May 2, 2001

Editor, ES&T
Miller Hall - Campus Box 1105
University of North Carolina
Chapel Hill, NC 27599-1105
Phone: (919) 966-0581
Fax: (919) 966-0582
E-mail: est@unc.edu

Re: Comment on "Estrogenicity Determination in Sewage Treatment Plants and Surface Waters from the Catalonian Area (NE Spain)"
Revised based on Editor's request of April 18, 2001

Dear Sir:

A recent paper in ES&T reported high levels of nonylphenol (NP), nonylphenol ethoxylates (NPEs) and nonylphenol ether carboxylate (NPEC) in sewage treatment plant (STP) effluents and receiving waters of the Llobregat River in Spain (1).

NP, NPEC and NPEs are highly biodegradable materials that are effectively removed in well-functioning biological STPs (2). Where effective sewage treatment exists, levels of these materials in receiving water are low, even in streams receiving a considerable input of industrial wastewater (3).

Studies of overloaded, and hence poorly functioning, biological treatment plants in Switzerland have demonstrated lower removals (4). Comparison of treatment plant operating performance, as measured by organic carbon removal, and NPE treatability showed a direct correlation. Consequently, finding high levels of NP, NPEC and/or NPEs in STP effluents and receiving waters, as reported (1), is an indication of overloaded and/or poorly functioning STPs.

Inadequate sewage treatment has important public health as well as environmental implications due to the release into the environment of human pathogens and innumerable potentially hazardous substances. Considering this, the paper's focus on NP, NPEC and NPEs seems rather narrow and largely irrelevant to the evident and previously documented (5) problems in the Llobregat River and its tributaries. It is important to recognize that as treatment removes sewage from water it also removes the NPE.

Improved sewage treatment in the Llobregat watershed would provide multiple benefits of a healthier fish population, cleaner drinking water, greater recreational opportunities and reduced threats to human health.

Sincerely,

Robert J. Fensterheim
Executive Director

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Literature Cited

1. Solé, M., López de Alda, M. J., Castillo, M., Porte, C., Ladegaard-Pedersen, K. and Barceló, D. Environ. Sci. Technol. 2000, 34, 5076-5083.

2. (a) Naylor, C. G. Textile Chem. Colorists 1995, 27, 29-33. (b) Naylor, C. G. Industrial Wastewater 1996, Sept/Oct, 61-65. (c) Bennie, D. T. Water Quality J. of Canada 1999, 34 (1), 103. (d) Mackay, L. G., Croft, M. Y., D. S. Selby and R. J. Wells J. of AOAC Int. 1997, 80 (2), 401-407.

3. (a) Naylor, C. G., Mieure, J. P., Adams, W. J., Castaldi, F. J., Ogle, L. D. and Romano, R. R. J. Am. Oil chemists Soc. 1992, 69, 695-703. (b) Naylor, C. G., Williams, J. B., Varineau, P., and Webb, D. Proceedings: CESIO 4th World Surfactants Congress, vol. 4, 378-391, 1996. (c) Field, J. and Reed, R. Environ. Sci. Technol. 1996, 30, 3544-3550.

4. Ahel. M., Giger, W. and Koch, M. Water Res. 1994, 28, 1131-1142.

5. (a) Ventura, F., Fraisse, D., Caixach, J. and Rivera, J. Anal. Chem, 1991, 63 (19), 2095-2099. (b) Guardiola, A., Ventura, F., Matia, L., Caixach, J. and Rivera, J. J. Chrom. 1991, 562, 481-492.

 

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