The proximity of PAHs distribution to the equilibrium states among air, soil, water, and bottom sediment was assessed for future risk management and coherence test among environmental quality objectives (EQOs) in these media. Concurrently measured concentration data in the four media were used. In the study areas (Seoul, Shihwa/Banwol, and Taegu), nonequilibrium states prevailed among air, soil, and water except for some light PAHs between air and water. Elevated concentration in soil particularly caused significant deviation from equilibrium between soil and other media. Coherence criteria among these media should be determined based on steady state (not equilibrium) conditions. Sediment was in or near equilibrium with soil for all PAHs, indicating that sediment quality is closely related to soil quality and that the coherence between the EQOs of the two media is required in the study areas. As the concentration ratio of individual PAHs for a given medium pair was found to vary up to 4 orders of magnitude across the study areas, a factor of 10 as a threshold criterion for incoherence is apparently too strict to apply to the national scale of Korea.

No abstract

The KOrea Insecticide Exposure Model (KOIEM) was developed to facilitate ecological risk-based management of Korean insecticides. KOIEM, applied as a multimedia fate model, evaluates water, soil, air, and vegetation compartments based on three water-body types (streams, ditches, and ponds). Deltamethrin, a pyrethroid insecticide, was used to evaluate and create the model parameters. After exposure of both the stream and the ditch to deltamethrin, the KOIEM-predicted concentrations and the observed levels were in agreement. The model was also evaluated using the accuracy factor (AF), which was 4.32 and 0.35 for the stream and ditch, respectively. Ecological risk assessment was also performed to evaluate the application of KOIEM for four popular South Korean insecticides (cypermethrin, deltamethrin, diazinon, and permethrin). Despite the insecticides having low PECs in water, their risk quotients were typically above 1.0. Thus, KOIEM modification would be required in further studies to account for spatial variation.

No abstract

No abstract