Research links prenatal exposure to phthalates to reduced lung function in childhood

A study by the Barcelona Institute for Global Health (ISGlobal) found that exposure to phthalates in the womb is associated with reduced lung function in childhood. The results of the study published in Environmental pollutionsupport the current European Union restrictions on the use of these substances.

There are phthalates chemical compounds which are widely used as plasticizers and in lacquers and varnishes. They are found in a wide variety of consumer products, from toys to food packaging, clothing, detergents, cosmetics, solvents, etc. Over time, the phthalates in these products end up in the environment, such as air, dust, and food , which makes them practically ubiquitous. Moreover, human exposure to phthalates begins in utero, given that these compounds are able to penetrate the placental barrier. Phthalates act as endocrine disruptors and have been linked to numerous developmental and reproductive health problems.

“Studies consistently find that gestational phthalate exposure is associated with an increased risk of childhood asthma, but evidence for its possible link to lung function is scarce and unclear,” explained ISGlobal researcher Magda Bosch de Basea, lead author of the study.

The study included 641 mother-child pairs with INMA project birth cohorts in Sabadell and Gipuzkoa. Gestational exposure to phthalates was analyzed using urine samples collected from the mother during pregnancy. Children’s lung function was assessed using spirometry at different stages of development between the ages of four and eleven.

As a sign of the ubiquity of these compounds, laboratory analyzes revealed all nine phthalate metabolites studied—i.e. substances into which phthalates are transformed after metabolism in the human body — in almost 100% of the studied urine samples. At all stages of development, the metabolites studied were associated with a decrease in two parameters of lung function: forced vital capacity (FVC), which measures the maximum volume of air that a person can exhale, and forced expiratory volume in 1 second (FEV₁), which measures maximal expiratory volume in the first second of exhalation.

However, the researchers found that the association between some metabolites (such as MiBP and MBzP) and decreased lung function tended to be statistically significant only at a young age, but not in spirometry conducted in later years. This pattern is consistent with results from studies in animal models, which suggest that the possible effects of these compounds on lung function recover over time.

Moreover, using statistical methods which accounts for exposure to mixtures of compounds, the study identified MBzP as an important contributor to the observed effects on lung function. “This leads us to believe that this metabolite—MBzP—may be a major contributor to the observed association with reduced lung function in childhood,” commented Judith García-Eymerich, head of ISGlobal’s Noncommunicable Diseases and Environment Program and senior co-author of the study.

“The use of some phthalates is already banned in some consumer products in the European Union. Although the associations observed in our study are relatively small in magnitude, the ubiquity of these substances and their known effects as endocrine disruptors in children lead us to suggest that these regulations should be extended to additional phthalates and to those countries that do not yet apply these restrictions,” concluded ISGlobal researcher Maribel Casas, senior co-author of the study.

The nine phthalate metabolites studied are as follows: MEP, MiBP, MnBP, MCMHP, MBzP, MEHHP, MEOHP, MECPP, and MEHP.

Prenatal exposure to BP3 is associated with body mass index and blood pressure

A second study, recently published in Internationalfound an association between prenatal exposure to benzophenone-3 (BP3) and higher body mass index and diastolic blood pressure at age 11 years.

BP3 is a common ingredient in cosmetics and sunscreens because of its UV light filtering qualities. However, it is also an an endocrine disruptor which belongs to the group of phenols.

The study aims to assess whether prenatal exposure to phthalates and phenols was associated with higher body mass index and blood pressure in adolescence. For this, the researchers used data on 1,015 people mother-child pairs from the birth cohort of the INMA project. Exposure to eight phthalate metabolites and six phenols was analyzed by examining urine samples collected during the first and third months of pregnancy; Body mass index and blood pressure were recorded when children reached 11 years of age.

No other association was detected with any of the other compounds tested, nor for the total mixture of compounds. In the case of BP3, the associations were observed most consistently in the preadolescent period that reached the onset of puberty.

“Along with the fetal and neonatal stages, puberty is considered one of the developmental windows in which the effects of endocrine disruptors “, said ISGlobal researcher Nuria Guil, lead author of the study. “Our findings shed light on the potential effects of BP3 on metabolism during puberty and highlight the need for stricter regulations on the use of this compound in certain products.”