The study's observations on water quality were compared with the National Environmental Standards and Regulation Enforcement Agency (NESREA) and World Health Organization (WHO) (2011) acceptable levels in the guidelines for drinking water.
Physical parameters of the water
The results of the appearance are presented in Table 3 and Fig. 3, which show that the water is not clean. This is an indication that the water has impurities. Table 3 shows that the water has a taste and odor, which indicates the presence of dissolved gases, inorganic chemicals, and organic components. This difference may be from domestic, natural or agricultural sources. The analysis revealed that the color of the water had a mean value of 51 Hazen, which is above the NESREA standard of 15 Hazen. This is due to pollutants from artisanal mining around the ponds, as well as decomposing organic waste (vegetation) or inorganic matter (rocks or soil). Binnie, Kimber and Thomas (2018) stated that the physical characteristics of water are impacted by the presence of suspended solids and physical pollutants such as dirt, silt, clay, or organic matter. These compounds may impact odor, color, and turbidity. One major class of physical pollutants is suspended solids, which include dirt, dust, silt, clay, algae, and any undissolved particles larger than 2 mm. In addition to causing color and turbidity, suspended solids in water can harbor infections and other contaminants hazardous to human health (CDC, 2020).
Table 3
Physical parameters of the water
| Parameter | Barkin Ladi | Jos South | Bokkos | Mean Value | NESREA (Permissible Limit) | WHO (Permissible Limit) |
| Appearance | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable |
| Taste | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable |
| Odor | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable | Unobjectionable |
| Color | 50 | 52 | 52 | 51 | 15 | - |
| Temperature | 27.3 | 25.1 | 27.4 | 26.6 | 25-30oC | 25-30oC |
| Turbidity | 7 | 12 | 13 | 10.7 | 0–5 | 5.0 |
| Electric Conductivity | 1008 | 1007 | 1017 | 1010 | 1000 | 1000 |
One of the most important physicochemical factors for determining the quality of water for human consumption is temperature. It also affects a variety of activities in waterbodies, including the rate at which chemical reactions occur, the solubility of gases, and the amplification of tastes and colors in the water (WHO, 2008). The mean temperature was 26.60°C (Table 3), which shows that the water temperature observed during the period of study was within the standard permissible limits of the WHO (2011) and NESREA. The results obtained from the mining ponds were similar to those of Kazi et al. (2009), who recorded water temperatures ranging from 26–310°C from surface waterbodies in Nigeria.
The mean turbidity value of 10.7Ntu obtained from Table 3 in this study was greater than the recommended standard for both the NESREA and the WHO. High turbidity levels signify increased concentrations of silt, clay, and organic elements inside the ponds. However, higher values might be a sign of particulate matter, such as clay or silt; organic matter that has broken down; and other pollutants that have lowered water transparency and are caused by artisanal miners' ongoing illicit mining operations in the vicinity. Turbidity levels increase due to runoff into several open ponds carrying impurities (Mafuyai et al., 2019). A high turbidity indicates how well germs are filtered out. Nonetheless, a high level of turbidity could be the source of the bacteria. Moreover, viruses can cause harmful effects when turbidity levels are high (Shah, Arjunan, Baroutaji and Zakharova, 2023). These results further corroborate the findings of Garba et al. (2019) that the turbidity level found in every sample of water taken in Jos is greater than what Nigeria's water quality regulations allow.
The samples analyzed in the study area had a mean electrical conductivity of 1010 µS/cm (Table 3). This value is above the maximum permissible limit set by the WHO and NESREA standards (1000 µS/cm). Electrical conductivity (EC) measures how well a sample of water can carry or conduct electrical currents. A high conductivity indicates a high pollutant content, which has a profound effect on taste and, in turn, influences the user's acceptance of the water. The conductivity increases with temperature and salinity, which may be detrimental to the quality of the water. This is because the more contaminants (dissolved materials, chemicals, and minerals) are present in the water, the higher the conductivity. These findings corroborate the findings of Emumejaye and Daniel (2015) in Oleh, Delta State and Gongden and Lohdip (2015) in the Nagani/Wubang Dam in the Langtang South Plateau State, where they discovered that the electrical conductivity of water was greater.
Chemical parameters of water quality
The relevance of the hydrogen ion concentration (pH) in water is clear in the method by which it impacts chemical processes and biological activities that occur only within a restricted range. Table 4 shows that the pH of the water is 7, which is within the permissible limits of NESREA and the WHO (2011) (6.5–8.5). This is an indication that the water is neutral. Any readings below 7.0 are acidic, while those above 7.0 are alkaline. These findings are in agreement with those of Shittu, Olaitan and Amusa (2008), who reported a similar range of pH values for water used for drinking purposes in Abeokuta, Nigeria. A pH less than 6.5 is regarded as excessive acid for human consumption and may lead to acidosis. Additionally, low pH can exacerbate the toxicity of heavy metals in waterbodies.
Table 4
Chemical parameters of the water quality treatment
| Parameter | Barkin Ladi | Jos South | Bokkos | Mean Value | NESREA (Permissible Limit) | WHO (Permissible Limit) |
| pH | 7.6 | 6.9 | 6.5 | 7 | 6.5–8.5 | 6.5–8.5 |
| Total Hardness | 260 | 278 | 408 | 315 | 100–500 | 100–500 |
| Total Alkalinity | 197 | 189 | 154 | 180 | 20–200 | 20–250 |
| Fluoride (F) | 0.7 | 1 | 0.2 | 0.6 | 0.5–1.5 | 0.5–1.5 |
| Nitrate (NO3) | 47 | 23 | 39 | 36.3 | O-50 | 50 |
| Chloride (Cl) | 211 | 192 | 79 | 160.7 | 50–250 | 250 |
| Iron (Fe) | 1.1 | 0.2 | 0.2 | 0.5 | 0.1-03 | 0.1-3 |
| Manganese (Mn) | 0.001 | 0.001 | 0.1 | 0.03 | 0.01–0.3 | 0.1–0.4 |
| Sodium (Na) | 113 | 184 | 177 | 158 | 20–200 | 200 |
| Microbial | | | | | | |
| i. Total Coliform | 118 | 130 | 124 | 124 | 100 ml | 100 ml |
| ii. E. Coli | 124 | 135 | 112 | 123.7 | 100 ml | 100 ml |
The pH value range was 6.2–6.7 (6.40 0.11), indicating that the water was slightly acidic. Table 4 shows that the mean total hardness is 315 mg/l, which is within the permissible limits of the WHO and NESREA standards (100–500 mg/l). These findings agree with the results of Lawal, Lohdip and Egila (2014) for the Kampani mining river in Nigeria (317.3 mg/L). Although hard water does not present a health risk, using it for other household tasks constitutes a nuisance, such as household cleaning. These findings are similar to the results recorded by Ufodike, Kwanasie and Chude (2001) from Dokowa Mining Lake. Hardness is an important factor in lessening the negative effects of toxic substances. Water becomes more contaminated and harder as calcium and magnesium salts pollute it (Bhatt et al. 1999). Total hardness occurs when water contains a high amount of minerals. This is mainly caused by the presence of calcium and magnesium ions, which enter water from soil and rock.
The total alkalinity is a measure of the acid buffering capacity of water. It is the sum of the amounts of bicarbonates (HCO3–), carbonates (CO32–) and hydroxides (OH–) in water. As shown in Table 4, the total mean alkalinity was 180 mg/l in the study area. This value is within the stipulated permissible limits of the WHO and NESREA for drinking water. These findings agreed with the range documented by Moyle (2009) for natural waterbodies. The low alkalinity suggested that anthropogenic runoff and the catchment geology are the primary sources of natural alkalinity and that the alkalinity level is likely low for bicarbonate, hydroxide, and carbonate (Dhameja, 2012). Similarly, the mean concentration found in the mining ponds was 0.6 mg/l (Table 4), which is within the permissible limits of both the NESREA and WHO limits (0.5–1.5 mg/l). The fluoride comes from geologic sources. A minimum fluoride level is essential for good teeth. However, a greater quantity of water may cause pitting and staining in teeth, problems in both bones and joints and discoloration of teeth (Kausley, et al., 2019).
Conversely, the mean nitrate (NO3) concentration (36.3) was within the permissible limits of the WHO and NESREA (10–50 mg/l). The water nitrate content could be the result of surface runoff or leaching from nearby farm soils, indicating that farmers are using nitrogen fertilizer. Furthermore, defecation by miners and farmers along water banks may also affect the nitrogen content of water, which could contribute to the high BOD of mining pond water. Blue baby syndrome or methemoglobinemia may result from high levels of these viruses (CAWST, 2009). Additionally, the high consumption of nitrates by infants in water for an extended period of time without treatment may lead to death if not treated (Environment Agency (EA), 2019). Similarly, the mean chloride (Cl) concentration in Table 4 was 160.7 mg/l in the study area. The chloride concentrations in mine water are within the prescribed limits of the WHO and NESREA 50–250 mg/l. Studies show that kidney function may be affected by excessive chloride in water (CAWST, 2009).
Table 4 shows the amount of iron (Fe) recorded in the study area. A mean value of 0.5 mg/l was obtained from the mining ponds. These values are above the WHO and NESREA standards of 0.1-03 mg/l. Although iron is not directly thought to be harmful to water, it is a necessary component of nutrition and does not have any health-related recommendations (CAWST, 2009). A high quantity of water may cause taste complications (Gray, 1999). This finding agrees with the range documented by Garba et al. (2019), who reported a similar range for Fe in mining ponds around the University of Jos, Nigeria. Iron concentrations of 0.38–0.4 mg/l and 0.31 mg/l are higher than the maximum permissible level of 0.3 mg/l recorded from mining ponds and stream water, respectively.
Manganese is one of the three hazardous essential trace elements, and excessive concentrations of manganese in the human body can be harmful even if they are required for survival. Table 4 shows that the mean manganese (Mn) concentration was 0.03 mg/l. These findings are within the WHO and NESREA ranges of 0.1–0.4 mg/l and 0.01–0.3 mg/l, respectively. According to recent data, children who have high dissolved manganese concentrations have learning impairments (WHO, 2011). Nonetheless, deficiencies as well as excesses can have detrimental effects on people's health (CAWST, 2019). Manganese shortages can also have negative health impacts, such as altered hair color, birth abnormalities, and glucose intolerance. However, as shown in Table 4, sodium (Na+) has a mean value of 158 mg/l, which is within the permissible limits of 20–200 mg/l for portable water set by the WHO and NESREA. The burnt ashes that are washed and discharged into mining ponds may be the source of the Na + in the water. These findings are in agreement with those of Akpan-Idiok et al. (2012), who obtained a mean value of 34.2 mg/l from the Okpauku River in Nigeria.
Microbial parameters of water quality
Table 4 shows the microbial counts in the mining ponds. The total number of caliform bacteria had a mean value of 124 cfu, while the number of E. coli had a value of 123.7 cfu. These values are above the stipulated WHO and NESREA standards of 100 ml permissible limits. Rainfall-induced runoff from the environment, which can increase the microbial burden, particularly coliforms in water, is what causes high counts of bacteria. The main illnesses that can result from mining water being contaminated by bacteria include cholera, cramps, headaches, diarrhea, and typhoid. This study concurs with the findings of Doughari, Elmahmood and Manzara (2007) and Ouma, Ngeranwa, Juma and Mburu (2016). The abnormally high total heterotrophic bacterial load in the water indicated the presence of possibly harmful microorganisms.
The higher pH and increased amounts of biodegradable organics in the waterbody observed during the dry season may also have contributed to the high microbial load by promoting the growth of the microbial population. These findings coincide with the reports of Shittu Olaitan and Amusa (2008) and Abednego, Mbaruk, John, and John (2013), who recorded a high total coliform count exceeding the permissible limit of the WHO from water sources in the Ogun River. The presence of these bacterial species in the water samples may have been caused by farming practices and the activities of the inhabitants leaving near ponds. Open defecation around farmlands increases the likelihood that runoff from these farms will end up in the river. Furthermore, excessive runoff may increase the microbiological load that rainfall carries into the soil, and soil leaching through rain brings additional nutrients (Esharegoma et al. 2018).
Heavy metal parameters and water quality
Cadmium is a naturally occurring metal that is typically found in the environment in combination with other elements as a mineral (Aboujassoum, and Ozeas, 2012). Groundwater and surface water can receive their supply of Cd from geologic deposits, particularly when they contact soft, acidic waters (Shuaibu, et al., 2014). Table 5 shows that the mean cadmium (Cd) concentration in the study area was 0.002 mg/l, which is within the permissible limit (0.23) of the WHO and NESREA. An excessive amount of cadmium can cause renal damage, osteoporosis, carcinogenesis, and issues related to development and reproduction (Aboujassoum, and Ozeas, 2012; Shuaibu, et al., 2014; Kausley et al., 2019).
Table 5
Heavy metal parameters of water quality
| Parameter | Barkin Ladi | Jos South | Bokkos | Mean Value | NESREA (Permissible Limit) | WHO (Permissible Limit) |
| Cadmium (Cd) | 0.002 | 0.001 | 0.002 | 0.002 | 0.003 | 0.003 |
| Cobalt (Co) | 0.04 | 0.02 | 0.01 | 0.02 | 0.05 | 0.05 |
| Nickel (Ni) | 0.01 | 0.001 | 0.02 | 0.01 | 0.02 | 0.02 |
| Lead (Pb) | 0.02 | 0.02 | 0.01 | 0.02 | 0.01 | 0.01 |
| Zinc (Zn) | 2.8 | 2.3 | 1.2 | 2.1 | 1–3 | 1–3 |
| Copper (Cu) | 1.2 | 1.07 | 0.05 | 0.8 | 0.05-1 | 2 |
| Chromium (Cr) | 0.12 | 1.02 | 0.3 | 0.5 | 0.05 | 0.05 |
| Arsenic (As) | 0.002 | 0.002 | 0.1 | 0.03 | 0.1–0.2 | 0.01 |
As shown in Table 5, cobalt (Co) had a mean value of 0.02 mg/l, which falls within the permissible level of 0.05 mg/l according to the WHO and NESREA. One element that is naturally present in water is cobalt. High concentrations resulting from absorption may have negative health consequences since vitamin B12 is a major cofactor of vitamin B12 and is essential for healthy brain and nervous system operation as well as blood production. It is among the most important transition metals for humans. On the other hand, consuming too much could be harmful to people. Furthermore, diarrhea, hypertension, heart disease, hemorrhage, lung disorders, goiter, thyroid damage, nausea, reproductive issues, hyperglycemia, hair loss, bone abnormalities, and mutations in living cells can all result from high amounts of cobalt exposure (Godiya, Cheng, Li, Chen and Lu, 2019; Saad, Alismaeel and Abbar, 2020).
Human health depends on the trace element nickel; however, excessive amounts of nickel can be harmful to the body. Because nickel (Ni) does not decompose in the environment, pollution from it is becoming a greater problem, especially in developing nations (Pechova, and Pavlata, 2007). The results in Table 5 show a mean value of 0.01 mg/l. This value is below the permissible limits of the WHO and NESREA standards. However, as a result of dissolving nickel ore, nickel may also be found in some groundwater. Numerous health problems, including contact dermatitis, heart disease, asthma, lung fibrosis, and respiratory tract cancer, are caused by high intake of this metal (Seilkop and Oller, 2003; Pechova, and Pavlata, 2007; Zambelli, Uversky and Ciurli, 2016; Chen, Brocato, Laulicht and Costa, 2017).
As shown in Table 5, the mean lead (Pb) concentration was 0.002 mg/l, which is higher than the permissible limits of 0.01 ppm according to the WHO and NESREA. It negatively impacts the nervous system, particularly for young children and expectant mothers (WHO, 2018). In infants and children, high concentrations may impede physical and mental development (CDC, 2020). A high concentration of lead in the body can be fatal or result in irreversible harm to the kidney, brain, and central nervous system. Typically, the damage results in behavioral and academic issues (such as hyperactivity), memory and concentration problems, high blood pressure, headache, slow growth, hearing problems, reproductive problems in men and women, joint pain and digestive problems (CAWST, 2009). These findings are in agreement with those of Shuaibu, Yinusa, Funtua and Akaangee (2014), who reported similar results: urine samples from people in Gwalameji, Bauchi, had the highest Pb concentration, 0.14 mg/l.
As shown in Table 5, zinc (Zn) had a mean value of 2.1 mg/l. This value is within the WHO and NESREA limits of 1–3 mg/l in both organizations. Because zinc is found naturally within the Earth’s crust, it can naturally find its way into water sources. For instance, strong rains can occasionally cause zinc to leach from natural sources (Sankhla, Kumari Nandan, Kumar and Agrawal, 2016). Similar values of this parameter were observed in Psurow ponds, where the value was below the WHO limit (Gaeka and IatkowskI, 2010). Table 5 shows a copper (Cu) mean value of 0.8 mg/l in the study area. This is within the permissible WHO (2.0) and NESREA (0.05-1 mg/l) levels in water. Copper can have an impact on the gastrointestinal system and is both a nutrient and a pollutant (CAWST, 2009). Liver and renal issues can result from prolonged exposure (Environment Agency (EA), 2019).
Table 5 shows that chromium (Cr) has a mean value of 0.5 mg/l. This is within the WHO and NESREA limits. Chromium is naturally found in the Earth's crust. Extreme exposure could lead to higher levels of accumulation in humans (Prasad, et al., 2021). It is an essential component that benefits individuals and is important for both regulating and reducing blood sugar levels (Pechova and Pavlata, 2007; Pechova and Pavlata, 2007; Liesch, Hinrichsen and Goldscheider, 2015). Similarly, the mean arsenic (AS) concentration was 0.03 mg/l. This value is above the limits permitted by both the WHO (0.01 mg/l) and the NESREA (0.1–0.2 mg/l). When consumed in excess of the allowable limit, arsenic is carcinogenic and can cause vascular illnesses; birth defects; and lung, bladder, kidney, and prostate cancers, among other conditions. Arsenic was first identified in the Agency for Toxic Substance and Disease Registry (ATSDR) substance priority list (Kausley, et al., 2019).