Development of a system dynamics model for polycyclic aromatic hydrocarbons and its application to assess the benefits of pollution reduction.

A dynamic multimedia transport (DMT) model for polycyclic aromatic hydrocarbons (PAHs) was constructed using the system dynamics software STELLA to simulate the transmission and flow of PAHs in different media. Humans are primarily exposed to PAHs via ingestion. Thus, this study used the DMT model to simulate the concentrations of PAHs in food media and the human body and assess the risk of harm to humans. On the basis of the hypothesis of PAH reduction in the Taiwanese steel industry, two scenarios were used (cases I and II), and integration indicators such as the Air Resource Co-Benefit Model of air pollutants, greenhouse gases, and PAHs reduction was established for the cost-benefit analysis of the reduction scenarios. This study not only established Taiwan's PAHs dynamic multimedia transmission model successfully but also performed a reduction scenario on the steel industry. In the year 2025, the total costs for cases I and II will be USD 690 and USD 694 million per year, respectively, and the total benefits will be USD 492 and 1669 million per year, respectively. Therefore, case II is preferable to case I in terms of benefit ratio (2.40 vs. 2.35, respectively).