Air-vegetation-soil partitioning of toxic chemicals in environmental simulation modeling

Accumulation of airborne pollutants in vegetation is an important initial step in the uptake process of
the terrestrial food web, providing direct and indirect routes by which biota and, eventually, humans
are exposed to chemicals. A set of algorithms for estimating atmospheric pollutant interactions in soilvegetation-
air systems is developed and tested. The model incorporates significant transport pathways
with appropriate parameterization and requires a relatively limited number of meteorological input
data and pollutant characteristics and vegetation parameters. Testing applications include model comparison
to field data in the cases of cadmium in grass and six polycyclic aromatic hydrocarbons (PAH)
in maple leaves. Results indicate that the model provides a reasonable compromise between model
complexity and the ability to obtain realistic data characterizing model parameters. It is well suited for
screening-level assessments; and it can also be used as a component of a management-oriented and
multimedia-based environmental assessment of atmospheric pollutants. On-going work is incorporating
the model algorithms into a multimedia simulation framework to provide better capabilities.