To judge by the scary headlines and news reports, the latest
threat to American children comes in the shape of a plastic baby
bottle. According to the National Toxicology Program (NTP),
Bisphenol A (BPA), which is used in thousands of plastic consumer
products, including baby bottles, poses a danger to the health of
infants and children.
Supposedly, that is because BPA leaches out of plastic into the
blood stream where, even in low doses, it poses a risk to human
health. Canada last week declared BPA toxic and Canadian stores
rushed to remove anything containing it from their shelves.
Is BPA, in the minute doses consumed by children, really a risk
to health? Does the science clearly demonstrate that BPA can harm
babies, children or adults? Until the NTP released a preliminary
report on BPA last week, the answer was generally no.
There were some scientific studies that suggested even low doses
of BPA were dangerous, but the vast majority of studies failed to
find a significant and demonstrable risk. In fact, even the NTP
report was highly qualified, though you would never know it from
the press coverage. The NTP reported that the science raised
“some concern” about neural and behavioral effects in fetuses,
infants, and children based on “limited” evidence from low-dose
studies.
In its review of BPA, the NTP looked at 400 new studies. A mere
handful of the studies found a problem with the chemical. In
certain instances, a single study was cited to demonstrate harm.
More importantly, none of these studies involved human
populations, as all were performed with rodents. Even where they
have been studies of health problems in animals exposed to low
doses of BPA, there has been no evidence that these effects
persist later in life.
Studies and reports from a wide variety of regulatory and safety
agencies outside of the United States have given BPA a clean bill
of health. A comprehensive risk assessment by the European Union
found no convincing evidence that BPA affected development or was
carcinogenic. The Japanese Ministry of Environment, which
conducted extensive animal tests with BPA, concluded that there
was no clear evidence that low doses of BPA had
endocrine-disrupting consequences. In addition, German’s
Institute for Risk Assessment concluded that it did not
“recognize any health risk for babies that are fed from baby
bottles” containing BPA.
That is because the amount of BPA that babies or children absorb,
even under extreme exposure, is well below what toxicologists
call the Tolerable Daily Intake (TDI). Norwegian and Swiss
researchers found that the amount of BPA that could be extracted
from plastic bottles was 1 to 7 micrograms per liter of fluid,
compared with the EU’s TDI of 250 micrograms per liter of fluid.
In fact, the NTP report acknowledges that the exposure levels to
BPA that produced behavioral and developmental effects in animals
were significantly higher than the levels found in U.S. infants
and children.
The harms here are at least three-fold. First, an immensely
useful product has been labeled a health menace because of sloppy
science. Second, the public has been once again misled, in part
by single-issue activists, about the nature and ubiquity of risk.
The take-away lesson is that the world is chock full of unknown
and significant risks, particularly for children.
Third, and most disturbing for sensible, long-term risk
regulation, is that the NTP has capitulated to the precautionary
principle bandwagon. As the NTP said, “The possibility that human
development may be altered by Bisphenol A at current exposure
levels cannot be dismissed.”
However, that is equivalent to saying we cannot completely
discount the risk the sun will not come up tomorrow. Science
cannot prove negatives. We cannot expect science to provide us
with absolute assurance.
All we can demand is a reasonable protection from risk.
Fortunately, that is exactly what we have with BPA and baby
bottles.
