Exposure assessment to alpha- and beta-pinene,delta(3)-carene and wood dust in industrial production of wood pellets

The main aim of the study was to measure the exposure to monoterpenes (alpha- and beta-pinene and Delta(3)-carene) and wood dust during industrial production of wood pellets and briquettes. Additional aims were to compare the results from wood dust sampled on a filter with real time measurements using a direct reading instrument and to identify peak exposures to dust. Twenty-four men working at six companies involved in industrial production of wood pellets and briquettes participated in the study. Monoterpenes were measured by diffusive sampling and wood dust was measured as total dust. A data logger (DataRAM) was used for continuous monitoring of dust concentration for 18 of the participants. The sampling time was approximately 8 h. The personal exposure to monoterpenes ranged from 0.64 to 28 mg/m(3) and a statistically significant (Kruskal-Wallis test, P = 0.0002) difference in levels of monoterpenes for workers at different companies was seen. In the companies the personal exposure to wood dust varied between 0.16 and 19 mg/m(3) and for 10 participants the levels exceeded the present Swedish occupational exposure limit (OEL) of 2 mg/m(3). The levels of wood dust during the morning shift were significantly (Mann-Whitney test, P = 0.04) higher compared with the afternoon shift. Continuous registration of dust concentration showed peak values for several working operations, especially cleaning of truck engines with compressed air. For 24 workers in six companies involved in industrial production of wood pellets the personal exposure to monoterpenes was low and to wood dust high compared with the present Swedish OEL and previous studies in Swedish wood industries. Since the DataRAM can identify critical working tasks with high wood dust exposure a reduction in exposure levels could probably be achieved by changes in working routines and by the use of protective equipment.     

Insomnia and Its Relationship to Work and Health in a Working-Age Population

Because sleep may directly or indirectly be related to disability, we examined the prevalence of sleep problems in working-age people in the general population and explored the relationship among sleep, health, and work. A cross-sectional survey, mailed to 3,000 people aged 20–60, was employed, featuring criteria to define sleep problems and standardized items to assess work and health. Although the criteria for insomnia was met by 8% of the sample, the 3-month prevalence of sleep problems was 35%. Sleep was related to self-reported mental, physical, and social health as well as to health-care utilization. As for work, poor sleep was linked to absenteeism, employment status, work hours, and the psychosocial work environment. Moreover, poor sleep was associated with reduced work capacity, for example, reduced concentration, listlessness, and difficulties in making decisions. Multivariate analyses that controlled age, gender, and health factors found that not being employed and poor work-content increased the risk for sleep problems. We conclude that sleep problems are prevalent among working-age people and that there is a bilateral link between sleep and work. There is a need to develop treatment as well as preventive interventions oriented towards workers and the workplace.     

Cohort mortality study of Swedish pulp and paper mill workers-nonmalignant diseases

OBJECTIVES: The aim of this study was to determine mortality among pulp and paper mill workers according to the main mill pulping process, department, and gender, particular reference being given to diseases of the circulatory and respiratory systems. METHODS: The cohort of 18 163 men and 2 291 women employed between 1939 and 1999 and with >1 year of employment was followed for mortality from 1952 to 2001 (acute myocardial infarction from 1969). Standardized mortality ratios (SMR) with 95% confidence intervals (95% CI) were estimated by comparing the observed number of deaths with the expected number for the entire Swedish population. Exposure was assessed from personnel files in the mills. Data from an exposure measurement database are also presented. RESULTS: There were 5898 deaths in the cohort. Total mortality had an SMR of 1.02 (95% CI 0.98-1.06) for the men in the sulfate mills and an SMR of 0.93 (95% CI 0.90-0.97) for the men in the sulfite mills. Mortality from acute myocardial infarction was increased among the men in both the sulfate and sulfite mills [SMR 1.22 (95% CI 1.12-1.32) and SMR 1.11 (95% CI 1.02-1.21), respectively] and by department in sulfate pulping (SMR 1.29, 95% CI 1.07-1.54), paper production (SMR 1.26, 95% CI 1.06-1.49), and maintenance (SMR 1.16, 95% CI 1.02-1.30). Mortality from cerebrovascular disease, diabetes mellitus, and nonmalignant respiratory diseases was not increased. CONCLUSIONS: Death from acute myocardial infarction, but not cerebrovascular diseases, was increased in this cohort and was probably related to a combination of different occupational exposures (eg, dust, sulfur compounds, shift work, and noise).     

Burnout in the working population: relations to psychosocial work factors

This study investigated levels of burnout in the general population irrespective of occupation and relations between burnout and psychosocial work factors. A cross-sectional survey featuring sleep problems, psychological distress, burnout (Maslach Burnout Inventory-General Survey), and psychosocial factors at work, was mailed to a random sample of 3,000 participants, aged 20–60. Response rate was 61%. A high level (18%), a low level (19%), and an intermediate group (63%) for burnout were constructed. The high level group was associated with those who were > 50 years old, women, those experiencing psychological distress, and those with a poor psychosocial work climate. The analyses on variables significant in previous analyses showed that the high level group was strongly related to high demands, low control, lack of social support, and disagreeing about values at the workplace even when accounting for age, gender, and psychological distress. We conclude that psychosocial work factors are important in association to burnout regardless of occupation.     

Lower rates of thymidine incorporation into DNA of skin fibroblasts from patients with adenomatosis of the colon and rectum

Thymidine incorporation into DNA was examined in confluent fibroblastcultures which had been further arrested by 7–9 days'growth on 0.5% serum-supplemented medium. There were 13 fibroblastlines from patients with adenomatosis of the colon and rectum(ACR) and seven control fibroblast strains from unaffected relativesand spouses of ACR patients. After 24 h an ACR fibroblast strainshowed a decreased rate of unscheduled DNA synthesis (UDS),whereas no such effects were observed with the control fibroblaststrain. It was shown that the difference in UDS rates betweencontrol and ACR fibroblast strains was not due to [³H]-dThdcatabolism and/or disappearance in the culture medium aftera 34-h labelling period. When the percent increases in N-acetoxy-2-acetylaminofluorene(NA-AAF)-induced UDS and in [³H]-dThd incorporation in the presenceof 10 mM hydroxyurea were compared between 24 h and 34 h incubation,the 13 ACR fibroblast lines were significantly lower comparedto the corresponding values calculated for the seven controlfibroblast strains. The ACR fibroblasts also had significantlyelevated levels of spontaneous chromosome aberrations comparedto controls. Furthermore, the percent increase in NA-AAF-inducedUDS was negatively correlated with the level of spontaneouschromosome aberrations. These data suggest that there is a geneticinstability in the cells from ACR patients that can be estimatedby both UDS and cytogenetic analyses.     

Quartz and dust exposure in Swedish iron foundries

Exposure to respirable quartz continues to be a major concern in the Swedish iron foundry industry. Recommendations for reducing the European occupational exposure limit (EU-OEL) to 0.05 mg/m3 and the corresponding ACGIH(R) threshold limit value (ACGIH-TLV) to 0.025 mg/m3 prompted this exposure survey. Occupational exposure to respirable dust and respirable quartz were determined in 11 Swedish iron foundries, representing different sizes of industrial operation and different manufacturing techniques. In total, 436 respirable dust and 435 respirable quartz exposure measurements associated with all job titles were carried out and are presented as time-weighted averages. Our sampling strategy enabled us to evaluate the use of respirators in certain jobs, thus determining actual exposure. In addition, measurements using real-time dust monitors were made for high exposure jobs. For respirable quartz, 23% of all the measurements exceeded the EU-OEL, and 56% exceeded the ACGIH-TLV. The overall geometric mean (GM) for the quartz levels was 0.028 mg/m3, ranging from 0.003 to 2.1 mg/m3. Fettler and furnace and ladle repair operatives were exposed to the highest levels of both respirable dust (GM = 0.69 and 1.2 mg/m3; range 0.076-31 and 0.25-9.3 mg/m3 and respirable quartz (GM = 0.041 and 0.052 mg/m3; range 0.004-2.1 and 0.0098-0.83 mg/m3. Fettlers often used respirators and their actual quartz exposure was lower (range 0.003-0.21 mg/m3, but in some cases it still exceeded the Swedish OEL (0.1 mg/m3. For furnace and ladle repair operatives, the actual quartz exposure did not exceed the OEL (range 0.003-0.08 mg/m3, but most respirators provided insufficient protection, i.e., factors less than 200. In summary, measurements in Swedish iron foundries revealed high exposures to respirable quartz, in particular for fettlers and furnace and ladle repair workers. The suggested EU-OEL and the ACGIH-TLV were exceeded in, respectively, 23% and 56% of all measurements regardless of the type of foundry. Further work on elimination techniques to reduce quartz concentrations, along with control of personal protection equipment, is essential.