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PubMed2000

Are variations in cuticular hydrocarbons of queens and workers a reliable signal of fertility in the ant Harpegnathos saltator?

One of the key features of insect societies is the division of labor in reproduction between one or a few fertile individuals and many sterile nestmates that function as helpers. The behavioral and physiological mechanisms regulating reproduction in ant societies are still not very well understood, especially in species in which all colony members are reproductively totipotent. In the ponerine ant Harpegnathos saltator, queen-worker dimorphism is very limited, and a few mated workers reproduce ("gamergates") once the founding queen becomes senescent. Worker oviposition is regulated by highly directed aggressive interactions among nestmates, who can recognize different levels of ovarian activity. We show that variations in cuticular hydrocarbons (CHC) correlate with oogenesis, both for queens and workers. 13,23-Dimethylheptatriacontane is present in egg-layers, but not in infertile workers and queens. Proportions of other CHCs vary as well, resulting in clear separation of the ants in a multivariate analysis. Egg-layers are characterized by an elongation of the chain length of CHCs. We used solid-phase microextraction to measure CHCs in live ants that were experimentally induced to start producing eggs. Over a period of 118 days, CHC profiles of infertile workers changed completely to that of reproductives. The effect of age can be excluded in this modification. This striking correlation of ovarian activity with CHC variation and its correspondence with the observed recognition behavior exhibited by the workers toward egg-laying nestmates suggests that CHCs serve as a fertility signal in the ant H. saltator, a reliable basis for regulating reproduction.

Animals↗
PubMed2004

Cross-sectional study of cardiovascular effects of carbon disulfide among Chinese workers of a viscose factory.

OBJECTIVE: This cross-sectional study investigates the cardiovascular effects among Chinese workers who were occupationally exposed to carbon disulfide (CS2), and evaluates the protective value of the current Chinese Maximum Allowable Concentration (MAC) of CS2 against cardiovascular effects. METHODS: The measurements of exposure were performed by personal sampling and gas chromatography. The biological monitoring was performed by HPLC. Three hundred and sixty-seven exposed workers and 125 reference workers (never exposed to CS2,) were included in this study. The exposed workers were divided into 2 sub-groups according to their cumulative exposure indices, the cut-off point being at 100 which means 10 years exposure to the Chinese Maximum Allowable Concentration in the workplace (10 mg/m3). All subjects were examined using a self-administered questionnaire including medical and job history, clinical complaints in the previous three months, and underwent a clinical check-up and a 12 lead electrocardiography (ECG) at rest, coded according to the Minnesota code. Blood pressure (BP) was recorded and blood samples were collected for lipid measurements. RESULTS: The personal monitoring showed that the exposures levels (15.47 +/- 2.34 mg/m3) were below the Threshold Limit Value (TLV, 31 mg/m3), and most of the samples analyzed still showed higher values than the Chinese MAC (10 mg/m3). Clinical complaints and abnormal electrocardiograms were not significantly increased in exposed workers. No significant effect of CS2 on blood pressure, cholesterol, HDL and LDL cholesterol or triglycerides was found. Further studies are recommended to elucidate the mechanism of cardiac intoxication after CS2 exposure. CONCLUSION: This study showed that Chinese workers exposed to CS2 did not have more clinical complaints, nor more ECG abnormalities than controls and no adverse effects were found in their lipids at an exposure level below the current TLV. The present results indicate that differences of health effects reported worldwide are possibly due to different exposure levels. They also indicate that the current Chinese MAC (10 mg/m3) sufficiently protects workers against negative cardiovascular effects.

Adolescent↗
PubMed2004

Antioxidant response at early stages and low grades of simple coal worker's pneumoconiosis diagnosed by high resolution computed tomography.

In miners exposed to coal dusts, coal worker's pneumoconiosis (CWP) can occur. The purpose of the present study is to better understand the relations between coal dust exposure and activities of blood plasma antioxidant enzymes, namely, superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), and lipid peroxidation end product malondialdehyde (MDA) concentration in coal workers with early and low grade simple CWP diagnosed by high resolution computed tomography (HRCT). Forty-three coal workers who had profusions of 0/1-2/2 according to ILO 1980 chest X-ray (CXR) classification, 43 coal workers without CWP (control group 1) and 44 healthy subjects (control group 2) who were randomly selected from the population register or recruited from the hospital staff were enrolled. Coal workers were reevaluated by HRCT (Hosoda-Shida classification) due to its higher sensitivity than standard CXR. Then, blood plasma SOD and GSH-Px activities and MDA plasma levels were measured. CWP was found positive in 46 of 89 coal workers by HRCT evaluation. Profusion 0 (P0, CWP not present), profusion 1 (P1, early CWP) and profusion 2 (P2, low grade CWP) were found in 43, 23 and 19 of patients found to have CWP by HRCT, respectively. We had no worker with profusion 3 (P3). Complicated CWP was shown in four of 46 patients and thesecases were excluded as the study was restricted to early and low-grade pneumoconiosis. In respect to the plasma levels of MDA and plasma activities of SOD and GSH-Px, statistically significant differences were found between CWP cases and control groups (p < 0.01, p < 0.01, p < 0.001 respectively). Statistical differences were also obtained for the plasma activities of SOD and GSH-Px and levels of MDA in relation to HRCT profusions (p < 0.05). In conclusion, these findings suggest an oxidative stress due to increased free radicals and reactive oxygen metabolite production in early stages and low grades of simple CWP diagnosed by HRCT.

Adult↗
PubMed2006

Assessment of central auditory processing in a group of workers exposed to solvents.

CONCLUSION: Despite having normal hearing thresholds and speech recognition thresholds, results for central auditory tests were abnormal in a group of workers exposed to solvents. Workers exposed to solvents may have difficulties in everyday listening situations that are not related to a decrement in hearing thresholds. A central auditory processing disorder may underlie these difficulties. OBJECTIVE: To study central auditory processing abilities in a group of workers occupationally exposed to a mix of organic solvents. MATERIALS AND METHODS: Ten workers exposed to a mix of organic solvents and 10 matched non-exposed workers were studied. The test battery comprised pure-tone audiometry, tympanometry, acoustic reflex measurement, acoustic reflex decay, dichotic digit, pitch pattern sequence, masking level difference, filtered speech, random gap detection and hearing-in-noise tests. RESULTS: All the workers presented normal hearing thresholds and no signs of middle ear abnormalities. Workers exposed to solvents had lower results in comparison with the control group and previously reported normative data, in the majority of the tests.

Adolescent↗
PubMedDate not supplied

Risk of hepatitis A virus infection among sewage workers in Israel.

Sewage workers are exposed to a wide range of chemicals and biological agents, including the hepatitis A virus. Inasmuch as Israel is an endemic area for hepatitis A, it is unclear if sewage workers are at increased risk for hepatitis A or which factors contribute to such risk. The authors compared seropositivity of hepatitis A in 100 sewage workers with that in 100 blue-collar worker controls. Hepatitis A seropositivity was highly prevalent, but nonsignificant, in both sewage workers and controls (82% and 91%, respectively). In sewage workers, the major risk for serological positivity was age (odds ratio = 4.5, 95% confidence interval = 1.6, 12.4 for every 10 y). The factors associated negatively with seropositivity were years of education and years of seniority. The authors concluded that exposure to sewage is not a risk factor for hepatitis A infection in Israel, and, therefore, sewage workers do not require special attention in this regard.

Adult↗
PubMedDate not supplied

Urinary 1-hydroxypyrene levels in workers exposed to coke oven emissions at various locations in a coke oven plant.

Polycyclic aromatic hydrocarbons, which are carcinogenic and mutagenic to humans, are primary compounds in coke oven emissions generated by the coking process. The authors examined the relationship between coke oven workers' urinary 1-hydroxypyrene levels and their exposure to polycyclic aromatic hydrocarbons, as determined on the basis of work category and pre- and postshift effects in a steel plant in Taiwan. Eighty-eight coke oven workers constituted the exposed group, and 61 office workers in a steel plant located 1.5 km from the coke plant constituted the control group. The benzene-soluble fraction in personal air samples, and 1-hydroxypyrene in urine samples, were measured for 3 consecutive days. The 3-day urinary 1-hydroxypyrene sampling results for topside workers (i.e., those most heavily exposed to emissions) in the coke oven group, and for the control group, as determined from postshift geometric means, were 23.8 microg/gm creatinine and 0.3 microg/gm creatinine, respectively. These values increased to 13.4 and 0.1 microg/gm creatinine, respectively, after an 8-hr work period. The major source of polycyclic aromatic hydrocarbons for the exposed group was occupational; therefore, the closer workers were to the coke oven, the greater their exposure, and, consequently, the greater their metabolite level. Urinary 1-hydroxypyrene levels of the exposed group were 80 times higher than those of the control group. Smoking had no significant effect on the excretion of urinary 1-hydroxypyrene. 1-hydroxypyrene levels in the workers' urine during an 8-day period was cumulative (half-life = 18.6 hr). The authors concluded that it would be desirable to switch highly exposed workers to a low-exposure work area, after a period of rest. In addition, urinary 1-hydroxypyrene was a confirmed, useful biological indicator for exposure to polycyclic aromatic hydrocarbons.

Air Pollutants, Occupational↗
PubMedDate not supplied

Epidemiologic health study of workers in an aluminum smelter in Kitimat, B.C. II. Effects on musculoskeletal and other systems.

A health study was carried out on 2066 workers in an aluminum smelter in Kitimat, British Columbia to study the effects of exposure to fluoride and other air contaminants encountered on the potlines on the musculoskeletal system, hemopoietic tissue, liver, and renal function. Three hundred seventy-two railway repair workers from Squamish, British Columbia served as an "external" control group. Examination of the spine and sacroiliac joints and pelvic X-ray were conducted on long-term potline workers and a number of "internal" control workers in the smelter not exposed to any air contaminants. Urinary fluoride measurements and personal sampling for airborne fluoride were also carried out. Blood samples were collected for routine blood count and liver and renal function test. Definite cases of skeletal fluorosis were not found in any potroom workers. Some of the changes of early skeletal fluorosis described on pelvic X-rays, e.g., increased density, calcification of ligaments, and periosteal changes, were found in a few workers who were employed on the potlines for more than 10 yr. There was, however, poor agreement in the findings of the two radiologists who read the films. The entity "musculoskeletal fluorosis" does not exist in this smelter where the potroom workers were exposed to total fluoride levels below the currently accepted threshold limit value of 2.5 mg/m3. No ill effects on the hematopoietic tissue or liver and renal function were found.

Air Pollutants↗
PubMedDate not supplied

Byssinosis: serum immunoglobulin and complement concentrations in cotton mill workers.

In two separate studies (labeled A and B), concentrations of IgC, IgM, IgA, C3, and C4 were determined in the sera of byssinotic and non-byssinotic cotton mill workers. In study A, sera were collected on Monday morning and Monday afternoon and Friday afternoon in order to ascertain if the waning byssinotic response from Monday to Friday correlates with changes in serum immunoglobulin and complement concentrations. In study B, sera was collected on Monday morning and afternoon and was performed primarily to evaluate history of atopy and smoking as complicating factors in byssinosis. In study A, the concentrations of all immunoproteins were found to decrease from Monday morning to to Friday afternoon in all textile workers, and in study B only C3 concentration decreased morning to afternoon. There was, however, no difference between the immunoprotein changes for byssinotic workers when compared to non-byssinotic workers in either study. Due to the fact that hypersensitivity pneumonitis causes a decrease in immunoprotein concentrations in affected workers while no decreases are noticed in normal workers, our data do not support an immune complex etiology for byssinosis. In addition, decreased serum C3 concentrations observed in this study could be caused by complement activation; however, there was no difference in complement levels between byssinotic and non-byssinotic textile workers. Therefore, these data neither support nor eliminate the involvement of antibody-independent complement activation in the pathogenesis of byssinosis.

Byssinosis↗
PubMedDate not supplied

Respiratory findings in spice factory workers.

The respiratory consequences of working in the spice industry were studied in 92 female spice factory workers (mean age, 36 yr; mean exposure, 12 yr). A control group of 104 female workers employed in a nondusty industry was also studied. The prevalence of chronic respiratory symptoms was significantly higher in the exposed than in the control group. In particular, the prevalence of dyspnea (57.6%), chronic cough (22.8%), chronic phlegm and chronic bronchitis (19.6%), nasal catarrh (37.0%), and sinusitis (22.2%) was high when compared to controls (p less than .01). Among spice factory workers, a high prevalence of acute symptoms during the workshift was recorded. Acute reductions in lung function were statistically significant over the workshift for forced vital capacity (FVC), -2.0%; forced expiratory volume in one second (FEV1.0), -3.0%; and for maximum expiratory flow rates at 50% (FEF50), -8.3% and at 25% (FEF25), -15.2% measured on maximum expiratory flow-volume (MEFV) curves. No difference was found in across-shift ventilatory function in workers with or without chronic respiratory symptoms, except for FEF25 (with symptoms, 16.7%; without symptoms, 9.6%). Preshift administration of 40 mg of disodium cromoglycate (DSC) inhaled 15 min before the workshift significantly diminished acute reductions in FEF50 and FEF25 in exposed workers. Monday preshift FEF50 and FEF25 in exposed workers were significantly lower than in control workers (p less than .01), which suggests an early irreversible component to this illness.

Adolescent↗
PubMedDate not supplied

Increased risk of esophageal cancer among workers exposed to combustion products.

Alcohol and tobacco habits have been identified as strong risk factors for esophageal cancer. Increased risks of esophageal cancer have also been reported to be associated with occupational exposure to asbestos and various metals, among vulcanization workers, asphalt workers, and workers in the petrochemical industry. Mortality and cancer incidence were investigated in a series of studies of workers exposed to combustion by-products, i.e., chimney sweeps, waste incinerator workers, gas workers, and bus garage workers exposed to diesel exhausts. The SMRs for esophageal cancer ranged from 150-386 in these cohorts, and a combined SMR of 289 (95% C.I. 174-452) was obtained. Available data on smoking habits and indirect indicators of alcohol consumption show that the excess cannot be attributed solely to these factors. It seems likely that occupational exposure to combustion products is associated with an increased risk of esophageal cancer.

Alcohol Drinking↗
PubMed1991

Occupational musculoskeletal disorders in the neck and upper limbs of forestry workers exposed to hand-arm vibration.

An epidemiologic and clinical study of neck and upper limb musculoskeletal disorders was carried out on 65 vibration-exposed forestry operators using chain-saws and 31 comparable control subjects (maintenance workers) performing manual activity and not exposed to vibration. Upper limb function was evaluated by measuring finger and wrist circumference size, maximal hand grip strength and range of motion manoeuvres in both the controls and the exposed workers. Vibration from two chain-saws was measured, and vibration exposure for each forestry worker was assessed in terms of 4 h energy-equivalent frequency-weighted acceleration according to ISO 5349. Job analysis indicated a slight excess risk of upper extremity cumulative trauma disorders (CTDs) in the forestry operators compared with the control workers. After adjustment for age and body constitution, significantly higher prevalence rates of persistent upper limb pain, muscle-tendon syndromes and carpal tunnel syndrome were observed among the forestry workers than among the controls. In the forestry operators, the occurrence of upper limb musculoskeletal disorders increased with increasing vibration exposure. Upper limb function was found to be impaired in the forestry workers compared with the controls. Vibration exposure was significantly related to increased finger circumference size, diminished muscle force and reduced joint function. Even though it is difficult to establish the relative importance of vibration and ergonomic factors in the aetiology of CTDs, nevertheless the results of this study indicate that musculoskeletal impairment to the upper limbs was more severe in the forestry operators than in the controls who did solely manual work. This finding and the observed dose-effect relationships suggest that vibration stress is an important contributor to the development of musculoskeletal disorders in workers using hand-held vibrating tools.

Adult↗
PubMed2006

Psychosocial work characteristics predicting daytime sleepiness in day and shift workers.

Characteristics of work organization other than working time arrangements may contribute importantly to daytime sleepiness. The present study was designed to identify the psychosocial factors at work that predict daytime sleepiness in a sample of day and shift workers. Participants working at a pulp and chemical factory completed an annual questionnaire regarding psychosocial factors at work using the U.S. National Institute for Occupational Safety and Health Generic Job Stress Questionnaire (i.e., quantitative workload, variance in workload, job control, support from supervisor, coworkers, or family/friends, job satisfaction, and depressive symptoms), as well as daytime sleepiness (through the Epworth Sleepiness Scale [ESS]) and sleep disturbances for three years starting in 2002 (response rates, 94.6-99.0%). The present analysis included 55 day workers (11 women) and 57 shift workers (all men) who participated in all three years of the study, worked under the same work schedule throughout the study period, and had no missing data on any of the daytime sleep items. A repeated-measures analysis of covariance (ANCOVA) was used to test the effects of work schedule (day vs. shift work) and psychosocial factors at work in 2002 on the ESS scores in subsequent years, with sleep duration, insomnia symptoms, chronic diseases, and sleepiness levels at baseline as covariates. Given significant and near-significant interactions of work schedules with psychosocial factor or study year, the ANCOVA, with the factors of psychosocial work characteristics and study year, was performed by type of work schedule. The results indicated a significant main effect of psychosocial work characteristics (p = 0.010, partial eng2 = 0.14) and an almost significant main effect of study year (p = 0.067, partial eng2 = 0.06) and interaction between psychosocial work characteristics and study year (p = 0.085, partial eng2 = 0.06) for variance in workload among the day work group. The day workers reporting high variance in workload in 2002 exhibited significantly higher ESS scores in 2003 and 2004 than did those reporting low variance in workload. The ANCOVA for the shift work group showed a main effect of psychosocial work characteristics for job satisfaction (p = 0.026, partial eng2 = 0.10) and depressive symptoms (p = 0.094, partial eng2 = 0.06) with the interaction between psychosocial work characteristics and study year for job satisfaction (p = 0.172, partial eng2 = 0.04) and depressive symptoms (p = 0.035, partial eng2 = 0.07). The shift workers with low job satisfaction and high symptoms of depression in 2002 showed significantly greater ESS scores in 2003 and/or 2004 than did those with opposite characteristics. These results may suggest a potential predictive value of variance in workload for day workers as well as job satisfaction and depressive symptoms for shift workers with respect to daytime sleepiness. The present findings may imply that redesigning these aspects of work environment would be of help in managing daytime sleepiness.

Adult↗
PubMed2001

Effects of peak levels and number of impulses to hearing among forge hammering workers.

The purpose of the study was to (1) compare measured and estimated hearing loss among forge hammering workers by applying models for risk assessment based on measurements of impulse noise, and (2) model the hazardous effects of impulse noise on hearing. Noise exposure and hearing loss among forge hammering workers were studied at two forge workshops of an automobile company, where the equivalent sound pressure levels (104 and 105 dB) were the same, but the peak levels and degree of impulsiveness were significantly different. The hearing threshold levels of selected groups of workers (97 and 235 workers) were determined. Comparison between the measured and expected hearing losses defined according to the ISO standard revealed 2 dB difference in excessive hearing loss (1 dB and 3 dB for the workers of workshop 1 and 2, respectively). The excessive hearing loss equals an increase of 3.5 years of exposure. The hearing loss of workers exposed to low impulsive noise could be predicted well using ISO 1999-1990. The hearing loss of workers exposed to high impulsive noise correlated significantly with the peak levels and the number of impulses in combination.

Adult↗
PubMed2003

Evaluation of hypersensitivity pneumonitis among workers exposed to metal removal fluids.

Hypersensitivity pneumonitis (HP) was identified among employees in an automobile parts manufacturing facility. Mycobacteria immunogenum (MI) was identified as a metal removal fluid (MRF) contaminant at this facility and had been identified as a contaminant in other facilities where HP had occurred. We therefore questioned whether measurement of MI-specific cell-mediated immunity would be associated with HP in this facility. We also questioned whether measures of cell-mediated immunity would be more informative about the presence of HP than evaluation of serum anti-MI antibody levels. Workers were categorized for exposure and disease status by questionnaire and review of medical records. Cell-mediated immunity to MI was assessed by measuring in vitro secretion of cytokines (interleukin 8, tumor necrosis factor alpha, and interferon-gamma) from peripheral blood mononuclear cells or anticoagulated whole blood induced by culture with MI antigen. Serum antibodies against MI were also measured. Six study participants met our survey definition for HP and 48 did not. As has been reported for various agents causing HP, serum antibody levels against MI were increased in both exposed workers and workers with HP. Serum antibodies did not distinguish between the two. When expressed as a percentage of secretion induced by lipopolysaccharide, MI induced a significant increase in interleukin-8 secretion in exposed participants' whole blood cultures. There were trends for increased MI-induced secretion of interferon-gamma by peripheral blood mononuclear cells from both exposed workers and workers with HP. However, these trends did not attain statistical significance. Thus, several measures of immunity to MI distinguished between exposed and unexposed workers but not between workers with and without HP. These evaluations of cell-mediated immunity were not more informative than measurement of serum antibodies. As was done at this facility, institution of a comprehensive safety and health plan for MRF is necessary to eliminate (or minimize) health effects related to occupational exposures in the machining environment.

Adult↗
PubMedDate not supplied

Associations between XRCC1 and ERCC2 polymorphisms and DNA damage in peripheral blood lymphocyte among coke oven workers.

A wide variety of base damages and single-strand breaks formed by reactive oxygen species during metabolic activation of polycyclic aromatic hydrocarbons (PAHs) have been recognized to be involved in PAH carcinogenesis. In this study, alkaline comet assay was used to detect the DNA damage in peripheral blood lymphocytes among 143 coke-oven workers and 50 non-coke-oven workers, and the effects of genetic polymorphisms of XRCC1 and ERCC2 genes on DNA damage were evaluated. The olive tail moment was significantly higher in coke-oven workers than in non-coke-oven workers (2.6, 95% CI=2.1-3.3 versus 1.0, 95% CI=0.8-1.2, p<0.01), and significant correlation between ln-transformed urinary 1-OHP and ln-transformed olive tail moment was found in total population (n=193, Pearson's r=0.393, p<0.001) and in coke-oven workers (n=143, Pearson's r=0.224, p=0.007). The olive tail moment was significantly higher in coke-oven workers with GA genotype of G27466A polymorphism of XRCC1 than those with GG genotype (4.6, 95% CI=2.5-8.7 versus 2.4, 95% CI=1.9-2.9, p<0.01 with adjustment for covariates). No significant associations between C26304T, G28152A and G36189A polymorphisms of XRCC1 and G23591A and A35931C polymorphisms of ERCC2 and olive tail moment were found in both groups. The study showed that the alkaline comet assay is a suitable biomarker in the detection of DNA damage among coke-oven workers and it suggested that the A allele of G27466A polymorphism of XRCC1 may be associated with decreased DNA repair capacity toward PAH-induced base damage and strand breaks.

Adult↗
PubMed2005

Estimation of burden of lead for offspring of female lead workers: a quality-adjusted life year (QALY) assessment.

This study demonstrates an empirical example that uses quality-adjusted life year (QALY) as a common metric for occupational health assessment to measure the utility loss of potential lead-exposed children delivered by female lead-battery-exposed workers. A set of nationwide health examination data was used for 1726 lead workers. Among them, there were 649 female workers. The numbers of offspring from female lead workers were estimated by multiplying the age-specific fertility rate (ASFR) by the number of workers in each age stratum. The quality of life assessment for these offspring was assumed impaired by increased absorption of lead using a measure of utility for quality of life that was adapted from Rosser's index of health-related quality of life. The total utility loss was calculated by summing up the loss of QALY for these expected offspring. Dose-response and exposure assessments were based on their mothers' blood lead levels. It was estimated that more than 38 babies were delivered in 1 yr. There would be 19 babies born with blood lead levels over 30 microg/dl, and about 17 babies with blood lead between 10 and 29 microg/dl. The expected utility loss of the babies was estimated to be about 216 QALY, of which 51.6 QALY was attributed to the babies with moderate blood lead level, while that of high blood lead was 164.4 QALY. An effective industrial hygiene program to reduce blood lead to 5, 10, and 15 microg/dl in female lead-exposed workers would decrease the utility loss to 169.5, 126.8, and 92.3 QALY, respectively, in the offspring. An alternative policy of raising the age of female workers by 5 or 10 yr before employment would also reduce the loss to 174.6 or 107.4 QALY. Data suggest that an effective industrial hygiene program should be implemented, and the use of QALY as a common metric for comparative assessment of occupational health policy may be feasible.

Adult↗
PubMed1988

Health status of a group of sewage treatment workers in Toronto, Canada.

Fifty randomly selected workers in a sewage treatment plant using a heat treatment method for processing sewage sludge in Toronto, Canada were assessed. This investigation revealed that many workers reported "influenza-like" symptoms, cough, sputum production, wheezing, sore throat and skin complaints. The workers tended to have somewhat reduced lung function. Workers in the area of the plant where boiled sewage sludge was dried frequently reported an intermittent, acute illness characterized by cough, fever and sore throat. Workers in the area of the plant where the dried sludge was incinerated tended to have reduced lung function. The basis for the possible health effects demonstrated has not been established, and further investigation is suggested. The mean level of polychlorinated biphenyls (PCBs) detected in the workers' serum was 6 +/- 5 ppb. The PCB levels could not be related to symptoms or clinical findings in the workers studied.

Acute Disease↗
PubMedDate not supplied

Quantitative exposure assessment for shipyard workers exposed to hand-transmitted vibration from a variety of vibration tools.

The quantitative exposure to vibration for shipyard workers who have used several kinds of vibratory tools was studied. The dose-response relationship between lifetime exposure dose and hand-arm vibration syndrome also was studied. The study included 344 workers who were exposed to vibration in one shipyard and 53 unexposed workers in the same company. Vibration measurements were made on several vibratory tools according to the international standard, ISO 5349. The actual exposure times for the vibratory tools were measured. Questionnaires for demographics, exposure to vibration, and confounding factors were completed. A lifetime vibration dose was calculated for each worker using job categories, usage pattern of vibratory tools, and the measured vibration acceleration magnitude. Each worker was asked about vascular and neurological symptoms, and symptoms were classified according to the Stockholm workshop scale. The prevalence of vascular and sensorineural symptoms for workers exposed to vibration was 22.7 and 78.2%, which were significantly higher than 0 and 34.0% obtained in the nonexposed workers, respectively. The prevalence and severity of the hand-arm vibration syndrome was increased with an increased lifetime vibration dose. The lifetime vibration dose showed a significant association with both vascular and sensorineural symptoms. In conclusion, the lifetime vibration dose was a useful parameter for quantitative exposure assessment and showed a dose-response relationship between exposure and symptoms when adjusted for confounding factors.

Adult↗