Integrated assessment of inhalation health risk and economic benefit of improving ambient targeted VOCs in Petrochemical industrial area

The Maptaphut industrial area, one of the largest petrochemical complexes in Thailand, is the major cause of the various air pollutants. The larger concern is that a significant volume of air pollution is emitted and that air quality management needs to be improved. This is in part due to a lack of deeper understanding of how anthropogenic emissions are emitted from different sources in this area— especially volatile organic compounds (VOCs). Moreover, it has complicated relationship results of air pollution, disease mechanisms, and health effects. As a result, its available data can only give a rough indication of them. These factors are often assumed to be associated with economic consequences, but assessing the health-related economic losses caused by air pollution remains limited in many ways.

Four targeted VOCs were analyzed, including benzene, 1,3-butadiene, 1,2-dichloroethane, and vinyl chloride from industrial and non-industrial sources, namely stacks, flares, storage tanks, wastewater treatment plants, transportation and marketing, fugitive losses, slurry/open equipment/vessel, and on-road mobile emissions. Source apportionment can be conducted using emissions inventory (EI) to establish pollution source databases, the dispersion model, and then imported on the risk model by determining receptors. The AERMOD dispersion model coupled with the IRAP-h view model was used to predict the spatial distribution of the ground-level concentration and analyze the inhalation health risk covering cancer and non-cancer risks— as well as the prioritization of pollutants.

The risk assessment results indicated that the highest risk occurred most from 1,3-butadiene for cancer and chronic non-cancer risks contributed to fugitive sources, about 83% and 94%, and most benzenes for acute non-cancer risk contributed to on-road mobile sources, at about 56%.

Consequently, the benzene classified as the most important priority depending on its risk results, comprehensive epidemiological studies, and discharge volumes.

With the economic benefits assessment, BenMAP-CE was further utilized to estimate the health impacts and economic value of multiple scenarios to facilitate decision-making for benzene reduction. Overall, the 10% rollback policy for benzene concentration, monetized value of about 13.13 billion US dollars for all mortalities, gave the best practical scenario for the most economically viable option based on the B/C (benefit/cost) ratio results in Maptaphut. Ultimately, policymakers need to take additional measures to improve air quality and reduce health impacts while also considering economic benefits, especially benzene reduction.