Levels of nitrate above what concentration are known to cause blue baby syndrome?

Blue baby syndrome, or methemoglobinemia, is a condition that affects infants and is primarily caused by elevated levels of nitrates in drinking water. Nitrates can convert hemoglobin in the blood into methemoglobin, which does not effectively carry oxygen. This leads to a decrease in oxygen availability for the infant's tissues, manifesting as a blue or cyanotic appearance.

The threshold concentration for nitrates that is known to pose a significant risk for developing blue baby syndrome is set at 10 mg/l. This level has been established by health authorities, including the Environmental Protection Agency (EPA), as the maximum contaminant level for nitrates in drinking water to protect the health of vulnerable populations such as infants.

Understanding the impact of nitrates at this concentration is vital for public health and safety, particularly in areas where agricultural runoff may contribute to increased nitrate levels in water supplies. Consequently, ensuring that nitrate levels in drinking water do not exceed this limit is crucial to preventing the risks associated with blue baby syndrome in infants.