Observational study tracks anencephalus incidence across differing water hardness levels in newborn populations, suggesting environmental minerals may influence neural-tube closure.
Key Points
To determine whether geographical and temporal differences in drinking water hardness correlate with regional rates of anencephalus.
Systematic epidemiological surveillance of congenital malformations in Liverpool and south-west Lancashire from July 1963 to June 1968.
Comparison of birth defect frequencies across soft-water regions, a stable hard-water district (Southport), and a locality that switched from hard to softened water during the study period (St. Helens).
Cross-verification of all identified anencephalic birth records with local maternity department registers.
National epidemiological data across England and Wales demonstrate a significant negative correlation between municipal water hardness and anencephalus rates.
Local monitoring in Lancashire established baseline rates across soft and hard water zones to evaluate if artificial water softening changes the frequency of neural-tube closure defects.