Assessment of the spatial and temporal distribution of legacy persistent organic pollutants and recommendations for sample collection from the surficial sediments of estuaries and seas in China

With the rapid economic development in China, environmental pollution has become a major concern, particularly pollution by persistent organic pollutants (POPs). Thus, these pollutants must be monitored over the long term. In this study, we analyze the distribution levels and sources of POPs in the surficial sediments of Chinese estuaries and seas. Results showed that POPs in sediments significantly distribute spatially and temporally. Furthermore, POPs not only concentrate in densely populated cities, bays, and industrial areas, but also follow the natural distribution of and temporal changes in local industrial structures. Hence, we recommend sampling sites and frequencies to monitor POPs in China over the long term and to defer their analysis.