In dialysis, the recommended maximum levels of chemical contaminants are the same as those for the water used for dialysate preparation. Long-term exposures to such chemical metal are harmful to dialysis patients, as the chemical concentration must not exceed the limits set out in (ISO 23500, 2019 and ANSI/AAMI 23500, 2019) [7, 8].
In this regard, the results of the present study were in line with those of some previous studies and did not match some others.
In a previous study by Humudat in Baghdad, Iraq, the characteristics of the water quality of the hemodialysis treatment plants in four hospitals were investigated. The results of this research showed that the concentration of free chlorine in all of the samples of dialysis water was not higher than standard limits, which comply with those of the current study [2]. While the lack of free chlorine in the treatment plants for dialysis water meant that there was initially an inadequate amount of chlorine applied to the water. The reasons for the different levels of municipal water may have been the disinfection methods of municipal water treatment plants and the climatic conditions during the study period [9].
In the current study, the concentration of aluminum was lower than standard limits in all the samples. The results of the study regarding the concentration of aluminum were not similar to the other study by researchers in Iraq. Their study on 18 compositions in the dialysis water showed that the concentrations of metal such as aluminum were higher than the standard limit [9, 10].
Researchers investigated the trace chemical quality of dialysis water and compared it with international standards for the hemodialysis treatment plants in other hospitals [11]. Results showed that the value of the measured parameters was significantly higher than the standard values due to the dialysis feed water can be a significant source of toxic trace elements that may accumulate due to high exposure, especially during hemodialysis. These results were not compatible with those of the current study.
In the study by Sandgol et al. [12] in Khatam-al-Anbia Hospital, the aluminum level in the dialysis water was higher than the standard while in this study, although all of the elements considered were significantly lower than the standard in this study.
Arvanitidou et al. [13] reported that the amount of nickel, iron, and aluminum in dialysis water was higher than the normal in 85 health centers in Greece. In addition, the analysis performed by Sobrino et al. on 30 elements in Mexico [14] showed that only aluminum was higher than the AAMI norm among the elements considered, while this problem was the opposite in the current study. However, the study by Pirsaheb et al. indicated that lead and chromium concentrations were increased in the water of the dialysis, which may be due to the higher concentration of the considered elements in the feed water of dialysis [15].
Reverse osmosis is capable of excluding metal ions, aqueous salts, and molecules from the water being treated [16]. In some hemodialysis treatments in the state of São Paulo, Brazil use pre-treatment components along with the reverse osmosis process to generate filtered water. Pretreatment is responsible for removing sediments, organic materials, minerals, and chlorine/ chloramine from incoming water [1].