Endocrine toxicity and chemical composition of plastic products.

Besides the physical characteristics of plastic particles such as size or shape, the chemical composition of the plastic particle can contribute to its toxicity. Plastics are chemically highly complex products. For instance, more than 10,000 substances are intentionally used in the production of plastics (e.g., plasticizers, antioxidants) and even more non-intentionally added substances (e.g., reaction byproducts, impurities) are associated with them. While there is abundant scientific evidence that some chemicals used in plastics, such as bisphenols and phthalates, are endocrine disruptors, little is known about the composition and the toxicity of these complex mixtures of chemical. Therefore, this study aims at characterizing both using plastic food contact articles (FCA) as relevant sources of exposure to humans and the environment. Thirty-nine plastic FCAs covering the seven polymer types with the highest global waste share were extracted and analyzed with reporter gene assays for a set of nuclear receptors relevant for human health, including pregnane X receptor (PXR), peroxisome proliferator receptor gamma (PPARγ), estrogen receptors alpha (ERα) and androgen receptor (AR). Further, these plastic extracts were analyzed using non-target high-resolution mass spectrometry to quantify the number of chemical features and tentatively identify the chemicals present in the FCAs. The chemicals extracted from 36 out of 39 FCAs activated or inhibited one or more receptors with activities up to 100% of the respective reference compounds. The PXR was activated by 36, the PPARγ by 23, the ERα by 18 samples, while the AR was inhibited by 14 of 39 samples. In total, we detected >16 000 unique chemical features with the number of features per sample ranging from 37 to 10,000. Only 17% of the chemical features were tentatively identified using spectral libraries and in silico tools. This research highlights the importance of analyzing whole mixtures and contributes to improve our understanding of plastics as a source of exposure to endocrine disrupting chemicals.

Acknowledgement - This project has received funding from the European Union’s Horizon 2020 research and innovation program under grant agreement No 860720.