In-car and near-road exposure to PM2.5 and BC

Abstract

The current study aims to characterize the PM2.5 and the equivalent black carbon (eBC) inside/outside vehicles (hereafter called "in/out-cabin") and near roadway, and to estimate their personal exposure to the driver himself as well as the school-aged children. Based on the DoseDEP of a mouse reaching the 90% polymorphonuclear leukocytes (PMNs90%) (Stoeger et al., 2006), the time (day) to reaching the PMNs90% in the blood of a male resident who lives around the roadway was newly calculated. Five independent measurements of PM2.5 and eBC were intensively taken in May 2019 using the monitors attached to the interior and exterior of the vehicle, respectively. In-cabin and out-cabin PM2.5 on the course of driving measurement ranged from 29.4-47.4 μg/m3 with an average of 34.4 μg/m3 and 32.5-56.0 μg/m3 with an average of 45.6 μg/m3, respectively. The eBC in/out-cabin ratio during idling on a busy road ranged from 22% to 86% depending on the windows open/close and ventilation on/off. The in-cabin DosePM2.5 (ng) for 30 seconds on the test driving route ranged from 166-240 ng with an average of 190.4 ng. The average in-school DosePM2.5 (μg) for the schoolchild attending the school near a bus stop is 1.2 times higher than that of schoolchild attending the school away from a bus stop. The time (day) to reaching the PMNs90% due to DEP inhalation for the male resident who lives around the roadway was estimated as 113 days.