In an article published on June 30, 2022, in the journal Polymers, Antonio Ragusa from Università Campus Bio Medico di Roma, Italy, and co-authors analyzed human breastmilk for the presence of microplastics. The scientists collected breastmilk samples from 34 women who gave birth at a hospital in Rome without complications one week after delivery. The study participants also had to fill in a questionnaire providing details on their food consumption (with a focus on fish and shellfish) and use of packaging and personal care products for seven days before and after the expected date of delivery.
Using Raman microspectroscopy, Ragusa et al. detected microplastics in 26 out of the 34 samples. In total, they detected 58 microplastic particles, all of which had an irregular shape and half of which had a size between 4 and 9 µm. Concerning the material type, 38% were made of polyethylene (PE), 21% of polyvinyl chloride (PVC), and 17% of polypropylene (PP). Furthermore, food consumption habits and personal care product use were found to not affect microplastics’ presence.
Previously, microplastics have also been detected in the human placenta and meconium. Ragusa and co-authors concluded that “the evidence of microplastics in human breastmilk, coupled with the previous discovery of these microparticles in the human placenta, represents a great concern since it impacts the extremely vulnerable population of infants.” Moreover, they emphasized that further research is needed to increase the knowledge on potential health risks of microplastics, “especially in infants.”
Diqi Yang from Huazhong Agricultural University, Wuhan, China, and co-authors, aimed to understand whether and how micro- and nanoplastics affect the fetuses of mice. In an article published on June 18, 2022, in the journal Environment International, they reported that they orally fed five mice with 1 mg green-fluorescent unmodified or carboxylated nanoplastic (100 nm) and/or microplastic (1 µm) beads from day one to seventeen of gestation. Subsequently, they investigated histological changes in maternal and fetal tissues, gene expression, the antioxidative capacity of placentas and fetal brains, γ-aminobutyric acid (GABA) in the amygdala, as well as behavioral changes.
The researchers observed both nano- and microplastics in the gastrointestinal tract, brain, uterus, and placenta of pregnant mice while nanoplastics were also able to cross the placental barrier entering the fetal brain, and here the thalamus in particular. When co-exposed with microplastics, the levels of unmodified and carboxylated nanoplastics in the placenta and fetal brain were higher. The authors outlined that the plastic particles would “disrupt the blood-placental barrier by inducing [reactive-oxygen species-] ROS-mediated cell apoptosis.” The nanoparticles were further found to change gene expression in the fetal thalamus as well as to induce the production of ROS and neuronal apoptosis. Using N2A murine neuroblastoma cells, the scientists verified “the oxidative damage of polystyrene nanoparticles to neural cells.” Moreover, they observed that the progeny of the exposed mice showed anxiety-like behavior. Yang and co-authors concluded that “polystyrene nanoparticles have a negative impact on fetal brain development through oxidative injury and GABA synthesis.”
Ragusa, A. et al (2022). “Raman Microspectroscopy Detection and Characterisation of Microplastics in Human Breastmilk.” Polymers. DOI: 10.3390/polym14132700
Yang, D. et al (2022). “Polystyrene micro- and nano-particle coexposure injures fetal thalamus by inducing ROS-mediated cell apoptosis.” Environment International. DOI: 10.1016/j.envint.2022.107362
This article was originally published by Lisa Zimmermann at the Food Packaging Forum.