RISK-FACTORS FOR HIGH-LEVELS OF LEAD IN BLOOD OF SCHOOLCHILDREN IN MEXICO-CITY

Risk factors associated with blood lead levels exceeding 15 mu g/dl we re analyzed in this report This relatively high lead level was selecte d because, at the time the study commenced, it was considered to be a ''safe'' level. A total of 1 583 schoolchildren were studied. The stud ents were from (a) two areas in Mexico City (Tlalnepantla and Xalostoc ) that have had historically high concentrations of lead in air; and ( b) three areas (Pedregal, Iztalpalapa, and Centro) with less impressiv e air lead levels. Parents were presented with a questionnaire that so licited information about lead risk factors. A bivariate analysis and a multilogistic analysis were conducted to identify associations and t o identify the model that most accurately explains the variability of the sample. High blood lead concentrations were found in children who lived in Xalostoc and Tlalnepantla (16.1 and 17.0 mu g/dl, respectivel y), and the lowest concentration (i.e., 10 mu g/dl) was found in child ren from Iztapalapa. The strongest association was with area of reside nce, followed by education level of parents, cooking of meals in glaze d pottery, and chewing or sucking of yellow or other colored pencils. A child's area of residence is the most significant risk factor that m ust be accounted for when any study of lead and blood lead concentrati ons is undertaken. Follow-up in similar populations should assist grea tly in the evaluation of the impact of governmental actions on public health.