In accordance with the requirements of the \"Administrative Measures for Occupational Health Surveillance\" issued by the Ministry of Health, the contents of occupational health examinations include: general demographic information of workers exposed to hazards, history of occupational exposure, frequency of physical examinations, examination items before starting work and during employment, as well as occupational contraindications. I. Occupational health examination items: The examination items include general examination items, special examination items, and optional examination items. The selection of items for inspection should be determined based on the instrumentation and equipment available in medical and health institutions, as well as the level of occupational disease hazards in the workplace and the extent of health damage to workers. (i) Generally, when conducting occupational health examinations, attention should be paid to factors such as the duration of time the individual has been engaged in work involving occupational disease hazards, past medical history, personal lifestyle, family history, history of infectious diseases, and drug allergies. Obtaining this information is of great importance for understanding the individual’s physical condition, lifestyle habits, and individual differences, as well as for assessing the impact of occupational disease hazards. (ii) Investigation of occupational exposure history: The occupational history of workers exposed to occupational disease hazards is the most significant feature of occupational health examinations, and it also serves as an important basis for the diagnosis of various occupational diseases. It includes the time, location, employer, type of work, position, method of work, and any changes related to the subject’s exposure to hazardous tasks. It also covers the concentration (intensity) of harmful substances in the workplace as well as the protective measures in place; this information must be provided by the workers who are exposed to hazardous tasks or by their employers. (III) Physical examination items: The occupational health examination items shall comply with the provisions regarding pre-employment and on-the-job examinations set out in the Ministry of Health’s \"Administrative Measures for Occupational Health Surveillance\". If the employer has special requirements, additional inspection items can be agreed upon through negotiation. II. Period for occupational health examinations: The interval between occupational health examinations, that is, the period between such checks, should comply with the regulations regarding the frequency of examinations during employment set out in the Ministry of Health’s \"Administrative Measures for Occupational Health Monitoring.\" However, given the wide variety of occupational hazards in the production environment, there are many harmful factors that are not covered by the provisions of the \"Regulations on Occupational Health Surveillance.\" For such hazards, employers should determine the frequency of health checks based on the results of environmental monitoring and the health status of the workers. ①Among the toxic substances, except for sulfur dioxide and carbonyl nickel, which are tested once every 2 years ; Other toxic substances are once a year. ②Silica dust and asbestos dust in inorganic dusts – once a year ; Coal dust, carbon black dust, graphite dust, talc dust, mica dust, cement dust, clay dust, foundry dust, aluminum dust, welding dust – once every 2 years ; Other dusts: once every 3-5 years ; Organic dust once every 3-5 years. ③High temperatures, noise, high air pressure, local vibrations, ultraviolet rays (electro-optic keratopathy), external radiation, internal radiation, biological factors (Bacillus anthracis, Forest Virus, Brucella), chemicals that can cause bursitis in coal miners as well as occupational skin diseases; chemicals that cause chemical eye burns; physicochemical factors (occupational cataracts); chromium and its compounds (chromic nasal disease); substances that cause asthma; acids and acid derivatives that cause tooth erosion. Testing is required once a year for motor vehicle driving tasks.④ Microwaves, video work, electrical work, and work at heights require testing every 2 years. ⑤Pressure vessel operations are carried out once every 3 years. ⑥Bladder cancer caused by aniline, 6 years after exposure ; Aniline >5% once a year