PM2.5	Particulate matter with aerodynamic equivalent diameter less than or equal to 2.5 microns in ambient air
V	Vanadium
Cr	Chromium
Mn	Manganese
Co	Cobalt
Ni	Nickel
Cu	Copper
Zn	Zinc
As	Arsenic
Cd	Cadmium
Pb	Lead
DR	Dongfeng East Road sampling site
JDM	Jinding mountain sampling site
WM	West mountain sampling site
SD	Standard deviation
ICP-MS	Inductively coupled plasma mass spectrometry
AMSL	Above mean sea level
CRM	Certified reference materials
EF	Enrichment factor
PCA	Principal component analysis
EPA	U.S Environmental Protection Agency
HRA	Health risk assessment
IRIS	Integrated Risk Information System
IARC	International Agency for Research on Cancer
NOAA	National Oceanic and Atmospheric Administration
ARL	Air Resources Laboratory
BOM	Bureau of Meteorology
NCEP	National Centers for Environmental Prediction
GDAS	Global Data Assimilation System