Metal bioaccumulation by barley in mesaoria plain alongside the nicosia-famagusta highway, Northern Cyprus

Mesaoria plain is mainly used for agricultural purposes and contains 50 % of the barley fields in Northern Cyprus. The construction of a highway from Nicosia to Famagusta that passes through the plain has resulted in an increasing number of vehicles from 1997 to 2006, the majority of which run on leaded gasoline. Barley is cultivated on a large scale along the Nicosia-Famagusta highway, and was tested as a possible biomonitor for heavy metals. During the vegetative period, samples of barley plants and soil were collected at 4 distances (0, 50, 100 and 500 m) from the highway, at 4 sites, from January to April 2006. The highest concentrations of Ph++ (2.82 µg g -1), Cd++" (1.52 µg g-1), Cr ++(2.86 µg g.1), Zn++(51.8 µg g -1) and Cu++(19.8 µg g-1) were recorded in soil collected beneath the highway, and the lowest in samples collected at 500 m from the highway, for Pb++ (0.54 µg g-1) in the above-ground parts of barley, Cr++ (0.85 µg g-1) in soil, and Zn++ (7.2 µg g-1) in barley plant roots. A positive relationship was found between soil and plant heavy metal concentrations. According to the EU Directive 86/278/EEC on the protection of the environment and, in particular, of the soil, concentrations of Pb44" and Zn++ are below the threshold, Cd++ are between the limits and Cr++ are above threshold.