Abbreviation	Meaning
Abs	Absorption Rate
ADAF	Age-Dependent Adjustments Factor
ADD	Average Daily Dose
AT	Averaging Exposure Time
CPD	Cigarette per Day
ECR	Excess Lifetime Cancer Risk
ED	Exposure Duration
EF	Exposure Frequency
ETS	Exposure to Environmental Tobacco Smoke
FCTC	Framework Convention on Tobacco Control
HC	Health Canada
HI	Hazard Index
HPLC MS/MS	High-Performance Liquid Chromatography-Tandem Mass Spectroscopy
HQ	Hazard Quotient
I-EDI	Internal Estimated Daily Intake
IR	Inhalation Ratio
ISO	International Organization for Standardization
IUR	Inhalation Unit Risk
KNHANES	Korea National Health and Nutrition Examination Survey
LADD	Lifetime Average Daily Dose
NNAL	4-(Methylnitrosamino)-1-(3-Pyridyl)-1-Butanol
RfC	Reference Concentration
SHS	Second-hand Smoke
THS	Third-hand Smoke
TSNAs	Tobacco-specific Nitrosamines
WHO	World Health Organization