Investigation and Health Risk Assessment of Volatile Organic Compounds (VOCs) Emitted from Industrial Estate, Rayong City, Thailand in 2024

Volatile organic compounds (VOCs) in ambient air remain a public health concern due to their potential short and long-term health effects. This study aimed to measure VOC concentrations and assess related health risks in the industrial estate of Rayong city, Thailand. Daily VOC levels were continuously monitored at three Air Quality Monitoring stations in Maptaphut City Municipality from January to December 2024. Mean concentrations of vinyl chloride, benzene, and ethylbenzene varied significantly across the monitoring sites (P < 0.05), while total VOC levels did not differ between the dry and wet seasons (P > 0.05). Meteorological factors, particularly air temperature and relative humidity, appeared to influence VOC levels. Notably, ambient concentrations of 1,3-butadiene (1.13 ± 1.06 to 1.49 ± 1.91 µg/m³) exceeded the annual standard of 0.33 µg/m³ set by the Pollution Control Department. Principal component analysis (PCA) identified several emission sources, including synthetic rubber and thermoplastic resin production, wastewater treatment, vehicle exhaust, industrial solvent use, and emissions from PVC-related processes. Carcinogenic equivalency (CEQ) values were highest near petrochemical facilities producing plastic resins or polymers and areas linked to wastewater treatment, reflecting the presence of carcinogenic VOCs. Despite elevated levels of 1,3-butadiene, both carcinogenic and non-carcinogenic risk assessments suggested no immediate adverse health effects for the surrounding population. However, the findings highlight the need for continued monitoring, particularly due to the long-term cancer risk associated with 1,3-butadiene.