Scandinavian Journal of Work, Environment & Health, May 2, 2012
Objective It has been hypothesized that the underlying mechanism of elevated breast cancer risk a... more Objective It has been hypothesized that the underlying mechanism of elevated breast cancer risk among longterm, night-working women involves circadian genes expression alteration caused by exposure to light at night and/or irregular work hours. The aim of the present study was to determine the effect of rotating night shift work on expression of selected core circadian genes. Methods The cross-sectional study was conducted on 184 matched nurses and midwives, who currently work either day or rotating night shifts, to determine the effect of irregular work at night on circadian gene expression in peripheral blood leukocytes. Transcript levels of BMAL1, CLOCK, CRY1, CRY2, PER1, PER2, and PER3 were determined by means of quantitative real-time polymerase chain reaction (PCR). Results After adjusting for hour of blood collection, there were no statistically significant changes of investigated circadian genes among nurses and midwives currently working rotating night shifts compared to nurses working day shifts. The highest expression of PER1 messenger ribonucleic acid (mRNA) was observed for women currently working shifts who had worked >15 years in rotating night shift work. PER1 gene expression was associated with the lifetime duration of rotating night shift work among women currently working night shifts (P=0.04). PER1 and PER3 transcript levels in blood leukocytes were significantly down-regulated in the later versus early hours of the morning between 06.00-10.00 hours (β-coefficient-0.226, P=0.001 and β-coefficient-0.181, P<0.0001, respectively). Conclusions These results suggest that current rotating night shift work does not affect circadian gene expression in human circulating leukocytes. In analysis of the peripheral clock in human studies, the hour of blood collection should be precisely specified.
Occupational and Environmental Medicine, Aug 1, 1993
The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg... more The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg) in whole blood, urinary mercury (U-Hg), and selenium in urine (U-Se) and whole blood (B-Se) were determined in 74 chloralkali workers previously exposed to Hg vapour, and compared with 51 age matched referents. Dental amalgam state, fish consumption, and exposure related indices were studied with regard to the determined elements. A significant relation between the surface of dental amalgam and U-Hg (Pearson's r = 0*63, p < 0.001) was found among the referents. Mean USe was significantly lower (p < 0.001) among the subjects previously exposed to Hg (34.1 nmolmmol creatinine) compared with that for the referents (42.6 nmollmmol creatinine). A significant negative relation between the cumulative Hg dose and USe was also found. The mechanisms and the clinical significance of these findings are not clear. No relation between current U-Hg and previous occupational exposure to Hg was found among subjects in whom exposure had ceased more than one year before the study.
A competent assessment of causal relationships in the case of work-related lung disorders depends... more A competent assessment of causal relationships in the case of work-related lung disorders depends on correct diagnosis, a detailed occupational history and updated epidemiological knowledge about causal relationships, obtained from the literature. Assessments for purposes of compensation demand, in addition, an explicit choice of methods for calculating causes, before a meaningful attempt can be made to weight the various factors in and outside the working environment. If adequate epidemiological knowledge is available, the causal probability, based on the etiological fraction among the exposed persons (attributable risk) may be a useful tool for apportioning the different causal factors.
We have investigated the relationship between annual decline in forced expiratory volume in one s... more We have investigated the relationship between annual decline in forced expiratory volume in one second (∆FEV 1) and bronchial responsiveness (BR) in aluminium potroom workers. BR was measured in a cross-sectional study of 337 aluminium potroom workers halfway through a 6 yr follow-up study of lung function. A skin-prick test (SPT) was also performed. During follow-up the mean number of measurements of lung function (FEV 1) in each subject was 6.8. Mean ∆FEV 1 was 21.3 ml•yr-1 (within subject SD=30.5 ml•yr-1). Mean ∆FEV 1 was 57.0, 44.5 and 16.6 ml•yr-1 in subjects who had provocative concentration producing a 20% fall in FEV 1 (PC 20) ≤8.0, 8.1-32.0 and >32.0 mg•ml-1 , respectively. After adjustment for gender, atopy, smoking habit, FEV 1 , age and familial asthma the association between BR and ∆FEV 1 was weakened, and was not statistically significant. A significantly accelerated decline in FEV 1 with age was found. The difference in ∆FEV 1 between smokers and nonsmokers was 39.3 ml•yr-1 , and between subjects who had a positive skin-prick test compared to subjects with a negative skin-prick test 39.6 ml•yr-1. In subjects reporting work-related asthmatic symptoms the decline in FEV 1 was 43.2 ml•yr-1 greater than in asymptomatic subjects. In asymptomatic subjects, positive skin-prick test was also associated with increased ∆FEV 1. These data indicate that a single measurement of BR is not a predictor of ∆FEV 1 in aluminium potroom workers. Smoking, work-related asthmatic symptoms, and positive reaction to skin-prick test in asymptomatic workers were risk factors of increased ∆FEV 1 .
We studied pulmonary and auditory function in a cross-sectional study of 26 experienced construct... more We studied pulmonary and auditory function in a cross-sectional study of 26 experienced construction divers compared with 26 workshop workers matched for age, height, and smoking habits. The divers used air as breathing gas and performed open-sea bounce dives to a maximum of 50 m in sea water. The mean number of dives over a mean diving period of 20 yr (SD = 11) was 4746 (SD = 4743) (Range: 450-17000). Assessment of lung function included dynamic lung volume and flow and diffusion capacity (transfer factor) for carbon monoxide (TlCO). The auditory examination was performed measuring air conduction thresholds in a cabin. The results show a significantly higher mean forced vital capacity (FVC) of 6.01 L (SD = 0.88) in the divers compared with 5.67 L (SD = 0.84) (p = 0.045) in the controls, and an alveolar volume (VA) of 7.74 L (SD = 0.99) in the divers compared with 7.35 L (SD = 0.74) (p = 0.035) in the controls. There was a nonsignificant reduction in forced mid-expiratory flow rate (FEF25-75%) and a significant reduction in forced expiratory flow rate at 50% of FVC (FEF50%) among the divers of 4.69 L (SD = 1.41) compared with 5.76 L (SD = 2.03) among the controls of (p = 0.03). There were no differences in FEV1 and TlCO between the two groups. The divers showed reduced auditory function in their left ear compared with their right ear in the 3 kHz (p = 0.006) and 8 kHz (p = 0.022) area. No statistical difference was found in hearing thresholds of the divers compared with those of the controls. Our results indicate that exposure to diving may be associated with changes in pulmonary function and that the left ear may be more vulnerable than the right ear to hearing impairment in construction divers.
The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working grou... more The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working group to standardise diagnostic procedures and evaluation of work-related respiratory disorders. In cases of suspected work-related diseases the physician may be asked by the National Insurance Administration or an insurance company to make a statement which will be one of the documents used to decide the patient's right to compensation benefit. We discuss the role of the physician as an independent expert. This is different from his role as clinician. The statement should include a balanced presentation of information from different sources, including health and occupational history, and the employer's information about the work environment (quantitative and qualitative exposure data). The statement must also include the results of a clinical examination and an assessment of functional status based on objective tests. The paper contains recommendations for evaluation of permanent impairment in light of the present Norwegian laws and regulations.
Scandinavian Journal of Clinical & Laboratory Investigation, 2000
There is need for relevant markers of bronchial inflammation in epidemiologic studies of asthma. ... more There is need for relevant markers of bronchial inflammation in epidemiologic studies of asthma. Serum eosinophil cationic protein (ECP) is a marker of eosinophil inflammation and asthma activity. We have studied serum ECP in atopic farmers with current asthma, in non-atopic asthmatics and in non-asthmatic, non-atopic controls. In a cross-sectional study of a representative sample of 8,482 farmers in Norway, asthma was recorded using a self-administered questionnaire; spirometry and serum sampling were performed on all of them. Atopy was screened with Phadiatop and RAST analyses to the mites Lepidoglyphus destructor and Tyrophagus putrescentiae in all asthma cases and controls. All the identified atopics had additional RAST analyses on a set of allergens. Serum ECP was tested in 60 persons with current asthma and atopy (mean 16.2, 95% CI 13.2-19.3), 127 non-atopic asthmatics (mean 9.1, 95% CI 8.0-10.2) and 39 non-atopic controls (mean 5.5, 95% CI 4.0 7.0). ECP levels in atopic asthmatics were associated with number of positive allergens and reduction of FEVI values. Moreover, the ECP levels were elevated with allergy to swine, cow, D. pteronyssinus, L. destructor, A. siro, T. putrescentiae, timothy grass and the cereal grains: wheat, oat, barley and rye. Serum ECP seems feasible as an indicator of inflammatory activity in epidemiological studies of current allergic asthma, and may help to indicate the importance of specific allergens. Although the ECP values were significantly more elevated in atopic than in non-atopic asthma, elevated serum ECP was not specific for atopic asthma.
Scandinavian Journal of Work, Environment & Health, Oct 1, 1997
Objectives This study examined ~nortality froin noninalignant respiratory diseases among ferroall... more Objectives This study examined ~nortality froin noninalignant respiratory diseases among ferroalloy workers. Methods The cohort comprised 14 730 men employed for the first time in 1933-1990 and for at least 6 months in 1 of 12 plants. The duration of work in specific departments and exposure to amorphous silica in the ferrosiliconlsilicon-metal (FeSiISi-met) plants, estimated from a job-exposure matrix, were the main exposure variables. Deaths were observed during 1962-1990. The n~ortality was analyzed with the use of standardized mortality ratios (SMR) and internal comparisons of rates. Results Overall mortality from nonrnalignant respiratory diseases was not increased, but mortality from bronchitis, eillphyseina, and asthma combined was significantly increased among the men with at least 3 years of FeSiISi-met furnace work (SMR 1.82, 16 deaths). A Poisson regression analysis of the mortality from these causes among 6359 employees in the FeSiISi-met plants showed a significant increase of 0.06 per unit of amorphous silica exposure observed 10-20 years after the exposure. Six men died of pneumonia while still employed in a ferroinanganeselsilicomanganese (FeMnISiMn) plant. No corresponding deaths occurred among employees in FeSiISi-met plants. Only 2 deaths from pne~unoconiosis were observed in the total cohort. ~o~C~U S~O I I S Among employees in FeSiISi-met plants increased mortality from bronchitis, emphysema, and asthma nay be associated with previous exposure to an~orphous silica. Deaths from pneumonia among FeMnI SiMn workers may be associated with manganese exposure.
Sammendrag: Bakgrunn Akrylamidholdige tetningsmidler (Rhoca-Gil/Siprogel) har vært brukt i en rek... more Sammendrag: Bakgrunn Akrylamidholdige tetningsmidler (Rhoca-Gil/Siprogel) har vært brukt i en rekke større tunnelprosjekter i Norge sent på 1980-tallet og tidlig på 1990-tallet. I forbindelse med rapportering av mulige helseskader på grunn av akrylamideksponering i Romeriksporten høsten 1997, ble det reist spørsmål om andre tunnelarbeidere også kunne ha pådratt seg helseskader etter bruk av akrylamidholdige tetningsstoffer. Metode Vi har undersøkt effekter på nervesystemet, og andre helseeffekter hos 50 tunnelarbeidere tidligere eksponert for akrylamid og N-methylolakrylamid under tunnelarbeid. Femti tunnelarbeidere som ikke hadde arbeidet med akrylamidholdige tetningsstoffer var kontrollgruppe. De besvarte spørreskjema om symptomer og eksponering, gjennomgikk nevropsykologisk undersøkelse, fikk målt nerveledningshastighet i armer og ben, fargesyn og synsfelt, samt visuelt utløste responser (VEP) og elektroretinografi (ERG). Resultater De eksponerte arbeiderne rapporterte økt forekomst av symptomer sammenlignet med kontrollgruppen. Nevropsykologisk undersøkelse avdekket ingen gruppeforskjeller. Neurografi viste få forskjeller mellom gruppene. Det var imidlertid signifikant reduksjon i sensorisk nerveledningshastighet i n.suralis, og hos flere av de eksponerte lot sensorisk svarpotensial seg ikke fremkalle i denne nerven. Ved testing av fargesyn var eksponert gruppe litt svakere til å sortere blånyanser, samtidig som amplitudene ved elektroretinografi ved fotoptisk (30 Hz) stimulering var lett, men ikke statistisk signifikant redusert sammenlignet med kontrollgruppen. Ved synsfeltundersøkelse var terskel for å se enkle stimuli signifikant høyere i sentralt i synsfeltet hos de eksponerte enn hos kontrollene. I tillegg var det samlet sett tegn til en signifikant høyere terskel for å se lysstimuli i en ring ca. 20 ut til siden fra fovea. Konklusjon Resultatene indikerer en mulig lett vedvarende redusert sensorisk nerveledningshastighet i suralisnerven i bena hos de akrylamideksponerte tunnelarbeiderne sammenlignet med kontrollgruppen. En lett svekket fargediskrimineringsevne for blåtoner, samt svekket lyssensitivitet i fovea kan indikere lett vedvarende affeksjon av fotoreseptorer (tapper) sentralt i retina (fovea), noe som også understøttes ved lette forandringer ved elektroretinografi.
Occupational and Environmental Medicine, Aug 1, 1996
Objectives-Concern about the health hazards of exposure to workers in the ferroalloy industry has... more Objectives-Concern about the health hazards of exposure to workers in the ferroalloy industry has initiated this historical cohort study. The aim was to examine the mortality pattern among male employees in 12 Norwegian ferroalloy plants. Methods-All men employed for at least six months who started their first employment during 1933-91 were eligible for the cohort. Deaths observed during 1962-90 were compared with expected figures calculated from national mortalities. Internal comparisons of rates were performed by Poisson regression analysis. The final cohort comprised 14 730 male employees who were observed for 288 886 person-years. Results-Mortality from all causes of death was slightly increased (3390 deaths, standardised mortality ratio (SMR) 1-08, 95% confidence interval (95% CI) 1.04-1.11). Regression analysis of total mortality showed a significant negative trend for the rate ratios with increasing duration of employment. An increased mortality was found among employees in urban plants compared with employees in rural plants (rate ratio (RR) 1-21, 95% CI 1.13-1.29). Excess deaths from cancer (SMR 1 11) and sudden death (SMR 1.47) were found among employees with at least three years of employment. Mortality from accidents, poisonings, and violence was increased among all employees (SMR 1*28). Excess deaths from this cause were however only found for the time after the end of employment in this industry and not during employment (SMR 0.90). Conclusions-The increased mortality from cancer and sudden death could be related to work exposures, at least in subgroups, and these results warrant further studies. The excess deaths from accidents, poisonings, and violence were probably not related to work exposures. The mortality results for short term workers and other information indicate that systematic errors contribute to the increased overall mortality.
Occupational and Environmental Medicine, Aug 1, 1993
A cross sectional study of aspects of their neurology was carried out on 77 chloralkali workers p... more A cross sectional study of aspects of their neurology was carried out on 77 chloralkali workers previously exposed to mercury (Hg) vapour and compared with 53 age matched referents. The chloralkali workers had been exposed for an average of 7 9 years at a con
Occupational and Environmental Medicine, Sep 1, 2002
Aims: To analyse longitudinal changes in pulmonary function in professional divers and their rela... more Aims: To analyse longitudinal changes in pulmonary function in professional divers and their relation with cumulative diving exposure. Methods: The study included 87 men at the start of their education as professional divers. At follow up one, three, and six years later, 83, 81, and 77 divers were reexamined. The median number of compressed air dives in the 77 divers over the follow up period was 196 (range 37-2000). A group of non-smoking policemen (n = 64) were subjected to follow up examinations in parallel with the divers. Assessment of lung function included dynamic lung volumes, maximal expiratory flow rates, and transfer factor for carbon monoxide (Tl CO). The individual rates of change of the lung function variables were calculated by fitting linear regression lines to the data, expressed as percent change per year. Results: The annual reductions in forced vital capacity (FVC) and forced expired volume in one second (FEV 1) were 0.91 (SD 1.22) and 0.84 (SD 1.28) per cent per year in divers, which were significantly higher than the reductions in the policemen of 0.24 (SD 1.04) and 0.16 (SD 1.07) per cent per year (p < 0.001). The annual reduction in the maximal expiratory flow rates at 25% and 75% of FVC expired (FEF 25% and FEF 75%) were related to the log 10 transformed cumulative number of dives in a multiple regression analysis (p < 0.05). The annual reductions in Tl CO were 1.33 (SD 1.85) and 0.43 (SD 1.53) per cent per year in divers and policemen (p < 0.05). Conclusions: FVC, FEV 1 , maximal expiratory flow rates, and Tl CO were significantly reduced in divers over the follow up period when compared with policemen. The contrasts within and between groups suggest that diving has contributed to the reduction in lung function.
Scandinavian Journal of Work, Environment & Health, May 2, 2012
Objective It has been hypothesized that the underlying mechanism of elevated breast cancer risk a... more Objective It has been hypothesized that the underlying mechanism of elevated breast cancer risk among longterm, night-working women involves circadian genes expression alteration caused by exposure to light at night and/or irregular work hours. The aim of the present study was to determine the effect of rotating night shift work on expression of selected core circadian genes. Methods The cross-sectional study was conducted on 184 matched nurses and midwives, who currently work either day or rotating night shifts, to determine the effect of irregular work at night on circadian gene expression in peripheral blood leukocytes. Transcript levels of BMAL1, CLOCK, CRY1, CRY2, PER1, PER2, and PER3 were determined by means of quantitative real-time polymerase chain reaction (PCR). Results After adjusting for hour of blood collection, there were no statistically significant changes of investigated circadian genes among nurses and midwives currently working rotating night shifts compared to nurses working day shifts. The highest expression of PER1 messenger ribonucleic acid (mRNA) was observed for women currently working shifts who had worked >15 years in rotating night shift work. PER1 gene expression was associated with the lifetime duration of rotating night shift work among women currently working night shifts (P=0.04). PER1 and PER3 transcript levels in blood leukocytes were significantly down-regulated in the later versus early hours of the morning between 06.00-10.00 hours (β-coefficient-0.226, P=0.001 and β-coefficient-0.181, P<0.0001, respectively). Conclusions These results suggest that current rotating night shift work does not affect circadian gene expression in human circulating leukocytes. In analysis of the peripheral clock in human studies, the hour of blood collection should be precisely specified.
Occupational and Environmental Medicine, Aug 1, 1993
The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg... more The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg) in whole blood, urinary mercury (U-Hg), and selenium in urine (U-Se) and whole blood (B-Se) were determined in 74 chloralkali workers previously exposed to Hg vapour, and compared with 51 age matched referents. Dental amalgam state, fish consumption, and exposure related indices were studied with regard to the determined elements. A significant relation between the surface of dental amalgam and U-Hg (Pearson's r = 0*63, p < 0.001) was found among the referents. Mean USe was significantly lower (p < 0.001) among the subjects previously exposed to Hg (34.1 nmolmmol creatinine) compared with that for the referents (42.6 nmollmmol creatinine). A significant negative relation between the cumulative Hg dose and USe was also found. The mechanisms and the clinical significance of these findings are not clear. No relation between current U-Hg and previous occupational exposure to Hg was found among subjects in whom exposure had ceased more than one year before the study.
A competent assessment of causal relationships in the case of work-related lung disorders depends... more A competent assessment of causal relationships in the case of work-related lung disorders depends on correct diagnosis, a detailed occupational history and updated epidemiological knowledge about causal relationships, obtained from the literature. Assessments for purposes of compensation demand, in addition, an explicit choice of methods for calculating causes, before a meaningful attempt can be made to weight the various factors in and outside the working environment. If adequate epidemiological knowledge is available, the causal probability, based on the etiological fraction among the exposed persons (attributable risk) may be a useful tool for apportioning the different causal factors.
We have investigated the relationship between annual decline in forced expiratory volume in one s... more We have investigated the relationship between annual decline in forced expiratory volume in one second (∆FEV 1) and bronchial responsiveness (BR) in aluminium potroom workers. BR was measured in a cross-sectional study of 337 aluminium potroom workers halfway through a 6 yr follow-up study of lung function. A skin-prick test (SPT) was also performed. During follow-up the mean number of measurements of lung function (FEV 1) in each subject was 6.8. Mean ∆FEV 1 was 21.3 ml•yr-1 (within subject SD=30.5 ml•yr-1). Mean ∆FEV 1 was 57.0, 44.5 and 16.6 ml•yr-1 in subjects who had provocative concentration producing a 20% fall in FEV 1 (PC 20) ≤8.0, 8.1-32.0 and >32.0 mg•ml-1 , respectively. After adjustment for gender, atopy, smoking habit, FEV 1 , age and familial asthma the association between BR and ∆FEV 1 was weakened, and was not statistically significant. A significantly accelerated decline in FEV 1 with age was found. The difference in ∆FEV 1 between smokers and nonsmokers was 39.3 ml•yr-1 , and between subjects who had a positive skin-prick test compared to subjects with a negative skin-prick test 39.6 ml•yr-1. In subjects reporting work-related asthmatic symptoms the decline in FEV 1 was 43.2 ml•yr-1 greater than in asymptomatic subjects. In asymptomatic subjects, positive skin-prick test was also associated with increased ∆FEV 1. These data indicate that a single measurement of BR is not a predictor of ∆FEV 1 in aluminium potroom workers. Smoking, work-related asthmatic symptoms, and positive reaction to skin-prick test in asymptomatic workers were risk factors of increased ∆FEV 1 .
We studied pulmonary and auditory function in a cross-sectional study of 26 experienced construct... more We studied pulmonary and auditory function in a cross-sectional study of 26 experienced construction divers compared with 26 workshop workers matched for age, height, and smoking habits. The divers used air as breathing gas and performed open-sea bounce dives to a maximum of 50 m in sea water. The mean number of dives over a mean diving period of 20 yr (SD = 11) was 4746 (SD = 4743) (Range: 450-17000). Assessment of lung function included dynamic lung volume and flow and diffusion capacity (transfer factor) for carbon monoxide (TlCO). The auditory examination was performed measuring air conduction thresholds in a cabin. The results show a significantly higher mean forced vital capacity (FVC) of 6.01 L (SD = 0.88) in the divers compared with 5.67 L (SD = 0.84) (p = 0.045) in the controls, and an alveolar volume (VA) of 7.74 L (SD = 0.99) in the divers compared with 7.35 L (SD = 0.74) (p = 0.035) in the controls. There was a nonsignificant reduction in forced mid-expiratory flow rate (FEF25-75%) and a significant reduction in forced expiratory flow rate at 50% of FVC (FEF50%) among the divers of 4.69 L (SD = 1.41) compared with 5.76 L (SD = 2.03) among the controls of (p = 0.03). There were no differences in FEV1 and TlCO between the two groups. The divers showed reduced auditory function in their left ear compared with their right ear in the 3 kHz (p = 0.006) and 8 kHz (p = 0.022) area. No statistical difference was found in hearing thresholds of the divers compared with those of the controls. Our results indicate that exposure to diving may be associated with changes in pulmonary function and that the left ear may be more vulnerable than the right ear to hearing impairment in construction divers.
The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working grou... more The Norwegian Societies of Thoracic Medicine and Occupational Medicine established a working group to standardise diagnostic procedures and evaluation of work-related respiratory disorders. In cases of suspected work-related diseases the physician may be asked by the National Insurance Administration or an insurance company to make a statement which will be one of the documents used to decide the patient's right to compensation benefit. We discuss the role of the physician as an independent expert. This is different from his role as clinician. The statement should include a balanced presentation of information from different sources, including health and occupational history, and the employer's information about the work environment (quantitative and qualitative exposure data). The statement must also include the results of a clinical examination and an assessment of functional status based on objective tests. The paper contains recommendations for evaluation of permanent impairment in light of the present Norwegian laws and regulations.
Scandinavian Journal of Clinical & Laboratory Investigation, 2000
There is need for relevant markers of bronchial inflammation in epidemiologic studies of asthma. ... more There is need for relevant markers of bronchial inflammation in epidemiologic studies of asthma. Serum eosinophil cationic protein (ECP) is a marker of eosinophil inflammation and asthma activity. We have studied serum ECP in atopic farmers with current asthma, in non-atopic asthmatics and in non-asthmatic, non-atopic controls. In a cross-sectional study of a representative sample of 8,482 farmers in Norway, asthma was recorded using a self-administered questionnaire; spirometry and serum sampling were performed on all of them. Atopy was screened with Phadiatop and RAST analyses to the mites Lepidoglyphus destructor and Tyrophagus putrescentiae in all asthma cases and controls. All the identified atopics had additional RAST analyses on a set of allergens. Serum ECP was tested in 60 persons with current asthma and atopy (mean 16.2, 95% CI 13.2-19.3), 127 non-atopic asthmatics (mean 9.1, 95% CI 8.0-10.2) and 39 non-atopic controls (mean 5.5, 95% CI 4.0 7.0). ECP levels in atopic asthmatics were associated with number of positive allergens and reduction of FEVI values. Moreover, the ECP levels were elevated with allergy to swine, cow, D. pteronyssinus, L. destructor, A. siro, T. putrescentiae, timothy grass and the cereal grains: wheat, oat, barley and rye. Serum ECP seems feasible as an indicator of inflammatory activity in epidemiological studies of current allergic asthma, and may help to indicate the importance of specific allergens. Although the ECP values were significantly more elevated in atopic than in non-atopic asthma, elevated serum ECP was not specific for atopic asthma.
Scandinavian Journal of Work, Environment & Health, Oct 1, 1997
Objectives This study examined ~nortality froin noninalignant respiratory diseases among ferroall... more Objectives This study examined ~nortality froin noninalignant respiratory diseases among ferroalloy workers. Methods The cohort comprised 14 730 men employed for the first time in 1933-1990 and for at least 6 months in 1 of 12 plants. The duration of work in specific departments and exposure to amorphous silica in the ferrosiliconlsilicon-metal (FeSiISi-met) plants, estimated from a job-exposure matrix, were the main exposure variables. Deaths were observed during 1962-1990. The n~ortality was analyzed with the use of standardized mortality ratios (SMR) and internal comparisons of rates. Results Overall mortality from nonrnalignant respiratory diseases was not increased, but mortality from bronchitis, eillphyseina, and asthma combined was significantly increased among the men with at least 3 years of FeSiISi-met furnace work (SMR 1.82, 16 deaths). A Poisson regression analysis of the mortality from these causes among 6359 employees in the FeSiISi-met plants showed a significant increase of 0.06 per unit of amorphous silica exposure observed 10-20 years after the exposure. Six men died of pneumonia while still employed in a ferroinanganeselsilicomanganese (FeMnISiMn) plant. No corresponding deaths occurred among employees in FeSiISi-met plants. Only 2 deaths from pne~unoconiosis were observed in the total cohort. ~o~C~U S~O I I S Among employees in FeSiISi-met plants increased mortality from bronchitis, emphysema, and asthma nay be associated with previous exposure to an~orphous silica. Deaths from pneumonia among FeMnI SiMn workers may be associated with manganese exposure.
Sammendrag: Bakgrunn Akrylamidholdige tetningsmidler (Rhoca-Gil/Siprogel) har vært brukt i en rek... more Sammendrag: Bakgrunn Akrylamidholdige tetningsmidler (Rhoca-Gil/Siprogel) har vært brukt i en rekke større tunnelprosjekter i Norge sent på 1980-tallet og tidlig på 1990-tallet. I forbindelse med rapportering av mulige helseskader på grunn av akrylamideksponering i Romeriksporten høsten 1997, ble det reist spørsmål om andre tunnelarbeidere også kunne ha pådratt seg helseskader etter bruk av akrylamidholdige tetningsstoffer. Metode Vi har undersøkt effekter på nervesystemet, og andre helseeffekter hos 50 tunnelarbeidere tidligere eksponert for akrylamid og N-methylolakrylamid under tunnelarbeid. Femti tunnelarbeidere som ikke hadde arbeidet med akrylamidholdige tetningsstoffer var kontrollgruppe. De besvarte spørreskjema om symptomer og eksponering, gjennomgikk nevropsykologisk undersøkelse, fikk målt nerveledningshastighet i armer og ben, fargesyn og synsfelt, samt visuelt utløste responser (VEP) og elektroretinografi (ERG). Resultater De eksponerte arbeiderne rapporterte økt forekomst av symptomer sammenlignet med kontrollgruppen. Nevropsykologisk undersøkelse avdekket ingen gruppeforskjeller. Neurografi viste få forskjeller mellom gruppene. Det var imidlertid signifikant reduksjon i sensorisk nerveledningshastighet i n.suralis, og hos flere av de eksponerte lot sensorisk svarpotensial seg ikke fremkalle i denne nerven. Ved testing av fargesyn var eksponert gruppe litt svakere til å sortere blånyanser, samtidig som amplitudene ved elektroretinografi ved fotoptisk (30 Hz) stimulering var lett, men ikke statistisk signifikant redusert sammenlignet med kontrollgruppen. Ved synsfeltundersøkelse var terskel for å se enkle stimuli signifikant høyere i sentralt i synsfeltet hos de eksponerte enn hos kontrollene. I tillegg var det samlet sett tegn til en signifikant høyere terskel for å se lysstimuli i en ring ca. 20 ut til siden fra fovea. Konklusjon Resultatene indikerer en mulig lett vedvarende redusert sensorisk nerveledningshastighet i suralisnerven i bena hos de akrylamideksponerte tunnelarbeiderne sammenlignet med kontrollgruppen. En lett svekket fargediskrimineringsevne for blåtoner, samt svekket lyssensitivitet i fovea kan indikere lett vedvarende affeksjon av fotoreseptorer (tapper) sentralt i retina (fovea), noe som også understøttes ved lette forandringer ved elektroretinografi.
Occupational and Environmental Medicine, Aug 1, 1996
Objectives-Concern about the health hazards of exposure to workers in the ferroalloy industry has... more Objectives-Concern about the health hazards of exposure to workers in the ferroalloy industry has initiated this historical cohort study. The aim was to examine the mortality pattern among male employees in 12 Norwegian ferroalloy plants. Methods-All men employed for at least six months who started their first employment during 1933-91 were eligible for the cohort. Deaths observed during 1962-90 were compared with expected figures calculated from national mortalities. Internal comparisons of rates were performed by Poisson regression analysis. The final cohort comprised 14 730 male employees who were observed for 288 886 person-years. Results-Mortality from all causes of death was slightly increased (3390 deaths, standardised mortality ratio (SMR) 1-08, 95% confidence interval (95% CI) 1.04-1.11). Regression analysis of total mortality showed a significant negative trend for the rate ratios with increasing duration of employment. An increased mortality was found among employees in urban plants compared with employees in rural plants (rate ratio (RR) 1-21, 95% CI 1.13-1.29). Excess deaths from cancer (SMR 1 11) and sudden death (SMR 1.47) were found among employees with at least three years of employment. Mortality from accidents, poisonings, and violence was increased among all employees (SMR 1*28). Excess deaths from this cause were however only found for the time after the end of employment in this industry and not during employment (SMR 0.90). Conclusions-The increased mortality from cancer and sudden death could be related to work exposures, at least in subgroups, and these results warrant further studies. The excess deaths from accidents, poisonings, and violence were probably not related to work exposures. The mortality results for short term workers and other information indicate that systematic errors contribute to the increased overall mortality.
Occupational and Environmental Medicine, Aug 1, 1993
A cross sectional study of aspects of their neurology was carried out on 77 chloralkali workers p... more A cross sectional study of aspects of their neurology was carried out on 77 chloralkali workers previously exposed to mercury (Hg) vapour and compared with 53 age matched referents. The chloralkali workers had been exposed for an average of 7 9 years at a con
Occupational and Environmental Medicine, Sep 1, 2002
Aims: To analyse longitudinal changes in pulmonary function in professional divers and their rela... more Aims: To analyse longitudinal changes in pulmonary function in professional divers and their relation with cumulative diving exposure. Methods: The study included 87 men at the start of their education as professional divers. At follow up one, three, and six years later, 83, 81, and 77 divers were reexamined. The median number of compressed air dives in the 77 divers over the follow up period was 196 (range 37-2000). A group of non-smoking policemen (n = 64) were subjected to follow up examinations in parallel with the divers. Assessment of lung function included dynamic lung volumes, maximal expiratory flow rates, and transfer factor for carbon monoxide (Tl CO). The individual rates of change of the lung function variables were calculated by fitting linear regression lines to the data, expressed as percent change per year. Results: The annual reductions in forced vital capacity (FVC) and forced expired volume in one second (FEV 1) were 0.91 (SD 1.22) and 0.84 (SD 1.28) per cent per year in divers, which were significantly higher than the reductions in the policemen of 0.24 (SD 1.04) and 0.16 (SD 1.07) per cent per year (p < 0.001). The annual reduction in the maximal expiratory flow rates at 25% and 75% of FVC expired (FEF 25% and FEF 75%) were related to the log 10 transformed cumulative number of dives in a multiple regression analysis (p < 0.05). The annual reductions in Tl CO were 1.33 (SD 1.85) and 0.43 (SD 1.53) per cent per year in divers and policemen (p < 0.05). Conclusions: FVC, FEV 1 , maximal expiratory flow rates, and Tl CO were significantly reduced in divers over the follow up period when compared with policemen. The contrasts within and between groups suggest that diving has contributed to the reduction in lung function.
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