Bjørn Hilt

Increase in interleukin-6 and fibrinogen after exposure to dust in tunnel construction workers

Objectives: To see if there is any change in blood concentrations of interleukin-6 (IL-6) and fibrinogen during a working shift in tunnel construction workers. Methods: 12 Tunnel construction workers were followed up during a 24 hours period after returning from a 9 day work free period. The first blood sample was taken on Monday afternoon before starting the shift. Another was taken around midnight after 8 hours of work, and another the next afternoon after about 12 hours of rest. Exposure to respirable dust was measured by personal samplers. Results: The exposure of the workers to respirable dust, in terms of an 8 hour time weighted average, varied between 0.3 and 1.9 mg/m3. For IL-6, there was an increase in the median serum concentration from 1.14 ng/l before starting the shift to 4.86 ng/l after 8 hours of work (p=0.002). For fibrinogen, there was an increase in the median concentration from 3.40 g/l before entering the shift to 3.70 g/l 24 hours later (p=0.044). There was a positive correlation between values of IL-6 at the end of the working shift and the fibrinogen concentrations the next afternoon (Pearsons R=0.73, p=0.007). The observed increase in IL-6 was significant for both smokers and non-smokers. Conclusion: The study shows an increase in both IL-6 and fibrinogen concentrations during a working shift for both smoking and non-smoking tunnel construction workers.

Lung function and respiratory symptoms in subjects with asbestos-related disorders: A cross-sectional study

The prevalence of respiratory symptoms and lung function impairment was studied in a sample of men from a population screening of asbestos-related disorders. When the rates were adjusted for age and smoking habits, 83 subjects with lung fibrosis had an increased prevalence of respiratory symptoms, in particular, phlegm when coughing and breathlessness grades 1-3. Among 200 subjects under 70 years of age who had pleural plaques only, a statistically significant increase was observed in the prevalence of breathlessness grade 1 compared to an external reference population. Among 98 asbestos-exposed subjects who had normal chest X-rays, there was an increase in the prevalence of breathlessness grade 2, cough during the day, and phlegm when coughing. There was a higher proportion of subjects with lung fibrosis who were below 80% of the predicted values for forced vital capacity (FVC) and forced expiratory volume in 1 second (FEV1) than in the other groups. There was also a higher proportion of subjects with pleural plaques only who were below 90% of the predicted value for FVC than in a group of 90 subjects without asbestos exposure. In accordance with previous studies, these results indicate that pleural plaques in asbestos workers may be of greater importance as a clinical feature than has been recognized in the past.

Short term exposure to cooking fumes and pulmonary function

BackgroundExposure to cooking fumes may have different deleterious effects on the respiratory system. The aim of this study was to look at possible effects from inhalation of cooking fumes on pulmonary function.MethodsTwo groups of 12 healthy volunteers (A and B) stayed in a model kitchen for two and four hours respectively, and were monitored with spirometry four times during twenty four hours, on one occasion without any exposure, and on another with exposure to controlled levels of cooking fumes.ResultsThe change in spirometric values during the day with exposure to cooking fumes, were not statistically significantly different from the changes during the day without exposure, with the exception of forced expiratory time (FET). The change in FET from entering the kitchen until six hours later, was significantly prolonged between the exposed and the unexposed day with a 15.7% increase on the exposed day, compared to a 3.2% decrease during the unexposed day (p-value = 0.03). The same tendency could be seen for FET measurements done immediately after the exposure and on the next morning, but this was not statistically significant.ConclusionIn our experimental setting, there seems to be minor short term spirometric effects, mainly affecting FET, from short term exposure to cooking fumes.

Skin disorders in ship's engineers exposed to oils and solvents

Ships engineers are exposed to mineral oil and solvents in their work. This study was intended to investigate if ships engineers had an increased prevalence of skin disorders and whether any such increased risk could be linked lo exposure to mineral oils and solvents. A self‐administered questionnaire was sent to 700 male seamen from 3 Norwegian ferry companies. Of the 492 respondents. 169 were currently working as ships engineers and 295 had never worked as ships engineers, The outcomes eczema, acne, dry skin, a in dermatitis and hand dermatitis were defined from the questionnaire. Prevalences of these skin disorders were compared between the groups. Logistic regression was used to elucidate explanatory variables further. When comparing current ships engineers with those who had never worked as ships engineers, the crude prevalence ratios were 1.7 (95% CI 1.1–2.7) for dry skin. 1.7 (95%CI 1.1 2.5) for any dermatitis. 1.3(95%CI 0.66–2.67) for acne and 1.2 (CI 0.61–2.27) for eczema. The risk of these symptoms increased for the engineers in the regression analysis, after controlling for age, self‐reported use of Stoddard solvent, and the use of fuel oil as a hand cleansing agent. The increased prevalence of skin disorders found among ships engineers in this investigation may be explained by direct contact with mineral oils and solvents.

Pregnancy Outcomes among Female Dental personnel-a registry-based Retrospective Cohort Study

OBJECTIVES The aim of this study was to investigate whether women who have worked as dental personnel in Norway, a group with possible previous exposure to mercury vapor, have had an excess risk of having children with congenital malformations or other adverse pregnancy outcomes compared to the general population. METHODS A cohort of female dental personnel was identified from the archives of the public dental healthcare and the national trade unions in Norway. Data on births and pregnancy outcomes during 1967-2006 were obtained from the Medical Birth Registry of Norway (MBRN). The final cohort of dental personnel consisted of 4482 dental assistants and 1011 dentists. All other women registered in the MBRN were assigned to the control group, in total 1,124,758. Excess risks of several adverse pregnancy outcomes for dental personnel compared to the general population were estimated. Analyses were conducted for the whole time period as well as stratified by 10-year periods. RESULTS Female dental personnel had no observed increased occurrence of congenital malformations (including malformations of the central nervous system, dysplasia of the hip, clubfoot, malformations of the heart and great vessels), low birth weight, preterm birth, small for gestational age, changed gender ratio, multiple birth, stillbirth, or prenatal death. CONCLUSION On a group level, we did not observe any excess risks of congenital malformations or other adverse pregnancy outcomes among female dental personnel in Norway during 1967-2006 compared to the general population.

Health survey of former workers in a Norwegian coke plant: Part 2. Cancer incidence and cause specific mortality.

OBJECTIVES: A Norwegian coke plant that operated from 1964 to 1988 was investigated to ascertain whether the male workers in this plant had increased morbidities of cancer or increased mortality from specific causes, particularly associated with specific exposures at the coke plant. METHODS: Personal data on all the employees of the plant were obtained from the plants archives. With additional data from the Norwegian Bureau of Statistics we identified 888 male former workers at the plant. Causes of death were obtained from the Norwegian Bureau of Statistics, and cancer diagnoses from the Norwegian Cancer Registry. The results were compared with national averages adjusted for age. Specific exposures were estimated with records of actual measurements done at the plant and interviews with former workers at the plant. RESULTS: A significant excess of stomach cancer (standardised incidence ratio (SIR) 2.22, 95% confidence interval (95% CI) 1.01 to 4.21) was found. Mortality from ischaemic heart disease and sudden death was positively associated with work in areas which entailed peak exposures to CO. When considering work in such areas the past 3 years before death, the association was significant (p = 0.01). The last result is based on only two deaths. CONCLUSIONS: Considering the short follow up time and the small size of the cohort the results should be interpreted with a certain caution. The positive results would justify a re-examination of the cohort at a later date.

Exposure to mineral oil mist and respiratory symptoms in marine engineers.

The purpose of the study was to see if marine engineers have an increased prevalence of respiratory symptoms, and if so whether it can be related to occupational exposures. A self-administered questionnaire was sent to 700 male seamen from three Norwegian ferry companies. Of the 492 respondents, 169 were currently working as marine engineers and 295 had never worked as marine engineers. The outcomes of cough and wheezing, chronic bronchitis, severe dyspnea, any dyspnea, and mucous membrane irritation (MMI) were defined from the questionnaire. Age and smoking-adjusted prevalences of these respiratory conditions were compared between the groups. Logistic regression was used to further elucidate the explanatory variables. The exposure assessment indicated an exposure (TWAC) to oil mist for marine engineers in the range from 0.12 to 0.74 mg/m3 (mean 0.45 mg/m3) When comparing current marine engineers with those who had never worked as marine engineers, the prevalence ratios were 1.38 (95% CI 1.0-1.9) for MMI, 1.53 (95% CI 1.2-1.9) for any dyspnea, and 1.63 (95% CI 1.0-2.6) for severe dyspnea. The differences remained for some of the symptoms after controlling for self-reported former asbestos exposure in the regression analysis. The increased prevalence of respiratory symptoms found among marine engineers in this investigation may partly be explained be oil-mist exposure, or more probably by a combination of past asbestos exposure and past and present oil-mist exposure.

Inflammatory Markers in Blood and Exhaled Air after Short-Term Exposure to Cooking Fumes

Objectives: Cooking fumes contain aldehydes, alkanoic acids, polycyclic aromatic hydrocarbons, and heterocyclic compounds. The inhalation of cooking fumes entails a risk of deleterious health effects. The aim of this study was to see if the inhalation of cooking fumes alters the expression of inflammatory reactions in the bronchial mucosa and its subsequent systemic inflammatory response in blood biomarkers. Methods: Twenty-four healthy volunteers stayed in a model kitchen on two different occasions for 2 or 4h. On the first occasion, there was only exposure to normal air, and on the second, there was exposure to controlled levels of cooking fumes. On each occasion, samples of blood, exhaled air, and exhaled breath condensate (EBC) were taken three times in 24h and inflammatory markers were measured from all samples. Results: There was an increase in the concentration of the d-dimer in blood from 0.27 to 0.28mg ml–1 on the morning after exposure to cooking fumes compared with the levels the morning before (P-value = 0.004). There was also a trend of an increase in interleukin (IL)-6 in blood, ethane in exhaled air, and IL-1β in EBC after exposure to cooking fumes. In a sub-analysis of 12 subjects, there was also an increase in the levels of ethane—from 2.83 parts per billion (ppb) on the morning before exposure to cooking fumes to 3.53 ppb on the morning after exposure (P = 0.013)—and IL-1β—from 1.04 on the morning before exposure to cooking fumes to 1.39 pg ml–1 immediately after (P = 0.024). Conclusion: In our experimental setting, we were able to unveil only small changes in the levels of inflammatory markers in exhaled air and in blood after short-term exposure to moderate concentrations of cooking fumes.

Neuropsychological function and past exposure to metallic mercury in female dental workers.

The aim of this study was to see if dental personnel with previous exposure to metallic mercury have later developed disturbances in cognitive function. Ninety-one female participants who had been selected from a previous health survey of dental personnel were investigated neuropsychologically within the following domains: motor function, short-term memory, working memory, executive function, mental flexibility, and visual and verbal long-term memory. The scores were mainly within normal ranges. Relationships between an exposure score, the duration of employment before 1990, and previously measured mercury in urine as independent variables and the neuropsychological findings as dependent variables, were analyzed by multiple linear regression controlling for age, general ability, length of education, alcohol consumption, and previous head injuries. The only relationship that was statistically significant in the hypothesized direction was between the previously measured urine mercury values and visual long-term memory, where the urine values explained 30% of the variability. As the study had a low statistical power and also some other methodological limitations, the results have to be interpreted with caution. Even so, we think it is right to conclude that neuropsychological findings indicative of subsequent cognitive injuries are difficult to find in groups of otherwise healthy dental personnel with previous occupational exposure to mercury.

Anxiety and depression symptoms among farmers. The HUNT Study, Norway.

ABSTRACT Agriculture has undergone profound changes, and farmers face a wide variety of stressors. Our aim was to study the levels of anxiety and depression symptoms among Norwegian farmers compared with other occupational groups. Working participants in the HUNT3 Survey (The Nord-Trøndelag Health Study, 2006–2008), aged 19–66.9 years, were included in this cross-sectional study. We compared farmers (women, n = 317; men, n = 1,100) with HUNT3 participants working in other occupational groups (women, n = 13,429; men, n = 10,026), classified according to socioeconomic status. We used the Hospital Anxiety and Depression Scale (HADS) to measure anxiety and depression symptoms. Both male and female farmers had higher levels of depression symptoms than the general working population, but the levels of anxiety symptoms did not differ. The differences in depression symptom levels between farmers and the general working population increased with age. In an age-adjusted logistic regression analysis, the odds ratio (OR) for depression caseness (HADS-D ≥8) when compared with the general working population was 1.49 (95% confidence interval [CI]: 1.22–1.83) in men and 1.29 (95% CI: 0.85–1.95) in women. Male farmers had a higher OR of depression caseness than any other occupational group (OR = 1.94, 95% CI: 1.52–2.49, using higher-grade professionals as reference). Female farmers had an OR similar to men (2.00, 95% CI: 1.26–3.17), but lower than other manual occupations. We found that farmers had high levels of depression symptoms and average levels of anxiety symptoms compared with other occupational groups.