Guidelines for the management of work-related asthma

Work-related asthma, which includes occupational asthma and work-aggravated asthma, has become one of the most prevalent occupational lung diseases. These guidelines aim to upgrade occupational health standards, contribute importantly to transnational legal harmonisation and reduce the high socio-economic burden caused by this disorder. A systematic literature search related to five key questions was performed: diagnostics; risk factors; outcome of management options; medical screening and surveillance; controlling exposure for primary prevention. Each of the 1,329 retrieved papers was reviewed by two experts, followed by Scottish Intercollegiate Guidelines Network grading, and formulation of statements graded according to the Royal College of General Practitioners' three-star system. Recommendations were made on the basis of the evidence-based statements, which comprise the following major evidence-based strategic points. 1) A comprehensive diagnostic approach considering the individual specific aspects is recommended. 2) Early recognition and diagnosis is necessary for timely and appropriate preventative measures. 3) A stratified medical screening strategy and surveillance programme should be applied to at-risk workers. 4) Whenever possible, removing exposure to the causative agent should be achieved, as it leads to the best health outcome. If this is not possible, reduction is the second best option, whereas respirators are of limited value. 5) Exposure elimination should be the preferred primary prevention approach.

Organic dust toxic syndrome at a grass seed plant caused by exposure to high concentrations of bioaerosols

We describe an outbreak of sudden health problems in workers at a Danish grass seed plant after exposure to a particularly dusty lot of grass seeds. The seeds are called problematic seeds. The association between development of organic dust toxic syndrome (ODTS) and the handling of grass seeds causing exposure was assessed in a four-step model: (i) identification of exposure source, (ii) characterization of the emission of bioaerosols from the problematic and reference seeds, (iii) personal and stationary exposure measurement at the plant and (iv) repeated health examinations. The grass seeds were identified as the exposure source; the emissions of some bioaerosol components were up to 10(7) times higher from the problematic seeds than from reference seeds. Cleaning of the seeds was not enough to sufficiently reduce the high emission from the problematic seeds. Emission in terms of dust was 3.4 times as high from the problematic cleaned seeds as from cleaned reference seeds. The personal exposure reached 3 × 10(5) endotoxin units m(-3), 1 × 10(6) colony-forming units (cfu) of thermophilic actinomycetes m(-3), 8 × 10(5) cfu of Aspergillus fumigatus m(-3) and 9 × 10(6) hyphal fragments m(-3). Several workers working with the problematic seeds had symptoms consistent with ODTS. The most severe symptoms were found for the workers performing the tasks causing highest exposure. Respiratory airway protection proved efficient to avoid development of ODTS. Work with reference seeds did not cause workers to develop ODTS. Exposure was during work with the problematic seeds higher than suggested occupational exposure limits but lower than in studies where researchers for some minutes have repeated a single task expected to cause ODTS. In this study, many different bioaerosol components were measured during a whole working day. We cannot know, whether it is the combination of different bioaerosol components or a single component which is responsible for the development of ODTS. In conclusion, workers developed specific health symptoms due to the high bioaerosol exposure and were diagnosed with ODTS. Exposure to high concentrations of endotoxin, actinomycetes, fungi, hyphal fragments, β-glucan, and A. fumigatus occurred when working with a dusty lot of grass seed. Suspicion should be elicited by seeds stored without being properly dried and by seeds producing more dust than usually.

Effects of wood smoke particles from wood-burning stoves on the respiratory health of atopic humans

Background

There is growing evidence that particulate air pollution derived from wood stoves causes acute inflammation in the respiratory system, increases the incidence of asthma and other allergic diseases, and increases respiratory morbidity and mortality. The objective of this study was to evaluate acute respiratory effects from short-term wood smoke exposure in humans. Twenty non-smoking atopic volunteers with normal lung function and without bronchial responsiveness were monitored during three different experimental exposure sessions, aiming at particle concentrations of about 200 μg/m³, 400 μg/m³, and clean air as control exposure. A balanced cross-over design was used and participants were randomly allocated to exposure orders. Particles were generated in a wood-burning facility and added to a full-scale climate chamber where the participants were exposed for 3 hours under controlled environmental conditions. Health effects were evaluated in relation to: peak expiratory flow (PEF), forced expiratory volume in the first second (FEV₁), and forced vital capacity (FVC). Furthermore, the effects were assessed in relation to changes in nasal patency and from markers of airway inflammation: fractional exhaled nitric oxide (FENO), exhaled breath condensate (EBC) and nasal lavage (NAL) samples were collected before, and at various intervals after exposure.

Results

No statistically significant effect of wood smoke exposure was found for lung function, for FENO, for NAL or for the nasal patency. Limited signs of airway inflammation were found in EBC.

Conclusion

In conclusion, short term exposure with wood smoke at a concentration normally found in a residential area with a high density of burning wood stoves causes only mild inflammatory response.

Exposure to inhalable dust and endotoxin among Danish livestock farmers: results from the SUS cohort study

Studies on personal dust and endotoxin concentrations among animal farmers have been either small or limited to a few sectors in their investigations. The present study aimed to provide comparable information on the levels and variability of exposure to personal dust and endotoxin in different types of animal farmers. 507 personal inhalable dust samples were collected from 327 farmers employed in 54 pig, 26 dairy, 3 poultry, and 3 mink farms in Denmark. Measurements in pig and dairy farmers were full-shift and performed during summer and winter, while poultry and mink farmers were monitored during 4 well-defined production stages. The collected samples were measured for dust gravimetrically and analyzed for endotoxin by the Limulus amebocyte lysate assay. Simple statistics and random-effect analysis were used to describe the levels and the variability in measured dust and endotoxin exposure concentrations. Measured inhalable dust levels had an overall geometric mean of 2.5 mg m(-3) (range <LOD to 47.8) and endotoxin of 988 EU m(-3) (range <LOD to 374,000). The highest dust and endotoxin concentrations were measured among pig and poultry farmers, and were the lowest among dairy and mink farmers, respectively. Exposure among pig and cattle farmers was characterised by a substantial day-to-day variability that increased from the indoor to outdoor working environment. Only mink farmers complied with the Danish occupational exposure limit for total dust (3 mg m(-3)). More than 93% of our measurements exceeded the recently proposed Dutch exposure-limit for endotoxin (90 EU m(-3)). These findings suggest animal farmers to be exposed to high levels of dust and endotoxin consistent with an increased risk of developing respiratory symptoms and diseases. The development of preventive strategies to reduce exposure will require in-depth identification of factors that affect day-to-day variability in exposure.

Sensitisation to common allergens and respiratory symptoms in endotoxin exposed workers: a pooled analysis

OBJECTIVE

To test the hypotheses that current endotoxin exposure is inversely associated with allergic sensitisation and positively associated with non-allergic respiratory diseases in four occupationally exposed populations using a standardised analytical approach.

METHODS

Data were pooled from four epidemiological studies including 3883 Dutch and Danish employees in veterinary medicine, agriculture and power plants using biofuel. Endotoxin exposure was estimated by quantitative job-exposure matrices specific for the study populations. Dose-response relationships between exposure, IgE-mediated sensitisation to common allergens and self-reported health symptoms were assessed using logistic regression and generalised additive modelling. Adjustments were made for study, age, sex, atopic predisposition, smoking habit and farm childhood. Heterogeneity was assessed by analysis stratified by study.

RESULTS

Current endotoxin exposure was dose-dependently associated with a reduced prevalence of allergic sensitisation (ORs of 0.92, 0.81 and 0.66 for low mediate, high mediate and high exposure) and hay fever (ORs of 1.16, 0.81 and 0.58). Endotoxin exposure was a risk factor for organic dust toxic syndrome, and levels above 100 EU/m(3) significantly increased the risk of chronic bronchitis (p<0.0001). Stratification by farm childhood showed no effect modification except for allergic sensitisation. Only among workers without a farm childhood, endotoxin exposure was inversely associated with allergic sensitisation. Heterogeneity was primarily present for biofuel workers.

CONCLUSIONS

Occupational endotoxin exposure has a protective effect on allergic sensitisation and hay fever but increases the risk for organic dust toxic syndrome and chronic bronchitis. Endotoxin's protective effects are most clearly observed among agricultural workers.

[It is uncertain if caesarean section is a risk factor to the development of asthma]

In Denmark the prevalence of both asthma and caesarean section has increased during the last 20 years. This review investigates the coherence between caesarean section and the development of asthma. Twelve epidemiological articles about children over three years were included. Eight of 12 studies discovered no association between caesarean section and asthma. There is no difference in the quality of the studies. We can conclude that it is uncertain if caesarean section is a risk factor to the development of asthma, but it cannot be eliminated that asthma is one of many consequences of caesarean section.

Does the use of biofuels affect respiratory health among male Danish energy plant workers?

OBJECTIVES

To study asthma, respiratory symptoms and lung function among energy plant employees working with woodchip, straw or conventional fuel.

METHODS

Respiratory symptoms in 138 woodchip workers, 94 straw workers and 107 control workers from 85 heating- or combined heating and power plants were collected by questionnaire. Spirometry, metacholine provocation tests and skin prick tests were performed on 310 workers. The work area concentrations of 'total dust' (n=181), airborne endotoxin (n=179), cultivable Aspergillus fumigatus (n=373) and cultivable fungi (n=406) were measured at each plant. Personal exposure was calculated from the time spent on different tasks and average work area exposures.

RESULTS

Median (range) average personal exposures in biofuel plants were 0.05 (0 to 0.33) mg/m³ for 'total' dust and 3.5 (0 to 294) endotoxin units/m³ for endotoxin. Fungi were cultivated from filters (straw plants) or slit samplers (woodchip plants); the average personal exposures were 5.230×10³ (118 to 1.85×10⁴) and 1.03×10³ (364 to 5.01×10³) colony-forming units/m³ respectively. Exposure levels were increased in biofuel plants compared with conventional plants. The prevalence of respiratory symptoms among conventional plant and biofuel plant workers was comparable, except for asthma symptoms among non-smokers, which were higher among straw workers compared with controls (9.4 vs 0%, p<0.05). A trend for increasing respiratory symptoms with increasing endotoxin exposure was seen with ORs between 3.1 (1.1 to 8.8) (work-related nose symptoms) and 8.1 (1.5 to 44.4) (asthma symptoms) for the most exposed group. Associations between fungal exposure and respiratory symptoms were less clear but suggested cultivable fungi to be associated with asthma symptoms and work-related respiratory symptoms. No associations were seen between lung function and the level of endotoxin or fungal exposure.

CONCLUSIONS

Working with biofuel at an energy plant does not generally enhance the prevalence of respiratory symptoms. However, the exposure level to micro-organisms has an impact on the occurrence of respiratory symptoms among biofuel workers.

Immunoglobulin E-mediated sensitization to pine and beech dust in relation to wood dust exposure levels and respiratory symptoms in the furniture industry

OBJECTIVES

Wood dust exposure may cause Immunoglobulin E (IgE)-mediated allergic diseases. Our objectives were to estimate pine and beech dust sensitization rates among woodworkers and a reference group, explore the association between exposure and sensitization and between sensitization and respiratory symptoms, and finally investigate the impact of proteinogenic specific IgE (sIgE) epitopes on respiratory symptoms.

METHODS

In a Danish study among 52 furniture factories and 2 reference factories, we evaluated the workers' asthma and rhinitis status using questionnaires and blood samples collected from 1506 woodworkers and 195 references. Workers with asthma symptoms (N=298), a random study sample (N=399) and a random rhinitis sample (N=100) were evaluated for IgE-mediated sensitization to pine and beech dust.

RESULTS

The prevalence of pine and beech sensitization among current woodworkers was 1.7 and 3.1%, respectively. No differences in sensitization rates were found between woodworkers and references, but the prevalence of wood dust sensitization was dose-dependently associated with the current level of wood dust exposure. No relation was observed between wood dust sensitization per se and respiratory symptoms. Only symptomatic subjects had proteinogenic IgE epitopes to pine. Increased odds ratios for sIgE based on proteinogenic epitopes to beech and respiratory symptoms were found, although they were not statistically significant.

CONCLUSIONS

Sensitization rates to pine and beech were the same for woodworkers and references but dependent on the current wood dust exposure level. The importance of beech and pine wood sensitization is limited, but may be of clinical significance for a few workers if the IgE epitopes are proteinogenic.

The cohort of young Danish farmers - A longitudinal study of the health effects of farming exposure

Working in agriculture poses a serious risk for development of respiratory diseases, especially when working in animal housing. Animal workers are exposed to a mixture of organic and inorganic dust together with fumes and gases, including allergens and microbial-associated molecular patterns with a potentially major impact on respiratory health and the immune system. Exposure to microbial agents in animal housing is associated with an increased prevalence of respiratory symptoms, including bronchial hyperresponsiveness, accelerated lung function decline, and neutrophil-mediated inflammation. These clinical findings are often seen without IgE-mediated sensitization. In fact it has been found in recent studies that the prevalence of atopic sensitization and atopic asthma is low among farmers compared with other populations. The SUS study was designed to identify the type and occurrence of respiratory symptoms and disease, and to investigate risk factors for respiratory disorders and changes in lung function among young farming students. The cohort of young Danish farmers was established in 1992/1994 and followed up in 2007/2008 with a participation rate of 51.7%. The cohort consists of 1734 male farming students, 230 female farming students, and 407 army recruits as controls.

Mutations in TP53 tumor suppressor gene in wood dust-related sinonasal cancer

The causal role of work-related exposure to wood dust in the development of sinonasal cancer has long been established by numerous epidemiologic studies. To study molecular changes in these tumors, we analyzed TP53 gene mutations in 358 sinonasal cancer cases with or without occupational exposure to wood dust, using capillary electrophoresis single-strand conformation polymorphism analysis and direct sequencing. A significant association between wood-dust exposure and adenocarcinoma histology was observed [adjusted odds ratio (OR) 12.6, 95% confidence interval (CI), 5.0-31.6]. TP53 mutations occurred in all histologies, with an overall frequency of 77%. TP53 mutation positive status was most common in adenocarcinoma (OR 2.0, 95% CI, 1.1-3.7; compared with squamous cell carcinoma), and mutation positivity showed an overall, nonsignificant association with wood-dust exposure (OR 1.6, 95% CI, 0.8-3.1). Risk of TP53 mutation was significantly increased in association with duration (> or =24 years, OR 5.1, 95% CI, 1.5-17.1), average level (>2 mg/m(3); OR 3.6, 95% CI, 1.2-10.8) and cumulative level (> or =30 mg/m(3) x years; OR 3.5, 95% CI, 1.2-10.7) of wood-dust exposure; adjustment for formaldehyde affected the ORs only slightly. Smoking did not influence the occurrence of TP53 mutation; however, it was associated with multiple mutations (p = 0.03). As far as we are aware, this is the first study to demonstrate a high prevalence of TP53 mutation-positive cases in a large collection of sinonasal cancers with data on occupational exposure. Our results indicate that mutational mechanisms, in particular TP53 mutations, are associated with work-related exposure to wood dust in sinonasal cancer.

Increased incidence of respiratory symptoms among female woodworkers exposed to dry wood

The aim of the present study was to investigate the occurrence of new respiratory symptoms in relation to wood dust exposure in a 6-yr follow-up study. A total of 1,377 woodworkers (1,137 males; 240 females) and 297 reference workers (137 males; 160 females) participated. Data on respiratory symptoms, employment and smoking habits were collected. Wood dust exposure was assessed from baseline dust measurements, and cumulative wood dust exposure was assessed by study-specific job exposure matrices and exposure time. The geometric mean (geometric sd) dust level decreased during the study period from 0.94 (2.1) to 0.60 (1.6) mg.m(-3). Adjusted analysis revealed positive associations for cumulative incidence proportion of chronic bronchitis and daily coughing for female woodworkers versus female reference workers. The cumulative incidence proportion of daily coughing and chronic bronchitis were found to be associated with baseline wood dust exposure in a dose-dependent manner. The odds ratio (95% confidence interval) for daily coughing (with reference to the lowest exposure quartile) was 1.6 (0.6-4.3), 3.2 (0.9-6.8) and 3.8 (1.5-9.7), respectively, in the second and third lowest and the highest quartile. The figures for chronic bronchitis were, accordingly, 2.3 (0.4-14.5), 3.0 (0.5-18.7) and 6.0 (1.2-28.8). In conclusion, female woodworkers in this low exposure cohort showed an increased incidence of coughing and bronchitis, whereas no relations to wood dust exposure were seen for male woodworkers.

Airborne fungal and bacterial components in PM1 dust from biofuel plants

Fungi grown in pure cultures produce DNA- or RNA-containing particles smaller than spore size (<1.5 microm). High exposures to fungi and bacteria are observed at biofuel plants. Airborne cultivable bacteria are often described to be present in clusters or associated with larger particles with an aerodynamic diameter (d(ae)) of 2-8 microm. In this study, we investigate whether airborne fungal components smaller than spore size are present in bioaerosols in working areas at biofuel plants. Furthermore, we measure the exposure to bacteria and fungal components in airborne particulate matter (PM) with a D(50) of 1 microm (called PM(1) dust). PM(1) was sampled using Triplex cyclones at a working area at 14 Danish biofuel plants. Millipore cassettes were used to sample 'total dust'. The PM(1) particles (29 samples) were analysed for content of 11 different components and the total dust was analysed for cultivable fungi, N-acetyl-beta-D-glucosaminidase (NAGase), and (1 --> 3)-beta-D-glucans. In the 29 PM(1) samples, cultivable fungi were found in six samples and with a median concentration below detection level. Using microscopy, fungal spores were identified in 22 samples. The components NAGase and (1 --> 3)-beta-D-glucans, which are mainly associated with fungi, were present in all PM(1) samples. Thermophilic actinomycetes were present in 23 of the 29 PM(1) samples [average = 739 colony-forming units (CFU) m(-3)]. Cultivable and 'total bacteria' were found in average concentrations of, respectively, 249 CFU m(-3) and 1.8 x 10(5) m(-3). DNA- and RNA-containing particles of different lengths were counted by microscopy and revealed a high concentration of particles with a length of 0.5-1.5 microm and only few particles >1.5 microm. The number of cultivable fungi and beta-glucan in the total dust correlated significantly with the number of DNA/RNA-containing particles with lengths of between 1.0 and 1.5 microm, with DNA/RNA-containing particles >1.5 microm, and with other fungal components in PM(1) dust. Airborne beta-glucan and NAGase were found in PM(1) samples where no cultivable fungi were present, and beta-glucan and NAGase were found in higher concentrations per fungal spore in PM(1) dust than in total dust. This indicates that fungal particles smaller than fungal spore size are present in the air at the plants. Furthermore, many bacteria, including actinomycetes, were present in PM(1) dust. Only 0.2% of the bacteria in PM(1) dust were cultivable.

[Screening for asbestos-related conditions]

Screening programs for early detection of asbestos-related cancer have been considered. Conventional X-ray, computed tomography of the thorax, and the biomarkers osteopontin and mesothelin have been critically reviewed in the literature, together with survival data from screening programs in asbestos-exposed populations. Data do not currently support implementation of screening programs for asbestos-exposed persons in Denmark. Since mesothelioma is most often an occupational disease, these patients should be admitted to an occupational clinic for aetiological evaluation.

Determinants of wood dust exposure in the Danish furniture industry--results from two cross-sectional studies 6 years apart

Objectives: This paper investigates determinants of wood dust exposure and trends in dust level in the furniture industry of Viborg County, Denmark, using data from two cross-sectional studies 6 years apart.

Methods: During the winter 1997/1998, 54 factories were visited (hereafter study 1). In the winter 2003/2004, 27 factories were revisited, and personal dust measurements were repeated. In addition, 14 new factories were included (hereafter study 2). A total of 2303 woodworkers participated in study 1, and 2358 measurements from 1702 workers were available. From study 2, 1581 woodworkers participated and 1355 measurements from 1044 workers were available. Information on occupational variables describing potential determinants of exposures like work task, exhaust ventilation, enclosure and cleaning procedures were collected. A total of 2627 measurements and 1907 persons were included in the final mixed model in order to explore determinants of exposure and trends in dust level.

Results: The overall inhalable wood dust concentration (geometric means (geometric standard deviation)) has decreased from 0.95 mg/m³ (2.05) in study 1 to 0.60 mg/m³ (1.63) in study 2, representing a 7% annual decrease in dust concentration, which was confirmed in the mixed model. From study 1 to study 2 there has been a change towards less manual work and more efficient cleaning methods, but on the contrary also more inadequate exhaust ventilation systems. The following determinants were found to ‘increase’ dust concentration: sanding; use of compressed air; use of full-automatic machines; manual work; cleaning of work pieces with compressed air; kitchen producing factories and small factories (<20 employees). The following determinants of exposure were found to ‘decrease’ dust concentration: manual assembling/packing; sanding with adequate exhaust ventilation; adequate exhaust ventilation; vacuum cleaning of machines and special cleaning staff.

Conclusions: Despite a substantial drop in the dust concentration during the last 6 years in the furniture industry in Viborg County, further improvements are possible. There should be more focus on improved exhaust ventilation, professional cleaning methods and avoiding use of compressed air.

K-ras mutations in sinonasal cancers in relation to wood dust exposure

Background

Cancer in the sinonasal tract is rare, but persons who have been occupationally exposed to wood dust have a substantially increased risk. It has been estimated that approximately 3.6 million workers are exposed to inhalable wood dust in EU. In previous small studies of this cancer, ras mutations were suggested to be related to wood dust exposure, but these studies were too limited to detect statistically significant associations.

Methods

We examined 174 cases of sinonasal cancer diagnosed in Denmark in the period from 1991 to 2001. To ensure uniformity, all histological diagnoses were carefully reviewed pathologically before inclusion. Paraffin embedded tumour samples from 58 adenocarcinomas, 109 squamous cell carcinomas and 7 other carcinomas were analysed for K-ras codon 12, 13 and 61 point mutations by restriction fragment length polymorphisms and direct sequencing. Information on occupational exposure to wood dust and to potential confounders was obtained from telephone interviews and from registry data.

Results

Among the patients in this study, exposure to wood dust was associated with a 21-fold increased risk of having an adenocarcinoma than a squamous cell carcinoma compared to unexposed [OR = 21.0, CI = 8.0–55.0]. K-ras was mutated in 13% of the adenocarcinomas (seven patients) and in 1% of squamous cell carcinomas (one patient). Of these eight mutations, five mutations were located in the codon 12. The exact sequence change of remaining three could not be identified unambiguously. Among the five identified mutations, the G→A transition was the most common, and it was present in tumour tissue from two wood dust exposed adenocarcinoma patients and one patient with unknown exposure. Previously published studies of sinonasal cancer also identify the GGT → GAT transition as the most common and often related to wood dust exposure.

Conclusion

Patients exposed to wood dust seemed more likely to develop adenocarcinoma compared to squamous cell carcinomas. K-ras mutations were detected in 13% of adenocarcinomas. In this study and previously published studies of sinonasal cancer the found K-ras mutations, were almost exclusively G → A transitions. In conclusion, our study, based on a large representative collection of human SNC tumours, indicates that K-ras mutations are relatively infrequent, and most commonly occur in adenocarcinomas. Wood dust exposure alone was not found to be explanatory for the G→A mutations, but combination of exposure to tobacco, wood dust, and possibly other occupational agents may be a more likely explanation. Overall, the study suggests a limited role for K-ras mutations in development of sinonasal cancer.

[Does shift work cause spontaneous abortion, preterm birth or low birth weight?]

In Denmark 30% of females in the reproductive age regularly have shift work. 22 epidemiological papers were studied looking at associations between shift work and abortion, stillbirth, preterm birth, and birth weight. No convincing associations were observed between rotating shift work or fixed nightshift and negative pregnancy outcome. Some epidemiological support was found for a relation between fixed nightshift and late abortions/stillbirth. If fixed night work for all pregnant women is avoided, seven late abortion/stillbirths a year can be prevented. Fixed night work for pregnant women should be avoided.

Reference values for acoustic rhinometry in decongested school children and adults: the most sensitive measurement for change in nasal patency

INTRODUCTION

Only a limited reference material for acoustic rhinometry (AR) exists for school children most often calculated as the minimum cross-sectional area (MCA) in the non-decongested nose. We want to establish a set of reference values for MCA and nasal volumes for both adults and children and include values also for the decongested nose and determine the most sensitive measurement for change in nasal patency.

METHOD

Data from two studies were used; one comprising of 53 (20M, 33F) school children, age 9-11 years, and one comprising 146 (127M, 19F) healthy workers in the wood industry. Measurements by acoustic rhinometry were done before and after decongestion with two puffs of oxymethazoline nasal spray (1 mg/ml).

RESULTS

We found the decongested nasal volume (2-5 cm) to be 3.71 cm3 (3.58-3.84) in school children and 5.44 cm3 (5.21-5.67) in adults. We found the volume from 2-5 cm into the nasal cavity to be the most sensitive measure of change in nasal patency by decongestion, and MCA to be the least sensitive in both adults and children.

DISCUSSION

A larger study population of children, covering a broader range of age, is needed to stratify for gender and height. Our data in adults are in accordance with previous findings.

CONCLUSION

We have provided a reference material for acoustic rhinometry in school children and adults. Future evaluation of change in nasal patency should contain information about nasal volume from 2-5 cm into the nasal cavity and not just MCA in adults and school children.

[Allergology in Denmark 2006]

Allergic diseases are prominent, possibly life threatening, and a cause of worldwide concern. Evidence-based education of doctors in the specialty of allergology is a prerequisite for correct diagnosis and treatment of patients with allergic diseases. Recently, the specialty of allergology has been abolished in Denmark, without any upgrading of the education of doctors in related specialties. As a consequence, one could fear that allergy expertise will be disappearing. We propose collaboration among experts from related specialties with joint mediation of knowledge through a centre of allergology, common educational programs for doctors in training and physician specialists, and collaboration in regional centres of allergology.

Occupational exposure to inhalable wood dust in the member states of the European Union

The aim of this study was to estimate occupational exposure to inhalable wood dust by country, industry, the level of exposure and type of wood dust in 25 member states of the European Union (EU-25) for the purposes of hazard control, exposure surveillance and assessment of health risks. National labour force statistics, a country questionnaire (in 15 member states, EU-15), a company survey (in Finland, France, Germany and Spain), exposure measurements (from Denmark, Finland, France, Germany, The Netherlands and the United Kingdom) and expert judgements were used to generate preliminary estimates of exposure to different types of wood dust. The estimates were generated according to industrial class (six wood industries, four other sectors) and level of exposure (five classes). These estimates were reviewed and finalized by national experts from 15 member states. Crude estimates were generated also for 10 new member states (EU-10). The basic data and final estimates were included in the WOODEX database. In 2000-2003, about 3.6 million workers (2.0% of the employed EU-25 population) were occupationally exposed to inhalable wood dust. Of those, construction employed 1.2 million exposed workers (33%), mostly construction carpenters. The numbers of exposed workers were 700,000 (20%) in the furniture industry, 300,000 (9%) in the manufacture of builders' carpentry, 200,000 (5%) in sawmilling, 150,000 (4%) in forestry and <100,000 in other wood industries. In addition, there were 700,000 exposed workers (20%) in miscellaneous industries employing carpenters, joiners and other woodworkers. The numbers of exposed workers varied by country ranging from <3,000 in Luxembourg and Malta to 700,000 in Germany. The highest exposure levels were estimated to occur in the construction sector and furniture industry. Due to limited exposure data there was considerable uncertainty in the estimates concerning construction woodworkers. About 560,000 workers (16% of the exposed) may be exposed to a level exceeding 5 mg m(-3). Mixed exposure to more than one species of wood and dust from wooden boards was very common, but reliable data on exposure to different species of wood could not be retrieved. This kind of assessment procedure integrating measurement data, company data, country-specific data and expert judgement could also serve as one model for the assessment of other occupational exposures.