Assessment of physical parameters and potentially toxic elements in municipal water distribution systems

Abstract

Presence of the potentially toxic elements (PTEs) is a matter of serious concern when it comes to human health. Most of the previous studies conducted simply quantify the levels of these PTEs in drinking water. Contrary to those studies, the current study is aimed to quantify and correlate the PTEs at source and household levels which counts a novel study in District Swabi. About forty (n = 40) of drinking water samples were collected from six MWDS in Swabi, Pakistan. The physico-chemical parameters, including pH, electrical conductivity (EC), and total dissolved solids (TDS), were measured through Consort electrochemical analyzer Model, C931. PTEs such as Copper (Cu), Lead (Pb), Cadmium (Cd), Zinc (Zn) and Nickel (Ni) were quantified using Perkin Elmer electro-thermal Atomic Absorption Spectrometer (AAS), equipped with graphite furnace. Water Quality Index (WQI) and Hazard Index (HI) were employed to classify the severity of risk. Among the PTEs, Cd and Cr were found in concentrations above the permissible limits of WHO and USEPA. Similarly few of the samples also showed high levels of Pb and Ni. Drinking water of Maini, and Zaida distribution system were classified to be unsafe for consumption based on their WQI values of 1000 and 1814, respectively. Similarly, significant health risk (HI>1) obtained for Children and adults of Shahmansoor and Zaida due to presence of elevated PTEs levels. From findings, it can be assumed that the municipal water distribution systems Swabi district is highly contaminated with PTEs and is a source of serious health risk.