Levels of bisphenol in packaging, food and urine are the subject of four scientific studies. Food Packaging Forum reports on this, where experts from academia, civil society, industry, regulators and the media work on science communication and research.
Bisphenol is an endocrine disruptor, altering hormonal and metabolic balances, as we have seen.
Bisphenol A in packaging, epoxy cans
A team of Nigerian researchers from the University of Nigeria, Nsukka, detected bisphenol A levels in 36 epoxy-coated cans used as malt beverage packaging.
Analyses were performed on the drinks after exposing the cans to three temperature levels (4, 25 and 31 °C) for 3, 7, 15 and 30 days.
The role of time and temperature
Evidence shows that BPA migration increases with higher temperature. Over time, however, the results reverse: migration increases over time at the two lowest temperatures, while at the highest temperature (31 °C, i.e., sun exposure) it first decreases and then increases.
Scientists detected BPA in all samples at levels ranging from 0.0166 to 0.2131 μg/L. Bisphenol was also found in the control sample, a malt beverage in a glass bottle, but at a lower concentration (0.0048 µg/L).
What daily dose
The values found are considered safe by researchers because they cause exposure below the acceptable daily intake (ADI) of 4 mg/kg body weight per day.
However, the study authors point out that ‘the ability of BPA to bioaccumulate and the potential additive effects of consuming other food contact materials containing BPA are cause for concern.’
This is also why, in December 2021, the European Food Safety Authority (EFSA) proposed to reduce the tolerable daily intake of BPA from 4 µg/kg body weight/day to 0.04 ng/kg body weight/day.
Four types of bisphenol in bottled water and honey
At the University of Science and Technology, Beijing, China, a team of researchers measured levels of four types of bisphenol (A, S, F, AF) in 34 samples of water and honey purchased in Beijing supermarkets.
The products analyzed are.
- Water bottled in polycarbonate (PC) or polyethylene terephthalate (PET),
- Soda (carbonated water) in PET or metal,
- Honey packaged in PC, PET or an unknown type of plastic.
Most contaminated honey
Analyses detected bisphenol in all types of samples, regardless of the type of packaging.
The highest concentrations are in honey samples contaminated with three types of bisphenol:
- BPF in 12 of the 13 samples, with levels as high as 766.7 µg/kg,
- BPS in six samples and levels up to 209.09 µg/kg and
- BPAF in eight samples and levels up to 197.7 µg/kg.
BPA was detected in four drinking water samples and one soda water sample, at concentrations up to 1.08 µg/L and 11.40 µg/L, respectively.
Bisphenol S in Canadian meat
Bisphenol S (BPS) is a bisphenol also commonly used in packaging to replace BPA although it can be equally harmful. Health Canada researchers found it in Canadian meat products marketed from 2008 to 2020, suggesting that BPS contamination is not a recent phenomenon much less related to packaging.
Researchers collected and analyzed 11 different meats and meat products in various Canadian cities between 2008 and 2020. Upon analyzing them, they found BPS in all samples of beef steak, roast beef, ground beef, fresh pork, veal cutlets, lamb, and organs.
Pork and veal most contaminated
Bisphenol levels have been highest in fresh pork (105 ng/g) and veal cutlets (140 ng/ g) since 2008.
The evidence shows that ‘the presence of BPS in meat is not a recent phenomenon‘ and calls for investigating other sources of contamination besides food packaging. (4)
Bisphenol in the urine of Belgians
In the Belgian study by Catherine Pirard of the Laboratory of Clinical, Forensic and Environmental Toxicology and Corinne Charlier of the University of Liège, the trend of bisphenol in the urine of the Belgian population in 2018 compared to 2015 is measured. (5)
Using biological material provided by 92 adults living in Liege, the researchers compared levels of BPA, BPS, BPF, bisphenol Z (BPZ) and bisphenol P (BPP) in 2015 and 2018.
The result showed that all bisphenol A alternatives ‘were measured in higher concentrations in 2018 than in 2015, while BPA levels did not differ significantly.’
Thus, it appears that bisphenol alternatives to BPA are adding to bisphenol A, rather than replacing it (moreover, without benefit).
Notes
(1) Lisa Zimmermann. Scientists explore international bisphenol levels in packaging, food, and urine. Food Packaging Forum., 5.8.22
(2) Ucheana, I. A. et al (2022). Migration of bisphenol A from epoxy-can malt drink under various storage conditions and evaluation of its health risk. International Journal of Environmental Analytical Chemistry. DOI: 10.1038/s41597-022-01365-8
(3) Wei Meng, Hongmei Li, Kaiqing Wang, Yanqiu Cao. Determination of four bisphenols in plastic packaging beverages by ultrasonic-assisted dispersive liquid-liquid microextraction. Packaging Technology and Science, 7/17/2022 https://doi.org/10.1002/pts.2677
(4) Xu-Liang Cao, Simon Zhou, Svetlana Popovic & Robert Dabeka. Temporal trend of bisphenol S occurrence in meat samples from 2008-2020 Canadian total diet study. Food Additives & Contaminants: Part A, DOI: 10.1080/19440049.2022.2099985
(5) C. Pirard, C. Charlier. Urinary levels of parabens, phthalate metabolites, bisphenol A and plasticizer alternatives in a Belgian population: Time trend or impact of an awareness campaign? Environmental Research, Volume 214, Part 2, 2022, https://doi.org/10.1016/j.envres.2022.113852.
Professional journalist since January 1995, he has worked for newspapers (Il Messaggero, Paese Sera, La Stampa) and periodicals (NumeroUno, Il Salvagente). She is the author of journalistic surveys on food, she has published the book "Reading labels to know what we eat".
