Systematic facile study of singleton e-waste recycling site to unveil the potential bio-indicator for atmospheric heavy metals by using tree leaves

Abstract

Limited studies have been conducted with respect to atmospheric heavy metals pollution due to high cost of instruments and other associated challenges. In the present study, we have evaluated the possibility of using tree leaves as a bio-indicator of atmospheric pollution by analyzing the composition of 12 different heavy metals in leaves of six tree species and air, dust, or soil. We have chosen the four different regions of Zhejiang Province PR, China as a case study that can be employed anywhere worldwide. Among the four under consideration regions (Mukeng, Yanggongao, Wenqiaozhen, and Changyudongtian), air samples showed the highest values of total heavy metals (∑HM) 2234.28 mg/kg, while the lowest value were found in soil (17.51 mg/kg). Similar kind of heavy metal profiles were observed in the four matrices, especially for leaf and air. Cedrus deodara leaf was explored as an ideal passive sampler due to its high accumulation concentration (26.516 mg/kg) and high enrichment factor (0.93–4.02) for different heavy metals. In addition, the concentrations in Cedrus deodara leaves indicated a good value of the coefficients of correlations (r = 0.819-0.994) for Sn, Pb, Cu, Cd, As, Hg, Ni, and ∑HM in air. Furthermore, the leaf age and the lipid content could affect the accumulation of heavy metals. We strongly recommend that our current conducted research work will provide the facile, efficient along with cost-effective monitoring route for atmospheric pollution measurement with respect to heavy metals at anywhere of e-wastes recycling sites around the globe.