Application of water quality indices and health risk models in the arid coastal aquifer, Southern Saudi Arabia

• Published in: Environmental science and pollution research international 2022-10, Vol.29 (46), p.70493-70507
• Main Authors: Masoud, Milad H. Z., Rajmohan, Natarajan, Basahi, Jalal M., Niyazi, Burhan A. M.
• Format: Article
• Language: English
• Subjects: Adults; Anthropogenic factors; Aquatic Pollution; Aquifers; Aridity; Atmospheric Protection/Air Quality Control/Air Pollution; Belt conveyors; Carcinogens; Children; Coastal aquifers; Coastal waters; Contaminants; Drinking water; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental science; Evaporation; Groundwater; Groundwater quality; Groundwater treatment; Health risk assessment; Health risks; Infants; Ingestion; Nitrification; Research Article; Risk assessment; Salinity; Salinity effects; Spatial distribution; Waste Water Technology; Wastewater; Water analysis; Water Management; Water Pollution Control; Water quality; Water sampling; Wells
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-022-20835-5

A systematic study was performed in the arid coastal aquifer to evaluate groundwater quality using drinking water quality indices (DWQI) and health risk assessment models in southern Saudi Arabia. Groundwater samples were collected ( n  = 80) and analysed for major and minor ions. Results suggest that 85% of wells are unsuitable for drinking due to high salinity and hardness. Likewise, high NO 3 − and F − are encountered in 51% and 46% of wells, respectively. High salinity, Cl − and SO 4 2− are noticed in the coastal wells, which are derived from saline sources, evaporation and anthropogenic activities. High NO 3 − is originated from anthropogenic sources and the nitrification process. Recharge of wastewater with high NO 3 − is mixed with high salinity groundwater in this shallow aquifer. DWQI indicates that 66% of samples are poor to unsuitable classes. Wells with poor quality groundwater existed in the coastal belt and water quality is degraded while moving from upstream to downstream. The average values of hazard quotient (HQoral, NO 3 − , F − ) and total hazard index (THI) ensured that highly vulnerable groups are in the order of infants > children > adults. In the study region, the THI are > 1 in 75% (adults), 89% (children) and 94% (infants) of samples, respectively. The spatial distribution of HQoral reveals that groundwater in the coastal and southern regions is not advisable for direct oral ingestion, which causes serious non-carcinogenic health risk to inhabitants. Groundwater in these regions needs proper treatment to remove the contaminants before use.