It is no exaggeration to state that in the majority of theater buildings disgracefully unsanitary conditions prevail. In the older existing buildings especially sanitation and ventilation are sadly neglected. The air of many theaters during a performance becomes overheated and stuffy, pre-eminently so in the case of theaters where illumination is effected by means of gaslights. At the end of a long performance the air is often almost unbearably foul, causing headache, nausea, and dizziness.
In ill-ventilated theaters a chilly air often blows into the auditorium from the stage when the curtain is raised. This air movement is the cause of colds to many persons in the audience, and it is otherwise objectionable, for it carries with it noxious odors from the stage or under stage, and in gas-lighted theaters this air is laden with products of combustion from the footlights and other means of stage illumination.
Attempts at ventilation are made by utilizing the heat due to the numerous flames of the central chandelier over the auditorium, to create an ascending draught, and thereby cause a removal of the contaminated air, but seldom is provision made for the introduction of fresh air from outdoors, hence the scheme of ventilation results in failure. In other buildings, openings for the introduction of pure air are provided under the seats or in the floor, but are often found stuffed up with paper because the audience suffered from draughts. The fear of draughts in a theater also leads to the closing of the few possibly available outside windows and doors. The plan of a theater building renders it almost impossible to provide outside windows, therefore "air flushing" during the day can not be practiced. In the case of the older theaters, which are located in the midst or rear of other buildings, the nature of the site precludes a good arrangement of the main fresh-air ducts for the auditorium.
Absence of fresh air is not the only sanitary defect of theater buildings; there are many other defects and sources of air pollution. In the parts devoted to the audience, the carpeted floors become saturated with dirt and dust carried in by the playgoers, and with expectorations from careless or untidy persons which in a mixed theater audience are ever present. The dust likewise adheres to furniture, plush seats, hangings, and decorations, and intermingled with it are numerous minute floating organisms, and doubtless some germs of disease.