An analysis of data from more than 3,000 mother-child pairs from six European countries indicates that prenatal exposure to bisphenol A may have negative effects on respiratory health in school-age girls. The study was led by the Barcelona Institute for Global Health (ISGlobal).
Bisphenols are chemical substances used in the manufacture of plastics and resins found in many consumer products, such as food cans, reusable bottles and toys. The most well-known is bisphenol A (BPA), a known endocrine disruptor used widely in the manufacture of food containers and the interior coatings of such recipients.
The European Chemicals Agency (ECHA) included BPA on its list of substances of “very high concern” in 2017. Since then, some countries have limited its use, leading some manufacturers to replace BPA with other bisphenols.
“We believe the effect may be due to the fact that bisphenols can cross the placental barrier and interfere with the child’s respiratory and immune systems during the developmental phase,” said first author Alicia Abellán, a postdoctoral researcher at Barcelona Institute for Global Health.
There was a significant association between levels of BPA in mothers’ urine and asthma and wheezing for girls, but not boys, according to the study, published in the journal Environment International.
There could be several possible explanations for that finding, said study author Dr Leonardo Trasande, director of environmental paediatrics at NYU Langone Health.
“BPA is a synthetic oestrogen, and sex hormones shape nearly every bodily function during foetal development,” Trasande told CNN.
“When a baby is growing in utero, the lung buds are shaped by a host of factors of which sex hormones are one, so if there’s an imbalance of sex hormones induced, for example, by an exogenous oestrogen like BPA, that could be part of the story,” he said.
“BPA also contributes to inflammation and disrupts immune function. So a number of patterns could fit the story,” he added.
One of the largest studies done on the topic, the report’s results clarify prior research in smaller populations that showed an inconsistent association between BPA and respiratory disorders, Trasande said. The six countries in the study were Spain, France, Greece, Norway, The Netherlands and the United Kingdom.
“The limited study design is based on single samples to measure exposure and therefore is not capable of establishing a causal relationship between BPA and childhood asthma or wheeze. It is problematic to draw any meaningful conclusions from this report,” said Jennifer Garfinkel, director of product communications for the American Chemistry Council, which represents the chemical industry.
Can linings and thermal paper
One of the most studied bisphenols, BPA is a known endocrine disruptor, capable of altering hormones in the body. Foetuses and babies are especially vulnerable: BPA has been linked to foetal abnormalities, low birth weight, and brain and behaviour disorders in infants and children.
In adults, BPA has been linked to diabetes, heart disease, cancer, obesity and erectile dysfunction. Premature death was also associated with BPA exposure, a 2020 study found. People who had higher levels of bisphenol A in their urine were about 49% more likely to die during a 10-year period.
Around since the 1950s, bisphenol A can be found in beverage containers, the lining of canned foods, dental sealants and many toys, according to the US Centers for Disease Control and Prevention (CDC). The chemical was used to create baby bottles, “sippy” cups and infant formula containers until concerned parents boycotted those products more than a decade ago. The US Food and Drug Administration (FDA) responded with a 2012 ban on use in baby bottles and sippy cups, followed by a 2013 ban on use in infant formula packaging.
However, the FDA has not banned use of BPA in other food products, saying “the available information continues to support the safety of BPA for the currently approved uses in food containers and packaging”.
Only BPA connected to asthma
Urine samples were collected from pregnant women in the study between 1999 and 2010, when BPA was commonly used. The study found BPA in 90% of maternal urine samples taken during pregnancy.
Children born to those mothers had their lungs tested by spirometry between the ages of 7 and 11; mothers filled out questionnaires on their child’s wheezing and lung function. Of the several bisphenols analysed, BPA was the only one associated with respiratory symptoms such as asthma and wheezing during elementary school age, according to the study.
“The result is quite significant and seems to align with the latest European Food Safety Authority (EFSA) re-evaluation of the risk to public health related to BPA exposures,” said independent consultant Maricel Maffini, a biological scientist who has published studies on bisphenols and was not involved with the study.
“EFSA identified the immune system as the most sensitive health outcome associated with BPA toxicity. It included effects such as asthma, allergy, and wheeze, among others,” Maffini added.
The researchers also examined bisphenol F and bisphenol S, which manufacturers sell as “BPA-free” plastic substitutes that are intended to be safer than BPA. The study found extremely low levels of BPF and BPS in urine samples and did not find any consistent associations with respiratory outcomes. That’s possibly because the study was conducted before those alternatives became widely available, Trasande said.
However, research in animals is finding the same effects on prenatal development from BPS, linking it to problems with embryonic development and premature birth. Studies are also finding links to disruptions in the thyroid hormone system and heart arrhythmia.
How to avoid BPA
Today, BPA exposure is mostly through food and water contaminated by the linings of aluminium cans and beverages, followed by exposure to the thermal paper used to create shopping receipts, Trasande said.
You can limit your exposure by avoiding plastics as much as possible, he said. When using plastics, never put them in a microwave or dishwasher, because the heat can break down the linings and make them more easily absorbed. Other tips include:
• Cook at home often to reduce your use of processed foods.
• Use unscented lotions and laundry detergents.
• Use cleaning supplies without scents.
• Use glass, stainless steel, ceramic or wood to hold and store foods.
• Buy fresh or frozen fruits and vegetables instead of canned and processed versions.
• Encourage frequent handwashing to remove chemicals from hands.
• Avoid air fresheners and all plastics labelled as No. 3, No. 6 and No. 7.
In utero exposure to bisphenols and asthma, wheeze, and lung function in school-age children: a prospective meta-analysis of 8 European birth cohorts
Alicia Abellan, Sara Mensink-Bout, Raquel Garcia-Esteban, Andrea Beneito, Leda Chatzi, Talita Duarte-Salles, Mariana Fernandez, Judith Garcia-Aymerich, Berit Granum, Carmen Iñiguez, Vincent Jaddoe, Kurunthachalam Kannan, Aitana Lertxundi, Maria-Jose Lopez-Espinosa, Claire Philippat, Amrit Sakhi, Susana Santos, Valérie Siroux, Jordi Sunyer, Leonardo Trasande, Marina Vafeiadi, Fernando Vela-Soria, Tiffany Yang, Carlos Zabaleta, Martine Vrijheid, Liesbeth Duijts, Maribel Casas.
Published in Environment International on 18 March 2022.
In utero exposure to bisphenols, widely used in consumer products, may alter lung development and increase the risk of respiratory morbidity in the offspring. However, evidence is scarce and mostly focused on bisphenol A (BPA) only.
To examine the associations of in utero exposure to BPA, bisphenol F (BPF), and bisphenol S (BPS) with asthma, wheeze, and lung function in school-age children, and whether these associations differ by sex.
We included 3,007 mother–child pairs from eight European birth cohorts. Bisphenol concentrations were determined in maternal urine samples collected during pregnancy (1999–2010). Between 7 and 11 years of age, current asthma and wheeze were assessed from questionnaires and lung function by spirometry. Wheezing patterns were constructed from questionnaires from early to mid-childhood. We performed adjusted random-effects meta-analysis on individual participant data.
Exposure to BPA was prevalent with 90% of maternal samples containing concentrations above detection limits. BPF and BPS were found in 27% and 49% of samples. In utero exposure to BPA was associated with higher odds of current asthma (OR = 1.13, 95% CI = 1.01, 1.27) and wheeze (OR = 1.14, 95% CI = 1.01, 1.30) (p-interaction sex = 0.01) among girls, but not with wheezing patterns nor lung function neither in overall nor among boys. We observed inconsistent associations of BPF and BPS with the respiratory outcomes assessed in overall and sex-stratified analyses.
This study suggests that in utero BPA exposure may be associated with higher odds of asthma and wheeze among school-age girls.
Environmental International article – In utero exposure to bisphenols and asthma, wheeze, and lung function in school-age children: a prospective meta-analysis of 8 European birth cohorts (Creative Commons Licence)
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