Development and evaluation of a multimedia environmental fate and food web model for phthalate esters in False Creek, British Columbia

There is limited information on the environmental fate of di-alkyl phthalate esters (DPEs). To better understand the fate of DPEs and their primary metabolites, mono-alkyl phthalates (MPEs), a steady-state multimedia environmental fate and food-web model was developed and tested. The model suggests that the lower log Kow DPEs mainly flow out of the system and by a smaller extent in the ionized form of MPEs, or further biodegrade into phthalic acid. The higher log Kow DPEs are mainly bound to sediment that is buried and flow out of the system. The model also predicted that in fish, lower log Kow DPEs are mainly eliminated through gills whereas the higher log Kow DPEs undergo fecal route. Biotransformation of DEHP and mixture of C8 isomers are also predicted. This model can be used in preliminary ecological risk assessment to predict exposure concentrations, internal body burdens, and remediation targets in aquatic ecosystems.