Contribution of Drinking Water Softeners to Daily Phosphate Intake in Slovenia

Phosphate drinking water softeners promote Legionella growth

Phosphate-based drinking water softeners are commonly used to prevent scale formation in drinking water distribution infrastructure. The main reason for drinking water softening is primarily economic (protection of pipes and extension of equipment life), while the health aspect of such treatment is usually neglected. The aim of this work is to investigate the effects of phosphate-based drinking water softeners on growth stimulation of Legionella pneumophila. Bacterial growth was observed at two different phosphate concentrations. On average, an increase in growth of 1.19-1.28 log CFU/mL was observed in selected samples with added phosphates compared with the control. The results of the in vitro experiment confirmed that the added phosphates stimulate the growth of L. pneumophila; growth stimulation could therefore be expected in drinking water distribution systems (DWDS) when phosphates are used as well. The availability of phosphorus in DWDS may be a crucial limiting factor for biofouling control. Consequently, phosphate-based chemicals for drinking water should be avoided or used with prudence, especially in drinking water with high concentrations of other nutrients.

Dietary Phosphate and the Forgotten Kidney Patient: A Critical Need for FDA Regulatory Action

Careful dietary management that reduces high phosphate intake is recommended to slow the progression of chronic kidney disease (CKD) and prevent complications of CKD and may help reduce chronic disease risks such as incident CKD associated with high phosphate intake in the healthy general population. For patients treated with maintenance dialysis, control of serum phosphorus levels is considered a marker of good care and requires a coordinated plan that limits dietary phosphate intake, uses oral phosphate binders, and provides an adequate dialysis prescription. Even with traditional thrice-weekly hemodialysis or peritoneal dialysis, use of phosphate binders, and a concerted effort to limit dietary phosphate intake, adequately controlled serum phosphorus levels are not possible in all dialysis patients. Efforts to limit phosphate intake are thwarted by the underestimated and unquantified phosphate content of processed foods and some medications due to the hidden presence of phosphate additives or excipients added during processing or drug formulation. Effectively limiting phosphate intake could potentially be achieved through simple US Food and Drug Administration regulatory actions. Mandatory labeling of phosphate content on all packaged foods and drugs would enable identification of healthy low-phosphate foods and medications and permit critically important control of total phosphate intake. Simple changes in regulatory policy and labeling are warranted and would enable better management of dietary intake of phosphate at all stages of kidney disease, as well as potentially reduced health risks in the general population.