In the US, the impact of Social Security funding significantly aided the development of the industrial hygiene profession in the 1930s. For example, studies similar to those of Merewether and Price were conducted in the United States later in the 1930s; notably, one in 1938 by the USPHS that established the first airborne standard for asbestos dust and provided important information on the effectiveness of engineering controls in the workplace such as ventilation systems . This USPHS‐funded study was noted as one of the first uses of the newly available Social Security funds in the United States.
The establishment of professional associations to support the interests and growth of the profession has also played an important role in developing industrial hygiene as a science. The Michigan Industrial Hygiene Society (MIHS) and the American Conference of Governmental Industrial Hygienists (ACGIH) were founded in 1938. The American Industrial Hygiene Association (AIHA) was organized in 1939 and held its first annual conference that year and every year thereafter except 1945 (26).
Beyond those working in the USPHS, there were few industrial hygiene professionals in the United States in the 1930s, with a count by MIHS noting 160 members of AIHA as of 1940 with 32 or 20% in the Detroit area (26). It has been noted that Warren Cook estimated that there were only about 300 industrial hygienists in the United States in 1939 (27). One of the few industrial companies that had such capable professionals included the Standard Oil Company. The first major study of dust in the petrochemical industry was conducted by Bonsib in 1937 (28). Bonsib and his industrial safety and hygiene colleagues were clearly pioneers in such matters. Bonsib's report on such dusts predated even the first major USPHS study of the asbestos textile industry in 1938 (24). The report by Bonsib included measurements of at least 17 different kinds of dust but was generally focused on silica dust.
2.3 1940s: Publication of National Exposure Standards and Texts Buoyed the Profession
A book that included a foreword by Alice Hamilton and authored by Teleky in 1947, an authority on occupation hygiene in Europe at the time, provides a summary of the history of industrial hygiene from World War I to World War II (29). World War II was a major force in the development of the industrial hygiene profession. In 1943, the Division of Industrial Hygiene of the USPHS produced the Manual of Industrial Hygiene and Medical Service in War Industries. In 1940, the Industrial Hygiene section of the Industrial Medical Association first published the Journal of Industrial Medicine's Industrial Hygiene, and the AIHA began publishing the American Industrial Hygiene Quarterly. In 1942, the National Conference of Governmental Industrial Hygienists published a list of Maximum Acceptable Concentrations for a wide range of industrial materials as recommended by various State industrial hygiene units . In 1943, Alice Hamilton's book Exploring the Dangerous Trades was published (33). In 1945, the previously compiled list of various US state standards in place at the time was published by Warren Cook (34). In 1946, the ACGIH published the first Maximum Allowable Concentrations (by 1948 known as Threshold Limit Values [TLVs]) for workplace exposures to a wide range of 144 materials (35). TLVs were intended at the time, and continue to be today, concentrations at which “nearly all workers can be employed for their entire working lifetime without adverse effect.” (35) In 1948, the first edition of Patty's Industrial Hygiene and Toxicology was published (36). Patty's remains to this day a seminal publication and standard reference of the industrial hygiene profession.
2.4 1950s: The Growth of Employment of Industrial Hygienists in General Industry
The 1950s saw the increasing development of industrial hygiene programs within industry, particularly in large organizations. It was a time of growing concern about public and occupational health due to the noted increasing rates of cancer in the US populations. In 1953 in the United Kingdom, Doll published the first epidemiology study of the alarming increase in the rate of deaths from lung cancer. Several suspected causative factors were considered, and the result was a direct correlation between lung cancer and the smoking of cigarettes (37).
The first AIHA technical committees (air pollution, analytical chemistry, noise, and radiation) were formed, indicative of the broadening purview at that time of industrial hygiene to include environmental affairs as well as health physics.
Increased development of exposure standards in the 1950s continued to propel the profession. In 1951, the Walsh–Healey Public Contracts Act was expanded to include Safety and Health Standards that recommended a list of 29 ACGIH TLVs, to be used “as a guide for allowable concentrations.” This was the first specific Federal regulatory standard that expanded upon the generic requirements (for ventilation and respirators where appropriate) contained within the Basic Safety and Health Requirements added in 1942 to the original Walsh–Healey Public Contracts Act of 1936 (38). Outside of the United States, the profession also grew in developed countries. In the United Kingdom, the British Occupational Hygiene Society (BOHS) was founded in 1953.
In 1958, the AIHA published Hygienic Guides that included standards for 56 substances (39). This was the first time that the documented rationale behind the list of numerical TLVs exposure standards was widely published.
2.5 1960s: Certification of Industrial Hygienists Provides a Mark of Professional Recognition
In 1959, the Certification Committee of the AIHA recommended the establishment of a separate Board for certification of industrial hygienists, which became the American Board of Industrial Hygiene (ABIH). The 1960s saw the certification of 13 industrial hygienists, with 483 grandfathered by 1962. The first Certified Industrial Hygienist (CIH) examinations were held in Cincinnati, Ohio in 1963.
In the 1960s, there was a great increase in the sampling of workplace exposures. Sherwood and Greenhalgh were considered the first to build a practical personal sampling pump in 1960 (40),(41). The methods of sample analysis also greatly improved over the course of the 1960s. A surge of improved and sophisticated techniques for quantifying workers' exposures to health stress agents also generally took place in the 1960s. This progress applied to both sample collection and analytical techniques which resulted in much lower levels of exposure to specific agents being detected and quantified. There also began a dramatic increase in toxicological and epidemiological studies by government, industry, universities, and foundations, directed to obtaining data upon which to base exposure standards as well as improve industrial hygiene practices.
There had been significant differences in the methods of different industrial hygiene laboratories in the early twentieth century as well as among industrial hygienists conducting sampling in the field (42). Such significant differences continued well into the 1960s but began to be standardized (43). For example, fiber counting methods were standardized as of 1969 (44).
Environmental/off‐the‐job stresses were increasingly noted as elements of industrial hygiene. There was increased acknowledgment that workers may encounter a host of health risks outside of places of work. Lifestyle stresses were increasingly recognized as having the potential for a profound influence on health. As noted previously in Section 2.4, Doll showed the correlation between lung cancer and cigarette smoking. In addition to the primary cause of lung cancer from the smoking of cigarettes, stresses from other activities may have additive, accumulative, and synergistic actions, or may exert superimposed responses on the effects of other exposures arising in places of work. Recognition that these off‐the‐job agents could be causes of respiratory, cardiovascular, renal, or other diseases, and that they may create grave health problems in individuals over and above any effects of exposures encountered in workplaces continued to evolve.
The original authors of this chapter noted that a thought‐provoking