Human and Ecological Risk Assessment: An International Journal ISSN: 1080-7039 (Print) 1549-7860 (Online) Journal homepage: http://www.tandfonline.com/loi/bher20 Arsenic and Heavy Metal Concentrations in Drinking Water in Pakistan and Risk Assessment: A Case Study Sardar Khan, Irfan Ali Shah, Said Muhammad, Riffat Naseem Malik & Mohammad Tahir Shah To cite this article: Sardar Khan, Irfan Ali Shah, Said Muhammad, Riffat Naseem Malik & Mohammad Tahir Shah (2015) Arsenic and Heavy Metal Concentrations in Drinking Water in Pakistan and Risk Assessment: A Case Study, Human and Ecological Risk Assessment: An International Journal, 21:4, 1020-1031, DOI: 10.1080/10807039.2014.950925 To link to this article: https://doi.org/10.1080/10807039.2014.950925 View supplementary material Accepted author version posted online: 08 Aug 2014. Published online: 06 Dec 2014. Submit your article to this journal Article views: 619 View related articles View Crossmark data Citing articles: 14 View citing articles Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=bher20 Human and Ecological Risk Assessment, 21: 1020–1031, 2015 Copyright C Taylor & Francis Group, LLC ISSN: 1080-7039 print / 1549-7860 online DOI: 10.1080/10807039.2014.950925 Arsenic and Heavy Metal Concentrations in Drinking Water in Pakistan and Risk Assessment: A Case Study Sardar Khan,1 Irfan Ali Shah,1 Said Muhammad,2 Riffat Naseem Malik,3 and Mohammad Tahir Shah4 1Department of Environmental Sciences, University of Peshawar, Peshawar, Pakistan; 2Department of Earth Sciences, COMSATS Institute of Information Technology, Abbottabad, Pakistan; 3Environmental Biology and Ecotoxicology Laboratory, Department of Environmental Sciences, Faculty of Biological Sciences, Quaid-I-Azam University, Islamabad, Pakistan; 4National Center of Excellence in Geology, University of Peshawar, Peshawar, Pakistan ABSTRACT The present study was performed to assess drinking water quality and poten- tial health risk in the Nowshera District, Khyber Pakhtunkhwa, Pakistan. For this purpose drinking water samples were collected from local available sources and an- alyzed for physico-chemical characteristics, arsenic (As) and heavy metals. Results revealed high levels of toxic heavy metals such as chromium (Cr), nickel (Ni), lead (Pb), cadmium (Cd), and As contaminations in the drinking water. Results were evaluated for chronic risk including average daily intake (ADI) and hazard quotient (HQ). Among heavy metals the HQ values were highest for Cd (5.80) and As (2.00). Therefore, populations in the study area may be at a low level of chronic toxicity and carcinogenic risk. Statistical analyses showed that contribution of different drinking water sources to the mean contaminant levels in the study area was insignificant (p = .53). Correlation analysis further revealed that anthropogenic activities were the main sources of contamination, rather than geogenic. This study strongly recom- mends the treatment of urban and industrial wastewater in the vicinity of the study area and provision of safe drinking water. Key Words: drinking water, hazard quotient, average daily intake, cancer risk, statistical analyses, Nowshera District. Received 8 March 2014; revised manuscript accepted 28 July 2014. Address correspondence to Sardar Khan, Department of Environmental Sciences, Univer- sity of Peshawar, Peshawar 25120, Pakistan. E-mail: [email protected]; or to Said Muhammad, Department of Earth Sciences, COMSATS Institute of Information Technology, Abbottabad 22060, Pakistan. E-mail: [email protected] Color versions of one or more of the figures in the article can be found online at www. tandfonline.com/bher. 1020 Arsenic and Heavy Health Risk Assessment via Drinking Water INTRODUCTION Drinking water contaminations have both natural (ore deposits, rocks weather- ing, and erosion) and anthropogenic (industries, mining, agriculture activities, and wastewater) origins (Muhammad et al. 2010; Khan et al. 2013; Li et al. 2014). Among contaminants the heavy metals are of global concern, which find their ways into water and food, impairing their quality and cause toxicity (Shah et al. 2012; Spayd et al. 2012; Hu et al. 2014). Among metals, sodium (Na), calcium (Ca), magnesium (Mg), zinc (Zn), cobalt (Co), iron (Fe) and copper (Cu) are essential and required at certain concentrations for normal body function and growth. However, others such as As, Cd, Ni, and Pb are non-essentials or toxic metals and causing numerous human health risks after ingestion (Muhammad et al. 2010, 2011). Toxic effects of these metals include abdominal pain, headache, irritability, blood pressure, kidney damage, nerve damages, skeletal damage, cancer, and affects intellectual functions (Khan et al. 2013). Characteristically, heavy metals are mostly carcinogenic in na- ture but their toxicity and targeted organs vary from metal to metal and also depend on the ingested amount, body immunity of the individual, and exposure duration (Goyer et al. 2004). Heavy metals enter into the human body through several path- ways. However, oral ingestion, especially through drinking water, is one of the major sources for human exposure (Spayd et al. 2012; Khan et al. 2013). Humans need drinking water for sustaining life and social prosperity. Provision of clean water supplies is a high priority issue for safe guarding a population’s health (Simeonov et al. 2002). Clean drinking water and its adequate supply is a key factor contributing to decreased mortality and morbidity and improved economic development in the developing countries (Koc 2010). Therefore, human health risk assessment through drinking water consumption has become the prime focus of environmental researchers globally (Spayd et al. 2012). Being a developing country, Pakistan is facing a serious crisis in the supply of clean and safe portable water in its urban and rural areas. In the past, few studies have been reported on the drinking water contaminations in the northern region of Pakistan (Muhammad et al. 2010, 2011; Shah et al. 2012; Khan et al. 2013). Although, the Nowshera District hosts a population of more than 1.2 million, no research has been carried out on drinking water quality and it potential health risk. Therefore, this study aimed to identify the sources of drinking water contaminations and their potential health risk assessment in the selected district. METHODS AND MATERIALS Study Area The Nowshera District is located along the banks of the Kabul River and lies between 33◦–41 to 34◦–10 N latitudes and 71◦–39 to 72◦–16 E longitudes, with a total area of 1748 km2 (Figure 1). It is bounded on the east by the Attock Dis- trict of Punjab Province, on the west by Peshawar and on the northwest side by Charsadda, while on the northern side by the Mardan and Swabi Districts and on the south by the Kohat District. The district is cold (4◦C) in winter and very warm (43◦C) in the summer, receiving an annual precipitation of 600 mm. Generally, depth in water tables varies from 13–50 meters. The main professions of the local Hum. Ecol. Risk Assess. Vol. 21, No. 4, 2015 1021 S. Khan et al. Figure 1. Map of the study area showing locations of the sampling sites. residents are agriculture, business and jobs in government institute, or the Aman- garh Industrial Estate (AIE). The AIE hosts a number of paper, textile, ceramics, tanneries, and ghee industries. The Kabul River enters this district at its western side and runs through the plain and joins the Indus River at a kund near Khairabad (DCR 1998). 1022 Hum. Ecol. Risk Assess. Vol. 21, No. 4, 2015 Arsenic and Heavy Health Risk Assessment via Drinking Water Water Samplings and Analyses Inhabitants of the Nowshera District are using tube wells, bore wells, dug wells, and hand pumps as sources of water for drinking purposes. The district was classified into 39 sampling sites and each site into three spots (Figure 1). From each spot, water was collected in two plastic bottles. Basic parameters such as pH and electrical conductivity (EC) were measured on the spot using water quality checker U-10 Horriba-Japan. The location of each sampling site was noted using a global positional system (GPS). Water of one bottle was acidified at each sampling spot for As and heavy metal analyses, while another bottle was non-acidified and tested for anions including nitrate (NO3), sulphate (SO4), and chloride (Cl). Collected samples were transported and stored in the dark at 4◦C for further analyses (APHA 2005). Nitrate, SO4, and Cl were measured in non-acidified samples by the titration method adopted from the American Public Health Association (APHA 2005). Light metals (Na, K, Ca, and Mg) and heavy metals (Pb, Cu, Cr, Ni, Cd, and Zn) were measured using a graphite atomic absorption spectrophotometer (Perkin Elmer, AAS-PEA-700), while As concentrations were measured using a mercury hydride system (MHS). Analyses were performed in triplicate. Reproducibility was found to be at 95% confidence level. Therefore, mean values of samples were used for results interpre- tation. Reliability and reproducibility of analyses were checked by analyzing blank and known standards after every 10 samples. Chemicals (acids and reagents) used in samples’ analyses were of analytical grade and purchased from MERCK & Co., Inc. All analyses were performed in the geochemistry laboratory of the National Centre of Excellence in Geology (NCEG), University of Peshawar, Pakistan. Potential Risk Assessment Exposure assessment For exposure assessment of the study area, the average daily intake (ADI) of metals through drinking consumptions is calculated according to the equation adopted from the U.S. Environmental Protection Agency (USEPA 1998) and Shah et al. (2012). ADI = CW × IR × EF × ED/BW × AT (1) where CW is the concentration of metals in water (mg/L), EF is the exposure frequency (365 days/year), IR is the ingestion rate of water (L/day), ED is expo- sure duration (30 years), BW is bodyweight (60 kg), and AT is averaging time, i.e., 365 days/year × ED for non-carcinogens and 365 days/year × 70 years for carcino- gens (ATSDR 2008; WHO 2011; Shah et al.