In the 21st century climate of preventive medicine, we count on government agencies around the world to warn us about medical hazards in our lives. Yet, few people know that American national safety standards were pioneered by a 19th century female scientist, a pathologist who disliked conflict but used her fastidious research to challenge U.S. manufacturers on the issues of lead, explosives, coal and noxious dyes. Indeed, the Occupational Health and Safety Administration (OSHA) hails Alice Hamilton (1869–1970) as the founder of industrial medicine in America.

Born into a genteel family, Hamilton grew up in Fort Wayne, Indiana. Following her 1893 graduation from the University of Michigan-Ann Arbor’s medical program (she was one of only 14 women in a class of 47), Hamilton pursued a residency that took her into Boston’s slums and brothels. She followed this up with a year of study in Germany—which she relished even though she remembered being asked to make herself “invisible” and was told that a degree was “out of the question.” Returning to the U.S. in 1896, Hamilton continued her studies at the Johns Hopkins medical school for a year before receiving her first job offer as an instructor at Northwestern University’s Woman’s Medical School.

Moving to Chicago to work at Northwestern meant that Hamilton could follow another long-cherished hope she’d flirted with since 1889 when she saw progressive Jane Addams speak about settlement communities, places designed to serve as mutually beneficial bridges between the well-to-do and the poor.

You might say Hamilton got fully “woke” when Addams made a place for her in Chicago’s Hull House, the largest of the nation’s settlement communities. Hamilton was at first overwhelmed both by the intensity of the work and by the famous social reformers with whom she shared Hull House’s dinner table: Frances Perkins, Florence Kelly, Margaret Sanger, John Dewey, Eugene Debs and Upton Sinclair. But soon Hamilton was staffing a “well-baby clinic” for Hull House’s poor, immigrant women; and fresh from her studies at Johns Hopkins with famed pathologist Simon Flexner, she observed odd symptoms such as “wrist drop,” lead palsy and a large number of widows at the clinic.

Beginning in 1902, while living at Hull House, Hamilton also began schooling herself about lead and mercury poisoning as she got to know laborers and their wives. Supporting settlement family workers’ campaigns for the eight-hour day, Hamilton got a close-up view of the conditions of workers whose lives and families were often devastated by dangerous work environments.

In her autobiography, Exploring the Dangerous Trades (Atlantic Monthly Press, 1943), Hamilton described two of her key moments of awakening to the level of industrial lawlessness. One was her disturbing encounter with a Hungarian woman whose husband had been badly injured in a nearby steel mill and was being held “incommunicado” at a hospital. His terrified wife had no access to any information except that he was still alive. Only a formal prod from the Austro-Hungarian consul to the State Department prompted the release of information to his family.

Hamilton’s second wake-up call occurred when she encountered a works manager of a big white-lead plant. She described him as a “gentleman of breeding and something of a philanthropist,” who had spat back at her “indignantly” when she suggested that he would be responsible for employees at his plant who experienced lead poisoning.

“It was not that the employers were brutal,” she wrote. “They really did not know what was happening in their plants, for there was no system of workmen’s compensation to open their eyes to the hazards and to force safety measures.” Couched in such gentle language Hamilton’s tone was perhaps a nod to industrialists whom she had hoped to convince to do right by their employees.

“I do feel pretty much lost for it’s starting out into a great unknown and nobody seems to know the first step,” wrote the 41-year-old when she accepted the position of medical investigator for the Illinois Commission on Occupational Diseases in 1910. This new post and funding, a result of Hamilton’s growing reputation, connections at the Hull House and advocacy work, gave Hamilton nine months to draw a direct line between "disease and occupation." Managing a team of 23 physicians, students and social workers she investigated the hazards of exposure to lead.

“When I talked to my medical friends about the strange silence on this subject [lead poisoning] in American medical magazines and textbooks, I gained the impression that here was a subject tainted with Socialism or with feminine sentimentality for the poor.”

To accomplish real change, the team needed to document specific lead poisoning cases. They tracked down hospital records, met with physicians and pharmacists in working class quarters as well as labor leaders, visiting some 304 business establishments. Within a year, the team uncovered 70 different occupational processes that exposed workers to lead poisoning. Some unexpected cases included workers exposed to “freight car seals; coffin ‘trim’; decalcomania papers for pottery decoration; polishing cut glass; brass founding; wrapping cigars in so-called tinfoil, which is really lead.”

Hamilton’s Illinois study brought breakthroughs not yet documented in European literature. She discovered a sanitary-ware factory worker who exhibited symptoms of lead poisoning in an industry where they claimed he’d have no exposure. After meeting with the worker, she realized that she had not fully understood the enamel coating process. The work required sprinkling fine dust over a red-hot tub. A specimen revealed the existence of 20 percent soluble lead.

The Illinois survey, which included reports on arsenic, brass manufacturing, zinc smelting, carbon monoxide, cyanide and turpentine, among others, in January of 1911 documented 578 cases of lead poisoning. Several months later, Illinois passed a law requiring employers to protect their workers in the manufacture of brass smelting of lead and zinc. While at work on the Illinois report in 1910, Hamilton was invited to give a paper on the U.S. white-lead industry at the International Congress on Occupational Accidents and Diseases in Brussels. Hamilton felt embarrassed when the Belgian Labor Department criticized the U.S. lack of industrial hygiene practices.

Returning home, Hamilton met with Commissioner of Labor Charles Neill, who asked her to launch a nationwide investigation, beginning with the lead trades in 1911. But there were stipulations. She would not have the right to enter any factory unless she could convince factory owners to give her permission to enter their premises. While the commissioner offered no salary, he thought that the government would buy her final report at a price the government would set upon completion. Hamilton agreed.

“I have never doubted the wisdom of my decision to ... devote myself to work which has been scientific only in part, but human and practical in greater measure.”

By 1919, Hamilton, now a recognized authority in the field of industrial medicine, was sought out by Harvard Medical School Dean David L. Edsall. He had to convince the board at Harvard, aghast at the prospect of hiring a woman, that Hamilton was the best qualified person to join the faculty as an assistant professor. She agreed to the conditions not to attend commencement or football games, nor could she enter the all-male faculty club. Though she made light of her second-class citizenship at the all-male institution in her formal autobiography, private letters show the demoralizing effects of exclusion.

“Alice Hamilton has done her big work so quietly that many Americans have never heard of her,” wrote Edna Yost in her book American Women of Science in 1943. Hamilton helped launch the Journal of Industrial Hygiene in 1919 and published a major piece on lead poisoning in the first issue. Her textbook Industrial Toxicology was first issued in 1934. Hamilton retired in 1935 at the age of 66, but it would be another 10 years before women were admitted to Harvard Medical School as students.

Joe Brain, chair of the Archives Committee at the Harvard School of Public Health and co-author of The Education of Alice Hamilton (University of Indiana Press, November 2019) viewed Hamilton as a pioneering figure in public health.

“What I find most memorable about Alice Hamilton more than other historic figures in public health is that she always felt it was one thing to get data and do good science but then you weren’t really finished unless something happened ... unless you could use that knowledge to improve labor standards and other things that were necessary.”

Brain pointed to recordings of Hamilton’s interviews in which she described being a woman as a distinct advantage. He paraphrased: “Here I was this 5’3” woman dressed in black and when I would go to the factory gates as a woman, and say, I am interested in the health and welfare of your workers and your children, they’d let me in. They might ignore me or insult me but I had access. If a man showed up with the same request, they would not let him in.”

Brain added, “At five foot three dressed in tweeds and black, she looked harmless, but she was not.”