Linnea Lillienberg - Academia.edu (original) (raw)

Papers by Linnea Lillienberg

Occupational and Environmental Medicine, 2007

Occupational and Environmental Medicine, Apr 12, 2018

Aging and chronic diseases. Epidemiological and public health approaches.

Occupational and Environmental Medicine, 2016

The burden of occupational asthma is underestimated partly due to the lack of knowledge regarding... more The burden of occupational asthma is underestimated partly due to the lack of knowledge regarding asthmagen exposures. To study work-related asthma in population-based cohorts, improvement of exposure assessment is crucial. An asthma-specific Job-Exposure Matrix (JEM) was developed at the end of the 1990s (Kennedy SM et al, 2000;http://asthmajem.vjf.inserm.fr/;ISCO-88 system). An update of the JEM is necessary since the number of suspected asthmagens has tripled since 2000. For this update, evaluation of exposure to 8 broad groups and 33 specific asthmagens, including 11 newly recognised, were classified into three categories: high (high probability of exposure and moderate-to-high intensity), medium (low-to-moderate probability or low intensity), no (unlikely to be exposed). A working group of three experts was assigned for each asthmagen. Important methodological aspects were kept in mind during the process: (1) within a working group, experts evaluated exposures independently from each other. Cohen’s Kappa’s were calculated to estimate initial agreement. If expert assessments were inconsistent the final decision was taken by consensus. (2) specificity was favoured over sensitivity, i.e. jobs were classified with high exposure only if the probability of exposure was high and the intensity moderate-to-high. Initial agreement between the three experts was mostly fair-to-moderate (0.2–0.5). Out of 506 jobs, 82.4% (organic solvents) to 99.8% (persulfates) were classified as non-exposed and 0% (enzymes) to 2.5% (organic solvents) as highly-exposed. The final steps in progress include review of assigned exposures by all experts and improvement of a two-step expert re-evaluation after application of the JEM (checking ISCO code and exposure assessment for selected jobs). The JEM will soon be available for ISCO-88 and is foreseen for other classifications (ISCO-68;ISCO-08;PCS-2003). This new Asthma-specific JEM will enable improved evaluations of associations between occupational exposures and asthma phenotypes in epidemiological studies and determination of the burden of disease due to occupational asthmagens. Grant: PHC Van-Gogh

PubMed, 1984

Cerebrospinal fluid (CSF) was obtained from 17 men occupationally exposed to organic solvents and... more Cerebrospinal fluid (CSF) was obtained from 17 men occupationally exposed to organic solvents and diagnosed as having a psycho-organic syndrome. Healthy volunteers and patients without neurological disorders were used as controls. The albumin ratio was increased in three heavily exposed men, indicating an increased passage of albumin over the blood-brain barrier. A slight monocytoid reaction was present in three of the subjects in the exposed group. Myelin basic protein and enolase activity were within normal limits. Isoelectric focusing of CSF-enriched proteins obtained by absorption chromatography showed alterations in nine out of 17 exposed individuals: The most prominent change was a relative increase of the protein band with Ip 4.7.

Scandinavian Journal of Work, Environment & Health, Oct 1, 1999

Objectives This study examined certain occupational exposures and the risk for adult-onset asthma... more Objectives This study examined certain occupational exposures and the risk for adult-onset asthma. Methods A nested case-referent study of adult-onset asthma was performed on a random population sample (N=15 813), aged 21 to 5 1 years. Cases for the study included 2 groups: subjects reporting "physician-diagnosed" asthma (N=251) and a broader "asthma" group (N=362). The "asthma" group consisted of subjects with "physician-diagnosed" asthma (N=251) and subjects reporting asthma-like symptoms without having "physician-diagnosed" asthma (N=l 1 I). The referents (N=2044) were randomly selected from the whole population sample. The case-referent sample was investigated with a comprehensive questionnaire about occupational exposures, asthma, respiratory symptoms, smoking, and atopy. Odds ratios were calculated with stratification for gender, year of diagnosis, and birth year. Results The highest odds ratio for "physician-diagnosed" asthma was associated with exposure to flour dust [odds ratio (OR) 2.8,95% confidence interval (95% CI) 1.5-5.21 and the occupational handling of resin-based paints (isocyanates) (OR 3.0,95% CI 1.6-5.9). Exposure to welding fumes, textile dust, and work with glues containing acrylates was also associated with an increased odds ratio for "physician-diagnosed" asthma. Including persons with asthma-like symptoms (ie, the asthma group) showed similar results. C O~C~U S~O~ This population-based case-referent study from Sweden indicates that occupational exposure to aciylate-based compounds and welding fumes is associated with increased risk for adult-onset asthma.

PubMed, May 1, 1981

The cancer morbidity pattern among 788 men with at least five years' exposure to oil mist was inv... more The cancer morbidity pattern among 788 men with at least five years' exposure to oil mist was investigated. Based on measurements, interviews of workers and a survey of changes over the years, the average exposure level was estimated to have been 5 mg/m3 or more prior to 1965. Exclusive of cancer of the scrotum, there were 39 observed cases of cancer compared to 52.9 expected. There were four cases of cancer of the scrotum among the turners but none among the grinders. Three cases of lung cancer were found, compared to 5.4 expected. Among the grinders there was a doubled, but not statistically significant, increase in cancer of the stomach. The mortality from all causes showed a so-called "healthy worker effect," that is, 126 deaths compared to 154.3 expected.

30th International Congress on Occupational Health (March 18-23, 2012), Mar 21, 2012

Annals of Occupational Hygiene, Sep 1, 2000

The aim of the study was to compare four different immunological methods to analyse fungal aamyla... more The aim of the study was to compare four different immunological methods to analyse fungal aamylase in flour dust samples. Three European research groups have independently developed four immuno assay based methods to measure a-amylase in air samples. Three of the methods use polyclonal antibodies and one method uses monoclonal antibodies. Eighty personal samples have been collected during two to three work-shifts in four bakeries. Sampling was performed with PAS-6 inhalable dust samplers and aliquots from each sample were analysed by the three laboratories. The agreement between the four methods was high compared with agreement between immunological methods to measure other allergens in the air, e.g. for rat allergens. For the three methods with polyclonal antibodies the mean differences for individual samples was less than a factor of two. The arithmetic means (AM) of the estimated a-amylase exposure were 12.5, 11.3, 8.6 and 25.9 ng/m 3 for the respective methods with values ranging from below the detection limit to 192, 215, 207 and 615 ng/m 3. The AM for all samples analysed by the methods with polyclonal antibodies varied by about a factor of 1.5. About one-third of the values were below or at the detection limit for all methods. In a regression analysis the squared correlation coefficients (R 2) between the methods varied between 0.91 and 0.95 for the log transformed values. For workplace monitoring, results from the methods using polyclonal antibodies will be relatively comparable. High levels of a-amylase might differ in absolute numbers with a factor of two or more between the different methods but will anyway be considered as high and should result in preventive actions. On the other hand, this study also shows that despite the relative agreement between methods, there is a clear need for standardization.

Scandinavian Journal of Work, Environment & Health, Oct 1, 2001

Welding in the World / Le Soudage dans le Monde, 1996

European journal of respiratory diseases. Supplement, 1980

The method is demonstrated in connection with a study of lung cancer among metal-workers exposed ... more The method is demonstrated in connection with a study of lung cancer among metal-workers exposed to oil mist. As exposure to oil mist is uncommon and lung cancer is common, the cohort study is the method of choice. Estimation of exposure, problems of selection, calculation of person-years etc is discussed. There was no increased morbidity from lung cancer.

The Annals of Occupational Hygiene, 1994

Bakery workers are at risk of developing respiratory symptoms, such as asthma and rhinitis. Expos... more Bakery workers are at risk of developing respiratory symptoms, such as asthma and rhinitis. Exposure to inhalable flour dust in 12 Swedish bakeries was therefore determined: concentrations of airborne inhalable flour dust were measured with the IOM personal inspirable dust sampler and the particle size distribution assessed using the IOM personal inspirable aerosol spectrometer, and the fractions of alpha-amylase, water-soluble protein and total protein in flour dust were determined. A total of 129 measurements were performed of which 77 were repeated measurements. There was a clear hierarchy in geometric mean exposure among bakery workers, with in descending order doughmakers (5.46 mg m-3), bread-formers (2.69 mg m-3), oven workers (1.17 mg m-3), and packers and confectionery workers (0.53 mg m-3). The repeated measurements revealed that within each task group there were considerable differences in mean exposure among the workers: this was demonstrated by geometric standard deviations of between-worker variance of 1.63-1.77. Partitioning of the total variability of inhalable flour dust exposure showed that the task group was the principal source of variance, accounting for 61-69% of the total variability. The optimum grouping strategy was independent of whether the oven workers and the packers were assigned to the same or to different task groups. The doughmakers and the bread-formers are two clearly distinguishable exposure groups with largely overlapping exposure distributions. On average, the flour dust contained 9% total protein, 2.3% water-soluble protein and 0.03% alpha-amylase. The inhalable flour dust was characterized by a substantial proportion of particles with a d(ac) above 10 microns. It was estimated that the thoracic subfraction contributed 39% to the total mass of inhalable dust, and the respirable subfraction 19%.

Scandinavian Journal of Work, Environment & Health, 1998

This publication is a result of a cooperation between the authors at Chalmers University of Techn... more This publication is a result of a cooperation between the authors at Chalmers University of Technology and Gothenburg University, i.e. between the Department of Transportation and the Department of Occupational Health and the Department of Sociology.

Science of The Total Environment, 2007

The aim of the study was to determine if occupational exposure to hydrofluorocarbons (HFC) and hy... more The aim of the study was to determine if occupational exposure to hydrofluorocarbons (HFC) and hydrochlorofluorocarbons (HCFC) generates autoimmune responses against CYP2E1. HFCs and HCFCs have replaced the chlorofluorocarbons (CFC) in e.g. refrigeration installations and air-conditioning systems. During the substitution period, refrigeration mechanics reported symptoms like asthma, influenza-like reactions, and joint troubles. These symptoms resemble those of chronic inflammatory diseases with an autoimmune component. Since exposure to structurally similar chemicals, e.g. halothane, has previously been associated with autoimmune responses and diseases, autoimmunity among the refrigeration mechanics might hypothetically explain the reported inflammatory symptoms. Serum from 44 Swedish men, occupationally exposed to halogenated hydrocarbons, was screened for antibodies against CYP2E1 with enzyme-linked immunosorbent assay. Thirty of the workers had asthma, joint problems or influenza-like symptoms whereas 14 of them had no such symptoms. They were all selected from a cohort of 280 refrigeration mechanics. Unexposed, healthy, Swedish men (n=35) constituted control group. The study was approved by the Ethics Committee at Karolinska Institutet. No increase in autoantibodies against CYP2E1 was detected among the occupationally exposed workers as compared to the unexposed controls. Further, there was no difference in antibody titer between the exposed workers with symptoms and the exposed, asymtomatic workers or the unexposed controls. The present study does not completely exclude a connection between exposure and effect but makes the relation less likely at these exposure levels.

Occupational and Environmental Medicine, 2007

Atmospheric Environment, 2004

The follow-up of cohorts of adults from more than 20 European centres of the former ECRHS I (1989... more The follow-up of cohorts of adults from more than 20 European centres of the former ECRHS I (1989-1992) investigates long-term effects of exposure to ambient air pollution on respiratory health, in particular asthma and change of pulmonary function. Since PM 2.5 is not routinely monitored in Europe, we measured PM 2.5 concentrations in 21 participating centres to estimate 'background' exposure in these cities. Winter (November-February), summer (May-August) and annual mean (all months) values of PM 2.5 were determined from measuring periods between June 2000 and November 2001. Sampling was conducted for 7 days per month for a year. Annual and winter mean concentrations of PM 2.5 vary substantially being lowest in Iceland and highest in centres in Northern Italy. Annual mean concentrations ranged from 3.7 to 44.9 mg m À3 , winter mean concentrations from 4.8 to 69.2 mg m À3 , and summer mean concentrations from 3.3 to 23.1 mg m À3. Seasonal variability occurred but did not follow the same pattern across all centres. Therefore, ranking of centres varied from summer to winter. Simultaneously, NO 2 concentrations were measured using passive sampling tubes. Annual mean NO 2 concentrations range from 4.9 to 72.1 mg m À3 with similar seasonal variations across centres and constant ranking of centres between seasons. The correlation between annual

Scandinavian Journal of Work, Environment and Health, 2006

The study investigated whether working as a hairdresser has a negative impact on fertility, measu... more The study investigated whether working as a hairdresser has a negative impact on fertility, measured as time to pregnancy and miscarriage risk. Self-administered questionnaires were sent to 5289 Swedish hairdressers (response rate 50%) and to 5299 age-matched women from the general Swedish population (response rate 54%). Information was collected on time to pregnancy or trying time for women who had tried, but failed, to conceive at the time of the study. The outcome of the pregnancy was determined and categorized as either miscarriage or stillbirth or live birth. The hairdressers were compared with the referents with respect to these two outcomes. Within the hairdresser cohort, the effects of hair treatments, as well as physical workload and stress were investigated. The hairdressers were less successful than the reference cohort in conceiving (fecundability ratio 0.91, 95% confidence interval 0.83-0.99). The effect was reduced after first-month conceptions were excluded, the indic...

Occupational and Environmental Medicine, 2007

Occupational and Environmental Medicine, Apr 12, 2018

Aging and chronic diseases. Epidemiological and public health approaches.

Occupational and Environmental Medicine, 2016

The burden of occupational asthma is underestimated partly due to the lack of knowledge regarding... more The burden of occupational asthma is underestimated partly due to the lack of knowledge regarding asthmagen exposures. To study work-related asthma in population-based cohorts, improvement of exposure assessment is crucial. An asthma-specific Job-Exposure Matrix (JEM) was developed at the end of the 1990s (Kennedy SM et al, 2000;http://asthmajem.vjf.inserm.fr/;ISCO-88 system). An update of the JEM is necessary since the number of suspected asthmagens has tripled since 2000. For this update, evaluation of exposure to 8 broad groups and 33 specific asthmagens, including 11 newly recognised, were classified into three categories: high (high probability of exposure and moderate-to-high intensity), medium (low-to-moderate probability or low intensity), no (unlikely to be exposed). A working group of three experts was assigned for each asthmagen. Important methodological aspects were kept in mind during the process: (1) within a working group, experts evaluated exposures independently from each other. Cohen’s Kappa’s were calculated to estimate initial agreement. If expert assessments were inconsistent the final decision was taken by consensus. (2) specificity was favoured over sensitivity, i.e. jobs were classified with high exposure only if the probability of exposure was high and the intensity moderate-to-high. Initial agreement between the three experts was mostly fair-to-moderate (0.2–0.5). Out of 506 jobs, 82.4% (organic solvents) to 99.8% (persulfates) were classified as non-exposed and 0% (enzymes) to 2.5% (organic solvents) as highly-exposed. The final steps in progress include review of assigned exposures by all experts and improvement of a two-step expert re-evaluation after application of the JEM (checking ISCO code and exposure assessment for selected jobs). The JEM will soon be available for ISCO-88 and is foreseen for other classifications (ISCO-68;ISCO-08;PCS-2003). This new Asthma-specific JEM will enable improved evaluations of associations between occupational exposures and asthma phenotypes in epidemiological studies and determination of the burden of disease due to occupational asthmagens. Grant: PHC Van-Gogh

PubMed, 1984

Cerebrospinal fluid (CSF) was obtained from 17 men occupationally exposed to organic solvents and... more Cerebrospinal fluid (CSF) was obtained from 17 men occupationally exposed to organic solvents and diagnosed as having a psycho-organic syndrome. Healthy volunteers and patients without neurological disorders were used as controls. The albumin ratio was increased in three heavily exposed men, indicating an increased passage of albumin over the blood-brain barrier. A slight monocytoid reaction was present in three of the subjects in the exposed group. Myelin basic protein and enolase activity were within normal limits. Isoelectric focusing of CSF-enriched proteins obtained by absorption chromatography showed alterations in nine out of 17 exposed individuals: The most prominent change was a relative increase of the protein band with Ip 4.7.

Scandinavian Journal of Work, Environment & Health, Oct 1, 1999

Objectives This study examined certain occupational exposures and the risk for adult-onset asthma... more Objectives This study examined certain occupational exposures and the risk for adult-onset asthma. Methods A nested case-referent study of adult-onset asthma was performed on a random population sample (N=15 813), aged 21 to 5 1 years. Cases for the study included 2 groups: subjects reporting "physician-diagnosed" asthma (N=251) and a broader "asthma" group (N=362). The "asthma" group consisted of subjects with "physician-diagnosed" asthma (N=251) and subjects reporting asthma-like symptoms without having "physician-diagnosed" asthma (N=l 1 I). The referents (N=2044) were randomly selected from the whole population sample. The case-referent sample was investigated with a comprehensive questionnaire about occupational exposures, asthma, respiratory symptoms, smoking, and atopy. Odds ratios were calculated with stratification for gender, year of diagnosis, and birth year. Results The highest odds ratio for "physician-diagnosed" asthma was associated with exposure to flour dust [odds ratio (OR) 2.8,95% confidence interval (95% CI) 1.5-5.21 and the occupational handling of resin-based paints (isocyanates) (OR 3.0,95% CI 1.6-5.9). Exposure to welding fumes, textile dust, and work with glues containing acrylates was also associated with an increased odds ratio for "physician-diagnosed" asthma. Including persons with asthma-like symptoms (ie, the asthma group) showed similar results. C O~C~U S~O~ This population-based case-referent study from Sweden indicates that occupational exposure to aciylate-based compounds and welding fumes is associated with increased risk for adult-onset asthma.

PubMed, May 1, 1981

The cancer morbidity pattern among 788 men with at least five years' exposure to oil mist was inv... more The cancer morbidity pattern among 788 men with at least five years' exposure to oil mist was investigated. Based on measurements, interviews of workers and a survey of changes over the years, the average exposure level was estimated to have been 5 mg/m3 or more prior to 1965. Exclusive of cancer of the scrotum, there were 39 observed cases of cancer compared to 52.9 expected. There were four cases of cancer of the scrotum among the turners but none among the grinders. Three cases of lung cancer were found, compared to 5.4 expected. Among the grinders there was a doubled, but not statistically significant, increase in cancer of the stomach. The mortality from all causes showed a so-called "healthy worker effect," that is, 126 deaths compared to 154.3 expected.

30th International Congress on Occupational Health (March 18-23, 2012), Mar 21, 2012

Annals of Occupational Hygiene, Sep 1, 2000

The aim of the study was to compare four different immunological methods to analyse fungal aamyla... more The aim of the study was to compare four different immunological methods to analyse fungal aamylase in flour dust samples. Three European research groups have independently developed four immuno assay based methods to measure a-amylase in air samples. Three of the methods use polyclonal antibodies and one method uses monoclonal antibodies. Eighty personal samples have been collected during two to three work-shifts in four bakeries. Sampling was performed with PAS-6 inhalable dust samplers and aliquots from each sample were analysed by the three laboratories. The agreement between the four methods was high compared with agreement between immunological methods to measure other allergens in the air, e.g. for rat allergens. For the three methods with polyclonal antibodies the mean differences for individual samples was less than a factor of two. The arithmetic means (AM) of the estimated a-amylase exposure were 12.5, 11.3, 8.6 and 25.9 ng/m 3 for the respective methods with values ranging from below the detection limit to 192, 215, 207 and 615 ng/m 3. The AM for all samples analysed by the methods with polyclonal antibodies varied by about a factor of 1.5. About one-third of the values were below or at the detection limit for all methods. In a regression analysis the squared correlation coefficients (R 2) between the methods varied between 0.91 and 0.95 for the log transformed values. For workplace monitoring, results from the methods using polyclonal antibodies will be relatively comparable. High levels of a-amylase might differ in absolute numbers with a factor of two or more between the different methods but will anyway be considered as high and should result in preventive actions. On the other hand, this study also shows that despite the relative agreement between methods, there is a clear need for standardization.

Scandinavian Journal of Work, Environment & Health, Oct 1, 2001

Welding in the World / Le Soudage dans le Monde, 1996

European journal of respiratory diseases. Supplement, 1980

The method is demonstrated in connection with a study of lung cancer among metal-workers exposed ... more The method is demonstrated in connection with a study of lung cancer among metal-workers exposed to oil mist. As exposure to oil mist is uncommon and lung cancer is common, the cohort study is the method of choice. Estimation of exposure, problems of selection, calculation of person-years etc is discussed. There was no increased morbidity from lung cancer.

The Annals of Occupational Hygiene, 1994

Bakery workers are at risk of developing respiratory symptoms, such as asthma and rhinitis. Expos... more Bakery workers are at risk of developing respiratory symptoms, such as asthma and rhinitis. Exposure to inhalable flour dust in 12 Swedish bakeries was therefore determined: concentrations of airborne inhalable flour dust were measured with the IOM personal inspirable dust sampler and the particle size distribution assessed using the IOM personal inspirable aerosol spectrometer, and the fractions of alpha-amylase, water-soluble protein and total protein in flour dust were determined. A total of 129 measurements were performed of which 77 were repeated measurements. There was a clear hierarchy in geometric mean exposure among bakery workers, with in descending order doughmakers (5.46 mg m-3), bread-formers (2.69 mg m-3), oven workers (1.17 mg m-3), and packers and confectionery workers (0.53 mg m-3). The repeated measurements revealed that within each task group there were considerable differences in mean exposure among the workers: this was demonstrated by geometric standard deviations of between-worker variance of 1.63-1.77. Partitioning of the total variability of inhalable flour dust exposure showed that the task group was the principal source of variance, accounting for 61-69% of the total variability. The optimum grouping strategy was independent of whether the oven workers and the packers were assigned to the same or to different task groups. The doughmakers and the bread-formers are two clearly distinguishable exposure groups with largely overlapping exposure distributions. On average, the flour dust contained 9% total protein, 2.3% water-soluble protein and 0.03% alpha-amylase. The inhalable flour dust was characterized by a substantial proportion of particles with a d(ac) above 10 microns. It was estimated that the thoracic subfraction contributed 39% to the total mass of inhalable dust, and the respirable subfraction 19%.

Scandinavian Journal of Work, Environment & Health, 1998

This publication is a result of a cooperation between the authors at Chalmers University of Techn... more This publication is a result of a cooperation between the authors at Chalmers University of Technology and Gothenburg University, i.e. between the Department of Transportation and the Department of Occupational Health and the Department of Sociology.

Science of The Total Environment, 2007

The aim of the study was to determine if occupational exposure to hydrofluorocarbons (HFC) and hy... more The aim of the study was to determine if occupational exposure to hydrofluorocarbons (HFC) and hydrochlorofluorocarbons (HCFC) generates autoimmune responses against CYP2E1. HFCs and HCFCs have replaced the chlorofluorocarbons (CFC) in e.g. refrigeration installations and air-conditioning systems. During the substitution period, refrigeration mechanics reported symptoms like asthma, influenza-like reactions, and joint troubles. These symptoms resemble those of chronic inflammatory diseases with an autoimmune component. Since exposure to structurally similar chemicals, e.g. halothane, has previously been associated with autoimmune responses and diseases, autoimmunity among the refrigeration mechanics might hypothetically explain the reported inflammatory symptoms. Serum from 44 Swedish men, occupationally exposed to halogenated hydrocarbons, was screened for antibodies against CYP2E1 with enzyme-linked immunosorbent assay. Thirty of the workers had asthma, joint problems or influenza-like symptoms whereas 14 of them had no such symptoms. They were all selected from a cohort of 280 refrigeration mechanics. Unexposed, healthy, Swedish men (n=35) constituted control group. The study was approved by the Ethics Committee at Karolinska Institutet. No increase in autoantibodies against CYP2E1 was detected among the occupationally exposed workers as compared to the unexposed controls. Further, there was no difference in antibody titer between the exposed workers with symptoms and the exposed, asymtomatic workers or the unexposed controls. The present study does not completely exclude a connection between exposure and effect but makes the relation less likely at these exposure levels.

Occupational and Environmental Medicine, 2007

Atmospheric Environment, 2004

The follow-up of cohorts of adults from more than 20 European centres of the former ECRHS I (1989... more The follow-up of cohorts of adults from more than 20 European centres of the former ECRHS I (1989-1992) investigates long-term effects of exposure to ambient air pollution on respiratory health, in particular asthma and change of pulmonary function. Since PM 2.5 is not routinely monitored in Europe, we measured PM 2.5 concentrations in 21 participating centres to estimate 'background' exposure in these cities. Winter (November-February), summer (May-August) and annual mean (all months) values of PM 2.5 were determined from measuring periods between June 2000 and November 2001. Sampling was conducted for 7 days per month for a year. Annual and winter mean concentrations of PM 2.5 vary substantially being lowest in Iceland and highest in centres in Northern Italy. Annual mean concentrations ranged from 3.7 to 44.9 mg m À3 , winter mean concentrations from 4.8 to 69.2 mg m À3 , and summer mean concentrations from 3.3 to 23.1 mg m À3. Seasonal variability occurred but did not follow the same pattern across all centres. Therefore, ranking of centres varied from summer to winter. Simultaneously, NO 2 concentrations were measured using passive sampling tubes. Annual mean NO 2 concentrations range from 4.9 to 72.1 mg m À3 with similar seasonal variations across centres and constant ranking of centres between seasons. The correlation between annual

Scandinavian Journal of Work, Environment and Health, 2006

The study investigated whether working as a hairdresser has a negative impact on fertility, measu... more The study investigated whether working as a hairdresser has a negative impact on fertility, measured as time to pregnancy and miscarriage risk. Self-administered questionnaires were sent to 5289 Swedish hairdressers (response rate 50%) and to 5299 age-matched women from the general Swedish population (response rate 54%). Information was collected on time to pregnancy or trying time for women who had tried, but failed, to conceive at the time of the study. The outcome of the pregnancy was determined and categorized as either miscarriage or stillbirth or live birth. The hairdressers were compared with the referents with respect to these two outcomes. Within the hairdresser cohort, the effects of hair treatments, as well as physical workload and stress were investigated. The hairdressers were less successful than the reference cohort in conceiving (fecundability ratio 0.91, 95% confidence interval 0.83-0.99). The effect was reduced after first-month conceptions were excluded, the indic...