Broad Range of Pollutants Found in 10 Brands Altogether, the analyses conducted by the University of Iowa Hygienic Laboratory of these 10 brands of bottled water revealed a wide range of pollutants, including not only disinfection byproducts, but also common urban wastewater pollutants like caffeine and pharmaceuticals (Tylenol); heavy metals and minerals including arsenic and radioactive isotopes; fertilizer residue (nitrate and ammonia); and a broad range of other, tentatively identified industrial chemicals used as solvents, plasticizers, viscosity decreasing agents, and propellants. The identity of most brands in this study are anonymous. This is typical scientific practice for market-basket style testing programs. We consider these results to represent a snapshot of the market during the window of time in which we purchased samples. While our study findings show that consumers can't trust that bottled water is pure or cleaner than tap water, it was not designed to indicate pollutant profiles typical over time for particular brands.