Chronic manganism: fourteen years of follow-up

Spatial analysis and human health risk assessment of elements in ground water of District Hyderabad, Pakistan using ArcGIS and multivariate statistical analysis

Availability of clean drinking water is a basic necessity of human population. Therefore, the current study was taken up for spatial analysis and human health risk assessment of elements in Ground water of District Hyderabad, Pakistan. Evaluation of 10 potential hazardous elements in one hundred eighteen samples of ground water from district Hyderabad, Pakistan was done to assess their natural and anthropogenic origin and possible effects on living organisms and human health. Based on statistical tools of Pearson Co-relation, Metal Clustering and Principal Component Analysis (PCA), three groups of elements were produced; First group included Mn, Fe, B and Cr, the second group contained Cu, Ni and As while third group included Pb, Cd and Zn. Higher Relative Standard Deviation (RSD) values of Cu, Ni, As, Pb, Cd and Zn showed their anthropogenic origin while Mn, Fe, B and Cr were found with lower concentration that indicated their natural origin. Histograms and box-plots of Mn, Fe, B and Cr were found to be normally distributed while these parameters were appeared abnormal for Cu, Ni, As, Pb, Cd and Zn. Risk assessment was quantified by hazard quotient (HQ) and cancer risk for both adult and child. Non-carcinogenic risks as depicted by HQs of all the 10 metal(loid)s were below the recommended HQ threshold of 1 for both child and adult. However, highest HQ was calculated for B (child 0.300 and adult 0.338) followed by the values for Mn and Ni. The potential risks of combined effect of all the 10 metal(loid)s through ingestion of groundwater was assessed using HI and calculated to be 0.694 for adult and 0.566 for child. This indicates the potential health risk of these metal(loid)s to human due to the consumption of the groundwater of district Hyderabad for drinking purpose. Considering the geometric mean for the studied area, carcinogenic risk of As through oral intake was calculated i.e. 1.50 × 10^-4 and 2.62 × 10^-5 for the adult and child However, this carcinogenic risk is 1.91 × 10^-5 and 3.28 × 10^-6 for Cd in adult and child and 1.94 × 10^-3 and 3.32 × 10^-4 for Cr in adult and child, respectively. Since the cancer risk 6exceeded the target risk of 1 × 10^-4 for Cr i.e. 1.94 × 10^-3 in adult, it can thus be considered as 'non-acceptable'. Spatial maps of elements produced by ArcGIS showed the hotspots of potential hazardous elements such as highest concentration of elements like Zn, Pb and Cd was found in urban areas while highest concentration of Cu, Ni and As was observed near Phulleli canal which passes from Hyderabad City and may contain contamination from waste material of residential area due to their anthropogenic activities.

Chronic Manganese Exposure and the Enteric Nervous System: An in Vitro and Mouse in Vivo Study

BACKGROUND

Chronic environmental exposure to manganese (Mn) can cause debilitating damage to the central nervous system. However, its potential toxic effects on the enteric nervous system (ENS) have yet to be assessed.

OBJECTIVE

We examined the effect of Mn on the ENS using both cell and animal models.

METHOD

Rat enteric glial cells (EGCs) and mouse primary enteric cultures were exposed to increasing concentrations of Mn and cell viability and mitochondrial health were assessed using various morphological and functional assays. C57BL/6 mice were exposed daily to a sublethal dose of Mn (15mg/kg/d) for 30 d. Gut peristalsis, enteric inflammation, gut microbiome profile, and fecal metabolite composition were assessed at the end of exposure.

RESULTS

EGC mitochondria were highly susceptible to Mn neurotoxicity, as evidenced by lower mitochondrial mass, adenosine triphosphate-linked respiration, and aconitase activity as well as higher mitochondrial superoxide, upon Mn exposure. Minor differences were seen in the mouse model: specifically, longer intestinal transit times and higher levels of colonic inflammation.

CONCLUSION

Based on our findings from this study, Mn preferentially induced mitochondrial dysfunction in a rat EGC line and in vivo resulted in inflammation in the ENS. https://doi.org/10.1289/EHP7877.

Association of exposure to manganese and fine motor skills in welders - Results from the WELDOX II study

The aim of this study was to evaluate the effect of exposure to manganese (Mn) on fine motor functions. A total of 48 welders and 30 unexposed workers as controls completed questionnaires, underwent blood examinations, and a motor test battery. The shift exposure of welders to respirable Mn was measured with personal samplers. For all subjects accumulations of Mn in the brain were assessed with T1-weighted magnetic resonance imaging. Welders showed normal motor functions on the Movement Disorder Society-Sponsored Revision of the Unified Parkinson Disease Rating Scale part III. Furthermore welders performed excellent on a steadiness test, showing better results than controls. However, welders were slightly slower than controls in motor tests. There was no association between fine motor test results and the relaxation rates R1 in globus pallidus and substantia nigra as MRI-based biomarkers to quantify Mn deposition in the brain.

Monte Carlo simulation-based probabilistic health risk assessment of metals in groundwater via ingestion pathway in the mining areas of Singhbhum copper belt, India

Probabilistic health risk assessment was conducted for metal exposure through groundwater in mining areas of Singhbhum Copper Belt, India. The concentrations of metals showed notable spatial variation exceeding drinking water standards at some of the locations. Hazard Quotient revealed that chronic risks to the local population were largely contributed by Mn, Co and As. The 95^th percentiles of Hazard Index (HI) calculated using Monte Carlo simulations showed that the HI for male, female and child populations was 2.87, 2.54 and 4.57 for pre-monsoon, 2.16, 1.88 and 3.49 for monsoon and 2.28, 2.02 and 3.75 for post-monsoon seasons, respectively. The Hazard Indices indicated that amongst the populations, risk was greater for child population and considering the seasons the risk was higher during the pre-monsoon season. The sensitivity analysis suggested that concentration of metals in groundwater and exposure duration were 2 most influential input variables that contributed to the total risk.

Manganese toxicity in critical care: Case report, literature review and recommendations for practice

We present the case of a 62-year-old man on the intensive care unit with pancreatitis. Since early in his admission, and for the remainder of his prolonged stay in intensive care, he has received parenteral nutrition for intestinal failure. The whole blood manganese concentration was significantly increased after 2½ months of parenteral nutrition (PN). Three months into his stay, he developed a resting tremor and extra-pyramidal dyskinesia. In the absence of other neurological symptoms, and with no history of essential tremor, Parkinsonism or cerebral signs, hypermanganesaemia was presumed to be the cause. We review manganese metabolism and toxicity in patients who are fed with parenteral nutrition and review the current recommendations and guidelines.

Human health risk assessment via drinking water pathway due to metal contamination in the groundwater of Subarnarekha River Basin, India

Groundwater samples were collected from 30 sampling sites throughout the Subarnarekha River Basin for source apportionment and risk assessment studies. The concentrations of As, Ba, Cd, Cr, Co, Cu, Fe, Mn, Mo, Ni, Se, Sr, V and Zn were determined using inductively coupled plasma-mass spectrometry (ICP-MS). The results demonstrated that concentrations of the metals showed significant spatial variation with some of the metals like As, Mn, Fe, Cu and Se exceeding the drinking water standards at some locations. Principal component analysis (PCA) outcome of four factors that together explained 84.99 % of the variance with >1 initial eigenvalue indicated that both innate and anthropogenic activities are contributing factors as source of metal in groundwater of Subarnarekha River Basin. Risk of metals on human health was then evaluated using hazard quotients (HQ) and cancer risk by ingestion for adult and child, and it was indicated that Mn was the most important pollutant leading to non-carcinogenic concerns. The carcinogenic risk of As for adult and child was within the acceptable cancer risk value of 1 × 10(-4). The largest contributors to chronic risks were Mn, Co and As. Considering the geometric mean concentration of metals, the hazard index (HI) for adult was above unity. Considering all the locations, the HI varied from 0.18 to 11.34 and 0.15 to 9.71 for adult and child, respectively, suggesting that the metals posed hazard by oral intake considering the drinking water pathway.

State-of-the-science review: Does manganese exposure during welding pose a neurological risk?

Recent studies report that exposure to manganese (Mn), an essential component of welding electrodes and some steels, results in neurotoxicity and/or Parkinson's disease (PD) in welders. This "state-of-the-science" review presents a critical analysis of the published studies that were conducted on a variety of Mn-exposed occupational cohorts during the last 100 yr, as well as the regulatory history of Mn and welding fumes. Welders often perform a variety of different tasks with varying degrees of duration and ventilation, and hence, to accurately assess Mn exposures that occurred in occupational settings, some specific information on the historical work patterns of welders is desirable. This review includes a discussion of the types of exposures that occur during the welding process--for which limited information relating airborne Mn levels with specific welding activities exists--and the human health studies evaluating neurological effects in welders and other Mn-exposed cohorts, including miners, millers, and battery workers. Findings and implications of studies specifically conducted to evaluate neurobehavioral effects and the prevalence of PD in welders are also discussed. Existing exposure data indicate that, in general, Mn exposures in welders are less than those associated with the reports of clinical neurotoxicity (e.g., "manganism") in miners and smelter workers. It was also found that although manganism was observed in highly exposed workers, the scant exposure-response data available for welders do not support a conclusion that welding is associated with clinical neurotoxicity. The available data might support the development of reasonable "worst-case" exposure estimates for most welding activities, and suggest that exposure simulation studies would significantly refine such estimates. Our review ends with a discussion of the data gaps and areas for future research.

Effective treatment of manganese-induced occupational Parkinsonism with p-aminosalicylic acid: a case of 17-year follow-up study

OBJECTIVE

Chronic manganese (Mn) intoxication induces syndromes resembling Parkinson disease. The clinical intervention has largely been unsuccessful. We report a 17-year follow-up study of effective treatment of occupational Mn parkinsonism with sodium para-aminosalicylic acid (PAS).

METHODS

The patient, female and aged 50 at the time of treatment, was exposed to airborne Mn for 21 years (1963-1984). The patient had palpitations, hand tremor, lower limb myalgia, hypermyotonia, and a distinct festinating gait. She received 6 g PAS per day through an intravenous drip infusion for 4 days and rested for 3 days as one therapeutic course. Fifteen such courses were carried out between March and June 1987.

RESULTS

At the end of PAS treatment, her symptoms were significantly alleviated, and handwriting recovered to normal. Recent follow-up examination at age 67 years (in 2004) showed a general normal presentation in clinical, neurologic, brain magnetic resonance imaging, and handwriting examinations with a minor yet passable gait.

CONCLUSIONS

This case study suggests that PAS appears to be an effective drug for treatment of severe chronic Mn poisoning with a promising prognosis.

Parkinsonism due to manganism in a welder: neurological and neuropsychological sequelae

A 33-year-old welder with 3 years of exposure to manganese (Mn) bearing welding fumes was seen by neurologists for cognitive and motor complaints. He exhibited signs and symptoms of Parkinson's disease, including tremor, bradykinesia, gait disturbance and cogwheel rigidity. However, he was young and had significant inattention and forgetfulness, had found levodopa unhelpful and moved with a cock-walk gait, all of which suggested manganism. His serum and urine levels of Mn were, in fact, elevated, and his brain MRI had increased T1-weighted signal intensities in the basal ganglia bilaterally (globus pallidus) consistent with Mn deposition. Two years later, he underwent comprehensive neuropsychological testing. Clinical history indicated a mild tremor and emotional dysfunction with irritability, anxiety, and depression with psychotic features. He showed deficits in cognitive flexibility, information processing and speed, and greatly reduced motor speed, which are consistent with a fronto-subcortical process. These findings support a diagnosis of early onset parkinsonism from welding.

Methodological Problems in the Neuropsychological Assessment of Effects of Exposure to Welding Fumes and Manganese

Recently, Kaiser (2003) raised concerns over the increase in brain damage claims reportedly due to exposure to welding fumes. In the present article, we discuss methodological problems in conducting neuropsychological research on the effects of welding exposure, using a recent paper by Bowler et al. (2003) as an example to illustrate problems common in the neurotoxicity literature. Our analysis highlights difficulties in conducting such quasi-experimental investigations, including subject selection bias, litigation effects on symptom report and neuropsychological test performance, response bias, and scientifically inadequate casual reasoning.

Serum clozapine levels: a review of their clinical utility

Therapeutic drug monitoring (TDM) is frequently utilized in the treatment of psychiatric conditions, but its clinical application concerning the use of clozapine is unclear. We present three case reports of patients taking clozapine, review the relevant literature, and propose guidelines to aid the clinical use of TDM of clozapine. Due to its complex metabolism, there are significant inter- and intra-individual variations in clozapine serum levels, for a given dose. However, the range of serum levels that corresponds with toxicity remains unclear. Although central nervous system side-effects may correlate with serum level, many adverse effects of clozapine appear to be unrelated, including haematological and cardiac events. There are numerous clinically significant interactions between clozapine and other substances, including prescribed medications, nicotine and caffeine. TDM of clozapine may be of clinical value in certain situations, such as poor clinical response; signs of toxicity; onset of seizures; changes in concurrent medication, caffeine or nicotine; liver disease; and suspected non-compliance. The current literature does not support the routine testing of serum clozapine levels in everyday clinical practice.