Assessing Heavy Metals Accumulation for Sustainable Urban Air Quality Using Tree Foliage as Bio-indicator

Abstract

Rapid urbanization together with industrial activities have caused environmental pollution to increase substantially through heavy metal pollutant accumulation that creates dangers for both ecosystem and human health. This research analyses heavy metal accumulation trends of lead (Pb), copper (Cu), chromium (Cr), and cadmium (Cd) in tree foliage obtained from three different urban sites around Lahore Pakistan specifically Punjab University, Quaid-e-Azam Industrial Estate, and Canal Road. Scientists selected three tree varieties namely Eucalyptus camaldulensis along with Prosopis juliflora and Azadirachta indica to determine their capacity as bioindicators of heavy metal pollution. Researchers collected leaf samples from various multiple trees across sites while using systematic methods to obtain proper representation. The scientific procedure entailed acid digestion followed by atomic absorption spectrophotometry to measure the metal concentrations in the collected foliage. The quantitative studies showed variations in metal concentrations within and between the chosen species at their different locations. P. Juliflora collected from the industrial site accumulated the highest amount of Pb among all heavy metals while exhibiting a concentration of 9.653 mg/kg. A. indica along with E. camaldulensis demonstrated strong accumulation levels of Cr, Cu, and Cd as the distribution numbers changed between plant species and sample sites. Tree foliage contamination by heavy metals indicates continuous atmospheric pollution which leads to hazardous environmental and health risks. The heavy metal sequestration ability of these tree species functions as a natural way to detect pollution and demonstrates the immediate necessity for pollution mitigation methods. More studies need to identify contamination sources while evaluating the ability of plants to cleanse environments because they provide a baseline for sustainable urban ecosystem development.