Arsenic background concentrations in surface soils of Kavala area, Northern Greece.

A total of 65 surface (0–20 cm) soil samples were collected in an effort to estimate the arsenic background values in Kavala area, Northern Greece. Arsenic was extracted by HNO3 from the <200 µm grain size fraction, and its concentrations were determined in all samples by inductively coupled plasma–mass spectrometry. Arsenic concentrations were log-transformed, and log-normal probability plots (Q–Q plots) were generated. The geochemical background was calculated as the values that lie between g/d and g × d (g, geometric mean; d, geometric standard deviation), which are 3.5 and 25.8 mg kg−1, respectively. The baseline value (g) was 9.5 mg kg−1. With the aid of GIS software, arsenic geochemical maps of the study area were created. The majority of the arsenic elevated concentrations were found in the proximity of the industrialized zone of Kavala.