In an article published on July 12, 2022, in the International Journal of Environmental Analytical Chemistry, Ifeanyi Adolphus Ucheana, and co-authors from the University of Nigeria, Nsukka, Nigeria, reported on the migration of bisphenol A (BPA, CAS 80-05-7) from epoxy-coated cans into malt drinks. For their analysis, Ucheana et al. acquired 36 epoxy cans from a beverage manufacturer in Nigeria in April 2020 and performed migration experiments into malt drinks at refrigeration (approximately 4 °C), room temperature (approx. 25 °C), and sunlight (approx. 31 °C) conditions for 3, 7, 15, and 30 days. After solid-phase extraction, they analyzed BPA levels using high performance liquid chromatography coupled to an ultraviolet detector (HPLC-UV).
The scientists detected BPA in all samples at levels of 0.0166 – 0.0300 μg/L, 0.0188- 0.0788 μg/L and 0.0217 – 0.2131 μg/L at 4, 25, and 31 °C, respectively. Accordingly, BPA migration increased with temperature. BPA was also detected in the control sample, malt drink stored in glass, but in a concentration of 0.0048 µg/L. Looking at BPA migration over time showed that the migration rate increased with exposure duration for the two lower temperatures while at the highest temperature the rate decreased first and only increased after a longer exposure duration.
Based on the concentrations measured in the samples, the researchers also calculated the chronic daily intake (CDI) and compared it with the acceptable daily intake (ADI) of 4 mg/kg body weight per day. Since the CDI was below the ADI they concluded that “the levels of human exposure to BPA in canned malt drink assessed in this study were still low to constitute any risk to consumers.” However, they also emphasized that still “the ability of BPA to bioaccumulate and the potential additive effects from consumption of other food contact materials containing BPA is a cause for concern.” Moreover, in December 2021, the European Food Safety Authority (EFSA) proposed to lower the tolerable daily intake of BPA from 4 µg/kg body weight/day to 0.04 ng/kg body weight/day (FPF reported).
In an article published on July 17, 2022, in the journal Packaging Technology and Science, Wei Meng from the University of Science and Technology, Beijing, China, and co-authors analyzed BPA as well as the BPA alternatives bisphenol S (BPS, CAS 80-09-1), bisphenol F (BPF, CAS 620-92-8), and bisphenol AF (BPAF, CAS 1478-61-1) in packaged water and honey samples. In a first step, the researchers established and verified a ultrasonic-assisted dispersive liquid–liquid microextraction method to allow simultaneous detection of the four bisphenols in beverages. Subsequently, they applied the method to 34 “real” samples purchased in local supermarkets in Bejing, China. Samples included 13 drinking waters packaged in polycarbonate (PC) or polyethylene terephthalate (PET), eight soda samples packaged in PET or metal, as well as 13 honey samples packaged in PC, PET, or an unknown plastic type.
Meng and co-authors detected bisphenols in all sample types, the drinking water, the soda water, and the honey, but in varying amounts depending on the individual sample and the bisphenol. Concentrations were highest in the honey samples with BPF in 12 out of the 13 samples in levels of up to 766.7 µg/kg, BPS in six samples and levels of up to 209.09 µg/kg, and BPAF in eight samples and in levels up to 197.7 µg/kg. BPA was detected in four drinking water samples and one soda sample in concentrations of up to 1.08 µg/L and 11.40 µg/L, respectively. Concerning the packaging type, bisphenols were found to be present in samples packaged in all studied packaging types., i.e., PC, PET, metal, and unknown plastic. The authors think that their “established method was simple, effective, and ecofriendly” in comparison to other methods. Over the last years, several studies have reported the presence of BPA and its replacements in can coatings (FPF reported, here and here).
BPS is one bisphenol commonly used to replace BPA although it may be as harmful as BPA (FPF reported). Xu-Liang Cao and co-authors from Health Canada, Ottawa, Canada, aimed to assess whether BPS levels in meat have changed over the last 13 years. In their article published on July 20, 2022, in the journal Food Additives & Contaminants: Part A, they described that they collected 11 different meat and meat products in various Canadian cities between 2008 and 2020 and prepared the meat for consumption. They extracted the samples using acetonitrile and solid-phase extraction before chromatographic separation and analysis by mass spectrometry.
Cao and co-authors detected BPS in all beef steak, roast beef, ground beef, fresh pork, veal cutlets, lamb, and organ meats samples with the highest levels in fresh pork (105 ng/g) and veal cutlets (140 ng/g) from 2008. Therefore, they concluded that “the occurrence of BPS in meat is not a recent phenomenon.” Furthermore, BPS levels varied significantly in the samples taken over the 13 years but no time trend was observed. Accordingly, their findings would “not support the speculation that BPS is being used to replace BPA in food packaging.” The authors recommend investigating other sources than food packaging as sources of BPS.
In 2007, Coa and colleagues from Health Canada published a study in which BPA was detected in all 69 analyzed canned soft drinks sold on the Canadian market (FPF reported).
Catherine Pirard from the Laboratory of Clinical, Forensic and Environmental Toxicology, Liege, Belgium, and Corinne Charlier from the University of Liege, were also interested in temporal trends of bisphenol levels but assessed concentrations in human urine. Their article was published on July 9, 2022, in the journal Environmental Research. The two co-authors compared BPA, BPS, BPF, bisphenol Z (BPZ, CAS 843-55-0), and bisphenol P (BPP, CAS 2167-51-3) levels in 2015 and 2018 by analyzing the urine of 92 adult participants living in Liege, Belgium. All bisphenol alternatives “were measured in higher concentrations in 2018 vs 2015 while BPA levels did not differ significantly.”
Besides bisphenols, the researchers also measured levels of parabens, phthalate metabolites, and the phthalate substitute di(isononyl) cyclohexane-1,2-dicarboxylate (DINCH, CAS 166412-78-8). While DINCH metabolites concentrations were higher in 2018 than in 2015, paraben, and phthalate metabolite concentrations were by 1.3 to 2.5 fold lower (exception: monoethyl phthalate, MEP, CAS 2306-33-4). Between 2014 and 2016 an awareness campaign in Belgium aimed to inform the general population about the occurrence of endocrine disruptors, such as bisphenols, in consumer products along with their potential health risks. Pirard and Chalier reported that with their study outcomes “it was not feasible to unequivocally highlight an impact of the awareness campaign on the exposure levels of the population but one-third of the participants reported to have changed their habits to reduce their daily exposure to chemicals.”
References
Cao, X.-I. et al (2022). “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
Meng, W. et al (2022). “Determination of four bisphenols in plastic packaging beverages by ultrasonic-assisted dispersive liquid–liquid microextraction.” Packaging Technology and Science. DOI: 10.1002/pts.2677
Pirard, C. and Charlier C. (2022). “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. DOI: 10.1016/j.envres.2022.113852
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
