Heavy metals and radionuclides in Islamabad's industrial area: A comprehensive analysis of soil and water pollution, source apportionment and health effects using statistical and geospatial tools

Abstract

Introduction

Heavy metal pollution in industrial areas around the world is a significant problem that is worsening day by day. Heavy and toxic metals are detrimental to human health and ecology in a region. Hence, determining their level and potential is critical to form effective pollution control strategies for reducing the risks associated with them.

Study area

Islamabad is the capital city of Pakistan with a dedicated industrial zone.

Purpose

This study evaluated the heavy metal pollution levels in the soil and water of Islamabad's industrial area and radionuclides activity in the soil using statistical, geospatial tools as well as their subsequent health and ecological hazards.

Materials and methods

Elemental analysis in this study was performed using Inductively Coupled Plasma Optical Emission Spectroscopy (ICP-OES). The radionuclides activity in the soil was quantified using High Purity Germanium Detector (HPGe).

Results

The soil of Islamabad's industrial area is highly polluted with heavy and toxic metals. The risk posed by heavy metals to the eco-system was calculated using Ecological risk factor and was found to be above recommended level. Principal component analysis (PCA), Pearson's correlation and inverse distance weighting interpolation (IDW) revealed that the soil near the steel mills, landfill and marble processing plants is extremely polluted with heavy metals. Health hazards from heavy metal exposure through ingestion, inhalation, and dermal contact were also calculated. Cr posed a carcinogenic risk to children via the three exposure pathways with the value being 4 × 10⁻⁴. Natural radioactivity levels for Ra-226, Th-232 and K-40 were found to be 25.96±12.50, 15.84±2.59, 469.48±52.38 Bqkg⁻¹, respectively. Elemental analysis of water samples coupled with geospatial analysis showed that water samples collected near the industrial complexes have elevated levels of Sb. The water quality for irrigation was assessed and the water from Islamabad's industrial area was found to be suitable for irrigation.

Conclusion

In conclusion, the soil of Islamabad's industrial area is highly polluted with heavy metals and has lower levels of natural radioactivity. The water near the industries also has elevated levels of some heavy metals.