The UMass Lowell Department of Public Health offers a doctoral program that focuses on occupational and environmental hygiene, ergonomics and safety, epidemiology, work environment policy and cleaner production, pollution prevention. Doctoral training is built upon the substantial didactic training gained in the master's degree programs. To be eligible for admission to a doctoral program, an applicant will need to demonstrate appropriate undergraduate education with adequate preparation in quantitative sciences and a master's degree in work environment or a related field. He or she will need to provide a minimum of three letters of reference attesting to the ability to perform advanced graduate work and to provide a written statement of career objectives and the relationship of doctoral training to those objectives.