Micro- and Nanoplastics: Where Are They and Why Are They Toxic?

Please join Yale Chemistry for a Biophysical Student-Invited seminar with Prof. Wei Min, Department of Chemistry, Department of Biomedical Engineering, from Columbia Univeristy. Abstract: Plastic pollution has emerged as a global environmental and health challenge, and its smallest fragments — micro- and nanoplastics — are now being detected throughout the human body and associated with multiple disease states. Yet two fundamental biophysical questions remain: How can we detect particles at the nanoscale, and why should fragments of chemically inert polymers become biologically active? I will first describe stimulated Raman scattering microscopy for rapid, chemically specific imaging of individual nanoplastics, including our discovery of more than 200,000 plastic particles per liter in bottled water, the vast majority in the nanoscale range. The second story begins with a paradox: plastics are considered chemically inert, so why should tiny fragments become biologically active? Surprisingly, the answer may lie not in the plastic alone, but in the water at its surface. At the plastic–water interface, altered hydration can enable electron transfer and reactive oxygen species generation, leading to protein aggregation and cellular injury even before particle uptake. Together, these two stories connect nanoscale measurement with mechanism and point toward a broader research frontier: understanding how interfacial water can endow otherwise inert materials with biological activity, with implications for human health, environmental science, and the design of safer materials. Bio: Wei Min received his B.S. from Peking University in 2003 and Ph.D. from Harvard University in 2008 studying single-molecule biophysics with Prof. Sunney Xie. After continuing his postdoctoral work in Xie group, Dr. Min joined the faculty at Columbia University in 2010, and was promoted to Full Professor there in 2017. He is also affiliated with Department of Biomedical Engineering, and Kavli Institute for Brain Science. Dr. Min's contribution has been recognized by a number of honors, including Biophotonics Technology Innovator Award from SPIE (2023), Raman Award for the Most Innovative Technological Development (2022), Craver Award of Vibrational Spectroscopy (2022), Scientific Achievement Award from Royal Microscopical Society (2021), Pittsburgh Conference Achievement Award (2019), Analyst Emerging Investigator Lectureship (2018), Coblentz Award of Molecular Spectroscopy (2017), the ACS Early Career Award in Experimental Physical Chemistry (2017), Camille Dreyfus Teacher-Scholar Award (2015), Alfred P. Sloan Research Fellowship (2013), and NIH Director's New Innovator Award (2012). Sponsored by the Biophysical Training Grant.