Carbazole and polyhalogenated carbazoles in the marine environment around the Zhoushan Archipelago: Distribution characteristics, environmental behavior, and sources

The distribution characteristics and drivers of carbazole (CZ) and polyhalogenated carbazoles are still poorly understood. In this study, 96 samples were collected around the Zhoushan Archipelago, and their distribution characteristics were assessed. The results showed that CZ, 36-CCZ, and 36-BCZ were the top three abundant congeners in most collected samples. The bioaccumulation analysis revealed that marine plants prefer to accumulate CZ and bromocarbazoles rather than chlorocarbazoles. Both the mean concentrations of total carbazole and its derivants (ΣCZDs), as well as individual congeners, are the highest in sediments around the berthing areas of cargo ships and oil tankers. Meanwhile, ΣCZDs of these sediments are significantly influenced by the geo-weighted displacement of ships (r = 0.61; p