Rethinking toxic chemical risk
There's an interesting debate emerging in the public health world. It has to do with whether we need to rejigger our thinking about the risks pesticides and other chemicals pose to children's health.
Traditionally, we've had a "disease-oriented" approach, assessing risk based on the severity of a health outcome (think birth defects or cancer). But earlier this month a provocative Environmental Health Perspectives article argued that a "population approach" might be wiser — meaning that even when a health effect is not severe, if it's affecting a huge number of our children (think dropping IQs), we should be paying close attention.
Our colleagues at the Environmental Defense Fund described the issue well in a recent blog, highlighting the EHP article's findings that population-wide impacts of chemical exposures are “surprisingly” large "due not so much to their effect sizes, but rather to the prevalence at which children in the U.S. experience these exposures."
If we really are talking about protecting public health, focusing on such widespread impacts — and taking action to prevent them — would seem to emerge as priority. Clearly, serious disease impacts represent a tremendous burden as well and cannot be brushed aside. It may sound overly dramatic, but we really do ignore the less severe, widespread impacts of chemical exposure at our peril.
The EHP article's author, Dr. David Bellinger of Boston Children's Hospital, puts it this way:
Although a factor associated with a large impact would be a significant burden to a patient, it might not be a major contributor to the population if it occurs rarely. Conversely, a factor associated with a modest but frequently occurring impact could contribute significantly to population burden.
The argument that public health priorities around chemical risks must focus on the “breadth” of an impact just as much as its “depth” makes very good sense.
This post appeared previously at GroundTruth.org.