Health Risk Assessment of Heavy Metals in Drinking Water: A case study in Lenabatuwa Division of Southern Sri Lanka.

Abstract

Groundwater is the major source of drinking water in the Lenabatuwa division, Kamburupitiya, Matara, Sri Lanka. This study was aimed to explore some heavy metal concentrations (Cu, Cd, Pb, Zn, Ni, and As) in drinking water and to assess the possible health risk for the people in the study area via drinking water usage. Heavy metal concentrations of the selected groundwater sources used by the locality for the drinking purpose were chemically analyzed using ICP-OES (Thermo scientific, ICAP Spectrometer 7000, UK). The values obtained were compared with the indices given by the world health organization (WHO) and Sri Lanka Standards (SLS) Institute. Average chronic daily intake (ADI), health risk quotient (HQ), and carcinogenic risk (CR) were calculated using the heavy metal concentrations. The majority of heavy metals investigated in this study area showed below the WHO and SLS standard limits. However, only a few samples were beyond the standard values of Pb and As. Moreover, drinking water quality is not according to the limits of pH. Based on the daily ingestion of water, it was revealed that the HQ is less than 1 in all samples showing no health hazard. However, according to the CR, the Pb concentrations in well water posed the lowest risk of 10−6 , and the As concentration was less to the highest risk having 10-4 in water samples in this area. Therefore, it is recommended to conduct routine monitoring in potable water sources, and appropriate measures should be taken to provide the provision of safe water to the residents in this area.