Chlorophytum comosum: A Bio-Indicator for Assessing the Accumulation of Heavy Metals Present in The Aerosol Particulate Matter (PM)

Abstract

The present research focuses on the use of Chlorophytum comosum as a bio-indicator able to accumulate, through its leaves, heavy metals present in the aerosol particulate matter (PM) in the city of Milan (Italy). For this purpose, some specimens were exposed in selected sites at the Milan University Campus for increasing periods (7, 30, 60, 128 and 165 days). The collected leaves were then analyzed to quantify Cd, Co, Cr, Cu, Mn, Ni, Pb, and Zn concentrations by inductively coupled plasma optical emission spectroscopy (ICP–OES). The leaves’ surfaces were also examined by scanning electron microscopy coupled with energy dispersion spectroscopy (SEM-EDS). Chlorophytum comosum has proved to be a good system for studying the accumulation of heavy metals. The metals present with the higher concentration were Zn and Mn followed by Cd and Cr while Co, Ni and Pb were present in lower concentration. Although the sites investigated are not very far from each other, differences in the concentration of the heavy metals analyzed were found. Furthermore, in the monitoring period considered (July 2018–December 2018) the plant was a good proxy for tracking the concentration of zinc in Milan’s PM.