During this early period, workplace exposures were often significant, leading to a high prevalence of diseases and excess deaths. There were no major advances until 1473 when Ulrich Ellenborg published a pamphlet on occupational disease and gave instruction on hygiene. In 1538, Paracelsus, a Swiss alchemist, published considerable material on the toxicology of smelting metals (some of which was later determined to be incorrect) but his work led to the observation, “No substance is a poison by itself, it is the dose that makes a substance a poison,” (2) which formed the basis for the science of toxicology. The first scientific approach to occupational health was by Agricola in Latin in 1556 (3) and more than a century later, in 1700, Bernardo Ramazzini, an Italian physician, published a treatise on occupational disease, De Morbis Artificum, and coined the phrase still asked by occupational physicians, “Of what trade are you?” (4)
Although diseases caused by conditions of work have been recognized and treated for many hundreds of years, it was not until around the turn of the twentieth century that major efforts began to be directed toward what we now think of as fundamental industrial hygiene – the anticipation, recognition, evaluation, and control of workplace health hazards to prevent occupational disease. Scientists and practitioners, including engineers, chemists, and physicists, began to apply their knowledge and skills toward the development of methods and procedures for identifying, measuring, and controlling exposures to harmful airborne dusts and other chemical agents in workplaces. At that time, there were no consistent procedures for carrying out these activities.
Toward the mid‐twentieth century, management, labor unions, government, academia, and other groups took an increased and substantial interest in worker health and in the control of exposures to stresses in places of work. These external drivers of the progression of the field of industrial hygiene, along with the setting of standards for exposure limits, created a broad support for expanding knowledge and practice to prevent illnesses and diseases associated with on‐the‐job exposures.
Today, the theory and practice for anticipating, recognizing, evaluating, and controlling exposure to on‐the‐job and progressively off‐the‐job chemical, physical, and biological health hazards, as well as emerging research related to other environmental, physiological, psychological, and behavioral health hazards, define occupational/industrial hygiene. Industrial hygienists (IHs), together with a wide range of allied professionals, work to protect the health of persons exposed to workplace and community stressors.
2.1 The Early 1900s
During the early history of industrial development, a lack of knowledge of the effects of health stressors associated with industrial operations and how these could be controlled, with the concomitant substantial exposures to toxic materials in many places of work, led to serious episodes of illness, disease, and death among workers.
It was not until around the beginning of the twentieth century that specific attention began to be devoted to the preventive aspects of occupational illnesses. Early progress in Great Britain was made with dusts being a focus of such occupational and industrial hygiene efforts, as featured in the text Dangerous Trades by Oliver in 1902 (5). The 1916 text in the US edited by Kober and Hanson entitled Diseases of Occupational and Vocational Hygiene provided a contemporary view of the state of industrial hygiene in the United States at the time (6).
In the early 1900s, the major thrust in the control of workplace health stressors was directed toward those areas in industry having massive exposures to highly toxic materials. The professional talents of engineers, chemists, physicians, physicists, and statisticians were largely used in these efforts.
During this time, scientists and practitioners including engineers, chemists, and physicists, began to apply their knowledge and skills toward the development of methods and procedures for identifying, measuring, and controlling exposures to harmful airborne dusts and other chemical agents in workplaces. A general example is the high incidence of silicosis and silicotuberculosis that existed a century ago among workers in hard rock mines, the granite industry, and in tunneling operations, wherever the dust had a high free silica content. During this early period, the major effort on behalf of workers' health was to apply the knowledge at hand, which related primarily to the recognition and treatment of occupational illnesses.
There were several early efforts at organizing the profession in the United States during this time. The American Public Health Association (APHA) started a section on Industrial Hygiene in 1914, the US Public Health Service (USPHS) organized a division of Industrial Hygiene and Sanitation in 1915, and a group of occupational physicians formed the American Association of Industrial Physicians and Surgeons in 1916. The Journal of Industrial Hygiene in the United States was initially published in 1919, and the Harvard Schools of Public Health and Engineering established a program in 1927 for industrial sanitation that was important to the development of the industrial hygiene profession (7).
Choosing means for assessing levels of agents in air early in the twentieth century is a case in point in the need for advancement in methods and technologies to improve the practice of exposure assessment and industrial hygiene. The first standard method to measure dust in the work environment was developed in 1916 (8),(9). As a more specific example, in 1918, the first measurement of worker exposure to asbestos was recorded in the industrial hygiene scientific literature by Smyth . It was recognized at this time that various kinds of dust exist, and the harmfulness of the dust depends on both the nature of the dust as well as the amount, with the results of Smyth referenced by Greenburg in 1921 (13). The Greenburg Smith impinger dust‐sampling instrument was introduced in 1922 (14). Other instruments, such as the konimeter, Owens Jet dust counter, electrostatic precipitator, and evacuated containers, also came into use during this period. By 1923, the movement for the betterment of industrial conditions had taken on an international character. In the United States, groundbreaking occupational disease texts were published by Dr. Alice Hamilton in 1925 (15) and 1934 (16). Still, beyond the early pioneers such as Dr. Hamilton, specific knowledge of the hazards and industrial disease risks prior to 1930, as perhaps best described by Greenberg, was convoluted and unclear (17).
2.2 1930s: The Emergence of Industrial Hygiene as a Profession
By the 1930s, medical doctors, engineers, and others with relevant skills in industrial hygiene practice had begun working more closely together. The early field studies beginning generally in the 1930s showed that when the very high exposures of workers were lowered, there was a corresponding lowering of the related disease incidence in workers. These and other studies gave support to the dose–response rationale upon which the practice of industrial hygiene is primarily based, that is, that there is a dose–response relationship between the extent of exposure and severity of biological response to most stressors and in which the response is observable at some point.
For example, the first major development in the industrial hygiene history of asbestos occurred in 1930 when Merewether (a medical doctor) and Price (an engineer with occupational hygiene skills) of the British Inspector of Factories, published a significant study on asbestosis in the asbestos textile manufacturing industry (18),(19). This publication served as the first analysis that showed a relationship between the airborne concentration of asbestos and the incidence of pulmonary fibrosis disease. The basic industrial hygiene control methods that are still standard today were identified by Merewether and Price (18) and were incorporated into the first regulations that became effective in 1932 to limit factory worker exposure to asbestos in Great Britain (20).
The Hawks Nest Tunnel disaster in the 1930–1934 time period was a major event in increasing attention to industrial hygiene and occupational disease in the United States. In 1936, the US House of Representatives attributed 476 deaths to acute silicosis primarily from the drilling operations for the tunnel (21). By the late 1930s, the profession of industrial hygiene was emerging in the United States. In a 1937 book authored by medical doctors Ling and Nixon and printed in Great Britain, it was noted as the first sentence that “Industrial hygiene has in recent years come to assume an important place in both medicine and in industry” (22). In the United States, the Social Security Act of 1935 and the Walsh–Healy Act of 1936 had an immense impact on providing increased