Apprentice Bakers Research Articles

Do airway inflammation and airway responsiveness markers at the start of apprenticeship predict their evolution during initial training? A longitudinal study among apprentice bakers, pastry makers and hairdressers

BackgroundThe natural history of airway inflammation and symptoms in occupations at risk of asthma is still not fully understood. We aimed to study the evolution during apprenticeship of inflammation markers, bronchial hyperresponsiveness (BHR) and symptoms in at-risk subgroups as defined from measurements of markers made shortly after the start of training.MethodsRespiratory symptoms, FEV1 and airway resistance post-bronchial challenge (MBC) test results, fractional exhaled nitric oxide (FeNO) measurements, and eosinophils in nasal lavage fluid were investigated in apprentice bakers, pastry-makers and hairdressers. Four visits were conducted: at the start of the training and every six months thereafter. Four baseline risk groups were defined, based on, (i) a high level of FeNO (NO), (ii) eosinophils > 1% (Eosino), (iii) a ≥ 15% decrease in FEV1 during the MBC test (HR), and (iv) a ≥ 50% increase in the resistance (Resist). The statistical analysis relied on mixed models.ResultsAt baseline, the inflammation markers were related to the MBC markers. There was no evidence to suggest that the baseline risk groups predict a differential evolution of the airway inflammation and bronchial responsiveness markers, or the asthma-like symptoms considered. The baseline risk groups defined from MBC test predicted the levels of MBC markers. Similarly, the baseline risk groups based on eosinophilic inflammation predicted the levels of markers for eosinophilia. These results were similar in the three training tracks, with the exception of the FeNO levels which were not different according to the Eosino risk group. Twelve possible new asthma cases were identified, only the HR risk group predicted their occurrence.ConclusionsAmong this young population, at-risk groups based on initial high levels of inflammation markers did not experience any worsening during the follow-up. However, initial BHR predicted consistently high levels of all markers considered and occurrence of possible asthma.

A 3-D interactive software tool to help VSEs/SMEs integrate risk prevention in workplace design projects

In workplace design or refit projects, it is recommended to use a global, participative and progressive approach supported by simulation in order to take into account health, safety and working conditions. We propose a modeling tool based on new 3-D interactive computer technologies. To assess the tool’s usefulness, several tests were carried out, in particular two usage-based validations with apprentice bakers. In addition, external technical consultants (architects, equipment designers, etc.) were interviewed. These tests showed that the target population, i.e. VSEs/SMEs acting as occasional clients, were able to easily learn how to use the proposed software. It was also demonstrated that the software made it possible to rapidly model and test layout assumptions, made the project easy to understand and facilitated exchange with external participants. Interviews with external consultants confirmed the tool’s usefulness for workplace design projects.

Exhaled nitric oxide and spirometry in respiratory health surveillance

Exposure to pollutants in bakeries and hairdressing salons can cause airway syndromes varying from bronchial irritation to asthma. Workplace respiratory health surveillance aims to identify possible cases requiring further investigation. To compare the performance of fractional exhaled nitric oxide (FE(NO)) and spirometry for health surveillance of apprentice bakers (ABs) and apprentice hairdressers (AHDs). Determinants of FE(NO) were also identified. Symptoms and physician-diagnosed asthma were evaluated by questionnaire. FE(NO) was measured and spirometry was carried out. Subjects with elevated FE(NO) (FE(NO) > upper limit normal), airway obstruction [forced expiratory volume in 1 s (FEV(1))/forced vital capacity (FVC) < 95th percentile] and atopy (history of allergies) were identified. A total of 126 apprentices (59 ABs and 67 AHDs) participated. Twenty-nine (23%) apprentices had abnormal tests: 4 had associated high FE(NO) and airway obstruction, while 25 had either high FE(NO) (n = 15) or airway obstruction (n = 10) alone. Compared with ABs (n = 16), AHDs (n = 13) had more asthma (38 versus 0%; P < 0.05) and atopy (62 versus 6%; P < 0.05). There was no difference in symptoms, smoking FE(NO) or airways obstruction. Among 97 subjects with normal tests, no differences existed between ABs (n = 53) and AHDs (n = 44). Average FE(NO) was increased in atopic non-smokers compared with atopic smokers and non-atopic subjects (P < 0.05). Smoking, a history of allergies, FEV(1)/FVC % observed and respiratory symptoms were the main determinants of FE(NO). FE(NO) and spirometry were not overlapping dimensions in ABs and hairdressers, each test contributing unique information on the physiological status of the respiratory system. FE(NO) may provide added information on airway inflammation not provided by spirometry.

Allergic asthma after flour inhalation in subjects without occupational exposure to flours: an experimental pilot study

Cross-reactivity between grass pollen and grain flour allergens is well known, but their significance in apprentice bakers with primary sensitization to grass pollen is not known. Twenty-five subjects with mild asthma (most of them with hay fever), but without prior occupational flour exposure, underwent standardized experimental inhalation challenges with placebo and wheat and rye flours in randomized order on three consecutive days. Sensitization to flours and environmental allergens was assessed by skin prick tests and specific IgE antibodies in sera. IgE inhibition experiments were performed with wheat and rye flours as solid phases, and grass and tree pollen as inhibitors. Five subjects experienced a positive reaction after flour inhalation (responders), whereas 20 subjects did not show such a reaction (non-responders). All responders showed sensitizations to flours, whereas only 25% of the non-responders demonstrated the same sensitization. Specific IgE concentrations to flours, but also to grass and tree pollen, were higher in responders. Inhibition experiments demonstrated cross-reactivity between flours and grass or tree pollen, with higher inhibition rates in responders. Subjects with pronounced sensitizations to grass or tree pollen, but without prior occupational exposure to flours, may experience both sensitization and allergic asthmatic reactions to flours due to cross-reactive grass and tree pollen allergens.

Associations of airway inflammation and responsiveness markers in non asthmatic subjects at start of apprenticeship

BackgroundBronchial Hyperresponsiveness (BHR) is considered a hallmark of asthma. Other methods are helpful in epidemiological respiratory health studies including Fractional Exhaled Nitric Oxide (FENO) and Eosinophils Percentage (EP) in nasal lavage fluid measuring markers for airway inflammation along with the Forced Oscillatory Technique measuring Airway resistance (AR). Can their outcomes discriminate profiles of respiratory health in healthy subjects starting apprenticeship in occupations with a risk of asthma?MethodsRhinoconjunctivitis, asthma-like symptoms, FEV1 and AR post-Methacholine Bronchial Challenge (MBC) test results, FENO measurements and EP were all investigated in apprentice bakers, pastry-makers and hairdressers not suffering from asthma. Multiple Correspondence Analysis (MCA) was simultaneously conducted in relation to these groups and this generated a synthetic partition (EI). Associations between groups of subjects based on BHR and EI respectively, as well as risk factors, symptoms and investigations were also assessed.ResultsAmong the 441 apprentice subjects, 45 (10%) declared rhinoconjunctivitis-like symptoms, 18 (4%) declared asthma-like symptoms and 26 (6%) suffered from BHR. The mean increase in AR post-MBC test was 21% (sd = 20.8%). The median of FENO values was 12.6 ppb (2.6-132 range). Twenty-six subjects (6.7%) had EP exceeding 14%. BHR was associated with atopy (p < 0.01) and highest FENO values (p = 0.09). EI identified 39 subjects with eosinophilic inflammation (highest values of FENO and eosinophils), which was associated with BHR and atopy.ConclusionsAre any of the identified markers predictive of increased inflammatory responsiveness or of development of symptoms caused by occupational exposures? Analysis of population follow-up will attempt to answer this question.

Early markers of airways inflammation and occupational asthma: Rationale, study design and follow-up rates among bakery, pastry and hairdressing apprentices

BackgroundOccupational asthma is a common type of asthma caused by a specific agent in the workplace. The basic alteration of occupational asthma is airways inflammation. Although most patients with occupational asthma are mature adults, there is evidence that airways inflammation starts soon after inception of exposure, including during apprenticeship. Airways hyper responsiveness to methacholine is a valid surrogate marker of airways inflammation, which has proved useful in occupational epidemiology. But it is time-consuming, requires active subject's cooperation and is not readily feasible. Other non-invasive and potentially more useful tests include the forced oscillation technique, measurement of fraction exhaled nitric oxide, and eosinophils count in nasal lavage fluid.Methods and designThis study aims to investigate early development of airways inflammation and asthma-like symptoms in apprentice bakers, pastry-makers and hairdressers, three populations at risk of occupational asthma whose work-related exposures involve agents of different nature. The objectives are to (i) examine the performance of the non-invasive tests cited above in detecting early airways inflammation that might eventually develop into occupational asthma; and (ii) evaluate whether, and how, constitutional (e.g. atopy) and behavioural (e.g. smoking) risk factors for occupational asthma modulate the effects of allergenic and/or irritative substances involved in these occupations. This paper presents the study rationale and detailed protocol.DiscussionAmong 441 volunteers included at the first visit, 354 attended the fourth one. Drop outs were investigated and showed unrelated to the study outcome. Sample size and follow-up participation rates suggest that the data collected in this study will allow it to meet its objectives.

The incidence of respiratory symptoms and sensitisation in baker apprentices

The aim of the current study was to describe the incidence of respiratory symptoms and allergic sensitisation and the sequence of events leading to respiratory symptoms among Danish baker apprentices (BA). A total of 114 BA were surveyed over a 20-month period. Questionnaires were completed along with spirometric analysis and skin-prick tests to common and work-related allergens. Bronchial hyperresponsiveness (BHR) was determined at baseline and at the end of the follow-up period. The incidences of work-related rhinitis and asthma-like symptoms were 22.1 and 10.0 cases.100 person-yrs(-1), respectively. At 20 months the cumulative incidence proportion was 40.2 and 20.5% for rhinitis and asthma-like symptoms, respectively. The cumulative incidence of occupational sensitisation was 6.1%. An increased risk of asthma-like symptoms was found in both atopic subjects and in females. In the BA with new onset respiratory symptoms, an increase in BHR from baseline was observed. Forced expiratory volume in one second and forced vital capacity did not change during the follow-up period. No relationship was observed between new sensitisation and new symptoms. In conclusion rhinitis- and asthma-like symptoms were found to develop commonly in Danish baker apprentices. The mechanism by which symptoms arose was perceived to reflect the development of an inflammation rather than the production of a specific immunoglobulin E pathway, as sensitisation to occupational allergens was rarely observed. Hence, respiratory symptoms and allergy may develop through separate pathways.

Allergy in bakers’ apprentices and factors associated to non-participation in a cohort study of allergic sensitization

To describe the prevalence of atopy and respiratory symptoms among baker apprentices at the start of the education and factors associated with non-participation in the study. A total of 346 students, 22.1(0.6) years of age, mean (SD), from the food production programme of technical colleges in Denmark were invited to participate in a 3 year study. Of the students, 187 agreed to participate and filled in a physician-administered questionnaire. The presence of atopy was determined by skin prick test (SPT) and serum allergen specific IgE (SpIgE). Bronchial hyper responsiveness to methacholine (PD(20) <or= 1,440 microg) was determined. Prevalence of atopy was 32%. The prevalence of symptoms from the lungs and nose was 19.8 and 25.5%, respectively. Significantly, more SPT reactions were seen in males compared to females (39 vs. 22%, P < 0.05). Sensitization towards flour was significantly more frequent if determined as SpIgE (7.3%) compared to SPT (0.5%). We found a positive association between atopy and lung symptoms OR 6.1 (2.8-13.2 SD) and nasal symptoms OR 3.7 (1.8-7.5 SD). The major reason for non-participation was fear of blood sampling (25.5%). The prevalence of atopy in bakers' apprentices was of the same magnitude in the general Danish population. Significantly, more male bakers' apprentices had atopy. This finding has major impact on the diagnostic procedures of occupational allergy in bakery workers emphasizing the need for standardization of the clinical tests. The main reasons for non-participation were, fear of blood-sampling (57%) and the 3 years commitment to the follow-up study (39%).

Respiratory allergy in apprentice bakers: do occupational allergies follow the allergic march?

This prospective study describes the incidence, risk factors and natural history of occupational respiratory allergy in apprentice bakers. Two hundred and eighty-seven apprentice bakers were examined using a questionnaire, skin prick tests (SPTs) to common and occupational allergens, evaluation of total serum IgE level and specific anti-flour and alpha-amylase IgE, before, 1 year and 2 years after the onset of vocational training. To diagnose occupational respiratory disease, spirometry, histamine and allergen-specific inhalation challenge tests were performed. The incidence of work-related chest symptoms was 4.2% in the first year and 8.6% in the second year of exposure. Hypersensitivity to occupational allergens developed in 4.6 and 8.2% of subjects, respectively. The incidence of occupational allergic rhinitis was 8.4% after 1 year and 12.5% after 2 years, and that of occupational asthma/cough-variant asthma 6.1 and 8.7%, respectively. The latency period of work-related rhinitis symptoms was 11.6 +/- 7.1 months and chest symptoms 12.9 +/- 5.5 months. Only in 20% of occupational asthmatics could allergic rhinitis be diagnosed a stage earlier. In 21 out of 25 subjects with occupational asthma, chronic cough was the sole clinical manifestation of the disease. Stepwise logistic regression analysis revealed that positive SPT to common allergens was a significant risk factor of hypersensitivity to occupational allergens (OR = 10.6, 95% CI 5.27; 21.45), occupational rhinitis (OR = 3.9, 95% CI 1.71; 9.14) and occupational asthma (OR = 7.4, 95% CI 3.01; 18.04). Moreover, positive SPT to occupational allergens on entry to the training was a significant risk factor of asthma (OR = 6.9, 95% CI 0.93; 51.38). The incidence of occupational asthma and rhinitis in apprentice bakers is high and increases z with the duration of exposure. Skin reactivity to common and occupational allergens is the main risk factor of bakers' asthma. Most cases of work-related respiratory symptoms among apprentice bakers are related to a specific sensitization. In most subjects who developed occupational asthma, rhinitis occurred at the same time as the chest symptoms did.

FS07.6 Efficacy of UVB radiation versus skin protection in the prevention of hand dermatitis in baker apprentices

In‐vitro and in‐vivo data suggest the efficacy of various skin protection measures in the prevention of hand dermatitis (HD). The aims and objectives of this intervention study was to quantify the efficacy of skin protection (SP) measures and UVB hardening in the prevention of HD. SP measures were compared against UVB hardening in a controlled clinical trial of 94 apprentices. The apprentices were assigned to the intervention arms class‐wise. Baker apprentices involved in a previous follow‐up study served as an additional historic control group representing no intervention. The apprentices were interviewed and examined in a standardised way at the beginning of the vocational training and at four follow‐ups. Transepidermal water loss (TEWL) was measured at the back of the hands. Point prevalence of HD in the groups after 6 months was highest in the controls (C)(29.1%) followed by the UVB‐group (19.4%) and the SP group (13.3%). UVB hardening and SP measures were associated with a reduction in HD prevalence by 9.7%(95%CI −8.5 to 28.1) and 15.8%(95%CI −2.4 to 33.9), respectively. Unadjusted logistic regression analysis showed atopy (OR = 4.74, 95%CI 1.12–20.11, p = 0.035) and skin care (OR 0.39, 95%CI 0.16–0.86, p = 0.023) to be independent risk factors. Application of SP measures reduced the OR for HD 0.8 (95%CI 0.17–3.70) and 0.33 (95%CI 0.09–1.23) fold compared to the UVB and C group, respectively. The trends in the clinical results were confirmed by statistically significant differences in TEWL values. Apprentices in the SP group consistently had a lower prevalence of HD compared to the apprentices in the UVB and C group. These trends were reinforced by statistically significant differences in TEWL levels. A multi‐centre trial is recommended to confirm the efficacy of SP measures in a larger randomised study.

The risk factors of occupational hypersensitivity in apprentice bakers -- the predictive value of atopy markers.

The aim of the study was to assess the predictive value of known risk factors of asthma, such as atopy, exposure to pet allergens at home, and tobacco smoking, in predicting the occurrence of occupational respiratory allergy due to high-molecular-weight allergens. A questionnaire study, skin-prick tests (SPTs) for common and occupational allergens, and evaluation of total and - in selected cases - specific IgE, were performed in 357 apprentice bakers before and after a year of vocational training. Mean age of examined subjects was 17.2+/-0.5 years. The prevalence of newly developed symptoms was 7% for rhinitis, 3.1% for chest symptoms, and 3.6% for skin symptoms. The frequency of at least one positive SPT result changed from 17.9% to 24.4% after the 1st year of vocational training, including SPTs for common allergens - from 16.8% to 22.7%, and for occupational allergens - from 2% to 8%. The proportion of subjects with elevated total IgE level increased from 38.7% to 44.3%. Generally, after a year of vocational training 9.2% of examined subjects presented hypersensitivity to occupational allergens. Logistic regression analysis revealed that positive results of SPTs for common allergens (odds ratio (OR) =4.4; 95% confidence intervals (CI) 1.9, 10.27) and elevated IgE level (OR=3.6; 95%CI 1.55, 8.57) were significant risk factors of hypersensitivity to occupational allergens. In apprentice bakers hypersensitivity to occupational allergens develops even during vocational training. SPTs for common allergens, performed before apprentices started their vocational training, would enable the identification of subjects at the highest risk of sensitisation to occupational allergens.

The risk factors for the development of occupational respiratory allergy in apprentice bakers

The risk factors for the development of occupational respiratory allergy in apprentice bakers

Prediction of sensitization to flour allergens

The purpose of the present study was to investigate the factors that may contribute to the sensitization to flour in baker's apprentices, and to predict this type of sensitization with a stepwise logistic regression model. Of the total of 258 baker's apprentices, 54 (20.9%) exhibited specific IgE development against flour allergens (wheat, rye, and/or barley). Allergologic variables, such as the total IgE level and IgE specific to grass pollen, tree pollen, weed pollen, molds, and animal dander, were found to correlate strongly with the sensitization to flour. However, the correlation between the presence of other manifest allergies and the sensitization to flour was weak. The presence of shadowing of the paranasal sinuses on the radiograph (mucosal thickening, opacity, air/fluid levels, and/or polypous shadowing) correlated with flour sensitization as well as with the leukocyte and lymphocyte counts in peripheral blood. Of the lung function data, only total lung capacity (in percentage of the predicted values) weakly correlated with the sensitization to flour. We were able to predict flour sensitization with a sensitivity of 63%, a specificity of 90%, and an efficiency of 84% by using the parameters that allow for the presence or absence of IgE specific to grass pollen and tree pollen, the presence or absence of radiographic shadowing, and total lung capacity in percentage of the predicted values.