In 2015, ship emissions increased summer PM2.5 concentrations and O3 mixing ratios by 1.4 μg/m3 and 1.9 ppb, respectively, within the Pearl River Delta (PRD), China, according to a new study by a team from Emory University and the International Council on Clean Transportation (ICCT).
This resulted in an estimated 466 and 346 excess premature acute deaths from PM2.5 and O3, respectively, according to the study. Premature mortality from chronic exposures was even more significant, with 2,085 and 852 premature deaths from ship-related PM2.5 and O3, respectively. The open-access paper is published in the AGU journal GeoHealth.
The team also projected ship emissions in 2030 with and without an ECA, using two possible land scenarios.
With an ECA, the researchers predicted 76% reductions in SO2 and 13% reductions in NOx from the shipping sector. Assuming constant land emissions from 2015 in 2030 (2030 Constant scenario), they found that an ECA could avoid 811 PM2.5-related and 108 O3-related deaths from chronic exposures.
Using a 2030 projected scenario for land emissions, they found that an ECA would avoid 1,194 PM2.5-related and 160 O3-related premature deaths in 2030.
In both scenarios, implementing an ECA resulted in 30% fewer PM2.5-related premature deaths and 10% fewer O3 -related premature deaths, illustrating the importance of reducing ship emissions.
China, as the world’s largest product exporter, has substantial air quality and health risks associated with ship emissions. China owns nearly 5,000 ocean going vessels (OGVs) with a total capacity of over 160 million tons and handled approximately one quarter of the world throughput in its container ports in 2015. The three biggest port clusters in China are the Pearl River Delta (PRD), the Yangtze River Delta (YRD) and the Bohai Sea Rim (BR). The PRD port cluster, located in southern China, handled roughly 39% of all exports from China in 2015. The PRD port cluster has 11 major ports and three of them, Shenzhen, Hong Kong and Guangzhou ports, are all ranked among the top ten largest container ports by TEU (Twenty-foot Equivalent Unit) volume in the 107 world. At the same time, over 58 million residents lived in the central PRD region in 2015 and two megacities, Guangzhou and Shenzhen, had over 13 and 11 million residents, respectively. Therefore, how the emissions from oceangoing ships might pollute the air and threaten the health of local residents is of particular importance.
… Our results show that ship emissions caused major environmental and health impacts in 2015 in PRD and will continue to do so in 2030. Implementing an ECA would improve air quality substantially and reduce premature mortality in the PRD region of China. We also found that an ECA is effective for PRD, regardless of land emissions.—Chen et al.
Chen Chen, Eri Saikawa, Bryan Comer, Xiaoli Mao, Dan Rutherford (2019) “Ship Emission Impacts on Air Quality and Human Health in the Pearl River Delta (PRD) Region, China in 2015, with Projections to 2030” GeoHealth doi: 10.1029/2019GH000183