Ground water toxicity due to fluoride contamination in Southwestern Lahore, Punjab, Pakistan

Abstract

Abstract The prevalence of dental/bone deformities provides motivation for studying the distribution, severity and sources of the Fluoride (F−1). The ground water samples (n = 77) were collected, from the districts of Lahore and Kasur of approximately 750 km2 area. The water was analyzed for fluoride (F−), pH, electric conductivity (EC), alkalinity and hardness. The results revealed F− concentration ranges from 0.25–21.3 mg. An inverse relation between depth and fluoride concentration was observed. On the basis of cluster analysis three zones were identified. Highly toxic zone was a strip of 15 km wide and 3 km long, along Multan Road from Sunder to Phool Nagar bypass, with fluoride concentration (08–21.3 mg/L). The highly toxic zone inhabited a number of industrial units, disposing off their wastewater through soaking pits. These units contribute pollution to the shallow water, which further penetrates to the surroundings. Hence the shallow water (depth of 45–50 feet) was the most contaminated. The intensity of toxic effects decreases from highly to mild toxic zone. It was concluded that the problem was actually associated with the industrial wastewater. Therefore, to overcome the issue, measures of supplying fresh drinking water from the deep aquifer as well as treatment of industrial water is suggested. HIGHLIGHT Industry was actually responsible for fluoride toxicity in the region rather than natural sources.