The EPA's massive endocrine disruptor testing program is based largely on the public health scare that followed the publication of a controversial book entitled Our Stolen Future. Authored by Theo Colborn, the book examined reproductive and developmental abnormalities in birds and reptiles who were exposed to high levels of pollution in contaminated regions, such as the Great Lakes, and concluded that synthetic compounds had interfered with the animals' endocrine system to cause the abnormalities. Colborn's theory was that similar damage might be happening to humans through low-level environmental exposure to synthetic chemicals. Shortly after Our Stolen Future began to raise concerns, John McLachlan, a researcher at Tulane University, published an alarming study that suggested that low levels of several synthetic chemicals could become extremely potent endocrine disruptors when combined in the human body. McLachlan's tests prompted a public statement from the EPA calling the results "astounding," and EPA Assistant Administrator Lynn Goldman declared that the study was "the best case for synergy between chemicals at low doses that I have ever seen."
Heightened concern that followed the publication of these two studies resulted in a congressional mandate to test chemicals for their ability to disrupt the human endocrine system. This far-reaching requirement was inserted into the Food Quality Protection Act (FQPA) before its passage in August 1996. The FQPA dealt primarily with the important issue of reassessing pesticide residue levels in food, but the small section that dealt with endocrine disruptors — once in the hands of EPA officials — quickly turned into the most massive animal-testing program of all time, with the potential to dwarf even the high production volume (HPV) chemical-testing program in the number of animals who will be killed.
But since the FQPA was enacted, numerous questions have arisen surrounding the theories proposed by Colborn and others. For example, shortly after Congress passed the FQPA, John McLachlan of Tulane retracted his study, stating that there had been "a fundamental flaw" in his experimental design and that neither he, nor several independent researchers, had been able to duplicate the original results. In a letter to the journal Science, McLachlan acknowledged the enormous weight that had been given to his flawed study by regulators, stating, "[P]eople in many walks of life have, on their own, put great weight on this report as the basis for much discussion, thought, and even public policy."
The material presented by Colborn in Our Stolen Future has been widely criticized — both because of the book’s unsupported claims and its one-sided treatment of existing evidence. Scientific American strongly criticized the book shortly after its release stating, "The book is not scientific. ... The authors present a very selective segment of the data that have been gathered about chemicals that might affect hormonal functions. They carefully avoid evidence and interpretations that are not in accord with their thinking."
Additionally, a review published in the journal Science deplored "the authors' lack of discrimination between anecdotal reports and meticulous scientific studies. One paragraph describes a carefully crafted study, the next indulges in wild speculation." The reviewers concluded, "This lack of selectivity diminishes the impact of the book because it raises serious questions about the scientific judgment of the authors."
An even more critical review of Colborn’s endocrine theory recently appeared in The New Republic. The strongly worded editorial, entitled, "Science Fiction: Unraveling the Phony Scare Over Endocrine Disruptors," stated, "It’s strange to think how quickly speculative, lightly researched claims can go straight to the top of the national policy agenda, while so many undeniably genuine problems languish."
While scientists now generally agree that certain adverse effects on wildlife are the result of exposure to endocrine disruptors in the environment, the EDSP does not focus on these wildlife concerns. The testing protocols the EPA wants to put in place now are aimed exclusively at extrapolating from animals in laboratory tests to human health effects. However, many scientists have called for human population studies to determine the nature, extent, and severity of the problem before proceeding with a sweeping regulatory testing program. Further, the EDSP does not include any mechanism for actually reducing emissions and wildlife exposure to chemicals that are already known to be hazardous.
The definitive scientific report on endocrine disruptors is a recently released study by the National Academy of Sciences (NAS). In 1995, Congress commissioned the National Research Council, the investigative arm of the NAS, to critically review information on endocrine-related toxicants in the environment and examine the potential human health impact of the chemicals. In its exhaustive report (released after Congress had already mandated testing), the Council concluded that there is no solid evidence linking environmental endocrine disruptors to the most commonly cited adverse human health effects — including Colborn’s alarming theory that environmental endocrine disruptors were causing male reproductive disorders and some forms of cancer. The NAS report states that male reproductive disorders "cannot be linked" to environmental endocrine disruptors at this time and that an examination of all available information (including human health data) "does not support an association" between cancer and exposure to suspected endocrine disruptors.
Since the release of the NAS report, mainstream medical organizations have echoed the idea that there is no evidence of a human health threat from endocrine disruptors. For example, in its 1999 Handbook of Pediatric Environmental Health, the American Academy of Pediatrics states, "Environmental endocrine disruption in humans is mainly speculation." Two very recent independent scientific studies have cast further doubt on two frequently cited human health effects, finding that the incidence of hypospadias (misplacement of the urethra) is not increasing and that sperm counts are not declining.
Dr. Bernard Schwetz, acting deputy commissioner of the U.S. Food and Drug Administration, has written that "while there is general agreement that endocrine disruptors cause certain adverse effects in wildlife species, there is no such consensus about adverse effects in humans. Enormous amounts of human and laboratory resources were plowed into developing test batteries to detect hormonal activities of chemicals through the U.S. EPA, [yet] determining whether there were, in fact, adverse effects in humans from exposure to endocrine disruptors in the environment and, if so, characterizing the scope of the problem, seemed a much lower priority. ... It seems obvious that our focus should be on determining whether such a relationship exists and if so, characterizing the extent of the problem."
During a recent international conference on animal experimentation, many scientists denounced the EPA’s endocrine disruptor testing program as inherently wasteful and unrealistic, with one prominent toxicologist calling the EPA’s plan "blindly stupid." Others at the conference said that the EPA’s testing program represents "appalling toxicology" because the massive doses of chemicals that will be force-fed or injected into animals have no relevance to the low levels of chemicals to which humans might be exposed. Several scientists also raised concerns about the huge differences between the human and nonhuman animal endocrine systems and the questionable relevance of any data on potential endocrine disruptors obtained through animal testing. A U.S. government scientist attending the meeting agreed that the testing program is unscientific and ill-conceived but stated nevertheless that "due to commitments by laboratories and government agencies and the availability of funding, the program will proceed — justified or not."
Whereas European Union law requires that justification for causing pain to animals be established prior to their use in tests and that non-animal tests be used whenever practicably available, no similar regulations exist in the United States. The U.S. government is therefore able to push ahead with the endocrine disruptor screening program — a massive animal-testing plan that will cause immense animal suffering—in the face of serious questions about its justification and the validity and usefulness of the proposed tests. The EPA is unable even to define exactly what an "endocrine disruptor" is or what constitutes an "adverse effect" and has no idea how to interpret the massive amount of questionable data that will be generated.
The head of the European Centre for the Validation of Alternative Methods (a European Union-funded governmental entity) writes: "Very large numbers of animals [will be used] to test numerous chemicals with methods of questionable relevance to the human endocrine system and in the absence of clear evidence of human risk based on reliable and relevant information on mechanisms of toxic action or on likely levels of human exposure. We are therefore faced with the very real probability that a huge amount of unreliable hazard data will be generated, which will be impossible to interpret and use effectively for risk assessment, at an enormous cost in animal lives."
Because scientists are only beginning to understand the complex issues surrounding endocrine disruptors (as recently as November 1999, Theo Colborn was quoted in the press as saying, "We’re in the very early stages of understanding this"), many have expressed concern that regulatory testing in the near future will fail to accurately pinpoint chemicals that really are of concern. When members of the EPA’s endocrine advisory committee raised this question during a recent meeting, stating that the tests that the EPA plans to require include "only a very limited part of the potential universe of endocrine systems," Dr. Penelope Fenner-Crisp, an EPA senior scientist, could only respond that the decision to limit the number of effects covered by the tests was due to constraints that were "practical, albeit not necessarily scientific." When questioned as to why the EPA is not spending further time and effort on researching and developing a realistic strategy for endocrine disruptors, Dr. Fenner-Crisp referred to the time constraints set in the FQPA that require the EPA to "implement" the testing program by 1999, and she stated, "We have to do something that looks like implementation."
Concerns that the unrealistic timeframe set by the FQPA will result in a woefully inadequate program have also been raised by Dr. John Giesy, an environmental toxicologist and member of the National Academy of Sciences, who told scientists at a separate meeting, held shortly after the FQPA was enacted, "At this time, legislating endocrine testing is unbelievably stupid and a waste of resources that will lead to false positives in screening, but more importantly, to false negatives."
Others in the scientific community have expressed concern that by focusing solely on obtaining laboratory toxicity data, the agency will be left without the environmental exposure assessments and real-world data needed to prompt regulatory action for the tangible protection of human health and the environment. In other words, after millions of animals have been killed in laboratories, we will be no closer to actually reducing emissions of hazardous chemicals and protecting our environment.
The high level of uncertainty surrounding endocrine disruptors is surely what led the National Research Council to recommend repeatedly throughout its report that an intensive research program consisting of various epidemiological studies on the human population was critically needed. For example, the Council wrote, "Appropriately designed and conducted case-control and retrospective cohort studies are needed to document the presence or absence of associations between [endocrine disruptors] and various cancers in humans. ... Background concentrations of [endocrine disruptors] in humans, particularly in adipose tissue and blood, and other biota need to be established. In particular, routes of exposure and the effect of diet need to be assessed to provide a framework for examining the effects of these compounds in the general population and in highly exposed subpopulations. ... Prospective and cross-sectional studies using cohorts tracked from conception through adulthood are particularly needed on female and male reproductive endpoints."
The sensible alternative recommendations proposed by the NAS and others are being discounted by officials at the EPA. The EPA continues to press ahead with a sweeping regulatory program that relies almost exclusively on crude and cruel animal tests and ignores the major scientific issues that have arisen.
|
