August 6, 2002

Mr. David Hunter
Editor
Chemical Week
888 7th Avenue
New York, NY 10106

Dear Mr. Hunter:

Your story with the sensational title "U.K. Study is First to Directly Link Chemicals to Low Sperm Counts" (July 24) misguides your readership about the nature and significance of the research being reported.

There is no reliable evidence that human sperm counts are declining as suggested by the title and, more significantly, the reported research has nothing to do with sperm counts. The study evaluated an isolated aspect of mice sperm function in an in vitro assay, which is quite different than sperm count. Also, since the natural estrogen did not result in all the observed changes, the differences are unlikely related to any weak estrogen-like activity of the natural or synthetic chemicals.

As far as nonylphenol is concerned, human exposure is very limited and its rapid metabolism and excretion means that sperm should not come in contact with NP. Moreover, the weight of scientific evidence clearly shows that nonylphenol has no effect on fertility or reproductive function.

This was most recently demonstrated in a three-generation reproduction and developmental study conducted by the National Institute of Environmental Health Sciences (NIEHS) (R.E. Chapin et al., 1999, Toxicological Sciences, vol. 52, pp. 80-91). The NIEHS study found no effects of nonylphenol on fertility or reproductive function even at the highest concentration tested. This conclusion was supported by a two-generation study conducted in Japan (T. Nagao et al., Reprod. Toxicol., vol. 15, pp. 293-315). Both of these studies involved extensive evaluation of male fertility, sperm count, sperm motility and detailed microscopic examination of the male reproductive organs and sperm and showed no evidence of any problems with sperm function.

These more definitive findings not only contradict the suggestions in your story with respect to nonylphenol, but also raise questions about the significance of the other claims made for this study.

The science demonstrating the safety of nonylphenol and its ethoxylates is extensive and summaries are available on the Alkylphenols & Ethoxylates Research Council web site (www.aperc.org). We are also pleased to respond to any queries with respect to "new studies" on health or environmental effects. We would further caution that any future reports of "new studies" with alleged profound significance, such as finding a link between chemical exposure and low sperm counts, be weighed against the large existing body of knowledge.

Sincerely,

 

Robert J. Fensterheim
Executive Director

 

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