Lead exposure in the general population of the Metropolitan Area of Barcelona: Blood levels and related factors

A cross-sectional was conducted on 254 individuals not occupationally exposed to lead to determine the degree of lead exposure in the general population of the Metropolitan Area of Barcelona. Blood lead levels (BPb) were analysed by atomic absorption spectrophotometry and zinc protoporphyrin (ZPP) by haemofluorimetry. Blood lead levels were analysed with respect to individualsʹ age, sex, area of residence, the season of the year the blood was drawn and ZPP. Mean blood lead in our series was 0.22±0.011 μmol/l (mean±S.E.); no significant differences were found with respect to area of residence, sex or season. A linear relationship was observed between BPb and individualsʹ age (BPb=0.08+0.05×age; r=0.37). The prevalence of lead intoxication (BPb>0.48 μmol/l) was 7.1%. No linear relationship was observed between BPb and ZPP. ZPP determination does not appear to be a good screening method for lead intoxication since it presents low specificity and sensitivity values with an area below the ROC curve similar to the null value line (area below the curve=0.5052, IC 95%=0.443–0.568). We conclude that lead exposure does not constitute a serious health problem in the area studied, since BPb levels found are far below the toxic limit and the prevalence of intoxication is similar to that reported in other studies conducted in other developed countries.