Exposure to Air Pollution - A Novel Staircase-Function Response Mechanism of Stress Restoration

Introduction: Given the epidemiological facts that exposure to air pollution induce the stress, reasonable hypothesis is made that it also hampers the stress restoration and further cause the mental health concerns. However, no studies examined the specific mechanisms so far.Methods: We adopted an environmental physio-psychological experiment paradigm of stress recovery to investigate the question. The experiment had three steps:(1) After entering the lab and sit in front of a computer monitor, participants were asked to relax for 1 minute.(2) Participants then took 10-minutes oral English tasks in the form of TOEFL test for evoking the stress.(3) Immediately after the stress evocation, 110 participants were randomly divided into seven groups. Then they were asked to relax for 3 minutes in the front of the monitor that displayed one group of blank pictures and six target groups of air pollution pictures with PM2.5 concentrations ranging from 11, 32, 51, 108, 165, to 231 μg/m3, respectively.During the...