Environmental fate of endocrine-disrupting dimethyl phthalate esters (DMPE) under sulfate-reducing condition

Joseph K.H. Cheung*, Rita K.W. Lam, M. Y. Shi, J. D. Gu

*Corresponding author for this work

Research output: Contribution to journalArticlepeer-review

46 Scopus citations

Abstract

Dimethyl phthalate esters (DMPE) can easily be released into the environment from plastic products. As endocrine disruptors, DMPE mimic estrogenic activities in animals and humans. The metabolites of DMPE are suspected to cause even more serious health problems. Among the common sterilization techniques adopted in the study of DMPE degradation, the average loss of the parent DMPE compounds after autoclaving was as high as 21.26%. In contrast, the loss after 0.2 μm filtration was significantly lower at 2.28%. It is suggested that filtration should be used over autoclaving for sterilizing DMPE. The environmental fate of DMPE under sulfate-reducing condition was simulated and studied in microcosm system. It was observed that dimethyl phthalate (DMP), dimethyl isophthalate (DMI) and dimethyl terephthalate (DMT) could not be mineralized over an extended period of 6 months, but with the transformation to the respective monomethyl phthalate and/or phthalic acid. The dominant species of microorganisms utilizing individual DMPE isomer as the sole carbon source were isolated and identified as facultative anaerobe Thauera sp., Xanthobacter sp. and Agrobacterium sp. for DMP, DMI and DMT, respectively. This study illustrates that the detrimental DMPE and their natural metabolites may accumulate in the sulfate-reducing environment. Accordingly, proper surveillance program should be devised to monitor both the parent compounds and degradation intermediates of DMPE in order to protect the aquatic ecosystem and human health.

Original languageEnglish
Pages (from-to)126-133
Number of pages8
JournalScience of the Total Environment
Volume381
Issue number1-3
DOIs
StatePublished - 1 Aug 2007
Externally publishedYes

Keywords

  • Anaerobic degradation
  • Dimethyl phthalate ester
  • Endocrine disruptor
  • Plasticizer
  • Sterilization
  • Sulfate-reducing condition

Fingerprint Dive into the research topics of 'Environmental fate of endocrine-disrupting dimethyl phthalate esters (DMPE) under sulfate-reducing condition'. Together they form a unique fingerprint.

Cite this