THE DOSE MAKES THE POISON?

I have long believed that this centuries-old and widely used premise is false. “The dose makes the poison” is based on the belief that chemicals are toxic, less toxic, or non-toxic depending on how much of it a biological organism is exposed to. In other words: It's the size of the dose that makes it poison: the higher the dose, the greater the effect. This premise is used to make public health standards regarding exposure levels of chemicals in food, water, and air.

BUT WHAT IF the basis for determining safe concentrations of chemicals in our food, water, and air is flawed? “The idea that 'the dose makes the poison' relies on the assumption that the higher the dose of any particular chemical, the greater its toxic effect on living organisms. However, this assumption is not always correct. The more we learn about the complex ways in which organisms interact with the chemicals to which they are exposed, the more difficult it seems to be to establish understandings that can be generalized across different types of organisms and chemical substances.”

We are learning that “low-dose exposures can have impacts as significant as higher exposures, ...that mixtures among the many chemicals within us can have synergistic negative impacts” , and that “sensitivity to contamination is not the same at all stages of the life of an individual.”

“[Animal and cell research results] demonstrate that low doses can have qualitatively different effects than high doses, and that the low dose effects cannot be predicted on the basis of high dose results. Contaminants that mimic hormones are of concern for this reason. ...[These contaminants] can disrupt crucial life functions at doses much lower than those previously thought to be safe, especially in fetuses and children. Perhaps for compounds such as these the slogan should be 'No dose is low enough.' ” (Which is how some scientists view carcinogens.) And yet public health standards (including occupational exposure limits) historically have not taken this into account, and many exposure limits have not been re-calculated using this new information.

What a great argument this makes for my continued insistence on the importance of preventing chemical exposures and eliminating toxic chemicals whenever possible! Gosh, am I a broken record or what?! [For the CD-only generation, ask someone older than you to explain the broken record concept!.] If I repeat myself—and I do!—it is because this issue is so important to your health that if I could, I would call you every morning just to remind you. [But then you'd want a reminder call for your grocery list, your social engagements...It would get out of hand right away.] So you're on your own here, except for whatever help you can get from those around you. Wouldn't it be nice if we all helped each other make it through our day?

For more information on this topic, click this link.

1. The Dose Makes the Poison–Or Does It? By Nancy Trautmann Ph.D., directs Cornell University’s Environmental Inquiry program
2. Philip R. Lee, MD, and Steve Heilig, MPH; in Environmental Health
3. Welshons, WV, KA Thayer, BM Judy, JA Taylor, EM Curran and FS vom Saal. 2003. Large effects from small exposures. I. Mechanisms for endocrine disrupting chemicals with estrogenic activity.
4. John Peterson Myers, PhD, Dianne Dumanoski and Theo Colborn, PhD; Our Stolen Future, A Decade Later