PRELIMINARY PUBLIC HEALTH ASSESSMENT
NORTH SANITARY LANDFILL - DAYTON
DAYTON, MONTGOMERY COUNTY, OHIO
Comparison value for noncarcinogens
Calculations for Chemicals that do not cause cancer:
Comparison Value = (U.S. EPA RfD x Body Weight) ÷ Ingestion Rate
Exposure Dose = (Medium Concentration x intake rate x exposure factor) ÷ Body Weight
Medium Concentration = the concentration of the chemical in water or soil.
Intake Rate = The amount of water or soil a person would drink or eat.
Exposure Factor = Ratio describing exposure other than daily. No exposure factor is used if the exposure occurs daily.
Body Weight = The amount a person weights. Generally 70 kilograms is used for an adult and 10-15 kilograms for a child.
Calculation of risk for those chemicals that may cause cancer:
Comparison Value = (Risk x Body Weight) ÷ (Slope Factor x Ingestion Rate)
Lifetime Excess Cancer Risk =
Annual exposure dose x slope factor x exposure factor in years
Dose is in mg/kg/day
Slope factor = The U.S.EPA cancer slope factor, (mg/kg/day)-1
Exposure factor = A ratio of the amount of time in years that a person would be exposed to the specific chemical to a standard 70 year lifetime.