Identification and quantification of shipping emissions in Bohai Rim, China

Rapid development of port and shipbuilding industry in China has badly affected the ambient air quality of coastal zone due to shipping emissions. A total of 60 ambient air samples were collected from background site of Tuoji Island in Bohai Sea strait. The air samples were analyzed for PM_2.5, organic carbon (OC), element carbon (EC), inorganic elements, and water-soluble ions. The maximum concentration of PM_2.5 was observed during spring (73.6μg·m^-3) compared to winter (39.0μg·m^-3) with mean of 54.6μg·m^-3. Back trajectory air mass analysis together with temporal distribution of vanadium (V) showed that V could be the typical tracer of shipping emissions at Tuoji Island. Furthermore, the ratios of vanadium to nickel (V/Ni), vanadium to lead (V/Pb) and vanadium to zinc (V/Zn) also suggest shipping emissions at Tuoji Island. The annual average primary PM_2.5 estimate of shipping emissions was 0.65μg·m^-3 at Tuoji Island, accounting for 2.94% of the total primary PM_2.5, with a maximum of 3.16% in summer and a minimum of 2.39% in autumn.