Explanation:

Excessive nitrates in drinking water can cause the blue baby syndrome. When it enters in an infant’s body it gets converted into nitrite in its digestive system. It then reacts with the haemoglobin present in the blood with together forms methaemoglobin, which cannot carry oxygen, thus organs may deprive of oxygen. As a result, thinskinned areas like lips, earlobes develop a bluish colour. It may also cause respiratory and digestive problems in adults.