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PubMed1991

Effects of diurnal and seasonal sleep deficiency on work effort and fatigue of shift workers.

This study was designed to assess and compare the quantity and quality of sleep of morning, afternoon, and night shift workers during the winter and summer seasons, and to evaluate the effects of sleep deficiency on the work effort and fatigue of the workers. The subjects studied consisted of a sample of 150 textile workers, working on a monthly rotating 3-shift system: morning shift (06.00-11.00 and 14.00-17.00) afternoon shift (11.00-14.00 and 17.00-22.00), and night shift (22.00-06.00). Information concerning quantity and quality of sleep were registered daily over a week for every subject. The Ratings of Perceived Effort scale and the Feeling and Symptoms of Fatigue scale were used to collect information about feeling of effort and fatigue of the subjects. The results showed that the duration of sleep length is longest in the afternoon and shortest in the night shift both during summer and winter. The amount of sleep is shorter during summer during all three shifts. The workers spent more effort and felt more fatigued during summer than winter. The shift workers, particularly of the tropical region, like Bangladesh, seem to be worst affected in terms of quantity and quality of sleep, health and well-being due to extremely high temperature (30-45 degrees Celsius) during summer than winter (5-25 degrees Celsius). The workers think that the problems of shift work could be minimized by improving the quality of working and living conditions, reducing cycle of rotation, shortening working day and closing night shift during peak summer.

Adult↗
PubMed1993

Urine, serum and hair monitoring of hydrofluoric acid workers.

To define the relationship between fluoride (F) concentration in the serum, urine and hair of workers and the concentration of hydrofluoric acid (HF) in the work environment, pre- and postshift serum and urine samples of 142 HF exposed workers and 237 unexposed workers were examined. Hair specimens were also collected for the determination of F. To determine whether external contamination influences hair analysis, the control hair samples were kept in the work environment for one week. The pre-exposure levels in serum and urinary F in HF workers were higher (P < 0.01) than the control values. This suggests that F excretion from the body continues for at least 12 hours. The postshift serum and urinary F concentrations of these workers were significantly higher (P < 0.01) than the preshift concentrations. The levels of F in the hair of HF workers were also higher than in the control subjects. The concentrations of F in postshift serum and urine, and hair were in good correlation to each other. There was a linear relationship between mean serum and urinary F concentrations and HF concentration in the workplace. A mean F concentration of 82.3 micrograms/l in serum and 4 mg/l in urine with a lower fiducial limit (95%, P = 0.05) of 57.9 micrograms/l in serum and 2 mg in urine were estimated to correspond to an atmospheric HF concentration of 3 ppm, which is the maximum allowable concentration recommended by Japan Association of Industrial Health and also the threshold limit value suggested by American Conference of Governmental Industrial Hygienists.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1993

Assessment of exposure to chloramphenicol and azathioprine among workers in a South African pharmaceutical plant.

There have been very few published studies that have evaluated exposure to myelotoxic drugs among production workers in pharmaceutical plants. Previous studies have focussed mainly on nurses and evaluated exposure to cytotoxic drugs using urine mutagenicity as a marker of exposure. The aim of this study was to evaluate the exposure of workers involved in the production of chloramphenicol and azathioprine. Exposure was evaluated utilising biological monitoring, biological effect monitoring and environmental monitoring. Biological monitoring included plasma chloramphenicol levels, plasma 6-mercaptopurine and urine 6-thiouric acid levels. These were analysed using high performance liquid chromatography. Myelotoxic effect was assessed by measuring the haematological indices of bone marrow function. The exposed 17 workers were compared to matched controls of equal numbers. Neither substance could be detected in serum nor urine by the analytical methods employed. However, haematological indices demonstrated a significantly decreased mean reticulocyte and neutrophil count in the azathioprine exposed group. Industrial hygiene measurements demonstrated contamination of the air inside the airhood of exposed workers. In conclusion, it is evident that workers involved in the production of both these drugs are at risk of developing adverse health effects. Furthermore, more sensitive analytical methods need to be developed to evaluate absorption of myelotoxic chemicals among occupationally exposed workers.

Adult↗
PubMed1993

Urinary metabolite levels and symptoms in Filipino workers using organic solvents.

To compare symptoms with urinary metabolite levels, 900 workers from 7 organic solvent-using industries were studied. Urinary metabolites were determined using a high performance liquid chromatograph. Urinary hippuric acid concentrations exceeding the reference value (2.5 g/g creatinine) were found in 78 (8.7%) workers. However, only 3 (0.3%) and 1 (0.1%) of the participants exceeded the reference value for mandelic (0.8 g/g creatinine) and total methylhippuric acid (1.5 g/g creatinine), respectively. The sum of the values of the ratio of measured urinary metabolite concentration to the corresponding ACGIH's biological exposure indices (BEI) [(HA/BEI of HA + MHA/BEI of MHA + MA/BEI of MA)] exceeded 1.0 in 166 (18.4%) workers. Majority of them were from the footwear manufacturing industry (63/129 or 49.2%). Questionnaire interviews were also administered to determine the prevalence of symptoms while at work (acute symptoms) or within the past 6 months (chronic symptoms). Urinary metabolite levels of individual and mixed solvents were compared with the symptoms of all workers. Analysis using Spearman's rank correlation showed in workers whose urinary hippuric acid exceeded 3.75 g/g creatine (1.5 x BEI), significant correlation between their hippuric acid levels and subjective complaints. Workers whose sum of the values of the ratio of measured urinary metabolite concentration to corresponding BEI exceeded 1.5 were selected and comparing this level with their symptoms, significant correlation was also noted in some complaints.

Biomarkers↗
PubMed1981

Studies on osmotic fragility of red blood cells determined with a coil planet centrifuge for workers occupationally exposed to lead.

In order to clarify the relationship between lead exposure level and osmotic fragility of red blood cells determined by the coil planet centrifuge method, several clinical laboratory examinations were performed on 27 male workers employed in a scrap lead refining factory using as controls 40 male workers employed in railway construction. The examinations included measurement of red blood cell and reticulocyte counts, hematocrit, MCV, blood and urine lead concentrations, urine coproporphyrin, and urine delta-aminolevulinic acid. The results were: 1. Osmotic fragility of red blood cells was lower in lead workers at all three hemolytic points compared with the controls. Significant difference was observed in hemolysis of the maximum point (P less than 0.05). 2. The red blood cell and reticulocyte counts, hematocrit value and MCV of the lead workers were not significantly different from those of the controls. Values for blood and urine lead, coproporphyrin, and delta-aminolevulinic acid of the lead workers were much higher than those of the controls (P less than 0.01). 3. In lead workers, close relationships between the osmotic fragility and these laboratory findings were observed: blood lead, r = -0.572, P less than 0.01; coproporphyrin, r = -0.608, P less than 0.01; delta-aminolevulinic acid, r = -0.559, P less than 0.01; urine lead, r = -0.453, P less than 0.05.

Adult↗
PubMed1988

Leukocytosis and low serum IgA in workers exposed to the epoxy compound, t-methyl-3-phenylglycidate.

Forty-nine out of 54 male workers engaged in the production of an epoxy compound, t-methyl-3-phenylglycidate, showed skin symptoms in varying degrees that may be due to the skin-irritative effect of the compound. The exposed workers were also shown to have subjective symptoms which may be related to the irritative property of the compound on surface tissue. Laboratory examinations on the blood obtained from the exposed workers showed significantly higher values of leukocyte concentration as compared with the non-exposed controls. This was chiefly caused by the increase of neutrophilic granulocytes and T-cell lymphocytes. Serum IgA levels of the exposed workers were shown to be significantly lower than those of the control group. Hemoglobin concentration, hematocrit value and red cell count of the exposed workers remained at the same level as those of the control subjects. Liver or kidney damage was not found in biochemical analyses on the sera of exposed workers.

Adult↗
PubMed1982

Comparison of renal function and psychomotor performance in workers exposed to elemental mercury.

Renal function and psychomotor performance (eye-hand coordination, arm-hand steadiness) of a group of 43 workers exposed to mercury vapor were examined. Their mean age an average duration of exposure to mercury were 38 and 5 years, respectively. The results were compared with those in a matched group of 47 control workers. Increased proteinuria and albuminuria were found slightly more prevalent in the Hg-exposed group than in the control workers. These results are in agreement with those found during a previous study carrier out in another group of workers also exposed to elemental mercury (Buchet et al. 1980). The scores of the psychomotor tests were less satisfactory in the Hg workers than in the control workers, the arm-hand steadiness test being more discriminative than the eye-hand coordination test. Preclinical changes in psychomotor function can be detected independently of the presence of signs of renal dysfunction. No clear-cut relationships were found between the prevalence of abnormal psychomotor scores and the level of mercury in blood (HgB) or in urine (HgU). Increased prevalences of abnormal psychomotor scores seem however to occur for HgB between 1 and 2 micrograms/100 and for HgU between 50 and 100 micrograms/g creatinine. Therefore, a biologic threshold limit value of 50 micrograms/g creatinine in proposed for urinary mercury to prevent the development of preclinical effects on the central nervous system. A similar critical HgU level based on renal dysfunction prevalences has been suggested in a previous study.

Adult↗
PubMed1993

Respiratory symptoms and ventilatory capacity in workers in a vegetable pickling and mustard production facility.

A group of 117 women occupationally exposed in a pickling factory were studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. Workers were studied by task which included (1) pickling, (2) mustard making, and (3) packing. Similar prevalences for all respiratory symptoms were seen for the three workers groups, with all groups having significantly higher prevalences of chronic cough (P < 0.05), chest tightness, nasal catarrh, and sinusitis (P < 0.01) than a nonexposed control group from a bottling plant. Prevalences of acute symptoms were greater for pickling than for mustard or packing workers. Measured forced expiratory volume in 1 s and maximum flow rates at 50% and the last 25% of the control vital capacity were in general significantly lower than predicted values for the worker subgroups. Pickling workers exposed for more than 1 year in the industry had greater across-shift reductions for all spirometric parameters tested than those workers exposed for 1 year or less. Our data suggest that extended occupational exposure in the pickling industry results in acute exposure-related respiratory effects and ultimately may lead to the development of chronic respiratory symptoms and changes in baseline lung function.

Acetates↗
PubMed1995

Immunological changes among workers occupationally exposed to styrene.

The functional status of the immune system was investigated in a group of 71 workers exposed to styrene and in 65 control subjects, recruited according to the same selection criteria and comparable as to sex, age, and confounding variables. Air and biological monitoring were used to characterize styrene exposure (median of the main urinary metabolites in the "next-morning" spot samples: 106 mg/g creatinine). Phenotypic analysis of peripheral blood lymphocytes (PBL) by automated flow cytometry revealed a reduced proportion of T lymphocyte subsets (CD3+, CD4+ and CD4+45+), with no changes in CD8+, and a higher proportion of B lymphocytes (CD19+) among styrene-exposed workers. The exposed workers showed a higher proportion of activation markers, namely DR and interleukin-2 receptors (CD25). Immunoglobulin subclasses were comparable in the two groups. An increased prevalence of abnormally low values was apparent for CD2+, CD3+, CD4+, CD4+45+ and CD11b subsets among workers exposed to styrene, whereas CD19+, DR+ and CD25+ showed an increased prevalence of abnormally high values. Natural killer-related phenotypes (CD56+, CD56+16+, and CD56+16-) were more expressed among styrene workers, with average increase of 30%. However, the frequency distribution of the lytic activity of natural killer cells against K-562 target cells was shifted towards lower values in the exposed workers as compared to control subjects. Dose-response relationships between indices of internal dose and prevalence of abnormal values were detectable for T lymphocyte subsets, NK phenotypes, and activation markers. These findings suggest that moderate exposure to styrene is associated with an altered distribution of lymphocyte subsets.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1986

The roles of the group home direct care worker.

An attempt is made to make clear statement concerning the roles of the direct care worker in group home treatment programming. For several reasons these roles have not been adequately defined over time. The roles include descriptions of the direct care worker as therapeutic counselor, as manager, as teacher and as relationship builder. The direct care worker is identified as a generalist, a role on the treatment team that is no less important than the role played by the social worker and the psychologist. In the final analysis the professionalization of the direct care worker will depend upon the development of a national focus which can be translated into real college preparatory curricula; into standards which can be utilized to develop certification procedures, and into a hierarchy of jobs for which the direct care worker is the first step.

Acting Out↗
PubMed1986

High frequency of immune dysfunctions in asbestos workers and in patients with malignant mesothelioma.

We have examined the primary immune responses, the numbers of total T (T11+) cells, T-helper (T4+) cells, T-suppressor (T8+) cells, and natural killer (NK) (Leu7+) cells, in 118 healthy control subjects and compared the data to those obtained from 20 patients with clinically diagnosed malignant mesothelioma and 375 long-term asbestos workers without neoplasia. The absolute numbers of total T (T11+) and T-helper (T4+) cells were normal in asbestos workers without neoplasia but were significantly reduced in patients with mesothelioma. T-suppressor (T8+) cells, on the other hand, remained unchanged in the patients but were significantly elevated among the asbestos workers. This resulted in a marked reduction in T-helper (Th) to T-suppressor (Ts) ratios in mesothelioma patients and in asbestos workers. Seventy percent of the mesothelioma patients (14 of 20) had significantly depressed NK-cell activity which could be augmented but not normalized by coincubation in patients' peripheral blood lymphocytes (PBL) with interferon (IFN). Among the asbestos workers three distinctive subgroups could be identified: heightened (H-NK), normal (N-NK), and low (L-NK) NK activity. The NK activity of the L-NK group could be stimulated but not normalized by coincubation with IFN, a finding closely resembling that in malignant mesothelioma patients. Phenotyping of the circulating NK cells revealed a unique Leu7+ subset in increased numbers with a brightly fluorescent property in stable mesothelioma patients with relatively stable or slowly progressive disease and in more than 30% of the asbestos workers.(ABSTRACT TRUNCATED AT 250 WORDS)

Asbestos↗
PubMed1992

Assessment of therapeutic relationship of community-agency workers.

This article reports on the ratings of the personal and professional characteristics of community-based workers for children and adolescents who had recently been released from a psychiatric inpatient service. The child/adolescent's family members/caregivers and the community workers both responded to the same items of a questionnaire. Families/caregivers rated the community workers with whom they were the most and the least satisfied. Community workers rated themselves in relation to these study children and/or their families. Findings indicate that both family members/caregivers and the community workers themselves saw community workers performing relatively well in the areas of providing information and offering support to families. Likewise, both assessed the service providers as having the greatest deficits in the area of teaching skills for child/adolescent home management. Suggestions for meeting the needs of the families and for ensuring that a system of care for child/adolescents is child-centered and family-focused are discussed.

Adolescent↗
PubMed1995

Internal exposure of waste incineration workers to organic and inorganic substances.

One hundred and twenty-two persons employed in an industrial waste incineration plant were examined with respect to organic and inorganic substances which may be produced during the combustion of different waste. The employees were divided into three groups: persons with contact with the incinerator (WI workers, n = 45), periphery workers (n = 54) and management (n = 23). For the evaluation of internal exposure, the levels of lead, cadmium, mercury, benzene, toluene, ethylbenzene and m-xylene in blood, chromium in the erythrocytes, polychlorinated biphenyls, hexachlorobenzene and pentachlorophenol in plasma, and arsenic, chromium, nickel, vanadium, chlorophenols and hydroxypyrene in urine were determined. The internal exposures of the three groups were tested against each other and were compared with the reference values of the general population. Differences between the groups investigated were tested using the U test according to Wilcoxon, Mann and Whitney (P < 0.05). The biological exposure limits valid in Germany (BAT values) were not exceeded in any cases. Compared with the background levels of the German population, certain parameters were exceeded in several employees. Significantly higher levels of the WI workers in comparison to both periphery workers and management were found for toluene in blood (median: 1.1 vs 0.9 vs 0.6 microgram/l). For the lead and cadmium levels in blood and for the urinary excretion of arsenic, 2,4-dichlorophenol and tetrachlorophenols, statistical differences were found only between WI workers and one of the other groups. However, in all cases the elevations were very small and of interest more from the environmental than from the occupational point of view. It must be stressed that this waste incineration plant is very modern in terms of worker health and safety. At older plants without corresponding health and safety measures, higher internal exposure of the employees to hazardous substances may exist.

Adult↗
PubMed2004

Does the queen win it all? Queen-worker conflict over male production in the bumblebee, Bombus terrestris.

Social insects provide a useful model for studying the evolutionary balance between cooperation and conflict linked to genetic structure. We investigated the outcome of this conflict in the bumblebee, Bombus terrestris, whose annual colony life cycle is characterized by overt competition over male production. We established artificial colonies composed of a queen and unrelated workers by daily exchange of callow workers between colony pairs of distinct genetic make-up. Using microsatellite analysis, this procedure allowed an exact calculation of the proportion of worker-derived males. The development and social behavior of these artificial colonies were similar to those of normal colonies. Despite a high worker reproduction attempt (63.8% of workers had developed ovaries and 38.4% were egg-layers), we found that on average 95% of the males produced during the competition phase (CPh) were queen-derived. However, in four colonies, queen death resulted in a considerable amount of worker-derived male production. The different putative ultimate causes of this efficient control by the queen are discussed, and we suggest a possible scenario of an evolutionary arms race that may occur between these two female castes.

Animals↗
PubMed2006

Winged queens replaced by reproductives smaller than workers in Mystrium ants.

In ants, winged queens that are specialized for independent colony foundation can be replaced by wingless reproductives better adapted for colony fission. We studied this shift in reproductive strategy by comparing two Mystrium species from Madagascar using morphometry, allometry and dissections. Mystrium rogeri has a single dealate queen in each colony with a larger thorax than workers and similar mandibles that allow these queens to hunt during non-claustral foundation. In contrast, Mystrium 'red' lacks winged queens and half of the female adults belong to a wingless 'intermorph' caste smaller and allometrically distinct from the workers. Intermorphs have functional ovaries and spermatheca while those of workers are degenerate. Intermorphs care for brood and a few mate and reproduce making them an all-purpose caste that takes charge of both work and reproduction. However, their mandibles are reduced and inappropriate for hunting centipedes, unlike the workers' mandibles. This together with their small thorax disallow them to perform independent colony foundation, and colonies reproduce by fission. M. rogeri workers have mandibles polymorphic in size and shape, which allow for all tasks from brood care to hunting. In M. 'red', colonial investment in reproduction has shifted from producing expensive winged queens to more numerous helpers. M. 'red' intermorphs are the first case of reproductives smaller than workers in ants and illustrate their potential to diversify their caste system for better colonial economy.

Animals↗
PubMed2002

Susceptibility factors and DNA adducts in peripheral blood mononuclear cells of aluminium smelter workers exposed to polycyclic aromatic hydrocarbons.

Formation of DNA adducts as a result of exposure to polycyclic aromatic hydrocarbons (PAH) was studied in 98 potroom workers from an aluminium smelting plant and in 55 blue-collar workers without occupational PAH exposure. DNA from peripheral blood mononuclear cells (PBMC) was used for quantitation of individual PAH-DNA adducts by 32P-postlabelling/high performance liquid chromatography (HPLC) analysis. Four individual DNA adducts (denoted A, B, C and D) were quantified in 141 of a total of 153 subjects. Genetic polymorphisms for cytochrome P-4501A1 ( CYP1A1), microsomal epoxide hydrolase, N-acetyltransferase 2, glutathione transferases M1, P1 and T1 ( GSTM1, GSTP1 and GSTT1, respectively) and NAD(P)H: quinone oxidoreductase 1 (NQO1) were analysed. For 52 subjects, analysis of mRNA inducibility of CYP1A1 was performed. No statistically significant differences in the levels of total or individual DNA adducts A, C and D were found between potroom workers and control subjects. All potroom workers and the subgroup of potroom workers who reported to never/sometimes use personal respiratory protection ( n=72) were found to have a significantly higher likelihood of having high levels of adduct B than control subjects [odds ratio (OR) =3.4 with 95% confidence interval (CI) of 1.3-9.2, and OR=4.2 with 95% CI 1.6-11.5, respectively]. In the subgroup, levels of adducts A and B were found to be significantly higher among workers with employment time of less than 6 months ( n=5). Also, the levels of the individual DNA adducts were to some extent modified by genetic polymorphisms in CYP1A1, GSTM1, GSTP1 and NQO1 and by CYP1A1 inducibility. In conclusion, levels of adduct B, identified by 32P-postlabelling/HPLC methodology as an indicator of PAH exposure in aluminium production, were modified by the use of respiratory protection, length of employment and genetic polymorphisms.

Aluminum↗
PubMed2002

Relationship between blood lead levels and renal function in lead battery workers.

OBJECTIVES: The aim of this study was to investigate the correlation between blood lead (PbB) levels and renal function indices of blood-urea nitrogen (BUN), serum creatinine (SC) and uric acid (UA) among lead battery workers with exposure to lead. METHODS: A total of 229 workers of both genders from two lead battery factories were recruited in this cross-sectional study. The personal airborne and blood samples were collected on the same day. The airborne lead (PbA) and PbB levels, and individual renal function parameters were measured and statistically analyzed. RESULTS: A positive correlation between PbB levels and individual renal function index of BUN, SC, and UA was found ( P<0.01). The PbB levels and renal function indices showed significant difference between male and female workers. Based on a multiple regression model, an increment of 10 micro g/dl PbB produced an increase of 0.62 mg/dl BUN, after being adjusted for work duration and age, and an increase of 0.085 mg/dl UA, after being adjusted for gender and body weight. Workers with PbB 60 microg/dl showed a positive dose-effect relationship with significant difference in BUN ( P<0.001) and UA ( P<0.05), and the percentage of workers with BUN and UA over the reference value also showed an increasing trend. CONCLUSION: Blood-urea nitrogen and uric acid could be considered as suitable prognostic indicators of renal dysfunction in lead-exposed workers. Our results showed that PbB levels higher than 60 micro g/dl had increasing chances of inducing adverse renal effects.

Adolescent↗
PubMed2002

A neuropsychotoxicological assessment of workers in a sodium azide production plant.

OBJECTIVE: Despite its known toxicity and extensive current industrial use, the occupational neuropsychotoxicology of sodium azide has not yet been investigated. METHOD: Neuropsychological and psychological tests, a symptom self-report questionnaire and haematological and cardiac measurements were gathered from 41 exposed workers and 42 unexposed workers in a chemical production plant yearly for 3 years. RESULTS: The exposed workers presented significantly more acute symptoms of exposure (headache, vertigo, nausea, fatigue, cardiac palpitations, irritated or red eyes) than did the unexposed workers. However, only one chronic symptom was repeatedly and more significantly reported, namely trembling of the hands. No psychological or neuropsychological tests (reaction time, psychomotor, cognitive, chromatopsia, Profile of Mood States) differentiated the two groups. However, acute effects of exposure on plasma creatinine and on systolic pressure were noted. Low creatinine levels in the plasma of exposed workers correlated significantly with impairment of mood on the Profile of Mood States test, but not with any other measure. We recommend that workers exposed to sodium azide be assessed with tremometry, clinically and in a future field study.

Adult↗