Environmental exposure to lead in a population of adults living in northern France: lead burden levels and their determinants

As part of the assessment of a site in northern France polluted by metals f rom two smelters (in particular, lead, cadmium and mercury), a cross-sectio nal study was carried out which intended to estimate the levels of the lead burden of the adult population living on the site and the factors associat ed with these levels. The exposed zone included 10 municipalities in the No rd-Pas de Calais region, located in the vicinity of two non-ferrous metal s melters. The soils in these municipalities contained between 100 and 1700 p pm of lead. The non-polluted zone contained 20 municipalities from the same region, drawn randomly from those in the region of comparable size but fre e from any industrial lead exposure. The adult study population (301 men an d 300 women) was stratified according to age, sex, employment status and ex posure level. The inclusion criteria required subjects who were aged betwee n 20 and 50 years and had been living in the exposed zone for at least 8 ye ars; the exclusion criteria were pregnancy, cancer, kidney disease and diab etes. No more than 10% of the subjects participating could work at one of t he two smelters. Data collection took place at home; visiting nurses interv iewed subjects to complete a questionnaire and also took blood samples. The lead assay was performed by atomic absorption spectrometry. The geometric mean of the blood-lead levels was 74 mug/l, 95% CI = 69-80 among men and 49 mug/l, 95% CI = 46-53 among women. Blood-lead levels exceeding 100 mug/l w ere found among 30% of men and 12% of women. Several factors were associate d with variation Of the mean blood-lead level: the blood-lead level was sig nificantly higher among the men for subjects living less than 1 km from the smelters (geometric mean x 1.3, 95% CI = 1.1-1.6), for those who drink alc oholic beverages (x 1.1, 95% CI=1.0-1.2 for consumption of 30 g/day), those who smoke (x 1.2, 95% CI = 1.0-1.3 for 20 cigarettes/day), and for subject s with occupational exposure; among the women, for subjects living less tha n 1 km from the smelters (geometric mean x 1.5, 95% CI = 1.2-1.7), for thos e who drink alcohol (x 1.1, 95% CI = 1.1-1.2 for a daily consumption of 10 g), and for women living in a building constructed before 1948 (x 1.2, 95% CI=1.0-1.4). (C) 2001 Elsevier Science B.V. All rights reserved.