Monitoring of chromium, copper and arsenic in contaminated soils using thick-target PIXE J. Rajander a , L. Harju a, * , J.-O. Lill b , K.-E. Saarela a , A. Lindroos c , S.-J. Heselius d a Department of Analytical Chemistry,  Abo Akademi University, Biskopsgatan 8, FIN-20500  Abo, Finland b Department of Physics,  Abo Akademi University, FIN-20500  Abo, Finland c Department of Geology and Mineralogy,  Abo Akademi University, FIN-20500  Abo, Finland d Accelerator Laboratory,  Abo Akademi University, FIN-20500  Abo, Finland Abstract Soil contamination by toxic metal ions is one of the most serious environmental problems today. In this work soil samples from an area where a wood preservation plant has been active were studied. Chromium, copper and arsenic (CCA) are the main metal ions used in preservation of lumber. For the monitoring of these metal ions and of other elements in soil, thick-target PIXE (TTPIXE) has been proved to be a successful method. About 20 elements were quantitatively determined in the soil samples from the contaminated area and from a reference area. The reliability of the results was evaluated by analysing geochemical certi®ed reference materials (CRMs) of chemical compositions similar to the soil samples. Ó 1999 Elsevier Science B.V. All rights reserved. PACS: 8280.Ej Keywords: TTPIXE; Arsenic; Chromium; Copper; Contaminated soil 1. Introduction Soil contamination has become one of the greatest environmental problems in the industri- alised countries. In many places contaminated soils are a threat to the groundwater quality, and thereby to the whole biosphere [1]. In many countries e.g. Nordic countries wood preservation plants using inorganic impregnation agents such as chromium, copper and arsenic (CCA) are one of the most common soil contaminators when heavy metals are concerned. In the preservation of lum- ber, wood preservatives are used to prevent attacks from fungicides and noxious insects. The toxic eects of Cr, Cu and As to the living organisms are well known [2]. In this work soil samples from an area where a wood preservation plant was active from about 1950 to 1990 were studied. For elemental analysis of soils wet-chemical methods like atomic emission spectrometry (ICP- AES or DCP-AES), atomic absorption spectrom- etry (AAS) or inductively coupled plasma mass spectrometry (ICP-MS) are commonly used [2]. However, these methods need sample digestion or Nuclear Instruments and Methods in Physics Research B 150 (1999) 510±515 * Corresponding author. Tel.: +358-2-2154425; fax: +358-2- 2154479; e-mail: lharju@abo.® 0168-583X/99/$ ± see front matter Ó 1999 Elsevier Science B.V. All rights reserved. PII: S 0 1 6 8 - 5 8 3 X ( 9 8 ) 0 0 9 9 7 - 5