从2020年1月1日起,国际海事组织(IMO)关于燃油含硫量限制为0.5%的规定生效,船舶通常安装硫磺洗涤器或使用低硫燃料或液化天然气代替富含硫的重质燃料油。在这项研究中,北九州沿海郊区的4年PM2.5采样,日本明确指出了相关法规和对策对该受体位点的颗粒发射的显着影响。从空气质量的角度来看,2020年船舶排放颗粒的质量浓度明显下降,硫酸盐的贡献可达60%。铵浓度主要由硫酸盐和硝酸盐控制,它的减少也不容忽视,约占17%。在公共卫生方面,颗粒暴露风险也发生了很大变化,主要是由于As的风险水平降低,W,Sb,V,Ni,和Cd;成人(HI=1.2,CR=5.7×10-5)和儿童(HI=9.9,CR=1.1×10-4)的非致癌风险和致癌风险均在2020年发生。然而,这些降低的健康风险仍然不在安全水平内(成人的致癌风险除外),一个需要持续关注的事实。这一结果暴露了北九州市国际海事组织燃料硫含量限值目前对策的不足,并增加使用清洁燃料(液化天然气,甲醇,等。)肯定会减轻船舶排放造成的颗粒物污染。
From January 1, 2020, the International Maritime Organization (IMO) regulation about the limit of fuel sulfur content to 0.5 % become effective, and ships commonly install sulfur scrubbers or use low-sulfur fuel or liquefied natural gas to replace sulfur-rich heavy fuel oil. In this study, the 4-year PM2.5 sampling in the coastal suburbs of Kitakyushu, Japan clearly indicated the significant effects of relevant regulation and countermeasures on particle emissions in this receptor site. From the perspective of air quality, an obvious decrease in the mass concentration of ship-emitted particles was observed in 2020, and the contribution of
sulfate could reach 60 %. The ammonium concentration was mainly controlled by
sulfate and nitrate, and its reduction also could not be ignored, accounting for about 17 %. In terms of public health, the particle exposure risk also changed greatly, mainly due to the reduction of risk levels for As, W, Sb, V, Ni, and Cd; the lowest non-carcinogenic risk and carcinogenic risk for both adults (HI = 1.2 and CR = 5.7 × 10-5) and children (HI = 9.9 and CR = 1.1 × 10-4) all occurred in 2020. However, these reduced health risks were still not within the safe level (except for the carcinogenic risk for adults), a fact that requires continued attention. This result exposed the deficiency of current countermeasures regarding the IMO\'s fuel sulfur content limit in Kitakyushu City, and increasing the proportion of ships using clean fuels (liquefied natural gas, methanol, etc.) would surely alleviate the particle pollution caused by ship emissions.