Repercussions of anthropogenic activities on soil contamination: sources, distribution, and health risks of arsenic and other non-radioactive metals in urban Bangladesh.

Abstract

In recent decades, non-radioactive metals (n-RMs) and metalloids, notably arsenic (As), have become widespread in surface soil due to human-induced activities such as industrial operations, mining, agriculture, and untreated waste disposal. To determine the accumulation of such n-RMs in the soil content, samples were collected from an industrial area in Bangladesh and analyzed using Inductively Coupled Plasma-mass Spectrometry (ICP-MS). Results indicated that the mean concentrations (mg/kg) of n-RMs followed the order of Mn (428.84 ± 61.30 mg/kg) > Zn (119.03 ± 70.04 mg/kg) > Cr (36.80 ± 8.50 mg/kg) > Ni (34.86 ± 8.05 mg/kg) > Cu (30.56 ± 4.85 kg/kg) > Co (12.12 ± 3.31 mg/kg) > Pb (9.26 ± 3.29 mg/kg) > As (7.36 ± 5.98 mg/kg) > Hg (0.22 ± 0.19 mg/kg) > Cd (0.21 ± 0.15 mg/kg). Analysis of environmental risk assessment indices yielded low to moderate contamination throughout the study area. Enrichment factor (EF) analysis for As and Zn revealed significant levels of enrichment for these two, reflecting their heightened concentrations compared to guideline values. Results from health risk analysis indices, that is hazard quotient (HQ) and hazard index (HI), demonstrated adults to be on the safer side whereas children were prone to developing cancer from long-term exposure to As. Correlation matrix, principal component analysis (PCA), and cluster analysis (CA) suggested geogenic sources for Zn, and Mn and synthetic sources for other metals. These findings attributed the presence and accumulation of n-RMs in soil to icreased human activities in the area, which in turn facilitate their uptake by plants exposing the residents of the study site to grave health impacts. The accumulation of n-RMs poses significant risks to ecosystems, including aquatic life, crops, agricultural fields, and water reservoirs.