Desalinated and blended water in Saudi Arabia: human exposure and risk analysis from disinfection byproducts

King Fahd University of Petroleum and Minerals, Dhahran, Dhahran 31261, Saudi Arabia

^* Corresponding author: schowdhury@kfupm.edu.sa

Abstract

Saudi Arabia produces the largest amount of desalinated water as a single country. The desalinated water is typically blended with treated groundwater, pH adjusted and chlorinated prior to supply to the communities. The desalinated seawater and/or blended water contains various types of disinfection byproducts (DBPs), some of which may induce cancer risks to human through lifetime exposure. In this study, occurrences of trihalomethanes (THMs) in desalinated and blended water in Saudi Arabia were investigated and their exposure and risks were predicted. The chronic daily intakes of CHCl₃, BDCM, DBCM and CHBr₃ were estimated to be 8.38×10⁻⁵, 7.57×10⁻⁵, 2.54×10⁻⁵ and 4.32×10⁻⁴ mg/kg-day respectively. The overall cancer risk was 1.78×10⁻⁵ with the range of 7.40×10⁻⁷ – 9.26×10⁻⁵ and the average hazard index was 3.49×10⁻² with the range of 1.20×10⁻³ – 2.34×10⁻¹. The loss of disability adjusted life years (DALY) were estimated to be 25.1 per year and the average cancer risk had 8.48×10⁻⁷ DALY per person per year. The financial burden was estimated to be US$2.72 million with the range of US$2.52–2.91 million. The findings may assist in better understanding and reducing cancer risks from DBPs in desalinated and blended water.