In the past century, humans have put 83,000 synthetic industrial compounds into the environment. 5000 of these chemicals are high production volume chemicals, produced at volumes of thousands of metric tonnes annually. We have also dramatically changed the environmental levels of natural harmful compounds such as carbon dioxide and mercury; indeed two-thirds of the mercury in the atmosphere today is from our use of coal for energy. Many modern industrial compounds, such as pharmaceuticals, perfluorocarbons (PFC; teflon) and polybrominated diphenylethers (PBDE; flame retardants), are highly persistent.
The oceans are a repository for global pollutants. In turn, our own exposure to these ocean pollutants is often directly linked to our consumption of seafood. For example, elemental mercury in the atmosphere is deposited in the oceans through atmospheric processes and converted to organic mercury by microbes in sediments. Organic mercury persists, by binding to intracellular proteins, and rapidly moves up the food chain where it accumulates to high levels in long-lived fish. In turn, we humans are exposed to mercury when we eat those fish. There is urgent need to measure the scale of the ocean pollution problem and to determine the extent to which it presents a threat to human and environmental health through consumption of seafood.