Elimination kinetics of diisocyanates after specific inhalative challenges in humans: mass spectrometry analysis, as a basis for biomonitoring strategies

Background: Isocyanates are some of the leading occupational causes of respiratory disorders, predominantly asthma. Adequate exposure monitoring may recognize risk factors and help to prevent the onset or aggravation of these aliments. Though, the biomonitoring appears to be most suitable for exposure assessment, the sampling time is critical, however. In order to settle the optimal time point for the sample collection in a practical biomonitoring approach, we aimed to measure the elimination of isocyanate urine metabolites. Methods: A simple biomonitoring method enabling detection of all major diamine metabolites, from mono-, poly- and diisocyanates in one analytical step, has been established. Urine samples from 121 patients undergoing inhalative challenge tests with diisocyanates for diagnostic reasons were separated by gas chromatography and analyzed with mass spectrometry (GC-MS) at various time points (0-24 h) after the onset of exposure. Results: After controlled exposures to different concentrations of diisocyanates (496 +/- 102 ppb-min or 1560 +/- 420 ppb-min) the elimination kinetics (of respective isocyanate diamine metabolites) revealed differences between aliphatic and aromatic isocyanates (the latter exhibiting a slower elimination) and a dose-response relationship. No significant differences were observed, however, when the elimination time patterns for individual isocyanates were compared, in respect of either low or high exposure or in relation to the presence or absence of prior immunological sensitization. Conclusions: The detection of isocyanate metabolites in hydrolyzed urine with the help of gas chromatography combined with mass spectrometric detection system appears to be the most suitable, reliable and sensitive method to monitor possible isocyanate uptake by an individual. Additionally, the information on elimination kinetic patterns must be factored into estimates of isocyanate uptake before it is possible for biomonitoring to provide realistic assessments of isocyanate exposure. The pathophysiological elimination of 1,6-hexamethylene diamine, 2,4-diamine toluene, 2,6-diamine toluene, 1,5-naphthalene diamine, 4,4'-diphenylmethane diamine and isophorone diamines (as respective metabolites of: 1,6-hexamethylene diisocyanate, 2,4-toluene diisocyanate and 2,6 toluene diisocyanate, 1,5-naphthalene diisocyanate, 4,4'-diphenylmethane diisocyanate and isophorone diisocyanates) differs between individual isocyanates' diamines

Evaluation of Long-Term Respiratory Effects of Exposure to Welding Fumes

Abstract Welding fumes are known to cause respiratory health problems. We aimed to evaluate the long-term respiratory effects of exposure to welding fumes. Inception cohorts of welding, plumbing, and heating apprentices were prospectively contacted 7-17 years post-apprenticeship. Questionnaires, as well as spirometry and non-specific bronchial hyperresponsiveness (NSBHR) tests were repeatedly administered. A long-term evaluation was done in 71 former apprentices at the Hôpital du Sacré-Cœur de Montréal between 2013 and 2017. Post-apprenticeship exposure to welding fumes and gasses was evaluated using three methods: self-report, expert assessment and the asthmaspecific job exposure matrix. The incidence of wheezing and excessive lung function decline, given continued post-apprenticeship exposure to welding fumes, was estimated using Cox regression. Incident wheezing was found in 18.8% of subjects, and excessive lung function decline was observed in 12.7% of subjects. All three exposure assessment methods consistently showed that subjects with continued, post-apprenticeship exposure to welding fumes or gasses had a lower risk of developing wheezing symptoms or excessive decline in lung function, although none of the associations were significant. In conclusion, continued post-apprenticeship exposure to welding fumes does not seem to increase the risk of developing long-term respiratory outcomes.Keywords: apprentices, lung function, occupational, welding Abstrak Asap dan gas pengelasan (welding fumes and gasses) diketahui dapat menyebabkan masalah pernapasan. Penelitian ini dilakukan untuk mengevaluasi efek pernapasan jangka panjang dari pajanan asap dan gas pengelasan. Mantan peserta sekolah kejuruan pengelasan secara prospektif dihubungi 7-17 tahun pasca-pendidikan. Subjek penelitian melengkapi kuesioner, uji spirometri dan uji bronkus non-spesifik. Evaluasi jangka panjang dilakukan pada 71 subjek di Hôpital du Sacré-Cœur de Montréal antara tahun 2013 dan 2017. Pajanan asap dan gas pengelasan pascapendidikan dievaluasi menggunakan tiga metode: laporan oleh pekerja, penilaian oleh ahli dan penggunaan matriks pajanan di tempat kerja pekerjaan khusus. Hubungan antara pajanan asap dan gas pengelasan dengan insidens mengi dan penurunan fungsi paru-paru berlebihan dievaluasi menggunakan regresi Cox. Insidens mengi ditemukan pada 18,8% subjek, dan penurunan fungsi paru berlebihan diamati pada 12,7% subjek. Ketiga metode penilaian pajanan secara konsisten menunjukkan bahwa subjek dengan pajanan asap dan gas pengelasan pasca-pendidikan memiliki risiko lebih rendah terkena gejala mengi atau penurunan fungsi paru-paru yang berlebihan, meskipun tidak ada hubungan yang bermakna. Sebagai kesimpulan, pajanan asap dan gas pengelasan jangka panjang tampaknya tidak meningkatkan risiko penurunan fungsi pernapasan.Kata kunci: fungsi paru, pekerjaan, asap dan gas pengelasa

Polar polycyclic aromatic compounds (polar PACs) occurence and origin : issues and requirements for future investigations

International audiencePolar polycyclic aromatic compounds (polar PACs) are less known than PAHs, and neither monitored nor regulated anywhere, despite their potential harmfulness and greater mobility. They were rarely intentionally produced, and they occur mainly as PAH metabolites. They often occur at the same sites (gasworks, coke plants, wood treatment sites) as PAHs and other PACs but have been mostly overlooked. Other potential sites include wood tar production and oil refineries or storage affected by accidents. PAH remediation treatments, such as thermal desorption or chemical oxidation may have promoted the formation of oxy-PACs while applied, along with the mitigation of regulated PAHs. According to existing regulations, the site contamination level related to the sum of PAH was reduced, but the actual risk may have been increased. In order to identify potential risks, the monitoring of oxy-PACs is required. However, analytical capabilities are not developed, data on oxy-PACs are scarce and research is still needed. Available results from contaminated site databases and from our investigations suggest that polar PACs may constitute between 10 and 20% of total PACs in soil, and their occurrence in shallow groundwater is often overlooked at contaminated sites. Their potential impact on risk analysis is largely unknown and may be underestimated, as their transfer properties are by far less favourable than those of PAHs. Their monitoring would require analysis standards and commercially available analytical services before any regulatory approach is undertaken. This is most important for sustainable remediation of PAH-contaminated sites

Association between patterns of leisure time physical activity and asthma control in adult patients

Background Physical activity has been shown to have various health benefits in patients with asthma, especially in children. However, there are still limited data on the nature of the association between physical activity and asthma control in adults. Objective The objective of the current study was to determine the nature of the association between physical activity and asthma control, with particular emphasis on the intensity of the activity and seasonal variations. Methods 643 adult patients with objectively confirmed asthma (mean age (SD)=53 (15) years, 60% women) were interviewed by telephone. Patients completed the asthma control questionnaire (ACQ), the asthma quality of life questionnaire, and a 1-year physical activity recall questionnaire to assess leisure time physical activity (LTPA). Results Total LTPA was related to control (β (95% CI)=−0.013 (−0.030 to 0.006)), with those doing recommended levels of LTPA being nearly 2.5 times more likely to have good control compared with inactive patients. Analysis of seasonal exercise habits found that winter LTPA (β=−0.027 (−0.048 to −0.006)) was more strongly associated with ACQ scores than summer LTPA (β=−0.019 (−0.037 to −0.001)). Adjustment for age, sex, season of assessment, inhaled corticosteroid (ICS) dose, body mass index, and current smoking status reduced the strength of the relationships. Conclusions Data indicate that higher levels of LTPA are associated with better levels of asthma control in adult patients with asthma, and that this seems to be more pronounced among asthmatics who do the recommended levels of exercise

Effect of remediation treatments on Polar PACs in soils : degradation vs. formation

International audienceThe evaluation of the efficiency of remediation processes (thermal desorption, ISCO, bioremediation…) of PAH polluted soil is generally based on the measurement of specific parameters (i.e. 16 PAH US-EPA). Such limited characterisations do not allow evaluating the potential formation of organic by-products (especially Polycyclic Aromatic Compounds-PAC). Different remediation treatments, most commonly used and that may be the most problematic regarding O-PAH production, have been applied to three representatives PAH contaminated soils (former gasworks, coke oven plants and wood preservation facilities soils). These treatments include chemical oxidation (hydroperoxyde oxidation (H 2 O 2), Fenton like oxidation using magnetite as catalyst and permanganate (MnO 4-)) and biological treatment. The experimental results with chemical treatment show that the polar oxy-PAHs were removed more slowly than the PAHs in all chemical treatments, indicating that O-PACs were simultaneous generated during the oxidation (especially for permanganate treatment). The effect was most obvious when considering the PAC contribution to the total Extractable Organic Matter (EOM). The microbiological treatment performed on these soils shows a removal of PAHs with a removal rates controlled by the availability of the pollution. Polar PACs remediation followed the same trends as the PAHs in the coke oven soils and the gasworks soil. However, in the wood preservation soil, the removal rates of the polar PACs were significantly lower than of the PAHs suggesting a simultaneous formation of polar PACs as a result of the extensive transformation of PAHs in this soil

Cigarette Smoking and Asthma: A Dangerous Mix

In Canada, 20% to 30% of the general population currently smoke. Smoking is as common in those suffering from asthma as it is in the general population. However, most studies on the pathophysiology of asthma and its response to treatment only include nonsmokers. Available data that examine the influence of smoking on clinical, functional and inflammatory characteristics of asthma, as well as the influence of smoking on the therapeutic response to corticosteroids, were reviewed. Active smoking is associated with an increased morbidity from asthma and impairs the response to inhaled corticosteroids. These observations emphasize the need for smoking cessation in patients with asthma and for reassessment of current treatment guidelines in this population

Barriers to the recognition and reporting of occupational asthma by Canadian pulmonologists

BACKGROUND: Occupational asthma is a common, but probably under-recognized problem

Outcome of Occupational Asthma after Removal from Exposure: A Follow-Up Study

BACKGROUND: Despite being removed from their workplace, the majority of workers with occupational asthma (OA) remain afflicted with asthma

Besoins de santé des mineurs non accompagnés - L’expérience d’une consultation d’adolescents à Genève

This article addresses the health needs of unaccompanied undocumented minors (UMs) received in Geneva. In our experience and according to the literature, the most frequent diagnoses in this population are depression, anxiety disorder, posttraumatic stress disorder and substance abuse. Their medical and psychological treatments are often complicated by their psychosocial difficulties as well as by their wandering. Their treatment should be given by a multidisciplinary care team that works with the different structures that support them both socially and administratively. The adolescent health unit of the Geneva University Hospital give them the opportunity to reclaim their physical and mental health. It also enables them to bond with others and rethink their future trajectories.Cet article propose d’aborder les besoins de santé des mineurs non accompagnés non requérants d’asile accueillis à Genève. Dans notre expérience et selon la littérature, les diagnostics les plus fréquents dans cette population sont les troubles anxio­dépressifs, l’état de stress post-traumatique et les abus de substances. Leur prise en charge, souvent compliquée par leurs difficultés psychosociales et leur errance, devrait se faire par une équipe pluridisciplinaire de soins ainsi qu’en réseau avec les différentes structures qui les soutiennent sur le plan social et administratif. L’Unité santé jeunes (USJ) des Hôpitaux universitaires de Genève leur propose des espaces pour se réapproprier leur santé tant physique que psychique, afin de leur donner la possibilité de se lier à l’autre et de repenser leur errance