Can some plastics and chemicals like BPA and BPS be unsafe at any dose?

In the debate on plastics and endocrine disruptor chemicals safety, policy lags behind science

woman-and-child
In the debate on plastics and endocrine disruptor chemicals safety, policy lags behind science. Image by Lucas Hermann.

… ” the regulatory and industry approach to determine chemical safety has been to determine whether chemicals act like poisons – and generally not whether they act like hormones. And some scientists are concerned that this could lead to false conclusions of safety.” …

… ” A trillionth of a gram of a hormone in a milliliter of blood …is enough to alter the course of development of tissue in the fetus and lead to disease later on in life, Until plastics are tested at such minute levels, he says, we are in the dark about what levels of exposure are safe — especially for babies developing in the womb. ” …

Sept 2014 Study Abstract

Here we demonstrate that Bisphenol A  (BPA) exposure during a time point analogous to the second trimester in humans has real and measurable effects on brain development and behavior. Furthermore, our study is the first, to our knowledge, to show that bisphenol S, a replacement used in BPA-free products, equally affects neurodevelopment. These findings suggest that BPA-free products are not necessarily safe and support a societal push to remove all structurally similar bisphenol analogues and other compounds with endocrine-disruptive activity from consumer goods. Our data here, combined with over a dozen physiological and behavioral human studies that begin to point to the prenatal period as a BPA window of vulnerability, suggest that pregnant mothers limit exposure to plastics and receipts.

Jan 2014 Study Abstract

We measured serum dBPA in non-pregnant and pregnant female rhesus monkeys, fetuses and amniotic fluid. dBPA was administered by a daily oral bolus or sc implantation of Silastic capsules; both resulted in daily average serum unconjugated dBPA concentrations of <1ng/ml. We observed lower serum concentrations of unconjugated dBPA in pregnant females relative to pre-pregnancy values, and generally lower concentrations in fetal serum than in maternal serum. Differences in pharmacokinetics of dBPA were evident between pre-pregnancy, early and late pregnancy, likely reflecting changes in maternal, fetal and placental physiology. The serum ratio of conjugated to unconjugated dBPA after continuous sc release of dBPA was similar to values reported in human biomonitoring studies and markedly lower than with oral administration, suggesting oral bolus exposure is not an appropriate human exposure model. We report elsewhere that there were numerous adverse effects on fetuses exposed to very low serum dBPA in these studies.

Sources and more information
  • Very easy to read and very well documented, full of link studies links, read In The Debate On Plastics Safety, Policy Lags Behind Science, SoundMedicine, APR 13, 2015.
  • Bisphenol A (BPA) pharmacokinetics with daily oral bolus or continuous exposure via silastic capsules in pregnant rhesus monkeys: Relevance for human exposures, NCBI PMID:24582107, 2014 Jun;45:105-16 , sciencedirect, doi:10.1016/j.reprotox.2014.01.007, Reproductive Toxicology, Volume 45, June 2014.
  • Low-dose exposure to bisphenol A and replacement bisphenol S induces precocious hypothalamic neurogenesis in embryonic zebrafish, pnas, doi: 10.1073/pnas.1417731112, September 16, 2014.

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