title: Biodegradation of mono-alkyl phthalate esters in natural sediments.
abstract: Mono-alkyl phthalate esters (MPEs) are primary metabolites of di-alkyl phthalate esters (DPEs), a family of industrial chemicals widely used in the production of soft polyvinyl chloride and a large range of other products. To better understand the long term fate of DPEs in the environment, we measured the biodegradation kinetics of eight MPEs (-ethyl, -n-butyl, -benzyl, -i-hexyl, -2-ethyl-hexyl, -n-octyl, -i-nonyl, and -i-decyl monoesters) in marine and freshwater sediments collected from three locations in the Greater Vancouver area. After a lag period in which no apparent biodegradation occurred, all MPEs tested showed degradation rates in both marine and freshwater sediments at 22 degrees C with half-lives ranging between 16 and 39 h. Half-lives increased approximately 8-fold in incubations performed at 5 degrees C. Biodegradation rates did not differ between marine and freshwater sediments. Half-lives did not show a relationship with increasing alkyl chain length. We conclude that MPEs can be quickly degraded in natural sediments and that the similarity in MPE degradation kinetics among sediment types suggests a wide occurrence of nonspecific esterases in microorganisms from various locations, as has been reported previously.
authors.affiliation: School of Resource and Environmental Management, Faculty of Applied Sciences, Simon Fraser University, Burnaby, British Columbia, Canada V5A 1S6.
authors.forename: S Victoria
authors.initials: SV
authors.lastname: Otton
authors.forename: Srinivas
authors.initials: S
authors.lastname: Sura
authors.forename: Joel
authors.initials: J
authors.lastname: Blair
authors.forename: Michael G
authors.initials: MG
authors.lastname: Ikonomou
authors.forename: Frank A P C
authors.initials: FA
authors.lastname: Gobas
mesh_terms: D001673:Biodegradation, Environmental; D002170:Canada; D004952:Esters; D019015:Geologic Sediments / Q000737:chemistry* / Q000382:microbiology; D007700:Kinetics; D010795:Phthalic Acids / Q000737:chemistry* / Q000378:metabolism; D014871:Water Microbiology
chemical_list: D004952:Esters; D010795:Phthalic Acids; C032279:phthalic acid