Occupational exposure to phenoxy herbicides and chlorophenols and cancer mortality in The Netherlands

As part of the "IARC International Register of Persons Exposed to Phenoxy Herbicides and Contaminants," a cohort of workers who manufacture and prepare chlorophenoxy herbicides was recruited in The Netherlands. The cohort comprised 2,310 workers from two plants, operated by different companies, who were followed during the periods 1955-1985 and 1965-1986, respectively. In 1963, there had been an industrial accident in one factory with concomitant release of dioxin into the environment. Loss to follow-up was 3%. Mortality data on 963 exposed and 1,111 nonexposed men were evaluated by external and internal comparison. Compared with national rates, total mortality (94 deaths, standardized mortality ratio [SMR] = 101; 95% confidence interval [CI], 82-124) and cancer mortality (31 deaths, SMR = 107; 95% CI, 73-152) for exposed workers were not significantly increased. A statistically insignificant increase was observed for non-Hodgkin's lymphoma (2 deaths, SMR = 299; 95% CI, 36-1,078). No cases of soft-tissue sarcoma were encountered. There was no increase in either total mortality (25 deaths, SMR = 111; 95% CI, 72-163) or cancer mortality (10 deaths, SMR = 137; 95% CI, 66-252) among the 139 workers probably exposed to dioxins during the 2,4,5-trichlorophenol production accident or the subsequent clean-up operations. Compared with nonexposed workers, exposed workers did not exhibit a higher total mortality (rate ratio [RR] = 1.28; 95% CI, 0.89-1.82). Mortality due to all cancers (RR = 1.7; 95% CI, 0.9-3.4) and respiratory cancer (RR = 1.7; 95% CI, 0.5-6.3) was insignificantly elevated. These findings suggest that the increases in cancer mortality among workers exposed to phenoxy herbicides and chlorophenols may be attributable to chance. Lack of power prevented evaluation with respect to specific cancers.     

Occupational exposure to organic solvents and sleep-disordered breathing

STUDY OBJECTIVE: To investigate whether people with occupational exposure to organic solvents have a higher prevalence of obstructive sleep apnea syndrome (OSAS) than the general population and to examine the relationship between snoring and exposure to organic solvents. DESIGN AND PARTICIPANTS: Consecutive patients, aged 30-64 years, referred during a 3-year period to the sleep laboratory at Avesta Hospital, Sweden, because of suspected OSAS made up the patient groups. Following admission, patients underwent a simplified sleep apnea investigation and were divided into two groups, OSAS (n = 320) and snorers (n = 443). A random sample of 296 men and 289 women aged 30-64 years obtained from a register of all country residents maintained by the county tax authority served as referents (controls). Both patients and referents responded to two questionnaires, including questions about occupation, exposure to organic solvents, and other chemical and physical agents. RESULTS: Men with OSAS or snoring and women with snoring had more often been occupationally exposed to organic solvents than the referents, showing an almost twofold increase in risk for those exposed during whole workdays. For men, the risk of OSAS or snoring increased with increasing exposure. CONCLUSION: The result indicates that occupational exposure to organic solvents might cause sleep apnea. A new observation is that even snoring could be caused by exposure to organic solvents. It is important to elucidate whether exposure to organic solvents is a cause of OSAS, because such a finding may have important implications for prevention and treatment of sleep disturbances.     

Occupational lead exposure and management

We report a series of 60 children operated on for posterior urethral valve (PUV) before the age of 5 years and followed up for 10 years. This work aims to study the vesico-sphincteric sequelae of this malformation. 38 patients showed early urinary incontinence post-operatively. Of them, 20 were re-evaluated 10 years later by pelvic ultrasonography, pressure flow studies combined with EMG and assessment of renal function. 8 patients refused to undergo these investigations and 10 were lost to follow-up. Of the 28 evaluable patients, 22 are currently continent and a complete urodynamic study was performed for the 6 (10%) incontinent patients. Of them, 3 showed uninhibited detrusor contractions. The vesical compliance was frequently within the normal limits. No case of detrusor-sphincteric dyssynergy or urethral hypotony was found. 2 were successfully treated by oxybutinin and biofeedback reeducation, 2 were partially improved but their prostates are still in growth and the possibility of implanting an artificial sphincter was discussed in the remaining 2. The urodynamic evaluation of those patients in the long-term is encouraging.     

Occupational exposure to drugs. General considerations]

The authors studied the ultrastructure of the esophagus lining epithelial cells of the snake Xenodon merremii. The initial shows ciliated wedge shaped cells and goblet cells which are gradually displaced by columnar ones in the posterior third of the organ. Other cellular types, such as basal, argentaffin and argyrophil cells can be found throughout the esophagus mucosa.     

Occupational blood exposures in dentistry: a decade in review

This review summarizes data from self-reported and observational studies describing the nature, frequency, and circumstances of occupational blood exposures among US dental workers between 1986 and 1995. These studies suggest that, among US dentists, percutaneous injuries have declined steadily over the 10-year period. Data also suggest that, in 1995, most dental workers (dentists, hygienists assistants, and oral surgeons) experienced approximately three injuries per year. Work practices (eg, using an instrument instead of fingers to retract tissue), safer instrumentation or design (eg, self-sheathing needles, changes in dental-unit design), and continued worker education may reduce occupational blood exposures in dentistry further.     

Occupational exposure to chromium and nickel in the 1980s in Finland

Two large data bases accumulated from the 1980s at the Finnish Institute of Occupational Health, one with results on urinary chromium and nickel analyses and the other with results on total and hexavalent chromium and nickel, were compiled and analysed in order to clarify the occupational exposure during the 1980s, and to reveal possible trends in the exposure of workers in different jobs. The data were processed in three batches: years 1980-1982, 1983-1985 and 1986-1989. The median values of urinary chromium exceeded the biomonitoring action level, BAL, in metal workers, and the mean values exceeded the BAL in both metal workers and plasma cutters. Among all worker groups the median values of urinary chromium remained quite stable during the study period. The median values of urinary nickel concentration did not exceed the BAL in any worker group studied, but an increasing trend was observed among moulders. In the breathing zone of grinders, the median value of total or trivalent chromium exceeded the occupational exposure limit, OEL. The medial of hexavalent chromium concentration in the breathing zone of metal sprayers and spray painters was higher than the OEL. No decreasing trend in exposure could be observed during the 10-year period in breathing zone air.     

Occupational exposure to xylene of workers employed in paint shops

The paper presents results of evaluation of exposure to xylene of workers employed in paint workshops of the Agricultural Machines Factory "Rofama". The evaluation has been made basing on the measurements of urinary methylhippuric acid. It was found that spray painting exerts the most harmful effect on the health of workers exposed to xylene.     

Occupational lead exposure and hearing loss

Studies of adults, children, and laboratory animals suggest an association between lead exposure and hearing loss. A causal relationship might direct mandated medical surveillance of lead-exposed workers to include audiometric testing. A cross-sectional, computerized dataset was obtained from a private occupational health screening company to examine the relationship between blood lead level and hearing loss. Audiometry and blood lead results were available for 183 workers. A statistically significant correlation was found between blood lead level and an elevated hearing threshold at 400 Hz (P = 0.03); no other frequencies showed such a correlation. This finding suggests either an interaction between nose exposure and lead, interaction of other exposure factors (such as cigarette smoking), or that factors other than biomechanical ones render the organ of Corti more susceptible at 4000 Hz. Further evaluation of these questions should be undertaken. Computerized databases created for worker surveillance may be a source for data useful for examining other causal connections in occupational settings.     

Occupational exposure to HIV: considerations for postexposure prophylaxis and prevention

HIV seroconversion as a result of an occupational exposure is a terrifying concern of healthcare workers who deliver care to patients in a variety of health care settings. In this article the most recent CDC guidelines for the management of HIV exposure and postexposure prophylaxis are reviewed. Prevention of bloodborne pathogen exposures, specifically through the selection of safety devices, is recognized as an important issue.     

Nutritional status and delayed mortality following early exposure to measles

Community studies in Guinea-Bissau have found that exposure to measles prior to 6 months of age is associated with delayed mortality later in childhood. In an attempt to understand the underlying mechanism, we examined the role of pre-exposure nutritional status and the impact of exposure to measles on growth and subsequent mortality in these outbreaks. Though exposed children were lighter than controls, there was no association between pre-exposure weight-for-age and subsequent mortality adjusting for age. Although exposure was strongly associated with excess mortality, it did not have a negative impact on growth. Adjustment for state of nutrition did not alter the mortality ratio (MR) between 6 and 59 months of age for exposed children and controls; exposed children examined anthropometrically between 6-17 months had a MR of 3.70 compared with controls. This trend was the same for anthropometric measurements obtained at 18-59 months of age. Among the controls, there was a significant association between weight-for-age and subsequent mortality to the age of 5 years. However, for exposed children there was no association; the relation between weight-for-age and subsequent mortality was significantly different for exposed children compared with controls (tests for interaction between exposure and anthropometric measurements at 6-17 months: P = 0.05). Growth faltering as a consequence of early exposure to measles does not explain the marked excess mortality among these children. Further studies of the process underlying delayed mortality after early exposure to measles are warranted.     

Occupational exposure of nonsmoking nightclub musicians to environmental tobacco smoke

This study assessed environmental tobacco smoke (ETS) exposures of nonsmoking musicians in nightclub environments using total suspended particulate (TSP), the ultraviolet absorbing fraction of TSP (UVPM), gaseous nicotine, saliva nicotine, saliva cotinine, and perceived smokiness as exposure/dose indicators. Measured exposures were as high or higher than those of other occupational groups studied. TSP ranged from 110 to 1714 micrograms/m3 (mean 502, SD 390 micrograms/m3). UVPM (mean 221, SD 95 micrograms/m3) was associated with gaseous and saliva nicotine concentrations. Paired-sample variation was much higher for TSP than for UVPM. Correlation of TSP with UVPM, gaseous nicotine, and saliva nicotine was poor. Paired-sample gaseous nicotine results were similar, with exposures of 28.0 to 50.0 micrograms/m3 (mean 37.1, SD 6.9 micrograms/m3), and were high compared with previous studies. These results suggested that nightclub musicians may be exposed to higher concentrations of ETS than some other occupational groups. Saliva nicotine results were consistent with those previously reported with regard to the range of values, large variation observed, and increase in saliva nicotine levels observable after only a few hours of exposure. Saliva nicotine results could not be correlated with other measures of exposure and did not appear to be a reliable biological indicator of absorbed dose. Saliva cotinine levels were comparable to other occupational groups studied, but were lower than previous findings for bartenders and waitresses. Levels ranged from 1.7 to 5.0 ng/mL (mean 3.4, SD 0.9 ng/mL), and increased with number of exposures during the workweek, but did not correlate with other ETS indicators.     

Neuropsychological functioning after mercury exposure.

Observed visuographic and paranoid symptomatology in 26 dentists (mean age, 49.9 yrs) with elevated mercury levels. Neuropsychological functions were assessed with measures such as the Wechsler Adult Intelligence Scale (WAIS), the Bender-Gestalt Test, and the SCL-90 (Revised). Although the observed changes were mild, their presence suggests subtoxic hazards associated with dental practice and underscore a continual need for maintaining mercury hygiene. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Occupational exposure to HIV: experience at a tertiary care center

We examined our hospital-based occupational health clinic's experience with combination antiretroviral therapy for postexposure prophylaxis for human immunodeficiency virus (HIV). Over a 12-month period, 68 workers started postexposure prophylaxis: 23 with zidovudine and lamivudine and 45 with zidovudine, lamivudine, and indinavir. Fifty-one (75%) of the 68 workers starting postexposure prophylaxis reported one or more side effects. Side effects were more common among those taking three drugs. Many workers failed to complete the recommended 28-day regimen because of the side effects of the various treatments. The estimated mean cost for evaluations, prophylaxis, and monitoring of exposed workers was $669 per reported exposure. In our experience, major challenges in carrying out the current HIV postexposure prophylaxis guidelines include expeditious source testing, improved staff education and prevention measures, and scrupulous monitoring of workers taking combination antiretroviral drugs for postexposure prophylaxis, with consideration of alternate regimens for intolerant workers.     

Occupational exposure to inhalation anesthetics at the work-place of veterinary surgery

In a prospective study we evaluated the work-place pollution by isoflurane and nitrous oxide during various anaesthetic procedures in animal surgery. The study was conducted during one working week at an University Animal Department. Trace concentrations of isoflurane and nitrous oxide were directly measured every minute in the breathing zone by means of a photoacoustic infrared spectrometer in two different operating rooms (OR) with an air turnover of 17 changes per hour. In one OR the 8-hour time-weighted average (mean +/- SEM) was calculated to be 12.3 +/- 9.9 ppm nitrous oxide and 1.9 +/- 2.5 ppm isoflurane. The other OR, where only isoflurane was used, was contaminated with 5.3 +/- 8.1 ppm isoflurane. In the first OR, the trace gas concentrations were low and comparable to values obtained under human anaesthesia in adults and children. The higher contamination in the second OR resulted from performing inhalational anaesthesia with an open mask system in birds and small animals. Although the mean values were below the recommended occupational exposure standards, some high peak values (> 300 ppm isoflurane) violated these threshold limits. We recommend the use of a local scavenging device, if other alternatives such as total intravenous anaesthesia are not possible.     

Occupational exposure to HIV, hepatitis B, hepatitis C, and tuberculosis

This article reviews risk of occupational exposure to bloodborne pathogens, specifically HIV, hepatitis B, and hepatitis C to healthcare workers. Information regarding assessing the risk of exposure, appropriate actions to take if an exposure occurs, the most recent recommendations for treatment and follow-up postexposure, and prevention strategies for avoiding exposure are presented. Additionally, current recommendations for the prevention of the transmission of tuberculosis in healthcare workers and the regulatory guidelines governing this topic are discussed.