Spatial Matrix Evaluation of Heavy Metals from Heat Ventilating Air Conditioning Filter Dust in Bonny Metropolis

Abstract

This study investigates the spatial distribution and concentration of heavy metals in dust collected from heat ventilating air conditioning (HVAC) filters in Bonny Metropolis. The importance of understanding heavy metal contamination lies in its significant health risks and environmental impact, this research is crucial for understanding environmental contamination in enclosed environments. Samples were collected from 15 coordinate points during the dry season (January- February 2024) using sterilized equipment to prevent cross-contamination. Samples were processed in the laboratory, followed by Flame Atomic Absorption Spectrophotometer (Flame AAS) analysis to quantify metal concentrations. Data analysis involved statistical methods using SPSS to determine the mean concentrations and standard deviations of the metals and environmental assessment indicators such as Pollution Load Index (PLI) and Enrichment Factor (EF). Results revealed substantial contamination with heavy metals across various sites. Lead (Pb) levels ranged from 1.40±0.01 to 8.70±0.01 mg/kg, Cadmium (Cd) from 0.001±0.00 to 0.97±0.03 mg/kg, and Chromium (Cr) from 2.04±0.04 to 9.39±0.06 mg/kg, among others. Notably, Pb and Cd levels exceeded WHO and DPR recommended values, indicating significant anthropogenic pollution sources. The contamination profiles varied by location, with specific sites showing higher multiple pollution indices, particularly for Pb, Cd, and Cr. Enrichment factors for heavy metals suggested severe enrichment due to human activities, with Pb, Cd, Cr, Cu, Ni, As, Se, Zn, and Hg significantly elevated at most sites. These findings highlight severe environmental and public health risks, emphasizing the need for urgent remediation and regulatory measures, for improved waste management practices and public awareness of the dangers of heavy metal pollution. Regular maintenance and replacement of HVAC filters, as well as minimizing indoor activities that generate heavy metal-laden dust, are recommended to mitigate exposure. Future research should focus on identifying specific anthropogenic sources and developing effective strategies for mitigating heavy metal pollution in urban environments. The study underscores the importance of continuous monitoring and stricter environmental controls to safeguard public health and environmental air quality in Bonny Metropolis.