Comparison of oxidative properties, light absorbance, total and elemental mass concentration of ambient PM2.5 collected at 20 European sites.

OBJECTIVE: It has been proposed that the redox activity of particles may represent a major determinant of their toxicity. We measured the in vitro ability of ambient fine particles [particulate matter with aerodynamic diameters<or=2.5 microm (PM2.5)] to form hydroxyl radicals (.OH) in an oxidant environment, as well as to deplete physiologic antioxidants (ascorbic acid, glutathione) in the naturally reducing environment of the respiratory tract lining fluid (RTLF). The objective was to examine how these toxicologically relevant measures were related to other PM characteristics, such as total and elemental mass concentration and light absorbance. DESIGN: Gravimetric PM2.5 samples (n=716) collected over 1 year from 20 centers participating in the European Community Respiratory Health Survey were available. Light absorbance of these filters was measured with reflectometry. PM suspensions were recovered from filters by vortexing and sonication before dilution to a standard concentration. The oxidative activity of these particle suspensions was then assessed by measuring their ability to generate .OH in the presence of hydrogen peroxide, using electron spin resonance and 5,5-dimethyl-1-pyrroline-N-oxide as spin trap, or by establishing their capacity to deplete antioxidants from a synthetic model of the RTLF. RESULTS AND CONCLUSION: PM oxidative activity varied significantly among European sampling sites. Correlations between oxidative activity and all other characteristics of PM were low, both within centers (temporal correlation) and across communities (annual mean). Thus, no single surrogate measure of PM redox activity could be identified. Because these novel measures are suggested to reflect crucial biologic mechanisms of PM, their use may be pertinent in epidemiologic studies. Therefore, it is important to define the appropriate methods to determine oxidative activity of PM

FATIGUE RESISTANCE OF ADHESIVE BONDED CONNECTIONS WITH AND WITHOUT INTERNAL STEEL PLATES IN LARGE TIMBER STRUCTURES

A modular wooden wind turbine tower has been developed by the Swedish company Modvion AB, where the prefabricated modular elements are connected by glued timber-timber edge joints and by hybrid timber joints with bonded-in perforated steel plates. The application of wood-based products in such a demanding application and high-performance structure is challenging and a variety of questions had to be solved to ensure a reliable performance. The fatigue performance of the adhesive bonded connections has been evaluated in a research project and is presented in this paper. Test specimens of the fatigue resistance of the adhesive and the bond line has been developed. Different stress ratios with alternating loads and high numbers of load cycles have been tested. The results of the tests are presented in this paper

Inhalation incidents and respiratory health: results from the European Community Respiratory Health Survey.

Background Inhalation incidents are an important cause of acute respiratory symptoms, but little is known about how these incidents affect chronic respiratory health. Methods We assessed reported inhalation incidents among 3,763 European Community Respiratory Health Survey (ECRHS) participants with and without cough, phlegm, asthma, wheezing or bronchial hyperresponsiveness. We then examined whether inhalation incidents during the 9-year ECRHS follow-up period were associated with a new onset of any of these respiratory outcomes among 2,809 participants who were free of all five outcomes at the time of the baseline ECRHS survey. Results Inhalation incidents were reported by 5% of participants, with higher percentages reported among individuals with asthma-related outcomes at the time of the baseline survey. Among participants without symptoms at baseline, our analyses generated non-statistically significant elevated estimates of the risk of cough, phlegm, asthma and wheezing and a non-statistically significant inverse estimate of the risk of bronchial hyperresponsiveness among participants who reported an inhalation incident compared to those without such an event reported. Discussion Our findings provide limited evidence of an association between inhalation incidents and asthma-related symptoms. These data could be affected by differences in the reporting of inhalation incidents according to symptom status at the time of the baseline survey; they should thus be interpreted with caution

Early-life risk factors and incidence of rhinitis: Results from the European Community Respiratory Health Study-an international population-based cohort study.

BACKGROUND: Rhinitis is an increasingly common condition with a heavy health care burden, but relatively little is known about its risk factors. OBJECTIVE: To examine the association between early-life factors and the development of rhinitis in the European Community Respiratory Health Study (ECRHS). METHODS: In 1992-1994, community-based samples of 20-44-year-old people were recruited from 48 centers in 22 countries. On average, 8.9 years later, 28 centers reinvestigated their samples. Onset of rhinitis was reported by 8486 participants in interviewer-led questionnaires. Cox regression was used to assess independent predictors of rhinitis at ages 645, 6-10, 11-20, and 6521 years. RESULTS: The crude lifelong incidence of rhinitis was 7.00/1000/year (men) and 7.95/1000/year (women) (P = .002). Women developed less rhinitis in later childhood (hazard ratios [HR], 0.63; 95% CI, 0.47-0.85) and more rhinitis in adulthood (HR, 1.36; 95% CI, 1.11-1.66) than did men. In atopic subjects, siblings were associated with lower risk of rhinitis throughout life (pooled HR, 0.94; 95% CI, 0.91-0.98 per 1 sibling). Early contact with children in the family or day care was associated with less incidence of rhinitis, predominantly before age 5 years (HR, 0.84; 95% CI, 0.72-0.99). Early childhood pets or growing up on a farm was associated with less incidence of rhinitis in adolescence (HR, 0.50; 95% CI, 0.37-0.68). Combining these factors showed evidence of a dose-response relationship (trend P = .0001). CONCLUSIONS: Gender is a strong risk factor for rhinitis, with age patterns varying according to atopic status. Protective effects of early contact with children and animals were suggested for incident rhinitis, with risk patterns varying by age window and atopic status

The occupational contribution to severe exacerbation of asthma.

ABSTRACT: 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\u20132.6) and high (RR 3.6, 95% CI 2.2\u20135.8) biological dust exposure, high mineral dust exposure (RR 1.8, 95% CI 1.02\u20133.2), and high gas and fumes exposure (RR 2.5, 95% CI 1.2\u20135.5). The summary category of high dust, gas, or fumes exposure had RR 3.1 (95% CI 1.9\u20135.1). 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

Exposure to substances in the workplace and new-onset asthma: an international prospective population-based study (ECRHS-II).

Summary Background The role of exposure to substances in the workplace in new-onset asthma is not well characterised in population-based studies. We therefore aimed to estimate the relative and attributable risks of new-onset asthma in relation to occupations, work-related exposures, and inhalation accidents. Methods We studied prospectively 6837 participants from 13 countries who previously took part in the European Community Respiratory Health Survey (1990\u201395) and did not report respiratory symptoms or a history of asthma at the time of the fi rst study. Asthma was assessed by methacholine challenge test and by questionnaire data on asthma symptoms. Exposures were defi ned by high-risk occupations, an asthma-specifi c job exposure matrix with additional expert judgment, and through self-report of acute inhalation events. Relative risks for new onset asthma were calculated with log-binomial models adjusted for age, sex, smoking, and study centre. Findings A signifi cant excess asthma risk was seen after exposure to substances known to cause occupational asthma (Relative risk=1\ub76, 95% CI 1\ub71\u20132\ub73, p=0\ub7017). Risks were highest for asthma defi ned by bronchial hyper-reactivity in addition to symptoms (2\ub74, 1\ub73\u20134\ub76, p=0\ub7008). Of common occupations, a signifi cant excess risk of asthma was seen for nursing (2\ub72, 1\ub73\u20134\ub70, p=0\ub7007). Asthma risk was also increased in participants who reported an acute symptomatic inhalation event such as fi re, mixing cleaning products, or chemical spills (RR=3\ub73, 95% CI 1\ub70\u201311\ub71, p=0\ub7051). The population-attributable risk for adult asthma due to occupational exposures ranged from 10% to 25%, equivalent to an incidence of new-onset occupational asthma of 250\u2013300 cases per million people per year. Interpretation Occupational exposures account for a substantial proportion of adult asthma incidence. The increased risk of asthma after inhalation accidents suggests that workers who have such accidents should be monitored closely