Background: Indoor air contaminants may act as endocrine-disrupting chemicals (EDCs). However, to what extent these contaminants affect health is poorly known.We aimed to assess the association between EDCs exposure and asthma, respiratory symptoms and obesity in schoolchildren.Methods: Data from a cross-sectional analysis of 815 participants from 20 schools in Porto, Portugal, were analysed. Symptoms were assessed, asthma was defined on lung function, and airway reversibility and body mass index (BMI) were calculated.The concentrations of 13 volatile organic compounds and 2 aldehydes identified as EDCs were measured in 71 classrooms throughout 1 week. Principal component analysis (PCA) was used to assess the effect of co-exposure. Associations were estimated by regression coefficients using linear and logistic regression models.Results: Increased individual and combined EDCs levels were found in classrooms having more children with asthma and obesity. Higher levels of hexane, styrene, cyclohexanone, butylated hydroxytoluene and 2-butoxyethanol were associated with obesity, and higher levels of cyclohexanone were associated with increased child BMI. Toluene, oxylene, m/p-xylene and ethylbenzene were significantly associated with nasal obstruction.A positive association was found between PC1 and the risk of obese asthma (OR = 1.43, 95% CI 1.01, 1.98) and between PC2 and overweight (OR = 1.51, 95% CI 1.28, 1.79).PC1 and PC2 were also associated with nasal obstruction, and PC2 was associated with breathing difficulties and lean body mass, although EDCs concentrations were low. Conclusions:Our findings further support the role of EDCs in asthma and obesity development. Moreover, even low levels of indoor exposure may influence the risk of asthma, respiratory symptoms and obesity.

Detection and quantification of microRNAs (miRNAs) in exhaled breath condensate (EBC) has been poorly explored. Therefore we aimed to assess miRNAs in EBC as potential biomarkers to diagnose and endotype asthma in school aged children. In a cross sectional, nested case control study, all the asthmatic children (n = 71) and a random sample of controls (n = 115), aged 7 to 12 years, attending 71 classrooms from 20 local schools were selected and arbitrarily allocated to the development or validation set. Participants underwent skin-prick testing, spirometry with bronchodilation, had exhaled level of nitric oxide determined and EBC collected. Based on previous studies eleven miRNAs were chosen and analyzed in EBC by reverse transcription-quantitative real-time PCR. Principal component analysis was applied to identify miRNAs profiles and associations were estimated using regression models. In the development set (n = 89) two clusters of miRNAs were identified. After adjustments, cluster 1 and three of its clustered miRNAs, miR-126-3p, miR-133a-3p and miR-145-5p were positively associated with asthma. Moreover miR-21-5p was negatively associated with symptomatic asthma and positively associated with positive bronchodilation without symptoms. An association was also found between miR-126-3p, cluster 2 and one of its clustered miRNA, miR-146-5p, with higher FEF25-75 reversibility. These findings were confirmed in the validation set (n = 97) where two identical clusters of miRNAs were identified. Additional significant associations were observed between miR-155-5p with symptomatic asthma, negative bronchodilation with symptoms and positive bronchodilation without symptoms. We showed that microRNAs can be measured in EBC of children and may be used as potential biomarkers of asthma, assisting asthma endotype establishment.

Swimmers, contrary to runners, experience a worsening of nasal function after training. Although these differences were only significant for postnasal drip, our results provide support to the existence of a "swimming-induced rhinitis" independent of the atopic status of the athlete.

In a previous study, evidence was provided that indoor secondhand tobacco smoke (SHS) air pollution remains high in Lisbon restaurants where smoking is allowed, regardless of the protective measures used. The aim of this study was to determine in these locations the levels of polycyclic aromatic hydrocarbons (PAH) associated with the particulate phase of SHS (PPAH), a fraction that contains recognized carginogens, such as benzo[a]pyrene (BaP). Data showed that restaurant smoking areas might contain PPAH levels as high as 110 ng/m(3), a value significantly higher than that estimated for nonsmoking areas (30 ng/m(3)) or smoke-free restaurants (22 ng/m(3)). The effective exposure to SHS components in restaurant smoking rooms was confirmed as cotinine levels found in workers' urine. Considering that all workers exhibited normal lung function, eventual molecular changes in blood that might be associated with occupational exposure to SHS and SHS-associated PPAH were investigated by measurement of two oxidative markers, total antioxidant status (TAS) and 8-hydroxyguanosine (8-OHdG) in plasma and serum, respectively. SHS-exposed workers exhibited higher mean levels of serum 8-OHdG than nonexposed workers, regardless of smoking status. By using a proteomics approach based on 2D-DIGE-MS, it was possible to identify nine differentially expressed proteins in the plasma of SHS-exposed nonsmoker workers. Two acute-phase inflammation proteins, ceruloplasmin and inter-alpha-trypsin inhibitor heavy chain 4 (ITIH4), were predominant. These two proteins presented a high number of isoforms modulated by SHS exposure with the high-molecular-weight (high-MW) isoforms decreased in abundance while low-MW isoforms were increased in abundance. Whether these expression profiles are due to (1) a specific proteolytic cleavage, (2) a change on protein stability, or (3) alterations on post-translational modification pattern of these proteins remains to be investigated. Considering that these events seem to precede the first symptoms of tobacco-related diseases, our findings might contribute to elucidation of early SHS-induced pathogenic mechanisms and constitute a useful tool for monitoring the effects of SHS on occupationally exposed individuals such as those working in the hospitality industry.