Blue baby syndrome, or methemoglobinemia, is a disorder of the blood that can occur in babies exposed to high levels of nitrates in drinking water. The disorder that usually occurs when nitrates in the blood form chemical bonds with hemoglobin, forming methemoglobin. Methemoglobin generally can't carry adequate amounts of oxygen to the cells of the body. Babies with this syndrome typically suffer from low blood-oxygen levels, which can cause the skin of the feet, hands and face to take on a blue tint, and it can also cause vomiting, diarrhea, and, in severe cases, death. Mild cases of this condition are often treated by removing nitrate-contaminated water from the baby's diet, while more severe cases might require medication.
According to the United States Environmental Protection Agency (EPA), nitrate levels of more than ten parts per million in drinking water could be unsafe. Babies who develop blue baby syndrome are generally those who must rely on wells or other natural sources for drinking water. Nitrates often enter these sources of drinking water through surface run-off, usually from barnyards or septic systems. The EPA generally recommends that all sources of drinking water be located at least 100 feet (30.5 meters) away from septic systems, cesspools, barnyards, and other potential sources of nitrate contamination.
Babies who develop this condition may not seem terribly unhealthy. Many babies show only mild symptoms, which include blueness of the face, feet, and hands. In some babies, the face, feet, and hands may take on a purplish tint. Difficulty breathing can occur, as can vomiting and diarrhea. Methemoglobinemia doesn't typically afflict adults.
Blood taken from babies with methemoglobinemia may appear dark brown in hue, rather than bright red. Babies severely affected by the syndrome may become extremely lethargic, drool, and lose consciousness. Seizures and death are a possible outcome.
Mild cases of blue baby syndrome are often treated simply by removing contaminated water from the baby's diet. It can be incredibly difficult, time-consuming, and expensive to purify drinking water contaminated by nitrates, so most experts recommend simply finding another source of drinking water.
Removing contaminated water from the baby's diet is often all that is needed to treat this disease. Blood-oxygen levels typically begin to rise to normal within two or three days. Injections of methylene blue can increase blood hemoglobin and blood-oxygen levels in severely affected babies.