Health risk assessment of benzene, toluene, ethylbenzene, and xylene among occupational and residential populations at landfill, Indonesia

Abstract

Personal monitoring of benzene, toluene, ethylbenzene and xylene (BTEX) exposure at municipal solid waste landfills remains scarce in Indonesia, despite its importance for capturing individual exposure variability and improving health risk assessment. This study evaluated inhalation health risks associated with personal BTEX exposure among occupational and residential populations living around an open dumping landfill. Personal air samples were collected from 56 participants, including scavengers, landfill workers, nearby residents and controls group. Personal monitoring was conducted using personal air sampling pumps at 0.045–0.2 L min −1 , following NIOSH 1501 Method. BTEX concentrations were analyzed using GC-FID. Benzene was the dominant contributor to non-carcinogenic risk across all exposed groups. Scavengers exhibited the highest non-carcinogenic risk, with a mean Hazard Index (HI) of 3.73 ± 2.36 ( p  < 0.05). Although the average HI among landfill workers and nearby residents remained below the safety threshold, maximum values reached 3.72 and 1.54, respectively, indicating that some individuals exceeded the acceptable non-carcinogenic risk threshold (HI > 1). Benzene-related carcinogenic risk was also highest among scavengers (4.05 × 10 −5 – 1.50 × 10 −4 ). Compared with controls, both non-carcinogenic and carcinogenic risks were 13 times higher among scavengers and four times higher among landfill workers and nearby residents. These findings show open dumping landfills are significant sources of benzene exposure and associated inhalation health risks. They also highlight the urgent need for targeted interventions prioritizing scavengers, strengthened occupational protection and sustainable waste management strategies to reduce health risks among occupational and nearby communities.