A concept of risk apportionment of air emission sources for risk reduction considerations

Receptor and dispersion modeling techniques are extended to develop a health risk apportionment concept in which inhalation exposure to emission sources of ambient element pollutants are estimated. A preliminary demonstration of the concept is performed using ambient and emission inventory data from an industrial air shed located in a residential area. It is shown that risks from identified emission sources can be quantified and that a total, additive risk can be estimated for the sources in the air shed. Potential risk reduction measures can then be considered on the main risk sources without arbitrarily reducing risk for all existing sources in the air shed. Dispersion modeling is utilized from emission inventory data so that risk estimates for the primary sources can be modeled and compared with both ambient and receptor model risk estimates.