1, chemical factors in raw materials, intermediate products and finished products, and active factors that can endanger health, such as waste gas, waste water and waste residue. Where a small amount of substances harmful to human body are ingested, they are called poisons. Poisons are scattered in the air in the form of dust, smoke, fog, steam or gas.
2. Biological factors, pathogenic microorganisms or parasites existing in raw materials and working environment, such as Bacillus anthracis, fungal spores, Brucella, forest encephalitis virus, mold on bagasse, etc. Infectious pathogens that medical personnel are exposed to, such as SARS virus.
3. Social and economic factors such as economic globalization, gross national product, wealth distribution, education level, ecological environment, labor legislation and medical and health system will all affect the health of occupational population. Such as low level of production management, poor plant or equipment, excessive physical load, unreasonable production layout, etc.