Water hardness and urinary stone disease

Area of Science:

• Urology
• Environmental Health
• Epidemiology

Background:

• A macrogeographic association between lower water hardness and higher urinary stone disease incidence exists in the US.
• Microgeographic studies are needed to control for environmental factors influencing this association.

Purpose of the Study:

• To investigate the association between water hardness and urinary stone disease on a microgeographic scale.
• To control for confounding environmental factors in the analysis.

Main Methods:

• A comparative study of 2,295 patients from the Carolinas (soft water, high stone incidence) and the Rockies (hard water, low stone incidence).
• Analysis of home tap water samples from urinary stone patients and controls (inguinal hernia patients).
• Adjustment for environmental factors.

Main Results:

• No significant difference in tap water calcium, magnesium, and sodium concentrations between stone formers and controls after adjusting for environmental factors (p = 0.59).
• Individuals consuming water from private wells showed an increased relative risk (1.5, p < 0.01) for urinary stones compared to those using public water.

Conclusions:

• Water hardness appears to be a minor concern for urinary stone formation.
• Private well water consumption may be a risk factor for urinary stones, meriting further research.
• Further investigation into the link between private well water and urinary stone disease is recommended.