Analysis of the levels of metal(loid)s in environmental compartments in Ireland towards a screening measure for potential relative risk using open-source datasets

Abstract

Several metals and metalloids (metal(loid)s) have been identified as potential pollutants. Naturally occurring background levels and anthropogenic sources (direct or indirect) contribute to the baseline concentration of metal(loid)s in the environment. Recorded metal(loid)s in various environmental media (soil, water, sediment) were evaluated from existing databases. The first database is the national soil database or Soil Geochemical Atlas of Ireland (SGAI). The second one is a higher resolution Tellus project database created by the Geological Survey Ireland. This study focussed on 16 metal(loid)s: As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Sb, Sn, U, V, and Zn. A Risk Quotient (RQ) and Integrated Risk Quotient (IRQ) were used to analyse individual and combined effects of selected metal(loid)s due to the potential ingestion by humans through the food chain. The results revealed that in a few locations of Ireland, the predicted environmental concentration (PEC) of As, Cd, Pb and Zn in the soil was higher than the threshold values resulting in an RQ exceedance of 1. The RQ values of metal(loid)s corresponding to the water, and sediment samples suggest minimal exceedance of threshold values. The exceedance of the IRQ values (>2) for the soil, water, and sediment samples is 32.3 %, 14.8 %, and 1.3 %, respectively. Regions along the East coast of Ireland may pose a higher potential relative risk compared to other parts of Ireland. This research suggests the need for in-depth risk assessment studies on Cd, As and Pb, which showed elevated levels. Furthermore, it is essential to understand the fate of metal(loid)s and their risk assessment to inform regulations around metal(loid)s where intervention may be required.