Study On The Port And Ship Emissions And Their Environmental Impact And Health Risk

Ningbo-Zhoushan Port is the world's largest port and it's cargo throughput ranks NO.1 in 2015.The busy port operations and shipping produce a large number of air pollutants,which affects the air quality and human health.Studying the port and ship emissions in Ningbo,evaluating the emissions' impact on the atmospheric environment and their health risk is meaningful.Here we utilize the local activity data and some measured emission factors to develop the port emission inventory of Ningbo city,analyze the status and characteristics of the port and ship emissions in Ningbo,evaluate their influence on the air quality quantitatively by model simulation.Besides,we take use of several indicators to estimate the healthy risk of air pollutants in Ningbo.The main results are as follows:Firstly,the emission inventories of ports and ships are established.In 2015,the SO2,NOx,PM10,PM2.5,CO and VOCs emitted by Ningbo ports and ships are 16 400 tons,37 500 tons,2 800 tons,2 300 tons,2 300 tons,and 8 400 tons,respectively.The emission of SO2,NOx,PM10,PM2.5 and CO of ships are much larger than those of ports.Besides,the SO2 and NOx emissions from ships occupy an important proportion in the whole city,the proportion of which is 13.7%and 19%,respectively.For port operation machinery,the contribution of the emission from frame crane's movement is more than 85%.For transporting vehicles,the emission of container lorry contributes the most,over 90%.Besides,dust emission from storage yards and the surrounding roads is the main dust source in harbor district.Moreover,the annual emission of VOCs from liquid bulk's storage and transportation process in the port area is about 7 500 tons.According to the shipping emission calculation using Automatic Identification System(AIS)data,the SO2,NOx,PM10,PM2.5 and CO emissions of ships in Ningbo are 16 400 tons,36 600 tons,2 300 tons,2 200 tons,2200 tons and 800 tons,respectively.And cargo ships are the largest contributors to ship emissions.Secondly,WRF-CMAQ is utilized to evaluate the impact of port and ship emissions on the atmospheric environment.The simulation results show that the concentrations of SO2,NO2,PM10,PM2.5 and CO in the atmosphere are increased by port and ship emissions,with an average annual impact of 20.07%,27.12%,3.30%,5.32%and 0.82%,respectively.And the contribution of ship emissions is greater,accounting for more than 70%of the combined effects of ports and ships.For O3,in January,April and October,the emission of ships results a slight decrease of it in Ningbo,which may due to the titration effect related to NOx.However,in July,the emission of ships results a slight increase of O3,which could due to the strong ultraviolet radiation,a favorable condition for the formation of O3.Compared with SO2,NO2 and CO,the emissions of air pollutants from the port have greater impacts on particles and ozone in the atmosphere.Finally,the possible impacts of air pollution on human health in Ningbo are analyzed.The health risk of atmospheric environment in Ningbo is low in 2015 assessed by the air quality health index(AQHI),and the low risk days in the whole year exceed 90%.The effect of outdoor air pollution on daily mortality in Ningbo is estimated based on the concentration-response relationship between the air pollutants and mortality obtained by single-pollutant models.The results show that 482 premature deaths in Ningbo in 2015 are related to SO2 pollution,163 premature deaths are related to NO2,147 premature deaths are related to PM10,and 286 premature deaths are related to PM2.5.Besides,people over 65 years old are sensitive to air pollution and their premature deaths account for more than 80%of the total excess deaths.The contribution of port and ship emissions to the number of excess deaths related to air pollutants in the whole year is 3.7%to 20.4%.This study indicates that dust emission from the storage yards and the surrounding roads is the main source of port particulates,and the VOCs leakage of the port liquid bulk increases the level of ozone in the atmosphere.Compared with the major domestic port cities like Qingdao,Hongkong and Shanghai,it is found that the ship emission contributes greatly to SO2 and NO2 in port cities.Thus,port cities should pay high attention to the air pollution prevention and control of the air pollutant emissions from ports and ships,so as to improve the urban air quality and reduce the risk of human health.