ABSTRACT THE EFFECT OF USING MASK ON CHANGES OF RESIDENT FLORA ON HOSPITAL HEALTH WORKERS’ FACIAL SKIN IN PEKANBARU By Adrian Hartanto COVID-19 is an infectious disease caused by SARS-CoV-2. One of the preventions of this disease is the use of masks which must be used by health workers. The use of mask can affect several skin characteristics. The Skin has resident flora which is located o…