Total coliforms, arsenic and cadmium exposure through drinking water in the Western Region of Ghana: application of multivariate statistical technique to groundwater quality

Abstract

In recent times, surface water resource in the Western Region of Ghana has been found to be inadequate in supply and polluted by various anthropogenic activities. As a result of these problems, the demand for groundwater by the human populations in the peri-urban communities for domestic, municipal and irrigation purposes has increased without prior knowledge of its water quality. Water samples were collected from 14 public hand-dug wells during the rainy season in 2013 and investigated for total coliforms, Escherichia coli, mercury (Hg), arsenic (As), cadmium (Cd) and physicochemical parameters. Multivariate statistical analysis of the dataset and a linear stoichiometric plot of major ions were applied to group the water samples and to identify the main factors and sources of contamination. Hierarchal cluster analysis revealed four clusters from the hydrochemical variables (R-mode) and three clusters in the case of water samples (Q-mode) after z score standardization. Principal component analysis after a varimax rotation of the dataset indicated that the four factors extracted explained 93.3 % of the total variance, which highlighted salinity, toxic elements and hardness pollution as the dominant factors affecting groundwater quality. Cation exchange, mineral dissolution and silicate weathering influenced groundwater quality. The ranking order of major ions was Na(+) > Ca(2+) > K(+) > Mg(2+) and Cl(-) > SO4 (2-) > HCO3 (-). Based on piper plot and the hydrogeology of the study area, sodium chloride (86 %), sodium hydrogen carbonate and sodium carbonate (14 %) water types were identified. Although E. coli were absent in the water samples, 36 % of the wells contained total coliforms (Enterobacter species) which exceeded the WHO guidelines limit of zero colony-forming unit (CFU)/100 mL of drinking water. With the exception of Hg, the concentration of As and Cd in 79 and 43 % of the water samples exceeded the WHO guideline limits of 10 and 3 μg/L for drinking water, respectively. Reported values in some areas in Nigeria, Malaysia and USA indicated that the maximum concentration of Cd was low and As was high in this study. Health risk assessment of Cd, As and Hg based on average daily dose, hazard quotient and cancer risk was determined. In conclusion, multiple natural processes and anthropogenic activities from non-point sources contributed significantly to groundwater salinization, hardness, toxic element and microbiological contamination of the study area. The outcome of this study can be used as a baseline data to prioritize areas for future sustainable development of public wells.

Review of Ghana’s water resources: the quality and management with particular focus on freshwater resources

“…Also, 6.14 to 7.50 pH units for pH, 48 to 240 mg/l for total alkalinity, 80.10 to 524 mg/l for TDS and 131 to 873 μS/cm for electrical conductivity. Affum et al (2015) reported toxic elements, hardness and salinity pollution as the main factors affecting the quality of groundwater. Mineral dissolution, cation exchange and silicate weathering influenced the quality of groundwater.…”

“…Affum et al (2015) reported the absence of E. coli in the water sampled, but wells contained total coliforms (Enterobacter species) that was 36%. All but one of the hand-dug wells and boreholes showed faecal contamination with levels above WHO and GSA guidelines.…”

Glebokie Lake in Szczecin after hydrotechnical regulations

“…In the assumption FA reduces contribution of less relevant variables obtained during the extraction of data by the PCA. The main difference between the PCA and FA is that the FA allows the expression of the measured values as a combination of factors and the equation includes a term, and thus obtained varifactors (factors after varimax rotation) may comprise previously unobservable hidden variables [18,20,30,31,35,36].…”

“…Chemometric procedures were often used for conducting studies on the quality of natural waters -including lake water [18][19][20][21][22][23][24]. Most of the works is a study of river waters in the catchment [25][26][27][28][29][30][31][32][33], as well as groundwater [34][35][36].…”

The Relationship between Total Income and Groundwater Utilization on Fluviomarine Landform Area in Jakarta

“…The higher the level of human activity in a place, the higher the level of household waste produced and if not properly managed, this can cause a decrease in groundwater quality (Takem et al, 2009;Bahar et al, 2010;Rani and Sasidhar, 2010;Akoteyon et al, 2011;Hastuti and Wardiha 2012;Strohschön et al, 2012;Affum et al, 2015). The sewage channel is the main cause of water contamination in Jakarta.…”