Excessive urinary excretion of calcium is the major risk of urinary
stone formation (Curhan, 2007; Curhan et al., 2001; Worcester
and Coe, 2008). Our previous study among adults living in
cadmium-contaminated areas revealed a positive association between
urinary cadmium levels and prevalence of urinary stones
(Swaddiwudhipong et al., 2011). Although urinary stone diseases
were not found in our children studied, an increase in calciuria
induced by cadmium might increase the risk of urinary stone
formation in those with prolonged exposure to cadmium.