Occupational health concerns related to cannabis use means that when someone uses cannabis, it may affect the health and safety of their job. Some workers may have jobs where they work with dangerous machinery, use hazardous materials, or operate vehicles. Using cannabis can make it harder to focus and be alert, which could put them or others at risk of an accident. In some jobs, using cannabis can also make it more difficult to make good decisions or follow instructions, which can impact the quality of their work.