Introduction:
Peak expiratory flow (PEF), a measure of lung function, was first described by Hadorn in 1942. The definition of PEF, written by the European Respiratory Society, states that it is the maximum flow achieved during the expiration phase, delivered with maximal force, starting from the maximum level of lung inflation. The aim of this study was to evaluate the variations of PEF associated with height, age, body surface area, place of residence and environmental factors among healthy adults in an urban setting in Poland.

Material and methods:
The study comprised 88 healthy, non-smoking subjects: 30 females and 58 males, aged 20–80 years. Epidemiological and demographic data were collected from each participant, as well as information on symptoms and the occurrence of lung diseases. Only healthy subjects were selected for analysis. Participants completed spirometry testing; physical parameters were measured, and appropriate additional data obtained.

Results:
Among the study group of 88 participants (30 females and 58 males), peak expiratory flow rate was negatively correlated with age (p = 0.000001), and positively correlated with height and body surface area (both p < 0.000001). There was a significant negative correlation between PEF and longitudinal environmental factors such as different particulate matter levels (p = 0.0007) present at the place of residence.

Conclusions:
Peak expiratory flow changes are present in a healthy adult population. Place of residence and environmental factors influence the results of spirometry tests.