Is Anyone Safe From BPA?
BY STEVE HENTGES | JULY 19TH 2017 05:36 PM

Everyone has heard about bisphenol A (BPA). It’s primarily used as a raw material
to make polycarbonate plastic and epoxy resins, both of which are highperformance materials used in many consumer products that help to make our lives
better and safer. But that’s probably not what you’ve heard.
What you may have heard is that we’re all exposed to BPA. And it’s true, we
probably are all exposed to BPA. But unless you’re an exposure scientist whostudies exposure to chemicals for a living, just knowing we’re exposed to BPA isn’tvery useful without knowing a lot more.
In particular we need to know how much BPA we’re exposed to and whether thoselevels are safe or not. That concept is critical to understanding the safety of mostanything we’re exposed to, whether intentionally or not. For example, taking one
aspirin may safely eliminate your headache, but taking a whole bottle of aspirin
may eliminate your life. The difference is important.
So just how much BPA are we exposed to and are those levels safe? This is wherean important new study published in the journal Environmental Pollution provides
some very useful information. What the researchers realized is that an enormous
amount of data on consumer exposure to BPA is already available. It just wasn’t
all in the same place where it could be most useful, until now.
It’s well known that people quickly eliminate BPA from the body through urine
within hours of exposure. Measuring BPA in urine is considered the best way toevaluate exposure to BPA since what goes in (i.e., exposure) comes out in urine
where it’s easy to measure.
What the researchers did was search the scientific literature for studies thatmeasured levels of BPA in urine. They found more than just a few studies: “[i]ntotal, we obtained over 140 peer-reviewed publications, which contained over
85,000 data [points] for urinary BPA concentrations derived from 30 countries.”
The researchers then sorted the data by age group (adult men and non-pregnant
women, pregnant women, and children) and country to assess whether exposure

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levels are safe or unsafe for these groups. That assessment was done bycomparison of the exposure levels with safe intake limits set by government bodies
worldwide.
Compared to what you may have heard, the results may surprise you: “[i]t isevident that the national and global estimated human BPA daily intakes in thisstudy are two to three orders of magnitude lower than that of the TDI [Tolerable
Daily Intake] … recommended by several countries.” In other words, actual
exposure to BPA is hundreds to thousands times below the safe intake limit.
These results provide very strong support for the views of government bodies
worldwide on the safety of BPA. For example, the U.S. Food and Drug
Administration (FDA) answers the question “Is BPA safe?” with the unequivocal
answer “Yes.”
What Did the Researchers Do and What Did They Find?
As noted by the researchers, “[t]o evaluate BPA’s potential risk to health, it isimportant to know human daily intake.” In general there are two ways to measure
daily intake of a substance.
One way is to measure how much of the substance goes into the body. A second
way is to measure how much of the substance comes out of the body as it iseliminated. The preferred approach for BPA, by far, is to measure how much BPA
is eliminated from the body in urine, a technique known as urine biomonitoring.
The reason is that BPA is efficiently converted in the body to a biologically inactive
metabolite after exposure, which is then quickly eliminated from the body inurine. Essentially the metabolite concentrates in urine, which makes it easy tomeasure with sensitive analytical instruments. As noted by a prominent group of
researchers in regard to BPA and similar substances, “urine is the most dependable
biomonitoring matrix for population research.”
This has not gone unnoticed by researchers who have generated urine
biomonitoring data on BPA for more than 10 years. What the authors of this new
study realized is that quite a bit of data has been generated over this time period,
but it is difficult to comprehensively understand since the data is embedded in awide variety of separate studies that were conducted for different purposes.

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To resolve this dilemma, the authors searched the peer-reviewed scientific
literature for urine biomonitoring data on BPA regardless of why the data wasgenerated in the first place. By mining the literature in this way, the authors
uncovered an astounding amount of data that, taken together, provides a deep
understanding of human daily intake of BPA.
Overall, the authors found over 140 independent studies that reported urine
biomonitoring data for BPA. Together the studies include more than 85,000 data
points from individuals in 30 countries. The studies include a significant amount ofdata for pregnant women and children, which is important since these two groups
are generally considered as subpopulations that might be more sensitive to effects
from chemical exposures.
What Does The Data Mean?
The raw data that was analyzed simply measures the concentration of BPA, in theform of its metabolite, in urine. Without additional information, the raw data isdifficult to understand or interpret with respect to safety.
To interpret the data, the researchers estimated daily intakes of BPA forcomparison with safe intake limits established by government bodies
worldwide. Intakes are fairly easy to estimate since studies on human volunteers
show that BPA is entirely eliminated in urine after exposure. Essentially, what goesin (i.e., intake of BPA) is equal to what comes out (i.e., amount of the BPA
metabolite in urine).
The results were presented in an easy to understand graphical format as bar chartsthat show estimated daily intakes of BPA by country for each of the three agegroups. For example, estimated intakes for adults are shown in the bar chart
below.

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On a global basis, the estimated daily intake of BPA for adults is approximately 31nanograms BPA/kilogram bodyweight. Estimated intakes on a country basis show
only slight variation. With one exception on the low end, intakes for all othercountries range from approximately 20-60 nanograms/kilogram bodyweight witheach country differing from the global value by a factor of two or less.
This very low intake of BPA is consistent with how BPA is used and the low potential
for people to contact BPA. Most BPA is chemically consumed as a raw material to
make polycarbonate plastic and epoxy resins. Although we contact these materialsin consumer products every day, the amount of residual BPA in these materials isvery low, typically less than 50 parts per million.
The estimated daily intake for pregnant women is slightly higher at approximately
42 nanograms BPA/kilogram bodyweight and the estimated daily intake for children
is approximately 60 nanograms BPA/kilogram bodyweight. Since other studies
have shown that most BPA exposure comes from the diet, the relatively higher foodintake for children may account for the higher BPA intake.
The authors also assessed whether their global daily intake estimates could beconsidered to be representative of the global population. Based on other recent
research and their own analysis, the authors concluded that urine samples from aminimum of 1,000 people are required for an accurate estimate of daily intake for apopulation.

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Considering the large amount of data available and analyzed in this study, theauthors noted that “the estimated global BPA daily intakes in this study for adults,
pregnant women and children were representative as the urine sample sizes wereover 16,000 [for each group]. To the best of our knowledge, this is the first timethat reasonable worldwide human BPA daily intakes have been established for these
population groups.”
Most importantly, the authors concluded by comparing the estimated daily intakesof BPA for each age group with the TDI (i.e., safe intake limit; 50 micrograms
BPA/kilogram bodyweight) for BPA that has been established in several
countries. In each case, as noted by the authors, it is apparent that estimateddaily intakes are two to three orders of magnitude below the TDI. The TDI wasestablished to be protective of all age groups, including pregnant women andchildren, so that conclusion is applicable to all age groups.
Since estimated daily intakes varied only slightly by country, that conclusion is also
applicable to all countries. To go back to where we started, is anyone safe fromBPA? Based on a large amount of data the simple answer is yes, we’re all safe
from BPA.

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