These authors argue that the World Health Organization (WHO) should restore and lower the guideline for manganese…..well perhaps. It seems that WHO guidelines may not be the authoritative source on drinking water quality……the abstract is below. Click here for a prepublication copy of the paper.
Frisbie SH, Mitchell EJ, Dustin H, Maynard DM, Sarkar B 2012. World Health Organization Discontinues Drinking Water Guideline for Manganese. Environ Health Perspect. http://dx.doi.org/10.1289/ehp.1104693
Background: The World Health Organization (WHO) released the 4th edition of Guidelines for Drinking-water Quality in July, 2011. In this edition, the 400 µg/L drinking water guideline for manganese (Mn) was discontinued with the assertion that since “this health-based value is well above concentrations of manganese normally found in drinking-water, it is not considered necessary to derive a formal guideline value.”
Objectives: This paper reviews the WHO drinking water guideline for Mn, from its introduction in 1958 through its discontinuation in 2011.
Methods: We used WHO publications documenting the guidelines as primary references. We identified countries with drinking water or potential drinking water supplies exceeding 400 µg/L of Mn from peer reviewed journal articles, government reports, published conference proceedings, and theses. We summarized the health effects of Mn from peer reviewed journal articles.
Discussion: Drinking water or potential drinking water supplies with Mn concentrations above 400 µg/L are found in a substantial number of countries worldwide. The drinking water of many tens of millions of people has Mn concentrations above 400 µg/L. Recent research on health effects of Mn suggests that the earlier 400 µg/L WHO guideline may have been too high to adequately protect public health.
Conclusions: The toxic effects and geographic distribution of Mn in drinking water supplies justify a re-evaluation by the WHO of its decision to discontinue its Mn drinking water guideline.