Occupational exposure to environmental tobacco smoke in hospitality venues: are genetic- or proteomics-based biomarkers predictive of respiratory diseases?

Environmental tobacco smoke (ETS) is recognized as an occupational hazard in the hospitality industry. Although Portuguese legislation banned smoking in most indoor public spaces, it is still allowed in some restaurants/bars, representing a potential risk to the workers’ health, particularly for chronic respiratory diseases. The aims of this work were to characterize biomarkers of early genetic effects and to disclose proteomic signatures associated to occupational exposure to ETS and with potential to predict respiratory diseases development. A detailed lifestyle survey and clinical evaluation (including spirometry) were performed in 81 workers from Lisbon restaurants. ETS exposure was assessed through the level of PM 2.5 in indoor air and the urinary level of cotinine. The plasma samples were immunodepleted and analysed by 2D-SDSPAGE followed by in-gel digestion and LC-MS/MS. DNA lesions and chromosome damage were analysed innlymphocytes and in exfoliated buccal cells from 19 cigarette smokers, 29 involuntary smokers, and 33 non-smokers not exposed to tobacco smoke. Also, the DNA repair capacity was evaluated using an ex vivo challenge comet assay with an alkylating agent (EMS). All workers were considered healthy and recorded normal lung function. Interestingly, following 2D-DIGE-MS (MALDI-TOF/TOF), 61 plasma proteins were found differentially expressed in ETS-exposed subjects, including 38 involved in metabolism, acute-phase respiratory inflammation, and immune or vascular functions. On the other hand, the involuntary smokers showed neither an increased level of DNA/chromosome damage on lymphocytes nor an increased number of micronuclei in buccal cells, when compared to non-exposed non-smokers. Noteworthy, lymphocytes challenge with EMS resulted in a significantly lower level of DNA breaks in ETS-exposed as compared to non-exposed workers (P<0.0001) suggestive of an adaptive response elicited by the previous exposure to low levels of ETS. Overall, changes in proteome may be promising early biomarkers of exposure to ETS. Likewise, alterations of the DNA repair competence observed upon ETS exposure deserves to be further understood. Work supported by Fundação Calouste Gulbenkian, ACSS and FCT/Polyannual Funding Program.

Indoor air quality in schools and its relationship with children's respiratory symptoms

A cross-sectional survey was conducted to characterize the indoor air quality (IAQ) in schools and its relationship with children's respiratory symptoms. Concentrations of volatile organic compounds (VOC), aldehydes, PM2.5, PM10, carbon dioxide, bacteria and fungi were assessed in 73 classrooms from 20 public primary schools located in Porto, Portugal. Children who attended the selected classrooms (n = 1134) were evaluated by a standardised health questionnaire completed by the legal guardians; spirometry and exhaled nitric oxide tests. The results indicated that no classrooms presented individual VOC pollutant concentrations higher than the WHO IAQ guidelines or by INDEX recommendations; while PM2.5, PM10 and bacteria levels exceeded the WHO air quality guidelines or national limit values. High levels of total VOC, acetaldehyde, PM2.5 and PM10 were associated with higher odds of wheezing in children. Thus, indoor air pollutants, some even at low exposure levels, were related with the development of respiratory symptoms. The results pointed out that it is crucial to take into account the unique characteristics of the public primary schools, to develop appropriate control strategies in order to reduce the exposure to indoor air pollutants and, therefore, to minimize the adverse health effects.