UK Teenagers and BPA Exposure - Something to Be Afraid Of?
Judging by the headlines in major UK newspapers during February, it must have been a slow news period. Using the scariest of terms, the stories reported that teenagers in the UK are exposed to Bisphenol-A (BPA). The "scare appeal" of the headlines is obvious. And what the stories reported is not exactly news, although it did fill space in the newspapers. So how does one small study garner so much media attention?
The simple answer is that researchers at the University of Exeter issued a press release about their new study. Without digging any deeper than the press release, journalists wrote their stories and the headline writers added their alarming spin to publicize it.
The so-called "citizen-science project" was designed, implemented and analyzed by a group of teenagers in the UK with guidance from the university researchers. Essentially the project measured exposure of 94 UK teenagers to BPA and aimed to determine whether certain specified dietary changes could reduce exposure.
Aside from the question whether press releases are an appropriate form of scientific discourse, the study, press release, and media stories are all woefully lacking in one important aspect: they lack any scientific context to understand what the study results mean.
The study is far from the first time that BPA exposure has been measured. Using the same scientific technique as in the UK study, researchers worldwide have measured exposure to BPA in many other populations. In fact, the scientific literature contains over 140 studies that include results from over 85,000 individuals.
In a paper published just last year, the results of these many studies were analyzed together to understand exposure to BPA on a global level and to interpret what the results mean. The researchers concluded:
"[i]t is evident that the national and global estimated human BPA daily intakes in this study 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 of times below the safe intake limit for all populations studied around the world.
As it turns out, the UK teenagers' BPA exposure was below average compared to the levels reported in these many studies worldwide. So quite contrary to the provocative headlines, the teenagers are not at risk of any health effects related to BPA. As important as it may be, that conclusion probably wouldn't have sold many newspapers.