Primary Particulate Matter Emitted from Heavy Fuel and Diesel Oil Combustion in a Typical Container Ship: Characteristics and Toxicity

Container ships have been widely recognized as an important emission source within maritime transport. Heavy fuel oil (HFO) and diesel oil (DO) are the two most commonly used fuels. This study reports the characteristics and toxicities of particulate matter (PM) emissions from HFO and DO combustion in a typical container ship. The PM number size distribution possesses a bimodal structure with peaks at similar to 20 nm and similar to 100 nm. The PM 2.5 emission factors (EFs) are 3.15 +/- 0.39 and 0.92 +/- 0.02 g/kg fuel for HFO and DO, respectively. The benzo[a]pyrene equivalent carcinogenic potency (BaPeq ) of 16 polycyclic aromatic hydrocarbons contained in HFO and DO PM 2.5 is approximately 0.81 +/- 0.10 and 0.12 +/- 0.04 mg/kg fuel, respectively. BaPeq concentration shows an increasing tendency with decreased PM size. The reactive oxygen species activity and cytotoxicity of HFO PM2.5 samples are similar to 2.1 and similar to 2.5 times higher than those of DO PM2.5 samples, respectively. These health risks are both significantly attributed to the BaP eq content in PM2.5 with correlations of 0.86-0.92. Furthermore, the examined biological effects are much greater than those of atmospheric PM2.5 collected in Shanghai. Our results imply that better fuel quality is important for improving air quality and reducing health risks.