XPost: pl.soc.polityka, pl.sci.medycyna, pl.pregierz   
   XPost: alt.pl.zbluzgaj, pl.biznes   
   From: user5066@newsgrouper.org.invalid   
      
   International Court of Internet Justice    
   posted:   
      
   >   
   > Testy twardości wody:   
   > woda w kranie u kolegi 300ppm,   
   > u mnie 110ppm,   
   > woda przegotowana w czajniku, zimna, odstawiona: 250ppm   
   > woda mineralna z plastikowej butelki 850ppm   
   >   
   > Zapraszam do zapoznania się moją pracą naukową nt. twardości wody,   
   > norm twardości wody i wpływu spożywania twardej wody na występowanie   
   kamicy nerkowej,   
   > kamicy pęcherza moczowego, raka prostaty, raka krtani, egzem skóry.   
   >   
   >   
   > Na życzenie dołączona zostanie wersja w języku polskim.   
   >   
   >   
   > ====================================================================   
   >   
   >   
   > Hardness of Drinking Water: Health Impacts and Global Standards   
   > Abstract   
   >   
   > This analytical review examines current drinking water hardness guidelines   
   from WHO and major jurisdictions (Europe, North America, Australia), and   
   studies the long-term health effects of consuming hard tap water. Particular   
   attention is paid to risks    
   associated with kidney stones, urinary tract diseases, skin conditions, and   
   potential links to cancer.   
   > 1. Definition and Classification of Water Hardness   
   >   
   >     Water hardness is defined as the sum concentration of calcium (Ca²⁺)   
   and magnesium (Mg²⁺), expressed in mg/L CaCO₃ or mmol/L.   
   >   
   >     Hardness categories:   
   >   
   >         Soft: <60 mg/L CaCO₃   
   >   
   >         Moderate: 60–120 mg/L   
   >   
   >         Hard: 120–200 mg/L   
   >   
   >         Very hard: >200 mg/L   
   >         Genius Canada+3guidelines.nhmrc.gov.au+3Wikipedia+3   
   >   
   > 2. Global Norms for Drinking Water Hardness   
   > World Health Organization (WHO)   
   >   
   >     WHO does not set a specific upper limit for hardness, as Ca and Mg are   
   not harmful at typical levels.   
   >   
   >     A working group suggested desirable ranges: Ca 40–80 ppm, Mg   
   20–30 ppm; total hardness 2–4 mmol/L (~80–200 mg/L). However,   
   evidence was inadequate to codify mandatory limits.   
   >     Wikipedia   
   >   
   > European Union   
   >   
   >     No formal EU maximum for hardness; a minimum of ~60 mg/L CaCO₃ is   
   considered desirable for taste and corrosion control.   
   >     guidelines.nhmrc.gov.au   
   >   
   > Australia   
   >   
   >     The guideline recommends maximum 200 mg/L CaCO₃ to avoid scaling in   
   hot water systems. Beyond this causes significant nuisance.   
   >     health.com+15guidelines.nhmrc.gov.au+15Genius Canada+15   
   >   
   > Canada   
   >   
   >     Water supplies >200 mg/L are deemed “poor”, and >500 mg/L   
   unacceptable for domestic use. No strict health-based maximum.   
   >     guidelines.nhmrc.gov.au+2open.canada.ca+2open.canada.ca+2   
   >   
   > USA   
   >   
   >     The EPA does not regulate hardness; it is considered a secondary   
   contaminant (aesthetic impact only). No formal limits.   
   >     open.canada.ca   
   >   
   > South America / India   
   >   
   >     National norms vary; in India, BIS tolerates hardness up to 500 mg/L,   
   but ecological studies found regional groundwater often exceeding safe levels   
   (~330 mg/L CaCO₃ linked to kidney stone risk).   
   >     pmc.ncbi.nlm.nih.gov   
   >   
   > 3. Health Impacts of Long-Term Consumption of Hard Water   
   > 🔬 Kidney Stones (Nephrolithiasis)   
   >   
   >     UK Biobank cohort (n = 288,041):   
   >   
   >         No overall significant correlation between hardness and stone   
   formation.   
   >   
   >         Subgroup (women and individuals over 60): hard water increased risk   
   by 18–34%.   
   >   
   >         High magnesium (>5 mg/L) appeared protective in younger men (<45   
   years) without renal failure.   
   >         Genius Canada+6PubMed+6pmc.ncbi.nlm.nih.gov+6   
   >   
   >     Controlled crossover study: individuals drinking hard water (255 mg   
   Ca²⁺/L) had ~50% higher urinary calcium; Ca‑citrate index increased   
   threefold, suggesting higher recurrence risk.   
   >     PubMed   
   >   
   >     Another study: increased hardness correlated with higher urinary   
   Ca/citrate ratio in stone-formers; elevated risk.   
   >     PubMed   
   >   
   > 🧬 Cancer Risk (Prostate, Bladder, Pancreas, Larynx)   
   >   
   >     UK Biobank nested analysis (n = 447,996):   
   >   
   >         U‑shaped association with all‑cause cancer and prostate cancer:   
   moderate hardness linked to lower risk, very hard water associated with higher   
   risk compared to soft water.   
   >   
   >         No significant association with Mg for cancer protection. Complex   
   interplay with mineral exposure.   
   >         pmc.ncbi.nlm.nih.gov+1PubMed+1   
   >   
   >     Evidence on bladder, prostate, testicular, laryngeal, pancreatic cancer   
   is limited and inconsistent. No strong epidemiological link established.   
   >   
   > 🧴 Skin Conditions (Eczema, Dermatitis)   
   >   
   >     Meta-analysis: areas with high hardness water exhibit higher rates of   
   atopic dermatitis in children; no evidence softeners improve established AD.   
   >     avensonline.org+3Wikipedia+3Wikipedia+3   
   >   
   >     Reddit and case observations: irritation due to residue of soap   
   salts/minerals disrupting skin barrier.   
   >     health.com+1avensonline.org+1   
   >   
   > 🫀 Other Observed Effects   
   >   
   >     Some weak inverse correlation between moderate hardness and   
   cardiovascular disease/mortality in men (up to 170 mg CaCO₃/L). Data   
   inconclusive.   
   >     Wikipedia   
   >   
   > ❌ No documented links   
   >   
   >     No strong peer-reviewed evidence linking water hardness to bladder   
   stones, testicular cancer, laryngeal or pancreatic cancer, or systemic   
   inflammation. Most associations remain speculative.   
   >   
   > 4. Synthesis & Recommendations   
   >   
   >     Kidney stones: long-term exposure to hard water may modestly increase   
   risk in older women; high magnesium offers some protective benefit in   
   subgroups.   
   >   
   >     Cancer: moderate hardness may be protective; extremely high levels could   
   elevate certain cancer risk—more prospective research needed.   
   >   
   >     Dermatological issues: hard water may exacerbate eczema, especially in   
   infants; mitigation via skin-friendly practices recommended.   
   >   
   >     Cardiovascular & metabolic: possible slight benefit from mineral   
   content; evidence too weak for firm conclusions.   
   >   
   > 5. Policy & Public Health Implications   
   >   
   >     Despite no global mandatory limit, regional norms generally identify   
   >200 mg/L as problematic for domestic systems.   
   >   
   >     Certain regions (India, parts of Canada) regularly exceed these   
   aesthetics norms, raising public health concerns.   
   >   
   >     Given emerging health evidence, jurisdictions may consider recommending   
   soft water for sensitive populations (e.g. individuals with stone risk,   
   children with eczema).   
   >   
   > 6. Conclusion   
   >   
      
   [continued in next message]   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)