ARPA	Regional Agency for the Environmental Protection
AT	Averaging time
CA	Concentration in air
EC	Exposure Concentration
ED	Exposure duration
EF	Exposure frequency
ET	Exposure time
HQ	Hazardous Quotient
ICR	Increased Cancer Risk
IRIS	Integrated Risk Information System
IUR	Inhalation Unit Risk
MAPEC	Monitoring Air Pollution Effects on Children for Supporting Public Health Policy
PAH	Polycyclic Aromatic Hydrocarbon
PM	Particulate Matter
RfC	Reference concentration
UCL	Upper Confidence Limit
USEPA	United States Environmental Protection Agency
WHO	World Health Organization