A Focus article, "Extra Ingredients: Hormones in Food," in the August issue of EHP (102:632-635), included a brief but well-researched and generally accurate account of the debate over recombinant bovine growth hormone (rbGH). But, in quoting Consumers Union's Jean Halloran, your report unduly emphasized one narrow technical issue and left an erroneous impression of why the CU opposes the use of rbGH.

Halloran did indeed note that the hormone insulinlike growth factor 1 (IGF-1), which is found at elevated levels in milk from cows treated with rbGH, has been shown to promote the growth of tumor cells in laboratory experiments. However, she made that point in the context of explaining some of the unanswered questions about possible long-term public health impacts of rbGH use. Exposure to IGF-1 is one of several issues on which the CU believes more and better scientific data are needed. But by emphasizing this point, your report implied that CU currently believes the use of rbGH increases consumers' cancer risk. That is not the case.

CU has spoken out against the use of rbGH for several years, and we will continue to do so. Our posture is based on a broad analysis of the benefits, costs, and risks to consumers of the use of this hormone, not primarily on the narrower and largely theoretical possiblility of increased cancer risk. Whatever its perceived benefits to the drug companies who sell it and the dairy farmers who choose to use it, rbGH offers no clear benefits to consumers. The drug's purpose is to boost milk production, but the U.S. already suffers from a surplus of milk. Economic analyses indicate that the retail prices of milk and milk products do not go down in response to an increased oversupply. But the federal government is committed to buy surplus milk, and the cost to taxpayers of that dairy-industry support program could increase by hundreds of millions of dollars in the next few years because of rbGH use. In addition, CU, like the FDA, believes that use of rbGH will increase the risk of udder infections in treated cows, which in turn is likely to result in increased antibiotic use, and may produce a slight decline in the average quality of milk from rbGH-treated herds.

Given these likely impacts of rbGH use, and the lack of any tangible benefit to consumers to offset concern about unresolved questions of long-term health impacts, we are not surprised that surveys show a large majority of the public would prefer not to buy milk from rbGH-treated cows. CU believes consumers have the right to make that choice, and the fate of rbGH should be decided by market forces. For those reasons, we will continue to press for appropriate labeling of milk and dairy products from rbGH-treated cows.

Rhoda H. Karpatkin
Edward Groth III
Consumers Union
Yonkers, New York

Controlling Malaria

Since I started receiving EHP, I have again "reawakened" my insatiable appetite for biological investigations. The Focus article, "Global Climate Change: Beyond Sunburn," in the May 1994 issue (102:440- 443) was particularly interesting because for a long time now, I have argued the case of strategic seasonal control of malaria rather than the current approach of treating or curing the disease with different antimalarial drugs. The biggest problem we have in this part of the world is that chloroquine does not seem to be that effective any longer. Approaches based on seasonal climatic changes may offer a higher chance of success in controlling malaria than the current approach.

J. S. Phiri
Pesticides and Toxics Division
Environmental Council of Zambia
Lusaka, Zambia

A Matter of Nomenclature

I am writing to request your assistance in ensuring that all future articles relating to "glycol ethers" published in EHP use specific terminology to refer to the specific compounds(s) rather than a general category description.

The terms "glycol ethers" and "ethylene glycol ethers" are commonly, and incorrectly, used to report data which are only applicable to specific members of the general chemical category. The term "glycol ethers" refers to a very broad group of chemicals, which despite their structural similarities, have demonstrated distinctly different toxicity profiles.

Over the past decade, many publications focused on the lowest molecular weight ethylene glycol ethers, ethylene glycol ethyl ether (EGEE) and ethylene glycol methyl ether (EGME). Studies in the early 1980s showed these compounds caused adverse reproductive and developmental effects in laboratory animals. As a result, manufacturers for many years have recommended against their use in any consumer products and have kept occupational exposure very low.

Higher molecular weight ethylene glycol monoethers that have been tested have not been associated with significant adverse developmental and reproductive effects. In fact, the results of research on these compounds contrast with the data on EGEE and EGME. This is true in particular for the largest volume product in the class, ethylene glycol butyl ether (EGBE). EGBE has been shown not to be a primary developmental, nor a reproductive, toxicant.

It is inappropriate to refer to the toxicity of "glycol ethers." Each of the individual compounds has demonstrated its own toxicity profile, with EGBE and other higher molecular weight glycol ethers being of relatively low toxicity. Authors should be careful when discussing any of these compounds to identify them specifically. This is particularly true in titles and abstracts since the use of the generic term can imply that the effects reported apply to all members of the chemical class. We seek your assistance in educating authors in these distinctions and recommend they identify the specific subjects of their research in the titles of their papers.

I would be glad to offer any additional information to your journal or individual authors to assist in improving the terminology used for these compounds. Inquiries should be addressed to Chemical Manufacturers Association, 2501 M Street, NW, Washington, DC 20037; phone: (202) 887-1293.

Kathryn A. Rosica
Chemical Manufacturers Association
Washington, DC

Source for MCS Facts

The Human Ecology Action League, Inc. (HEAL) was founded in 1977 as an information and education organization concerned with the health effects of environmental exposures. One such health effect is the phenomenon now generally known as multiple chemical sensitivity (MCS). MCS has been an important focus of HEAL's information and education activities since its inception.

Readers of Environmental Health Perspectives may be interested in various HEAL publications, including "Selected Bibliography: Chemicals and Health" (1993) and "Selected Bibliography: Pesticides and Human Health 1983- 1993" (1994). "Chemicals and Health" should be of particular interest to those who want to review research on low-level chemical exposures and human health, with emphasis on MCS and other sensitivity disorders. We believe this bibliography to be the most comprehensive in print to date on this topic.

"Pesticides and Human Health" provides a decade-long snapshot of health-related pesticide research. Recent federal interest in reducing pesticide use and exposures makes this bibliography a timely document.

Your readers may contact our office for more information regarding these and other HEAL publications: Human Ecology Action League, PO Box 49126, Atlanta, GA 30359.

Thank you for your interest in MCS. We hope you will publish more articles on it in the future.

Muriel A. Dando
Human Ecology Action League
Atlanta, Georgia

Last Update: June 4, 1998