Abstract: This paper was aimed at making up for China' lack of research on the NaTech disasters caused by natural disasters, especially the lack of quantitative assessment of the safety and health risks to the public resulting from the release and wide spread of toxic and hazardous chemicals associated with such accidents. Taking the damage and leakage of PX storage tanks under earthquake in a coastal chemical industry park in China as the case study, the process of PX leakage and diffusion was simulated according to the disaster chain method, and the resulting public safety and health risks were evaluated quantitatively. The results show that the mass concentration of PX diffusion has certain spatial distribution characteristics and is dependent on the seasons and time when earthquakes often occur, and that TIBL should be considered in the risk assessment of Natech in coastal areas, in order not to underestimate the risk.

Key words: NaTech, earthquake, para-xylene(PX), quantitative risk assessment, meteorological scenario, thermal internal boundary layer (TIBL)