Sociodemographic determinants and temporal variability of blood lead levels (2003-2019) in a pooled analysis of nine studies in four European countries.

Despite regulatory actions, lead (Pb) exposure remains a major environmental health concern worldwide due to its widespread occurrence and potential adverse effects. The aims of this study were to explore internal Pb exposure in EU citizens, identify its main sociodemographic determinants, and investigate temporal variations over the last decades. Blood Pb data from a total of 17,790 individuals from 9 biomonitoring studies conducted between 2003 and 2019 in four European countries [Belgium (FLEHS I-IV), teenagers and adults; Czech Republic (SZU), children and adults; Spain (BIOAMBIENT.ES), adults; Germany (ESB, GerES IV and V), with all three age groups] were used. The European Human Biomonitoring Initiative (HBM4EU) harmonized and integrated the different datasets. Linear mixed-model analyses were performed to explore exposure determinants related to Pb concentrations. All participants showed detectable blood Pb concentrations, with an overall mean concentration (± standard deviation) of 20.6 (± 16.7) µg/L. In multivariable analyses, older age at recruitment, smoking habit and residence in more urbanized areas were associated with higher Pb levels, whereas more recent sampling year and higher educational level with lower concentrations. After pooled analysis of individual data, no significant differences were found in the Pb levels of the European citizens studied, probably due to the heterogeneity of the studies included. Collaborative efforts between public health agencies, environmental regulators and communities must continue to monitor trends, explore emerging sources of exposure and refine strategies to ensure sustained progress in reducing Pb levels and protecting the health of European population.