Serious poisoning, which was caused by the materials that can be found in small amount in city tap water such as bacteria endotoxins, chlorine compounds, excessive calcium, magnesium, fluoride and aluminum, was observed due to the fact that the importance of the purification of water used in the hemodialysis water in the first years of hemodialysis. Although the presence of those materials in water might not cause an observable problem in people which drink and use those waters, it can be understood why it causes serious poisoning in the hemodialysis patients; Since end stage renal patients’ kidneys cannot perform the removal of toxins from the body function and this results in the accumulation of toxic materials easily. On the other hand, while a person drinks 10-15 liters of water in a week, a hemodialysis patient get in touch with 300-800 ml dialysis solution per minute during the hemodialysis and totally 300-400 liter dialysis solution and its all ingredients including the toxic materials in a week. This contact becomes directly through blood and they cannot use any defense mechanism such as bad taste sensing, nausea, and vomiting that sensory organs perform against the toxins in question. Thus, dialysis water must be much purer and more purified from dangerous materials.

-In our laboratory, analyses of all parameters for the hemodialysis water indicated in Appendix-1 Table-1 and Table-2-
The major toxic materials which can be found in city tap water and the problems they cause are summarized below;
Aluminum: Aluminum hydroxide is used as precipitator for the foreign materials in the purification of the city water. Besides excess aluminum might cause dialysis encephalopathy, which is brain and neuron destruction, it can also exacerbate the commonly seen bone problems in uremic patients by accumulating in the bones.
Calcium and Magnesium: They cause a clinical picture called “Hard water syndrome” progressing with nausea, vomiting, muscle weakness, redness in skin, hypertension or hypotension.
Chlorine Compounds: Chlorine and Chlorine compounds are used as bactericides in the water purification facilities. They cause blood problems such as hemolytic anemia and methemoglobinemia.
Copper: It is due to the copper pipes used in the water systems in the past. It causes nausea, shivering, liver destruction, fatal hemolysis.
Fluoride: It can cause osteomalacia, osteoporosis, and other bone problems.
Nitrate: It might causer cyanosis, methemoglobinemia, hypotension, and nausea.
Zinc: It can mix to the water from the galvanized or zinc pipes. It can cause nausea, vomiting and anemia.
Bacterial endotoxins: Even though the bacteria are dead, endotoxins of the bacteria reproduced in water systems might cause shivering, fever, nausea, hypotension and cyanosis.

Taking the Water Samples
If there is no instruction according to the laboratory quality management system, the Water Sample Taking is done according to “Water Sample Taking Rule”. During sample taking of water or delivery to cargo, presence of an official from health authority, signing the protocol to be prepared and labeling the tags prepared by the authority, declaration of the process as null and void of the analysis from the samples without label is necessary for the control of the process.

Control of Water Purification System
1- In the chemical and bacteriological control of water used in during the dilution of hemodialysis solutions, the limitations indicated in European Union Pharmacopeia in Appendix-1 should be considered.
2- The chemical and endotoxin control of the RO water system exit water should be done in once in 6 months, and in the private laboratories or public laboratories, having the license according to the related legislation, and making the analyses with the method and equipments indicated in “Water Monograph Used in Dilution of Hemodialysis Solutions” suggested in Legislation appendix Appendix-1 Table-2.
3- Bacteriological controls should be done in once in 3 months, in public laboratories or private licensed laboratories present in the same city. However, if it cannot be done in the same city, it can be done in another city only if the cold chain conditions are met. To be able to make bacteriological control, water sampling valves should be placed in key points of the system. Chemical analysis and endotoxin analysis might be done in different city.
4- All the rings of the chain making the system from water purification system to dialysis machine should be controlled every day by the help of simple indicators (hardness, conductivity, pressure decrease, pH, chlorine).
APPENDIX-1 Maximum contamination levels of the water used in the dilution of concentrated hemodialysis solutions defined in 1167 numbered monograph in Europe Pharmacopeia: 
Table 1. Maximum bacteriological levels according to Europe Pharmacopeia                                          

  Pure Water Ultra-Pure Dialysis Liquid
Microbial contamination (CFU/ml) <100 <0.1
Bacterial endotoxin (IU/ml) <0.25 <0.03

Pure Water (RO Water): The purified water used in the dilution of the concentrated hemodialysis liquids during the standard hemodialysis.
Ultra-pure Dialysis Liquid: Dialysate or replacement water used in hemofiltration or hemodiafiltration.

 

Table 2. Maximum contamination levels of pure water according to Europe Pharmacopeia

Parameter Method Maximum Level
Acidity – Alkalinity Chemical Test Compliance
Oxidizable Materials Chemical Test Compliance
Total present chlorine Chemical 0.1 ppm
Chlorine Chemical 50 ppm
Fluoride Potentiometric 0.2 ppm
Nitrate Chemical 2 ppm
Sulfate Chemical 50 ppm
Aluminum Fluorescent Spectrophotometry – Atomic absorption 10 µg/L
Ammonium Chemical 0.2 ppm
Calcium Atomic absorption spectrometry 2 ppm
Magnesium Atomic absorption spectrometry 2 ppm
Mercury Atomic absorption spectrometry – ICP-MS 0.001 ppm
Potassium Flame Photometry 2 ppm
Sodium Flame Photometry 50 ppm
Zinc Atomic absorption spectrometry 0.1 ppm
Heavy Metals (lead) Atomic absorption spectrometry – Chemical 0.1 ppm
Microbial Contamination Pour plate 100 CFU/ml
Bacterial Endotoxin LAL 0.25 IU/ml (For the ultra-pure dialysis water 0.03)

REFERENCES
1- 28.10.2011 dated and 44047numbered “Water Purification System Regulation”.
2-F. Fevzi ERSOY, “Tools and Equipments used in Hemodialysis”.
3-Handbook of Dialysis. Daugirdas JT, Ing TS (eds). Little, Brown and Company, Boston 1994.
4-Replacement of renal function by dialysis. Jacobs C, Kjellstrand CM, Koch KM, Winchester JF (eds). Kluwer Academic Publishers, Dordrecht 1996.
5-Akoğlu E. Hemodialysis Handbook. 1995.