 The first study that was done by Consultech Engineering, Co. under contract to Actor's Equity.The findings of the Consultech study were confirmed by two additional studies—a Health Hazard Evaluation completed in 1994 by the National Institute for Occupational Safety and Health, and another one in 2000 by the Department of Community and Preventative Medicine at the Mount Sinai School of Medicine and ENVIRON; both prepared for Actors Equity and the League of American Theatres and Producers, focused on the effects on actors and performers in Broadway musicals.The conclusion of all three studies was that there was irritation of mucous membranes such as the eyes and the respiratory tract associated with extended peak exposure to theatrical fog.