Neuropsychological sequelae of exposure to welding fumes in a group of occupationally exposed men

Yang

Journal of Occupational Health

et al. 2006

The Effect of Occupational Exposure to Metals on the Nervous System Function in Welders:Xianliang WANG, et al. MOE Key Laboratory of Environment and Health, School of Public Health, Tongji Medical College, Huazhong University of Science and Technology, China-We explored the relationship between metals exposure and nervous impairment in welders. The metals exposure of 82 welders and 51 operators were evaluated for blood Pb, Cd and Mn by atomic absorption spectrometry, and the nervous system impairment was evaluated with the n e u r o b e h a v i o r a l c o r e t e s t b a t t e r y a n d electromyography. Pb (geometric mean: 117.31 µg/L; range: 0.5-327.6 µg/L) and Cd (geometric mean: 3.54 µg/L; range: 0.2-12.5 µg/L) in welders were significantly higher than those in operators. Welders had higher prevalence of nervous system symptoms and worse standard scores of 8 items such as depressiondejection than operators. Significant difference of nervous performance in welders only existed in different concentration groups of Pb and Mn. The performances of fatigue-inertia and some others had negative correlations with Pb and digit span with Mn. Therefore, the nervous system impairment in welders could be attributed to occupational exposure of Pb and Mn, but not Cd, concomitantly. 1) found increased symptoms in welders were related to decreased scores on tasks measuring verbal learning, visuomotor abilities, visuospatial abilities, information processing and motor efficiency. Another study revealed Mn exposure within the range of 0.01-2.67 mg/m 3 could induce subclinical effects on the nervous system 2) , but only the time for welding or the air concentration of Mn was calculated without biological sample collection in these studies.Pb is also a common neurotoxic agent besides Mn. Cd can cause adverse effects on multiple organs, especially the kidney. These metals can be easily absorbed into the body through the respiratory tract. The cases of serious damage to the nervous system have become rare due to the efforts of health promotion among welders. Due to the variability of work settings for welders, it is almost impossible to assess the exposure to neurotoxic metals by means of one universal indicator. Therefore, it is optimal to resort the co-measurement of several metals in biological samples and examination of the performance of the nervous system with neurobehavioral methods in welders due to the objective and sensitivity of neurobehavioral examination and electroneurophysiological detection.To explore the effects of welding on the nervous system among welders and the relationship between Pb, Cd and Mn in blood and the central and peripheral nervous systems functions, a cross-sectional study was carried out in Hefei, China. Methods SubjectsThe subjects in this study were from two vehicle manufactures located next to each other in a suburb of Hefei, a central city of Anhui province in China. Workers welding longer than 6 months continuously by cluster sampling were subjects of the study. A control group

Section: Discussionsupporting

confidence: 81%

mentioning

confidence: 99%

The Effect of Occupational Exposure to Metals on the Nervous System Function in Welders

Yang

Journal of Occupational Health

et al. 2006

“…For these and other reasons, there is no justification for the conclusion that "neuropsychological testing is an effective means for assessing manganese toxicity." 90 The debate about a possible relationship between welding and PD was fueled by the report of Racette et al, 18 who surveyed 953 parkinsonian patients seen in their neurology specialty clinic between 1996 and 2000 and found that the mean age of 15 welders with PD was 17 years younger (46 years) as compared to PD patients who were not welders (63 years). Although the study did not provide any evidence that welders were more likely to develop PD than the general population, the authors suggested that welding acted to accelerate the onset of PD.…”

Section: How Is the Diagnosis Of Manganese-induced Parkinsonism Confimentioning

confidence: 99%

“…A recent study of 100 male manganese alloy plant workers found no difference in performance of various neuropsychological tests between the workers and controls. 89 One of the most cited studies is that of Bowler et al, 90 who evaluated 76 welders, with occupational history of 25 years, and compared them to 42 controls. The two groups performed similarly on tests of verbal skills, verbal retention, and auditory spans, but welders performed worse than controls on tests of verbal learning, working memory, cognitive flexibility, visuomotor processing speed, and motor efficiency.…”

Section: How Is the Diagnosis Of Manganese-induced Parkinsonism Confimentioning

confidence: 99%

Searching for a relationship between manganese and welding and Parkinson’s disease

Jankovic

2005

Neurology

153

Abstract-Research into the causes of Parkinson disease (PD) has accelerated recently with the discovery of novel gene mutations. The majority of PD cases, however, remain idiopathic and in those cases environmental causes should be considered. Several recent reports have focused on welding and manganese toxicity as potential risk factors for parkinsonism and some have even proposed that welding is a risk factor for PD. The controversy has stimulated this review, the primary aim of which is to critically and objectively examine the evidence or lack of evidence for a relationship among welding, manganese, parkinsonism, and PD. NEUROLOGY 2005;64:2021-2028 Parkinson disease (PD) is one of the most common neurodegenerative disorders, affecting approximately 1 million Americans and 1 to 2% of those over age 60 worldwide.1-3 With the lifetime risk of 2% and an increasing incidence with age, coupled with aging of the population, the prevalence of PD is expected to triple over the next 50 years.Despite the growing number of newly identified genetic causes of parkinsonism, 4,5 in the majority of cases the cause is unknown, hence the enormous interest in the role of environmental factors in various parkinsonian disorders.6,7 While numerous toxins have been found to produce nigrostriatal degeneration in experimental animals, 8 there is no evidence that any environmental toxin causes PD. A variety of environmental and occupational exposures, however, have been implicated in the etiology of PD. These include exposure to well water, pesticides, herbicides, rural living, certain metals, fuel oil, magnetic fields, and employment in the steel/alloy industry, wood/pulp plants, farming, carpentry, cleaning, orchards, planer mill, forestry, logging, mining, as well as certain occupations such as body and fender repairmen, auto painters, railroad and car shop mechanics, and workers in oil and gas fields. [9][10][11][12][13][14][15][16][17] In the recent past, several reports have also suggested that welders may be at a higher risk for developing parkinsonism, and some have even proposed that welding is a risk factor for PD.18,19 These claims have entered the legal system and numerous lawsuits have been filed on behalf of welders alleging that toxic fumes generated by the welding rods have caused not only parkinsonism, but also PD. In this review, we intend to examine the evidence for and against a relationship among welding, manganese, parkinsonism, and PD.With the discovery of new causes of parkinsonism and with the recognition that the same etiology (e.g., a single gene mutation) can be associated with markedly diverse pathology, the traditional view that pathologic examination is the gold standard in the diagnosis of PD has been recently challenged. 20,21 In this review, unless a specific etiologic cause is identified, we will define PD based on clinical-pathologic criteria.22 This approach is supported by several studies demonstrating that when PD is diagnosed clinically by expert parkinsonologists, the autopsy confirms the diagn...

“…Moreover, the finger-tapping test is widely used to evaluate motor function in the upper limbs (6)(7)(8) and the relationship between hand preference and hand skill (9) in healthy individuals and to assess hand skill and coordination (10)(11)(12) for occupations in which the hands are essential. The finger-tapping test is also used for psychomotor evaluations (13)(14)(15)(16)(17)(18)(19)(20).…”

Section: Introductionmentioning

confidence: 99%

Advanced analysis of finger-tapping performance: A preliminary study

Barut¹,

Kızıltan²,

Gelir³

et al. 2012

Balkan Med J

The finger-tapping (FT) test has been used for almost a century to evaluate muscle control and motor ability in the upper extremities (1). This task is frequently used to quantitatively evaluate patients with Parkinson's disease (1), ataxia (2), Alzheimer's disease (3), and Korsakoff syndrome (4), as well as in individuals who have suffered an acute stroke (5). Moreover, the finger-tapping test is widely used to evaluate motor function in the upper limbs (6-8) and the relationship between hand preference and hand skill (9) in healthy individuals and to assess hand skill and coordination (10-12) for occupations in which the hands are essential. The finger-tapping test is also used for psychomotor evaluations (13)(14)(15)(16)(17)(18)(19)(20).The movement involved in single-finger tapping is complex and is affected by visual and auditory stimuli, emotional and physical health, and factors that impact the skeletal and nervous systems. The characterisation of finger-tapping by an average tapping interval or by a tapping rate can only provide a limited amount of information. However, constructing a mathematical function that has the best fit to a series of data points obtained for a complex movement possibly helps to understand the nature of the movement.Various techniques have been used to record the number of tappings in a certain test period and the average time passed between tappings (intertap-interval) in the fingertapping test, including a mechanical counter, an electronic switch, a telegraph key, and a computer keyboard associated with word processing software (7,8). However, the time resolution of these systems is either low or unpredictable. The ability of a system to determine only an average intertap-interval or a tapping speed for a complicated movement results in poor time resolution and carries no information on the time course of the movement. Previous studies on this topic have not considered the temporal changes that occur between consecutive tapping. Therefore, the present study evaluated the time course of average intertap-interval values and the patterns of variation in both the right and left hands of right-handed subjects using the TanTong Finger-Tap system (21,22 The finger-tapping test is a commonly employed quantitative assessment tool used to measure motor performance in the upper extremities. This task is a complex motion that is affected by external stimuli, mood and health status. The complexity of this task is difficult to explain with a single average intertap-interval value (time difference between successive tappings) which only provides general information and neglects the temporal effects of the aforementioned factors.