Behind the waste: a systematic review of leading causes contributing to occupational health and safety issues among municipal solid waste handlers

Abstract

Municipal solid waste (MSW) handlers are among the most vulnerable occupational groups, frequently operating in hazardous environments with limited protective measures. Despite increasing awareness of these risks, scientific studies investigating the root causes of occupational health and safety (OHS) issues among MSW handlers remain limited and, in many cases, outdated. A comprehensive synthesis is therefore essential to deepen our understanding of the multifaceted causes contributing to unsafe working conditions in this sector. This study aims to address this gap by systematically synthesising the existing literature on the causes of OHS issues faced by MSW handlers. To achieve this aim, the study is guided by the three objectives: 1) review the overview of the OHS of MSW handlers, 2) review the rea-sons behind the OHS issues of MSW handlers and 3) explore the next line of research in OHS of MSW handlers. A total of 117 peer-reviewed articles published between 1995 and March 2025 were selected from the Web of Science (WoS) database and analysed using a combination of descriptive and content analysis. The descriptive findings indicate a predominant publication contribution on developing and emerging economies, where OHS issues among waste handlers are particularly acute. The content analysis revealed that the causes of OHS risks can be broadly grouped into three thematic categories: organisational factors (e.g., lack of training, absence of safety protocols, and inadequate provision of personal protective equipment), individual factors (e.g., low awareness of occupational hazards, informal employment, and limited education), and physical factors (e.g., exposure to hazardous waste, extreme weather, and unsanitary work environments).This study makes a significant contribution by not only identifying these core causes but also proposing a structured set of strategies to mitigate OHS risks. It further identifies emerging trends and gaps in the literature, suggesting that future research should focus on context-rich, empirical case studies to evaluate the practical effectiveness of existing and proposed OHS interventions. Key directions for future research include the development of integrated approaches to OHS risk assessment in MSW handling, the enhancement of OHS standards in informal waste sectors, and policy evaluation and implementation studies to assess the impact of regulatory measures. Through this comprehensive synthesis, the study contributes meaningfully to the literature and provides a foundation for policymaking, practice, and academic inquiry aimed at safeguarding the health and dignity of MSW handlers.