Occupational exposure to respirable crystalline silica and incident idiopathic interstitial pneumonias and pulmonary sarcoidosis: a national prospective follow-up study.

BACKGROUND: Respirable crystalline silica is a well-known cause of silicosis but may also be associated with other types of interstitial lung disease. We examined the associations between occupational exposure to respirable crystalline silica and the risk of idiopathic interstitial pneumonias, pulmonary sarcoidosis and silicosis. METHODS: The total Danish working population was followed 1977-2015. Annual individual exposure to respirable crystalline silica was estimated using a quantitative job exposure matrix. Cases were identified in the Danish National Patient Register. We conducted adjusted analyses of exposure-response relations between cumulative silica exposure and other exposure metrics and idiopathic interstitial pneumonias, pulmonary sarcoidosis and silicosis. RESULTS: Mean cumulative exposure was 125 µg/m3-years among exposed workers. We observed increasing incidence rate ratios with increasing cumulative silica exposure for idiopathic interstitial pneumonias, pulmonary sarcoidosis and silicosis. For idiopathic interstitial pneumonias and pulmonary sarcoidosis, trends per 50 µg/m3-years were 1.03 (95% CI 1.02 to 1.03) and 1.06 (95% CI 1.04 to 1.07), respectively. For silicosis, we observed the well-known exposure-response relation with a trend per 50 µg/m3-years of 1.20 (95% CI 1.17 to 1.23). CONCLUSION: This study suggests that silica inhalation may be related to pulmonary sarcoidosis and idiopathic interstitial pneumonias, though these findings may to some extent be explained by diagnostic misclassification. The observed exposure-response relations for silicosis at lower cumulative exposure levels than previously reported need to be corroborated in analyses that address the limitations of this study.

Occupational exposure to epoxy components and risk of dermatitis: A registry-based follow-up study of the wind turbine industry.

BACKGROUND: Allergic contact allergy and dermatitis are frequently reported among epoxy-exposed workers. OBJECTIVES: To determine the risk of dermatitis associated with epoxy exposure. METHODS: We followed 825 epoxy-exposed and 1091 non-exposed blue-collar workers, and 493 white-collar workers of a Danish wind turbine blade factory during 2017-2022 with linked data from national health registers on diagnoses, patch testing, or fillings of prescriptions for topical corticosteroids. Incidence rate ratios of dermatitis or a first-time topical corticosteroid prescription were estimated with Poisson regression using non-exposed blue-collar workers as reference. We similarly estimated incidence rate ratios for the duration of epoxy exposure and current epoxy exposure. RESULTS: Epoxy-exposed blue-collar workers showed a dermatitis incidence rate of 2.1 per 100 000 person days, a two-fold increased risk of dermatitis and a 20% increased risk of filling a prescription for topical corticosteroids. Incidence rate ratios were higher during early exposure and declined with further exposure for both outcomes. White-collar workers had generally lower risks. CONCLUSION: We observed an increased risk of dermatitis following epoxy exposure confirming previous case reports and cross-sectional studies emphasizing the need for intensified focus on preventive efforts for this group of workers.

Prevalence of Chronic Obstructive Pulmonary Disease and Chronic Bronchitis Among Predominantly Smoking Workers in the Seafood Industry in Greenland.

Introduction: For decades, the prevalence of smoking has been high in Greenland. Even so, the prevalence of chronic obstructive pulmonary disease (COPD), a smoking-related disease, remains largely unexplored. This cross-sectional study aimed to estimate the prevalence of COPD and chronic bronchitis (CB) among Inuit workers in the seafood industry in Greenland. Methods: A total of 355 participants, 254 males and 101 females, met the inclusion criteria. Participants had a mean age of 38 years (standard deviation 13.5; range 17-68 years). COPD was diagnosed based on post-bronchodilator ratio between forced expiratory volume within one second and forced vital capacity (FEV1/FVC) below the lower limit of normal (LLN) according to the Global Lung Function Initiative. Participants completed a questionnaire aiming to diagnose CB. Results: The overall prevalence was 9.9% for COPD; 7.4% for CB. Participants were predominantly smokers; 73.2% active smokers, 91.8% active or former smokers. The prevalence of COPD was high, especially among those under 40 years of age. Both COPD and CB were associated with smoking status. Discussion: This study among Greenlandic seafood workers found that smoking was a risk factor for COPD and CB among Greenlanders of Inuit origin. The high prevalence of COPD and the high prevalence of smoking underlines the importance of further initiatives to reduce smoking in Greenland.

Association of perceived work pace and physical work demands with occupational accidents: a cross-sectional study of ageing male construction workers in Denmark.

BACKGROUND: Occupational accidents continue to be a significant public health challenge worldwide. Construction workers in particular are at high risk of occupational accidents, and thus it is of major importance to identify possible predictors of occupational accidents among construction workers. We aimed to investigate the association between self-reported work pace and physical work demands and occupational accidents among ageing male construction workers in Denmark. METHODS: Data on perceived work pace, physical work demands, and occupational accidents was acquired from questionnaires sent to ageing construction workers in Denmark in 2016 as part of the ALFA project (ALdring og Fysisk Arbejde; Ageing and Physical Work). A sample of 1270 Danish male construction workers above 50 years of age was included in the present study. Multiple logistic regression models were applied, with adjustments for age, smoking, body mass index, musculoskeletal disorders, occupation, work experience, and support at work. RESULTS: Of 1270 construction workers, 166 (13.1%) reported an occupational accident within the last 12 months. There was no significant association between perceived work pace and occupational accidents, but physical work demands were associated with higher odds for occupational accidents, with an odds ratio of 2.27 (95% confidence interval 1.26-4.10) for medium physical work demands and 2.62 (95% confidence interval 1.50-4.57) for high physical work demands. CONCLUSIONS: Ageing male construction workers with high physical work demands had statistically significant higher odds of having an occupational accident. By contrast, perceived work pace was not associated with occupational accidents in this large cross-sectional study.

Historical Asbestos Measurements in Denmark-A National Database.

OBJECTIVES: Due to the long lag-time for health outcomes, historical asbestos exposure measurements are valuable to support assessments of associated occupational health effects, and also to assess time trends and effects of preventive measures. METHODS: Different sources of stored data were collated, assessed and refined to create a harmonized database on historical asbestos fibre concentrations measured in specific work tasks and different industries. The final database contains 9236 asbestos measurements from Danish workplaces collected from 1971 to 1997. RESULTS: The geometric mean of asbestos concentrations in different occupations and tasks ranged from 0.003 to 35 fibres cm-3. Highest concentrations were registered during handling of asbestos products in the construction services during the period 1981-1997. Although all the measured asbestos exposures without the use of respiratory equipment by the worker in the period of 1971-1997 exceeded the current 8-h time-weighted average exposure limit of 0.1 fibres cm-3, the majority of samples collected in the earlier period of 1971 to 1980 did not exceed the exposure limit of 2 fibres cm-3, which was in place at the time. All exposure data obtained from 1980 and onwards were found to be one seventh of the mean fibre concentrations in the previous measurement period. The impact of time shows a clear exponentially decreasing trend-line. CONCLUSIONS: Despite limitations in coverage of different occupations and tasks associated with the inventoried historical asbestos measurements, the data are helpful to identify specific work scenarios within an industry, where relatively high asbestos exposure levels may still occur or have occurred from 1971 to 1997.

An RCT of acute health effects in COPD-patients after passive vape exposure from e-cigarettes.

Background: E-cigarette use has been shown to have short-term acute effects among active users but less is known of the acute passive effects, particularly among individuals with existing respiratory diseases. Objective: To investigate local and systemic effects of short-term passive vape exposure among patients with mild or moderate chronic obstructive pulmonary disease (COPD). Methods: In a double-blinded crossover study 16 non-smoking COPD-patients (mean age 68) were randomly exposed for 4 h to passive vape (median PM2.5: 18 µg/m3 (range: 8-333)) and clean air (PM2.5 < 6 µg/m3) separated by 14 days. Particles were measured using an ultrafine particle counter (P-TRAK) and a scanning mobility particle sizer (SMPS). Health effects including Surfactant Protein-A (SP-A) and albumin in exhaled air, spirometry, FeNO, and plasma proteins were evaluated before, right after, and 24 hours after exposure. Participants reported symptoms throughout exposure sessions. Data were analyzed using mixed models. Results: SP-A in exhaled air was negatively affected by exposure to vape and several plasma proteins increased significantly. Throat irritation was more pronounced during passive vape exposure, while FVC and FEV1 decreased, however, not significantly. Conclusions: SP-A in exhaled air and some plasma proteins were affected by passive vape in patients with COPD indicating inflammation, showing that passive vape exposure is potentially harmful.

[Work-up of asbestosis and estimation of asbestos exposure in an occupational context].

Asbestosis is interstitial lung fibrosis due to inhalation of asbestos fibres. Up to the ban of import in 1986, 0.7 mil tons had been used in Denmark. The diagnosis of asbestosis is a challenge because of long latency time and very few national occupational asbestos measurements. The cornerstone of exposure assessment is a thorough occupational history, investigation of asbestos content in products used, search for possible and relevant measurements of asbestos fibres in the air, and results of lung biopsies, if present. Although no definite lower limit of exposure can be defined, a cumulated exposure of > 10 fibre-years is a relevant measure for exposure defining the disease, as one fibre-year equals one asbestos fibre/cm3 air/occupational year.

Biomarkers of oxidative stress and inflammation after wood smoke exposure in a reconstructed Viking Age house.

Exposure to particles from combustion of wood is associated with respiratory symptoms, whereas there is limited knowledge about systemic effects. We investigated effects on systemic inflammation, oxidative stress and DNA damage in humans who lived in a reconstructed Viking Age house, with indoor combustion of wood for heating and cooking. The subjects were exposed to high indoor concentrations of PM2.5 (700-3,600 µg/m(3)), CO (10.7-15.3 ppm) and NO2 (140-154 µg/m(3)) during a 1-week stay. Nevertheless, there were unaltered levels of genotoxicity, determined as DNA strand breaks and formamidopyrimidine DNA glycosylase and oxoguanine DNA glycosylase 1 sensitive sites in peripheral blood mononuclear cells. There were also unaltered expression levels of OGG1, HMOX1, CCL2, IL8, and TNF levels in leukocytes. In serum, there were unaltered levels of C-reactive protein, IL6, IL8, TNF, lactate dehydrogenase, cholesterol, triglycerides, and high-density lipoproteins. The wood smoke exposure was associated with decreased serum levels of sICAM-1, and a tendency to decreased sVCAM-1 levels. There was a minor increase in the levels of circulating monocytes expressing CD31, whereas there were unaltered expression levels of CD11b, CD49d, and CD62L on monocytes after the stay in the house. In conclusion, even a high inhalation exposure to wood smoke was associated with limited systemic effects on markers of oxidative stress, DNA damage, inflammation, and monocyte activation.

Systemic effects of wood smoke in a short-term experimental exposure study of atopic volunteers.

OBJECTIVE: To investigate whether short-term systemic effects of wood smoke occurred in atopic subjects after experimental wood smoke exposures. METHODS: A double-blind climate chamber study was conducted on 20 healthy atopic subjects with exposures to filtered air and wood smoke. Pneumoproteins, coagulation and adhesion factors, and cytokines were measured. Heart rate was monitored with pulse monitors. Data were analyzed with mixed models. RESULTS: Few differences in the outcomes were observed. Plasma tissue factor remained elevated during filtered air exposure (P = 0.002). P-selectin declined independent of exposure (P = 0.0006). Interleukin-6 increased after filtered air (P = 0.03). CONCLUSIONS: The study confirmed previous observations among nonatopics of limited changes after a 3-hour wood smoke exposure.

A method to assess the potential effects of air pollution mitigation on healthcare costs.

OBJECTIVE: The aim of this study was to develop a method to assess the potential effects of air pollution mitigation on healthcare costs and to apply this method to assess the potential savings related to a reduction in fine particle matter in Denmark. METHODS: The effects of air pollution on health were used to identify "exposed" individuals (i.e., cases). Coronary heart disease, stroke, chronic obstructive pulmonary disease, and lung cancer were considered to be associated with air pollution. We used propensity score matching, two-part estimation, and Lin's method to estimate healthcare costs. Subsequently, we multiplied the number of saved cases due to mitigation with the healthcare costs to arrive to an expression for healthcare cost savings. RESULTS: The potential cost saving in the healthcare system arising from a modelled reduction in air pollution was estimated at €0.1-2.6 million per 100,000 inhabitants for the four diseases. CONCLUSION: We have illustrated an application of a method to assess the potential changes in healthcare costs due to a reduction in air pollution. The method relies on a large volume of administrative data and combines a number of established methods for epidemiological analysis.

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/m(3), 400 µg/m(3), 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.

Seasonal variations in work-related health effects in swine farm workers.

The aim of the project was to investigate whether there were diminished health effects in swine farm workers during summer compared with winter, as seasonal differences in concentrations of bioaerosols have been reported. Twenty-four workers were visited once during each season. Before and after a work shift, they underwent lung function testing and blood sampling. During work, they wore personal air sampling equipment. The mean endotoxin exposure of the workers was highest during winter (25,690 vs. 6,553 EU/m(3); p = 0.004). Although exposures to endotoxin and CO(2) varied between the seasons, no differences in lung function were found between them. White blood cell concentration increased over the work shift from 5.74-6.82 in winter (p < 0.0001) and from 5.80-6.38 in summer (p = 0.014). These increases differed between the two seasons (p = 0.032). Plasma tumour necrosis factor concentrations fell over the work shift only during winter (1.34-1.24 pg/ml (p = 0.03) (p = 0.014 for the difference between seasons). Plasma interleukin-6 increased over the work shift independently of season (p = 0.0006). The study supported our hypothesis of adverse effects on lung function and immune system, but less so during summer than during winter among Quebec swine farm workers.

Respiratory symptoms and ex vivo cytokine release are associated in workers processing herring.

OBJECTIVE: To determine the prevalence of respiratory symptoms among workers processing herring and assess ex vivo cytokine release in response to agents at their workplace. METHODS: We applied a questionnaire, and performed skin prick testing and pulmonary investigations in 36 workers at two herring factories, using 31 municipal workers as controls. In a whole blood assay (WBA), venous blood from the subjects was incubated with lipopolysaccharide (LPS), beta(1,3)-glucan or sterile-filtered, fish constituents such as skin and rinsing water. We determined the IL-1beta and IL-8 release in the plasma by chemiluminescence ELISA. RESULTS: Among smoking fish-factory workers the forced vital capacity (FVC) was higher (per cent predicted 92.0 vs 85.0; P=0.028) than among municipal workers. Fish rinsing water induced WBA IL-8 release to higher levels than LPS and glucan. Among non-smokers the induced IL-1beta release for rinsing water ( P=0.007) and the IL-8 release for skin ( P=0.001) and meat ( P=0.003) were higher in fish-factory workers than in municipal workers. The IL-1beta release for rinsing water ( P=0.028) and skin ( P=0.041) was higher among non-smokers than among smokers, and so was the IL-8 release for rinsing water ( P=0.008). CONCLUSIONS: Assessing the cytokine release by use of the WBA we identified substances in the occupational environment with a pro-inflammatory potential comparable to that of LPS. The cytokine release for fish constituents was highest among non-smoking fish-factory workers. The results suggest a priming effect of the work exposure.