Table 2.

Mean Concentrations of pollutants during the 2-h walk in the two visits

Pollutants	Concentration (Min-Max, SD)
PM2.5, μg/m3	204.0 (101.0–326.6, 58.5)
CO, ppm	3.6 (1.5–6.1, 1.3)
O3, ppb	5.4 (0.1–36.1, 8.2)
SO2, ppb	37.2 (14.0–69.0, 15.1)
NO, ppb	65.5 (30.0–290.0, 51.2)
NOx, ppb	122 (46.5–563.5, 57.4)
Temperature, °C	0.3 (−2–3,1.56)
Relative Humidity,%	58.3 (38–81,16.6)

PM2.5 particulate matter with aerodynamic diameter less than 2.5 μm, CO carbon monoxide, O3 ozone, SO2 sulfur dioxide, NO nitric oxide, NOx nitrogen oxides