Increased exposure to nanoscale particles (NPs) in living and occupational environments has produced various harmful effects in recent years. Owing to their small particle size and physicochemical properties, NPs can evade engineered defenses, exhibit greater toxicity, and affect the physiological functions of multiple organs in the human body through the circulatory system and biological barriers. Therefore, we should pay attention to the multi-organ toxicity effects caused by NPs and their mechanisms. High-level occupational exposure to NPs at elevated concentrations constitutes a substantial threat to the health of workers. Therefore, it is necessary to conduct a targeted assessment of the health risks of NPs in the occupational environment. This paper provides a comprehensive review of the sources of NPs in both living and occupational environments. Specifically, it highlights the disparities in the characteristics and associated toxicities between nanoscale and microscale inhalable particulate matter within the occupational context. Moreover, it delves deeply into the contributions of NPs to multi-organ toxicity effects and the underlying pathological mechanisms.