Groundwater Quality and Health Risk Assessment in South Mut Area, New Valley, Egypt

Abstract

In the last years, some diseases have spread in Mut area in El Dakhla Oasis, which is located in the New Valley Governorate, Egypt. This study aims to investigate the correlation between the chemical characteristics of groundwater and the prevalence of certain diseases in the concerned area. So, this paper intends to assess the groundwater quality and its risks to human health for the local population
in the investigated area. This was achieved through the integration of the hydrochemical characteristics approach with an assessment of the potential health risks associated with consuming groundwater containing trace elements, heavy metals, and some minor constituents. Fifteen water samples, including Mut Lake (one sample), and fourteen groundwater samples representing the Taref, 
Sabaya and Six Hills aquifers were collected from the study area. Chemical analyses of the major ions, including Ca2+, Mg2+, Na+, K+, CO3 2-, HCO3 -, SO4 2- and Cl-, as well as some trace elements and heavy metals such as Al, Ba, Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, Sr, and minor constituents as B, were performed. Additionally, the biochemical and bacteriological analyses, such as total organic carbon
(TOC), and total colony and coliform colony counts, were assessed to evaluate the degree of contamination. The human health risks caused by intake of the contaminated groundwater through the oral and dermal pathways were also assessed. To categorize the water quality, chronic daily intakes (CDI) and health risk (hazard quotient, HQ), as well as the noncancer hazard index value (HI), were
computed for the collected water samples to assess the potential health risks associated with the groundwater in the study area. The obtained results indicated that all collected groundwater samples were classified as freshwater with salinity levels below 1105mg/l. Hypothetical salts combinations and Piper diagram revealed that there is seepage from Mut Lake to the Taref groundwater in the study area, and there is also a hydraulic connection between the Taref, Sabaya and Six Hills aquifers. By comparing the obtained results with the standard limits values in the valid drinking water guidelines, it was noticed that the majority of the groundwater (79%) in the study area was unsuitable for consumption due to excessive levels of these metals (Fe, Mn and Pb) than the permissible limits for drinking water. Additionally, the total organic carbon and microbiological examinations showed that the groundwater of the three aquifers was contaminated. It was shown that the HQ and HI values for trace elements and heavy metals and minor constituents (B) exceeded the value of 1, i.e., exposure to potentially toxic chemicals, such as iron, manganese and lead in groundwater can pose great risks to human health, i.e., the groundwater in the study area poses adverse risks on human health to the local population, which means that there is a strong relationship between the contaminants found in groundwater and some certain diseases, which is common in the study area.