Landrigan's reputation rests largely on his role as a highly credible evidence-based advocate for public health, specifically in his focus on reducing the level of children's exposure to lead and pesticides and for his participation in the World Health Organization's global campaign to eradicate smallpox. He was also a central figure in developing the National Children's Study and in the medical and epidemiological studies that followed the destruction of the World Trade Center on September 11, 2001. Additionally, from 1995 to 1997, Landrigan served on the Presidential Advisory Committee on Gulf War Veteran's Illnesses, and, in 1997 and 1998, served as Senior Advisor on Children's Health to the Administrator of the U.S. Environmental Protection Agency, where he helped establish the Office of Children's Health Protection.