The occurrence of trihalomethanes (THMs) was studied in the drinking water samples from urban
water supply network of Karachi city that served more than 18 million people. Drinking water
samples were collected from 58 locations in summer (May-August) and winter (November-February)
seasons. The major constituent of THMs detected was chloroform in winter (92.34%) and summer
(93.07%), while the other THMs determined at lower concentrations. Summer and winter
concentrations of total THMs at places exceed the levels regulated by UEPA (80 μg l-1) and WHO
(100 μg l-1). GIS linked temporal variability in two seasons showed significantly higher median
concentration (2.5%-23.06%) of THMs compared to winter.
Assessment of physicochemical and radon-attributable radiological parameters of drinking water samples of Pithoragarh district, Uttarakhand
