POPs are typically characterized as having low water solubility and high fat solubility. Most POPs are anthropogenic in origin. Anthropogenic emissions, both point and diffuse, are associated with industrial processes, product use and applications, waste disposal, leaks and spills, and combustion of fuels and waste materials. Once dispersed, clean-up is rarely possible. Because many POPs are relatively volatile, their remobilization and long-distance redistribution through atmospheric pathways often complicates the identification of specific sources.
POPs have long environmental half-lives.
Accordingly, successive releases over time result in continued accumulation and the ubiquitous presence of POPs in the global environment. The primary transport routes into the marine and coastal environment include atmospheric deposition and surface run-off. Regional and global transport is predominately mediated by atmospheric circulation, but also occurs through sediment transport and oceanic circulation. Movement may also occur through a successive migration of short-range movements that result from a sequence of volatilization, deposition, and revolatilization. Due to these transport patterns and chemical characteristics, there is a growing body of evidence demonstrating the systematic migration of these substances to cooler latitudes.