Susan Schantz, a professor of comparative biosciences in the College of Veterinary Medicine and member of Beckman’s Cellular and Molecular Foundations of Intelligent Behavior Group, answers questions about environmental toxins, where to look for them, and who is most at risk from exposure.
What environmental contaminants are you studying and where are they most commonly found?
We are studying chemicals that are found in consumer products we use on a daily basis, including phthalates, which are used as solvents and scent stabilizers in many personal care and household products, in some plastics including medical supplies like IV bags and tubing, and in some food packaging and building materials. We are also studying phenols including bisphenol A (BPA) and its replacements BPF and BPS, which are used in some types of plastics and food packaging, including the epoxy resin used to line many metal food and drink cans; benzophenone-3, which is used in sunscreens; triclosan, which is used in some antibacterial soaps and toothpastes; and parabens, which are used as antimicrobials in many personal care products and in makeup.
Why are these chemicals so prevalent in household products?
The chemicals have useful properties that can add flexibility to plastics, stabilize the scent in lotions and other personal care products, or screen out the sun’s harmful UV rays. Unfortunately, very few chemicals are completely without risk, and many of the chemicals that are used in consumer products have not been adequately tested for safety.
Who is most at-risk from exposure to these chemicals? What impact do they have?
Pregnant women, developing fetuses, young children, and the elderly are considered to be most at risk from chemical exposure. The impacts can vary widely depending on the chemical, the timing of exposure, and the amount of exposure. The chemicals we study are all endocrine disruptors, and, as such, can disrupt the action of hormones in the body. Hormones are critical to maintain a healthy pregnancy and to ensure normal development, so we focus on pregnant women and their offspring in our research.
Why is replacing one potentially harmful chemical in a product not necessarily the solution?
(For example, you have said BPA can simply be replaced with another, less-studied chemical that might have the same affect.)
Too often what happens is what we refer to as "regrettable substitution": a chemical that appears to have health risks is replaced with another chemical that has not been adequately tested for safety and turns out to have health risks of its own.
Why is it difficult to regulate the use of chemicals in products?
This is a hard one for me to answer. The regulatory system in the U.S. is complex, distributed across multiple federal agencies (e.g. the Food and Drug Administration, Environmental Protection Agency, and the U.S. Department of Agriculture) and there are inadequate resources to fully evaluate the safety of even a fraction the tens of thousands of chemicals that are already on the market.
Is buying “natural” products always better?
Not necessarily. I don't think how the word "natural" is used is regulated, so you can't always be sure what you are getting.
What one thing should consumers do to reduce their exposure to environmental contaminants?
I would suggest a few things: First, eat fresh rather than canned or processed foods whenever you can. Buy organic produce if you can afford to and have access. Our Project TENDR website has links to information about which types of fruits and vegetables tend to be most contaminated with pesticides. Wash all produce thoroughly with plenty of water (but do not use any soap). Use fragrance-free personal care and household products—these are less likely to contain phthalates. Fragrance-free is not the same as unscented; many unscented products do contain fragrance. Do not use antibacterial soaps. There is no scientific evidence that they work any better than plain soap and water. Avoid toothpaste that contains triclosan. Use glass or stainless steel containers to store food and beverages.