Atmospheric Environment 38 (2004) 5157–5168 Evidencing lead deposition at the urban scale using ‘‘short- lived’’ isotopic signatures of the source term (Pb–Zn refinery) Matthias Franssens a , Pascal Flament b, *, Karine Deboudt b , Dominique Weis a,1 , Espe´ ranza Perdrix c a De´partement Sciences de la Terre et de l’Environnement, Universite´Libre de Bruxelles, CP 160/02, B-1050 Brussels, Belgium b Universite´du Littoral - Coˆte d’Opale, UMR CNRS 8013 ‘‘ELICO’’, 32 Avenue Foch, F-62930 Wimereux, France c De´partement Chimie—Environnement, Ecole des Mines de Douai, BP 838, F-59508 Douai Cedex, France Received 7 November 2003; received in revised form 23 April 2004; accepted 5 May 2004 Abstract To demonstrate the ability of the lead isotope signature technique to evidence the spatial extent of an industrial Pb deposition plume at a local scale, dry deposition of lead in the urban environment of a Pb–Zn refinery was investigated, as a study case, using transient (‘‘short-lived’’) isotopic signatures of the industrial source. Sampling campaigns were achieved in representative weather conditions, on an 8-h basis. Dry deposition rates measured downwind from refinery emissions (E10 2 –10 3 mg Pb m 2 h 1 ), cross-sectionally in a 3–5 km radius area around the plant, represent 10–100 times the urban background dry fallout, measured upwind, as well as fallout measured near other potential sources of anthropogenic Pb. The Pb–Zn refinery isotopic signature (approx. 1.100o 206 Pb/ 207 Pbo1.135) is made identifiable, using the same set of Pb and Zn ores for 2 days before sampling and during field experiments, by agreement with the executive staff of the plant. This source signature is less radiogenic than signatures of urban background Pb aerosols (1.155o 206 Pb/ 207 Pbo1.165) and minor sources of Pb aerosols (1.147o 206 Pb/ 207 Pbo1.165). By a simple binary mixing model calculation, we established the extension of the industrial Pb deposition plume. Fifty to eighty percents of total lead settled by the dry deposition mode, 3–4 km away from the refinery, still have an industrial origin. That represents from 40 to 80 mg Pb m 2 h 1 , in an area where the blood lead level exceeds 100 mg Pb l 1 for 30% of men and 12% of women living there. We demonstrate here that stable Pb isotope analysis is able to evidence the Pb dry deposition plume in stabilised aerodynamic conditions, using a short-lived source term, suggesting that this methodology is able to furnish valuable data to validate industrial Pb aerosols dispersion models, at the urban scale. r 2004 Elsevier Ltd. All rights reserved. Keywords: Lead isotopes; Pb–Zn refinery; Urban area; Aerosol measurements; MC-ICP-MS 1. Introduction Since lead was banned from petrol, industrial emissions have become the first source of this metal in the air (Bollho¨ fer and Rosman, 2001b). On a global scale, Pb concentrations have fallen (Nriagu, 1990), but, in industrialized environments, concentrations >100 ng m 3 are still observed (Perdrix et al., 2003). Particles containing Pb are an important medium for the transfer of this metal to man (Gulson et al., 1995). Particles can be directly inhaled or ingested, after deposition on soils and transfer to the food chain, or by hand-to-mouth activity, especially for young children (Gulson et al., 1996a, b). For people living near Pb industries (mining, refining, etc.), blood-lead levels may be significant, with, often, ARTICLE IN PRESS *Corresponding author. Fax: +33-321996401. E-mail address: pascal@mren2.univ-littoral.fr (P. Flament). 1 Present address: Pacific Centre for Isotope and Geochemical Research, Department of Earth Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC, V6T-1Z4, Canada 1352-2310/$ - see front matter r 2004 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2004.05.009