title: Health risk assessment of heavy metals and bacterial contamination in drinking water sources: a case study of Malakand Agency, Pakistan.
abstract: Human beings are frequently exposed to pathogens and heavy metals through ingestion of contaminated drinking water throughout the world particularly in developing countries. The present study aimed to assess the quality of water used for drinking purposes in Malakand Agency, Pakistan. Water samples were collected from different sources (dug wells, bore wells, tube wells, springs, and hand pumps) and analyzed for different physico-chemical parameters and bacterial pathogens (fecal coliform bacteria) using standard methods, while heavy metals were analyzed using atomic absorption spectrophotometry (AAS-PEA-700). In the study area, 70 % of water sources were contaminated with F. coliform representing high bacterial contamination. The heavy metals, such as Cd (29 and 8 %), Ni (16 and 78 %), and Cr (7 %), exceeded their respective safe limits of WHO (2006) and Pak-EPA (2008), respectively, in water sources, while Pb (9 %) only exceeded from WHO safe limit. The risk assessment tools such as daily intake of metals (DIMs) and health risk indexes (HRIs) were used for health risk estimation and were observed in the order of Ni > Cr > Mn > Pb > Cd and Cd > Ni > Pb > Mn > Cr, respectively. The HRI values of heavy metals for both children and adults were <1, showing lack of potential health risk to the local inhabitants of the study area.
authors.affiliation: Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China. javednawab11@yahoo.com.|Department of Environmental and Conservation Sciences, University of Swat, Swat, 19130, Pakistan. javednawab11@yahoo.com.|Department of Environmental Sciences, University of Peshawar, Peshawar, 25120, Pakistan. javednawab11@yahoo.com.
authors.forename: Javed
authors.initials: J
authors.lastname: Nawab
authors.affiliation: Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China.|Department of Environmental Sciences, University of Peshawar, Peshawar, 25120, Pakistan.
authors.forename: Sardar
authors.initials: S
authors.lastname: Khan
authors.affiliation: Department of Environmental and Conservation Sciences, University of Swat, Swat, 19130, Pakistan.
authors.forename: Sharafat
authors.initials: S
authors.lastname: Ali
authors.affiliation: Center for Plant Science and Biodiversity University of Swat, Swat, 19130, Pakistan.
authors.forename: Hassan
authors.initials: H
authors.lastname: Sher
authors.affiliation: Department of Microbiology, Abdul Wali Khan University, Mardan, Pakistan.
authors.forename: Ziaur
authors.initials: Z
authors.lastname: Rahman
authors.affiliation: Department of Environmental and Conservation Sciences, University of Swat, Swat, 19130, Pakistan.
authors.forename: Kifayatullah
authors.initials: K
authors.lastname: Khan
authors.affiliation: Institute of Urban Environment, Chinese Academy of Sciences, Xiamen, 361021, China. jftang@iue.ac.cn.
authors.forename: Jianfeng
authors.initials: J
authors.lastname: Tang
authors.affiliation: Department of Environmental and Conservation Sciences, University of Swat, Swat, 19130, Pakistan.
authors.forename: Aziz
authors.initials: A
authors.lastname: Ahmad
mesh_terms: D000328:Adult; D002648:Child; D060766:Drinking Water / Q000032:analysis / Q000737:chemistry*; D004781:Environmental Exposure / Q000032:analysis* / Q000706:statistics & numerical data; D004784:Environmental Monitoring; D006801:Humans; D019216:Metals, Heavy / Q000032:analysis*; D010154:Pakistan; D018570:Risk Assessment; D013054:Spectrophotometry, Atomic
chemical_list: D060766:Drinking Water; D019216:Metals, Heavy
keywords: Correlation; Daily intake; Drinking water; Health risk; Heavy metals; Local inhabitants; Pathogens