MODELING VOLATILIZATION OF PCDD F FROM SOIL AND UPTAKE INTO VEGETATION/

Soil contamination is one of the long-term environmental problems gene rated by anthropogenic activities of the last decades. Standards for s ome organic compounds are being discussed. We investigated the questio n of whether volatilization of organic chemicals-here PCDD/F-from soil and subsequent sorption to leaves may be a significant pathway for co ntamination. This transfer pathway is investigated with a mathematical model. The model is based on an analytical solution of the diffusion/ dispersion equation for two media and equilibrium assumptions. A calcu lation is made for 2,3,7,8-TCDD uptake into herbage. It can be shown t hat this transfer pathway may only be important for highly contaminate d soils. The aim of reducing the daily intake of PCDD/F by contaminate d food is best reached by an effective emissions control. Volatilizati on of persistent lipophilic chemicals from the soil is a long-term pro cess and can lead to a secondary pollution of the atmosphere.