Methemoglobin levels in children who consumed water contaminated by nitrates

Abstract

To give an importance of water quality for human consumption and its relation to health, the objective of this study was to analyze the association between nitrate levels in drinking water and the presence of target hemoglobin in children from 0 to 12 age of a small town in the county Lagunera, of Durango, Mexico. That population consumes water from two wells with different concentrations of nitrate, one of them slightly above the standard Mexican (10 mg l-1). This paper presents the preliminary data from a pilot study. The study methodology consisted in a comparative cross design in 2 groups of children between 2 and 12 years of age. The first group (exposed) consisted of 25 children and the second (control) of 19 who had lived in the area for more than a year and had taken water from the wells with concentrations 11.8 mg l-1y-1 and 4.7 mg l-1 y-1 respectively. The relationship was adjusted by gender and passive tobacco exposure. Logistic regression was used to analyze the ratio momios (MRI) as a measure of association. The results indicate that there were not significant differences between the proportion of children with detectable levels of methaemoglobin in the exposed group (32 %) and those in the control group (21 %) (p ≥ 0.05). MRI crude was 1.6 (95 % CI 0.3 to 8.1). The age of the subjects showed no association. The children had increased risk of detectable levels (OR 6.1 p < 0.05) than girls, even after adjusting for the type of well. It is possible to see the trend towards an increased risk in the exposed group despite the size of the sample. To continue with the study there will be done an adjustment of the sample size .