Simon was a physician by training, but he is most famous for his dramatic reforms of London's public health system, which set the standard for 19th-century urban sanitation and health measures. Of the era's public health advocates, Simon is generally regarded as one of the most influential.

Born in London, Simon received his early medical education during his work as an apprentice to a well-known local surgeon at the St. Thomas Hospital. He completed his formal studies at the University of London's King's College, and from 1840 to 1847 served as a surgeon at the school's associated hospital.

Simon became the City of London's first medical officer of health in 1848, and in that capacity issued annual reports that led directly to the Sanitary Act of 1866. This landmark legislation formed the backdrop for industrial hygiene policy and created the first mandatory, universal, and science-based public health law. Simon's involvement here helped...