Methaemoglobin levels in infants receiving low dietary nitrates in eastern Nigeria

Methaemoglobin levels in 154 normal infants from Aba, Imo State, Eastern Nigeria were determined. In the population 53% showed methaemoglobin levels 0–2%, 32% showed 3–8% and 15% showed 9‐23%. The nitrate levels in the tap waters, boreholes and rivers ranged between 1.10–48.4 mg/1 with a mean of 10.20 mg/1. The breast milk showed 0.5–40.6 mg/1 with a mean of 18.1 mg/1 and the commercial milk formulae and a local food prepared from maize (pap) showed a range of 87.1–700 mg/lOOOg with a mean of 360mg/1000g on dry basis. There was no significant association between the high methaemoglobin levels in the blood and the levels of nitrates they ingested. A more intensive data collection is recommended in view of the increasing threat of nitrates in the waters from indiscriminate disposal of wastes and agricultural runoffs.