As a toxicologist with nearly two decades of experience in human health risk assessment, I believe that there is no scientific reason to make a link between chemicals found in recycled rubber mulch in playgrounds and any health issues (“Aromas/San Juan School Board seeks more information on potential rubber mulch replacement,” 10/31/16).
The scientific community has looked at this issue many, many, times. There is a substantial body of research — more than 90 peer-reviewed studies, reports, and evaluations from academics, state health departments, and third parties — that does not find any link between this material and adverse health effects. The few contrary studies that have been cited in some media stories generally do not take into account actual exposure to these chemicals, and simply rely on the presence of these chemicals as a reason for alarm.
Many common products we interact with as part of everyday life contain low levels of chemicals that do not pose a threat, but could if they existed at significantly higher levels. Presence alone does not necessarily equal danger. For example, chemicals such as arsenic and polycyclic aromatic hydrocarbons may be present in recycled rubber, but at trace levels similar to those found in natural soil.
Children’s safety should be placed above all else, but when making decisions about installing playground surfaces, unsubstantiated fears shouldn’t undermine science.
—Michael Peterson is a board-certified toxicologist at Gradient, an environmental and risk sciences consulting firm. He serves as scientific adviser to the Recycled Rubber Council.