Contents lists available at ScienceDirect Marine Pollution Bulletin journal homepage: www.elsevier.com/locate/marpolbul Temporal evolution of the environmental quality of the Vallona Lagoon (Northern Mediterranean, Adriatic Sea) Chiara Maggi, Maria Teresa Berducci ⁎ , Bianca Di Lorenzo, Manuela Dattolo, Antonella Cozzolino, Silvia Mariotti, Valerio Fabrizi, Roberta Spaziani, Claudia Virno Lamberti Italian National Institute for Environmental Protection and Research, Rome, Italy ARTICLE INFO Keywords: Metals Sediment Biota Environmental Quality Standard Vallona lagoon ABSTRACT Guidance Document 25/2010, suggests sediment and biota are the most suitable matrices for the trend mon- itoring purpose, because they integrate the pollution over time and space. So, from 2005 to 2014, the sediment and biota concentrations of heavy metals (As, Cd, Cr, Hg, Ni, Pb) were analysed in the Vallona Lagoon (northern Adriatic Sea, Italy), widely used for intensive and extensive bivalve farming. The contamination levels in se- diment and biota were compared with Environmental Quality Standard (EQS) and threshold levels (TL) for human health. The results identified critical issues related to Cd in sediment samples as well as to Hg and Pb in biota which were not only ascribable to the physiological and seasonal variability of organisms. The Cr and Ni levels in sediment were higher than the EQS. However, the concentration increases at biota stations close to sites where EQS excesses were observed in sediment were not verified. 1. Introduction Wetland areas can be greatly affected by chemical contamination due to the long hydrologic residence time and consequent long-term retention of pollutants. This is especially acute for contamination by heavy metals, which are often present in industrial and municipal ef- fluents and are major pollutants in the industrial world causing long- term effects on marine ecosystems (Jarup, 2003; Chapman et al., 2013; Wong et al., 2015; Antizar-Ladislao et al., 2015). The European Par- liament and Council decision No. 245572001/EC identified hazardous priority substances that have to be progressively reduced or phased out from discharges; these metals include Cd, Hg, Ni and Pb (Maggi et al., 2008). According to Directive 2008/105/EC (EQS Directive), the Italian Parliament issued Legislative Decree 210 in 2010, which established the Environmental Quality Standard (EQS) for Cd, Hg, Ni, Pb (priority and hazardous substances), Cr and As in sediment from marine coastal areas, lagoons and coastal ponds (Maggi et al., 2012). For the purpose of trend monitoring, sediment and biota are the most suitable matrices, recommended by the EQS Directive because they integrate, over time and space, the pollution in a specific water body. Indeed, the changes of pollution in these compartments are not as fast as in the water column, and long-term comparisons can be made (Guidance Document n. 25, 2010; Carere et al., 2012; Maggi et al., 2012). Generally, marine pollution monitoring approaches combine examinations of chemical and biological parameters. Chemical analysis of sediments is commonly used since it reflects the spatial and temporal variation of contaminant concentrations, while analysis of tissues of filter-feeding organisms provides data on the accumulation of bioa- vailable fractions of pollutants. Heavy metals introduced into the marine environment accumulate in sediment, and thus several studies aimed at evaluating this contamination have focused on the sediment compartment that constitutes an important food source for many de- posit- and suspension- feeding animals (mussels and clams) (Guerzoni et al., 1984; Guerzoni, 1989; Fabbri et al., 2001; Liang et al., 2004; Romano et al., 2013; Diop et al., 2015). Likewise the bioaccumulation of metals in tissues of marine or- ganisms has been extensively studied in the Mediterranean Sea (Squadrone et al., 2016) and other parts of the world (Siddig et al., 2016), and bivalves are recognized as suitable organisms for biomoni- toring in marine environments (Goldberg et al., 1983; Claisse, 1989; Langston and Spence, 1995; CIESM, 2002; Carro et al., 2004; Burger, 2006; Vassiliki and Florou, 2006). These organisms also represent one of the important seafood products for human consumption, so they are studied from the environmental point of view as well as food safety (Cardellicchio et al., 2007; Cardellicchio et al., 2010; Spada et al., 2013). In particular Cd, Hg and Pb content in organisms' tissues are regulated by European legislation (EC Regulation 1881/2006) that sets maximum levels in foodstuff. http://dx.doi.org/10.1016/j.marpolbul.2017.07.046 Received 17 March 2017; Received in revised form 18 July 2017; Accepted 19 July 2017 ⁎ Corresponding author. E-mail address: mariateresa.berducci@isprambiente.it (M.T. Berducci). Marine Pollution Bulletin xxx (xxxx) xxx–xxx 0025-326X/ © 2017 Elsevier Ltd. All rights reserved. Please cite this article as: Maggi, C., Marine Pollution Bulletin (2017), http://dx.doi.org/10.1016/j.marpolbul.2017.07.046