Tag Archives: manganese

Mn and Al deposits in drinking water distribution systems

Li G, Ding Y, Xu H, Jin J, Shi B. Characterization and release profile of (Mn, Al)-bearing deposits in drinking water distribution systems. Chemosphere. 2018 Jan 9;197:73-80. doi: 10.1016/j.chemosphere.2018.01.027.

Inorganic contaminants accumulation in drinking water distribution systems (DWDS) is a great threat to 2 without well crystalline form. The relative abundance of Mn and Fe in deposits changed with their distance from the water treatment plant. Compared with iron in corrosion scales, Mn and Al were more labile to be released back into bulk water during unidirectional flushing process. A main finding of this work is the co-release behavior of Mn and Al in particulate form and significant correlation exists between these two metals. Dual control of manganese and aluminum in treated water is proposed to be essential to cope with discoloration and trace metal contamination in DWDS.

No Clear Association Between Manganese Exposure and Cognitive Development in Sample of School-Age Children

Bouchard MF, Surette C, Cormier P, Foucher D. Low level exposure to manganese from drinking water and cognition in school-age children. Neurotoxicology. 2017 Jul 15. pii: S0161-813X(17)30154-7. doi: 10.1016/j.neuro.2017.07.024.

BACKGROUND: Manganese (Mn) is an element found in the environment and certain geographic areas have elevated concentrations in soil and water du to natural conditions or anthropic activities. A growing body of data suggests that exposure to manganese in drinking water could be neurotoxic.

OBJECTIVE: Firstly, we aimed to examine the association between exposure to manganese from drinking water and cognition in children consuming well water. Secondly, we also aimed to examine the relation between cognition and manganese concentrations in children’s hair, nail, and saliva.

METHODS: A total 259 children from 189 households consuming well water were included in the present study (ages 5.9 to 13.7 years). We assessed children’s cognition with the WISC-IV, and we used five indicators of manganese exposure: concentration in tap water, intake from the consumption of water divided by child’s weight, manganese concentration in children’s hair, toe nail, and saliva. We used General Estimating Equation analysis to assess the relation between manganese exposure indicators and IQ scores, adjusting for potential confounders, and taking into account family clusters.

RESULTS: Drinking water manganese concentrations were generally low, with 48% of children consuming water <5>g/L, 25% >50>g/L, and 4% >400>g/L. Results differed by sex. In girls, higher manganese concentration in water, hair, and toe nail were associated with poorer Performance IQ scores but this was significant only for toe nail (for a 10-fold increase in manganese, β: -5.65, 95% CIs: -10.97, -0.32). Opposite associations were observed in boys, i.e., better Performance IQ scores with higher manganese concentration hair, toe nail, and water, the latter being significant (β: 2.66, 95% CIs: 0.44, 4.89). Verbal IQ scores did not seem to be associated with manganese exposure indicators.

CONCLUSIONS: Drinking water manganese levels were considerably lower than in previous studies reporting neurotoxic effects. There was no clear indication of an association between exposure to manganese and cognitive development in this sample of school-age children although the data suggest there might be sex-specific associations. Given the low levels of exposure and sex-specific associations, a larger sample size would have been required to increase the statistical power and better characterize the relations.

Manganese in Drinking Water and Cognitive Abilities

Rahman SM, Kippler M, Tofail F, Bölte S, Derakhshani Hamadani J, Vahter M. Manganese in Drinking Water and Cognitive Abilities and Behavior at 10 Years of Age: A Prospective Cohort Study. Environmental health perspectives. 2017 May 26;125(5):057003. doi: 10.1289/EHP631.

BACKGROUND: Cross-sectional studies have indicated impaired neurodevelopment with elevated drinking water manganese concentrations (W-Mn), but potential susceptible exposure windows are unknown.

OBJECTIVES: We prospectively evaluated the effects of W-Mn, from fetal life to school age, on children’s cognitive abilities and behavior.

METHODS: We assessed cognitive abilities and behavior in 1,265 ten-year-old children in rural Bangladesh using the Wechsler Intelligence Scale for Children (WISC-IV) and the Strengths and Difficulties Questionnaire (SDQ), respectively. Manganese in drinking water used during pregnancy and by the children at 5 y and 10 y was measured using inductively coupled plasma mass spectrometry.

RESULTS: The median W-Mn was (range 0.001-6.6) during pregnancy and  at 10 y. In multivariable-adjusted linear regression analyses, restricted to children with low arsenic (As) exposure, none of the W-Mn exposures was associated with the children’s cognitive abilities. Stratifying by gender (p for interaction in general  showed that prenatal W-Mn was positively associated with cognitive ability measures in girls but not in boys. W-Mn at all time points was associated with an increased risk of conduct problems, particularly in boys (range 24-43% per mg/L). At the same time, the prenatal W-Mn was associated with a decreased risk of emotional problems [odds ratio (OR)=0.39 (95% CI: 0.19, 0.82)] in boys. In girls, W-Mn was mainly associated with low prosocial scores [prenatal W-Mn: OR=1.48 (95% CI: 1.06, 1.88)].

CONCLUSIONS: Elevated prenatal W-Mn exposure was positively associated with cognitive function in girls, whereas boys appeared to be unaffected. Early life W-Mn exposure appeared to adversely affect children’s behavior. 

Manganese Exposure and Neurotoxic Effects in Children

Bjørklund G, Chartrand MS, Aaseth J. Manganese exposure and neurotoxic effects in children. Environ Res. 2017 May;155:380-384. doi: 10.1016/j.envres.2017.03.003. Epub 2017 Mar 10.

Manganese (Mn) is the fifth most abundant metal on earth. Although it is a well understood essential trace element, in excess, Mn is neurotoxic. Initial toxic symptoms associated with Mn are of psychiatric nature and are clinically defined as locura manganica. Neurological signs of Mn toxicity include dystonia, progressive bradykinesia, and disturbance of gait, slurring, and stuttering of speech with diminished volume. Studies indicate that children who ingested Mn in the drinking water (WMn) at or above a level of 0.241mg/L for a minimum of three years performed more poorly in school as measured by mastery of language, mathematics, and in their overall grade average. The Mn-exposed children also performed more poorly on a battery of neurobehavioral tests. It was also found a significant association between higher WMn and lower cognitive performance, verbal function, and full-scale intelligence quotient (IQ) scores. Young children appear to make up a vulnerable group in exposed populations. Toxicity of WMn is a problem particularly in areas of industrial waste or where Mn is leaching from the soil into public drinking water. Practical and cost-effective approaches are available to remove Mn from drinking water. It is crucial to protect developing brains against Mn toxicity.

Manganese in Drinking Water Increases from Aerial Spraying of Mancozeb

Keep in mind that the presence of manganese in drinking water does not necessarily mean that a WHO health guideline is needed. Action can be taken at this locality to lower manganese exposure to below the level of health concern by meeting the existing secondary MCL.

Berna van Wendel de Joode, Benoit Barbeau, Maryse F. Bouchard, Ana María Mora, Åsa Skytt, Leonel Córdoba, Rosario Quesada, Thomas Lundh, Christian H. Lindh, Donna Mergler. Manganese concentrations in drinking water from villages near banana plantations with aerial mancozeb spraying in Costa Rica: Results from the Infants’ Environmental Health Study. Environmental Pollution, Volume 215, August 2016, Pages 247-257.

Elevated manganese (Mn) in drinking water has been reported worldwide. While, naturally occurring Mn in groundwater is generally the major source, anthropogenic contamination by Mn-containing fungicides such as mancozeb may also occur. The main objective of this study was to examine factors associated with Mn and ethylenethiourea (ETU), a degradation product of mancozeb, in drinking water samples from villages situated near banana plantations with aerial spraying of mancozeb. Drinking water samples (n = 126) were obtained from 124 homes of women participating in the Infants’ Environmental Health Study (ISA, for its acronym in Spanish), living nearby large-scale banana plantations. Concentrations of Mn, iron (Fe), arsenic (As), lead (Pb), cadmium (Cd) and ethylenethiourea (ETU), a degradation product of mancozeb, were measured in water samples. Only six percent of samples had detectable ETU concentrations (limit of detection (LOD) = 0.15 μg/L), whereas 94% of the samples had detectable Mn (LOD = 0.05 μg/L). Mn concentrations were higher than 100 and 500 μg/L in 22% and 7% of the samples, respectively. Mn was highest in samples from private and banana farm wells. Distance from a banana plantation was inversely associated with Mn concentrations, with a 61.5% decrease (95% CI: −97.0, −26.0) in Mn concentrations for each km increase in distance. Mn concentrations in water transported with trucks from one village to another were almost 1000 times higher than Mn in water obtained from taps in houses supplied by the same well but not transported, indicating environmental Mn contamination. Elevated Mn in drinking water may be partly explained by aerial spraying of mancozeb; however, naturally occurring Mn in groundwater, and intensive agriculture may also contribute. Drinking water risk assessment for mancozeb should consider Mn as a health hazard. The findings of this study evidence the need for health-based World Health Organization (WHO) guidelines on Mn in drinking water.

Manganese Deposition in Drinking Water Distribution Systems

Gerke TL, Little BJ, Barry Maynard J. Manganese deposition in drinking water distribution systems. The Science of the total environment. 2015 Sep 23;541:184-193. doi: 10.1016/j.scitotenv.2015.09.054.

This study provides a physicochemical assessment of manganese deposits on brass and lead components from two fully operational drinking water distributions systems. One of the systems was maintained with chlorine; the other, with secondary chloramine disinfection. Synchrotron-based in-situ micro X-ray adsorption near edge structure was used to assess the mineralogy. In-situ micro X-ray fluorescence mapping was used to demonstrate the spatial relationships between manganese and potentially toxic adsorbed metal ions. The Mn deposits ranged in thickness from 0.01 to 400μm. They were composed primarily of Mn oxides/oxhydroxides, birnessite (Mn3+ and Mn4+) and hollandite (Mn2+ and Mn4+), and a Mn silicate, braunite (Mn2+ and Mn4+), in varying proportions. Iron, chromium, and strontium, in addition to the alloying elements lead and copper, were co-located within manganese deposits. With the exception of iron, all are related to specific health issues and are of concern to the U.S. Environmental Protection Agency (U.S. EPA). The specific properties of Mn deposits, i.e., adsorption of metals ions, oxidation of metal ions and resuspension are discussed with respect to their influence on drinking water quality.

Baltimore (MD) tackling high manganese…

Loch Raven Reservoir experiencing higher than usual manganese, which is a key water source for Harford County as well as Baltimore City and County.

click here for news article….