Industrial Hygiene Essay

The Occupational Safety and Health Administration (OSHA), the National Institute for Occupational Safety and Health (NIOSH), the American Conference of Governmental Industrial Hygienists (ACGIH), and the American Industrial Hygiene Association (AIHA) are four major organizations with a great amount of influence on the industrial hygiene field. 
Prepare your essay comparing the missions of each of the four organizations and their influence on the practice of industrial hygiene. Choose one of the organizations, and describe how the passage of the OSH Act of 1970 influenced the foundation of the organization. What is the most significant contribution that your chosen organization has made to worker health and safety?