Neural tube malformations and trace elements in water.

A retrospective case-control study was conducted to test the hypothesis that there is an association between the trace element content of domestic tap water and neural tube malformations in infants. Of 11 elements examined a notable difference was found only for zinc, this being lower in the cases than in the controls. This difference, however, was small and when allowance is made for the total number of statistical comparisons it is compatible with chance fluctuation. From the results of this study, together with the inconsistency of the literature as a whole, it is concluded that trace elements in tap water are unlikely to be of relevance to congenital malformations.