Environmental scientists continue to unravel the pervasive distribution and biological effects of micro- and nanoplastics. Studies highlight novel methods for detecting plastic particles in human blood and feces, raising concerns about direct human exposure pathways. Research also differentiates toxic effects of nano- versus microplastic particles on live algae and gut cells. Advances in analytical techniques including pyrolysis–gas chromatography–mass spectrometry and nuclear magnetic resonance spectroscopy improve methods for environmental quantification and risk assessment.