Effects of environmental noise pollution on perceived stress and cortisol levels in street vendors

The present study describes and analyzes experimental results of a study performed with street vendors exposed to noise pollution by monitoring daily variations in cortisol levels taking into account the influence of variables such as age and body mass index (BMI). The study was conducted with 17 male street vendors, inhabitants of Uberlandia - Brazil, who work in the central region of the city. The levels of exposure to noise were assessed using an audio dosimeter and, every two hr, samples of saliva were collected for determination of salivary cortisol levels through an enzymatic immunoassay. The measured equivalent A-weighted sound level (LAeq) ranged from 70.2 to 76.6 dB (A) during the monitoring period of endogenous salivary cortisol levels. Morning levels of cortisol in street vendors were higher in older and overweight individuals. The noise levels to which the subjects were exposed were above the acoustic comfort threshold established by the World Health Organization and hence may be associated with severe discomfort and stress