Trace Element (As, Cd, Cr, Cu, Pb, Se, U) Concentrations and Health Hazards from Drinking Water and Market Rice across Lahore City, Pakistan

Abstract

Exposure to toxic concentrations of trace elements in rice and drinking water is a serious issue for millions of South Asians, due to rice serving as a large portion of their diets and the geochemical enrichment of trace elements in groundwaters. The overall goal of this study was to evaluate and compare the hazards posed from toxic trace elements through the consumption of commercially available basmati rice and public drinking water sources across Lahore, Pakistan. Drinking water samples (n = 36) were collected from publicly accessible drinking taps from eight administrative towns and the cantonment. Rice samples were obtained from 11 markets (n = 33) across Lahore between December and February 2022–2023. Market rice concentrations exceeded the World Health Organization’s (WHO) limits and the Total Hazard Quotient (THQ) values exceeded 1.0 for As, Cu, and Pb, thus indicating multielement contamination. Market rice trace element concentrations and price were not correlated. As, Se, and U concentrations in drinking water were above the WHO’s drinking water guidelines and had THQ values exceeding 1.0, showing multielement contamination. Cr, Se, and U concentrations in drinking water were greater for impoverished administrative towns compared to middle and wealthy administrative towns, highlighting socioeconomic inequities in exposure to hazardous concentrations. We conclude that the citizens of Lahore are exposed to rice and drinking water that are hazardous to human health, including As and other lesser studied trace elements.