Arsenic contamination of irrigation wells and associated human health hazards in the Punjab plains of Pakistan

Abstract

In the present study, the tubewell water quality, emphasizing on As contamination, were investigated in the Punjab plains of Pakistan. The Na-Cl water type is dominated in Doabs (Rechna and Chaj) whereas Ca-HCO3 water type is dominated in Ravi flood plain. Concentrations of As in well water (65 ± 32 μg/L) are higher in the floodplains of the Ravi River compared to the Chenab (13 ± 9 μg/L) and Jhelum (4 ± 5 μg/L) rivers, as well as in the intervening Rechna (6 ± 6 μg/L) and Chaj doabs (0.8 ± 0.2 μg/L). The average Hazard quotients (HQ) is 9.09E+00 and Potential Cancer Risk (CR) is 4.09E−03 in Ravi flood plain which indicates the potential health risk to the consumers of well water for drinking purposes and also long term irrigation with this water will result As accumulation in paddy soil. Based on average values, the Sodium Adsorption Ratio (SAR), Magnesium Hazard (MH), %Sodium (%Na) and Kelly Ratio (KR) follows the sequence Rechna Doab>Chaj Doab>Chenab floodplain>Jhelum floodplain>Ravi floodplain in 5 geographic units, suggesting low salinity water in floodplains and saline water in Doabs.