The Hidden Persistence of Deep-Sea Pollution

T he actual persistence of a chemical is determined not only by its chemical structure but also particularly by its journey once it enters the environment, as it can encounter diverse environmental conditions affecting abiotic and biotic degradation, such as radiation, radical concentrations, or microbial communities.The widespread occurrence of organic contaminants in the ocean, including plastics, is an indicator of their persistence, 1 as more labile contaminants will be degraded before reaching open sea waters.Over the past several decades, there have been clear advances in our knowledge of the occurrence, transport, and cycling of a wide range of anthropogenic chemicals in the ocean, not only for legacy persistent organic pollutants, such as polychlorinated biphenyls (PCBs), but also for perfluoroalkyl substances (PFAS), organophosphate esters, and plastics, among others. [1][2]2][3][4][5] Most of these measurements were taken for the surface ocean, generally in the top several meters of the ocean.These