Louis Hempelmann

Louis Henry Hempelmann Jr, (March 5, 1914 – June 21, 1993) was an American physician who was the director of the Health Group at the Manhattan Project's Los Alamos Laboratory during World War II.

After the war he was involved in research into radiology.

Louis Henry Hempelmann Jr. was born in St. Louis, Missouri, on March 5, 1914, the son of Louis Henry Hempelmann Sr.

Both his father and grandfather were physicians.

He earned both his undergraduate and medical degrees from Washington University in St. Louis, from which he graduated in 1938.

He did his internship in pathology at Barnes Hospital in St. Louis, and then his residency at Peter Bent Brigham Hospital in Boston.

In 1941, Sherwood Moore, the director of Mallinckrodt Institute of Radiology in St. Louis, and a friend of his father, offered Hempelmann a position there.

The Mallinckrodt Institute was building a cyclotron in order to treat cancer patients with neutrons.

Hempelmann received a Commonwealth Fellowship to study at the University of California, Berkeley, where there was a cyclotron at the Radiation laboratory run by Ernest Lawrence, its inventor.

For the next four months Hempelmann worked with Robert Stone, who was treating patients with neutrons, and Lawrence's brother, John H. Lawrence, who ran the radioactive phosphorus clinic there.

While in Berkeley he met Robert Oppenheimer.

When he returned to the Mallinckrodt Institute, the cyclotron had been completed, but was being used to manufacture plutonium, so instead Hempelmann established a radioactive phosphorus clinic along the lines of Lawrence's one in Berkeley.

In early 1943, Hempelmann was summoned to a meeting in Chicago, where Oppenheimer recruited him to work on the Manhattan Project.

Oppenheimer asked Hempelmann if he could think of someone to run the Post Hospital, so Hempelmann approached James F. Nolan, a Washington University in St. Louis classmate who was studying at the Memorial Hospital in New York.

Nolan was trained in obstetrics and gynecology, which turned out to be useful.

Oppenheimer took the two doctors to see the Los Alamos Laboratory, which was then under construction, in March 1943, and Hempelmann moved there in April 1943, Nolan was subsequently commissioned as a captain in the Medical Corps, but Hempelmann remained a civilian.

As the head of the A-6 Health Group, he was responsible for occupational health and safety.

The Health Group set safe levels of exposure to hazardous chemicals and radioactive substances, and disseminated information about them.

It also kept records of hazards to which individuals had been exposed; Records of ordinary injuries were kept by the Post Hospital.

On June 5, 1943, Hempelmann married Elinor Pulitzer.

She was a granddaughter of the newspaper publisher Joseph Pulitzer, and a graduate of Mary Institute in St. Louis.

She had also attended a secretarial school.

They never had children.

Wives were encouraged to work at Los Alamos, so she became his secretary.

Hempelmann and Elinor became close friends of the Oppenheimers, and were godparents to the Oppenheimers' children.

Kitty Oppenheimer worked for Hempelmann as a laboratory technician, conducting blood tests to assess the danger of radiation.

The first year at Los Alamos was uneventful for the Health Group, which researched the extent of variation in blood counts.

The range of variation was found to be higher than expected.

This might have resulted in misdiagnosis of overexposure.

Serious health issues began to occur in 1944, with the arrival of the first samples of plutonium.

Plutonium is similar to radium in that it is deposited in the bones, where its alpha radiation may cause sarcoma, but while radium is chemically similar to calcium and becomes part of living bone, plutonium is deposited on the surface membranes.

It can also damage the kidneys.

Hempelmann visited a Boston luminous paint company to see how it was handled in industry.

When he returned he established three special committees in the Chemistry and Metallurgy Division: one to procure instrumentation to measure radioactive contamination; one to design equipment for handling plutonium; and one to develop standards and procedures for its safe handling.

An accident occurred on August 1, 1944, when chemist Donald Mastick ingested some plutonium when a vial he was handling exploded.

Mastick's face was scrubbed, but his skin remained contaminated with a microgram of plutonium.

Hempelmann gave him a mouthwash of trisodium citrate, which would combine with the plutonium to form a soluble liquid, and sodium bicarbonate, which would make it solid again.

This removed most of the plutonium.

Nonetheless, for days afterwards his breath could make the needle on an ionization chamber go off the scale, even from across the room.

A paper he published in the New England Journal of Medicine in 1949 warned of the dangers of using fluoroscopes to measure the size of children's feet.