Drinking and irrigation quality of groundwater and health risk assessment due to arsenic exposure in Sheikhupura district, Punjab, Pakistan

Abstract

Arsenic (As) is a heavy metal that occurs naturally and contaminates groundwater. People use groundwater for many purposes, especially for drinking and agricultural uses. Groundwater contaminated with arsenic is now becoming an emerging threat in many countries, especially in Pakistan, causing severe health problems. In this study, groundwater quality is assessed for drinking and agriculture uses and health risk assessment due to arsenic exposure is calculated in the district of Sheikhupura. A total of 195 groundwater samples from fifty-eight water schemes were collected from four tehsils of the Sheikhupura district. The results show that most of the groundwater samples in case of different ions lie within the proposed range of The World Health Organization (WHO) guidelines except for arsenic concentration, which is 10 ​μg/L for drinking purposes. The concentration of arsenic ranges from 0.46 – 92.3 ​μg/L with an average value of 39.4 ​μg/L, and about 87% of the groundwater samples exceed the given limit of WHO. The Gibbs plot indicates that the significant controlling factor that changes the groundwater chemistry is rock dominance and some of the samples also lie in evaporation crystallization dominance. The arsenic (As) concentration map shows that 78% of samples the tehsil Sheikhupura, 83% of tehsil Ferozewala, 98% of tehsil Muridke, and 100% samples of tehsil Sharq-pur exceed the WHO limit. The health risk assessment is done by average daily dose (ADD), hazard quotient (HQ) and carcinogenic risk (CR) analysis. About 87% of the samples exceed the hazard quotient limit “HQ ​> ​1” with an average value of 3.654 and ranges from 0.043 – 8.546. Results indicate that people are at higher risk due to arsenic contamination in the study area; therefore, proper monitoring and management of groundwater in the Sheikhupura district is necessary.