Jonas Brisman

Adult-onset asthma is associated with self-reported mold or environmental tobacco smoke exposures in the home

Background: In recent years, we have gained better knowledge about the influence of indoor environments on respiratory symptoms and asthma. The purpose of this study was to examine certain exposures in the home environment and the risk of adult‐onset asthma.

Baker's asthma

Bakers asthma is one of the most common forms of occupational asthma. The increasing knowledge in exposure–response relations accumulated in recent years is important in the understanding of bakers asthma. This development has made scientifically based prevention feasible today and bakers asthma should not be regarded as an inevitable occurrence any more. In 1700 Bernardo Ramazzini described respiratory symptoms among bakers caused by exposure to flour dust. However, there are anecdotal references from antiquity describing how Roman slaves working in bakeries protected themselves by using cloth as a primitive respirator to cover their faces because their breathing suffered from inhaling flour. Case reports from the beginning of the 20th century established the concept of bakers asthma as an allergic disease because of the observed combination of positive skin tests to flour extracts and respiratory symptoms suggestive of asthma. The aetiological role of sensitisation to flour in these cases was confirmed by bronchial challenge tests. Rhinitis is very common and usually precedes asthma. Conjunctivitis and skin symptoms may also occur. The baker is often atopic by skin or IgE tests. Symptoms develop after a latency period of months or years, even decades. Initially there is often a clear temporal relation between symptoms and periods of bakery work. Over time, respiratory symptoms may cease to resolve during time off from the bakery. Sensitisation to flour is traditionally often regarded as a prerequisite for the diagnosis of bakers asthma. Although the prognosis of bakers asthma is not reported in the literature, it is usually presumed that symptoms resolve if exposure to offending allergens is stopped. From the 1930s onward there was a number of cross sectional studies surveying populations of bakers, unfortunately many of them uncontrolled—that is, without comparing the bakers with controls. These studies varied considerably in the description of symptoms, and …

Exposure-response relations for self reported asthma and rhinitis in bakers

OBJECTIVES To explore relations between two estimates of exposure to inhalable flour dust, and the incidence rates (IRs) of asthma and rhinitis in bakers. METHODS This was a retrospective cohort study among 2923 bakers. A posted questionnaire registered the disease and work history. For every year, each baker was assigned an estimate of the exposure concentration to inhalable flour dust derived from reported job-tasks and dust measurements. Exposure at onset of disease was expressed as current dust exposure concentration, and as cumulative dose of exposure to dust. A multiple Poisson regression analysis assessed the impacts of the exposure estimates on the IRs of asthma and rhinitis. RESULTS IRs of asthma and rhinitis increased by dust concentration at onset of disease. The IR of asthma for the bakers with highest exposure (dough makers) was 7.3/1000 person-years in men and 6.5 in women and for rhinitis 43.4 and 38.5, respectively. There was a significant association between the dust concentration at onset of disease and the risk for asthma or rhinitis, but not of the cumulative exposure. CONCLUSION The risk of asthma seemed to be increased at inhalable dust concentrations ⩾3 mg/m3 (dough making or bread forming), whereas the risk of rhinitis was increased at all concentrations ⩾1 mg/m3, indicating an increased risk in all bakery job-tasks. The risks seemed to be less dependent on the cumulative exposure dust than the inhalable dust concentrations.

Incidence of asthma in female Swedish hairdressers

Objective: To investigate the risk of asthma in hairdressers. Methods: The incidence of asthma was retrospectively estimated in a Swedish nationwide study including all female hairdressers certified from vocational schools from 1970 to 1995, and a stratified sample of women from the general population were referents. A postal questionnaire included questions on respiratory tract symptoms, atopy, smoking, working periods as a hairdresser, and number of specific hair treatments performed/week. Reported exposures were validated by occupational hygienists. Rate ratios of incidence (IRRs) of asthma were estimated by Poisson regression, adjusted for calendar year of observation, hay fever, smoking, and region of domicile. Results: The crude incidences of asthma/1000 person-years were: 3.9 during active years as a hairdresser, 2.8 among the hairdressers when not working in the profession, and 3.1 among the referents. The corresponding IRR for being an active hairdresser compared with the referents was 1.3 (95% confidence interval (95% CI) 1.0 to 1.6). Moderate effects on risk of asthma were found both from hairdressing work (IRR=1.6 (1.1 to 2.2) among never-smokers) and from smoking (IRR=1.6 (1.2 to 2.2) among referents). However, the combined effect from hairdressing work and smoking (IRR=1.5 (1.0 to 2.1)) was less than expected (p=0.02). No effect modification by respiratory atopy was found. The hairdressers most often performing hair bleaching treatments (IRR=1.5 (0.7 to 3.0)) or using hair spray (IRR=1.4 (0.8 to 2.4)) had, compared with the most infrequent users, a slightly, but not significantly higher incidence of asthma. Exposure to persulphates in hair bleach was estimated to be 0.04–0.15 mg/m3 during mixing of the powder. Reported average number of bleaching treatments agreed well with those performed according to a diary. Conclusions: Active hairdressing work was associated with a moderately increased incidence of asthma among lifelong non-smokers. The results are moderately supportive, but not conclusive, of associations between asthma and exposure to hair bleach or hair spray.

Incidence of hand eczema in female Swedish hairdressers

Objective: To estimate the occurrence of hand eczema in hairdressers in Sweden. Methods: The occurrence of hand eczema was estimated in a Swedish longitudinal retrospective cohort study including all female graduates from vocational schools for hairdressers from 1970 to 1995. A stratified sample from the general population acted as controls. A self-administered questionnaire including questions on the occurrence of hand eczema, skin atopy, working periods and number of hair treatments performed per week was sent to the participants. Incidence rate ratios (IRRs) of hand eczema were estimated. Results: The incidence rate of hand eczema in hairdressers was 23.8 cases/1000 person-years, whereas in hairdressers who were aged <25 years it was 37.1/1000 person-years. The corresponding IRR for hairdressers compared with controls was 2.5 (95% confidence interval (CI) 2.2 to 2.8), and that for younger hairdressers was 3.1 (95% CI 2.6 to 3.5). The mean age at onset of hand eczema was 21.6 years for hairdressers and 21.2 years for controls. The 1-year prevalence of hand eczema was 18.0% for hairdressers and 12.1% for controls. A large number of hair treatments involving exposure to skin irritants and sensitisers were reported. The incidence rate of hand eczema was higher among individuals with a history of childhood eczema, both for hairdressers and for controls, giving an (age-adjusted) IRR of 1.9 and 2.2, respectively. The attributable fraction of hand eczema from skin atopy was 9.6%. A synergistic effect of skin atopy and hairdressing was found on the occurrence of hand eczema. The relative excess risk due to interaction was 1.21 (95% CI 0.21 to 2.21; p = 0.01). Conclusion: Hairdressers are highly exposed to skin-damaging substances. The self-reported incidence of hand eczema was substantially higher in female hairdressers than in controls from the general population and than that found previously in register-based studies. For many individuals, onset of hand eczema occurs early in life. Only about 10% of the hand eczema cases among hairdressers would be prevented if no one with skin atopy entered the trade.

Fish intake of Swedish male adolescents is a predictor of cognitive performance

Aim: Fish intake is reported to positively influence cognitive performance in infants and the elderly. In a longitudinal cohort study, we evaluated how fish consumption related to later cognitive performance in healthy young male adolescents.

Occurrence of self reported hand eczema in Swedish bakers.

OBJECTIVES: To estimate the risk of bakers developing hand eczema. The importance of atopy was studied as well as change of job due to hand eczema. METHODS: A retrospective cohort study was performed among bakers trained in Swedish trade schools in 1961-89 (n = 2923). School referents followed other programmes (n = 1258); population controls were randomly selected from the general population (n = 1258). A questionnaire on self reported hand eczema, year of onset of hand eczema, change of work due to hand eczema, childhood eczema, family atopy, and work history was posted to all participants. RESULTS: The incidence of hand eczema among male controls was 4.4-5.4 cases/1,000 person-years compared with 16.7 for bakery work. The corresponding figures for women were 11.3-14.1 compared with 34.4. The relative risk for male bakers was 3.5 (95% confidence interval (95% CI) 2.8 to 4.5) and for female bakers 2.8 (2.2 to 3.6). Skin atopy increased the incidence about threefold and a synergistic effect of atopy and exposure was indicated. Also, bakers had changed job significantly more often than controls. CONCLUSIONS: Swedish bakers, mainly working during the 1970s and 1980s, have about a threefold increased risk of hand eczema. There seems to be a synergistic effect of atopy and occupational exposure.

Fish consumption and school grades in Swedish adolescents: a study of the large general population

Aim:  To study the associations between fish intake and academic achievement as cognitive parameter among Swedish adolescents.

Does tobacco smoking influence the occurrence of hand eczema

Background  Tobacco smoking is known to influence various inflammatory skin diseases and an association between tobacco smoking and hand eczema has been proposed in some studies.

Asbestos associated tumours in car mechanics.

Asbestos in brake linings and clutches is considered to be a major source of asbestos exposure to the general public. Nevertheless, the asbestos exposure to the car mechanics from this source during repair of brakes and clutches is several times higher. It has been suspected that the exposure may cause lung cancer or mesothelioma in car mechanics and the union asked for an investigation. To study this subject we used linkages between the census of 1960 in Sweden and the Swedish Cancer Register and the Swedish Death Register respectively. This is a report on the preliminary findings.