Two recent peer-reviewed publications have used information gathered from the US National Institutes of Health Environmental influences on Child Health Outcomes (ECHO) Program, a large biomonitoring study, to investigate the relationships between chemical exposures of pregnant women and subsequent birth outcomes. One of the studies focused on the impacts of phthalates and another on organophosphate ester flame retardants (OPEs).
Phthalates
Phthalates are a group of additives usually mixed into polymers to increase softening and flexibility. Additives that do this are known as plasticizers. In recent years phthalates, and some of the plasticizers used to replace them, have been under increasing scrutiny for causing adverse health effects including behavioral development, reproductive toxicity, and cardiovascular diseases (FPF reported, here and here).
On February 6, 2024, Leonardo Trasande of NYU Grossman School of Medicine and more than 15 other co-authors published a study investigating the relationship between 20 phthalate metabolites and gestational age at birth, birthweight, birth length, and birthweight for gestational age. They “also estimated attributable adverse birth outcomes and associated costs.”
Using a large sample size of 5006 mother–child pairs, the authors found that di-2-ethylhexyl phthalate (DEHP, CAS 117-81-7), diisodecyl phthalate (DiDP, CAS 26761-40-0), diisononyl phthalate (DiNP, CAS 28553-12-0), and di-n-octyl phthalate (DnOP, CAS 117-84-0) “were [all] associated with decreased gestational age and increased risk of preterm birth.” When extrapolated to the entire US population, this is equivalent “with 56,595 preventable preterm birth cases” annually.
Cost concerns are often highlighted as a reason why potentially hazardous chemicals may not be adequately replaced in food contact and other products. Thus, Trasande et al. went a step further by calculating the costs of these preterm births to the US health system. They found that “[t]he lost economic productivity and additional medical care costs due to phthalate-induced preterm births in 2018 alone ranges between $1.63 billion and 8.14 billion.”
This is in addition to the estimated $250 billion disease burden and costs of plastics in the US annually, published earlier this year (FPF reported).
All five of these phthalates, and many others, have been detected in food contact materials according to the Food Packaging Forum’s database on migrating and extractable food contact chemicals (FCCmigex). DEHP is the most well-studied of the phthalates in food contact materials and has been under the most pressure to be replaced. Trasande’s and other studies (FPF reported) demonstrate how looking at chemicals one at a time can lead to regrettable substitution.
Organophosphate esters
OPEs are used to substitute brominated flame retardants and, like ortho-phthalates, may also act as plasticizers. These chemicals can transfer into a developing fetus from the placenta and umbilical cord.
On January 24, 2024, Jiwon Oh of the University of California Davis and co-authors published their investigation of birth outcomes from gestational OPE exposure in Environmental Health Perspectives. From a very large sample size of 6,646 pregnancies in the ECHO program, Oh et al. investigated nine OPE biomarkers in urine and their association with gestational length and birthweight.
More than 85% had detectable biomarker levels for dibutyl phosphate (DBUP, CAS 107-66-4), di-isobutyl phosphate (DIBP, CAS 1189-24-8), and bis(1,3-dichloro-2-propyl) phosphate (CAS 77236-72-7) in their urine.
Higher levels of DBUP, DIBP, and bis(butoxyethyl) phosphate (CAS 14260-97-0) were linked with a greater chance of early birth. While a combined metric of DBUP, DIBP, and greater levels of bis(2-chloroethyl) phosphate (CAS 3040-56-0) were problematic for female babies. However, three OPEs were linked with higher birthweights which may indicate obesogenic effects.
OPE exposure has been linked to neurotoxicity and endocrine disruption (FPF reported). Paper packaging can be a source of these OPEs (FPF reported). In July 2023, researchers tentatively identified 42 OPEs in Chinese takeaway packaging (FPF reported), while extensive contamination in Chinese foodstuff has also been documented (FPF reported).
References
Trasande, Leonardo, et al. (2024). “Prenatal phthalate exposure and adverse birth outcomes in the USA: a prospective analysis of births and estimates of attributable burden and costs.” The Lancet. DOI: 10.1016/S2542-5196(23)00270-X
Oh, Jiwon, et al. (2024). “Associations of organophosphate ester flame retardant exposures during pregnancy with gestational duration and fetal growth: The environmental influences on child health outcomes (ECHO) program.” Environmental Health Perspectives. DOI: 10.1289/EHP13182
Read more
Sandee LaMotte (February 6, 2024). “Foods we eat are covered in plastics that may be causing a rise in premature births, study says.” CNN
Erin Prater (February 7, 2024). “Plastic-linked ‘hormone-disrupting chemicals’ were potentially behind 10% of U.S. preterm births in 2018, according to new research. How families can steer clear of their danger.” Fortune
