In this role, Howard advocated for rescue workers, introducing a program to provide screening, medical exams, and treatment for them.

[6] Howard began his career in occupational health in 1979 as an internist at the UCLA School of Medicine pulmonary fellowship program at Cedars-Sinai Medical Center.

His clinical work involved asbestos-exposed shipyard workers, and he published research findings related to workplace exposure and occupational lung disease.

[9] Howard served as the chief of the Division of Occupational Safety and Health in California's Department of Industrial Relations from 1991 to 2002.

The position was not filled until July 15, 2002, when Tommy Thompson, Health and Human Services Secretary placed John Howard in the post.

This included an initiative called "research-to-practice" (r2p) to ensure that NIOSH's findings would turn into practices and products that would ultimately benefit workers.

[12] John Howard was appointed by President George W. Bush to be a special coordinator to handle the medical issues afflicting 9/11 rescue workers, specifically those at the World Trade Center site.

[10] As Howard's 6-year term approached its close, Centers for Disease Control and Prevention (CDC) director Julie Gerberding met with him to inform him that he would not be reappointed.