An Inter-disciplinary Approach to Evaluate Human Health Risks Due to Long-Term Exposure to Contaminated Groundwater Near a Chemical Complex

Abstract

Potentially toxic elements (PTEs) are known to threat human health due to exposure to contaminated groundwater. Some of these PTEs can lead to long-term carcinogenic and non-carcinogenic health risks. The Estarreja Chemical Complex (ECC), NW Portugal, has had an intense industrial activity since the early 1950s, which lead to high levels of soil and groundwater contamination. Local populations traditionally rely on groundwater for human and agricultural uses. Although rehabilitation measures have been implemented for the last 20 years, groundwater contamination levels remain high for some PTEs, whose concentrations may be several orders of magnitude higher than human consumption. Two groundwater-sampling campaigns were conducted showing the temporal evolution of groundwater quality and allowing for the calculation of non-cancer and cancer risks due to exposure to PTEs by the ECC-surrounding population, considering groundwater ingestion and dermal contact as exposure pathways. Hair and urine PTE contents were collected during of the second sampling groundwater campaign and were used as biomonitoring to validate the exposure of local population to PTEs. The results show that As is the contaminant with highest non-cancer and cancer health risks for the exposed population, presenting high values particularly in Veiros, Beduido and Pardilho localities. The most groundwater-contaminated areas coincided with the localities in which inhabitants exhibit higher hair and urinary PTE concentrations. Hair samples show high levels of As, Hg and Ni, while urine samples show high levels for Al, As, Cd, Hg, Pb, Ni and Zn are elevated in localities close to the ECC. Urine and hair proved to be suitable to evaluate short- and long-term exposure to PTEs, and are strongly correlated groundwater PTEs concentrations.