The 35th annual A&WMA Critical Review addresses the broad topic of nanoparticles and the environment. Complementing recent treatments of this topic in the literature, the review offers a broad overview of environmental origins, consequences, and applications of nanoparticles, or particles with diameters in the range of 1 to 50 or 100 nanometers. The four key elements discussed in the review are (1) sources of nanoparticles, (2) their control, (3) the application of nanoparticles in environmental and energy sectors, and (4) exposure and health effects. 18 refs., 4 figs., 1 tab.