Occupational risk factors for airway obstruction in a population-based study in Northern Europe

Background: Airway obstruction is a key feature of asthma and chronic obstructive pulmonary diseases (COPD). Smoking habits and workplace exposures to vapors, gas, dusts, and fumes (VGDF) could cause or exacerbate airway obstruction. The aim of this study is to evaluate the risk of airway obstruction due to smoking and workplace exposure, and their interaction, in a large population-based study. Methods: In this cross-sectional study, a sample (n = 6153) of the Swedish population aged between 24 and 76 years underwent a questionnaire, clinical examination, blood test, and spirometry to gather information on airway obstruction classified by Global Initiative for Chronic Obstructive Lung Disease (GOLD) criteria or American Thoracic Society (ATS)/European Respiratory Society (ERS) criteria, risk factors, and confounders. Occupational exposures to VGDF were rated according to a specific job-exposure matrix. Adjusted logistic regression models were used to evaluate risk factors for airway obstruction in smokers and nonsmokers. Results: In total, 9.8% had airway obstruction by GOLD criteria and 10.3% by ATS/ERS. Smokers with a high likelihood of exposure to VGDF had a higher risk of airway obstruction than those not exposed (odds ratio [OR]: 1.74, 95% confidence interval [CI]: 1.15–2.65 by GOLD; OR: 1.58, 95% CI: 1.06–2.37 by ATS/ERS) especially those >50 years of age. In smokers highly exposed to VGDF, risk estimates were higher than in the whole population, and the interaction between high exposure to VGDF and smoking further increased the risk of airway obstruction. Conclusions: This study suggests a possible role for interaction between cigarette smoking and VGDF exposure on the risk of airway obstruction

Time to pregnancy among partners of men exposed to di(2-ethylhexyl)phthalate

Objectives This study assessed paternal occupational exposure to di(2-ethylhexyl)phthalate (DEHP) in association with reduced fertility. Methods Men working in three plants with DEHP exposure were studied retrospectively. Male and female employees and their partners were invited to participate if they had reported a pregnancy or an attempt to achieve a pregnancy. Postal questionnaires and telephone interviews were used to collect additional data from the men and women, respectively. Information on time to pregnancy was eligible for 326 pregnancies fathered by 193 men. Male exposure to DEHP during every month of their time to pregnancy was classified into one of three exposure categories. The exposure ranged from 0.5 mg/m(3) during the time to pregnancy. The pregnancies of employed women with unexposed partners or pregnancies of employed men unexposed during the time to pregnancy formed the reference group. Results The fecundability ratio for time to pregnancy was 1.07 [95% confidence interval (95% Cl) 0.84-1.351 for those with low exposure and 0.97 (95% CI 0.70-1.33) for the highly exposed after adjustment for the father's age, mother's age, and length of recall. When the analyses were restricted to first pregnancy, the fecundability ratio was 1.13 (95% Cl 0.83-1.56) for low exposure and 1.02 (95% Cl 0.66-1.59) for high exposure. Conclusions Time to pregnancy is not prolonged among couples with paternal exposure to DEHP at a mean exposure level of <0.5 mg/ml

Occupational exposure to dust and to fumes, work as a welder and invasive pneumococcal disease risk

Objectives Occupational exposures to metal fumes have been associated with increased pneumonia risk, but the risk of invasive pneumococcal disease (IPD) has not been characterised previously. Methods We studied 4438 cases aged 20-65 from a Swedish registry of invasive infection caused by Streptococcus pneumoniae. The case index date was the date the infection was diagnosed. Six controls for each case, matched for gender, age and region of residency, were selected from the Swedish population registry. Each control was assigned the index date of their corresponding case to define the study observation period. We linked cases and controls to the Swedish registries for socioeconomic status (SES), occupational history and hospital discharge. We applied a job-exposure matrix to characterise occupational exposures. We used conditional logistic analyses, adjusted for comorbidities and SES, to estimate the OR of IPD and the subgroup pneumonia-IPD, associated with selected occupations and exposures in the year preceding the index date. Results Welders manifested increased risk of IPD (OR 2.99, 95% CI 2.09 to 4.30). Occupational exposures to fumes and silica dust were associated with elevated odds of IPD (OR 1.11, 95% CI 1.01 to 1.21 and OR 1.33, 95% CI 1.11 to 1.58, respectively). Risk associated with IPD with pneumonia followed a similar pattern with the highest occupational odds observed among welders and among silica dust exposed. Conclusion Work specifically as a welder, but also occupational exposures more broadly, increase the odds for IPD. Welders, and potentially others with relevant exposures, should be offered pneumococcal vaccination

Occupational Exposure and New-onset Asthma in a Population-based Study in Northern Europe (RHINE)

In a large population-based study among adults in northern Europe the relation between occupational exposure and new-onset asthma was studied. The study comprised 13 284 subjects born between 1945 and 1973, who answered a questionnaire 19891992 and again 19992001. Asthma was defined as Asthma diagnosed by a physician with reported year of diagnose. Hazard ratios (HR), for new-onset adult asthma during 19802000, were calculated using a modified job-exposure matrix as well as high-risk occupations in Cox regression models. The analyses were made separately for men and women and were also stratified for atopy. During the observation period there were 429 subjects with new-onset asthma with an asthma incidence of 1.3 cases per 1000 person-years for men and 2.4 for women. A significant increase in new-onset asthma was seen for men exposed to plant-associated antigens (HR 3.6; 95% CI [confidence interval] 1.49.0), epoxy (HR 2.4; 95% CI 1.34.5), diisocyanates (HR 2.1; 95% CI 1.23.7) and accidental peak exposures to irritants (HR 2.4; 95% CI 1.34.7). Both men and women exposed to cleaning agents had an increased asthma risk. When stratifying for atopy an increased asthma risk were seen in non-atopic men exposed to acrylates (HR 3.3; 95% CI 1.47.5), epoxy compounds (HR 3.6; 95% CI 1.67.9), diisocyanates and accidental peak exposures to irritants (HR 3.0; 95% CI 1.27.2). Population attributable risk for occupational asthma was 14% for men and 7% for women. This population-based study showed that men exposed to epoxy, diisocyanates and acrylates had an increased risk of new-onset asthma. Non-atopics seemed to be at higher risk than atopics, except for exposure to high molecular weight agents. Increased asthma risks among cleaners, spray painters, plumbers, and hairdressers were confirmed

The use of household cleaning sprays and adult asthma: an international longitudinal study

Rationale: Cleaning work and professional use of certain cleaning products have been associated with asthma, but respiratory effects of nonprofessional home cleaning have rarely been studied. Objectives: To investigate the risk of new-onset asthma in relation to the use of common household cleaners. Methods: Within the follow-up of the European Community Respiratory Health Survey in 10 countries, we identified 3,503 persons doing the cleaning in their homes and who were free of asthma at baseline. Frequency of use of 15 types of cleaning products was obtained in a face-to-face interview at follow-up. We studied the incidence of asthma defined as physician diagnosis and as symptoms or medication usage at follow-up. Associations between asthma and the use of cleaning products were evaluated using multivariable Cox proportional hazards or log-binomial regression analysis. Measurements and Main Results: The use of cleaning sprays at least weekly (42% of participants) was associated with the incidence of asthma symptoms or medication (relative risk [RR], 1.49; 95% confidence interval [CI], 1.12-1.99) and wheeze (RR, 1.39; 95% CI, 1.06-1.80). The incidence of physician-diagnosed asthma was higher among those using sprays at least 4 days per week (RR, 2.11; 95% CI, 1.15-3.89). These associations were consistent for subgroups and not modified by atopy. Dose-response relationships (P < 0.05) were apparent for the frequency of use and the number of different sprays. Risks were predominantly found for the commonly used glass-cleaning, furniture, and air-refreshing sprays. Cleaning products not applied in spray form were not associated with asthma. Conclusions: Frequent use of common household cleaning sprays may be an important risk factor for adult asthma

Cat and dust mite allergen levels, specific IgG and IgG4, and respiratory symptoms in adults

Proteins administered orally must pass through the gastric environment in order to reach their site of absorption in the intestine. How to protect these exogenously administered proteins from the damaging effects of gastric acid and pepsin proteolytic activity, which often induce irreversible structural and functional alterations to the molecules, is an intriguing challenge. Another problem is the physical and chemical instability of proteins during some technological processes, which often involve the use of organic solvents or high temperatures. In this study we investigated the use of alginate microparticles containing one of two enzymes, an enteric polymer and a lyoprotectant for the intestinal delivery of proteins. The two enzymes tested in this protein delivery system were lactate dehydrogenase and alpha-amylase: the former was chosen because of its sensitivity to denaturation, the latter for its relevance in nutrition and medicine. A sodium alginate aqueous solution containing the enteric polymer, a lyoprotectant and the enzyme was either extruded or sprayed into a calcium chloride solution, with the resultant formation of beads and microspheres which were freeze-dried. About 90% of the enzyme activity was maintained during the process of loading the proteins into the microparticles and the subsequent freeze-drying process. The stability of the encapsulated enzyme in an acid medium and the enzymatic activity in an intestinal environment were then investigated by a dissolution test. This consisted of exposing the microparticles to simulated gastric fluid (pH 1.2) for 2 hours and to simulated intestinal fluid (pH 7.5±0.1) for 1 hour. The morphology of the microparticles did not change in the acid environment, whereas they completely dissolved within 3 min in the simulated intestinal fluid. Residual enzymatic activity after the test remained satisfactory for both enzymes. In conclusion, these microparticle systems offer promise for applications in human and veterinary medicine as well as in human and animal nutrition

Serum-derived exosomes from antigen-fed mice prevent allergic sensitization in a model of allergic asthma

Oral tolerance is an active process that starts with sampling of luminal antigens by the intestinal epithelial cells (IEC), followed by processing and assembly with major histocompatibility complex class II and subsequently a release of tolerogenic exosomes (tolerosomes) from the IEC. We have previously shown that tolerosomes can be isolated from serum shortly after an antigen feed, and will potently transfer antigen-specific tolerance to naive recipients. Here we study the capacity of the tolerosomes to protect against allergic sensitization in a mouse model of allergic asthma. Serum or isolated serum exosomes from tolerized BALB/c donor mice were transferred to syngeneic recipients followed by sensitization and intranasal exposure to ovalbumin (OVA). Blood, bronchoalveolar lavage (BAL) and lymph nodes were sampled 24 hr after the final exposure. The number of eosinophils was counted in BAL fluid and the levels of immunoglobulin E (IgE) and OVA-specific IgE were measured in serum. Mediastinal and coeliac lymph nodes were analysed by flow cytometry. The animals receiving serum from OVA-fed mice displayed significantly lower numbers of airway eosinophils and lower serum levels of total IgE as well as of OVA-specific IgE compared with controls. Moreover, the tolerant animals showed a significantly higher frequency of activated T cells with a regulatory phenotype in both mediastinal and coeliac lymph nodes. The results show that serum or isolated serum exosomes obtained from OVA-fed mice and administered intraperitoneally to naive recipient mice abrogated allergic sensitization in the recipients

The occupational contribution to severe exacerbation of asthma.

The goal of this study was to identify occupational risk factors for severe exacerbation of asthma and estimate the extent to which occupation contributes to these events. The 966 participants were working adults with current asthma who participated in the follow-up phase of the European Community Respiratory Health Survey. Severe exacerbation of asthma was defined as self-reported unplanned care for asthma in the past 12 months. Occupations held in the same period were combined with a general population job-exposure matrix to assess occupational exposures. 74 participants reported having had at least one severe exacerbation event, for a 1-yr cumulative incidence of 7.7%. From regression models that controlled for confounders, the relative risk (RR) was statistically significant for low (RR 1.7, 95% CI 1.1-2.6) and high (RR 3.6, 95% CI 2.2-5.8) biological dust exposure, high mineral dust exposure (RR 1.8, 95% CI 1.02-3.2), and high gas and fumes exposure (RR 2.5, 95% CI 1.2-5.5). The summary category of high dust, gas, or fumes exposure had RR 3.1 (95% CI 1.9-5.1). Based on this RR, the population attributable risk was 14.7% among workers with current asthma. These results suggest occupation contributes to approximately one in seven cases of severe exacerbation of asthma in a working population, and various agents play a role