Occupational Health–Life Cycle Assessment (OH-LCA) of green waste management: A case study of Thailand's steel waste processing industry

Ensuring both worker safety and environmental sustainability remains a critical, often overlooked challenge within circular economy practices. While recycling reduces external environmental burdens, it frequently concentrates hazardous exposures within the workplace. This study developed a combined Occupational Health-Life Cycle Assessment (OH-LCA) framework to evaluate a formal steel coil recycling facility in Thailand. The methodology employed Industrial Hygiene (IH) Principles-specifically real-time Internet of Things (iOT) monitoring to independently validate the fine particulate matter formation impact modeled in the LCA. Importantly, Workplace Environment Characterization Factors (WE-CFs) were not applied; instead, the IoT exposure data served as empirical cross validation of the LCA's Human Health endpoint rather than direct inputs to the Life Cycle Inventory. Sequential operations were assessed using a semi-quantitative Hazard Identification and Risk Assessment (HIRA), while the IH “Evaluation” phase utilized IoT sensors to validate theoretical impacts modeled in OpenLCA using the ReCiPe 2016 Endpoint method. The “Cutting” stage was identified as the critical hotspot. Real-time sensors detected acute PM2.5 concentrations peaking at approximately 1398 μg/m 3 , empirically corroborating the high Human Health damage modeled in the LCA, which totaled 4.69 DALYs/month. The LCA further revealed a significant resource depletion cost of 11,368 USD/month. Eco-efficiency analysis demonstrated a critical trade-off: while the process was highly efficient for ecosystem preservation (25,871 ton/species·yr), it showed comparatively lower efficiency for human health protection and resource conservation. A techno-economic analysis further indicated that implementing IoT-based engineering controls is economically viable, offsetting initial investments through reduced energy consumption and mitigated long-term health liabilities. These findings highlight that formal ISO certifications alone do not guarantee worker safety during high-energy unit operations. The study concludes that integrating real-time IH monitoring with LCA provides a proactive, scalable pathway for decarbonizing the waste sector while ensuring worker well-being in the “Next Normal” industrial landscape. • Introduces a combined environmental LCA and occupational health assessment framework with IoT-based cross validation for steel coil recycling. • The cutting stage shows PM 2.5 levels (∼1398 μg/m 3 ), resulting in the health impacts (4.69 DALY). • Energy use and emissions were the main drivers of health damage and resource depletion, while impacts on ecosystems were relatively small. • IoT-based monitoring makes recycling both safer for workers and more sustainable.