Tag Archives: manganese

Should WHO restore the manganese guideline?

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.

 

 

Press Spin: Manganese makes non-news in Massachusetts

In 2004, USEPA issued a health advisory for manganese in drinking water (click here). This has been adopted and/or made available by states, including Massachusetts (click here). The fact that this advisory was issued is non-news today.

Seems like Lakeville, Massachusetts Board of Health has been snoozing and is now just waking up to this by issuing a manganese warning this month (click here)…..only took them 7+ years…

Yup, that board is focused like a laser, just like our President……..click here for news article….

Khan et al 2011: Manganese exposure from drinking water and children’s academic achievement

A typical ecologic study with all of the traditional limitations.  The abstract does not provide an adequate characterization of significance…..the lower 95% confidence limit of score loss is near zero….

Khan, K., G.A. Wasserman, X. Liu, E. Ahmed, F. Parvez, V. Slavkovich, D. Levy, J. Mey, A. van Geen, J.H. Graziano, and P. Factor-Litvak. 2011. Manganese exposure from drinking water and children’s academic achievement. Neurotoxicology. Dec 13.

Abstract: Drinking water manganese (WMn) is a potential threat to children’s health due to its associations with a wide range of outcomes including cognitive, behavioral and neuropsychological effects. Although adverse effects of Mn on cognitive function of the children indicate possible impact on their academic achievement little evidence on this issue is available. Moreover, little is known regarding potential interactions between exposure to Mn and other metals, especially water arsenic (WAs). In Araihazar, a rural area of Bangladesh, we conducted a cross-sectional study of 840 children to investigate associations between WMn and WAs and academic achievement in mathematics and languages among elementary school-children, aged 8-11 years. Data on As and Mn exposure were collected from the participants at the baseline of an ongoing longitudinal study of school-based educational intervention. Annual scores of the study children in languages (Bangla and English) and mathematics were obtained from the academic achievement records of the elementary schools. WMn above the WHO standard of 400μg/L was associated with 6.4% score loss (95% CI=0.5, 12.3) in mathematics achievement test scores, adjusted for WAs and other sociodemographic variables. We did not find any statistically significant associations between WMn and academic achievement in either language. Neither WAs nor urinary As was significantly related to any of the three academic achievement scores. Our finding suggests that a large number of children in rural Bangladesh may experience deficits in mathematics due to high concentrations of Mn exposure in drinking water.

Click here for the full study (fee).

Iron and manganese problem persists in Denmark, South Carolina

Discolored water and other issues result in unsatisfactory rating….click here.

Source: The Times and Democrat

T&D CORRESPONDENT JERRY DURGAN

Resident Johnnie Rosa at Monday’s Denmark City Council meeting holds up a bottle of discolored water she said she drew from her tap at home on Nov. 10. “You can’t wash clothes with it, let alone drink it,” she said.

Bryant et al 2011: Solving the problem at the source: Controlling Mn release at the sediment-water interface via hypolimnetic oxygenation

L.D. Bryant, H. Hsu-Kim. P.A., Gantzer, and J.C. Little. Solving the problem at the source: Controlling Mn release at the sediment-water interface via hypolimnetic oxygenation. Water Research. 2011 Dec 1;45(19):6381-92.
 
Absract: One of the primary goals of hypolimnetic oxygenation systems (HOx) from a drinking water perspective is to suppress sediment-water fluxes of reduced chemical species (e.g., manganese and iron) by replenishing dissolved oxygen (O(2)) in the hypolimnion. Manganese (Mn) in particular is becoming a serious problem for water treatment on a global scale. While it has been established that HOx can increase sediment O(2) uptake rates and subsequently enhance the sediment oxic zone via elevated near-sediment O(2) and mixing, the influence of HOx on sediment-water fluxes of chemical species with more complicated redox kinetics like Mn has not been comprehensively evaluated. This study was based on Mn and O(2) data collected primarily in-situ to characterize both the sediment and water column in a drinking-water-supply reservoir equipped with an HOx. While diffusive Mn flux out of the sediment was enhanced by HOx operation due to an increased concentration driving force across the sediment-water interface, oxygenation maintained elevated near-sediment and porewater O(2) levels that facilitated biogeochemical cycling and subsequent retention of released Mn within the benthic region. Results show that soluble Mn levels in the lower hypolimnion increased substantially when the HOx was turned off for as little as ∼48 h and the upper sediment became anoxic. Turning off the HOx for longer periods (i.e., several weeks) significantly impaired water quality due to sediment Mn release. Continual oxygenation maintained an oxic benthic region sufficient to prevent Mn release to the overlying source water.
 
 

Would you drink rusty tap water?

In one respect, customers get what they pay for…..so if water pipes need replacing, customers can put up the funds (in the form of higher water rates) to replace them. Of course, there may be other circumstances that make it not so easy.  Click here for more on this situation in Ohio.

Source: daytondailynews.com