cases, it can be life-threatening.

Understanding the potential health effects of nitrate exposure is crucial for water operators, particularly in areas where nitrate levels might exceed safety standards, ensuring that measures are taken to protect vulnerable populations, especially infants. The other options listed do not specifically represent the critical and significant health impact that nitrates have on infants, highlighting why methemoglobinemia is the key concern in this context.