Application of different risk assessment methods in occupational health risk assessment in sewage treatment industry

  Objective  The applicability of different risk assessment methods to occupational health risk assessment of key work places in sewage treatment industry was compared.

  Methods  The EPA method, GBZ/T 229 workplace occupational hazard classification method, GBZ/T 298 -2017 comprehensive index method, ICMM method and Australian method were used to assess the occupational health risk in 3 sewage treatment enterprises. The occupational health risk in the key workplaces where workers exposed to ammonia, hydrogen sulfide and dust were evaluated. The risk levels got by different methods were standardized and compared.

  Results  The exposure levels of NH₃, H₂S and dust in each workplace in 3 sewage treatment plants were lower than national exposure limits. EPA method showed that the occupational health risk of H₂S in each workplace was extremely high (level 5), and risk of NH₃ was medium (level 3). Both GBZ/T 229 job classification method and ICMM matrix method showed that the occupational health risks of NH₃, H₂S and dust were low (level 2). The ICMM showed that the occupational health risks of NH₃, H₂S and dust were negligible (level 1). GBZ/T 298-2017 comprehensive index method showed that the occupational health risks of NH₃ and H₂S were medium (level 3), and risk of dust was negligible (level 1). Australian method showed that the occupational health risk of NH₃ and H₂S was high (level 4), and the risk of dust was medium (level 3).

  Conclusions  The different risk assessment methods showed various results of occupational health risk in the sewage treatment industry. GBZ/T 298-2017 comprehensive index method combined with Australian method is more suitable for occupational health risk assessment in sewage treatment industry.