title: Human exposure to thallium through tap water: A study from Valdicastello Carducci and Pietrasanta (northern Tuscany, Italy).
abstract: A geological study evidenced the presence of thallium (Tl) at concentrations of concern in groundwaters near Valdicastello Carducci (Tuscany, Italy). The source of contamination has been identified in the Tl-bearing pyrite ores occurring in the abandoned mining sites of the area. The strongly acidic internal waters flowing in the mining tunnels can reach exceptional Tl concentrations, up to 9000μg/L. In September 2014 Tl contamination was also found in the tap water distributed in the same area (from 2 to 10μg/L). On October 3, 2014 the local authorities imposed a Do Not Drink order to the population. Here we report the results of the exposure study carried out from October 2014 to October 2015, and aimed at quantifying Tl levels in 150 urine and 318 hair samples from the population of Valdicastello Carducci and Pietrasanta. Thallium was quantified by inductively coupled plasma - mass spectrometry (ICP-MS). Urine and hair were chosen as model matrices indicative of different time periods of exposure (short-term and long-term, respectively). Thallium values found in biological samples were correlated with Tl concentrations found in tap water in the living area of each citizen, and with his/her habits. Thallium concentration range found in hair and urine was 1-498ng/g (values in unexposed subjects 0.1-6ng/g) and 0.046-5.44μg/L (reference value for the European population 0.006μg/L), respectively. Results show that Tl levels in biological samples were significantly associated with residency in zones containing elevated water Tl levels. The kinetics of decay of Tl concentration in urine samples was also investigated. At the best of our knowledge, this is the first study on human contamination by Tl through water involving such a high number of samples.
authors.affiliation: C.N.R. Istituto di Chimica dei Composti Organometallici, UOS di Pisa, via Moruzzi 1, 56124 Pisa, Italy; Università di Pisa, Dipartimento di Chimica e Chimica Industriale, via Moruzzi 13, 56124 Pisa, Italy.
authors.forename: Beatrice
authors.initials: B
authors.lastname: Campanella
authors.affiliation: C.N.R. Istituto di Chimica dei Composti Organometallici, UOS di Pisa, via Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: Onor
authors.affiliation: C.N.R. Istituto di Chimica dei Composti Organometallici, UOS di Pisa, via Moruzzi 1, 56124 Pisa, Italy.
authors.forename: Alessandro
authors.initials: A
authors.lastname: D'Ulivo
authors.affiliation: Università di Pisa, Dipartimento di Scienze della Terra, via S. Maria 53, 56126 Pisa, Italy.
authors.forename: Roberto
authors.initials: R
authors.lastname: Giannecchini
authors.affiliation: Università di Pisa, Dipartimento di Scienze della Terra, via S. Maria 53, 56126 Pisa, Italy.
authors.forename: Massimo
authors.initials: M
authors.lastname: D'Orazio
authors.affiliation: Università di Pisa, Dipartimento di Scienze della Terra, via S. Maria 53, 56126 Pisa, Italy.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Petrini
authors.affiliation: C.N.R. Istituto di Chimica dei Composti Organometallici, UOS di Pisa, via Moruzzi 1, 56124 Pisa, Italy. Electronic address: bramanti@pi.iccom.cnr.it.
authors.forename: Emilia
authors.initials: E
authors.lastname: Bramanti
mesh_terms: D060766:Drinking Water / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis / Q000706:statistics & numerical data*; D004784:Environmental Monitoring; D006801:Humans; D007558:Italy; D008906:Mining; D013793:Thallium / Q000032:analysis*; D014874:Water Pollutants, Chemical / Q000032:analysis*; D014881:Water Supply / Q000706:statistics & numerical data
chemical_list: D060766:Drinking Water; D014874:Water Pollutants, Chemical; D013793:Thallium
keywords: Biomonitoring; Human contamination; Mining; Thallium; Water pollution