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Frisbie SH, Mitchell EJ, Sarkar B. Urgent need to reevaluate the latest World Health Organization guidelines for toxic inorganic substances in drinking water. Environ Health 2015; 14:63. [PMID: 26268322 PMCID: PMC4535738 DOI: 10.1186/s12940-015-0050-7] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 07/20/2015] [Indexed: 05/24/2023]
Abstract
The World Health Organization (WHO) has established guidelines for drinking-water quality that cover biological and chemical hazards from both natural and anthropogenic sources. In the most recent edition of Guidelines for Drinking-water Quality (2011), the WHO withdrew, suspended, did not establish, or raised guidelines for the inorganic toxic substances manganese, molybdenum, nitrite, aluminum, boron, nickel, uranium, mercury, and selenium. In this paper, we review these changes to the WHO drinking-water guidelines, examining in detail the material presented in the WHO background documents for each of these toxic substances. In some cases, these WHO background documents use literature reviews that do not take into account scientific research published within the last 10 or more years. In addition, there are instances in which standard WHO practices for deriving guidelines are not used; for example, rounding and other mathematical errors are made. According to published meeting reports from the WHO Chemical Aspects Working Group, the WHO has a timetable for revising some of its guidelines for drinking-water quality, but for many of these toxic substances the planned changes are minimal or will be delayed for as long as 5 years. Given the limited nature of the planned WHO revisions to the inorganic toxic substances and the extended timetable for these revisions, we suggest that governments, researchers, and other stakeholders might establish independent recommendations for inorganic toxic substances and possibly other chemicals to proactively protect public health, or at the very least, revert to previous editions of the Guidelines for Drinking-water Quality, which were more protective of public health.
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Affiliation(s)
- Seth H Frisbie
- Department of Chemistry and Biochemistry, Norwich University, Northfield, VT, USA.
| | - Erika J Mitchell
- Department of Chemistry and Biochemistry, Norwich University, Northfield, VT, USA.
| | - Bibudhendra Sarkar
- Department of Molecular Structure and Function, The Research Institute of The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.
- Department of Biochemistry, University of Toronto, Toronto, ON, Canada.
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152
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Peres TV, Eyng H, Lopes SC, Colle D, Gonçalves FM, Venske DKR, Lopes MW, Ben J, Bornhorst J, Schwerdtle T, Aschner M, Farina M, Prediger RD, Leal RB. Developmental exposure to manganese induces lasting motor and cognitive impairment in rats. Neurotoxicology 2015. [PMID: 26215118 DOI: 10.1016/j.neuro.2015.07.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Exposure to high manganese (Mn) levels may damage the basal ganglia, leading to a syndrome analogous to Parkinson's disease, with motor and cognitive impairments. The molecular mechanisms underlying Mn neurotoxicity, particularly during development, still deserve further investigation. Herein, we addressed whether early-life Mn exposure affects motor coordination and cognitive function in adulthood and potential underlying mechanisms. Male Wistar rats were exposed intraperitoneally to saline (control) or MnCl2 (5, 10 or 20 mg/kg/day) from post-natal day (PND) 8-12. Behavioral tests were performed on PND 60-65 and biochemical analysis in the striatum and hippocampus were performed on PND14 or PND70. Rats exposed to Mn (10 and 20 mg/kg) performed significantly worse on the rotarod test than controls indicating motor coordination and balance impairments. The object and social recognition tasks were used to evaluate short-term memory. Rats exposed to the highest Mn dose failed to recognize a familiar object when replaced by a novel object as well as to recognize a familiar juvenile rat after a short period of time. However, Mn did not alter olfactory discrimination ability. In addition, Mn-treated rats displayed decreased levels of non-protein thiols (e.g. glutathione) and increased levels of glial fibrillary acidic protein (GFAP) in the striatum. Moreover, Mn significantly increased hippocampal glutathione peroxidase (GPx) activity. These findings demonstrate that acute low-level exposure to Mn during a critical neurodevelopmental period causes cognitive and motor dysfunctions that last into adulthood, that are accompanied by alterations in antioxidant defense system in both the hippocampus and striatum.
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Affiliation(s)
- Tanara V Peres
- Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
| | - Helena Eyng
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Samantha C Lopes
- Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Dirleise Colle
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Filipe M Gonçalves
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Débora K R Venske
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Mark W Lopes
- Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Juliana Ben
- Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Julia Bornhorst
- Institute of Nutritional Sciences, University of Potsdam, Nuthetal, Germany
| | - Tanja Schwerdtle
- Institute of Nutritional Sciences, University of Potsdam, Nuthetal, Germany
| | - Michael Aschner
- Department of Molecular Pharmacology, Albert Einstein College of Medicine, Bronx, NY, USA
| | - Marcelo Farina
- Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rui D Prediger
- Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Departamento de Farmacologia, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Rodrigo B Leal
- Programa de Pós-graduação em Neurociências, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil; Departamento de Bioquímica, Centro de Ciências Biológicas, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil.
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153
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Langley RL, Kao Y, Mort SA, Bateman A, Simpson BD, Reich BJ. Adverse neurodevelopmental effects and hearing loss in children associated with manganese in well water, North Carolina, USA. ACTA ACUST UNITED AC 2015; 4:62-69. [PMID: 28344850 PMCID: PMC5364800 DOI: 10.5455/jeos.20150403060427] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Aim Heavy metals such as manganese, arsenic and lead can act as neurotoxins. There have been few human studies of neurobehavioral/neurodevelopmental effects of arsenic and manganese on children in the United States. Since 1998, North Carolina has tested all new private wells for manganese, arsenic and lead. This study was conducted to evaluate adverse neurodevelopmental effects (delayed milestones, speech/language disorders and hearing loss) in children and metal concentrations in well water. Methods A quasi-regression model of the number of children (0–35 months of age) with adverse neurodevelopmental effects as outcome measures and aggregate mean metal concentration (arsenic, lead, and manganese) in private well water in each county as exposures. Results Over 70,000 private well water samples from 1998 to 2011 were analyzed for metal content. From 2008 to 2011, an average of 17,000 children was enrolled in the Infant Toddler Program. On average, 1.7% of children in this age range in each county had a speech/language disorder, 0.24% had a diagnosis of delayed milestones, and 0.026% had a diagnosis of hearing loss. The county mean manganese concentration was significantly and positively associated with the prevalence of delayed milestones and hearing loss in the children. No association was found for metal concentrations and speech/language disorders. Conclusion This ecological study indicates that further investigation of manganese in well water and associated neurodevelopmental health outcomes in children is needed.
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Affiliation(s)
- Ricky L Langley
- Department of Health and Human Services, Raleigh, North Carolina, USA
| | - Yimin Kao
- Department of Statistics, North Carolina State University, Raleigh, North Carolina, USA
| | - Sandra A Mort
- Department of Health and Human Services, Raleigh, North Carolina, USA
| | - Allen Bateman
- Department of Health and Human Services, Raleigh, North Carolina, USA; Centre for Infectious Disease Research in Zambia, Lusaka, Zambia; Department of Infectious Diseases, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Barbara D Simpson
- Department of Health and Human Services, Raleigh, North Carolina, USA
| | - Brian J Reich
- Department of Statistics, North Carolina State University, Raleigh, North Carolina, USA
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