New analytical expressions are presented for cumulative losses of the Jury et al. <1983> behavior assessment type of model for volatile organic chemicals buried in soil vadose zones. These expressions are for the soil-surface cumulative volatilization flux and subsurface cumulative degradation and mass loss. At the soil surface a flux boundary condition is used which includes a nonzero, atmospheric volatile concentration. Numerical results for time-dependent surface flux and cumulative quantities are presented for this boundary condition. ¿ 2000 American Geophysical Union