Unmasking the aromatic production Industry's VOCs: Unraveling environmental and health impacts

In this study, we conducted a thorough investigation into the critical volatile organic compounds (VOCs), namely benzene, toluene, and xylenes (BTX), originating from the aromatic production industry. Our primary goal was to assess their spatial dispersion and source contribution, providing a comprehensive evaluation of their environmental and health impacts. The aromatic plant's average annual benzene concentrations were found to be compliant with Thailand's standard. However, xylenes did not meet the mandatory standards and emerged as the dominant species in the surrounding vicinity, with both maximum hourly and average annual concentrations exceeding the limits. Emission rate, meteorological characteristics, and topographical levels were identified as key factors affecting pollutant dispersion. The study utilized the maximum incremental reactivity (MIR) method to evaluate environmental risk assessment by calculating the ozone formation potential (OFP) of BTX. The total OFPs in the environment contributed by the aromatic plant ranged from 2.64 to 18.75 μg/m³. Xylenes emerged as the primary contributor to OFP concentrations at all receptor sites, accounting for 93–95% of the total OFP due to its high concentration and reactivity, followed by benzene and toluene. Storage tanks and wastewater treatment systems were identified as the main sources of ozone formation for benzene, toluene, and xylenes. Health risk assessment indicates an acceptable chronic hazard quotient (HQ) for each target organ system. For cancer risk, benzene slightly exceeds 10–6 at all receptors, necessitating consideration of pollutant concentrations, exposure duration, and other factors. The study emphasizes the importance of a comprehensive ambient monitoring network and updated emission inventory for effective air pollution management for the petrochemical enterprise, particularly in industrial areas.