Associations between stressful working conditions and psychosomatic symptoms among Palestinian nurses: a cross-sectional survey.

BACKGROUND: Stressful working conditions among nurses have adverse effects on their physical and mental health. We investigated associations between self-reported stressful working conditions and psychosomatic symptoms among nurses in the Hebron district, occupied Palestinian Territory, and whether there are differences the sexes in the perceptions of working conditions and psychosomatic symptoms. METHODS: We did a cross-sectional survey between Oct 7 and Dec 10, 2012, among registered nurses in all health sectors in Hebron district. A nine-point ordinal scale of working conditions was used to categorise perception of stress as low, medium, or high, and seven psychosomatic symptoms were recorded on a checklist coded as never (0), seldom (1), occasionally (2), or often (3), allowing for a total score between 0 and 21. All analyses were done with STATA (version 10). P values of less than 0·05 were significant. Participation in the study was voluntary, and written informed consent was obtained from each participant. The study was approved by the Regional Committee for Medical and Health Research Ethics, Norway. Permission to do the study was obtained from the Palestinian Ministry of Health. FINDINGS: Among 372 eligible nurses, ten were on extended leave from work, 16 declined to participate, and four had incomplete data, giving a final sample of 342 nurses (92% response rate). 212 (62%) were women and 130 (38%) were men. Low levels of stress were reported by 42 (12%) nurses, medium levels by 206 (60%), and high levels by 94 (28%). The mean score of psychosomatic symptoms for the group was 10·4 (SD 4·02, range 0-21). Scores did not differ significantly between men and women. Mean symptom scores differed between nurses with self-reported highly stressful working conditions and those with low levels of stress (12.6 vs 8.4, difference 4·1, 95% CI 2·7-5·5; p<0·001). Among male nurses, those with self-reported highly stressful working conditions had a mean psychosomatic symptom score of 13.0, compared with that was 7.7 among those working in low-stress conditions (difference 5·3 units, p<0·001). This effect remained significant after adjustment for the covariates age, education, number of children, work schedule, and years of experience (12·6 vs 7·7, difference 4·9 units, 95% CI 2·6-7·2). Among female nurses, the scores among those with high-stress working conditions was 12.4 and for those with low-stress working conditions was 9.0 (difference 3·4 units, p<0·001). After adjustment the difference remained similar (12·4 vs 9·0, difference 3·5 units, 95% CI 1·7-5·3, p<0·001). INTERPRETATION: We found that psychosomatic symptoms increased as self-reported perception of stressful working conditions increased, irrespective of sex. The study had a cross-sectional design and both exposure and outcomes were measured using self-report and, therefore, interpretation of the results should be made with caution. Longitudinal epidemiological studies are recommended. Future studies should investigate whether stressful working conditions affect the quality of patients' care in health services. FUNDING: Norwegian Programme for Development, Research and Education.

Tremor measurements in a 22-year cohort study of workers exposed to hand-held vibrating tools.

OBJECTIVES: The objectives of this cohort study were to evaluate possible long-term effects of occupational exposure to hand-arm vibration (HAV) in terms of increased tremor. The aims were to evaluate whether exposure during follow-up, baseline hand-arm vibration syndrome (HAVS), baseline manual dexterity or current medical conditions or life-style habits might be associated with increased tremor. A further aim was to compare two different activation conditions: postural vs rest tremor. METHODS: Forty men (current age: 60.4 years) who had previously worked as manual workers in a specialized engineering and construction company enrolled in the study. Their hand functions had been examined in 1994. At the baseline examination, 27 had been diagnosed with HAVS, while 13 were not exposed. The follow-up examination in 2016-2017 comprised the CATSYS Tremor Pen® for measuring postural and rest tremor and the Grooved Pegboard Test for assessing manual dexterity. Blood samples were taken for assessing biomarkers that might have impact on tremor. RESULTS: Neither cumulative exposure to HAV during follow-up nor HAVS at baseline were associated with increased tremor. A test for manual dexterity at baseline was significantly associated with increased tremor (Tremor Intensity) at follow-up. Blood markers of current medical conditions and tobacco consumption were associated with increased tremor. Rest tremor frequency was higher than postural tremor frequency (p < 0.001). CONCLUSIONS: The main findings of this 22-year cohort study were no indications of long-term effects on tremor related to HAV exposure and previous HAVS status. However, baseline manual dexterity was significantly associated with increased tremor at follow-up. Activation conditions (e.g., hand position) are important when testing tremor.

Job satisfaction and mental health of Palestinian nurses with shift work: a cross-sectional study.

BACKGROUND: Shift work is associated with sleep disturbances, mental health problems, and job dissatisfaction. Disparities between male and female nurses in the effect of shift work on mental distress and job satisfaction have been scarcely studied. We aimed to examine differences between female and male nurses in the associations between shift work and job satisfaction and mental health. METHODS: In this cross-sectional study, male and female nurses were recruited to rate their job satisfaction on the Generic Job Satisfaction Scale and to complete the General Health Questionnaire (GHQ-30). Associations between shift work, mental distress, and satisfaction were estimated from χ2 tests and linear regression analyses using Stata/IC10. The study was approved by the ministry of health. Written informed consent was provided by all participants. FINDINGS: In 2012, we recruited 372 registered nurses from the Hebron governorate in the occupied Palestinian territory. 28 (8%) nurses were excluded, and the final sample (n=344) included 213 (62%) women and 131 (38%) men. 338 nurses rated their job satisfaction, and 309 nurses completed the GHQ-30. After adjusting for covariates, men with shift work reported significantly lower job satisfaction (ß-coefficient -3·3, 95% CI -6·2 to -0·5) than men with day schedules. Women with shift work reported significantly higher levels of mental distress (3·6, 95% CI 0·3 to 7·0) than women with day schedules. Distress was reported by more women than men, but this difference concerned only nurses working day shifts. No differences in job satisfaction associated with shift work was seen between men and women. We found no demonstrable interaction between sex and shift work for job satisfaction (ß-coefficient -1·6, 95% CI -4·4 to 1·2) or distress (-0·03, 95% CI -5·3 to 5·3). INTERPRETATION: Shift work was associated with low job satisfaction in male nurses and high distress in female nurses. Because the study had a cross-sectional design and both exposure and outcomes were measured using self-report, the results should be interpreted with caution. Further studies should investigate whether shift work affects the quality of patient care. FUNDING: The Norwegian Programme for Development, Research and Education (NUFU; NUFU pro x1 50/2002 and NUFUSM-2008/10232) and The National Norwegian State Education Loan Funds.

Neurobehavioral performance of patients diagnosed with manganism and idiopathic Parkinson disease.

PURPOSE: There is a lack of knowledge about neurobehavioral performance among patients with manganism and how their performance differs from that of idiopathic Parkinson disease patients (PD). This study was initiated with the aim to describe and compare neurobehavioral performance among patients diagnosed with manganism, PD and a group of referents. MATERIALS AND METHODS: Neurobehavioral performance was assessed in 34 patients diagnosed with manganism, 13 with PD, and 43 healthy workers (turners/fitters) who served as the reference group. Seventeen of the manganism patients had also been tested approximately 65 months previously. RESULTS: Manganism patients scored substantially more poorly than referents on tests for motor speed, manual dexterity and balance. They also performed more poorly than the PD patients on the postural sway test. In contrast, the PD patients had higher postural tremor intensity with narrower frequency dispersion than manganism patients. The pattern of neurobehavioral performance was more asymmetrical in PD compared to manganism patients, in particular when testing for tremor intestity, grooved pegboard and static steadiness, indicating lateralized impairment in the PD patients. The amount of bradykinesia was comparable between the patient groups. Neurobehavioral performance deteriorated slightly among 17 manganism patients followed for 65 months compared with the age-related decline among referents. CONCLUSIONS: Patients with manganism had severe bradykinesia and balance disturbances, but only slight postural tremor. In contrast, PD patients had significant postural tremor and bradykinesia, but only slight balance disturbances. Their neurobehavioral performance indicated lateralized impairment, more unilateral. Neurobehavioral performance deteriorated slightly in manganism patients during a 65-month follow-up.

Psychosomatic symptoms among Palestinian nurses exposed to workplace aggression.

BACKGROUND: The study examined associations between workplace aggression (WPA) and psychosomatic symptoms in Palestinian nurses. METHODS: The 341 nurses, (62% females and 38% males), answered a WHO questionnaire and a psychosomatic symptoms checklist. RESULTS: A total of 27.3% of the nurses reported exposure to WPA of any kind within the last 12 months. After adjusting for covariates, female nurses exposed to WPA of any kind and those exposed to verbal aggression reported a higher symptom score: (1.5; 95% confidence interval [CI]: 0.3, 2.7), and (1.4; 95%CI 0.2, 2.6), respectively, than unexposed females. Male nurses exposed to bullying reported a higher symptom score: (3.2; 95%CI 1.0, 5.5) than unexposed males. CONCLUSIONS: Exposure to WPA was associated with higher occurrences of psychosomatic symptoms for both sexes. The female nurses reacted most strongly to verbal aggression or to WPA of any type, while bullying was associated with the male nurses' symptoms.

Tremor and hand-arm vibration syndrome (HAVS) in road maintenance workers.

OBJECTIVES: The aim of this study was to evaluate postural and rest tremor among workers using vibrating hand tools, taking into account the possible effects of toxicants such as alcohol and tobacco. A further aim was to study workers diagnosed with hand-arm vibration syndrome (HAVS) at the time of examination. METHODS: This study comprises 103 road maintenance workers, 55 exposed to vibrating hand tools (age 41.0 years; range 21-62) and 48 referents (age 38.5 years; range 19-64). They were examined with the CATSYS Tremor Pen®. Exposure to vibrating tools and serum biomarkers of alcohol and tobacco consumption were measured. RESULTS: Cumulative exposure to vibrating tools was associated with increased postural (p < 0.01) and rest tremor (p < 0.05) and with a higher Center Frequency of postural tremor (p < 0.01) among smokers and users of smokeless tobacco. Rest tremor Center Frequency was higher than postural tremor frequency (p < 0.001). CONCLUSIONS: The main findings indicate an association between cumulative exposure to hand-held vibrating tools, tremor parameters and consumption of tobacco products. The hand position is important when testing for tremor. Rest tremor had a higher Center Frequency. Postural tremor was more strongly associated with exposure than rest tremor. The finding of increased tremor among the HAVS subjects indicated that tremor might be a part of the clinical picture of a HAVS diagnosis. As with all cross-sectional studies, inferences should be made with caution when drawing conclusions about associations between exposure and possible effects. Future research using longitudinal design is required to validate the findings of the present study.

Workplace aggression, psychological distress, and job satisfaction among Palestinian nurses: A cross-sectional study.

BACKGROUND: Nurses can be exposed to aggressive behavior from patients, patient's relatives, colleagues and visitors. PURPOSE: To determine the prevalence of workplace aggression among Palestinian nurses in the Hebron district and to examine cross-sectional associations between exposure to workplace aggression and the occurrence of psychological distress and job satisfaction. METHODS: Of 372 nurses eligible for the study, 343 were included (response rate of 92.2%). The sample comprised 62% females and 38% males. The participants responded to questions about their socio-demographic status, workplace aggression (WHO questionnaires), psychological distress (General Health Questionnaire, GHQ-30), and job satisfaction (Generic Job Satisfaction Scale). RESULTS: Ninety-three (27.1%) of the respondents reported exposure to workplace aggression of any kind. Seventeen (5%) reported exposure to physical aggression, 83 (24.2%) reported exposure to verbal aggression, and 25 (7.3%) reported exposure to bullying. The patients and the patients' relatives were the main sources of physical and verbal aggression, whereas colleagues were the main source of bullying. Males reported a higher prevalence of bullying than females. Younger nurses reported a higher prevalence of exposure to physical aggression, verbal aggression and bullying. Verbal aggression was associated with more psychological distress. Bullying was associated with lower job satisfaction. CONCLUSIONS: More than a quarter of the nurses reported that they had been subject to some sort of aggression at the workplace. Verbal aggression was associated with higher psychological distress. Workplace bullying was associated with lower job satisfaction. Increased awareness and preventive measures to address this problem among health care workers are warranted.

A twelve-year longitudinal study of neuropsychological function in non-saturation professional divers.

OBJECTIVES: Our main aim was to study the long-term neuropsychological effects of non-saturation diving. Further, we aimed to investigate whether neuropsychological performance was predictive of subsequent diving accidents and diving status. METHODS: In this prospective longitudinal study, we enrolled 50 male diving students (mean age 25.3 years) at a diving school and followed them up six and 12 years later (43 and 37 divers, respectively). At each wave of the study, divers completed a comprehensive neuropsychological test battery and answered questionnaires on cumulative number of dives, incidents of decompression illness (DCI) and professional diver status. RESULTS: At the 12-year follow-up, the divers reported a median number of 455 (range 40-5,604) cumulative dives. Cumulative number of dives was not associated with any adverse neuropsychological effects. However, divers with an incident of DCI performed worse in a memory test (Benton Visual Retention Test) and reported slightly more neuropsychiatric symptoms (Q 16). Diver students who performed well on a blindfolded memory test (tactual performance test) had an increased likelihood of becoming a professional diver 12 years later. CONCLUSIONS: The main findings in the present study support the view that asymptomatic non-saturation divers who have dived under controlled conditions do not have an increased risk of impaired nervous system function, at least not to an extent that can be detected with neuropsychological tests while they still are relatively young. The observed associations between a history of DCI and impaired results in a memory test and reporting of neuropsychiatric symptoms may be due to a nervous system effect caused by DCI. The diver students' ability of problem-solving while they were blindfolded was predictive of their likelihood of becoming a professional diver 12 years later.

Neuromotor function in ship welders after cessation of manganese exposure.

PURPOSE: The aim of the present study was to investigate whether previous long-term exposure to manganese (Mn) via inhalation of welding fumes can cause persistent impairment in neuromotor function even long after cessation of exposure. METHODS: Quantitative tests of tremor, motor speed, manual dexterity, diadochokinesis, eye-hand coordination and postural stability were administered to 17 retired ship welders (mean age 69 years), with mean exposure time 28 years. The welders' exposure had ceased on average 18 years before the study. A cumulative exposure index (CEI) was calculated for each of the former welders. The welders were compared with 21 referents from the same shipyards (mean age was 66 years). RESULTS: Former welders performed less well than referents in the grooved pegboard test, and poorer performance was associated with CEI. The performance in most of the other neurobehavioral tests was similar between groups, but the welders tended to perform slightly better than the referents in tests demanding hand steadiness. The latter finding may be due to a training effect from their former working tasks or selection bias into or out of this occupation. CONCLUSIONS: In the present study of welders with previous welding fume exposure, former welders and referents performed similarly in most of the neurobehavioral tests. Previous adverse effects on the neuromotor system might have ceased, and decreased neuromotor function due to normal aging processes in both groups might have disguised any slight effect of previous Mn exposure. The poorer performance in the grooved pegboard test among welders may indicate an adverse effect on motor function of long-term exposure to Mn, but this finding has to be confirmed by other studies.

Neuropsychological function among workers exposed to aluminum - a mini-review.

Aluminum (Al) is the most common element in nature after oxygen and silicon. Aluminum has been proposed to be a causative agent in the development of neurodegenerative diseases. Aluminum made available via the lungs, as it is in occupational settings, is probably better absorbed than that entering the body via the gastrointestinal tract. Neuropsychological tests are sensitive methods for detecting subtle functional impairment of the nervous system. This minireview is based on a systematic literature search for studies on workers occupationally exposed to aluminum. The tests were categorized as belonging to one of 12 different neuropsychological functions. The level of significance was set at p<0.05. Among the 559 papers identified, 24 fulfilled the inclusion criteria. There were no clear, consistent findings of occupational aluminum exposure being correlated with neuropsychological deficits. However, there was a weak tendency toward worse performances on tests related to information processing speed and a slight tendency toward weaker performances on memory tests for workers exposed to aluminum. The limited number of studies in this field makes it difficult to draw a clear conclusion regarding whether occupational exposure to aluminum increases the risk of altered neuropsychological function.

A neurobehavioral study of current and former welders exposed to manganese.

Neurobehavioral functions were studied in 96 welders currently exposed to the geometric mean (GM) concentration of 121 microg/m(3) (range 7-2322) manganese (Mn) in welding fume (air-Mn) based on the individual mean from two successive days of sampling. They were compared to 96 age-matched referents. The arithmetic mean (AM) concentration of Mn in whole blood (B-Mn) was 8.6 microg/L versus 6.9 microg/L in the referents. Associations between the Digit Symbol and Finger Tapping test scores and B-Mn and air-Mn, respectively, were observed. The welders exposed to the highest air-Mn concentrations (GM 423 microg/m(3) range 204-2322) had statistically significantly poorer Finger Tapping test score as compared to their age-matched referents. The welders with the highest AM concentration of B-Mn (12.6 microg/L) scored statistically significantly poorer on the Digit Symbol test when compared to the age-matched referents (AM B-Mn 7.5 microg/L). The same neurobehavioral test battery was applied to 27 patients diagnosed, and financially compensated, as having welding related manganism. They were on average 44.9 (range 34-51) years old at the time of diagnosis, which on average was 5.8 years prior to this study. They had worked as welders for 23.1 years on average (range 15-30). The most affected neurobehavioral functions were associated with impaired Finger Tapping speed and Grooved Pegboard performance. The patients had no alterations in hand tremor as assessed by the CATSYS system, while a few subjects had noticeable tremor as assessed by the Static Steadiness test.

Hand tremor related to smoking habits and the consumption of caffeine in male industrial workers.

Tremor was measured in 49 smokers/snuffers and in 49 non-smokers/non-snuffers in a cross-sectional study. The Kløve-Matthews static steadiness test and TREMOR 7.0 from the CATSYS test system were used to assess the hand tremor. The creatinine (cr) corrected arithmetic mean concentrations of cotinine in urine were 11 microg/g cr (range 0.1-430) in the non-smokers/non-snuffers compared to 1,417 microg/g cr (range 45-3,780) in the smokers/snuffers. The geometric mean urinary caffeine concentrations were 797 microg/g cr (range 0.5-13,330) in the non-smokers/non-snuffers versus 654 microg/g cr (range 0.9-7,470) in the smokers/snuffers. Increased tremor was found in the group of smokers/snuffers compared to the non-smokers/non-snuffers for several parameters on the tremor measurements, e.g. geometric mean tremor intensity of 0.14 m/s(2) (range 0.09-0.40) in the smokers/snuffers versus 0.11 m/s(2) (range 0.07-0.22) in the non-smokers/non-snuffers for the dominant hand were quantified. Also the mean scores on the static steadiness test were inferior in the smokers/snuffers, in particular for the number of touches. The results further indicate that the frequency dispersion is smaller in the smokers/snuffers compared to the non-smokers/non-snuffers. No systematic association was observed between the biomarkers of nicotine and caffeine exposure and the tremor measurements. However, older age appeared to be an important predictor for the magnitude of tremor in the smokers/snuffers, but not in the non-smokers/non-snuffers.

Psychosomatic symptoms and stressful working conditions among Palestinian nurses: a cross-sectional study.

BACKGROUND: High levels of perceived stressful working conditions have been found to have an adverse effect on physical and mental health. OBJECTIVES: To examine the associations between self-reported stressful working conditions and Psychosomatic Symptoms (PSS), and to investigate possible gender differences. METHODS: The present cross-sectional study comprises 430 nurses employed in Hebron district, Palestine. Self-reported stressful working conditions were recorded, and a Psychosomatic Symptoms Check list was used to assess prevalence of PSS. FINDINGS: Median score on the psychosomatic symptom checklist for the group was 11, (range 1-21). Women reported more symptoms than men, with medians 11.6 and 10.0, respectively (p = .0001). PSS were associated with more self-reported stressful working conditions for both men (p < .0001) and women (p < .0001). The association was strongest among men. CONCLUSIONS: PSS were associated with high self-reported stressful working conditions, and this association was strongest among the men.

The Kløve-Matthews static steadiness test compared with the DPD TREMOR. Comparison of a fine motor control task with measures of tremor in smokers and manganese-exposed workers.

The aim of this study was to compare two tests for tremor/fine motor control as regards their sensitivity in relation to effects on tremor of exposure to manganese and cigarette smoke. One hundred manganese-exposed workers were compared with 100 age-matched referents. The subjects were tested with the Kløve-Matthews static steadiness test (hole tremormeter) and the DPD TREMOR (accelerometer). The manganese-exposed subjects showed increased postural tremor compared to the referents. The tremor had a larger frequency dispersion among the exposed subjects than among the referents as assessed by the TREMOR 7.0 test system, indicating that the tremor had a pattern where the power was burned at a wider spectre of frequencies among the exposed subjects than among the referents. The two tests differed in their ability to demonstrate tremor, depending of the type of exposure (manganese or cigarette smoke). The static steadiness test was better than the TREMOR at discriminating between manganese-exposed subjects and referents while the TREMOR was better at discriminating between smokers and non-smokers than the static steadiness test. The tests also differed in their ability to demonstrate tremor depending on the frequency of tremor. The Tremor Intensity I was higher for subjects with higher tremor frequency, while no such effect was found for the static steadiness test parameters. When studying the effects of exposures where the quality of the tremor is unknown, it is suggested to include at least two tremor tests, one based on acceleration and the other on displacement.

A neurobehavioral study of chloralkali workers after the cessation of exposure to mercury vapor.

Neurobehavioral functions were examined in 49 male workers who had been previously exposed to mercury vapor. They were compared with 49 age-matched male referents in a cross-sectional study. The average duration of exposure in the index group was 13.1 years at a calculated mean urinary mercury (U-Hg) concentration of 9.3 nmol Hg/mmol creatinine (Cr.)/year. The exposure had ceased on average 4.8 (range 4.2-10.0) years prior to the examinations. Forty-one exposed participants and 40 referents had also been examined approximately 5 years previously, while they were still under ongoing exposure. The neurobehavioral test scores and the number of subjective symptoms were similar in the previously exposed subjects and the referents. No significant differences in the development of the neurobehavioral test scores were observed between those 41 previously exposed subjects who had also been examined while they were still being exposed when compared to the 40 referents. However, the difference in the Digit Symbol Test scores between the two occasions was associated with the concentration of inorganic mercury in whole blood while they were still under exposure. The results suggest that no long-term effects of mercury vapor exposure are found at the exposure level experienced by these workers. The study may indicate that the test performance on the Digit Symbol Test improves after exposure cessation in the subjects with the highest B-Hg concentrations, and that this test may be quite sensitive to the effects of mercury vapor exposure.

A follow-up study of neurobehavioral functions in welders exposed to manganese.

Welders may be exposed to high amounts of manganese (Mn). In this study 63 welders and 65 referents were followed up with neurobehavioral tests approximately 6 years after the initial examination at baseline. The welders were exposed to the geometric mean (GM) Mn concentration of 116µg/m(3) at baseline and 148µg/m(3) at follow-up. Their mean duration of employments as welders was 19.5 years at follow-up. Being exposed as a welder was associated with a decline between baseline and follow-up in the performance on the Static Steadiness Test, Finger Tapping Test and Grooved Pegboard Test. However, the decline was also associated with having high concentrations of carbohydrate deficient transferrin in serum (sCDT), indicating high alcohol consumption. When subjects with sCDT above the upper reference limit of the laboratory (≥1.7%) were excluded from the analyses, no difference in the decline in performance was observed between welders and referents for any of the applied neurobehavioral tests. Three welders had developed bradykinesia at follow-up, as assessed by a substantial decline in their Finger Tapping Test performance. They had also experienced a severe decline in Foot Tapping, Grooved Pegboard and Postural Sway Test scores (while blindfolded), while postural tremor as assessed with the CATSYS Tremor 7.0 was normal. Their neurobehavioral test performance at baseline 6 years previously had been normal.

Endocrine and immunologic markers in manganese alloy production workers.

OBJECTIVES: The aim of this study was to investigate selected hormones and immunologic markers in manganese alloy production workers with current and long-term manganese exposure. METHODS: One hundred randomly selected male workers exposed to manganese were compared with 100 male referents (matched for age) from similar process industries in a cross-sectional design. RESULTS: The geometric mean of the exposed workers' urinary manganese concentration was 0.9 (range 0.1-126.3) nmol/mmol creatinine (Cr) versus 0.4 (range 0.1-13.1) nmol/mmol Cr for the referents. The mean duration of exposure to manganese was 20.0 (range 2.1-41.0) years. The geometric mean of the prolactin serum concentration was higher for the exposed subjects than for the referents (229 versus 197 mIE/l, P=0.06). Serum prolactin was associated with current exposure to "soluble inhalable manganese", duration of exposure, and smoking habits. The subjects with the longest duration of exposure to manganese or the highest current exposure to "soluble inhalable manganese" had a statistically significantly higher serum prolactin concentration than the referents. The smokers had a lower serum prolactin concentration than the nonsmokers. The concentrations of the measured immunologic markers were similar in the groups. CONCLUSIONS: The study indicates that manganese exposure can increase the serum prolactin concentration. Both duration and current level of exposure are related to the slight increase, which also appears to be modified by current smoking habits. The serum prolactin concentrations were generally within the reference limits of the laboratory and thus not suitable as an exposure marker at these exposure levels.

The interaction between manganese exposure and alcohol on neurobehavioral outcomes in welders.

Neurobehavioral functions were studied in 137 welders exposed to the geometric mean (GM) air concentration of 214 µg/m(3) (range 1-3230) of manganese (Mn) based on the individual mean from two days of air sampling. Only 22 µg/m(3) (GM) was soluble in the artificial lung fluid Hatch solution. The welders were compared to 137 referents (turner/fitters) recruited from the same plants. The GM concentrations of Mn in whole blood (B-Mn) and urine (U-Mn) were 12.8 µg/L and 0.36 µg/g creatinine versus 8.0 µg/L and 0.07 µg/g creatinine in the referents. Alcohol consumption was assessed by measuring carbohydrate deficient transferrin in serum (sCDT). The welders had poorer performance than the referents on the Grooved Pegboard, Finger Tapping, Simple Reaction Time (SRT) and possibly the Maximum Frequency tests. They also reported more subjective symptoms. Welders with sCDT above the upper reference limit had substantially poorer performances on the Grooved Pegboard test, Finger Tapping test and SRT than welders with sCDT below this level. No effect of high sCDT was observed in the referents, indicating an interaction between high sCDT and exposure to Mn for these tests. Self-reported alcohol consumption had no impact on these neurobehavioral test results. A statistically significant difference in the SRT and Grooved Pegboard test results remained after excluding all subjects with sCDT above the normal level, but the difference in test scores between the groups was smaller. These welders also reported more subjective symptoms than the referents. The results suggest that sCDT should be measured in neurobehavioral studies of occupationally Mn exposed populations for a more precise estimation of high alcohol consumption.

The bioavailability of manganese in welders in relation to its solubility in welding fumes.

Blood and urine samples for determination of manganese (Mn) and iron (Fe) concentrations were collected in a cross-sectional study of 137 currently exposed welders, 137 referents and 34 former welders. Aerosol samples for measurements of personal air exposure to Mn and Fe were also collected. The aerosol samples were assessed for their solubility using a simulated lung lining fluid (Hatch solution). On average 13.8% of the total Mn mass (range 1-49%; N = 237) was soluble (Hatch sol), while only 1.4% (<0.1-10.0%; N = 237) of the total Fe mass was Hatch sol. The welders had statistically significantly higher geometric mean concentrations of Mn in whole blood (B-Mn 12.8 vs. 8.0 µg L (-1)), serum (S-Mn 1.04 vs. 0.77 µg L(-1)) and urine (U-Mn 0.36 vs. 0.07 µg g (-1) cr.) than the referents. Statistically significant univariate correlations were observed between exposure to Hatch sol Mn in the welding aerosol and B-Mn, S-Mn and U-Mn respectively. Pearson's correlation coefficient between mean Hatch sol Mn of two days preceding the collection of biological samples and U-Mn was 0.46 (p < 0.001). The duration of employment as a welder in years was also associated with B-Mn and S-Mn, but not with U-Mn. Statistically significantly higher U-Mn and B-Mn were observed in welders currently exposed to even less than 12 and 6 µg m (-3) Hatchsol Mn, respectively. When using the 95(th) percentile concentration among the referents as a cut-point, 70.0 and 64.5% of the most highly exposed welders exceeded this level with respect to B-Mn and U-Mn. The concentrations of B-Mn, S-Mn and U-Mn were all highly correlated in the welders, but not in the referents.