Post by Admin on Jul 19, 2015 16:55:46 GMT -5
Noted a few articles bringing to attention
toxicity of manganese. See below a few articles
substantiating neurotoxicity from exposure to managanese.
The first article mentions high doses. Exposure to small dose can be toxic
for those who are unable to metabolize, lack certain CYPs enzymes, dysfunctional
pathways. accumulation and so forth.
Med Hypotheses. 2005;65(3):607-16.
Neurotoxicity of inhaled manganese: public health danger in the shower?
Elsner RJ1, Spangler JG.
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Abstract
CONTEXT:
Manganese (Mn) is an essential trace element but is neurotoxic at high doses. Showering with Mn-laden water has never been evaluated as a central nervous system (CNS) delivery vector for Mn, even though intranasally administered Mn in laboratory animals circumvents the blood-brain barrier and passes directly into the brain via olfactory pathways.
OBJECTIVE:
To review the literature on Mn and attempt to quantify potential human CNS exposure to manganese from showering.
DATA SOURCES: www.ncbi.nlm.nih.gov/pubmed/15913899
Abstract
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Int J Environ Res Public Health. 2015 Jul 6;12(7):7519-40. doi: 10.3390/ijerph120707519.
Manganese-Induced Parkinsonism and Parkinson's Disease: Shared and Distinguishable Features.
Kwakye GF1, Paoliello MM2, Mukhopadhyay S3, Bowman AB4, Aschner M5.
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Abstract
Manganese (Mn) is an essential trace element necessary for physiological processes that support development, growth and neuronal function. Secondary to elevated exposure or decreased excretion, Mn accumulates in the basal ganglia region of the brain and may cause a parkinsonian-like syndrome, referred to as manganism. The present review discusses the advances made in understanding the essentiality and neurotoxicity of Mn. We review occupational Mn-induced parkinsonism and the dynamic modes of Mn transport in biological systems, as well as the detection and pharmacokinetic modeling of Mn trafficking. In addition, we review some of the shared similarities, pathologic and clinical distinctions between Mn-induced parkinsonism and Parkinson's disease. Where possible, we review the influence of Mn toxicity on dopamine, gamma aminobutyric acid (GABA), and glutamate neurotransmitter levels and function. We conclude with a survey of the preventive and treatment strategies for manganism and idiopathic Parkinson's disease (PD). www.ncbi.nlm.nih.gov/pubmed/26154659
We systematically searched Medline 11/9/02 and again on 3/9/04. The following search terms were used: manganese, water, drinking water, shower, showering, bath, bathing and inhalation, then combined with "water or drinking water or showering or shower or bathing or inhalation."
STUDY SELECTION:
Animal experimental investigations, human epidemiological studies, and consensus and governmental reports were utilized.
DATA EXTRACTION:
Data were extracted by both authors and extrapolations to humans were calculated by one of us (JGS) controlling for age, length of exposure and known respiratory differences between rats and humans.
DATA SYNTHESIS:
Ann Occup Environ Med. 2013 May 21;25(1):4. doi: 10.1186/2052-4374-25-4.
Manganese neurotoxicity: a focus on glutamate transporters.
Karki P, Lee E, Aschner M1.
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Abstract
Manganese (Mn) is an essential element that is required in trace amount for normal growth, development as well maintenance of proper function and regulation of numerous cellular and biochemical reactions. Yet, excessive Mn brain accumulation upon chronic exposure to occupational or environmental sources of this metal may lead to a neurodegenerative disorder known as manganism, which shares similar symptoms with idiopathic Parkinson's disease (PD). In recent years, Mn exposure has gained public health interest for two primary reasons: continuous increased usage of Mn in various industries, and experimental findings on its toxicity, linking it to a number of neurological disorders. Since the first report on manganism nearly two centuries ago, there have been substantial advances in the understanding of mechanisms associated with Mn-induced neurotoxicity. This review will briefly highlight various aspects of Mn neurotoxicity with a focus on the role of astrocytic glutamate transporters in triggering its pathophysiology. www.ncbi.nlm.nih.gov/pubmed/24472696
During a decade of showering in Mn-contaminated water, models for children and adults show higher doses of aerosolized Mn (3-fold and 112-fold greater, respectively) than doses reported to cause Mn brain deposition in rats.
CONCLUSIONS:
Long-term shower exposure to Mn-laden water may pose a significant risk for CNS neurotoxicity via olfactory uptake in up to 8.7 million Americans. If our results are confirmed, regulatory agencies must rethink existing Mn drinking water standards.