A study by the School of Engineering of the University of Minho, conducted by Pamela Sant’Anna, evaluated a sample of 54 municipal solid waste (MSW) collection workers from three municipalities in northern Portugal and concluded that 85% of them reported musculoskeletal pain in the last year, especially in the lower back (65%), shoulders (63%) and knees (50%). The research focused on analysing the process of manual door-to-door collection of MSW or MSW deposited in mobile containers.

The researcher also found that 18% of respondents experienced cardiovascular overload while performing the set of tasks associated with manual MSW collection. Tests conducted under controlled experimental conditions, using ten volunteers (students and professionals) from UMinho, also revealed that lifting, carrying and throwing bags or pushing containers resulted in high postural risk.

‘Mechanised collection using four-wheeled containers and teams of two people is recommended as the safest alternative to reduce physical effort and prevent injuries,’ says Pamela Sant’Anna, who conducted the research at the Algoritmi Centre as part of her PhD thesis in Industrial and Systems Engineering. The study was supervised by professors Nélson Costa and Pedro Arezes, from the School of Engineering at UMinho, and Eliane Lago, from the Polytechnic School of the University of Pernambuco (Brazil).

‘It is urgent to rethink MSW collection methods because they directly influence the health of these professionals, who play an essential but still invisible role in cities,’ the author emphasises. Her research also aims to contribute to the formulation of public policies on occupational health and waste management, promoting better working conditions and greater sustainability in the sector.