Environmental Factor and Onset of Spontaneous Pneumothorax

Inclusion Criteria: * age over 18 years * first episode of primary spontaneous pneumothorax Exclusion Criteria: * Patients with traumatic * Patients with secondary pneumothorax * Patients with recurrent pneumothorax and patients with short-term readmissions (recurrence was defined as a new ED admission for the same diagnosis more than 14 days after the first admission).