Cypress Tree (Cupressus arizonica Greene.) as a Biomonitor of Heavy Metal Pollution in the Atmosphere of Isfahan

Cypress tree with blue green foliage and scaly reddish brown bark is planted throughout world as an ornamental plant. One of the newest ways for determining amount and kind of environmental pollutants is natural biomonitoring. The samples were obtained from three sites (heavy traffic, moderate traffic and control) in Isfahan during August-September and November-December 2013 and February-March 2014. The concentrations of Zn, Ni and Cu in leaf and root were measured by using a flame atomic absorption spectrophotometer. Variations in the studied traits between sites and seasons were observed due to different anthropogenic activities. The higher concentration of the studied heavy metals in leaves rather than in roots in all locations illustrated a contribution of significant atmospheric deposition. The results of correlation coefficients between traits indicated that the sites were influenced by a different source of pollution. There was a positive correlation between zinc and copper, indicating that they could be originated from fuels as well as powder of shoe brake of vehicles. The mean metal concentration values were arranged in the following order: Zn > Cu > Ni. The level of zinc in leaf and root was moderate at the control site indicating that vehicle traffic is a minor emission source for zinc and there may be another zinc source around there, such as industrial activities. The results demonstrated the suitability of the cypress (Cupressus arizonica Greene.) tree as a biomonitorof atmospheric pollution in Isfahan.