. 1 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 ReseaRch aRticle Effect of Drinking Water Hardness on Kidney Stones Formation in Ranya District Akram O. Esmail1*, Bahast A. Qadir2, Hawnaz Q. Hamad2 1Department of Soil and Water, College of Agriculture, Salahaddin University, Erbil, Iraq, 2Department of Biology, College of Sciences, Raparin University, Raparin-Sulaimani, Iraq ABSTRACT This study was conducted in Rania District, Raparin University, during September 2018–March 2019, to test the relation between water hardness and kidney stone formation. The investigation depended on questionnaire form which was distributed on 100 person in Raparin (Rania, Hajiawa, and Chwarqurna) and patients whom vested the Rania clinical during December 1, 2018–January 22, 2019 which were 238 patients and only 20 of them had kidney stones developing which represent 8.4% of the total kidney diseases. The results indicated to significant effect of gender at level of significant 5% on kidney stones formation, 10% of male, and 18% of female having kidney stones. The results of Chi-square test indicated to highly significant effect of age on kidney stone formation at level of significant (0.001). The kidney stone formation increased from 19.23% to 75% with an increase in age class from (14–34) to (54 or more) year. The negative correlation coefficient value of (r = −0.63*) was recorded between water hardness and stone risk index due to the high magnesium content of drinking water in the studied area. Keywords: Ca-hardness, component, Mg-hardness, stone risk index, total water hardness INTRODUCTION The urolithiasis regards as a very complex disease, many factors affecting on urinary calculus or formation of kidney stones.[1] Hard water means the water which contains more minerals in comparing with ordinary water. The most important ions are calcium and magnesium. Hardness is expressed in terms of calcium carbonate (CaCO 3 ) mg/l. The degree of hardness increases with increasing the concentration of calcium and magnesium in water if the concentration of them <75 m/l is considered as a soft water, 76–150 mg/l moderately hard, and more than 150 mg/l regards as a hard water.[2] Numerous studies were conducted in the Kurdistan region about water quality and its suitability for drinking purpose, most of them included total hardness, magnesium hardness, and calcium hardness water which directly related to kidney stones developing or forming or regards as one of the factors related to kidney stone formation in the world depending on type of water hardness and magnesium and bicarbonate concentration in drinking water.[1,3] Several factors increase the risk for kidney stones forming or developing which were summarized as inadequate water or fluid intake and dehydration, reduce in urinary volume, and increase in concentrations or levels of certain chemicals in urine such as calcium, oxalate, and uric acid to high level or decrease of magnesium to low level or too low and some medical conditions such as reflux and medullary sponge kidney urinary tract infections in additional to tubular acidosis. Anything that reduces or blocks the urine flow like urinary obstruction and genetic abnormalities also increase the risk of kidney stones developing.[4] Drinking water hardness in the Kurdistan region studied by numerous researchers as follow: The water harness in Sulaimani governorate the results indicated that the total hardness was ranged (from 110 to 280) mg CaCO 3 /l, it means most of the studied water hard and may have negative effect of kidney stone developing.[5] The water harness study of (Chaq–Chaq) Kliassan stream in Sulaimani city showed that the total hardness was ranged from 110 to 355 mg/l; it means most of studied water hard Corresponding Author: Akram Othman Esmail, Department of Soil and Water, College of Agriculture, Salahaddin University, Erbil, Iraq. E-mail: akram.esmail@su.edu.krd Received: Apr 14, 2019 Accepted: Apr 26, 2019 Published: Jan 20, 2020 DOI: 10.24086/cuesj.v4n1y2020.pp1-6 Copyright © 2020 Akram O. Esmail, Bahast A. Qadir, Hawnaz Q. Hamad. This is an open-access article distributed under the Creative Commons Attribution License. Cihan University-Erbil Scientific Journal (CUESJ) https://creativecommons.org/licenses/by-nc-nd/4.0/ https://creativecommons.org/licenses/by-nc-nd/4.0/ Esmail, et al.: Effect of drinking water hardness on kidney stones 2 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 to very hard and could have negative effect of kidney stone formation.[6] The water hardness of karees, springs, and streams in Erbil governorate was studied by Esmail,[7] the results explained that the total hardness was ranged from 151 to more than 1000 mg/l with a mean of 321 mg/l. It means most of the studied water was hard to very hard. The water hardness of Kapran near Erbil city was studied, the results indicated that the total hardness was ranged between 135.48 and 306.93 mg means must studied moderate hard to very hard.[8] The water hardness of springs at Halgwrd mountain was ranged between 93 and 122 mg/l CaCO 3 , it means that the water of this location is must soft water and suitable for drinking purpose depending on.[9,10] The water hardness in Erbil was ranged (138–446) mg CaCO 3 /l, it means most of the studied water was hard to very hard.[11] The value of total hardness of the water in Bator and Southwest and south Erbil was ranged between 173 and 900 mg CaCO 3 /l, this indicated that most studied water had hard to very hard class or not suitable for drinking purpose[9] or may have negative effect kidney stone developing.[8,12] The mean of total hardness, Ca-hardness, and Mg-hardness was (248.82–339.30), (207.49–291.21), and (41.34–97.57) mg/l, respectively, for drinking water in Halabja as mentioned by Schwart et al.[13] The studied water hardness in Dohuk governorate had the values ranged between 281 and 972 mg/l as CaCO 3 ; it means most of the studied water had hard to very hard class.[14] The water hardness of the studied water in Sulaimani governorate recorded the total hardness of (200–580) mg/l as CaCO 3 means; it refers to that the studied water has hard to very hard class and may have negative effect on kidney stone forming.[15] The inverse relationship was recorded between drinking water hardness and kidney stones developing (urolithiasis) for 2302 patients in various geographical regions of the united state.[16] The workers found the positive correlation between drinking water hardness and kidney stones forming and developing (urolithiasis) in 1000 general hospitals in the United States of America. On the other hand, the weak correlation was recorded between kidney stone-forming and drinking water hardness as mentioned by Churchill et al.[17] and Shuster et al.[18] The positive correlation was recorded between total water hardness and kidney stones forming in the United Kingdom, due to the water hardness values in South and East of England.[19] The relation between drinking water quality (hardness) and the stone risk index (SRI) (kidney stone forming) for 24 Provincial Capitals of Iran, was studied by Basiri et al.[1] The results indicated that the water hardness was ranged between 57 and 874 PPM; the SRI was ranged between 0.00 and 0.0198. The non-significant correlation was recorded between total water hardness of tap water and kidney stone formation, while the negative significant correlation was recorded between Mg-hardness and kidney stone formation with the correlation coefficient value of r = −0.51*. In the study conducted in Iran from 20 capital cites depending on large number of samples (21200) the negative significant correlation means increase in water hardness cased decrease in risk of kidney stone forming since 30% of total hardness is magnesium hardness which causes decrease in stone formation. Since the drinking water of the Kurdistan region is hard, especially the water of springs, wells, and rivers in Raparin District is hard to very hard which ranged from 150.46 to 1414.80 with the mean value of 337.71 mg/l as CaCO 3 . It means the water hardness of water in the Kurdistan region is above the recommended standard value of WHO.[9] For the above reasons, the aims of this investigation are to study the effect of: 1. Drinking water hardness on kidney stones developing or formation. 2. Amount of water intake per day, gender, age, and family history on developing kidney stones. MATERIALS AND METHODS For scientific research about the effect of drinking water hardness on kidney stones forming, the data were collected from December 1, 2018 to January 20, 2019 in one clinic of Rania city specialized in kidney diseases. The number of patients visited the mentioned clinic was 238 patients and only 20 of them had kidney stones developing or forming. The other source of data collecting was the distribution of questionnaire form on 100 persons (50 male and 50 female) inside and outside of Raparin University, which included (Hajyawa, Chwarqwrna, and Ranya), the questionnaire form was shown from Table 1 which prepared as mentioned from 20. The survey was conduct on water hardness in the Kurdistan region, while 52 water samples in Raparin District was depended in calculating risk index of stone formation. The water sample was analyzed from Raparin during 2018 by Dawson,[20] the total water hardness, magnesium hardness, and calcium hardness we determined according to following models and stone risk formation for 52 samples of water were calculate using following equation as mentioned by Basiri et al.[1] Stone risk index = SRI = [(Ca mg/l)/(Mg mg/l)]/ (bicarbonate (mg/l). Table 1: The questionnaire form Age Gender Male Female Source of drinking water Spring Well Amount of red meat eat High Medium Low Amount of water intake L/day 3–4 2–3 1–2 L/day Family history Yes No Esmail, et al.: Effect of drinking water hardness on kidney stones 3 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 Total hardness = [Ca mg/l*2.50+Mg mg/l*4.20]. Mg-hardness = (Mg mg/l*4.20). Ca-hardness = Total hardness−Mg-hardness. The statistical analysis was conduct using Chi-square test depend on the SPSS program version (22) and regression correlation curve was drown using Excel program. RESULTS As shown from Table 2, the gender affected significantly on kidney stones forming at level of significance (0.05), the statistical analysis indicated that the calculated Chi-square value (3.81) is more than tabulated value (3.50). The results indicated that 10% of male and 18% of female having kidney stones forming depending on total sample size (100). On the other hand, if the percentage was calculated separately for male and female, the percentage of samples having kidney stones forming was 20 and 30% for male and female, respectively. Table 3 indicates to the highly significant effect of age on kidney stone formation at the level of significant (0.001) with the calculated Chi-square value of 15.50. The kidney stone formation increased from 19.23% to 75% with increase in age. Table 4 indicates to the effect of source of drinking water on kidney stone was not significant in spite of the percentage of kidney stone in case of a source of drinking spring water was 20%, while the percentage was 29.415 in case of drinking well water. Table 5 explains that the amount of consumed meat per person had not affected significantly on kidney stones. Chi- square test refers to non-significant effect since the calculated Chi-square value (1.29) is less than tabulated value (3.40). Table 6 explains that the amount of drinking water (L/day/person) had not affected significantly on kidney stone formation. Chi-square test refers to non-significant effect since the calculated Chi-square value (1.290) is less than table value. Table 2: The effect of gender on kidney stone Gender Kidney stone Percentage of patients having kidney Have Have not From subsample From total (n=100) Male 10 40 20 10 Female 18 32 30 18 Total 28 72 28 Calculated Chi-square=3.81 Tab. Chi-square=3.50 P≥0.05 Table 3: Explains the effect of age on kidney stone Age (year) Have kidney stone Have not kidney stone Percentage of patients having kidney stone 14–34 16 67 19.23 34–54 9 4 69.23 54 or more 3 1 75.00 Calculated Chi-square value (X2)=15.50*** Tab. Chi-square=3.20 P≥0.001 Table 4: Indicates to the effect of source of drinking water on kidney stone Source of water Have kidney stone Have not kidney stone Percentage of patients having kidney stone Spring 3 12 20.00 Well 25 60 29.41 Calculated Chi-square=3.00 Tab. Chi-square=3.50 P≥0.15 Table 5: Indicates to the effect of eating meat on kidney stone Meat consumption Have kidney Have not kidney stone % of patients having kidney stone High 7 25 21.88 Medium 12 23 34.29 Low 9 24 27.27 Calculated Chi-square=1.29 Tab. Chi-square=3.40 P≥0.53 Table 6: Indicates to the effect amount of drunken water (L/day) on kidney stone-forming Amount of drunk water L/day Have kidney stone Have not kidney stone Percentage of patients having kidney stone Low (1–2) 16 33 32.65 Medium (2–3) 6 15 28.57 High (3–4) 6 24 20.00 Calculated Chi-square=1.47 Tab. value=3.20 P≥0.47 Esmail, et al.: Effect of drinking water hardness on kidney stones 4 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 Table 7: Effect of family history on kidney stone formation Family history Have kidney stone Have not kidney stone Percentage of patients having kidney stone Yes 11 23 32.35 No 17 49 25.76 Calculated Chi-square=0.48 Tab. value=3.50 P≥0.49 Table 8: Explains some important chemical properties of water samples in Raparin District Location Concentration (mg/L) SRI Hardness (mg/CaCO 3 /L) Mg2+ Ca2+ HCO 3 Mg2+ Ca2+ HCO 3 1-Spring 17.92 61.80 301.65 0.42 73.63 153.88 227.52 2-River 10.27 44.18 286.88 0.55 42.22 110.01 152.23 3-Spring 56.93 267.50 3057.93 0.06 233.97 666.08 900.05 4-Well 30.49 128.20 1653.10 0.09 125.32 319.22 444.54 5-Well 23.64 102.80 547.48 0.29 97.16 255.97 353.13 6-Well 23.02 91.86 474.46 0.31 94.60 228.73 323.33 7-Spring 19.93 59.78 318.54 0.34 81.92 148.85 230.77 8-Well 17.53 44.62 256.75 0.36 72.06 111.10 183.16 9-River 31.42 65.08 1164.49 0.07 129.12 162.05 291.17 10-Spring 11.94 50.48 238.39 0.65 49.07 125.70 174.77 11-Spring 17.11 88.30 454.08 0.42 70.33 219.87 290.20 12-Spring 20.81 88.52 402.05 0.39 85.52 220.41 305.94 13-Well 12.55 209.80 990.03 0.62 51.59 522.40 573.99 14-Well 15.72 146.00 735.66 0.46 64.61 363.54 428.15 15-Well 19.68 69.40 418.22 0.31 80.88 172.81 253.69 16-Well 11.81 63.16 273.65 0.72 48.53 157.27 205.80 17-Well 21.60 96.34 506.91 0.32 88.78 239.89 328.66 18-Well 24.24 83.22 408.64 0.31 99.63 207.22 306.84 19-Well 30.36 100.80 513.80 0.24 124.78 250.99 375.77 20-Spring 28.30 89.88 433.77 0.27 116.30 223.80 340.10 21-Spring 26.56 78.10 387.17 0.28 109.15 194.47 303.61 22-Spring 94.99 411.40 1808.65 0.09 390.42 1024.39 1414.80 23-Spring 26.74 65.44 349.90 0.26 109.88 162.95 272.83 24-Spring 28.30 78.90 409.86 0.25 116.30 196.46 312.76 25-Spring 26.44 69.08 356.67 0.27 108.65 172.01 280.66 26-Spring 26.71 70.06 371.55 0.26 109.79 174.45 284.24 27-Spring 12.22 40.26 193.68 0.62 50.21 100.25 150.46 28-Spring 63.29 234.80 1091.90 0.12 260.11 584.65 844.77 29-Spring 38.04 108.90 575.29 0.18 156.34 271.16 427.51 30-Well 12.88 55.38 257.73 0.61 52.92 137.90 190.82 31-Well 15.78 60.48 296.95 0.47 64.86 150.60 215.45 32-Well 14.42 55.46 271.51 0.52 59.28 138.10 197.38 33-Spring 29.57 95.16 459.33 0.26 121.52 236.95 358.47 34-Spring 31.03 113.70 527.47 0.25 127.54 283.11 410.65 35-River 41.88 99.14 551.32 0.16 172.13 246.86 418.99 36-Spring 20.29 64.86 315.92 0.37 83.40 161.50 244.90 37-Spring 13.08 43.92 220.33 0.56 53.76 109.36 163.12 (contd...) Esmail, et al.: Effect of drinking water hardness on kidney stones 5 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 Table 7 explains that the family history of the studied samples person had not affected significantly on kidney stone formation. Chi-square test refers to non-significant effect since the calculated Chi-square value (0.484) is less than tabulated value. Figure 1 shows the correlation between SRI and total hardness of 52 water resources (rivers wells and springs) in Raparin District. The coefficient of determination (R2) and correlation coefficient (r) between them was 0.426 and −0.65*, respectively. The SRI, coefficient of determination (R2), and correlation coefficient (r) were determined from the data recorded in Table 8. DISCUSSION Table 2 shows that the gender affected significantly on kidney stone formation the highest value (18%) was recorded from female, while (10%) was recorded from male this may be due to human activity of male more than female or may be due to biological difference male and female and lifestyle. Table 3 refers to highly significant effect of age on kidney stone (0.001). The kidney stone information increased from 19.25% to 75% for age class of (14–34) year to age class of more than (54) year, respectively, since every 10 years the kidney stone formation is possible as mention by Basiri et al.[1] and Kumar et al.[4] The statistical analysis using Chi-square test also indicated to significant effect of age on kidney stone formation since the calculated Chi-square value (15.50) was more than tabulated value which was equal to 3.50. On the other hand, the reverse results can be obtained depending on total sample size of this study because the sample size increased with decrease in age. Table 4 explains that non-significant effect of source of drinking water on kidney stone formation or there was no significant difference between water hardness of spring water and well water since both of them are hard water to very hard water.[9] The Mg-hardness represents 31% of total hardness as shown from Table 8, similar results were obtained by Basiri et al.[1] in the main cities of Iran which caused decrease in risk of stone formation. The significant negative correlation coefficient was recorded between the risk of stone formation and total hardness of 52 water samples in Raparin District with the value of r = −0.65** as shown from Figure 1 which decrease in the effect of total hardness of drinking water in kidney stone formation. These results agree with those recorded by Basiri et al.[1] Table 5 explains that consumed meat not affected significantly on kidney stone formation in spite of the Figure 1: Relation between total hardness of drinking water and stone risk index of kidney 38-Spring 18.40 69.06 328.12 0.42 75.61 171.96 247.57 39-Well 10.76 61.48 270.35 0.77 44.24 153.09 197.33 40-Spring 17.15 53.76 265.11 0.43 70.48 133.86 204.34 41-Well 18.06 77.78 355.94 0.44 74.23 193.67 267.90 42-Well 19.45 60.42 304.45 0.37 79.95 150.45 230.39 43-Well 23.62 80.14 388.39 0.32 97.06 199.55 296.61 44-Well 21.78 76.40 406.50 0.32 89.52 190.24 279.75 45-Well 27.19 91.88 451.03 0.27 111.76 228.78 340.54 46-Well 34.02 69.10 412.85 0.18 139.82 172.06 311.88 47-Spring 17.22 60.98 297.50 0.44 70.77 151.84 222.61 48-Well 24.38 84.04 416.33 0.30 100.22 209.26 309.48 49-Well 41.02 84.52 553.15 0.14 168.58 210.45 379.03 50-Well 25.16 101.50 476.59 0.31 103.42 252.74 356.16 51-Well 24.96 92.58 442.01 0.31 102.59 230.52 333.11 52-Spring 26.51 118.10 613.05 0.27 108.95 294.07 403.02 Min 10.27 40.26 193.68 0.06 42.22 100.25 150.46 Max 94.99 411.40 3057.93 0.77 390.42 1024.39 1414.80 Average 25.33 93.82 535.83 0.35 104.11 233.61 337.71 Location Concentration (mg/L) SRI Hardness (mg/CaCO 3 /L) Mg2+ Ca2+ HCO 3 Mg2+ Ca2+ HCO 3 Table 8: (Continued) Esmail, et al.: Effect of drinking water hardness on kidney stones 6 http://journals.cihanuniversity.edu.iq/index.php/cuesj CUESJ 2020, 4 (1): 1-6 difference in the percentage of kidney stone formation which ranged between (21.88% and 34.29%). Table 6 indicates to decrease in kidney stone formation from 32.65% to 20% with increase amount drunk water per day or water intake per day per person, this may be due to increase water may be prevent precipitation of crystals such as calcium, oxalate, and uric acid in the kidney then decrease stone formation. As shown from Table 7, the family history caused an increase in percentage of kidney stone formation from 25.76% to 32.35% but not reached to the significant effect. Its appear from the above discussion that there is more than one factor responsible for kidney stone formation for this reason, sometime the result for single factor is not significant, while the combination among the studied factors may cause the kidney stone formation. CONCLUSION AND RECOMMENDATIONS The kidney stone formation affected significantly by gender and amount of drunken water (L/day/person). The total water hardness was not affected significantly on kidney stone formation since magnesium hardness represents 31% of total hardness which caused decrease in the risk of kidney stone formation. The drinking water in Raparin District is hard to very hard, but they have not risk on kidney formation due to high magnesium and bicarbonate of the studied water resources. We highly recommend that: • It is necessary to increase sample size. • It is better to have the same number of studied samples for each age classes. • It is better to have the same number of male and female number in the suture studies. REFERENCES 1. A. Basiri, N. Shakhssalim, A. R. Khoshdel, H. Pakmanesh and M. H. Radfar. “Drinking water composition and incidence of urinary calculus”. Iranian Journal of Kidney Disease, vol. 5, no. 1, pp. 15-20, 2011. 2. A. O. Esmail. “Limitation of Some Ground Water Suitability in Erbil Plain for Different Uses”. M. Sc. Thesis, University of Salahaddin. In Arabic, 1986. 3. A. O. 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Dzegede. “Water hardness and urinary stone disease”. Journal of Urology, vol. 128, pp. 422-450, 1989. 19. D. J. Barker and S. P. Donnan. “Reginal variations in the indices of upper urinary tract stones in England and Wales”. The British Medical Journal, vol. 1, pp. 67-70, 1978. 20. B. M. Salam. “Limiting Water Suitablity in Ranya District for Different Uses.” MSc. Thesis Salahaddin Uinv. College of Agricultural Engineering Sciences, Department of Soil and Water, 2018.