Pilot: Center for Appalachian Research in Environmental Sciences: Nanoplastics in Human Aqueous Fluid

Plastic waste contamination of our lands, waters, atmosphere, and food system is being increasingly recognized as a primary environment health concern. The citizens of Kentucky are becoming more aware of the impact of single-use plastics. During the 2020 legislative session, “plastic ban” bills were filed in both the House (HB81-Marzian) and Senate (SB68-Harper Angel).1 Although neither ultimately passed, this issue remains an environmental focus on an international level. Recent research overwhelmingly demonstrates the presence of exogenous plastic particles in our food supply, including the animals common to the Western diet. There is no reason to speculate humans are sheltered from contamination given the burden of exposure and anatomic similarities; however, the presence of unintended plastic particles in the human body has yet to be identified, either at the micro or nanoscopic level. As a result, it is neither currently possible to determine any impact of plastic on human health, nor future potential goals of treating and mitigating exposure. Using high-precision spectroscopic technology, we hypothesize that nanoplastics are detectable in human tissue, specifically the aqueous humor of the eye. The reliable identification of nanoplastics in human samples is currently challenging because the tissue samples have a complex biological background that is not too dissimilar from the plastic particles themselves. Aqueous fluid is unique and ideally suited for this endeavor because it is transparent, acellular, and immune privileged. This tissue does not only provide the least complicated sampling matrix, but because of the immunology of the eye, it is more difficult for non-native endogenous and exogenous substances alike to enter this space; if nanoplastics are identified in aqueous, they logically should be located in all tissues and organ systems. To initially test this, we completed an Institutional Review Board approved pilot project Figure 1. Scanning utilizing a National Nanotechnology Coordinated Infrastructure Seed Grant ($2,00) to electron micrograph of evaluate for the presence of nanoplastics in human aqueous (the fluid inside the eye) of a microparticle samples from two individuals. Utilizing Scanning Electron Microscopy (SEM), we identified remaining on a lacy particles of roughly 1 micrometer or less in size in all samples collected (Figure 1). We are carbon support of a now asking for additional funding to answer fundamental questions on their identification, chemical structure, and prevalence in humans. Our specific aim is designed to: Develop a method to enrich particles in aqueous for reliable analysis and optimize the nanoplastic detection methodology to provide a reliable, reproducible means of identifying and confirming nanoplastics in aqueous samples and verify that isolated nanoparticles are indeed nanoplastics. Standard techniques to characterize the structure and chemical composition of nanoparticles will be utilized, including energy-dispersive x-ray spectroscopy, micro-Raman, spectroscopy, and/or micro-Fourier transform infrared spectroscopy. The multidisciplinary collaborators are faculty in three different colleges (Engineering, Arts & Sciences, and Medicine) across the University of Kentucky, and although each have significant experience and productivity in their respective fields, translational environmental health is a new venture for all. These findings will create multiple additional funding and collaboration opportunities. Given the rising attention this topic is receiving, these results will strengthen advocacy efforts and attempts to change policy and industry standards, both locally and globally. 1