August 7th, 2008 at 8:31 am
Interview with Geoffrey C. Kabat, author of Hyping Health Risks
The following is an interview with Geoffrey C. Kabat, who is senior epidemiologist at the Albert Einstein College of Medicine in New York City and author of Hyping Health Risks: Environmental Hazards in Daily Life and the Science of Epidemiology.
Question: How do these scares get started?
Geoffrey Kabat: Health scares of the kind I examine can arise in different ways. In some cases, the publication of a scientific report can provide the initial impetus. This happened in the case of electromagnetic fields and childhood cancer, which really was put on the map, so to speak, by the publication of a paper in the American Journal of Epidemiology in 1979. It was a study with a number of major weaknesses, and yet it seized the imagination of scientists. It was not substantiated by later studies. But it created concern and this led to lawsuits against electric power companies, further scientific studies, a great deal of media attention, and increased concern.
In other cases, a scare can arise due to anecdotal reports of adverse health effects, in the absence of any scientific studies. This was the case with silicone breast implants. Once large, well-designed studies were carried out, they did not support the claims of adverse effects.
Q: Who is responsible for what you call the “manufacture” of certain health hazards?
GK: A variety of different actors can, for different reasons, contribute to manufacture of a health risk, or to its inflating. Of course, this includes the media, but also scientists eager to promote their results; health and regulatory agencies, which will take up an issue once there is a certain level of scientific and public concern; and advocates with a stake in a specific health issue. In addition, lawyers and politicians may play a role. Depending on the health hazard in question, these actors may play more or less central roles. But what tends to happen is that certain aspects of the evidence tend to get emphasized while others, which may be equally important, tend to get ignored.
Q: What are the consequences of inflating health hazards? Why should we care?
GK: Inflating a health hazard or manufacturing one where none exists can have very tangible and harmful consequences. First, it creates needless anxiety. This happened in the case of parents being worried about how power lines adjacent to their children’s school might affect their children’s health, to give one example. Secondly, it creates confusion about what well-established and substantial health risks people should pay attention to. Third, well-intentioned policies can be promoted by agencies which feel the need to respond to an alleged hazard. In some cases, these policies have had more harmful effects than the hazard they were intended to address. One example of this is that the narrow focus on fat in the diet as a risk led to ill-conceived policies which in turn led to increased consumption of calories from carbohydrates, and this is believed to have contributed to the increase in obesity in recent years.
Q: In parts of your book you seem to be saying that we should not worry about environmental pollution – is that the message you mean to convey?
GK: Quite the contrary. Degradation of the environment, whether it is local or on a continental or global scale, is enormously important and requires our increasing attention. It represents an enormous challenge both to monitor its extent and health effects and to design rational policies to address it. We stand a better chance of doing this if we don’t get carried away by things that are not real problems.
My point is merely that we need to make distinctions between exposures that are so low that they are unlikely to have any effect and those that are of much greater magnitude and where intervening is likely to have a tangible effect. Again, one has to have a sense of perspective, of proportion.
Q: Epidemiology has recently been criticized by the science writer Gary Taubes for getting things wrong and for possibly doing more harm than good to the public’s health. What is your response to this criticism?
GK: I think that, starting with his influential article in Science magazine in 1995, Taubes performed a real service by drawing attention to the problem of the reporting of inconsistent results from epidemiologic studies and the confusion this creates in the public. More recently Taubes has pointed out that overstating the evidence on certain questions – like policies promoting a low-fat diet starting in the 1990s – may have done more harm than good.
Where I think Taubes goes off the rails is that he attributes these errors to the fact that epidemiology is mainly an observational science. I would argue that these errors are not due to the flawed nature of epidemiology but rather to people overstating the evidence due to agendas which have little to do with science. This is why I attempt to describe what I have referred to as “the sociology of health risks.”
Also, Taubes does not seem to have any appreciation for the fact that epidemiology has a long list of achievements, or that the results of epidemiologic studies need to be considered in conjunction with evidence from laboratory studies and from other disciplines. Big advances often involve a convergence of evidence from a variety of fields. Taubes’ inability to acknowledge the accomplishments of epidemiology and his apparent animus against the discipline is hard to understand.
Q: What motivated you to write this book?
GK: In the early 1990s I noticed that certain issues in epidemiology seemed to be distorted or exaggerated and that the public was being given the wrong idea. So, I tuned in to a number of these issues, some of which I was doing primary research on. I tried to assess what the evidence actually indicated and where certain agency reports or partisan interpretations seemed to be overstating the evidence.
You can also read the introduction to the book.
This is a Caravan book.