Human exposure to mercury in the vicinity of chlor-alkali plant Darija Gibic ˇar a , Milena Horvat a,Ã , Martina Logar a , Vesna Fajon a , Ingrid Falnoga a , Romano Ferrara b , Enrica Lanzillotta b , Claudia Ceccarini b , Barbara Mazzolai c , Bruce Denby d , Jozef Pacyna d,e a Jozef Stefan Institute, Department of Environmental Sciences, Jamova cesta 39, 1000 Ljubljana, Slovenia b Institute of Biofisics Area della Ricerca, Pisa, Italy c Scuola Superiore Sant’Anna, CRIM Laboratory, Pisa, Italy d Norwegian Institute for Air Research, PO Box 100, No-2027 Kjeller, Norway e Faculty of Chemistry, Gdansk University of Technology,11/12 G. Narutowicza Str., 80-952 Gdansk, Poland article info Article history: Received 23 July 2008 Received in revised form 1 January 2009 Accepted 23 January 2009 Available online 14 March 2009 Keywords: Chlor-alkali plant Human exposure Mercury Methylmercury Selenium Vegetable Fish Air abstract The main objectives of our study were to estimate the impact of a mercury cell chlor-alkali (MCCA) complex in Rosignano Solvay (Tuscany, Italy) on the local environment and to assess mercury exposure of inhabitants living near the plant. Measurement campaigns of atmospheric Hg near the MCCA plant showed that the impact of the emitted Hg from the industry on the terrestrial environment is restricted to a close surrounding area. Total gaseous mercury concentrations in ambient air of inhabited area around the MCCA plant were in the range of 8.0–8.7 ng/m 3 in summer and 2.8–4.2 ng/m 3 in winter. Peaks of up to 100 ng/m 3 were observed at particular meteorological conditions. Background levels of 2 ng/m 3 were reached within a radius of 3 km from the plant. Reactive gaseous mercury emissions from the plant constituted around 4.2% of total gaseous mercury and total particulate mercury emission constituted around 1.0% of total gaseous mercury emitted. Analysis of local vegetables and soil samples showed relatively low concentrations of total mercury (30.1–2919 mg Hg/kg DW in the soil; o0.05–111 mg Hg/kg DW in vegetables) and methylmercury (0.02–3.88 mgHg/kg DW in the soil; 0.03–1.18 mg Hg/kg DW in vegetables). Locally caught marine fish and fresh marine fish from the local market had concentrations of total Hg from 0.049 to 2.48 mgHg/g FW, of which 37–100% were in the form of methylmercury.19% of analysed fish exceeded 1.0 mg Hg/g FW level, which is a limit set by the European Union law on Hg concentrations in edible marine species for tuna, swordfish and shark, while 39% of analysed fish exceeded the limit of 0.5 mg Hg/g FW set for all other edible marine species. Risk assessment performed by calculating ratio of probable daily intake (PDI) and provisional tolerable daily intake (PTDI) for mercury species for various exposure pathways showed no risks to human health for elemental and inorganic mercury, except for some individuals with higher number of amalgam fillings, while PDI/PTDI ratio for methylmercury and total mercury exceeded the toxicologically tolerable value due to the potential consumption of contaminated marine fish. & 2009 Elsevier Inc. All rights reserved. 0. Introduction Mercury is a naturally occurring element in the Earth’s crust. Over geological time, it has been distributed throughout the environment by natural processes, such as volcanic activity, fires, movement of rivers, lakes, and streams, oceanic up-welling, and biological processes. Since the advent of humans, and particularly since the industrial revolution of the late 18th and 19th centuries, anthropogenic sources have become a significant contributor to the environmental distribution of mercury and its compounds (WHO, 2003). Major human sources of mercury involve coal combustion in power plants, the production of caustic soda with the use of the Hg cell process, and cement production (Pacyna et al., 2006). Although the mercury cell chlor-alkali (MCCA) technique is in many places being replaced by alternative techniques, it is still the most commonly used in Europe. More recent estimates report emissions from the chlor-alkali industry to be responsible for about 17% or 40.4ton/yr of anthropogenic total mercury emissions (Pacyna et al., 2006). In Tuscany, Italy, mercury is present in the environment as a product of natural and anthropogenic sources. The cinnabar (HgS) deposits of Mt. Amiata are a major source of Hg in the central part of Tuscany. Mercury mining and smelting activities in this area were present as early as the Etruscan period (8th–1st centuries B.C.) and ceased in 1980. In this area high mercury levels were found in soil, vegetation, air (Bargagli et al., 1987; Barghigiani and Bauleo, 1992; Ferrara et al., 1992), farm produce (Barghigiani and Ristori, 1994) and fish (Barghigiani et al., 1991; Barghigiani and De Ranieri, 1992; Rossi et al., 1993; Barghigiani et al., 2000; Scerbo et al., 2005). Additional sources of mercury contamination in this ARTICLE IN PRESS Contents lists available at ScienceDirect journal homepage: www.elsevier.com/locate/envres Environmental Research 0013-9351/$ -see front matter & 2009 Elsevier Inc. All rights reserved. doi:10.1016/j.envres.2009.01.008 Ã Corresponding author. Fax:+386 15885346. E-mail address: milena.horvat@ijs.si (M. Horvat). Environmental Research 109 (2009) 355–367