Abbreviations	Definition
PM2.5/PM10/PM1/PM0.1	Particulate matter with diameter ≤ 2.5 μm/10 μm/1 μm/0.1 μm
NO2	Nitrogen dioxide
NO/NOx	Nitric oxide/nitrogen oxides
CO	Carbon monoxide
CO2	Carbon dioxide
O3	Ozone
DE	Diesel exhaust
BC	Black carbon
UFPM	Ultrafine particulate matter
HR	Heart rate
HRV	Heart rate variability
SBP/DBP	Systolic/diastolic blood pressure
VO2/VO2max/VO2peak	Oxygen Uptake/Maximal Oxygen Uptake/Peak Oxygen Uptake
VCO2	Carbon Dioxide Output
VT	Tidal volume
VE	Minute Ventilation
FVC	Forced vital capacity
FEV1	Forced expiratory volume in 1 second
PEF/PEFR	Peak expiratory flow/peak expiratory flow rate
FEF25–75	Forced expiratory flow at 25–75% of the pulmonary volume
RV	Residual volume
SpO2	Peripheral Oxygen Saturation
FeNO/eNO	Fraction of Exhaled Nitric Oxide
NO3−	Nitrate
IL-xx	Interleukins (e.g., IL-1β, IL-6, IL-8)
VEGF	Vascular Endothelial Growth Factor
TNF-α	Tumor Necrosis Factor Alpha
GM-CSF	Granulocyte–macrophage colony-stimulating factor
NE	Norepinephrine
MVF/FMD	Microvascular function/flow-mediated dilation
sICAM-1/sVCAM-1/sP-Selectin	Soluble Intercellular/Vascular Cell Adhesion Molecules/Selectin P
EBC	Exhaled breath condensate
CRAE/CRVE	Central retinal arteriolar/venular equivalents
FBF	Forearm blood flow
AMC	Airway macrophage carbon
PRISMA	Preferred Reporting Items for Systematic Reviews and Meta-Analyses
PICO	Patient, Intervention, Comparison, Outcome (framework for research questions)