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PubMed2006

The risk of pterygium in salt workers.

PURPOSE: To find out if exposure to direct and reflected sunlight in brine pans (ground water rich in salt, kept in wide pans in open air for salt manufacturing), increases the risk of pterygium in exposed salt workers. METHODS: It was a cross sectional observational study, in which 865 salt workers were examined in the Free Occupational Health Check-up camps held near salt sites; 304 persons from the same area engaged in other work were examined as controls. The prevalence of pterygium in different age groups was compared between brine workers (who worked in the brine pans), dry salt workers, (who were engaged in the loading, weighing, milling, packing or transportation of the dry salt but never worked in brine pans) and non-salt-worker controls. RESULTS: The prevalence of pterygium was significantly higher in brine workers (21.0%) as compared to dry salt workers (9.1%) (Yates corrected chi(2) = 23.45, p = 0.000001) and non-salt-worker controls (9.4%) (Yates corrected chi(2) = 15.69, p = 0.00007). It increased with age and duration of employment in the salt industry. CONCLUSIONS: Brine workers have a higher risk of developing pterygium probably due to their exposure to sunlight reflected both from the surface of brine and from the surface of salt crystals.

Adult↗
PubMed1985

Workers self-pacing in hot conditions: a case study.

It is not always possible in hot environments, to determine safe work-rest regimens based upon heat stress criteria. Is it then a good health policy to rely upon the self-pacing of the workers? To address this question, we observed the spontaneous work-rest cycles of seven masonry workers allocated to the maintenance of a float-glass furnace and the workers' heart rate and rectal temperature were continuously monitored. Results showed that the regimens adopted by the workers were poorly related to physiological parameters. The duration of each heat exposure was significantly related to the worker aerobic capacity, but not to the heart rate level reached at the end of the working period. Due to self-pacing of the task, heart rates and rectal temperatures remained within acceptable limits for all workers but one, even though these workers were rather old and had a rather low physical capacity. These favourable results may be ascribed to a spontaneous limitation of the effective working time to about 25% of the shift duration and to the fact that subjects worked, in pairs alternately, to perform the task. It is concluded that self-regulation of the work-rest cycles can be an effective means to protect the workers exposed to hot conditions from an excessive physiological strain, providing that the task has no urgent character and does not involve productivity incentives, and that the workers are well trained to their job.

Journal Article↗
PubMed1988

Pulmonary and immunologic evaluation of foundry workers exposed to methylene diphenyldiisocyanate (MDI).

A cross-sectional evaluation was performed of workers in a steel foundry in which methylene diphenyldiisocyanate (MDI) was used as a component of a binder system used to make cores and molds. Preshift and postshift spirometry and clinical evaluations were performed on 26 currently exposed (group I), on six formerly exposed (group II), and on 14 nonexposed workers to MDI (group III). Serum samples were assayed for total antibody binding, specific IgG by ELISA, and specific IgE by the RAST method to MDI-human serum albumin (HSA). Symptoms compatible with occupational asthma were elicited from seven (27%) of 26 group I workers and from three of six group II workers. No symptoms were reported by group III workers. Intrashift change in FEV1 (a mean decrease of 0.049 L) in group I workers was significantly decreased compared to that in unexposed group III workers (a mean increase of 65 ml; p = 0.043). Specific IgG and total antibody responses to MDI-HSA were detected only in workers with current or former exposure to MDI. Only one worker was identified with IgE-mediated occupational asthma exhibiting a positive prick test and elevated RAST to MDI-HSA of 25.5% bound. In this occupational setting, polyclonal immune responses to MDI-HSA and clinical sensitization to MDI were demonstrated to occur.

Adult↗
PubMed1991

The impact of vendorship legislation and interprofessional competition in the market for social workers' services.

The results of this article suggest that, in the short run, vendorship legislation will not result in a large shift of social workers from organized settings into private practice. However, vendorship legislation appears to increase the number of social workers in private practice in areas that have not attracted as many psychiatrists. Thus, vendorship may have a favorable impact on the geographic distribution of mental health providers. Vendorship legislation may result in increases in private practice social workers in underserved areas. The results also suggest that social workers and psychiatrists compete in the market for mental health services. In counties with higher psychiatrist-to-population ratios, fees for social workers' services are lower. Further, in counties with higher psychiatrist-to-population ratios, the number of social workers in private practice decreased after vendorship. Finally, there is a large range of optimal practice size for social workers. Social workers with 20 or more clients per month can provide mental health services at the lowest average cost per client. Thus social workers operating either full-time or part-time practices with more than 20 clients per month can provide mental health services efficiently.

Cost Control↗
PubMed1995

DNA damage in mononuclear blood cells of metal workers exposed to N-nitrosodiethanolamine in synthetic cutting fluids.

In 28 smoking and 37 non-smoking male metal workers from 7 small to medium sized plants the genotoxic effect caused by the occupational exposure measured as DNA single strand breaks in the peripheral mononuclear blood cells was investigated. Metal workers using synthetic cutting fluids are possibly exposed to the carcinogenic N-nitrosodiethanolamine (NDELA). In this investigation NDELA was detected in the air of the working halls in a concentration up to 1000 ng/m3 and in the cutting fluids in a concentration up to 135 mg/l (mean values per plant). Workers staying in rooms with a mean concentration of NDELA in the air of about 1 microgram/m3 revealed two times more DNA strand breaks than workers staying in an environment with less than 50 ng/m3 of NDELA (p < 0.01). Non-smoking workers with more than 4.5 h contact to cutting fluids per day showed an 1.5 times higher mean level of DNA strand breaks than their nonsmoking colleagues having had less than 4.5 h contact to cutting fluids (p < 0.02). Also workers having had work place-related complaints showed a statistically significantly higher level of DNA strand breaks compared to workers with no or no work place-related complaints. No significant correlation was obtained between the extent of DNA damage and the estimated extent of skin contact or the concentration of NDELA found in the cutting fluids. Therefore, for workers in this investigation NDELA incorporated by inhalation is probably more relevant for genotoxic damage than NDELA resorbed by skin. An increased level of DNA damage was found in metal workers depending on the concentration of NDELA in the air of the work places. However, without further investigations it cannot be excluded that also other concomitant agents in the environment were responsible for the observed genotoxic effect.

Adult↗
PubMed1984

Risks, survival and trends of malignant melanoma among white and blue collar workers in Sweden.

All persons in Sweden, classified as white or blue collar workers in the 1960 Population Census, were followed up for the period 1961-1973 with regard to the occurrence of cancer. The SMRs were calculated for 50 tumour sites and it was found that the crude classification of occupations into white or blue collar workers was particularly important for malignant melanoma risk. The number of malignant melanoma cases among blue collar workers was significantly lower than expected while it was significantly higher than expected among the white collar workers. This was true for men as well as for women. The SMRs were calculated to be 87 and 141 (men) and 79 and 117 (women), respectively. Comparing the relative survival probabilities it was found that white collar workers had a higher probability of survival than blue collar workers. This might indicate that the difference in occurrence could be dependent on early detection as well as differential risk. The incidence of malignant melanoma is increasing faster than any other kind of tumour in Sweden. For the period 1961-1970 the incidence rate increased two-fold for blue collar workers and more than two-fold for white collar workers (men). In absolute terms the white collar workers in the age group 45-64 had an appreciably faster increase in incidence over this period compared to all other groups studied.

Adult↗
PubMedDate not supplied

Effects of smoking and lead exposure on proximal tubular integrity among Egyptian industrial workers.

BACKGROUND: The hazards of occupational lead exposure are well documented. Tissue damage produced by lead is slow and progressive. The renal system is one of the systems primarily affected by lead. The present study aimed to evaluate renal proximal tubular functional and structural integrity among lead-exposed and cigarette-smoking male Egyptian workers. This study was extended to investigate the effect of lead exposure and cigarette smoking on urinary excretion of copper (Cu) and zinc (Zn). METHODS: Participants included in the present study were 156 male workers grouped as follows: i) 75 lead non-exposed workers subgrouped into G1 that consisted of 36 non-smokers (age, 39.08+/-6.65 years) and G2, which included 39 smokers (age, 43.87+/-9.93 years); ii) 45 lead-exposed workers (work duration <20 years) subgrouped into G3 that consisted of 25 non-smokers (age, 37.40+/-3.76 years) and G4, which included 20 smokers (age, 38.40+/-4.95 years), and iii) 36 lead-exposed workers (work duration > or =20 years) subgrouped into G5 that consisted of 16 non-smokers (age, 45.94+/-4.19 years) and G6 which included 20 smokers (age, 45.70+/-2.25 years). Functional integrity of proximal tubules was studied by determining urinary level of low-molecular-weight protein alpha1-microglobulin (alpha1M), and structural integrity was investigated by measuring urinary activities of the lysosomal enzyme N-acetyl-beta-D-glucosaminidase (NAG) and the cytoplasmic enzyme glutathione S-transferase (GST). Urinary concentrations of Pb, Cu, Zn, and creatinine were also determined. RESULTS: Data of the present investigation showed increased urinary excretion of all measured urinary parameters among lead-exposed workers in comparison with non-exposed workers whether they were non-smokers or smokers (G3 vs. G1, G5 vs. G1, G4 vs. G2, and G6 vs. G2), with greater elevation among lead-exposed smokers than among lead-exposed non-smokers (G4 vs. G3, G6 vs. G5). In addition, there was a greater increase in levels of all urinary parameters among workers with work duration > or =20 years than in those with <20 years' work duration (G6 vs. G4, G5 vs. G3). CONCLUSIONS: Lead exposure in Egyptian workers causes damage to renal proximal tubules and results in its dysfunction. Cigarette smoking has a nephrotoxic effect and also is synergistic to lead nephrotoxicity on urinary excretion of GST and NAG, as well as Pb.

Acetylglucosaminidase↗
PubMed2006

Molecular epidemiological studies in 1,3-butadiene exposed Czech workers: female-male comparisons.

Results of a recent molecular epidemiological study of 1,3-butadiene (BD) exposed Czech workers, conducted to compare female to male responses, have confirmed and extended the findings of a previously reported males only study (HEI Research Report 116, 2003). The initial study found that urine concentrations of the metabolites 1,2-dihydroxy-4-(acetyl) butane (M1) and 1-dihydroxy-2-(N-acetylcysteinyl)-3-butene (M2) and blood concentrations of the hemoglobin adducts N-[2-hydroxy-3-butenyl] valine (HB-Val) and N-[2,3,4-trihydroxy-butyl] valine (THB-Val) constitute excellent biomarkers of exposure, both being highly correlated with BD exposure levels, and that GST genotypes modulate at least one metabolic pathway, but that irreversible genotoxic effects such as chromosome aberrations and HPRT gene mutations are neither associated with BD exposure levels nor with worker genotypes (GST [glutathione-S-transferase]-M1, GSTT1, CYP2E1 (5' promoter), CYP2E1 (intron 6), EH [epoxide hydrolase] 113, EH139, ADH [alcohol dehydrogenase]2 and ADH3). The no observed adverse effect level (NOAEL) for chromosome aberrations and HPRT mutations was 1.794 mg/m(3) (0.812 ppm)--the mean exposure level for the highest exposed worker group in this initial study. The second Czech study, reported here, initiated in 2003, included 26 female control workers, 23 female BD exposed workers, 25 male control workers and 30 male BD exposed workers (some repeats from the first study). Multiple external exposure measurements (10 full 8-h shift measures by personal monitoring per worker) over a 4-month period before biological sample collections showed that BD workplace levels were lower than in the first study. Mean 8-h TWA exposure levels were 0.008 mg/m(3) (0.0035 ppm) and 0.397 mg/m(3) (0.180 ppm) for female controls and exposed, respectively, but with individual single 8-h TWA values up to 9.793 mg/m(3) (4.45 ppm) in the exposed group. Mean male 8-h TWA exposure levels were 0.007 mg/m(3) (0.0032 ppm) and 0.808 mg/m(3) (0.370 ppm) for controls and exposed, respectively; however, the individual single 8-h TWA values up to 12.583 mg/m(3) (5.72 ppm) in the exposed group. While the urine metabolite concentrations for both M1 and M2 were elevated in exposed compared to control females, the differences were not significant, possibly due to the relatively low BD exposure levels. For males, with greater BD exposures, the concentrations of both metabolites were significantly elevated in urine from exposed compared to control workers. As in the first study, urine metabolite excretion patterns in both sexes revealed conjugation to be the minor detoxification pathway (yielding the M2 metabolite) but both M1 and M2 concentration values were lower in males in this second study compared to their concentrations in the first, reflecting the lower external exposures of males in this second study compared to the first. Of note, females showed lower concentrations of both M1 and M2 metabolites in the urine per unit of BD exposure than did males while exhibiting the same M1/(M1+M2) ratio, reflecting the same relative utilization of the hydrolytic (producing M1) and the conjugation (producing M2) detoxification pathways as males. Assays for the N,N-(2,3-dihydroxy-1,4-butadyl) valine (pyr-Val) hemoglobin (Hb) adduct, which is specific for the highly genotoxic 1,2,3,4-diepoxybutane (DEB) metabolite of BD, have been conducted on blood samples from all participants in this second Czech study. Any adduct that may have been present was below the limits of quantitation (LOQ) for this assay for all samples, indicating that production of this important BD metabolite in humans is below levels produced in both mice and rats exposed to as little as 1.0 ppm BD by inhalation (J.A. Swenberg, M.G. Bird, R.J. Lewis, Future directions in butadiene risk assessment, Chem. Biol. Int. (2006), this issue). Results of assays for the HB-Val and THB-Val hemoglobin adducts are pending. HPRT mutations, determined by cloning assays, and multiple measures of chromosome level changes (sister-chromatid exchanges [SCE], aberrations determined by conventional methods and FISH) again showed no associations with BD exposures, confirming the findings of the initial study that these irreversible genotoxic changes do not arise in humans occupationally exposed to low levels of BD. Except for lower production of both urine metabolites in females, no female-male differences in response to BD exposures were detected in this study. As in the initial study, there were no significant genotype associations with the irreversible genotoxic endpoints. However, as in the first, differences in the metabolic detoxification of BD as reflected in relative amounts of the M1 and M2 urinary metabolites were associated with genotypes, this time both GST and EH.

Acetylcysteine↗
PubMed2006

Classification of worker exposures.

The classification of jobs or workers by exposure is an important undertaking in any occupational epidemiological study. Hitherto, the exposure classification designs have been strongly motivated by a desire to generate a sufficient number of exposure classes for the determination of a potential exposure-response relationship. Thus, the partitioning of exposures has been more or less arbitrary. The misclassification problems created by the selection of an arbitrary number of exposure assignment classes have not been addressed. In any quantitative exposure classification scheme, specific job titles may be indistinguishable in existing employment records; therefore, between worker variability must be addressed when characterizing worker exposures. Also, industrial hygiene exposure measurements frequently used to characterize worker exposures are often treated as valid representations of exposures; but they are neither random nor systematic evaluations of worker exposures. As a result they do not represent sampling from the proper exposure stratification of workers. These observations suggest that the selection of exposure groups should be based on a more rigorous examination of the data and its limitations. Considering the probability of any given worker being placed into the proper class as the probability of finding the mean exposure for that worker within the class boundary, the general equations to quantify the misclassification rates for any classification design as well as the exposure class limits and their width for any acceptable misclassification rate are developed. If between worker variability could not be calculated from the available exposure measurements, then it might be estimated from the proper data compiled from the literature. By considering an acceptable level of exposure misclassification, it is possible to calculate the allowable number of exposure classes and the proper partitioning ratio for these classes. Thus, the trade-off between misclassification and number of exposure classes might be a satisfactory solution to this difficulty encountered in occupational epidemiology.

Empirical Research↗
PubMed2006

Incidence of type-2 diabetes mellitus in a large population of Japanese male white-collar workers.

Since occupation, a major socio-economic factor, may be a risk factor for type-2 diabetes mellitus (DM), we compared DM incidence among four groups of white-collar workers in a follow-up study in 13,547 Japanese men. The subjects aged 30-59 years and free from DM at baseline consisted of: (a) 3725 clerical, (b) 5575 technical/professional, (c) 3474 manager/administrative and (d) 774 sales workers. Incident DM was identified by 'fasting serum glucose >or=7.00 mmol/l' or 'under medical treatment for DM'. Hazard ratio (HR) and 95% confidence interval (CI) for incident DM were estimated using clerical workers as the reference group (HR=1.00). Baseline age, body mass index (BMI), drinking, smoking, exercise and education were computed as confounders. During mean follow-up periods of 7.4 years, 176 clerical, 264 technical/professional, 195 manager/administrative and 49 sales workers developed DM (6.0, 6.1, 8.8 and 9.4 per 1000 person-years, respectively). Sales workers aged 40-49 and 50-59 years had increased multivariate-adjusted HRs (95% CIs) of 1.55 (1.02, 2.35) and 2.01 (0.98, 4.10), respectively. Manager/administrative workers aged 50-59 years had an increased crude HR (95% CI) of 1.64 (1.02, 2.63), but the significance disappeared after BMI-adjustment (HR (95% CI: 1.46 (0.91, 2.35)). Technical/professional workers had no significant HR in any model. In conclusion, sales workers in Japan aged >or=40 years may have increased risk for DM (+55 to +100%) independent of BMI, lifestyles and education, and manager/administrative workers aged >or=50 years may have increased risk (about +65%) due to their large BMI.

Adult↗
PubMed2005

Food service workers' self-reported food preparation practices: an EHS-Net study.

This study was conducted by the Environmental Health Specialists Network (EHS-Net), a network of environmental health specialists and epidemiologists at federal and state health agencies, whose mission is to improve environmental health practice. One of EHS-Net's primary goals is to improve the understanding of the underlying causes of foodborne illness using a system-based approach. As part of this ongoing effort, EHS-Net analyzed data from a telephone survey of food service workers designed to increase our understanding of food preparation practices (a cause of foodborne illness) in restaurants. Results indicated that risky food preparation practices were commonly reported. Respondents said that at work they did not always wear gloves while touching ready-to-eat (RTE) food (60%), did not always wash their hands or change their gloves between handling raw meat and RTE food (23% and 33%), did not use a thermometer to check food temperatures (53%), and had worked while sick with vomiting or diarrhea (5%). Several factors were associated with safer food preparation practices. Workers responsible for food preparation reported washing their hands and wearing gloves when handling RTE food more often than workers not responsible for food preparation. Workers who cooked reported changing their gloves more often than workers who did not cook. Older workers and managers reported washing their hands more often than younger workers and non-managers. Workers in chain restaurants more frequently reported using thermometers than workers in independently owned restaurants. This study provides valuable information concerning the prevalence of food preparation practices and factors that may impact those practices. Additional research is needed to better understand those factors.

Adult↗
PubMed2005

Respiratory and general health impairments of workers employed in a municipal solid waste disposal at an open landfill site in Delhi.

The objective of this study was to examine the respiratory and general health of workers employed in a municipal solid waste (MSW) disposal at an open landfill site in India. Ninety-six landfill workers of Okhla landfill site, Delhi, and 90 controls matched for age, sex, and socioeconomic conditions were enrolled. Health data was obtained from questionnaire surveys, clinical examination and laboratory investigations. Lung function was evaluated by spirometry. Compared with matched controls, landfill workers had significantly higher prevalences of both upper and lower respiratory symptoms, and they suffered more often from diarrhea, fungal infection and ulceration of the skin, burning sensation in the extremities, tingling or numbness, transient loss of memory, and depression. Spirometry revealed impairment of lung function in 62% of the landfill workers compared to 27% of the controls. Sputum cytology showed squamous metaplasia, abundance of inflammatory cells, alveolar macrophages (AM) and siderophages (macrophages with iron deposits), and high elastase enzyme activity in neutrophils and AM of a majority of landfill workers, indicating adverse cellular lung reaction. Hematological profiles of these workers depicted low hemoglobin and erythrocyte levels with high total leukocyte, eosinophil and monocyte counts. Erythrocytes with target cell morphology were abundant in 42% of the landfill workers compared to 10% of the controls. Toxic granulation in neutrophils, an indication of infection and inflammation, was recorded in 94% of the landfill workers and in 49% of the controls. The results demonstrated higher prevalence of respiratory symptoms, inflammation of the airways, lung function decrement and a wide range of general health problems in MSW disposal workers.

Adult↗
PubMed2005

Genotoxic damage in mine workers exposed to diesel exhaust, and the effects of glutathione transferase genotypes.

This study was performed in an Estonian shale-oil mine with the purpose to develop and apply a number of biomarkers for occupational diesel-exhaust exposure monitoring. Increased breathing-zone exposures to exhaust from operators of diesel-powered trucks in the mine was confirmed in the environmental monitoring part of the study, showing a 7.5-fold higher exposure to particle-associated 1-nitropyrene (1-NP) in 50 underground workers compared with 42 surface workers [P.T.J. Scheepers, D. Coggon, L.E. Knudsen, R. Anzion, H. Autrup, S. Bogovski, R.P. Bos, D. Dahmann, P. Farmer, E.A. Martin, V. Micka, V. Muzyka, H.-G. Neumann, J. Poole, A. Schmidt-Ott, F. Seiler, J. Volf, I. Zwirner-Baier, Biomarkers for occupational diesel exhaust exposure monitoring (BIOMODEM)-a study in underground mining, Toxicol. Lett. 134 (2002) 305-317; P.T.J. Scheepers, V. Micka, V. Muzyka, R. Anzion, D. Dahmann, J. Poole, R.P. Bos, Exposure to dust and particle-associated 1-nitropyrene of drivers of diesel-powered equipment in underground mining, Ann. Occp. Hyg. 47 (2003) 379-388]. Analysis of DNA damage by the Comet assay on frozen blood samples was performed on the total study group and showed significantly higher levels (p=0.003) in underground workers (smokers) driving diesel-powered excavation machines (median 155 on a scale from 0 to 400, among 47 persons), compared with surface workers who smoked (median of 90, among 46 persons). The level of DNA damage in underground smokers was significantly higher (p=0.04) than in non-smokers. Samples from 2 of the 3 sampling weeks had significantly lower DNA damage compared with the third week, probably due to timely processing and freezing. These samples also showed significant differences (p<0.001) between underground workers (median 145, among 41 persons) and surface workers (median 60, among 30 persons). An HPLC method was developed for the analysis of (32)P-postlabelled 1-NP-DNA-adducts, and was applied to a sub-sample of 20 workers. No significant differences between surface and underground workers were found in this sub-sample with respect to the minor, unidentified adducts that had similar chromatographic properties to 1-NP adducts, and smoking did not have any effect on adduct levels. No significant effects of the genotypes of GSTM1, GSTP1 and GSTT1 on DNA-adducts and on DNA damage as measured by the Comet assay were found in the total study group. The study confirms an increased level of DNA damage in workers exposed to exhaust from truck-driving in the mine. However, the results of the environmental and biological monitoring of 1-NP did not correlate, suggesting that inhalation exposure to diesel exhaust is not reflected by an increase in 1-NP-DNA-adduct levels and/or that factors other than occupational exposure to diesel exhaust are primary determinants of these DNA-adduct levels.

Adult↗
PubMed2004

Delta-aminolevulinic acid dehydratase (ALAD) polymorphism and susceptibility of workers exposed to inorganic lead and its effects on neurobehavioral functions.

We carried out a cross-sectional study on a group of male workers to determine the frequency of delta-aminolevulinic acid dehydratase (ALAD) polymorphisms among Chinese, Malays and Indians workers who were exposed to low to medium levels of inorganic lead. Also, the association between ALAD1 and ALAD2 genotypes and neurobehavioral functions among these workers were investigated. A total of 120 male workers were studied. Blood and urine were collected for each worker to determine the ALAD genotypes, blood lead levels, ALAD, and urinary delta-aminolevulinic acid (ALAU). ALAD1-1 was the predominant genotype for all three ethnic groups while ALAD2-2 was the rarest. The distribution of ALAD1-2 was higher among Malays (16.7%) and Indians (14.3%), compared to Chinese (3.6%). Selected tests from the World Health Organization Neurobehavioral Core Test Battery (WHO-NCTB) were used. Although workers in the ALAD1-1 and ALAD1-2/2-2 groups had comparable blood lead levels, the 106 workers with ALAD1-1 genotypes have significantly higher urinary ALA and significantly poorer neurobehavioral scores involving motor dexterity compared with those who have ALAD1-2/2-2 genotypes (13 workers). It is postulated that the ALAD2 allele may exert protective measures against the neurotoxic effects of lead. Further study involving a larger cohort of workers with the ALAD2 allele would be needed to confirm this hypothesis.

Adult↗
PubMed2005

Evaluation of immuno- and reproductive toxicities and association between immunotoxicological and genotoxicological parameters in waste incineration workers.

In this study, we investigated immunotoxicity levels of 2,3,7,8-tetrachlorodibenzo-p-dioxin in 31 waste incineration workers and in 84 control subjects, and evaluated the association between immunological and genotoxicological parameters. DNA damage in mononuclear and polynuclear lymphocytes, and the level of the urinary metabolites, 1-OHP and 2-naphthol, were evaluated in both waste incineration workers and control subjects. Significant differences were detected in these values between exposed and control groups. Number of sperms was lower in the waste incineration workers than in the control subjects, as was the percentage of motile sperms, but a significant difference existed only in the number of sperms (p=0.05). DNA damage in the spermatozoa of waste incineration workers and control subjects measured 1.40+/-0.08 and 1.26+/-0.03, respectively (p=0.001). Specific surface antigens of peripheral lymphocytes, namely, CD3, CD4, CD8, CD19, and CD69 were used to measure immune status in waste incineration workers and control subjects. There was no significant difference in T- and B-cell profiles showed between waste incineration workers and control subjects (p=0.684 and 0.157). In addition, the ratio of T helper cells to T cytotoxic cells was also not remarkably different between groups (p=0.174). However, T-cell activation was found to be significantly higher in the waste incineration workers than in the control subjects (p=0.001), although B-cell activation did not exhibit this trend. The levels of two cytokines (IL-4 an INF-gamma) and four immunoglobulins (IgA, IgE, IgG, and IgM) were also measured in the experimental population. All immunoglobulin types were found in lower amounts in the waste incineration workers, but this diaparity was not significant one. In addition, the levels of two cytokines, IL-4 and INF-gamma, were also found to be lower in the waste incineration workers than in the control subjects, and only in IL-4 was a significant difference determined to exist.

Adult↗
PubMed2005

Bladder cancer screening and monitoring of 4,4'-methylenebis(2-chloroaniline) exposure among workers in Taiwan.

OBJECTIVES: Transitional cell carcinoma of the urinary bladder is associated with occupational exposure to 4,4'-methylenebis(2-chloroaniline) (MBOCA). A program to monitor MBOCA levels in the work environment and to screen for bladder cancer was performed at four MBOCA manufacturing factories. METHODS: The U.S. Occupational Safety and Health Administration analytic method No. 24 was adopted in this study to measure air MBOCA concentrations. A total of 70 MBOCA-exposed workers and another 92 nonexposed workers were recruited for screening. Urine occult blood tests, urine cytology, tests for the urine tumor marker nuclear matrix protein, and abdominal ultrasonography were performed in all patients. Intravenous urography and cystoscopy were used to confirm the presence of bladder cancer. RESULTS: The air concentration of MBOCA was greatest in the purification area (0.23 to 0.41 mg/m3), followed by the washing area (less than 0.02 to 0.08 mg/m3) and neutralization area (less than 0.05 to 0.06 mg/m3). This study identified a current worker with proved bladder cancer. In addition, we also identified 1 worker with suspected malignant cells on urine cytology and 1 worker with atypical cytology combined with gross hematuria. Although the prevalence of atypical urinary cells and the nuclear matrix protein 22 tumor marker was not significantly different between the MBOCA-exposed workers and nonexposed workers as a whole or when grouped by sex, the prevalence of positive occult blood was marginally significantly (P = 0.055) greater in male exposed workers (18%) than in male nonexposed workers (7%). CONCLUSIONS: The findings of this study support the conclusions from other studies that MBOCA is potentially carcinogenic to humans. Control measures are needed to prevent overexposure from inhalation and skin absorption.

Adult↗
PubMed2003

The relationship between worker satisfaction and productivity in a repetitive industrial task.

The objective of this investigation was to determine the manner by which production standards or goals, performance or production feedback and monetary or wage incentive affected or moderated the relationship between worker satisfaction and productivity in a repetitive production task in a fishing industry. The industrial study was conducted to measure worker satisfaction and productivity under various experimental conditions involving production standards, performance feedback and monetary incentive. Only the participative standard and performance feedback condition affected the worker satisfaction-productivity relationship significantly for the fish-trimming task. The positive correlation coefficient (0.87) for this condition was found to be highly significant. This has an important implication for setting a strategy for achieving higher worker satisfaction and productivity in such an industry. Production standards with feedback generally improved worker satisfaction and productivity. Monetary incentive further improved worker performance but added no incremental satisfaction gain. The incorporation of production standards, performance feedback and monetary incentive affected worker satisfaction and productivity differently and this had an effect on the worker satisfaction-productivity relationship. In an earlier laboratory study, no significant worker satisfaction-productivity relationship was found when subjects (college students) were provided with similar experimental conditions.

Analysis of Variance↗
PubMed2001

Markers for carcinogenicity among butadiene-polymer workers in China.

We examined a spectrum of genotoxic and other outcomes in 41 butadiene-polymer production workers and 38 nonexposed controls, in China, to explore the role of butadiene in human carcinogenesis. Among butadiene-exposed workers, median air exposure was 2 ppm (6-h TWA), due largely to intermittent high-level exposures. Compared to unexposed subjects, butadiene-exposed workers had greater levels of hemoglobin N-(2,3,4-trihydroxybutyl)valine (THBVal) adducts (P<0.0001), and adduct levels tended to correlate, among butadiene-exposed workers, with air measures (P=0.03). Butadiene-exposed workers did not differ, however, from unexposed workers with respect to frequency of uninduced or diepoxybutane-induced sister chromatid exchanges, aneuploidy as measured by fluorescence in situ hybridization of chromosomes 1, 7, 8 and 12, glycophorin A variants or lymphocyte hprt somatic mutation. Also among the exposed, greater THBVal levels were not associated with increases in uninduced sister chromatid exchanges, aneuploidy, glycophorin A, or hprt mutations. Butadiene-exposed workers had greater lymphocyte (P=0.002) and platelet counts (P=0.07) and lymphocytes as a percent of white blood cells were moderately correlated with greater THBVal levels (Spearman's rho=0.32, P=0.07). Among butadiene-exposed workers, several serum cytokines correlated with THBVal adduct levels. Overall, the study demonstrated exposure to butadiene in these workers, by a variety of short-term and long-term measures, but did not show specific genotoxic effects, at the chromosomal or gene levels, related to that exposure.

Air Pollutants, Occupational↗