Thursday, July 18, 2019
It’s generally accepted in the scientific community that the best way to measure human exposure to bisphenol A, otherwise known as BPA, is through an analytical method called biomonitoring. In particular, measuring the amount of BPA in urine is a widely accepted scientific practice for measuring exposure because BPA is rapidly and completely eliminated from the body in urine. What enters the body (i.e., intake) is readily measured by what comes out in urine.
Because urine biomonitoring is relatively easy to do, researchers have conducted urine-biomonitoring studies on BPA in more than 30 countries around the world. It’s not just for their own idle curiosity; rather exposure is a critical parameter used by essentially all these health authorities worldwide to support their conclusion that BPA is safe as used. With the recent publication of two biomonitoring studies, Slovenia has joined this illustrious group of 30+ countries.
In the first study, a group of Slovenian and Greek researchers reported urinary levels of BPA in a diverse group of Slovenian children and their mothers and fathers. As concluded by the researchers: “The levels were comparable with the levels reported for other European countries and were all below the current health-based guidance values.” In other words, BPA exposure levels measured in the Slovenian group are safe based on a screening level assessment.
But the researchers didn’t stop there.
In a follow-up study, the researchers further explored BPA safety with three rigorous and complementary approaches:
• In the first approach, the researchers calculated intake of BPA from the measured levels of BPA eliminated in urine. These intake values were then compared to the safe intake level recently established by the European Food Safety Authority.
• The second approach started with the safe intake level and estimated the corresponding level of BPA that would appear in urine. This is a safe threshold known in the trade as a biomonitoring equivalent. The actual measured levels of BPA in urine were then compared with the biomonitoring equivalent.
• The third approach was the most complex, but also may be the most scientifically important because it focused directly on the amount of BPA actually in the bloodstream before it is eliminated in urine. This approach also allows a more nuanced assessment that takes into account physiological differences between children, women and men.
The researchers reported an impressive margin of safety of 100 or more between actual exposures to BPA in the Slovenian group and the safety thresholds in each of the three approaches. Reassuringly, the results from the three rigorous approaches were similar and clearly confirm that BPA intake in Slovenia is safe.
These new results from Slovenia are also generally consistent with the previous studies from more than 30 countries and confirm again that wherever you go in the world, you need not be concerned about exposure to BPA.