Effect of chemical composition and methods of preparation of complex oxide catalysts upon their physico-chemical and catalytic properties: Silica-zirconia catalysts

Abstract

The average blood lead concentration has significantly decreased over the last two decades among the general population. However, in Belgium, there are still high-risk populations such as groups of pregnant women who have shown elevated lead levels. The objective of this study was to evaluate the current situation of lead cord blood levels and identify sources of lead exposure by a questionnaire survey. The study was conducted in 5 maternity units in Belgium; for each, umbilical cord blood samples were collected from 50 consecutive births. At the same time a questionnaire on possible sources of lead exposure was administered to the mother. The dependant variable was a dichotomous lead level variable (<20 μg/L vs. ≥20 μg/L). The factors associated with elevated lead levels (≥20 μg/L) were mother's country of origin from south Mediterranean and from Sub-Saharan Africa, mother's educational level, using ‘tagine’ plates for cooking and using khol for make-up, but, after adjusting for potential confounding factors, only the mother's country origin from south Mediterranean (adjusted odds ratio, 5.51; 95% confidence interval [CI], 1.68–18.08; p = 0.005) and from Sub-Saharan Africa (adjusted odds ratio, 8.14; 95% CI, 2.26–29.40; p = 0.001) were significantly associated with elevated cord blood lead concentrations (≥20 μg/L). The results of this study are similar to those found by a previous study in Belgium in 2004. Sources of exposure are difficult to distinguish with this questionnaire, which might be due to other important sources of exposure that were not included in the questionnaire. Confirmation of these risk factors in future studies could lead to new prevention strategies for populations who are at risk for subsequent lead exposure.