|Description:||Toward the back of the photo, a row of workers in a Connecticut hat making plant shrink and shape hat felt into appropriate sizes. The plant was part of the 1937-1938 PHS industrial hygiene and engineering study of mercury exposure and its health effects in the hatmaking industry, which was published as USPHS Public Health Bulletin No. 263, Mercurialism and its Control in the Felt-Hat Industry, 1941. The process is noted in captions of several photos in the Bulletin” “The terms hardening, starting, wetting down, and sizing refer to successive stages in a shrinking process by which the hat body…is reduced to specific size by being wrapped in burlap, dipped in hot water, and kneaded by hand or on rotating rollers. About three-eighths of the employees of felt-hat factories are engaged in [these] operations.|
The average atmospheric mercury concentration was 2.1 mg. Hg per 10 M.3 air.” Note that on the low wood wall facing the camera is the stenciled instruction: “Please start this fan when kettles are heating up.” It appears, however, that steam from the kettles, which would be laden with mercury, is wafting freely in the atmosphere. Note, too, that the USPHS instrument used in this study to measure mercury vapor concentrations, sits on the wall above this instruction.
The NIOSH Historic Photo Collection began as the “picture file” of the Industrial Hygiene Division of the U.S. Public Health Service (USPHS), c. 1930-1960. It is a unique collection of mid-20th Century images of American workers and workplaces and documents occupational safety and health research of that era. The collection consists of approximately 1,000 original photographs and schematic drawings.