Using date palm (Phoenix dactylifera L.) as bio-monitors of environmental quality for exposure assessment and pollution source tracking

Abstract

The entry of potentially toxic elements (PTEs) into the environment has been raised as a problem for various countries. So, this study aimed to investigate the PTEs concentration in the environment. In this cross-sectional study, Ahvaz city, the capital city of Khuzestan province, was divided into 5 areas. At each site, three-date palms were selected. Leaves and mesh fibers samples were collected from the young palm (3 years) with a maximum trunk height of 3–4 m. Plant leaves samples were separated from the middle section of the main leaves area of the plant and mesh fibers were selected from the different parts of the palm data trunk (top, middle, and bottom of the palm data trunk on all four sides of the palm). Then, data palm samples were divided into two groups of washed/unwashed. Soil samples were collected from the closest point to the palms date at a depth of 0–50 cm including at two depths (0–20 cm and 20–40 cm), and then combined to make a composite soil sample. After the preparation of samples, PTEs were measured by ICP-OES. The highest PTEs concentrations were found in industrial and high-traffic sites and the lowest was obtained at the control site. The largest bioconcentration factor (BCF) was related to copper (2.34–7.49) in mesh fibers samples and in the leaves (1.65) in the control area. Principal component analysis (PCA) results showed metal(loid)s (copper, nickel, zinc, lead, iron, arsenic, and cobalt) are mostly related to brake wear and tire of vehicles and asphalt and road dust, while the metals (Manganese, chromium, and cadmium) mostly originate from industrial sources. Palm leaves, mesh fibers, and soil can be used as a cheap biomonitoring factor for PTEs analysis, especially in industrial and high-traffic regions.