Radiography involves the use of ionising radiation. The radiation generated by radiography equipment is invisible and not directly detectable by human senses. Instruments are usually required to detect its presence. Ionizing radiation is widely used in industry and medicine, but presents a significant health hazard. It causes microscopic damage to living tissue, resulting in skin burns and radiation sickness at high exposures and statistically elevated risks of cancer, tumours and genetic damage at low exposures. Regulations require employers to ensure that their employees and others are not exposed to health risks as a result of their use of ionising radiations. Compliance will require the assistance of a certificated radiological protection advisor (RPA) to advise the employer on the local rules that will be required if they are to meet the specific requirements. Employers will also need to appoint competent Radiation Protection Supervisors (RPS) with sufficient management responsibility to ensure that the local radiation protection arrangements are properly implemented and managed. See also: Radiation.