Assessing blood metal levels in house sparrows (Passer domesticus) across urban and rural habitats in Meknes

Abstract

This study investigates the concentration of heavy metals lead (Pb), cadmium (Cd), and zinc (Zn) in the blood of house sparrows (Passer domesticus) across various urban habitats in Meknes, Morocco. Fifty adult sparrows were captured from five distinct sites, including industrial, high-traffic, and rural areas. Blood samples were specifically analyzed for Pb, Cd, and Zn using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). Significant variations in metal concentrations were observed across the different sites, with the highest levels found in the industrial zone: lead (Pb) at 336.02 µg/L, cadmium (Cd) at 12.28 µg/L, and zinc (Zn) at 1736.09 µg/L. Principal component analysis (PCA) and K-means clustering identified three distinct pollution clusters: Cluster 0 (high Zn, low Pb and Cd), Cluster 1 (moderate levels of all metals), and Cluster 2 (high levels of all metals). These findings emphasize the ecological and health risks posed by urban pollution, and demonstrate the value of house sparrows as effective bioindicators.