It is possible for some chemicals to achieve an effect within a system other than that of the intended/desired result for which they were employed. One such side effect can be the perturbation of an organism’s endocrine system. Chemicals capable of this are collectively known as “endocrine disrupting chemicals” (EDCs). The presence of these EDCs in the environment has the potential to cause adverse effects in wildlife and humans. This investigation focuses on two EDCs, nonylphenol (NP) and nonylphenol polyethoxylates (NPEO<sub>x</sub>), and their occurrence in various environmental matrices. NPEO<sub>x</sub> is a surfactant used in a variety of applications including detergents and pesticides. NP is used in the production of certain types of plastic and is also found during the biodegradation of NPEO<sub>x</sub>. Methods for the extraction (e.g. liquid/liquid, solid phase, Soxhtherm and Accelerated Solvent Extraction (ASE)) and analysis (i.e. GC-MS and LC-MS) of these chemicals from waste water treatment works (WWTW) waters, industrial effluents, river waters, sludges and sediments were developed and applied. A study of six WWTW was conducted to investigate concentrations of NP (1.1-29.3 mg/l) and NPEO<sub>x</sub> (1.6-28.4 mg/l) in effluents within each works. It was found that several, but not all, WWTW effluents contained detectable concentrations. An investigation of the bottom sediments of two contrasting freshwater lochs, Tay and Leven, showed that neither NP nor NPEO<sub>x</sub> was detectable in bottom sediments from Loch Tay, whereas Loch Leven bottom sediments revealed detectable concentrations of NP (8-631 mg/kg) and NPEO<sub>x</sub> (87-925 mg/kg). Other matrices, including single-amended soils (239-586 mg/kg NP and 123-343 mg/kg NPEO<sub>x</sub>), WWTW sludges (86-3843 mg/kg NP and <0.45-<10.8 mg/kg NPEO<sub>x </sub>), and river waters (1.1-5.4 mg/l NP and 0.6-1.6 mg/l NPEO<sub>x</sub>, also had detectable concentrations in some of the samples. Improvement of NP and NPEO<sub>x</sub> removal processes by the water industry, during water purification, is needed as contamination by waste water effluents introduces NP into the fresh water environment at concentrations above the recommended safe level of 1.0 mg/l (Environmental Agency for England and Wales). No recommended limits have been set for NPEO<sub>x </sub> at this juncture.
| Identifer | oai:union.ndltd.org:bl.uk/oai:ethos.bl.uk:662126 |
| Date | January 2003 |
| Creators | Smith, Pamela |
| Publisher | University of Edinburgh |
| Source Sets | Ethos UK |
| Detected Language | English |
| Type | Electronic Thesis or Dissertation |
| Source | http://hdl.handle.net/1842/12987 |
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