Heavy metal contamination in wild avian species inhabiting human-modified habitats

Health of birds and heavy metal toxicity are growing concerns in Pakistan because of irresponsible industrial waste management and farming practices. Eight species of common wild birds were studied from three different study sites which varied in the type of environmental pollution (Kasur: industrial waste, Lahore city: traffic pollution and Shahdara: mixed pollution of traffic, sewerage, and industry which the Ravi River accumulates). Heavy metal analysis of six heavy metals in the various organs of birds showed that there was no evidence of organ preference for metal accumulation in birds. Shahdara and Kasur with numerous industries both showed chromium concentrations above toxicity levels in 54.16% tissues of Granivorous birds, 60% of omnivorous birds, and 33.33% in tissues of carnivorous species. Statistical analysis proved that there is no correlation between weight of birds and accumulation of metals; it depends on food preference of birds and properties of the metals as bioaccumulators or biomagnifiers.