This type of occupational health preventative approach can enable you, as an employer, to be made aware of health problems early on; thus allowing timely intervention to prevent problems being caused or made worse by work activities. For example Physical Hazards i.e. exposure to radiation, heat and cold. Biological Hazards i.e. Blood Borne Infections, Salmonella. Another important role of health monitoring is to ensure the health, safety and well-being of staff by providing preventative measures; for example drug and alcohol testing to detect those employees with alcohol and substance misuse problems.