Current sources of lead exposure and their relative contributions to the blood lead levels in the general adult population of Northern France: The IMEPOGE Study, 2008-2010.

There is justification for limiting lead (Pb) exposure as much as possible, given its impact on health at low concentrations. Consequently, the aim of this study was to measure blood lead levels (BLL) and examine exposure factors related to BLL variations in the general adult population of northern France, a current and past industrial area. Two thousand inhabitants of northern France, aged between 20 and 59 years, were recruited using the quota method with caution. Blood lead levels were quantified by inductively coupled plasma-mass spectroscopy (ICP-MS), and variation factors were studied separately in men and women using multivariate stepwise linear and logistic regression models. The geometric mean of the BLL was 18.8 µg/L (95% confidence interval [CI]: 18.3-19.3). Occupational factors affected BLL only in men and represented 14% of total explained variance of BLL. External occupational factors significantly increasing mean levels of BLL were tobacco, consumption of some beverages (wine, coffee, tea, and/or tap water), raw vegetables, housing characteristics (built prior to 1948, Pb piping in the home) and do-it-yourself or leisure activities (paint stripping or rifle shooting). Consumption habits accounted together for 25% and 18% of the total explained variance, respectively, in men and women. Industrial environment did not significantly contribute to BLL variations. Blood lead levels observed in the general population of this industrial part of France did not appear to be excessively elevated compared to values found internationally. Nonetheless, these BLL remain a public health issue in regard to nonthreshold toxicity attributed to Pb.

Influence of delta-aminolevulinic acid dehydratase gene polymorphism on selected lead exposure biomarkers in a cohort of ex-smelter workers.

Lead (Pb) body burden and toxicity may be influenced by genetic polymorphisms. The aim of this study was to investigate the influence of G177C delta-aminolevulinic acid dehydratase (ALAD) polymorphism (rs1800435) on selected Pb exposure biomarkers in a population of workers highly exposed to this metal in the past. A cross-sectional survey was conducted between 2007 and 2009 within the cohort of ex-employees of a smelter in the north of France that closed down in 2003. A questionnaire was completed by each participant and blood samples enabled determination of Pb levels and ALAD polymorphism. Five parameters estimating the Pb body burden and its variations were studied: last blood lead level (BLL) during activity, cumulative blood Pb index, BLL at the time of the study, and absolute and percent changes in BLL after cessation of metal exposure. Multiple regression models were used to evaluate links between ALAD polymorphism and the selected Pb exposure biomarkers. Two hundred and four men were included. At the time of inclusion, the median age was 53.5 yr. The median duration of Pb exposure was 25 yr and the median latency since end of exposure was 5.6 yr. The frequency of ALAD-2 allele was 9.3%, with 34 subjects being heterozygous (ALAD1-2) and 2 homozygous (ALAD2-2). According to genotype, there was no significant difference for any of the five selected Pb exposure biomarkers. These results lend support to the notion that ALAD polymorphism exerts no marked impact on Pb body burden.