In-situ assessment of metal contamination via portable X-ray fluorescence spectroscopy: Zlatna, Romania David C. Weindorf a, * , Laura Paulette b , Titus Man c a Texas Tech University, Department of Plant and Soil Sciences, Lubbock, TX, USA b University of Agricultural Sciences and Veterinary Medicine, Department of Technical and Soil Sciences, Cluj-Napoca, Romania c Babes ¸-Bolyai University, Faculty of Geography, Cluj-Napoca, Romania article info Article history: Received 14 May 2013 Received in revised form 1 July 2013 Accepted 4 July 2013 Keywords: Metals Zlatna Spatial variability Lead Arsenic abstract Zlatna, Romania is the site of longtime mining/smelting operations which have resulted in widespread metal pollution of the entire area. Previous studies have documented the contamination using traditional methods involving soil sample collection, digestion, and quantification via inductively coupled plasma atomic emission spectroscopy or atomic absorption. However, field portable X-ray fluorescence spec- troscopy (PXRF) can accurately quantify contamination in-situ, in seconds. A PXRF spectrometer was used to scan 69 soil samples in Zlatna across multiple land use types. Each site was georeferenced with data inputted into a geographic information system for high resolution spatial interpolations. These models were laid over contemporary aerial imagery to evaluate the extent of pollution on an individual elemental basis. Pb, As, Co, Cu, and Cd exceeded governmental action limits in >50% of the sites scanned. The use of georeferenced PXRF data offers a powerful new tool for in-situ assessment of contaminated soils. Ó 2013 Elsevier Ltd. All rights reserved. 1. Introduction For hundreds of years, societal evolution has depended upon the refining and use of metals. Contemporary society depends on metals more than ever before, with many electronics reliant on upon heavy metals; generally those elements with a density of >5.0 g cm 3 . Examples of commonly used heavy metals include Hg, Pb, Cr, Cd, and As. Emissions of metals into the environment can occur via a number of different methods, with atmospheric dispersal and deposition being one of the most notable sources (Järup, 2003). Often such aerial dispersal occurs in areas of metal smelting, causing large zones of contamination even after smelting operations have ceased. Jung and Thornton (1996) noted that metals tend to accumulate in leafy portions of plants rather than fruits, with soil pH and level of soil contamination being major factors governing metal bioaccumulation in plants. Other sources of metals in the environment can include mining activities (Bech et al., 1997), vehicle emissions along roadsides (Fakayode and Olu- Owolabi, 2003; Yassoglou et al., 1997), flaking of old paint (Scott et al., 2013), products which feature wood preservatives (Gardner et al., 2013), petrochemical refining (Weindorf et al., 2012), agricultural chemicals (Modaihsh and Al-Sewailem, 1999), biosolid sludge disposal (Van Bruwaene et al., 1984; Wang et al., 2001), and natural disasters (Abel et al., 2010). To protect human health, many countries have explicit guide- lines with respect to allowable metal contents (Table 1). For example, in the USA, soils are subject to various screening limits for both industrial and residential use (Morgan, 2013). Also, the US Environmental Protection Agency (USEPA) provides guidelines for the application of sludge materials. Such guidelines feature annual pollutant loading rates, cumulative pollutant loading rates, and the maximum allowable concentration of metals in sludge (Soil Survey Staff, 2000). Romanian guidelines document normal values, alert values, and action trigger values; the latter two of which are further defined by sensitive soils and less sensitive soils (Romanian Ministry of the Forest, Waters, and Environment, 1997). In addi- tion to governmental regulations, research studies have sought to differentiate between naturally occurring geologic metals (back- ground levels), and those of anthropogenic origin (Micó et al., 2007). Justification for limiting metal content in soils lies in the litany of published studies concerning the human health effects imparted by exposure to these elements. Popescu et al. (2013) detail a number of metal exposure pathways including soil inges- tion, soil inhalation, dermal uptake, drinking water, and crop con- sumption. Metal exposure also frequently occurs through inhalation (Brevik, 2013). Once in the body, Pb exposure is linked to * Corresponding author. E-mail address: david.weindorf@ttu.edu (D.C. Weindorf). Contents lists available at SciVerse ScienceDirect Environmental Pollution journal homepage: www.elsevier.com/locate/envpol 0269-7491/$ e see front matter Ó 2013 Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.envpol.2013.07.008 Environmental Pollution 182 (2013) 92e100