Evaluation and correlation study of heavy metals load in drinking water and update of water-related disease cases in Ebonyi State from

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1 AMERICAN JOURNAL OF SCIENTIFIC AND INDUSTRIAL RESEARCH 213, Science Huβ, ISSN: X, doi:1.5251/ajsir Evaluation and correlation study of heavy metals load in drinking water and update of water-related disease cases in Ebonyi State from J. N. Afiukwa Department of Industrial Chemistry, Ebonyi State University, P.M.B. 53, Abakaliki ABSTRACT Spectrophotometric and correlation analysis of heavy metal levels in drinking water was carried out. Samples from various sources of drinking water in different Local Government Areas in Ebonyi State were collected in pre-treated plastic bottles during the rainy and dry seasons and analysed for total Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn. Pearson s correlation analysis and t- Test statistics were used to evaluate the relationship between elevated heavy metal ions in the sample, while Integrated Disease Surveillance and Response System (IDRS) was used in epidemiological studies to evaluate the current status of four water-related disease cases in the area between 21 to 211. The result showed that the prevalence of guinea worm, diarrhoea and cholera monitored dropped by a 1 %, 15.3 % and 8.6 % respectively, while typhoid fever escalated by 71.6 % in 211 compared with the 21 data. The result also indicated elevated metal concentrations above the WHO guideline limits for drinking water in the order; Pb > Mn > Fe > Cr > Co > Cd > Ni in surface water and Mn > Pb > Cr > Co > Fe > Cd > Ni in groundwater samples. Seasonal variations were not significant (P >.5). The correlation analyses showed high degree of metal association in the order: Cu/Zn > Pb/Zn > Fe/Mn > Fe/Pb > Cd/Zn > Cu/Pb > Co/Fe > Cd/Co. Keywords: Drinking water, Heavy metals, Correlation, Pollution and Public Health. INTRODUCTION: Water-related disease cases such as cholera, typhoid fever, diarrhoea, guinea worm and dysentery regularly monitored and controlled in developed countries such as USA and China often manifest in many developing countries due to poor sanitation and lack of access to potable water (FMWR, 2; UNICEF, 21). The World Health Organization, WHO (1997) reported that about 8 % of ill-health in the Third World Countries is closely associated with polluted water and poor sanitation. In the past, many of the inhabitants of Ebonyi State who were solely dependent on surface water suffered the trauma of these diseases especially guinea worm infestation. By 1988 when the National Guinea worm Eradication Programme (NIGEP) was established, 653,62 cases were detected Nationwide with 5,879 endemic Villages (EVs) including Ebonyi State (Agosa, 27). The activities of NIGEP which included chemical abatement and the sinking of boreholes reduced incidence of these diseases to 95 EVs in 25. At that period, Ebonyi State ranked highest with 35 guinea worm cases, Benue (29) and Niger (22), (Agosa, 27). It is worrisome that in spite of all those efforts and in collaboration with the WHO, UNICEF and NGOs, cases of such disease conditions as hypertension, stroke, gastroenteritis, mental retardation and cancer are still rampant in this country. Epidemiological studies have also indicated a strong relationship between the occurrence of several diseases in humans, (particularly cardiovascular diseases, kidney-related disorders, neuro-cognitive effects and various forms of cancer) and the presence of heavy metals such as aluminium, cadmium, chromium and nickel (Al-Salah, 1996). Diarrhoea which is rampant in infants is strongly associated with arsenic, cadmium, chromium, copper, iron, mercury and zinc (Davis, 1977; Rollinson and Enig, 1981; Zang, 1987; UNEP/ILO/WHO, 1991; Jung et-al, 1993; Punnonen et-al, 1994; Taylor, 1996; Byron and Mechenich, 26 and Afiukwa, et-al, 29). Biological treatment of water has continued to receive the highest attention, but containment of heavy metal load in water is yet to receive the much desired attention. The aim of this study was to determine the levels of these heavy metals in drinking water, to evaluate a relationship between the metals and to monitor the

2 Am. J. Sci. Ind. Res., 213, 4(2): trend in the control of these prevailing water-related disease cases in Ebonyi State. MATERIALS AND METHODS: The concentrations of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were assessed using AAS (Perkin Elmer A Analyst 4 Model), while the status of water-borne disease cases from 21 to 211 were investigated through Integrated Disease Surveillance and Response system (IDSR). This method involved community-based disease case monitoring and surveillance, sampling and Laboratory analysis. Drinking water sources commonly used by the rural and urban communities comprising borehole, handdug well and spring as well as river, stream, pond, dam and tap water samples were collected from nine Local Government Areas in the State during the wet and dry seasons and used for the analysis. The samples were collected in pre-prepared well secured two litre plastic bottles and preserved in a.1m HNO 3 solution to immobilize and prevent possible lose of the metals through surface adsorption. Triplicate determinations of each sample were analyzed at the Nigerian National Petroleum Corporation (NNPC) Laboratory Warri, Delta State for Aluminium (Al), Manganese (Mn), Lead (Pb), Chromium (Cr), Cobalt (Co), Cadmium (Cd), Copper (Cu), Iron (Fe), Nickel (Ni) and Zinc (Zn). RESULTS AND DISCUSSION: The status of water-related disease cases in Ebonyi State from January, 21 to December, 211 is shown in Table 1 and the trend is presented in Fig.1. There was a 99.1% and 1 % reduction in the number of guinea worm cases reported in 28 (2 cases) and 211 () respectively when compared with the 21 data (224 cases). Cholera, Typhoid and diarrhoea, cases reduced by 93.1%, 47.1% 43.4% respectively in 28 but in 211, reported cases of cholera reduced by 8.6 % and diarrhoea, 15.3 % when compared with the 21 data while typhoid fever went up by 71.6 % against the same reference year. The trend in Guinea worm cases continued to show a downward trend down to a constant zero level up to 211. Cholera decreased from 118 in 23 to 66 cases in 24 representing 44 % reduction. Although it increased by 24.1% in 25 (87 cases), it also dropped reasonably by 62.1% from 25 to 26, 39.4% from 26 to 27, 93.1% reduction in 28 and 8.6 % in 211 surveillance report when compared with the 21 data. However, the reports shown here for cholera represent six months surveillance from July, 29 while the results of 21 and 211 were not confirmed in a standard laboratory. Typhoid and especially diarrhoea showed no gradient patterns as the trend remained undulating up to 211 records. The apparent lack of gradient patterns in these three disease cases apart from guinea worm suggests a non-point source of pollution and may be attributed to indiscriminate waste dumps in water bodies, poor sanitation and other uncontrolled anthropogenic sources of pollution. Elevated heavy metal toxicity identified in the study such as Cd, Cr and Fe (Table 2) may have contributed to the high prevalence status of diarrhoea cases often reported in the State. High amounts of nutrients such as nitrates and sulphates arising from fertilizer applications may also have caused uncontrolled diarrhoea cases (Hartman, 1983, Byron and Mechenich, 26 and Afiukwa, 29). Table 2 shows the mean concentrations of elevated total dissolved heavy metals in the water samples. The mean levels of Cu, Ni and Zn in all the samples fall within the WHO guideline limits with a range of -.32,.4 and.64 respectively between the seasons. The concentration of Al was not detected in the samples, while the mean concentrations of Cd, Co, Cr, Fe, Mn and Pb exceeded the WHO guideline limits. This result agrees with previous work on water quality assessment, (Afiukwa, 211). The status of these metals in ground and surface water supplies in the State in comparison with the WHO maximum acceptable limits are shown in Figs. 2 and 3 respectively. Table 1: Status of Water-related Disease Cases in Ebonyi State, Year /8 8/11 Diarrhoea 7, Cholera Typhoid Guinea worm *six months surveillance report, from July, 29; **Results not confirmed in standard Lab. 222

3 Cholera, Typhoid & Guinea Worm Disease Cases Diarrhoea Disease Cases Am. J. Sci. Ind. Res., 213, 4(2): Cholera Typhoid Guinea worm Diarrhoea Year 1 Fig. 1: Up-date of the status of water-related disease cases in Ebonyi State, Pearson s correlation analysis shown in Table 3 was used to determine the degree of metal association using Yongming s method as applied to the study of heavy metal contamination in urban dusts in China (Yongming et al, 26). The result indicated significant positive correlation between Cu/Zn, Fe/Mn, Pb/Zn, Cd/Zn, Cu/Pb, Fe/Pb and Cd/Co in the order presented across the Local Government Areas. The observed relationships suggest a common source of the metals. Chromium, which indicated negative correlation with the other metals, reflects a different source of the metal. The results of the t- Test evaluated at.5 confidence level also confirmed the above relationships in the order; Co/Ni > Cd/Co > Pb/Zn > Cd/Zn > Fe/Pb > Cu/Pb, Co/Fe. These relationships are possible with elements that share the same chemical environment or absorptive pathways. The presence of such metals in association affects the occurrence and absorption of the other or the toxicants may interact chemically to produce additive, synergistic or antagonistic effects. Simultaneous exposure of an organism to associated metal toxicants can be very traumatic if the associated metal toxicants interaction becomes synergistic. In such a case the toxicity of the combining minerals becomes additive to produce greater health risk. In antagonism, the toxicity of two or more chemical toxins in association is less than would be expected when the chemicals were administered separately. For example high level of zinc may induce deficiency of copper because it is believed that a high level of zinc inhibits copper absorption (Miroslav and Vladimir, 1999). High level of zinc is also known to antagonize Cd and Pb toxicities. Table 2: Mean concentrations (mg/l) of elevated metals in drinking water in Ebonyi State Groundwater >WHO Surface water >WHO WHO Metal N Mean + SD Range Limit N Mean + SD Range Limit(% limit (mg/l) (%) ) Cd Cr Fe Mn Pb Co mg/d N = Sample size, SD = Standard deviation 223

4 Sig. level Metal conc. (mg/l) Metal conc. (mg/l) Am. J. Sci. Ind. Res., 213, 4(2): WHO RS DS 1.8 WHO RS DS Metals Fig. Fig. 2: Mean 2: Concentration Mean concentration of Heavy Metals in of Groundwater heavy Samples metals in Ebonyi in State Fig. 3: Mean Concentration of Heavy Metals in Surface Water Samples in Ebonyi groundwater during the Rainy samples (RS) and during Dry Season the (DS) Rainy (RS) Fig. 3: Mean concentration of heavy metals in surface State during the Rainy (RS) and Dry Season (DS) and Dry (DS) seasons water samples during the Rainy (RS) and Dry (DS) seasons Table 3: Pearson s correlation matrix for the heavy metal concentrations in drinking water Metals Cd Co Cr Cu Fe Mn.553 Ni.96 Pb Zn Correlation Coeff. The left lower part is correlation coefficient; the right upper part is significant level (P<.5). Blank spaces represent relationships that are not correlated. CONCLUSION: This study have shown that some metal concentrations exceeded the WHO guideline limits for drinking water in the order: Pb > Mn > Fe > Cr > Co > Cd > Ni in surface water and Mn > Pb > Cr > Co > Fe > Cd > Ni in groundwater samples. Seasonal variations were however not significant (P >.5). The correlation analyses showed a high degree of metal association in the order: Cu/Zn > Pb/Zn > Fe/Mn > Fe/Pb > Cd/Zn > Cu/Pb > Co/Fe >Cd/Co REFERENCES: Afiukwa, J. N; Arua, S. N and Bekie, J. I (29). Heavy Metal Analysis of some Drinking Water sources and the status of Water-Related Disease Cases in Ebonyi State, Nigeria. Journal of Research in Physical Sciences 5(3):98-13 Afiukwa, J.N., (211).Evaluation of heavy metal pollution indices in some water supplies in Ebonyi State, Nigeria. J. Poll. Res. 3 (4): Al-Salah, I.A (1996). Trace Elements in Drinking Water Coolers collected from Primary Schools Riyadh, Saudi Arabia. Journal Science of the Total Environment, ELSEVIER 181:

5 Am. J. Sci. Ind. Res., 213, 4(2): Byron, S and Mechenich, C (26). Health Benefits and Toxicity of Common Metals and Minerials in Wisconsin Drinking Water Supplies, Water and Environmental Analysis Laboratory, College of Natural Resources UW Stevens Point/Centre for Watershed Science and Education, UW Extension pp Davis, P (1977). Fundamental Aspect of Pollution Control and Environmental Science 1 st Ed. The Trace Element Concentration of the Environment, Cheston pp.4, 125. FMWR, (2). National Water supply and sanitation policy, Federal Ministry for Water Resources (FMWR), Abuja Nigeria Hartman, P. E. (1983). Putative mutagens and carcinogens in foods. A review, Nitrate/Nitrite ingestion and gastric cancer mortality. J. Environmental Mutagen 5: p.111 Horton, R.K (1995). An Index Number System for Rating Water Quality. Journal of Water Pollution Control. Fed. 37 (3). Jung, K; Pergande, M; Graubaum, H.J; Fels, L.M; Endl, U and Stolte, H (1993). Urinary Protein and Enzymes as Early Indicators of Renal Dysfunction in Chronic Exposure to Cadmium. Journal of Clinical Chemistry Vol. 39: Miroslav, R and Vladimir, N.B (1999). Practical Environmental Analysis. Royal Society of Chemistry. U.K p.366 Punnonen, K; Irjala, K and Rajamaki, A (1994). Iron Deficiency Anaemia is Associated with High Concentration of Transferin Receptor in Serium. Journal of Clinical Chemistry Vol. 4: Rollinson, C. L and Enig, M.G (1981). Encyclopaedia of Chemical Technology. Kirth Othmer, 3 rd Ed. Vol.15 pp Taylor, A (1996). Detection and Monitoring for Disorders of Essential Trace Elements. Annals of Clinical Biochemistry Vol. 33: UNEP/ ILO/ WHO (1991). International Programme on Chemical Safety, Environmental Health Criteria 118, Inorganic Mercury, WHO Geneva UNICEF (21). Children s and Women s Rights in Nigeriaa Wake up call situation; Assessment and Analysis, UNICE, Nigeria, pp World Health Organization (WHO, 1997). Guidelines for Drinking Water Quality, 2 nd Ed. Vol.3. Surveillance and Control of Community Supplies, WHO Geneva Yongming, H; Peixuan, D.U; Junji, C and Posmentier, E.S (26). Multivariate Analysis of Heavy Metal Contamination in Urban Dusts in Xian, Central China. Journal Science of the Total Environment, ELSEVIER Vol. 355: Zang, Li (1987). Chromium in Drinking Water, Califonia Public Health Goal, Califonia p