As part of Xerox's ongoing commitment to their employees and customers, the company has sponsored a set of large, complex health studies. The Xerox 'Health Studies' have been underway since 1982 and include both studies of animals exposed to very high concentrations of specially prepared toner as well as studies of toner-exposed employees. These worker studies include an 'Employee Health Study' (a study which consists of results from lung function tests and a health questionnaire on Xerox manufacturing workers and Service Engineers), and a 'Mortality Study'(a study that was done to see if there were any trends in the causes of death of Xerox employees indicative of possible risks from toner). The studies complement one another in terms of offering evidence of any hazards associated with exposure to toner. The most recent findings of the 'Mortality Study' were reviewed in a separate report. This monograph summarizes the data from the 'Employee Health Study'. The program included voluntary participants in Monroe County, New York (2225 people), Oklahoma City, Oklahoma (329 people), Venray, Holland (905 people) and U.S. customer service engineers (4157 people). The protocol included standardized questions on respiratory symptoms and diseases and spirometry, a test of lung function. The design of the study is cross-sectional, that is on health status of the workers at a particular point in time. The focus is on the potential effect of toner on the lungs.