Toxic contaminants in wastewater from the stone-cutting industry: Monitoring and occupational risk via accidental ingestion

Abstract

Workers in the stone-cutting industry are exposed to hazardous pollutants originating from adhesives, lubricants, resins, and surface coatings used during polishing, which enter wastewater through high-pressure rinsing. While inhalation and dermal contact have been widely studied, accidental ingestion of contaminated water remains an overlooked pathway in occupational health. In this study, eight priority pollutants were quantified in polishing wastewater using DLLME followed by GC/MS. These contaminants included Bisphenol A (BPA) and Methylphenol (MP) as phenolic compounds; Pentachlorobiphenyl (PCB), Tetrachlorobiphenyl (TCB), and Dichlorobiphenyl (DCB) as polychlorinated biphenyls (PCBs); and Naphthol (Nap), Phenanthrene (Ph), and Chrysene (Chy) as polycyclic aromatic hydrocarbons (PAHs). Human health risks were assessed through Monte Carlo simulations and sensitivity analysis. Results showed that several pollutants exceeded the non-carcinogenic safety threshold (HQ > 1), and the cumulative Hazard Index (HI) was far greater than 1. The total cancer risk (TCR) also surpassed the acceptable limit (1 x 10(-)(4)). These findings highlight ingestion as a critical but neglected exposure route that should be explicitly integrated into occupational risk assessments.