Zamzam water research
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| Zamzam |
Millions of pilgrims drink it and bring it as a gift for their relatives and friends when they return home. Zamzam water, supplied by the well of Zamzam (Figure 1), is available through taps and containers that are distributed in the Masjid Al Haram in Mecca.
Zamzam water is also available in a bottled form to facilitate air transportation for pilgrims who want to, as the Saudi government has banned the commercial export of Zamzam water.
The Zamzam well is about 30.5 m deep with a diameter ranging from 1.08 to 2.66 m. The well is now located on the ground floor surrounded by glass plates permitting a clear vision of the inside. The water is withdrawn by electrical pumps to become available in the taps distributed in specific areas in the mosque.
In 1976, the American Water Resource Association published the first international article about the chemical composition of Zamzam Water.
Other studies were also conducted on this topic, and the results were conflicting, especially regarding arsenic. Shomar found elevated levels of As, NO3-, Ca, and K in Zamzam water samples collected by pilgrims after their return from Mecca.
In 2011, BBC news interestingly announced the illegal sale of Zamzam drinking water contaminated with arsenic in UK shops. Conversely, the Saudi geographical survey states that it has a dedicated center (Zamzam Studies and Research Centre) that analyses and monitors the properties of Zamzam well. (Zamzam water)
Alfadul and Khan confirmed that As concentration was within the acceptable range endorsed by different committees. Al-Barakah et al recorded accepted levels of As and NO3- in Zamzam water samples regarding local and international standards.
Nevertheless, scientific studies on Zamzam water are scarce. Therefore, we conducted this study to explore the chemical composition of Zamzam water. chemical constituent.
We analyzed Zamzam water samples for their chemical composition (pH, TDS, Na, K, Mg, Ca, Fe, Cu, Zn, Cd, Pb, Mn, Al, As, Cl−, SO4−2, HCO3- and PO4−3) by the American Public Health Association (APHA) standard methods and compared these levels with the maximum allowable levels (MAL) defined by World Health Organization (WHO) and Environmental Protection Agency (EPA). This study might add more evidence about the safety of Zamzam water which is consumed by millions of Muslims around the world.
Materials and methods
Study design
Six Zamzam water samples from taps of Zamzam well in addition to a bottled Zamzam water sample were analyzed for their chemical composition (pH, TDS, Na, K, Mg, Ca, Fe, Cu, Zn, Cd, Pb, Mn, Al, As, Cl−, SO4−2, HCO3- and PO4−3). The results were compared to the international standards (WHO and EPA) for drinking water.
Reagents
Ultrapure deionized water (Millipore S.A., France) was used for the preparation of reagents and dilution throughout the work. The chemicals used were purchased from Merck (Darmstadt, Germany) and Sigma-Aldrich (St. Louis, MO, USA). Before use, glassware was soaked in 5% HNO3. It was then washed with tap water followed by deionized water.
Analysis
All samples were analyzed at the central laboratories of the Egyptian Mineral Resources Authority (EMRA); a subsidiary of the Egyptian ministry of petroleum and mineral resources. The choice of conducting analysis at these Governmental laboratories was based on their nationally-accredited standards, especially in the field of water analysis (equipment-staff). The staff of the analyzing laboratories was blind to the nature of water samples. Therefore, the analyzing laboratories don't bear any legal or ethical consequences due to the analysis of water samples in this study.
All measurements were performed according to APHA protocols. The pH was measured by using Metrohm 632 digital pH meter (Metrohm Autolab, Herisau, Switzerland). Total dissolved solids (TDS) were determined by the gravimetric method (APHA 2540 C). Major cations (Na, K, Mg, and Ca) and trace elements (Fe, Cu, Zn, Cd, Pb, Mn, Al, and As) were determined according to the standard method (APHA 3120) by Inductively Coupled Plasma-Optical Emission Spectrometry (Agilent technologies 720 ICP-OES Series, Santa Clara, CA, USA). Table S1 summarizes the ICP-OES operating parameters along with the instrumental limit of detections (LODs) for the metal ions. ICS-2000 ion chromatograph (Thermo Scientific, Waltham, MA, USA) equipped with Dionex Ion Pac AS 14 column was used for determination of Cl− and SO42. HCO3- was determined by titration procedure according to APHA standard method 2320. The ascorbic acid method (APHA 4500 P-E) was used for the determination of PO43-. Analysis of standard solutions and samples was performed in triplicate. Data were expressed as Mean ± standard deviation (SD). ANOVA test was performed to statistically compare data. p-value <0.05 was considered significant.
Quality control program
The precision of analysis was assessed by calculation of relative standard deviations (RSD). The within-run and between-run RSD didn't exceed 5.0% for all analyses. Recovery of the analyte from spiked samples was used to evaluate the accuracy of the procedure. The recoveries of analytes were in the range of 96.0–102.0%.
Results
The concentrations of all analytes along with drinking water standards of WHO and EPA are presented in the table. All parameters were within the accepted limits of the international institutions except for TDS which only affects the taste of water and has no significant health impacts. The mean values of T.D.S. were 814 and 812 mg L−1 in the collected and bottled samples, respectively. These levels exceed the MAL defined by EPA (500 mg L−1) and are lower than that assigned by the WHO (1000 mg L−1). On the other hand, As and Cd concentrations in all samples were below the LOD of ICP-OES (3.3 and 0.2 μg L−1 for As and Cd, respectively) which are lower than the WHO and EPA standards. This indicates that the concentrations of As and Cd in all analyzed samples are also below the MALs of WHO and EPA.
| Parameter | Unit | Directly-collected Zamzam water | Bottled Zamzam water | Maximum allowable limits | |
|---|---|---|---|---|---|
| WHO | EPA | ||||
| pH | - | 7.65 ± 0.1 | 7.6 ± 0.1 | 6.5–9.5 | 6.5–8.5 |
| T.D.S. | mg L−1 | 814.0 ± 13.2 | 812 ± 14 | 1000 | 500 |
| Na | mg L−1 | 119.6 ± 17.3 | 72.5 ± 6.8∗∗ | - | - |
| K | mg L−1 | 37.5 ± 4.0 | 30.8 ± 3.3 | - | - |
| Mg | mg L−1 | 20.5 ± 1.7 | 18.5 ± 1.4 | - | - |
| Ca | mg L−1 | 71.5 ± 6.0 | 74.0 ± 7.3 | - | - |
| Fe | μg L−1 | 80.8 ± 5.9 | 86.5 ± 6.3 | 300 | 300 |
| Cu | μg L−1 | 1.8 ± 0.4 | 1.1 ± 0.3∗ | 1000 | 1300 |
| Zn | μg L−1 | 13.7 ± 2.9 | 10.5 ± 2.1 | 5000 | 5000 |
| Cd | μg L−1 | BDL | BDL | 3 | 5 |
| Pb | μg L−1 | 0.65 ± 0.11 | 0.54 ± 0.08 | 50 | 15 |
| Mn | μg L−1 | 1.70 ± 0.22 | 1.71 ± 0.24 | 100 | 50 |
| Al | μg L−1 | 28.4 ± 3.3 | 20.1 ± 2.8 | 200 | 200 |
| As | μg L−1 | BDL | BDL | 10 | 10 |
| Cl- | mg L−1 | 158.7 ± 7.1 | 149.5 ± 6.5 | 250 | 250 |
| SO4−2 | mg L−1 | 110.8 ± 15.8 | 96.5 ± 13.0 | - | 250 |
| HCO3- | mg L−1 | 177.2 ± 10.8 | 184.0 ± 11.6 | - | - |
| PO4−3 | mg L−1 | 0.11 ± 0.02 | 0.06 ± 0.01∗ | - | - |
∗p < 0.05.
∗∗p < 0.01.
*WHO guidelines for drinking-water quality (4th edition, World Health Organization, 2011, Geneva).
*U.S. Environmental Protection Agency (US EPA) National Primary drinking Water Regulations 2011
Both collected and bottled Zamzam water samples were compared relative to their chemical analysis. No significant differences were observed (p˃0.05) except for Na+, Cu2+, and PO4−3. The bottled Zamzam water sample had significantly lower levels of Na+, PO4−3 (p˂0.05), and Cu2+ (p˂0.01) compared to the collected samples.
Discussion
The study was designed to resolve conflicts about the safety of Zamzam water and give reassurance to millions of Muslims who drink little of it in honor and blessings. The results of the present study pointed out that the chemical composition of Zamzam water is acceptable according to the guidelines of WHO and EPA for drinking water, except for TDS.
Our study showed that arsenic concentrations were below the instrumental detection limit in all Zamzam water samples (bottled and tap-collected samples). Arsenic concentration in Zamzam water had conflicting results in the literature. In his well-designed study, Shomar [8] reported high arsenic levels (average concentration = 27 μg L−1) in Zamzam water samples that were either brought to or sold in Germany. On the other hand, Al-Barakah et al [10] reported arsenic levels that are within permissible limits [0.006–7.728] in Zamzam water collected and analyzed in Saudi Arabia. Differences among studies could be explained by many factors including differences in the laboratory methods used for water analysis as well as in the material used due to variable water samples and ways of collection. In addition, it is possible that arsenic concentration in Zamzam water is dynamically and being affected by civil activities in the vicinity of the well. Except for long-term inhabitants and citizens of the country of Saudi Arabia, Zamzam water consumption is expected to be a temporary behavior being limited by the relatively short period of pilgrimage (days-weeks), the relative unavailability of Zamzam water outside ritual areas, the relatively small volume of water that is allowable for pilgrims on returning to their countries (only one authorized 5-liter package of bottled Zamzam water is freely permissible for every returnee) and the possible division of carried water on relatives and friends. As per the WHO report on chemical aspects of drinking water, most chemicals arising in drinking water are of health concern only after extended exposure of years, rather than months. Nevertheless, the arsenic content of Zamzam water has gained increased attention, perhaps because the WHO declares inorganic arsenic as a confirmed carcinogen and the most significant chemical contaminant in drinking water globally. Intake of inorganic arsenic over a long period can lead to chronic arsenic poisoning (arsenicosis). Effects, which can take years to develop depending on the level and route of exposure, include skin lesions, peripheral neuropathy, gastrointestinal symptoms, diabetes, cardiovascular disease, developmental toxicity, and cancer of the skin and internal organs. Therefore, official, periodically-updated reports on Zamzam water analysis issued by the local authority are needed (including water from the well and at different distribution points).
Similar to arsenic, Cd was below the detection limit in all Zamzam water samples included in our study. In addition, the concentrations of all other tested threshold analytes (chemicals that have maximum allowable limits) were well below the maximum allowable limits stated by WHO and EPA.
The mean values of TDS in the directly collected, as well as the bottled Zamzam water samples, were 814 and 812 mg L−1, respectively. TDS comprises inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and small amounts of organic matter that are dissolved in water. Generally, TDS in drinking water originates from natural sources, sewage, urban runoff, and industrial wastewater. Concentrations of TDS in water vary considerably according to geological regions owing to differences in the solubility of minerals. WHO doesn't suggest a guideline value for TDS as it is not of health concern at levels found in drinking water. Nevertheless, drinking water becomes significantly and increasingly unpalatable at TDS levels greater than about 1000 mg L−1
The bottled Zamzam water sample had significantly lower levels of Na+, PO4−3, and Cu2+ compared to the collected samples. The treatment of bottled water could be responsible for such differences. Al-Any et al, reported that bottled Zamzam is ozonated. Nevertheless, this method, up to our knowledge, has not been reported by either the official websites or other authors. The detailed method of bottling needs to be clarified.
Conclusion
Our study shows that Zamzam water has an acceptable chemical profile. Nevertheless, larger blind studies are needed. Apart from bias that would affect studying such a religious and spiritual subject, other factors may also affect the results of Zamzam water studies. These include a multiplicity of destinations of Zamzam water, different assay methods, and enormous civilizational activities around the well. Therefore, the periodic announcements of Zamzam water analysis results by the local authority are expected to be the most accurate way to explore the nature of Zamzam water. Efforts are made by the local authorities to maintain Zamzam well. To our knowledge, no official analysis results were periodically published. Nevertheless, official reports would reassure consumers of Zamzam water.
References
- G. Shahzad, R. Rehan, M. Fahim
T.S. Hussain, A.H. Al-Fatlawi
Remove chemical contaminants from potable water by household water treatment system.
Saudi geological survey
The ministry of hajj and umrah (pilgrimage)
Holy Bible NIV
NIV® Copyright ©1973
N. Khalid, A. Ahmad, S. Khalid, A. Ahmed, M. Irfan
Mineral composition and health functionality of Zamzam water: a review
S.A. Al-Ansi, A.A. Othman, M.A. Al-Tufail
Bromate pollutant in ozonated bottled Zamzam water from Saudi Arabia determined by LC/ICP-MS
B. Shomar
Zamzam water: concentration of trace elements and other characteristics
S.M. Alfadul, M.A. Khan
Water quality of bottled water in the kingdom of Saudi Arabia: a comparative study with Riyadh municipal and Zamzam water
F.N. Al-Barakah, A.M. Al-jassas, A.A. Aly
Water quality assessment and hydrochemical characterization of Zamzam groundwater, Saudi Arabia
G. Lynn
Contaminated 'zam zam' holy water from Mecca sold in the UK. BBC News
E.W. Rice, R.B. Baird, A.D. Eaton, L.S. Clesceri
Standard Methods for the Examination of Water and Wastewater
WHO
Guidelines for Drinking Water Quality
(fourth ed.), World health organization, Geneva (2011)
Warning about drinking 'Zamzam' water
K. Jomova, Z. Jenisova, M. Feszterova, S. Baros, J. Liska, D. Hudecova, et al.
Arsenic: toxicity, oxidative stress, and human disease
A.P. Singh, R.K. Goel, T. Kaur
Mechanisms of arsenic toxicity
General presidency for the affairs of the grand mosque and the prophet’s mosque
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