Researchers with Portland State University and Washington State University, Vancouver, have reportedly detected caffeine in waters off the coast of Oregon, raising questions about the presence of other potential contaminants in the vicinity. Zoe Rodriguez del Rey, et al., “Occurrence and concentration of caffeine in Oregon coastal waters,” Marine Pollution Bulletin, July 2012. The study apparently analyzed caffeine levels at 14 coastal locations “stratified between populated areas with sources of caffeine pollution and sparsely populated areas with no major caffeine pollution sources.” Although levels ranged from below the reporting limit of 8.5 nanograms per liter (ng/L) to 44.7 ng/L, the marine ecologists noted that “caffeine concentration did not correspond with human population density and pollution source.”  

“Our hypothesis from these results is that the bigger source of contamination here is probably on-site waste disposal,” said one of the study’s authors. “Wastewater treatment plants, for the most part, have to do with regular monitoring to ensure they are within certain limits.”  

Meanwhile, the findings have already attracted attention from other researchers, including one hydrologist with the U.S. Geological Survey’s Toxic Substances Hydrology Program. “Caffeine is pretty darn ubiquitous, and there is growing evidence that this and other understudied contaminants are out there,” Dana Koplin said. “[T]here is a whole universe of potential contaminants including pharmaceuticals, hormones, personal-care products like detergents or fragrances, even artificial sweeteners… Are there environmental or human-health consequences from exposure to these compounds or different mixtures of compounds? Obviously that’s the million-dollar question.” See National Geographic, July 30, 2012.