Listen
graphic
View largeDownload slide

The Ghizer River Basin (GRB) is one of the sub-basins of the Indus River hosting rich mineralization and agrogenic activities. The GRB was sampled for 55 water samples and investigated for potentially harmful element (PHE) concentrations using inductively coupled plasma mass spectrometry. PHE concentrations in water of the GRB were used to calculate the potential of non-cancer risks such as chronic daily intake (CDI), hazard quotient (HQ), and cancer risk (CR). The highest average concentrations of chromium (37.1 ± 17.1 μg/L), copper (27.4 ± 12.5 μg/L), arsenic (4.8 ± 0.9 μg/L), cobalt (9.2 ± 3.3 μg/L), and nickel (62.7 ± 27.6 μg/L) were noted for the Ishkomen River segment of the GRB. Similarly manganese (417 ± 144 μg/L), cadmium (1.95 ± 0.02 μg/L), lead (7.7 ± 1.4 μg/L), and zinc (28.4 ± 5.5 μg/L) concentrations were maximum at downstream of the GRB. Geospatial and statistical analyses showed that lithogenic sources contributed higher to PHE contamination in the water of the GRB than the agrogenic sources. PHE concentrations were noted under the World Health Organization (WHO) drinking water thresholds, except for nickel. Results showed the uppermost CDI value of 13.6 μg/kg-day for manganese and HQ value of 0.52 for arsenic via water intake of children. Non-cancer and CR values through water intake were under the US Environmental Protection Agency (USEPA) thresholds and noted as suitable for drinking and other domestic purposes.

Listen

  • Potentially harmful element (PHE) levels were measured in the water of the Ghizer River.

  • Hazard quotient values via consumption of PHE in drinking water were noted as <1.

  • Cancer risk values via consumption of arsenic were noted within the USEPA threshold.

  • Children were observed at higher risk than adults via consumption of drinking water.

  • Geogenic sources contributed mainly to PHE contamination in drinking water.

cancer risk, chronic daily intake, Gilgit-Baltistan, hazard quotient, Ishkomen river, Yasin river
Listen
GRB

Ghizer River Basin

PHEs

potentially harmful elements

CDI

chronic daily intake

HQ

hazard quotient

CR

cancer risk

Cr

chromium

Cu

copper

As

arsenic

Co

cobalt

Ni

nickel

Mn

manganese

Cd

cadmium

Pb

lead

Zn

zinc

WHO

World Health Organization

USEPA

US Environmental Protection Agency

MKT

Main Karakorum Thrust

KIA

Kohistan Island Arc

CVG

Chalt Volcanic Group

ICP-MS

inductively coupled plasma mass spectrometry

HNO3

nitric acid

C

concentration

IR

average daily ingestion rate

BW

body weight

Rfd

reference dose

PCA

principal component analysis

CSF

cancer slope factor

Listen

Potentially harmful elements (PHE) are ubiquitous and extremely hazardous contaminants in the environment owing to their high persistency, toxicity, and bioaccumulative nature (Lee et al. 2022; Saravanan et al. 2022). However, few PHE such as zinc (Zn), copper (Cu), and iron (Fe) are essentially required in a specific range for the growth of living beings (Chelyadina et al. 2023; Ismanto et al. 2023). However, an excessive amount of these PHE is considered toxic for the organism (Din et al. 2023; Hassan et al. 2023). PHE including lead (Pb), cadmium (Cd), and arsenic (As) are toxic and hazardous in a very small amount (Ayejoto et al. 2023; Chibuike et al. 2023). These PHE discharged into the aquatic system not only impact the riverine ecosystem (Schwantes et al. 2021) but also contaminate the food chain, and pose risks to human health (Muhammad et al. 2022a; Zhao et al. 2023). PHE is discharged into the riverine system from both lithogenic processes (natural denudation of minerals deposits and bedrocks) (Muhammad 2023) and anthropic (industrial, domestic, and municipal wastewater, and agrogenic and mining) activities (Iordache et al. 2022; Kumar et al. 2022; Xie et al. 2022).

Rivers, streams, lakes, and reservoirs are one of the major sources of water supply for drinking and domestic purposes in remote rural and urban areas of developing countries (Hinrichsen & Tacio 2002; Zhang et al. 2010; Muhammad & Ahmad 2020; Abd-Elaty et al. 2022; Nivesh et al. 2023). Therefore, water characteristics of these water sources have been regularly tested for contamination levels (Selvam et al. 2022) and risk indices (Xie & Ren 2022), which provide a useful tool for understanding the stakeholders including the public and policy-maker in decisions about its management and conversation (Pace et al. 2022; Williams et al. 2023). Geospatial analysis help in finding the sources of water contamination in river and conservation (Khafaji et al. 2022; Singh & Noori 2022; Ismail et al. 2023).

Rivers are one of the most important links in hydrologic circulation on the earth. The river plays a key role in the circulation and transportation of PHE and energy along the hydrological gradients (Heerspink et al. 2020; Ali & Muhammad 2023). Rivers of aquatic ecosystem flow through hundreds and thousands of kilometers and are hence more exposed and vulnerable to contamination from both geogenic and anthropic factors (Islam et al. 2022; Muhammad & Usman 2022). Over the last few decades, the lithogenic and anthropic factors such as agriculture, mining, and industrial activities have been accelerated that resulted in water contamination of the riverine basin, particularly in low-income countries (Xiao et al. 2021; Hao et al. 2022; Muhammad et al. 2022b).

Recently, PHE contamination in river water and potential risk assessment has been reported from various countries such as Bangladesh (Haque et al. 2022), China (Yu et al. 2022), India (Bhat et al. 2023), and Iran (Fallah et al. 2022). However, such studies on PHE contamination and risk assessment have been rarely reported especially in northern Pakistan (Ali & Muhammad 2022). Rich mineralization has been observed along Main Karakoram Thrust (MKT) and Kohistan Island Arc (KIA) (Kazmi & Jan 1997). In addition, the Ghizer River Basin (GRB) is also famous for its supply of various agricultural products in the region. The GRB flows along this rich mineralized zone and supplies water for agrogenic activities. Lithogenic processes such as the denudation of minerals and bedrock, and agrogenic activities could be sources of water contamination in the GRB. So far, water contamination of PHE along the GRB has not been examined. This is the first comprehensive study on the GRB related to PHE contamination in water and will provide baseline information for future works. The objectives of the present study were to (1) determine the spatial variation of PHE in the water of the GRB, (2) assess the non-cancer and cancer risks through water consumption of the GRB, (3) spatial distribution map of the cancer risk through water consumption of the GRB, and (4) identify the sources of PHE contamination in water using statistical and geospatial techniques.

Listen

Study area

Listen
The GRB is located in the northern part of Pakistan and it comprises four tehsils including Gupis, Ishkomen, Punial, and, Yasin, with a Gilgit area as well, which lies at latitudes 35°42′39″N–36°55′51″N and longitudes 74°22′12″E–72°30′22″E between Gilgit and Chitral districts (Figure 1). This valley connects the Chitral district with the Gilgit district through Shandur Pass. Several rivers divided the area into small sub-valleys and major valleys including Ishkomen, Yasin, Hunza, and Ghizer.
Figure 1
Study area and sampling locations of the Ghizer River Basin, northern Pakistan.
View largeDownload slide

Study area and sampling locations of the Ghizer River Basin, northern Pakistan.

Figure 1
Study area and sampling locations of the Ghizer River Basin, northern Pakistan.
View largeDownload slide

Study area and sampling locations of the Ghizer River Basin, northern Pakistan.

Close modal

The study area generally consisted of the fluvial plain deposits and tectonic units such as KIA and the Asian plate. Here, in the KIA unit, granite, trondhjemite, hornblendite, diorite, quartz, gabbro, leucogranite, and granodiorite were found (Jagoutz & Schmidt 2013). The MKT also knows the Shyok Suture or Kohistan Suture zone and passed through the study area. The MKT act as a boundary line between the Asian Plate and KIA. Ghizer formation consists of these geological formations, including basalt, pyroclastic, and andesite-dominated crystalline rocks that can be seen in the Ishkomen Valley. Chalt Volcanic Group (CVG) formation was visible in the surrounding Sharman Village (Pudsey 1986; Kazmi & Jan 1997).

Water sampling and preparation

Listen

In this research study, during August 2020, 55 water samples were collected in 250-mL plastic bottles from various locations in the GRB. This covered almost the entire area of the GRB including Yasin River (n = 05), Ishkomen River (n = 09), Midstream of Ghizer River (n = 18), Downstream of Ghizer River (Gilgit region) (n = 08), and Upstream of Ghizer River (n = 15) Figure 1. The geographical coordinates of each sampling point were recorded with the help of a hand-held global position system (GPS). Prior to sampling, the bottle was washed several times with sampling water. For the preservation of PHE and to prevent microbial activity, the collected samples were acidified with nitric acid (HNO3, 65%, Merck). The collected water samples were filtered through a Whatman filter paper of pore size 42 μm, labeled, shifted to the laboratory, and stored at 4 °C. An inductively coupled plasma mass spectrometer (ICP-MS, PerkinElmer Optima 7000 DV, USA) was used for the measurement of selected PHE concentrations in collected water samples.

Precision and accuracy

Listen

Standard procedures were adopted during sampling and laboratory analysis according to the American Public Health Association (APHA) guidelines to obtain accurate and correct outcomes. For PHE analysis, a blank and three standard sample solutions (2.5, 5, and 10 mg/l) of each selected PHE were analyzed using ICP-MS. During analysis, the blanks and standard solutions were repeated after 10 samples to check for accuracy. The reproducibility was achieved with a 95% confidence level. The mean score of each sample was used for the interpretation of the results.

Risk assessment

Listen

Chronic daily intake

Listen
The PHE enter the human body through various pathways, such as oral, respiratory, and dermal contact. Oral contact with PHE is more significant than other exposures (Ullah et al. 2019). The surface water of the study area is used for drinking and other domestic purposes. Therefore, CDI was calculated through the consumption of water in the GRB according to Equation (1) (Muhammad et al. 2011; USEPA 1999):
(1)
where C, IR, and BW show the PHE concentration(μg/L) in surface water, the average daily ingestion rate, and the body weight, respectively. For adults and children, the BW value is 70 and 30.6 kg, respectively (Muhammad & Ahmad 2020). Average water consumption by adults was noted to be 2 L/day, whereas in children it was 1 L/day (USEPA 2011).

Hazard quotient

Listen
The HQ was used to determine non-cancer risks according to Equation (2) (USEPA 1999) and other authors (Kavcar et al. 2009; Jadoon et al. 2019).
(2)

For PHE, the reference dose values (RfD in μg/kg-day is Cd (0.5), Ni (20), Pb (36), Co (30) Zn (300), Cu (37), Mn (140), Cr (1,500), Sb (0.3), and As (0.3) were modified by the USEPA (2005).

Cancer risk

Listen
The CF was determined by the following equation (USEPA 2010; Alarcón-Herrera et al. 2020):
(3)
where the CSF shows the ‘cancer slope factor’ for As and its value is ‘1.5 mg/kg/day’ (USEPA 2005).

Statistical analyses

Listen

Statistical analyses were performed, including Pearson's correlation (PC) and principal component analysis (PCA) using SPSS 20 and Sigma Plot Ver. 12.5 for graphical representation. GPS was used to record each collected sample point coordinates. These coordinates were further used to plot the spatial distribution of the selected PHE concentrations using ArcMap (Version 10.3).

Listen

PHE concentrations

Listen
The average and standard deviation values of PHE for the GRB were summarized (Table 1). The concentrations of PHE were plotted for each sample in the geospatial distribution and results were summarized (Figure 2). The geospatial distribution maps were noted for a great variation observed among the PHE in water and within the segments of the GRB. Among the studied PHE, the uppermost average concentration of 417 ± 144 μg/L was noted for Mn and the lowermost 0.01 μg/L for Co and Sb in the GRB. Among segments of the GRB, Ishkomen River was noted with the maximum average concentration of Cr (37.1 ± 17.1 μg/L), Cu (27.4 ± 12.5 μg/L), As (4.8 ± 0.9 μg/L), Co (9.2 ± 3.3 μg/L), and Ni (62.7 ± 27.6 μg/L) compared to others (Table 1). PHE concentrations in the water of the Ishkomen River was due to the enrichment bedrock and mineralization in the vicinity (Miller et al. 1991; Arif 2000; Saddique et al. 2018). However, uppermost average concentrations for Mn (417 ± 144 μg/L), Cd (1.95 ± 0.02 μg/L), Pb (7.7 ± 1.4 μg/L), and Zn (28.4 ± 5.5 μg/L) were noted in the collected Downstream of Ghizer River. Average values of these PHE in GRB were noted under the threshold values suggested by the World Health Organization (WHO 2011). However, the concentration of Ni collected from Ishkomen River and Downstream of Ghizar River had surpassed these threshold limits. In this study, PHE concentrations were noted to be higher than in a previous study in the surroundings as examined by Muhammad & Ahmad (2020) for the Hunza River (Table 2). This increase in PHE concentration in the water samples of the GRB was due to variations in bedrock geology and other prevailing agrogenic activities.
Table 1

Statistical description of PHE concentration (μg/L) in the water samples of the Ghizer River Basin

PHEIshkomen River
Yasin River
Upstream Ghizer River
Midstream Ghizer River
Downstream Ghizer River
WHO
n = 9
n = 5
n = 15
n = 18
n = 8
RangeMean ± SDRangeMean ± SDRangeMean ± SDRangeMean ± SDRangeMean ± SD
As 0.3–8.0 4.8 ± 0.9 0.5–1.7 1.4 ± 0.2 0.1–4.6 1.9 ± 0.4 0.02–6.2 2.0 ± 0.4 0.3–5.6 3.1 ± 0.6 10 
Cu 1.8–112.3 27.4 ± 12.5 2.3–8.7 6.8 ± 1.1 0.1–9.3 4.8 ± 0.7 0.1–13.4 5.7 ± 1.0 0.2–74.5 22.9 ± 8.1 2,000 
Cr 3.9–127 37.1 ± 17.1 0.2–3.9 1.1 ± 0.7 2.0–4.8 3.6 ± 0.2 0.5–15.9 4.8 ± 1.0 4.6–30.8 15.4 ± 2.9 50 
Co 0.2–27 9.2 ± 3.3 0.4–2.7 1.9 ± 0.4 0.01–1.8 0.8 ± 0.1 0.02–7.4 2.2 ± 0.5 0.1–20.7 8.5 ± 2.2 40 
Ni 1.4–227 62.7 ± 27.6 1.6–9.4 7.0 ± 1.4 0.1–3.6 1.9 ± 0.4 2.1–30 9.9 ± 2.1 3.5–86.1 37.2 ± 8.7 20 
Mn 9.2–985 344 ± 118 12.7–110 84.4 ± 18 1.2–61.6 29.9 ± 5.5 0.05–273 89.2 ± 22.3 0.6–1,312 417 ± 144 500 
Pb 0.2–18.0 6.9 ± 1.9 1.4–6.1 5.0 ± 0.9 0.04–6.4 2.2 ± 0.5 0.02–7.6 3.0 ± 0.6 0.01–13.1 7.7 ± 1.4 10 
Cd 1.92–2.05 1.95 ± 0.01 1.92–1.95 1.93 ± 0.01 1.90–1.95 1.91 ± 0.0 1.90–2.00 1.93 ± 0.01 1.90–2.07 1.95 ± 0.02 3 
Zn 3.2–41.5 23.2 ± 3.9 0.5–20.2 15 ± 3.7 1.8–5.2 3.3 ± 0.2 0.3–29 11.6 ± 2.2 3.0–52 28.4 ± 5.5 3,000 
Sb 0.01–3.2 1.0 ± 0.3 1.9–4.9 4.2 ± 0.6 1.3–2.2 1.8 ± 0.1 0.4–7.2 1.8 ± 0.4 0.1–2.1 0.7 ± 0.2 20 
PHEIshkomen River
Yasin River
Upstream Ghizer River
Midstream Ghizer River
Downstream Ghizer River
WHO
n = 9
n = 5
n = 15
n = 18
n = 8
RangeMean ± SDRangeMean ± SDRangeMean ± SDRangeMean ± SDRangeMean ± SD
As 0.3–8.0 4.8 ± 0.9 0.5–1.7 1.4 ± 0.2 0.1–4.6 1.9 ± 0.4 0.02–6.2 2.0 ± 0.4 0.3–5.6 3.1 ± 0.6 10 
Cu 1.8–112.3 27.4 ± 12.5 2.3–8.7 6.8 ± 1.1 0.1–9.3 4.8 ± 0.7 0.1–13.4 5.7 ± 1.0 0.2–74.5 22.9 ± 8.1 2,000 
Cr 3.9–127 37.1 ± 17.1 0.2–3.9 1.1 ± 0.7 2.0–4.8 3.6 ± 0.2 0.5–15.9 4.8 ± 1.0 4.6–30.8 15.4 ± 2.9 50 
Co 0.2–27 9.2 ± 3.3 0.4–2.7 1.9 ± 0.4 0.01–1.8 0.8 ± 0.1 0.02–7.4 2.2 ± 0.5 0.1–20.7 8.5 ± 2.2 40 
Ni 1.4–227 62.7 ± 27.6 1.6–9.4 7.0 ± 1.4 0.1–3.6 1.9 ± 0.4 2.1–30 9.9 ± 2.1 3.5–86.1 37.2 ± 8.7 20 
Mn 9.2–985 344 ± 118 12.7–110 84.4 ± 18 1.2–61.6 29.9 ± 5.5 0.05–273 89.2 ± 22.3 0.6–1,312 417 ± 144 500 
Pb 0.2–18.0 6.9 ± 1.9 1.4–6.1 5.0 ± 0.9 0.04–6.4 2.2 ± 0.5 0.02–7.6 3.0 ± 0.6 0.01–13.1 7.7 ± 1.4 10 
Cd 1.92–2.05 1.95 ± 0.01 1.92–1.95 1.93 ± 0.01 1.90–1.95 1.91 ± 0.0 1.90–2.00 1.93 ± 0.01 1.90–2.07 1.95 ± 0.02 3 
Zn 3.2–41.5 23.2 ± 3.9 0.5–20.2 15 ± 3.7 1.8–5.2 3.3 ± 0.2 0.3–29 11.6 ± 2.2 3.0–52 28.4 ± 5.5 3,000 
Sb 0.01–3.2 1.0 ± 0.3 1.9–4.9 4.2 ± 0.6 1.3–2.2 1.8 ± 0.1 0.4–7.2 1.8 ± 0.4 0.1–2.1 0.7 ± 0.2 20 
View Large
Table 2

Comparison of the mean concentration (μg/L) of PHE of the Ghizer River Basin with other river studies

LocationCuCrCoNiMnAsSbZnCdPbReferences
Ghizer River, Pakistan 13.5 12.4 4.53 23.7 193 2.63 1.90 16.3 1.93 5.00 This study 
Indus River, Pakistan 59.7 19.9 13.7 17.5 17.6    1.3 5.1 Muhammad & Usman (2022)  
Kunhar River, Pakistan 142 13.7 11.0 6.92     3.03 4.51 Muhammad et al. (2022b)  
Hunza River, Pakistan 5.80 8.49 2.28 11.2    64.3 1.38 3.68 Muhammad & Ahmad (2020)  
Dor River, Pakistan  42.7 113 68.5 85.9   54.7 2.3 13.3 Amin et al. (2021)  
Zhob River, Pakistan 450 55 85 35 185    3.5 55 Ullah et al. (2019)  
Kabul River, Pakistan 140 270 580 960 3,470  4,900 1,140   Idrees et al. (2017)  
Swat River, Pakistan 9.62 440  59.6 136   21.0 11.6 BDL Khan et al. (2013)  
Bhairab River, Bangladesh  31.4    9.36   1.44 23.8 Ali et al. (2022)  
Fenghe River Basin, China 2.07 7.01  2.12 83.3 1.63  12.1 0.04 0.96 Luo et al. (2021)  
Sutlej River, India 6.05 21.8 24.9 19.2    285 16.6 113 Setia et al. (2020)  
Ajay River, India 72  23 17 160  242 30 53  Singh & Kumar (2017)  
Sardabrud River, Iran 2.58 2.63 0.85  38.2 1.25  8.43 0.05 4.11 Reyhani et al. (2013)  
LocationCuCrCoNiMnAsSbZnCdPbReferences
Ghizer River, Pakistan 13.5 12.4 4.53 23.7 193 2.63 1.90 16.3 1.93 5.00 This study 
Indus River, Pakistan 59.7 19.9 13.7 17.5 17.6    1.3 5.1 Muhammad & Usman (2022)  
Kunhar River, Pakistan 142 13.7 11.0 6.92     3.03 4.51 Muhammad et al. (2022b)  
Hunza River, Pakistan 5.80 8.49 2.28 11.2    64.3 1.38 3.68 Muhammad & Ahmad (2020)  
Dor River, Pakistan  42.7 113 68.5 85.9   54.7 2.3 13.3 Amin et al. (2021)  
Zhob River, Pakistan 450 55 85 35 185    3.5 55 Ullah et al. (2019)  
Kabul River, Pakistan 140 270 580 960 3,470  4,900 1,140   Idrees et al. (2017)  
Swat River, Pakistan 9.62 440  59.6 136   21.0 11.6 BDL Khan et al. (2013)  
Bhairab River, Bangladesh  31.4    9.36   1.44 23.8 Ali et al. (2022)  
Fenghe River Basin, China 2.07 7.01  2.12 83.3 1.63  12.1 0.04 0.96 Luo et al. (2021)  
Sutlej River, India 6.05 21.8 24.9 19.2    285 16.6 113 Setia et al. (2020)  
Ajay River, India 72  23 17 160  242 30 53  Singh & Kumar (2017)  
Sardabrud River, Iran 2.58 2.63 0.85  38.2 1.25  8.43 0.05 4.11 Reyhani et al. (2013)  
View Large
Figure 2
Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.
View largeDownload slide
Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.
View largeDownload slide

Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.

Figure 2
Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.
View largeDownload slide
Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.
View largeDownload slide

Spatial distribution of PHEs (μg/L) in the Ghizer River Basin, northern Pakistan.

Close modal

Risk assessment

Listen

The PHE concentration in the GRB was used for the risk assessment such as CDI and HQ (Muhammad & Ahmad 2020).

Chronic daily intake

Listen
The daily exposure rate such as CDI for the PHE contamination through drinking water was calculated and results were summarized (Figure 3(a) and 3(b)). Results revealed the uppermost CDI value of 13.6 μg/kg-day for Mn through drinking water intake of children and lowermost 0.02 μg/kg-day for Sb Downstream of Ghizer River in adults. The majority of PHE was noted with higher CDI values at Ishkoman River, GRB, except for Mn, Pb, and Zn Downstream of Ghizer River, and Sb in Yasin River (Figure 3(a) and 3(b)). Higher CDI values of PHE in these segments of GRB were due to their maximum concentration released by the lithogenic processes, domestic, and agrogenic activities. Among human age groups, children were noted with higher CDI values for PHE than adults (Figure 3(a) and 3(b)). These higher CDI values of children were attributed to their low body weight. Higher CDI values of children for PHE consumption were noted consistent with a similar nature previous study (Emmanuel et al. 2022). The CDI values of GRB were noted as lesser than that of Naltar Lakes in the vicinity (Muhammad 2023).
Figure 3
Chronic daily intake (μg/kg-day) values of (a) children and (b) adults through water consumption in the Ghizer River Basin.
View largeDownload slide

Chronic daily intake (μg/kg-day) values of (a) children and (b) adults through water consumption in the Ghizer River Basin.

Figure 3
Chronic daily intake (μg/kg-day) values of (a) children and (b) adults through water consumption in the Ghizer River Basin.
View largeDownload slide

Chronic daily intake (μg/kg-day) values of (a) children and (b) adults through water consumption in the Ghizer River Basin.

Close modal

Hazard quotient

Listen
The calculated HQ for PHE consumption via water was summarized (Figure 3(a) and 3(b)). Results revealed the maximum average value of 0.52 of HQ for As via consumption of drinking water in children and a minimum of <0.01 for Cr in adults at Yasin River and Upstream of Ghizer River. The average HQ values of PHE were noted as less than 1 and under the safe threshold limits USEPA (1999). Elements including As, Cu, Cr, Co, and Ni were noted with higher average HQ values at Ishkoman River, except for Mn, Pb, and Zn Downstream of Ghizer River, and Sb in Yasin River of GRB. Results revealed that children were noted with higher risk than adults (Figure 4(a) and 4(b)). Higher HQ values of As, Sb, Cd, and Ni than other PHE were attributed to their high toxicity and low RfD values. This study noted children are at higher risk due to their vulnerability and low body weight than adults (Ullah et al. 2019). Higher HQ values of children were in support of the previous study (Emmanuel et al. 2022). The HQ values of GRB were noted as lesser than that of Naltar Lakes in the vicinity (Muhammad 2023).
Figure 4
Hazard quotient values of (a) children and (b) adults through water consumption in the Ghizer River Basin.
View largeDownload slide

Hazard quotient values of (a) children and (b) adults through water consumption in the Ghizer River Basin.

Figure 4
Hazard quotient values of (a) children and (b) adults through water consumption in the Ghizer River Basin.
View largeDownload slide

Hazard quotient values of (a) children and (b) adults through water consumption in the Ghizer River Basin.

Close modal

Cancer risk

Listen
The CR values via PHE consumption in the water samples of the GRB were summarized for adults (Figure 5). The uppermost CR value of 0.39E-04 for As through consumption was noted for the water samples collected at the Ishkomen River. The Ishkomen River showed higher CR values than other segments of the GRB. Higher CR values of the Ishkomen River were due to maximum As contamination in water. CR values through water consumption of GRB were noted under the USEPA thresholds. CR values through water consumption of GRB were noted in previous study by Muhammad et al. (2010) Indus River, Pakistan. This study has limitation of collecting epidemiological data in the GRB and its correlation with the health risk assessment indices.
Figure 5
Cancer risk index values (1E-04) through water consumption for adults in the Ghizer River Basin.
View largeDownload slide

Cancer risk index values (1E-04) through water consumption for adults in the Ghizer River Basin.

Figure 5
Cancer risk index values (1E-04) through water consumption for adults in the Ghizer River Basin.
View largeDownload slide

Cancer risk index values (1E-04) through water consumption for adults in the Ghizer River Basin.

Close modal

Statistical analysis

Listen

The PC was used to identify the inter-element correlation among the water samples in the GRB and is summarized in Table 3. Among inter-element correlation, various elements such as the Cu–Mn, Cu–Cr, Cu–Co, Cu–Ni, Cu––Pb, Mn–Cr, Mn–Co, Mn–Ni, Mn–Zn, Mn–Pb, Cr–Co, Cr–Ni, Cr–Pb, Co–Ni, Co–Pb, Co–Zn, Ni–Pb, and Zn–Pb in the GRB showed significant correlation (>0.7, Table 3). Few of these PHE showed negative and strong negative correlations. The significant correlation between these elemental pairs proposed their common lithogenic sources. The results of PC were further supported using PCA.

Table 3

Inter-metal correlation of PHE in the water samples of the Ghizer River Basin, northern Pakistan

PHEAsCuMnCrCoNiSbZnCdPb
As 1.00          
Cu 0.33 1.00         
Mn 0.44* 0.91** 1.00        
Cr 0.38** 0.87** 0.74** 1.00       
Co 0.46** 0.95** 0.96** 0.87** 1.00      
Ni 0.40** 0.90** 0.86** 0.97** 0.94** 1.00     
Sb −0.42** −0.14 −0.31 −0.19 −0.31 −0.24 1.00    
Zn 0.52** 0.64** 0.77** 0.44** 0.76** 0.57** −0.26** 1.00   
Cd 0.28 0.13 0.15 0.07 0.16 0.10 −0.05 0.21 1.00  
Pb 0.62** 0.77** 0.84** 0.715** 0.88** 0.80** −0.25** 0.83** 0.26 1.00 
PHEAsCuMnCrCoNiSbZnCdPb
As 1.00          
Cu 0.33 1.00         
Mn 0.44* 0.91** 1.00        
Cr 0.38** 0.87** 0.74** 1.00       
Co 0.46** 0.95** 0.96** 0.87** 1.00      
Ni 0.40** 0.90** 0.86** 0.97** 0.94** 1.00     
Sb −0.42** −0.14 −0.31 −0.19 −0.31 −0.24 1.00    
Zn 0.52** 0.64** 0.77** 0.44** 0.76** 0.57** −0.26** 1.00   
Cd 0.28 0.13 0.15 0.07 0.16 0.10 −0.05 0.21 1.00  
Pb 0.62** 0.77** 0.84** 0.715** 0.88** 0.80** −0.25** 0.83** 0.26 1.00 

*Correlation is significant at the 0.05 level (two-tailed).

**Correlation is significant at the 0.01 level (two-tailed).

View Large

The PCA technique was used to factorize the PHE on the basis of their concentration/loading in the water of the GRB. The PHE concentration data were used in the rotational component matrixes of PCA and are summarized in Figure 6. PCA extracted a total cumulative variance of 81.45% for PHE water data in the GRB and classified it into following factors. Factor 1 (lithogenic factor) shared 68.92% of the cumulative factorization with high loadings of PHE such as Cd, Cr, Co, Cu, Mn, Ni, Pb, and Zn. Higher loading PHE in Factor 1 could be attributed to mafic-ultramafic rocks of KIA and mineralized metamorphic zones (Kazmi & Jan 1997). Factor 2 ‘mixed factor’ contributed 12.53% to the total cumulative variance of PCA results for the water samples of the GRB with higher loading of As and Sb, suggesting input from the agrogenic activities and lithology along with the GRB. The results of statistical analyses for provenance PHE such as Cr, Ni, and Co in the water samples of the GRB were consistent with a previous study by Muhammad & Ahmad (2020). The consistency in a significant correlation of these associated PHE was due to their enrichment in bedrocks of MKT and KIA.
Figure 6
Factor loading for selected PHEs in water samples of the Ghizer River Basin.
View largeDownload slide

Factor loading for selected PHEs in water samples of the Ghizer River Basin.

Figure 6
Factor loading for selected PHEs in water samples of the Ghizer River Basin.
View largeDownload slide

Factor loading for selected PHEs in water samples of the Ghizer River Basin.

Close modal
Listen

This study concluded that the maximum concentration among PHE was noted for Mn and the minimum for Sb and Co. The majority of the PHE was observed to be higher in the Ishkomen River of the GRB. PHE studied in the water samples of the GRB were found to be within the WHO drinking water threshold standards, except for Ni. For non-cancer risk, higher values of CDI were observed for Mn and HQ for As, followed by Sb. Non-cancer and cancer risk values were found to be within the USEPA thresholds. Geospatial analysis revealed higher levels of contamination for a majority of PHE at Ishkomen River and downstream of Ghizer River of the GRB. Statistical analyses showed that PHE contamination in the water samples of the GRB was mainly attributed to lithogenic processes rather than agrogenic activities. This study provides baseline information that will help the management in assessing the quality of the GRB and help in its conservation. This study recommends future studies on the temporal variation of PHE in each season of the year. PHE speciation in water and sediment and their correlation along with epidemiological data in the GRB is further recommended for future studies.

Listen

Financial support of the Higher Education Commission, Pakistan for project Ref # 20-17208/NRPU/R&D/HEC/2021 is highly acknowledged.

Listen

A.U.H did data curation and wrote the draft; S.M. conceptualized the study, acquired funds, performed methodology, did project administration, collected resources, did software analysis, supervised, wrote, reviewed, and edited the manuscript; C.T. wrote, reviewed, and edited the manuscript,

Listen

All authors reviewed and approved the final manuscript.

Listen

All authors approved for this publication.

Listen

All relevant data are included in the paper or its Supplementary Information.

Listen

The authors declare there is no conflict.

Abd-Elaty
I.
,
Saleh
O. K.
,
Ghanayem
H. M.
,
Zeleňáková
M.
 &
Kuriqi
A.
2022
Numerical assessment of riverbank filtration using gravel back filter to improve water quality in arid regions
.
Frontiers in Earth Science
10
,
1006930
.
Google Scholar
Crossref
Search ADS
 
Alarcón-Herrera
M. T.
,
Martin-Alarcon
D. A.
,
Gutiérrez
M.
,
Reynoso-Cuevas
L.
,
Martín-Domínguez
A.
,
Olmos-Márquez
M. A.
 &
Bundschuh
J.
2020
Co-occurrence, possible origin, and health-risk assessment of arsenic and fluoride in drinking water sources in Mexico: geographical data visualization
.
Science of the Total Environment
698
,
134168
.
Google Scholar
Crossref
Search ADS
PubMed
 
Ali
W.
 &
Muhammad
S.
2023
Spatial distribution, eco-environmental risks, and source characterization of heavy metals using compositional data analysis in riverine sediments of a Himalayan river, Northern Pakistan
.
Journal of Soils and Sediments
23
,
2244
–
2257
.
Google Scholar
Crossref
Search ADS
 
Ali
M. M.
,
Rahman
S.
,
Islam
M. S.
,
Rakib
M. R. J.
,
Hossen
S.
,
Rahman
M. Z.
,
Kormoker
T.
,
Idris
A. M.
 &
Phoungthong
K.
2022
Distribution of heavy metals in water and sediment of an urban river in a developing country: a probabilistic risk assessment
.
International Journal of Sediment Research
37
,
173
–
187
.
Google Scholar
Crossref
Search ADS
 
Arif
M.
2000
Zincian, manganiferous chrome spinel from the Swat valley ophiolite, NW Pakistan
.
Geological Bulletin University of Peshawar
33
,
103
–
110
.
Google Scholar
 
Ayejoto
D. A.
,
Agbasi
J. C.
,
Egbueri
J. C.
 &
Abba
S. I.
2023
Evaluation of oral and dermal health risk exposures of contaminants in groundwater resources for nine age groups in two densely populated districts, Nigeria
.
Heliyon
9
,
4
,
e15483
.
Google Scholar
Crossref
Search ADS
PubMed
 
Bhat
N. A.
,
Ghosh
P.
,
Ahmed
W.
,
Naaz
F.
 &
Darshinee
A. P.
2023
Heavy metal contamination in soils and stream water in Tungabhadra basin, Karnataka: environmental and health risk assessment
.
International Journal of Environmental Science and Technology
20
,
3071
–
3084
.
Google Scholar
Crossref
Search ADS
 
Chelyadina
N. S.
,
Kapranov
S. V.
,
Popov
M. A.
,
Smirnova
L. L.
 &
Bobko
N. I.
2023
The mussel Mytilus galloprovincialis (Crimea, Black Sea) as a source of essential trace elements in human nutrition
.
Biological Trace Element Research.
https://doi.org/10.1007/s12011-023-03607-1
.
Google Scholar
 
Chibuike
A.
,
Alu
M. O.
,
Anih
C. B.
 &
Obasi
P. N.
2023
Ecological impact and human health risk assessment of pumpkin and spinach cultivated around non-mining axes of Ebonyi State
.
Petrochemical Industries Intern
6
,
49
–
63
.
Google Scholar
 
Din
I. U.
,
Muhammad
S.
,
Faisal
S.
 &
Ali
W.
2023
Heavy metal (loid)s contamination and potential risk assessment via groundwater consumption in the district of Hangu, Pakistan
.
Environmental Science and Pollution Research
30
,
33808
–
33818
.
Google Scholar
Crossref
Search ADS
PubMed
 
Fallah
S. H.
,
Bakaeian
M.
,
Parsian
H.
,
Amouei
A.
,
Asgharnia
H.
,
Ghanbarian
M.
,
Mousapour
A.
,
Tabarinai
H.
,
Oskoei
V.
 &
Miri
S. A.
2022
Potentially harmful heavy metal contamination in Babolrood river: evaluation for risk assessment in the Mazandaran province, Iran
.
International Journal of Environmental Analytical Chemistry
102
,
7209
–
7223
.
Google Scholar
Crossref
Search ADS
 
Haque
M. R.
,
Ali
M. M.
,
Ahmed
W.
 &
Rahman
M. M.
2022
Assessment of metal (loid) s pollution in water and sediment from an urban river in Bangladesh: an ecological and health risk appraisals
.
Case Studies in Chemical and Environmental Engineering
6
,
100272
.
Google Scholar
Crossref
Search ADS
 
Hassan
R. O.
,
Othman
H. O.
,
Ali
D. S.
,
Abdullah
F. O.
 &
Darwesh
D. A.
2023
Assessment of the health risk posed by toxic metals in commonly consumed legume brands in Erbil, Iraq
.
Journal of Food Composition and Analysis
120
,
105282
.
Google Scholar
Crossref
Search ADS
 
Heerspink
B. P.
,
Kendall
A. D.
,
Coe
M. T.
 &
Hyndman
D. W.
2020
Trends in streamflow, evapotranspiration, and groundwater storage across the Amazon basin linked to changing precipitation and land cover
.
Journal of Hydrology: Regional Studies
32
,
100755
.
Google Scholar
 
Hinrichsen
D.
 &
Tacio
H.
2002
The coming freshwater crisis is already here
. In:
The Linkages Between Population and Water
.
Woodrow Wilson International Center for Scholars
,
Washington, DC
, pp.
1
–
26
.
Google Scholar
 
Idrees
M.
,
Jan
F. A.
,
Ara
A.
,
Begum
Z. M.
,
Mahmood
M.
 &
Gulab
H.
2017
Analysis and human health risk from selected heavy metals in water, sediments and freshwater fish (Labeo Rohita, Cyprinus Carpio, Glyptothorax Punjabensis) collected from three rivers in district Charsadda, Khyber-Pakhtunkhwa, Pakistan
.
Carpathian Journal of Earth And Environmental Sciences
12
,
641
–
648
.
Google Scholar
 
Iordache
A. M.
,
Nechita
C.
,
Zgavarogea
R.
,
Voica
C.
,
Varlam
M.
 &
Ionete
R. E.
2022
Accumulation and ecotoxicological risk assessment of heavy metals in surface sediments of the Olt River, Romania
.
Scientific Reports
12
,
880
.
Google Scholar
Crossref
Search ADS
PubMed
 
Ismail
W. N. A. T.
,
Amin
A.
,
Kamarudin
M. K. A.
,
Ibrahim
A.
 &
Salleh
N. S. N. M.
2023
Community concerns of river pollution spatial model using geographic information system (GIS) in Ibai River, Terengganu
.
Planning Malaysia
21
.
https://doi.org/10.21837/pm.v21i25.1226
.
Google Scholar
 
Ismanto
A.
,
Hadibarata
T.
,
Widada
S.
,
Indrayanti
E.
,
Ismunarti
D. H.
,
Safinatunnajah
N.
,
Kusumastuti
W.
,
Dwiningsih
Y.
 &
Alkahtani
J.
2023
Groundwater contamination status in Malaysia: level of heavy metal, source, health impact, and remediation technologies
.
Bioprocess and Biosystems Engineering
46
,
467
–
482
.
Google Scholar
Crossref
Search ADS
PubMed
 
Jagoutz
O.
 &
Schmidt
M.
2013
The nature and composition of the crustal delaminate in arcs
.
Earth and Planetary Science Letters
371
,
177
–
190
.
Google Scholar
 
Kavcar
P.
,
Sofuoglu
A.
 &
Sofuoglu
S. C.
2009
A health risk assessment for exposure to trace metals via drinking water ingestion pathway
.
International Journal of Hygiene and Environmental Health
212
,
216
–
227
.
Google Scholar
Crossref
Search ADS
PubMed
 
Kazmi
A. H.
 &
Jan
M. Q.
1997
Geology and Tectonics of Pakistan
.
Graphic publishers
.
Google Scholar
 
Khafaji
M. S. A.
,
Alwan
I. A.
,
Khalaf
A. G.
,
Bhat
S. A.
 &
Kuriqi
A.
2022
Potential use of groundwater for irrigation purposes in the Middle Euphrates region, Iraq
.
Sustainable Water Resources Management
8
,
157
.
Google Scholar
Crossref
Search ADS
 
Khan
K.
,
Lu
Y.
,
Khan
H.
,
Zakir
S.
,
Khan
S.
,
Khan
A. A.
,
Wei
L.
 &
Wang
T.
2013
Health risks associated with heavy metals in the drinking water of Swat, northern Pakistan
.
Journal of Environmental Sciences
25
,
2003
–
2013
.
Google Scholar
Crossref
Search ADS
 
Kumar
R.
,
Qureshi
M.
,
Vishwakarma
D. K.
,
Al-Ansari
N.
,
Kuriqi
A.
,
Elbeltagi
A.
 &
Saraswat
A.
2022
A review on emerging water contaminants and the application of sustainable removal technologies
.
Case Studies in Chemical and Environmental Engineering
6
,
100219
.
Google Scholar
Crossref
Search ADS
 
Lee
X. J.
,
Ong
H. C.
,
Ooi
J.
,
Yu
K. L.
,
Tham
T. C.
,
Chen
W.-H.
 &
Ok
Y. S.
2022
Engineered macroalgal and microalgal adsorbents: synthesis routes and adsorptive performance on hazardous water contaminants
.
Journal of Hazardous Materials
423
,
126921
.
Google Scholar
Crossref
Search ADS
PubMed
 
Luo
P.
,
Xu
C.
,
Kang
S.
,
Huo
A.
,
Lyu
J.
,
Zhou
M.
 &
Nover
D.
2021
Heavy metals in water and surface sediments of the Fenghe River Basin, China: assessment and source analysis
.
Water Science and Technology
84
,
3072
–
3090
.
Google Scholar
Crossref
Search ADS
PubMed
 
Muhammad
S.
,
Ali
W.
 &
Rehman
I.
2022
Potentially Harmful Elements Accumulation and Health Risk Assessment of Edible Fish Tissues Caught from the Phander Valley, Northern Pakistan
.
Biological Trace Element Research
200
,
4837
–
4845
.
Google Scholar
Crossref
Search ADS
PubMed
 
Muhammad
S.
,
Ullah
S.
,
Ali
W.
,
Jadoon
I. A. K.
 &
Arif
M.
2022
Spatial distribution of heavy metal and risk indices of water and sediments in the Kunhar River and its tributaries
.
Geocarto International
37
,
5985
–
6003
.
Google Scholar
Crossref
Search ADS
 
Nivesh
S.
,
Patil
J. P.
,
Goyal
V. C.
,
Saran
B.
,
Singh
A. K.
,
Raizada
A.
,
Malik
A.
 &
Kuriqi
A.
2023
Assessment of future water demand and supply using WEAP model in Dhasan River Basin, Madhya Pradesh, India
.
Environmental Science and Pollution Research
30
,
27289
–
27302
.
Google Scholar
Crossref
Search ADS
PubMed
 
Pace
C.
,
Fencl
A.
,
Baehner
L.
,
Lukacs
H.
,
Cushing
L. J.
 &
Morello-Frosch
R.
2022
The drinking water tool: a community-driven data visualization tool for policy implementation
.
International Journal of Environmental Research and Public Health
19
,
1419
.
Google Scholar
Crossref
Search ADS
PubMed
 
Reyhani
P.
,
Ansari
M. R.
,
Saeb
K.
 &
Tonekabon
I.
2013
Assessment of heavy metals contamination in surface water of the upstream Sardabrud River, North of Iran
.
Life Science Journal
10
,
7s
,
884
–
892
.
Google Scholar
 
Saddique
U.
,
Muhammad
S.
,
Tariq
M.
,
Zhang
H.
,
Arif
M.
,
Jadoon
I. A.
 &
Khattak
N. U.
2018
Potentially toxic elements in soil of the Khyber Pakhtunkhwa province and Tribal areas, Pakistan: Evaluation for human and ecological risk assessment
.
Environmental Geochemistry and Health
40
,
2177
–
2190
.
Google Scholar
Crossref
Search ADS
PubMed
 
Schwantes
D.
,
Junior
A. C. G.
,
Manfrin
J.
,
Campagnolo
M. A.
,
Zimmermann
J.
,
Junior
E. C.
 &
Bertoldo
D. C.
2021
Distribution of heavy metals in sediments and their bioaccumulation on benthic macroinvertebrates in a tropical Brazilian watershed
.
Ecological Engineering
163
,
106194
.
Google Scholar
Crossref
Search ADS
 
Selvam
S.
,
Jesuraja
K.
,
Roy
P. D.
,
Venkatramanan
S.
,
Khan
R.
,
Shukla
S.
,
Manimaran
D.
 &
Muthukumar
P.
2022
Human health risk assessment of heavy metal and pathogenic contamination in surface water of the Punnakayal estuary, South India
.
Chemosphere
298
,
134027
.
Google Scholar
Crossref
Search ADS
PubMed
 
Setia
R.
,
Dhaliwal
S. S.
,
Kumar
V.
,
Singh
R.
,
Kukal
S. S.
 &
Pateriya
B.
2020
Impact assessment of metal contamination in surface water of Sutlej River (India) on human health risks
.
Environmental Pollution
265
,
114907
.
Google Scholar
Crossref
Search ADS
PubMed
 
USEPA
1999
Environmental Protection Agency of United States: Guidance for Performing Aggregate Exposure and Risk Assessments
.
USEPA
2005
Guidelines for Carcinogen Risk Assessment
.
Risk Assessment Forum
,
Washington, DC
.
EPA/630/P-03/001F
.
USEPA
2010
IRIS Chemical Assessment Survey on Arsenic
.
US Environmental Protection Agency (USEPA)
.
USEPA
2011
Exposure Factors Handbook
.
United States Environmental Protection Agency
,
Washington, DC
.
(EPA/600/R-09/052F)
.
WHO
2011
World Health Organization Guidelines for Drinking Water Quality
. 4th edn.
Recommendations III
.
Williams
S. A.
,
Eden
S.
,
Megdal
S. B.
 &
Joe-Gaddy
V.
2023
Diversity, equity, inclusion, and justice in water dialogues: a review and conceptualization
.
Journal of Contemporary Water Research & Education
177
,
113
–
139
.
Google Scholar
Crossref
Search ADS
 
Xiao
H.
,
Shahab
A.
,
Xi
B.
,
Chang
Q.
,
You
S.
,
Li
J.
,
Sun
X.
,
Huang
H.
 &
Li
X.
2021
Heavy metal pollution, ecological risk, spatial distribution, and source identification in sediments of the Lijiang River, China
.
Environmental Pollution
269
,
116189
.
Google Scholar
Crossref
Search ADS
PubMed
 
Xie
F.
,
Yu
M.
,
Yuan
Q.
,
Meng
Y.
,
Qie
Y.
,
Shang
Z.
,
Luan
F.
 &
Zhang
D.
2022
Spatial distribution, pollution assessment, and source identification of heavy metals in the Yellow River
.
Journal of Hazardous Materials
436
,
129309
.
Google Scholar
Crossref
Search ADS
PubMed
 
Zhang
J.
,
Mauzerall
D. L.
,
Zhu
T.
,
Liang
S.
,
Ezzati
M.
 &
Remais
J. V.
2010
Environmental health in China: progress towards clean air and safe water
.
The Lancet
375
,
1110
–
1119
.
Google Scholar
Crossref
Search ADS
 
© 2023 The Authors
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licence (CC BY 4.0), which permits copying, adaptation and redistribution, provided the original work is properly cited (http://creativecommons.org/licenses/by/4.0/).