In a cross-sectional study, the serum concentrations of inhibin B and prolactin of 96 male current welders were compared with the concentrations measured in 96 age-matched referents. Also, 23 patients who were all former welders diagnosed as having welding-related manganism were studied. The current welders' geometric mean (GM) airborne exposure to manganese (Mn) was 121 microg m(-3) (range 7-2320). The serum concentrations of prolactin adjusted for age and smoking habits (GM 193 mIU l(-1) vs. 166 mIU l(-1); p=0.047) and inhibin B adjusted for alcohol consumption (arithmetic mean (AM) 151 ng l(-1) vs. 123 ng l(-1); p=0.001) were higher in the welders compared with the referents. The whole blood Mn concentration was associated with the serum prolactin concentrations. Tobacco smoking resulted in lower serum prolactin concentrations. The GM serum prolactin concentrations of the patients did not significantly differ from that of the referents, but their AM serum inhibin B concentration was statistically significantly lower. The results may suggest an effect of Mn on the pituitary that is reversible upon cessation of exposure. Lower inhibin B concentrations in the patients could point to a functional impairment of the testicular Sertoli cells, that may be caused by a welding fume component or other factors in their work environment.
The aim of this study was to evaluate the level of possible cognitive impairment in a cohort of steel workers occupationally exposed to manganese and lead.
Ninety-two employees from an electro-steel works were examined in 1989 and 1995. Fifty-three were re-examined in 2003. Median age of the participants was 53 years, median duration of employment was 24 years, median blood manganese in 1989 and 1995 was 148 and 171 nmol/l, respectively, and median blood lead in 1989 was 0.79 micromol/l. Non-participants were comparable with participants, although they had a higher level of blood manganese in 1989 (186 nmol/l) and 1995 (186 nmol/l). Manganese level in the air was estimated below 1.9 mg/m3 in the 1970s. In the 1990s, manganese level in the air was below 0.28 mg/m3 in the majority of measurements.
Cognitive function was examined with the Cognitive Function Scanner, a computer-based neuropsychological test battery. From a published set of norms a subgroup (n=106) matched for gender, age and social status was extracted and used for comparison.
Learning and memory, visuomotor and visuospatial function, concentration, attention, perception and vigilance were examined. Despite many statistically significant differences between the groups, it was not possible to interpret the results for the steel workers as being better or worse. In a visuomotor subtest, the pen-to-point test, the steel workers were much less accurate than the comparison group. This could be the result of an impaired ability to make fast accurate movements. There were no associations between pen-to-point test results and duration of employment or blood levels of manganese and lead.
Intellectual impairment could not be shown with the Cognitive Function Scanner in this cohort of low to moderate manganese and lead exposed steel workers. A slight subclinical impairment of the visuomotor function was possibly found.
This paper describes the strategy developed in Quebec to deal with an emerging problem: manganism in welders. Only two cases of manganism had been reported to the Commission de la santé et de la sécurité du travail (CSST, Workers Compensation Board in Quebec) before 2000. In the fall of 2001, the CSST was informed of a possible cluster of manganism and received 20 compensation claims from one plant. Action was rapidly taken to understand and tackle this emerging problem. Under the leadership of the CSST, a coordinating working group implemented medical and environmental subcommittees involving representatives of the different partners of the prevention network. After a literature review to document the health risks associated with manganese and the lack of some important information, a panel of international experts was formed to try to reach agreement on the parameters to consider in the diagnosis and management of manganism. The CSST compensation management policies would be adjusted accordingly. Simultaneously, all the available industrial hygiene data were analyzed to estimate where and at what levels workers were exposed to manganese. To complete these data, the exposure of workers in more than 50 industrial plants was evaluated and existing control measures were documented. All these data have been presented for a revision of the Quebec permissible exposure limit (PEL). In this integrated approach, the next step targets the formation of neurologists and neuropsychologists for a standardized medical evaluation, to complete workplace evaluation in the high risk sectors, inform workers and employers and recommend control measures where required, based on a revised PEL. Many strategies will be used to inform the prevention network (about 1000 people), employers and employees of the risks of overexposure to manganese and of the measures to control exposure in all the plants where workers are susceptible to be exposed to manganese.
Methylcyclopentadienyl manganese tricarbonyl (MMT) is an organic derivative of manganese (Mn) used as an additive in unleaded gasoline. The combustion of MMT leads to the formation of oxides of manganese. The objective of the present study is to predict the environmental levels of Mn and the human exposure in the St-Lawrence ecozone (fluvial section, Quebec, Canada) using an environmental fate/exposure model: GEOTOX. The results of our MMT research program on abiotic and biotic components of the ecosystem and on the human exposure were used to validate the model estimations. Air and surface soil were selected as source terms with an annual Mn input rate in each compartment of 0.083-0.113 mol km-2 d-1 and 0.44-0.87 mol km-2 d-1 respectively (Mn3O4 equivalent). The predicted air, soil, plant, surface water and sediment concentrations were similar (+/- 50%) to values measured in the Montreal region. As expected, the ingestion pathway was the main absorption route for adults (> 99%), with vegetables and fruits contributing almost 80% of the dietary intake of Mn. The multimedia exposure doses for adult men predicted by the model ranged between 0.04 and 0.08 mg kg-1 d-1 compared to 0.004 and 0.201 mg kg-1 d-1 (average = 0.05) for workers from the MMT study. Considering the landscape configuration and the source vectors (air and soil) included in the model, GEOTOX estimations were in good agreement with measured values.
BACKGROUND: Parkinsonian syndrome related to intravenous use of a "designer" psychostimulant, derived from pseudoephedrine using potassium permanganate as the oxidant, has been observed in drug addicts in Estonia. OBJECTIVE: To describe the symptomatology of four young patients, history of drug administration and chemical analysis of a drug batch. METHODS: Mental and motor function and quality of life were scored and ephedrone was analyzed using electrospray mass spectrometry. Manganese content of the final synthetic mixture was analyzed using Inductively Coupled Plasma-Atomic Emission Spectrometry. RESULTS: None of the four cases scored below the dementia threshold in MMSE, while other ratings (UPDRS, H&Y, PDQ-39) corresponded to disabilities seen in relatively advanced Parkinson's disease. The ephedrone yield of the reaction was approximately 44% and the mixture was found to contain 0.6 g/l of manganese. CONCLUSIONS: The cases were exposed to extreme manganese load. Their symptomatology is probably identical to manganism. The role of ephedrone is presently unknown. Physicians must be aware of early signs of manganism in patients within social risk groups.
Cast iron products are alloyed with small quantities of manganese, and foundry furnacemen are potentially exposed to manganese during tapping and handling of smelts. Manganese is a neurotoxic substance that accumulates in the central nervous system, where it may cause a neurological disorder that bears many similarities to Parkinson's disease. The aim of the study was to investigate the sources and levels of manganese exposure in foundry furnacemen by a combined measuring of blood-manganese (B-Mn) and manganese in ambient air (air-Mn).
During a period of 16 months, Air-Mn and B-Mn (denoted 'exposure values') were measured involving 24 furnacemen employed in three small size foundries and 21 scrap recycling workers from one plant. In the study period, 18 furnacemen had B-Mn measured 3-4 weeks after decreasing or stopping exposure (denoted 'post-exposure values'). The reference group for the B-Mn measurements consisted of 90 Danish male subjects.
Furnacemen who work in insufficiently ventilated smelting departments inhale, absorb, and retain significant amounts of manganese in their blood (approx. 2.5-5 microg/l above reference values) despite a generally low measured airborne level of manganese fumes (0.002-0.064 mg/m(3)). The 'exposure values' compared with 'post-exposure values' revealed a significant decrease in the B-Mn (on average 3.7 microg/l) level of the most exposed furnacemen. Two persons in our study were suspected of suffering clinically subacute manganese intoxication as both had B-Mn levels beyond the normal limit (25 and 29 microg/l, respectively). The potential problem disappeared completely after cessation of exposure, and the B-Mn levels decreased to 9.4 and 14.1 microg/l, respectively.
Risk assessment based on combined measurements of B-Mn and air-Mn seems to be valid in the interpretation of workers' hazard. Our study indicates that B-Mn may be a valuable parameter for estimating recent exposure (within 1-2 weeks). However, more knowledge is needed about the B-Mn level and its relation to neurological symptoms.
BACKGROUND: Manganese intoxication may lead to a levodopa-resistant, akinetic-rigid syndrome. A new form of presumed manganese poisoning has been reported in drug-addicted persons from Russia, Ukraine, and Estonia who have intravenously injected self-prepared methcathinone hydrochloride (Ephedrone). PATIENT: A 36-year-old man from Azerbaijan with hepatitis C and only modest hepatic synthetic dysfunction developed rapid-onset, levodopa-resistant parkinsonism with profound hypophonia. CONCLUSION: Ephedronic encephalopathy outside the region of the former Soviet Union may become a more widespread public health problem as a result of global travel and the easy availability of the recipe for synthesis of methcathinone on the Internet.