Monitoring of heavy metal pollution in urban and rural environments across Pakistan using House crows (Corvus splendens) as bioindicator

Area of Science:

• Environmental Science
• Ecotoxicology
• Urban Ecology

Background:

• Heavy metal pollution poses risks to ecosystems and human health.
• Bioaccumulation in urban wildlife requires investigation to understand exposure levels.
• The house crow is a common urban species suitable for biomonitoring.

Purpose of the Study:

• To assess bioavailable heavy metals in urban and rural Pakistan using house crows.
• To investigate the bioaccumulation of specific heavy metals (As, Zn, Pb, Cd, Ni, Fe, Mn, Cr, Cu) in house crow feathers.
• To evaluate the house crow as a bioindicator for terrestrial pollution differences.

Main Methods:

• Collected wing feathers from 96 house crows across eight locations in Pakistan.
• Categorized locations into four groups based on geographical and environmental factors.
• Analyzed feather samples for concentrations of ten heavy metals.

Main Results:

• Significant variations in lead (Pb), nickel (Ni), manganese (Mn), copper (Cu), and chromium (Cr) concentrations were found among the groups.
• Industrial metals (Zn, Fe, Cr, Cu) were detected in both urban and rural agricultural areas.
• Urban crows showed lead (Pb) levels exceeding toxicity thresholds for birds.

Conclusions:

• The house crow is an effective bioindicator for assessing heavy metal pollution.
• Feathers can be used to differentiate local pollution levels linked to anthropogenic activities.
• This study highlights the utility of house crows in monitoring environmental contamination.