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Does the risk exist? – bisphenol a and cadmium analysis of the polish diet

The prevalence of bisphenol A

Bisphenol A, commonly known as BPA, is a widely used component in the production of various items such as plastic packaging, bottles, and coatings in food cans. Its presence in everyday products that we come into contact with raises concerns due to potential health hazards. There are numerous studies aiming to understand how BPA affects our bodies, especially our hormonal system. The consequences of its exposure are a subject of increased interest and growing social awareness.

Bisphenol A, commonly referred to as BPA, constitutes a monomer and plasticizer (a substance that enhances the hardness and flexibility of polymers), with an annual production exceeding 2.72 billion kilograms [1]. It finds use across various industries, including the production of polycarbonate plastics, epoxy resins for lining cans, and in various plastic products, from toys to medical equipment and electronics [2].

However, its ubiquitous presence in everyday products is associated with significant health risks. BPA is detected in bodily fluids like serum and urine, and even in amniotic fluid, placental tissue, and umbilical cord blood. Concentrations of both free and bound BPA in bodily particles have been found to exceed safety thresholds for humans [3].

Laboratory studies and observations on populations suggest that substances structurally similar to BPA, known as xenoestrogens (estrogen-like substances that bind to receptors and can exert similar effects on the body as estrogen itself), may be linked to the development of reproductive system cancers (breast, uterus) and fertility disorders, as well as other hormonal conditions (endometrial diseases, PCOS) [3].

EU-FORA Food Risk Assessment Programme:

Under the 6th cycle of EU-FORA (European food risk assessment, 2022–2023), a fellow from the Department of Quality of Life Studies at the University of Bologna in Italy spent three months at the Department of Food Safety and Chemical Analysis at the Institute of Agricultural and Food Biotechnology in Warsaw, conducting research on the presence of various chemical contaminants in food products. A pivotal aspect was investigating the presence of BPA and cadmium in different population groups in Poland [4].

Regulations concerning BPA:

European regulations governing the presence of BPA in food allow for a content of 0.05 mg of BPA per kg of food. This restriction prompted producers to seek alternative substances, such as bisphenol F (BPF) and bisphenol S (BPS), which, although similar to BPA, are not yet legally regulated and could affect the hormonal system. To reduce the adverse effects of BPA exposure on health, in 2023, the EFSA CEP Panel established a new tolerable daily intake (TDI) of 0.0002 μg/kg body weight, replacing the previous provisional TDI of 4 μg/kg body weight set by the EFSA in 2015 [4].

Health concerns associated with BPA exposure:

Analyzing the potential health risks associated with BPA exposure through soft drink consumption, permissible TDI values for BPA were compared with values for chronic dietary exposure in various population groups. In all groups, exposure to BPA exceeded the TDI established by EFSA in 2023, raising health concerns. However, it is worth noting that the content of BPA in soft drinks falls below the maximum permissible limit of 0.05 mg per kg of food set by EU regulations [4].

Regarding exposure to cadmium due to consumption of milk and dark chocolate, tolerable weekly intake (TWI) for cadmium was compared with values for chronic dietary exposure in individual population groups. In all groups, observed cadmium exposure was lower than the TWI value established by EFSA in 2009, set at 2.5 μg/kg body weight. Therefore, chocolate consumption currently does not raise health concerns related to cadmium exposure [4].

BPA contamination in the environment

Unfortunately, we are exposed to BPA practically everywhere. The production of massive amounts of BPA annually allows this substance to infiltrate the environment in various ways.

In drinking water and water reservoirs:

While BPA exists in drinking water and water reservoirs, the quantities are minimal. The median content was 0.14 µg/l, with a maximum measurement of 12 µg/l [5].

In air and household dust:

Studies have shown the presence of BPA in 86% of household dust samples at concentrations ranging from 0.2 to 17.6 μg/g. Additional observations of BPA levels in urban air revealed average levels of 0.51 ng/m3. Interestingly, these concentrations exhibited mild seasonal variability [6,7].

In everyday use products:

BPA is even used as a fixing agent in paper production . An analysis of 20 different brands of kitchen paper towels (also known as kitchen rolls) found that extracts from paper towels made from primary paper did not contain BPA, except for one brand (at 0.12 mg/kg). However, BPA levels for paper towels made from recycled paper ranged from 0.55 to 24.1 mg/kg. In a second study examining 28 paper products intended for food contact, 67% of the 12 products made from recycled paper contained BPA within the range of 0.19-26 mg/kg [8,9].

In the human body:

Studies have identified the presence of BPA in urine, blood from pregnant women, fetuses, placentas, and amniotic fluid. This is particularly concerning as the developing fetus is particularly susceptible to hormonal influences and chemical exposures.

Metabolism of BPA

BPA has been frequently found in the range of several ng/ml in the urine of over 90% of individuals in several countries and continents. BPA has also been detected in the blood of pregnant women, fetal blood, umbilical cords, placentas, and amniotic fluid, which is very concerning as the developing fetus is susceptible to hormones and chemical exposures [3].

A study conducted by Volkel and his team [10] showed that administering 5 mg of radioactive BPA per person (54-90 g/kg body weight) led to the complete elimination of BPA from the body within 24 hours. The maximum serum concentration was reached after 80 minutes from administration and rapidly decreased over the next 6 hours. During analysis, BPA was detected only in its glucuronidated form, not as free BPA. These results suggest that in humans, BPA is rapidly absorbed from the gastrointestinal tract, conjugated with glucuronic acid in the liver, and then rapidly excreted from the body, with glucuronidated BPA filtered from the blood by the kidneys and excreted in the urine [10].

Is it possible to avoid BPA exposure?

Despite its widespread presence, limiting contact with items that potentially contain BPA may help reduce exposure (especially using glass containers). However, eliminating contact with BPA may be challenging due to its ubiquity in everyday surroundings.

Bibliography:

[1] Burridge E. Bisphenol A product profile. Eur Chem News 2003:14–20.

[2] https://www.efsa.europa.eu/en/topics/topic/bisphenol [access 28/12/2023]

[3] Laura N. Vandenberg; Russ Hauser; Michele Marcus; Nicolas Olea; Wade V. Welshons (2007). Human exposure to bisphenol A (BPA). , 24(2), 139–177. doi:10.1016/j.reprotox.2007.07.010

[4] (PDF) Threat or treat: Exposure assessment and risk characterisation of chemical contaminants in soft drinks and chocolate bars in various Polish population age groups. https://www.researchgate.net/publication/376094113_Threat_or_treat_Exposure_assessment_and_risk_characterisation_of_chemical_contaminants_in_soft_drinks_and_chocolate_bars_in_various_Polish_population_age_groups [accessed Dec 29 2023].

[5] Kolpin DW, Furlong ET, Meyer MT, Thurman EM, Zaugg SD, Barber LB, et al. Pharmaceuticals, hormones, and other organic wastewater contaminants in U.S. streams 1999–2000: a national reconnaissance. EnvironSci Technol 2002;36:1202–11.

[6] Matsumoto H, Adachi S, Suzuki Y. Bisphenol A in ambient air particles responsible for the proliferation of MCF-7 human breast cancer cells and its concentration changes over 6 months. Arch Environ Contam Toxicol 2005;48:459–66.

[7] Rudel RA, Camann DE, Spengler JD, Korn LR, Brody JG. Phthalates, alkylphenols, pesticides, polybrominated diphenyl ethers, and other endocrine-disrupting compounds in indoor air and dust. Environ Sci Technol 2003;37:4543–55.

[8] Vinggaard AM, Korner W, Lund KH, Bolz U, Petersen JH. Identification and quantification of estrogenic compounds in recycled and virgin paper for household use as determined by an in vitro yeast estrogen screen and chemical analysis. Chem Res Toxicol 2000;13:1214–22.

[9] Ozaki A, Yamaguchi A, Fujita T, Kuroda K, Endo G. Chemical analysis and genotoxicological safety assessment of paper and paperboard used for food packaging. Food Chem Toxicol 2004;42:1323–37

[10] Volkel W, Colnot T, Csanady GA, Filser JG, Dekant W. Metabolism and kinetics of bisphenol A in humans at low doses following oral administration. Chem Res Toxicol 2002;15:1281–7.

Biologiczny Hejted
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