Oxidative Stress Biomarkers to Monitor and Early Detect Health Impairment in Workers Exposed to Silica (Caesar Stone)

Study participants would be recruited during two years of the study. They will be asked to come to a single visit at Pulmonary Laboratory of Tel Aviv Medical Center. During the meeting, participants will be given a precise explanation about the tests they will perform and after signing the informed consent will perform following tests: 1. Induced sputum (IS) - will be done after pretreatment with short acting beta-2 agonist and 3% saline will be administrated by an ultrasonic nebulizer for up to 20 min. Differential cell count, particle size distribution test of the particulate matter (with a Eyetech Analyzer (Ankersmid, Yokneam, Israel)will be done from IS samples and evaluation the activity of Heme oxygenase 1 (HO-1) protein from IS supernatants. 2. EBC-Exhaled Breath Condensate-will be done by condensation expiratory air and particulate matter and markers of oxidation will be measured. 3. Participants will be asked to complete occupational questionnaire. 4. Pulmonary function tests (PFTs): The measurement will be performed using standard protocols according to American Thoracic Society/European Respiratory Society (ATS/ERS) guidelines. Including Lung diffusion testing. Laboratory tests of induced sputum and EBC will be done within a week of a participant visit. Analysis of data will be done after the completion of data collection and laboratory tests.