Industrial Hygiene: A Foundational Role in Total Exposure Health

Dirk P. Yamamoto

Wright-Patterson Air Force Base

Introduction

Total Exposure Health (TEH) has origins as a US Air Force and Air Force Medical Service concept (see Chapter 1). To summarize, TEH recognizes that an individual, and his/her health, is influenced by more than just an occupational exposure. The health outcomes of each of us are, in theory, influenced by our occupational, environmental, and lifestyle-related exposures. In addition, our genetic profile can leave each of us predisposed for certain health outcomes, good or bad. TEH is individual-centric, due to the differences in exposure and genetic profile. It emphasizes that sensor technology, i.e., sampling and measurement, will be increasingly important to assess such a large set of exposures. It is theorized that when individualcentric exposure and genetic data are merged, more personalized healthcare is possible and will increase the well-being of individuals through prevention and other interventions.

Interestingly, industrial hygiene (IH) professionals have extensive skills related to assessment of occupational exposures and, arguably, many environmental exposures. These skills stand to be very important to TEH, with its holistic approach on assessing exposures around the clock. More specifically, industrial hygienists have practical skills in instruments with sensors aboard, designed to quantify exposures. Industrial hygienists stand to play a foundational role in TEH, and this chapter will cover the basics of the profession and will conclude with further discussion on how IH professionals can help with TEH and some challenges that might occur.

What Is Industrial Hygiene?

Definition of Industrial Hygiene

Traditionally focused on occupational exposures, i.e., those exposures occurring in an employer’s workplace, IH is a long-standing profession designed to protect worker health. The term industrial hygiene was likely first coined in the early 20th century, but examples of professionals looking out for the health of industrial workers dates back many centuries. Hazards faced by workers are generally classified as chemical, biological, or physical stressors. Examples of stressors include chemical vapors, gases, mold, asbestos noise, and ionizing radiation. Stressors can pose a hazard via various pathways, including inhalation, ingestion, and dermal absorption.

The American Industrial Hygiene Association (AIHA®) defines “industrial hygiene” as a “science and art devoted to the anticipation, recognition, evaluation, prevention, and control of those environmental factors or stresses arising in or from the workplace which may cause sickness, impaired health and wellbeing, or significant discomfort among workers or among citizens of the community” (AIHA 2019). The profession is often summarized by the industrial hygiene decision framework, which has tenets of anticipation, recognition, evaluation, and control (AREC) of occupational and environmental hazards. In more recent history, a fifth tenet, confirm, has been added to represent the importance of validating that exposure assessments of those exposures remain correct (Jahn et al. 2015).

OSHA Compliance

Additionally, the practice of IH is integral to compliance with safety and health regulatory bodies, such as the US Department of Labor’s Occupational Safety and Health Administration (OSHA). As a result of the Occupational Safety and Health (OSH) Act of 1970, OSHA was created to assure safe and healthful working conditions by setting and enforcing standards, and by providing training, outreach, education, and other assistance (OSHA 1970). Known as the General Duty Clause, section 5(a)(1) of the OSH Act states that each employer “shall furnish to each of his employees employment and a place of employment w'hich are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees” (OSHA 1970). Industrial hygienists and safety professionals work to ensure employers are in compliance with OSHA and, in doing so, help protect workers under those employers. Further discussion on OSHA appears in Section 5.3.3.4.

History of Industrial Hygiene

Early Names in IH

Centuries before the term “industrial hygiene” was even coined, there were numerous examples of professionals concerned about the health of industrial workers. Perhaps the earliest records of occupational disease were from Hippocrates, who around 370 BCE documented his observations regarding lead poisoning (Perkins 1997). In 50 CE, Pliny the Elder, a Roman author, philosopher, and army commander, recommended the use of animal bladders as pseudo-industrial “respirators” to protect against inhalation of toxic dusts from mining operations. In 1556, De Re Metallica, by Georgius Agricola (1494-1555), was published posthumously (Perkins 1997). It was believed to be the first comprehensive book on the mining industry based on field research and observation (“the scientific approach”) (Hoover and Hoover 1950). In the book are detailed descriptions of industrial processes, prevalent diseases, types of accidents, and preventive measures including rudimentary ventilation systems (i.e., “engineering controls”) (Blunt et al. 2011). With detailed hand-drawn pictures of mining and metallurgy, Agricola’s book remained the only authoritative reference on mining and metallurgy for over 200 years.

Other notable names important to the history of IH (and occupational medicine) include Paracelsus, Ramazzini, and Percivall Pott. In 1567, Paracelsus (“Father of Toxicology”) described mercury poisoning in extensive detail (Anna 2011). Later in 1713, Bernardino Ramazzini published what is believed to be the first book on occupational diseases, De Morbis Artificum Diatriba (Discourse on the Disease of Workers) (Blunt et al. 2011; Perkins 1997). In his book, Ramazzini described diseases of certain types of workers, such as seafarers, soldiers, salt workers, lawyers, and others. His descriptions included details on the conditions and hazards associated with the various diseases, along with principles to prevent disease (Perkins 1997). Ramazzini is credited with having the intuition to ask the important question, “what is your trade?” to better understand worker exposures and resulting diseases. In 1775, Percivall Pott, an English surgeon, deduced that scrotal cancer among

English chimney sweeps (a.k.a. Chimney sweepers’ carcinoma) was due to exposure to soot from coal combustion (Anna 2011).

Dr. Alice Hamilton (1881-1972) is widely regarded as a pioneer in both IH and occupational medicine. Although a physician, she is often regarded as being the first industrial hygienist as she pioneered and vigorously promoted hygiene in industry (Perkins 1997). During her career, Hamilton studied diseases associated with lead, mercury, carbon monoxide, aluminum, beryllium, cadmium, chromium, benzene, methanol, carbon disulfide, and synthetic rubber exposures. One of her greatest contributions was her study of “phossy-jaw”, the extremely disfiguring disease of the human jawbone due to exposure to phosphorus during the manufacturing of matches (Perkins 1977). Her book, Exploring the Dangerous Trades (Hamilton 1943), chronicles many of her occupational health findings during her career and remains a classic publication for the IH profession.

Academic Programs and ABET

The first academic program for IH was developed at Harvard University in 1918 and, coincidentally, is the university where Dr. Alice Hamilton became the first female faculty member (Blunt et al. 2011). With the increased emphasis on IH and worker protecting came an increase in the number of IH-related academic programs during at least the first half of the 20th century. There are currently 19 undergraduate- and graduate-level IH programs accredited by ABET, as of October 2019 (ABET 2019a) and note also that there are likely dozens of other programs for IH or IH-related degrees which are not ABET accredited. Well regarded around the world, ABET is an ISO 9001-certifed, nonprofit, nongovernmental agency that accredits programs in applied and natural science, computing, engineering, and engineering technology (ABET 2019b). Being accredited by ABET signifies that an academic program meets certain quality standards with regard to what students experience and learn. ABET relies on over 2,200 experts from industry, academia, and government to serve as program evaluators, commissioners, board members, and advisors for accreditation of academic programs (ABET 2019b). With assistance from member societies related to specific degree programs, ABET has established specific accreditation criteria against which individual academic degree programs are evaluated. For IH and similarly-named programs, AIHA serves as the member society which helps oversee the accreditation criteria for IH academic programs.

Professional Organizations

American Conference of Governmental Industrial Hygienists (ACGIH®)

As the IH profession grew during the early 1900s, two major societies emerged in support of the profession of IH and its practitioners. On June 27, 1938, the National Conference of Governmental Industrial Hygienists was convened in Washington D.C. with a limit of two representatives per governmental agency accepted as a member. In 1946, the organization changed its name to the American Conference of Governmental Industrial Hygienists (ACGIH®) and membership was expanded to all IH personnel in select US governmental agencies, along with governmental IH professionals in other countries. Today, ACGIH remains a nonprofit scientific organization dedicated to the advancement of occupational and environmental health with over 3,000 members (ACGIH 2019b). Membership has expanded to be inclusive of all professionals in IH, occupational health, environmental health, and safety in the United States and abroad. Regarding its organizational content, ACGIH currently has nine committees focused on various health and safety topics to advance the IH profession and support its membership. ACGIH is well known for its exposure guidelines, called Threshold Limit Values (TLVs®) and Biological Exposure Indices (BEIs®) (ACGIH 2019a, 2019b), which are used by IH professionals worldwide. The organization has many publications and educational courses to support the IH profession and also co-sponsors the well-regarded Journal of Occupational and Environmental Hygiene (JOEH) with the AIHA. Further details on ACGIH are available at their website, www.acgih.org.

American Industrial Hygiene Association (AIHA®)

The second major professional society for IH is the AIHA®, which was founded in October 1939. AIHA is a “nonprofit organization serving professionals dedicated to the anticipation, recognition, evaluation, control, and confirmation of environmental stressors in or arising from the workplace that may lead to injury, illness, or affect the well-being of workers and members of the community”. AIHA provides a wide variety of education, training, working groups, committees, publications, and services such as laboratory accreditation to benefit the profession of IH. AIHA has nearly 8,500 members in the industrial, consulting, academic, and government sectors (AIHA 2019). Its annual American Industrial Hygiene Conference and Expo (AIHce EXP) is a premier destination to share new ideas and learn new strategies to protect worker health. Signature publications, such as The Occupational Environment: Its Evaluation, Control, and Management (Anna 2011) and A Strategy for Assessing and Managing Occupational Exposures (Jahn et al. 2015), are important educational and reference tools for industrial hygienists. Further details on AIHA are available at their website, www.aiha.org.

Board for Global EHS Credentialing (BGC®)

In 1959, the AIHA Certification Committee recommended a separate board be created for the certification of industrial hygienists, which led to the creation of the American Board of Industrial Hygiene (ABIH®). ABIH was founded in 1960, as an independent not-for-profit organization dedicated to protecting the public through the certification of IH professionals with the Certified Industrial Hygienist (CIH®) credential. The first exams for certification were administered in 1963. Today, eligibility requirements for applicants include certain academic degree, coursework, and experience requirements before being eligible to take the exam. The CIH is an ANSI ISO/IEC-accredited credential, currently held by over 6,800 diplomates worldwide (ABIH 2019). In 2019, ABIH was rebranded as the Board for Global EHS Credentialing (BGC®), which is the new larger organizational name to represent a growing line of credentials focused on environmental, health, and safety. These credentials include the CIH®, Qualified Environmental Professional® (QEP®),

Environmental Professional In-Training® (EPI®), and the new Certified Professional Product Steward™ (CPPS™) credential. The mission of BGC is “To be the leader in offering credentials that elevate the technical and ethical standards for professionals practicing the science of protecting, managing, and enhancing the health and safety of people and the environment” (BGC 2019).

Occupational Safety and Health Administration (OSHA)

The OSH Act of 1970 created both the OSHA and the National Institute for Occupational Safety and Health (NIOSH). Officially established a year later (1971), OSHA is an agency of the US Department of Labor, created to ensure safe and healthful working conditions for working men and women by setting and enforcing standards, along with providing training, outreach, education, and assistance (OSHA 2019). As discussed previously, the General Duty Clause, section 5(a)(1) of the OSH Act, requires that the employer provide “a place of employment which are free from recognized hazards that are causing or are likely to cause death or serious physical harm to his employees” (OSHA 1970). To understand the positive impact of OSHA, recognize that in 1970, there were an estimated 14,000 US workers killed on the job, as compared to only 4,340 killed in 2009 (OSHA 2019).

Beyond the General Duty Clause, OSHA issues many standards (i.e., “regulations”) for a wide variety of workplace hazards. These standards are published in Title 29 of the Code of Federal Regulations (CFR), under four major categories of General Industry, Construction, Maritime, and Agriculture and are available at the OSHA webpage, www.osha.gov (OSHA 2019). Examples of IH-related standards are 29 CFR 1910.134 Respiratory Protection, 29 CFR 1910.146 Permit-Required Confined Space, 29 CFR 1910.1001 Asbestos, and 29 CFR 1910.1027 Cadmium. These standards describe the general requirements to maintain compliance, with some standards being hazardous substance-specific and others being program- specific. As a program-specific standard, 29 CFR 1910.134 Respiratory Protection is fairly comprehensive, with enough discussion possible that a separate text was authored (Racz et al. 2018). Note that in the absence of a specific standard for a hazard, employers are still required to comply with the General Duty Clause, i.e., keep their workplace free of serious recognized hazards (OSHA 2019). Related to standards, OSHA adopted its first permissible exposure limits (PELs) in 1971 and these were based on the 1968 ACGIH TLVs® (AIHA 2019).

National Institute for Occupational Safety and Health (NIOSH)

As mentioned previously, the OSH Act of 1970 also created the NIOSH. NIOSH was established as a research agency focused on the study of worker safety and health, along with empowering employers and workers to create safe and healthy workplaces (NIOSH 2019a). After its creation in 1970, NIOSH was transferred to the Centers for Disease Control (CDC; now, Centers for Disease Control and Prevention) from the then Health Service & Mental Health Administration. In 1974, the NIOSH (and OSHA) Standards Completion Program was the basis for 387 new standards (NIOSH 2019a). In 1977, the first nine NIOSH Education and Research Centers (ERCs) were awarded to major universities across the United States (note: as of October 2019, there are now 18 ERCs). These ERCs help translate scientific knowledge into practice through various education, training, and outreach programs. In 1978, the first edition of the NIOSH/OSHA Pocket Guide to Chemical Hazards was published (NIOSH 2019a) and, today, this publication is commonly referenced for its information on chemical properties and hazards. Over the years since its creation, NIOSH has developed numerous documents and other knowledge products covering health risks related to chemicals.