Assessment of long-term wastewater irrigation impacts on the soil geochemical properties and the bioaccumulation of heavy metals to the agricultural products Anastasis Christou & Elena Eliadou & Costas Michael & Evroula Hapeshi & Despo Fatta-Kassinos Received: 24 October 2013 /Accepted: 18 March 2014 # Springer International Publishing Switzerland 2014 Abstract An extensive field survey was employed for assessing the impacts of long-term wastewater irrigation of forage crops and orange orchards in three suburban agricultural areas in Cyprus (areas I, II, and III), as compared to rainfed agriculture, on the soil geochemical properties and the bioaccumulation of heavy metals (Zn, Ni, Mn, Cu, Co) to the agricultural products. Both ryegrass fields and orange orchards in areas I and II were continuously wastewater irrigated for 10 years, whereas clover fields in area III for 0.5, 4, and 8 years. The results revealed that wastewater reuse for irrigation caused a slight increase in soil salinity and Cl - content in areas I and II, and a remarkable increase, having strong correlation with the period in which wastewater irriga- tion was practiced, in area III. Soil salinization in area III was due to the high electrical conductivity (EC) of the wastewater applied for irrigation, attributed to the influx of seawater to the sewage collection network in area III. In addition, the wastewater irrigation practice resulted in a slight decrease of the soil pH values in area III, while a subtle impact was identified regarding the CaCO 3 , Fe, and heavy metal content in the three areas surveyed. The heavy metal content quantified in the forage plants’ above-ground parts was below the critical levels of phytotoxicity and the maximum acceptable concentra- tion in dairy feed, whereas heavy metals quantified in orange fruit pulp were below the maximum permissible levels (MPLs). Heavy metal phytoavailability was con- fined due to soil properties (high pH and clay content), as evidenced by the calculated low transfer factor (TF). Keywords Electrical conductivity . Forage crops . Heavy metal . Orange . Public health . Wastewater irrigation Introduction Climate change and global warming effects are widely recognized during the recent decades and therefore wa- ter availability and management issues are of special significance in all arid and semi-arid regions worldwide (Hanjra and Qureshi 2010; Ostfeld et al. 2012). Water scarcity already affects every continent, and it is among the main problems to be faced by many societies and the world in the twenty-first century (March et al. 2012; UN 2013). This is particularly true in the Mediterranean areas of both southern Europe and North Africa, where water resources are limited and unequally distributed in both space and time (Milano et al. 2012). Water supply and demand imbalance in the Mediterranean region is further exacerbated by the increasing population and living standards, the development of irrigated Environ Monit Assess DOI 10.1007/s10661-014-3743-4 A. Christou (*) Agricultural Research Institute, P.O. Box 22016, 1516 Nicosia, Cyprus e-mail: anastasis.christou@ari.gov.cy E. Eliadou : C. Michael : E. Hapeshi : D. Fatta-Kassinos Department of Civil and Environmental Engineering, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus C. Michael : E. Hapeshi : D. Fatta-Kassinos NIREAS-International Water Research Center, University of Cyprus, P.O. Box 20537, 1678 Nicosia, Cyprus