Ergonomic risk assessment in municipal waste management: integrating standardized methods with real-world context.

Introduction: Manual handling of loads (MHL) represents a relevant occupational risk in the waste management sector, where lifting, pushing, and pulling are performed daily under variable and often complex operational conditions. This study aimed to assess ergonomic risk in a municipal waste management company through the application of standardized methods and to evaluate their utility for preventive decision-making in real-world contexts. Methods: This field-based ergonomic case study was conducted in a municipal waste management company. Ergonomic assessment worksheets were used to characterize two homogeneous door-to-door waste collection task scenarios: domestic collection and commercial collection. For lifting, worksheet-derived task duration, number of lifted objects, lifting frequency, load distribution, frequency/duration multipliers, and Lifting Index values were extracted and reported. Lifting indices were calculated according to the ISO 11228-1/ISO/TR 12295 framework using population-specific reference masses by sex and age group. Transport and towing components were assessed through worksheet-based indices derived from measured and recommended forces. Results: In the domestic collection scenario, two workers were involved: manual lifting lasted 180 min, with 182.5 objects lifted per worker and a lifting frequency of 1.014 lifts/min. Load distribution was mainly concentrated in the 5.5 kg category (82.2%), followed by 9.5 kg (16.4%) and 13.5 kg (1.4%). Lifting indices ranged from 0.746 in men aged 18-45 years to 1.243 in women aged >45 years. In the commercial collection scenario, one worker was involved: manual lifting lasted 120 min, with 60 objects lifted per worker, all in the 9.5 kg category, and a lifting frequency of 0.5 lifts/min. Lifting indices ranged from 0.442 in men aged 18-45 years to 0.737 in women aged >45 years. Towing indices remained below unity in both scenarios, with higher values for women during the maintenance phase. Discussion: Although most ergonomic indices remained within acceptable limits, the domestic collection scenario showed a subgroup-specific exceedance for women aged >45 years. Conclusion: Standardized ergonomic tools are useful for preventive planning in municipal waste management, provided that their results are interpreted in relation to actual task duration, load distribution, worker fitness for the task, and environmental variability. The findings support targeted preventive measures.