Is our exposure to BPA higher than we thought?

Researchers in the US have developed a more accurate method of measuring bisphenol A (BPA) levels in humans. Their results suggest that our exposure is much higher than was previously thought.

The research, published in The Lancet Diabetes & Endocrinology, measured BPA in human urine using a “direct” analytical method rather than the standard two stage test used by most laboratories. The results showed levels of BPA in test subjects to be up to 44 times greater than those obtained using the standard method (1).

This is a concern because BPA, a component of some plastics and until recently used in thermal till receipts, is classified as a Substance of Very High Concern by the EU, due to its hormone disrupting properties and reproductive toxicity. Evidence strongly suggests long-term BPA exposure increases risk of breast cancer and other illnesses. Exposure in utero is of particular concern.

In a published comment on the study, Breast Cancer UK grant recipients Kerri Palmer and Professor Valerie Speirs highlight the role of BPA as an oestrogen mimic as well as its ability to affect other sex hormones which may influence the risk of breast cancer and other hormone-related diseases.

According to Kerri Palmer “We’re concerned that widely accepted analytical methods may be underestimating the levels of BPA. The ubiquitous use of this chemical in everyday products means we may be continuously exposed at higher levels than previously thought throughout our lifetime. Being able to accurately determine BPA levels is fundamental to understanding its potential effects on human health.”

It may not only be BPA levels that are being underestimated. The same type of indirect technique is used to measure bisphenol substitutes (which are routinely replacing BPA in consumer goods) as well as other types of endocrine disrupting chemicals such as phthalates and parabens.

For more information on BPA see our brief here and our No more BPA campaign here

Notes:

(1) In the human body, orally ingested BPA is rapidly converted to BPA metabolites (BPA- glucuronide and BPA-sulphate) which are excreted in the urine. The standard method relies on these being converted back to free BPA, using an enzyme obtained from snails. It turns out this conversion step is less efficient than previously thought and so not all BPA metabolites are converted to free BPA. The new method measures the metabolites directly.

Gerona, R. et al. (2020). BPA: have flawed analytical techniques compromised risk assessments? The Lancet Diabetes & Endocrinology Correspondence Volume 8, Issue 1, p11-13, published January 01, 2020. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(19)30381-X/fulltext

Palmer, K. and Speirs, V. (2020). BPA and risk assessment. The Lancet Diabetes & Endocrinology Correspondence Volume 8, Issue 4, p269, published April 01, 2020. https://www.thelancet.com/journals/landia/article/PIIS2213-8587(20)30068-1/fulltext