New concept for occupational health development: 3 phases.

Occupational health development in a country can be classified into 3 phases as External, Internal (or Personal), and Social Environmental Phases. Occupational health usually focuses on work environment, but it cannot advance without controlling workers' health and cannot be achieved without a complimentary understanding of the social security system. Society may continue wasting social costs for determining whether a disease of workers is caused by or arising from work. In order to understand the status of occupational diseases in a country, one must know about the comprehensiveness of the social security system in that society.