A GIS study to rank Irish agricultural lands with background and anthropogenic concentrations of metal(loid)s in soil.

Heavy metal pollution may cause a serious threat to human health and is a global problem. The bio-availability of metals and metalloids (metal (loid)s) in the soil is a dominating parameter for metal (loid) uptake by plants, and which may subsequently be ingested by individuals through the food pathway. This study aimed to develop a novel approach based on a semi-quantitative probability-impact (P-I) matrix with the help of a GIS mapping tool. ArcGIS was used for data analysis, classification, and reclassification of parameters of the model. Nine influencing parameters were selected for a semi-quantitative risk ranking. These are soil pH, soil organic carbon (SOC), soil texture class, slope, field/soil drainage class, Integrated Risk Quotient (IRQ), proximity to mines, urban activity, and potential biosolids application areas. The results revealed that certain areas (including Co. Louth, Co. Wicklow, Co. Wexford) along the East coast of Ireland pose a higher relative risk. Therefore, in-depth quantitative human health risk assessment is proposed considering the potential bioaccumulation of metal (loid)s if the crops are grown on land with elevated levels of metal (loid)s. Furthermore, this work reveals the usefulness of the GIS mapping techniques in risk assessment to rank areas of elevated levels of potential pollutants.