The Middle Ages of IAM (1974—1985)

The “middle ages” of IAM (1974 – 1985) marked the beginning discussions leading to a new definition of IAM, and new directions trending toward less autonomy and greater integration of IAM within in the Department of Preventive Medicine and Environmental Health (DPMEH).  In addition, this period marked new directions in research and teaching.  When I came “back home” to the IAM on faculty appointment in 1973, I was recruited and then challenged to take over the Comparative Medicine Section and start a graduate teaching program in Agricultural Medicine.

Administrative arrangements during the middle ages of IAM

Prior to the IAM, the DPMEH was a small Department, with only five faculty (Dr. Top, Dr. Ken McDonald, Mark Powell, Dr. Shu Ying Li Hsu and Dr. Hsi Fan Hsu).  With the founding of the IAM, resources became available that resulted in more than doubling the size of the faculty and staff in the Department of Preventive Medicine and Environmental Health (DPMEH). The additional personnel added expertise in environmental health, biostatistics, and epidemiology. The DPMEH became a more robust department adding expertise encompassing three of the five areas common to colleges of public health.

During the Foundational years, Dr. Top was the Head of the DPMEH and also the Director of IAM. Change in administration began when Dr. Top retired in 1970.  Dr. Keith Long became Department Head from 1970 – 1972, and Knapp directed the IAM from 1970-1974.

During this period, research became segmented along different lines. This created natural organizational divisions within the IAM. The study of zoonotic infectious diseases, pesticide toxicology, and accident prevention remained major research areas.  Previously mentioned, Section Chiefs were appointed to direct those areas of research. Knapp was appointed Chief of Accident Prevention, Dr. Long, Chief of Toxicology, and Donham, Chief of Comparative Medicine. Two new research and service areas developed within the Comparative Medicine Section 1) occupational and environmental health hazards associated with confined swine and poultry production feeding operations (CAFOs) and 2) selection of animal models to study human disease and diagnostic pathology to support animal model studies. Dr. Joel Leininger DVM PhD, board certified pathologist, was hired to support the research and service activities of the Comparative Medicine Section.

Dr. E. Peter Isaacson MD was recruited from the State University of New York, Buffalo in 1973 to head the DPMEH and served until 1985. In 1975, Isaacson abandoned the Section Divisions within IAM. The general trend of Dr. Isaacson’s management during his tenure was to develop the DPMEH with more balance with three principal components (Epidemiology, Biostatistics, and Environmental Health).  Dr. Isaacson brought in Robert Wallace MD MPH with him from the State University of New York at Buffalo. Wallace previously served as an Epidemiologic Intelligent Service officer (CDC) in the state of New York. Dr. Wallace later headed up the newly designated Epidemiology Division. Dr. Isaacson hired Dr. Tony Lachenbruch (taking over for Paul Leaverton) to enhance expertise in the areas of epidemiology and biostatistics, and to establish a Biostatistics Division. The IAM and was placed (in name) within the newly coined Division of Environmental Health of DPMEH.  Dr. Long was appointed Director of IAM in 1975, taking over from Pete Knapp, and served in that capacity until 1983.  Long also was appointed the Associate Department Head in that time period, which gave the IAM a closer association with the Department as a whole.  Following Dr. Isaacson’s retirement, Robert Wallace became Department Head in 1985, and served in that capacity until 1994.

During this period, faculty meetings of the newly coined Division of Environmental Health were dominated by discussions seeking new directions and a new definition and role for IAM, along with development of an educational program in Agricultural Medicine and Environmental Health. Research on new topics outside of agricultural occupational health and safety emerged. This included toxicology of formaldehyde-based insulation and building materials, led by Dr. Clyde Frank PhD, whose principal appointment was in chemistry, but had a secondary appointment in DPMEH.  Frank was aiming to start a new section in the IAM – environmental chemistry.  In the Accident Prevention Laboratory, Knapp and colleagues were involved in the development of the slow-moving vehicles sign (SMV). This warning sign became a nearly national universal sign that by law is to be attached to the back of a tractor or towed farm equipment that travels less than 20 miles per hour. This important signage has likely prevented numerous crashes between faster moving cars and trucks on the roadways.  Further work on-going in the Accident Prevention Laboratory under the direction of Knapp, included, epidemiological research on the causes and prevention of tractor overturns and power take-off injures. Also, they were involved in research on children’s flame retardant clothing and riding lawnmower safety.

Principal Faculty and Staff During the Middle Ages of IAM

Dr. Long, Pete Knapp, and Dr. Berry were “holdovers” from the foundational years. New faculty hired during the period included Kelley Donham MS DVM DACVPM, Dr. Donald P. Morgan MD, PhD, James Merchant MD DrPH, William Popendorf PhD CIH, and Peter Thorne PhD.

Dr. Morgan was a physician who came from the University of Arizona and private medical practice before that. Dr. Morgan was found by Long who directed Iowa’s Community Pesticide Study Program (CPSP). Long took a leave of absence from the IAM to work for the Center for Disease Control to evaluate the laboratories of the fourteen National Network of CPSP programs. While evaluating the program in Arizona where Dr. Morgan was working, he learned that program was closing.  Dr. Long encouraged Dr. Morgan to come and work in the Iowa CPSP.  Dr. Morgan did come.  He was an apt fit for the IAM.  He was a respected researcher, scholar, and teacher.

The CPSP was a CDC-funded program designed to establish long-term ecologic and epidemiologic studies to determine the health effects of pesticides on humans.  Dr. Long directed the CPSP at Iowa beginning in 1965.  Fourteen other states (those with high use of pesticides) had CPSPs during the 1970s.  The program at IAM was in collaboration with the Iowa State University College of Veterinary Medicine in Ames, Iowa.  Dr. Gary Van Gelder DVM PhD was a professor in the College of Veterinary Medicine and the Assistant Director of the Iowa CPSP.  One of Dr. Morgan’s most important contributions was research on assessing urinary metabolites of various pesticides as a diagnostic tool for exposure. One of his most important contributions was serving as author and editor of the EPA Manual of Recognition and Management of Pesticide Poisonings  4thEd. (Morgan 1989).  This manual is now in its sixth edition.  Although now authored and edited by others, it remains a mainstay in the field for health professionals at all levels who care for workers who may have contact with pesticides.

Late in this period (1981) Dr. James Merchant MD, Dr.PH. was hired.  As mentioned earlier, Dr. Merchant had Iowa roots, having grown up in Ames, Iowa where his father (Dr. I.A. Merchant DVM) was the Dean of the Iowa State University College of Veterinary Medicine.  James Merchant received his medical training at the University of Iowa and postgraduate training in internal medicine at Cleveland Metropolitan General Hospital, pulmonary and environmental medicine training at Duke University, and DrPH in epidemiology at the University of North Carolina School of Public Health. He completed post-doctoral training  at the Cardiothoracic Institute, University of London. He served as an Epidemiologic Intelligence Officer (CDC). Later he served at NIOSH in Morgantown, West Virginia, where he directed the NIOSH Appalachian Laboratory for Occupational Safety and Health, Division of Respiratory Disease Studies. One of his principal areas of work at NIOSH was cotton dust exposure which causes the occupational respiratory disease byssinosis in textile and ginning mill workers. Dr. Merchant’s interests, along with my interest and experience in respiratory conditions of swine confinement workers, helped to develop a new area of research in agricultural respiratory diseases at the IAM.  (Research activities will be discussed in more detail later under the topic of research).  In 1983, Dr. Merchant was appointed the Director of the IAM, taking over from Keith Long.  In that same year, Dr. Merchant was appointed Division Director of Occupational and Environmental Health. In 1997, Dr. Merchant was appointed Head of the DPMEH. Major changes in the IAM occurred under Dr. Merchant’s tenure.

Dr. William Popendorf PhD, CIH, was hired from the School of Public Health at U.C. Berkley. Dr. Popendorf had previously worked in the area of agricultural worker exposure to pesticides. As Dr. Berry retired, Dr. Popendorf also took responsibility for the IH training program which Dr. Berry had founded. Popendorf continued work in the area of pesticides and branched off to work with Donham in the area of the work environment in intensive swine housing.  He also modernized and expanded the curriculum of the Industrial Hygiene Program.

Development of Agricultural Medicine Education Programs During the Middle Ages

Early on, there were no specific courses or curriculum in Agricultural Medicine. Educational efforts were ad hoc. There were single and sometimes topical lectures in response to invitations from other organizations, academic colleges, or departments.

In 1974,per my charge when hired, I began to build whole courses and an entire curriculum in Agricultural Medicine. The first offering was a lecture series in Agricultural Medicine to sophomore medical students. These lectures included what I considered were the major topical areas in the field (i.e. acute traumatic injuries, respiratory diseases, hearing loss, skin conditions, toxicities from agricultural chemicals, and general rural environmental health hazards). This series of lectures evolved into a week-long “mini course” in Agricultural Medicine within the general public health course for sophomore medical students. As there were no general resources for teaching in this field, I sought support to develop teaching materials for an Agricultural Medicine curriculum. We were awarded a grant from the National Fund for Medical Education to write the first textbook in the field. The book was Medical Practice in Rural Communities  (Mutel and Donham 1983). This book was specifically written for health sciences students. The intent was that his text would be inserted into an ongoing course of public/environmental/rural health for a variety of health care science students e.g. medical, nurse, PA, pharmacy students, veterinary.

The need for this mini course in Agricultural Medicine training was supported by evidence that none of the rural health training programs in the U.S. included training in Agricultural Medicine. They focused only on delivery of general primary health care in a rural setting.  My observations indicated that agricultural medicine training was absent in health sciences education. I thought such training was important to prepare providers to best serve the health needs of rural farming communities.

Based on the experience writing Medical Practice in Rural Communities and with funds from the National Fund for Medical Education, we developed materials to provide distant training to other colleges and to individuals – nation – wide. The Rural Health Audiovisual Series was a set of 16 slide-audio-tape presentations (1,250 slides in the series) that presented core hazards and clinical information of occupational hazards of agricultural workers. Two of our IAM staff, Cornelia Mutel MS (a science writer), and Carol Hradek (photographer) helped produce this educational program. This program was designed for use in a classroom as well as for distance-learning continuing medical and nursing educational credits.  The series was distributed nationally by the National Audiovisual Center of the National Library of Medicine, Washington DC.

Based on the developed teaching materials and the mini course for medical students, I further expanded the program  into “The Rural Health and Agricultural Medicine Training Program.” This program was aimed at wide variety of health science students, and practitioners.  For medical students, in addition to the weeklong mini course, it consisted of a month-long rotation in the IAM that offered exposure to research and outreach in the field. Students in the medical, nursing, physician assistants, and veterinary medicine were offered the same training (a one health program).  A graduate academic program was offered for the MS or PhD degree, which required the student to take all core courses required of the Environmental Health program, plus research training in agricultural medicine, and an accompanying thesis or dissertation on an agricultural medicine topic. The educational program in agricultural medicine continued to progress in future years of the IAM and will be discussed further in the New Directions section of this text.  An informational brochure on the program titled Rural Health and Agricultural Medicine Training Program (Donham 1983) is provided in Appendix C .  

Research at the IAM During the Middle Ages (1974 – 1985)

Research in Pesticide Toxicology

The Pesticide Toxicology Section continued to prosper during this period under Dr. Long and Dr. Morgan’s leadership. Dr. Morgan continued to serve as author and editor of Recognition and Management of Pesticide Poisonings.  Dr. Morgan also continued research on methods for measuring pesticides in body fluids (Morgan, Hetzler, Slach, and Linn 1977).  This new emphasis was important in helping to diagnose pesticide exposure to several classes of pesticides. Previously the primary insecticides in use were cholinesterase-inhibiting compounds (organophosphates and carbamates). Methods to detect these exposures had limitations based on specificity of the test and the time lapse following exposure.

The Community Pesticide Studies Program of the EPA (1970- 1990’s) was a grandparent of the Agricultural Health Study (AHS).  The AHS is the most comprehensive study to date on the health effects of pesticides. The National Cancer Institute, the EPA, NIOSH, and the National Institute of Environmental Health Sciences collaboratively fund the AHS. Dr. Charles Lynch MD PhD has led Iowa’s component of the project begun in 1993. Additional pesticide research goes on currently in the College of Public Health, as of 2021.  For example, Diane Rohlman PhD investigates pesticide exposure to young agricultural workers in Egypt. Details of the AHS and the Egyptian pesticide study will be detailed in the modern times, and current times section of this text.

Dr. Long and the toxicology section staff of the IAM became participants in research on one of our nation’s critical environmental contaminations (Kay 1977).  In 1973, an unintended event in Michigan led to contamination of livestock feed with polybrominated biphenyls (PBB).  Bags of polybrominated biphenyls (PBB), used mainly as a fire retardant, were mislabeled as dicalcium phosphate (a normal additive to livestock feeds).  This resulted in PPB contaminating animal feed on 500 farms. By way of the food chain, PBB was found in the tissues of thousands of cattle, swine and poultry. This substance is very stable; it is stored in fat tissue and excreted in milk. People consuming meat and milk from these contaminated animals became ill (MDCH 2011).  This event was recognized as a serious public health concern during the period 1973 – 1974.  PBB is a hormone disrupter. It affects fertility, thyroid function and brain development among other conditions. PBB was removed from the market in 1976. Dr. Long and staff of the IAM, collaborating with the Michigan State Department of Health, led an important component of the public health surveillance of PBB exposure. The IAM contributed to the surveillance of this issue with laboratory analysis of PBB in human and animal tissues and environmental and epidemiologic consultation.

The experience with PBB’s helped provide a national awareness of similar chemicals that led to environmental problems. This awareness and concern led to the formation of the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), commonly known as Superfund, which was enacted by Congress on December 11, 1980. The link between the former University of Iowa research in the 1970s reemerged as a program in more recent times. Iowa was able to attract and retain the Iowa Superfund Research Program, one of 18 Superfund Multi-project Centers Programs in the U.S. today.  The Iowa center is located in the IAM (now IREH) facility and has been under the leadership of Dr. Larry Roberts. In 2018, the PI was transferred to Kerri Hornbuckle PhD in the College of Engineering. The primary environmental contaminant studied in this center is Polychlorinated biphenyls (PCB). These chemicals are very similar in the chemical and biological risk characteristics to PBBs.  PCBs were used primarily in commercial electrical transformers and transistors as insulators and fire retardants, among many other uses. They were banned in 1979.  In summary, studies of this class of chemicals at the IAM in 1973 as an agricultural contaminant and public health hazard, came back to the IAM with the Superfund Project.

Research in Accident Prevention

During the middle period, research in Accident Prevention continued to focus on acute injuries associated with agricultural machines. Pete Knapp had established a very effective surveillance system called the  Rural Family Accident Study.  This study involved accessing multiple sources of information to identify injury events. Those sources included the Extension Service, rural fire departments, first responders, law enforcement agencies, newspapers, and cooperating rural physicians and hospitals (Knapp 1963, Knapp 1966).  Of these sources, the medical community was the most effective source in reporting farm accidents. He had developed relationships with a network of some 250 rural physicians in the state. They would notify Knapp when an acute agricultural injury occurred to one of their patients. When injury events were identified by any of these sources, field investigators were deployed to investigate them in detail to determine the man-machine-environment interactions that resulted in the event.  Often on-site investigations led to further research. As these cases accumulated, they were studied in aggregate using epidemiologic methods to find trends and associations that would lead to clues in prevention. Although William Haddon has been considered by epidemiologists as the  “father” of the application of epidemiology to injury prevention,  Knapp and staff were perhaps ahead of him in this application and certainly the first to use epidemiology to study the cause, effects, and prevention of agricultural acute injuries.

Research in The Comparative Medicine Section
Leukemia among farmers

I became interested in the most common cancer in dairy cattle (Bovine lymphosarcoma [BLS]) during my time in the College of Veterinary Medicine at Iowa State University. There, as a student, I conducted an epidemiologic study in cattle and found the disease followed an infectious disease pattern rather than a non-infectious disease pattern (Donham and Hull 1971). This experience propelled me to further pursuit of this subject while a young professor at IAM. I worked with Drs. Janice Miller DVM, PhD, and Dr. Martin van der Maaten DVM, PhD at the National Animal Disease Center in Ames, Iowa. They found that a virus (the bovine leukemia virus [BLV]) was the cause of BLS in cattle (Miller and van der Maaten 1977, and Miller and van der Maaten 1982). This RNA virus is closely related the type-2  human T-cell leukemia virus (HTLV-2) which is associated with human leukemia and several other conditions in humans (Goncalves, Proietti, Ribas, et al. 2010).  Following on with that interest at the IAM, I found important resources in DPMEH that would allow the study of the potential public health risk of this disease. Dr. Charles Lynch, professor in the DPMEH at Iowa, directs the Iowa Cancer Registry, on contract from the State Department of Health.  Also, he directs Iowa’s component of the AHS. The Cancer Registry provided support for cancer epidemiologic studies. We observed that farmers had greater morbidity and mortality due to leukemia relative to the general population. In addition, we found epidemiologic evidence that the bovine leukemia virus is transmissible among cattle.

During this time, a serologic test was developed to identify infected cattle. The disease was found to be much more common in dairy cattle than in beef cattle. In our serologic surveillance of Iowa dairy cattle, we found that 33% of those tested were positive for evidence of infection with the BLV (Donham, van der Maaten, Miller, Kruse, and Rubino 1977).  Further, it was found that BLV could be transmitted to calves in milk from infected cattle. Also, it was found that BLV can cross species barriers to sheep and goats through feeding them milk from infected cattle. We then asked the question whether the milk from infected cattle also could cause the observed excess leukemia rates in the farm population.  It has been common practice for farm families to drink milk from bulk tanks on their farms without pasteurization.  We surveyed dairy farmers and found that 80% reported they consumed milk unpasteurized from the cows on their own farms. We conducted a geographic-ecologic study and found that leukemia in Iowa farmers was found at a higher prevalence in the Northeastern part of the state. This part of Iowa is the principal area of dairy farms. We (with graduate student Mike Rubino) carried out research to determine if the BLV could remain viable in milk for at least three days. The three-day threshold was chosen because dairy processors pick up milk from the bulk storage tanks on dairy farms every three days. Rubino’s dissertation research demonstrated that the virus can remain viable in unpasteurized milk for at least three days. Ecologic evidence suggested that farm families may be at risk for leukemia from drinking unpasteurized milk. However, Rubino also found that the virus does not survive pasteurization (Rubino and Donham 1984).  Although we found ecologic evidence suggesting an association between BLV and human leukemia, we recognized that further studies were warranted before we could claim there was cause-effect.

Work on this subject continued when we obtained a grant from the USDA, to work with Drs. Miller and van der Maaten to test the hypothesis of transmissibility of the BLV to hominoid species (includes apes and humans) and other primates. We exposed several species of apes and monkeys to see if the virus could be transmitted to them. We followed these animals over several years both by monitoring clinical signs, complete blood counts, bone marrow cytology, and serologically.  We found the exposed chimpanzees seroconverted from negative to positive BLV antibodies, and had a white blood cell differential shift in the neutrophil to lymphocyte ratio in their blood and bone marrow (that is, relatively more lymphocytes compared to neutrophils) suggestive of a pathologic change in their blood profile.  However, no other clinical signs in the animals exposed to BLV were noted— except in one of the chimpanzees.  That animal developed thickened external ear margins, lips, eyebrow ridges, and other thickened skin facial features. Preliminary histological studies of biopsy of affected tissues by our veterinary pathologist on the faculty at the time, Joel Leininger DVM, PhD, noted that the lesions were infiltrated with acid fast bacteria. We referred the pathologic samples for consultation to a colleague, Professor John Kluge DVM, professor of veterinary pathologist at Iowa State University College of Veterinary Medicine. He said, “This looks like leprosy in humans.” This finding was startling as it was previously thought that leprosy was only a disease of humans.  Further consultation with human leprosy experts indicated that this was in fact leprosy, (the lepromatous disseminated form).  We reported this finding in several peer reviewed journals (Donham and Leininger, 1977, Leninger, Donham, and Rubino 1978, Leininger, Donham and Meyers 1980). This was a noteworthy because our chimp was first case of leprosy found in a non-human primate. However, about this same time, leprosy was found in armadillos in southern U.S.  Some years later after our finding, leprosy was found in other primate species. Our lepromatous chimp opened the door to the question of the relationship of the infection with the BLV and the resultant leprosy that we found in our chimpanzee.  Our clinical research on this chimp with leprosy identified it had T cell monocyte and neutrophil dysfunctions (suggestive of damage to the cellular immune system).  However, this chimp did not have leukemia or solid tumors. We followed all the BLV exposed primates over several years, but none of the others developed leukemia or leprosy. The chimp with leprosy came originally from native trader/trappers in Sierra Leon Africa, where leprosy in humans is very common. We hypothesized that the chimp had acquired a subclinical case of leprosy from human exposure in Africa. Further we hypothesized that the BLV damaged the cell-mediated immunity of the chimp, allowing the subclinical case of leprosy to develop to a severe clinical case of lepromatous leprosy. In vitro studies of the white cells from this chimp revealed a much slower immune response of his neutrophils compared to controls. This event led us to share tissue specimens for study from the affected chimp to other researchers around the world. The consensus of these leprosy researchers was that leprosy is a true zoonotic disease (Meyers, Binford, Gormus et. al. 1988).  Further we concluded that BLV, although it may not cause frank leukemia or lymphoma in humans, can possibly damage the cellular immune system, opening the door to other serious infections. Learning from this experience, we expanded our outreach education to farmers to not drink unpasteurized milk because of the potential risk for the exposure to the BLV, as well as several other infections transmissible through milk.

Swine Confinement and Occupational Health

Having grown up on a swine farm, and then working as a practicing veterinarian in swine medicine, I noticed that when working in swine barns, I would develop a tightness of chest, accompanied by wheezing and coughing. These symptoms worsened when working in large enclosed high-density swine facilities referred to as animal feeding operations or AFO’s. This change toward AFO-style production facilities began in poultry in the 1950s and then in swine in the late 1970s. I thought that if I, as a veterinary practitioner had respiratory symptoms, perhaps others who worked in these facilities did as well. Therefore, in 1974 at the IAM, we conducted a survey of veterinarians in Eastern Iowa relative to their health experience associated with work in AFOs. We found that 66% of veterinarians working in confined swine production had symptoms similar to my experience, including chest tightness, wheezing, and cough.  Based on this pilot investigation, we designed and initiated a more expansive survey of swine workers in Iowa which resulted in the first peer-reviewed publication in the world on this subject (Donham, Rubino, Thedell, and Kammermeyer 1977).

Shortly after this study was published, I received a call from a health care provider in eastern Iowa.  He indicated there had been a fatal incident on a swine farm. He wanted to know the cause. I arrived the next morning at the farm where the incident occurred and found a distressed farm wife who had just lost her husband and her two sons in a swine facility. They had been attempting to empty the liquid manure from a deep storage pit with a pump operated by the power take off from a tractor outside the storage pit. The pump malfunctioned. The father had climbed down into the pit to attempt to fix the pump. Within a few seconds, he fell into the bottom of the pit.  His elder son of 23 and younger son of 18 went into the pit to rescue their father. Both young men fell unconscious into the bottom of the pit while attempting to rescue their father. The fire-rescue service was called to retrieve the farmers. The father and both sons were pronounced dead at the local hospital. At the scene the next day, I measured lethal concentrations of hydrogen sulfide gas in the pit. I will never forget sitting at the kitchen table in the home of this farm family, explaining to the widow what happened and how she lost her entire immediate family.  She was in shock. The only thing she could do in the fog of her grieving was to offer me more coffee and fresh baked cookies that her sons and husband would not eat.

This tragic event was the first of this type that we were aware of.  However, many such acute hydrogen sulfide poisoning events followed as AFO-style production with liquid manure storage became more common replacing outdoor swine production with solid manure storage. We went on to investigate many such events, seeking to learn how and why they occur and how to prevent them. Stephanie Leonard (IAM staff industrial hygienist) and I investigated 19 such incidents subsequently. We published our findings (Donham, Knapp, Monson, and Gustafson 1982).  Only one other publication on the subject had appeared in the literature at the time (Osbern and Crapo, 1981).

These acute toxic poisonings combined with the chronic respiratory conditions I and others working in AFOs experienced led to 40 years of research at Iowa to fully characterize these conditions and find ways to prevent illnesses from AFO exposures. We were the first in the world to research the issues of these health risks of workers in swine and poultry confinement facilities. Collaborators at Iowa early on included Dr. Donald Zaval MD, James Merchant MD, DrPH, William Popendorf PhD, CIH, and John Kammermeyer MD.  Expanding our research at Iowa on the chronic conditions of AFO workers, we found these workers experienced a common group of conditions, including bronchitis, non-allergic asthma, and an acute condition called organic dust toxic syndrome. This foundational research brought international awareness to this problem, leading to collaborative research in several other research universities in the U.S., Canada, Sweden, Denmark, The Netherlands, Germany, Spain, France, and Australia.  We were consultants and collaborators in all these international studies. This research has led to engineering design changes in AFOs, education for prevention, utilization of monitoring air quality, recommendations for maximum exposures of air contaminants inside AFOs, and personal protective equipment recommendations. In recent years, the incidence of acute poisoning events from hydrogen sulfide in swine barns has decreased. In addition, air quality in some of the buildings has improved, suggesting the risk to workers of chronic respiratory conditions might decrease. However, the hazard remains for both acute and chronic health hazards. An effective research-to-practice portal from researchers to the industry has not been a robust as it should be. A few of the more than 30 articles on this subject published out of the research at IAM are listed here (Donham, Rubino, Thedell, Kammermeyer 1977, Donham, Knapp, Monson, Gustafson 1982, Donham, Zavala, Merchant 1984A, Donham, Zavala, Merchant 1984B, Donham Leininger, 1984, Donham, Popendorf, 1985, Donham, Yeggy, Dague 1985, Donham 1986).

This foundational research beginning in the 1970’s has been a “trail head” for current research in the Department of Occupational and Environmental Health, College of Public Health.  In more recent years (the 1990s and 2000s) other younger researchers at Iowa in DOEH and CPH have been active in this research. These researchers include Patrick O’Shaughnessy, Tom Peters, Mathew Nonnenmann, and  Rene’ Anthony (Peters, Anthony, and Taylor, e.t. al. 2012, Park, Peters, and Altmaier et. al. 2013, Nonnenmann, Donham, and Rautiainen, 2004, O’Shaughnessy, Donham, and Peters, et. al. 2010).  Current research in AFO and worker health include air quality control, task analysis, respiratory exposures, Methicillin -resistant Staphylococcus aureus (MRSA) from pigs, efficiency of respirators for workers, ventilation and dust mitigation, and development of “accessible” air quality monitoring instruments.

Outreach During the Middle Ages (1974- 1985)

Early in this period, there were relatively few resources available for research and training in agricultural health and safety.  One of the reasons was that relatively few federal policies for farmers’ occupational health and safety had been promulgated. The U. S. Department of Labor had promulgated mine safety regulations in 1952 (Federal Coal Mine Safety Act).  However, there had been little federal farm health and safety until 1974. That is when NIOSH began to show an interest in the issue. The IAM was an important change agent in this development.  Collaboration with NIOSH allowed the IAM to contribute to the growth of Agricultural Health and Safety nationally through outreach, modeling, consultation, and leadership.

To bring NIOSH up to date on agricultural safety and health, a contract was awarded to the IAM in 1974 to produce the State of-the-Art Report on Occupational Safety and Health in Agricultural (Knapp 1974).  Knapp led this two-year effort producing the 550-page document. This document served to put NIOSH on notice that agriculture is and has been for many years the first or second most hazardous industry for workers in the U.S. Contributors to this document included the following faculty and staff of the IAM: L.W. Knapp, K.J. Donham, F. Top, C. Berry, K. Long, P. Isaacson, L. Burmeister, W. McConnell, D. Mick, and D. Morgan.

Also in 1974, the IAM led the first national conference on agricultural safety and health in the U.S. held by a health-care institute. The Conference on Agricultural Safety and Health was directed by Dr. Berry and held in Iowa City, September 4 – 5, 1974. The conference attracted 156 attendees (Berry, Beard, Finklea, Lloyd, 1974). It was sponsored by the Society for Occupational Safety and Health, with additional support from NIOSH (Berry, Beard, Finklea, and Lloyd 1974). A 300-page proceedings was produced.

The impact of these two events (National Conference on Agricultural and Health and the State-of-the-Art Report on Occupational Safety and Health in Agricultural) clearly tagged the IAM and Iowa as the national leader for a medical and public health approach to occupational health of agricultural populations. This work in 1974 influenced NIOSH to recognize agricultural safety and health as a critical issue. This recognition facilitated important collaborative relationships between NIOSH and the IAM, resulting in the IAM serving to consult and collaborate on agricultural health issues with the Western Regional NIOSH office in Salt Lake City. During this time period the Western Regional Office of NIOSH was the focal point for NIOSH’s entry into the field of agricultural safety and health.  With the reorganization of NIOSH in 1977, agricultural health and safety leadership was transferred to the Division of Respiratory Disease Studies in Morgantown, West Virginia, then directed by Dr. Merchant. The threads of the connection and collaboration between the IAM and NIOSH can be followed up to the 1988 Agriculture at Risk Policy Process and the establishment of the NIOSH National Agricultural Health and Safety Program (which will be discussed later in the New Directions section of this text).  I feel fortunate to have participated in both of these landmark processes.

International Connections During the Middle Years (1974 – 1985)

The International Social Security Association (ISSA)

The ISSA is part of the International Labor Organization (ILO) that has a broad concern for the social well-being of all people; this includes an important focus on health and safety of agrarian people. The organization provides guidelines for administration of labor and other social issues. They have been one of the most important organizations in the European Community to advocate for farmers and hold conferences on the health and safety of farmers and farm workers.  Pete Knapp established an active professional relationship with the ISSA organization having contributed to various WHO publications on health and safety of farmers and their workers.

The International Association of Agricultural Medicine and Rural Health

Knapp, Top, Long and Donham were active in helping to establish sustainability of the International Association for Agricultural Medicine and Rural Health (IAAMRH).  The IAM faculty (primarily Top and Knapp) helped found this organization in 1961. Now called the International Association of Rural Medicine (IARM) it includes agricultural and rural health experts from different scientific disciplines to work toward sustainable health of the general rural population, as well as the occupational and environmental health of agrarian people. Members include scientists from North American, Western Europe, Eastern Europe, Japan, Korea, and India among others. This organization put the IAM faculty in touch with many health and safety professionals around the world. Early in this period (circa 1975), the IAM hosted the triennial conference of IAAMRH in Salt Lake City where the NIOSH Western Office was located. Also, the IAM faculty (mainly Long, Knapp, and Berry) had established collaboration with the scientists and administrators in the Western region. This conference further entrenched the IAM as an international leader in the field of Agricultural Medicine and assisted in strengthening the collaboration.

The Swedish Connection

An important international connection was established through collaboration with Dr. Anders Thelin MD, PhD of Sweden. Dr. Thelin was a visiting scholar at IAM in the late 1970s. Upon returning to Sweden, Dr. Thelin worked as an occupational medicine physician for the organization called Lantbrukshalsan (translated as farmers’ health).  This organization was a rural, multi-clinic preventive occupational health service for famers and their families. Dr. Thelin and the Lantbrukshalsan association became a critical model for programs and education for the IAM early in the modern ages of IAM.

In 1984, I received the Faculty Scholars Award from the University of Iowa. This award was based on two major aims: 1) to research the potential health concerns of Swedish swine producers, and 2) to establish an international workshop titled Health Effects of Organic Dusts in the Farm Environment.  Awards from the Swedish Work Environment Fund, and the Department of Environmental Health, the University of Gothenburg also supported this work. These combined resources allowed for a sabbatical research leave from the University of Iowa from August of 1984 to September of 1985. Dr. Ragnar Rylander MD was the Head of the Department of Environmental Health at Gothenburg University and my primary host and collaborator. We designed a detailed research project involving of 30 swine farms with 55 swine producers/workers in the southern counties of Sweden. This was the first such detailed study of the work environment of swine producer health in Europe modeled after our study of Iowa swine producers.  The study included respiratory health and general health screening of swine workers, detailed air quality assessment and related sources of emissions, as well as swine health and production parameters. This study resulted in establishing recommended threshold exposures of ammonia, endotoxin, carbon dioxide, total and respirable dust, and total bioaerosols for worker health. Additionally, this research was able to set air quality parameters for animal health and maximum production. These foundational studies set the stage for many further studies in Europe, Australia, and Canada.

The second part of the Faculty Scholars Award was to design and conduct an international workshop on agricultural respiratory diseases. We planned the International Workshop Health Effects of Organic Dusts in the Farm Environment, to be held in Skokloster, Sweden April 23 -25, 1985 (Rylander, Donham, Hjort, Brouwer, and Heederick, 1986) .  Up to this time, the main causes of acute occupational respiratory diseases were thought to be related to allergic conditions or chronic lung scarring from inorganic dusts (e.g. silica, coal dust, asbestos).  However, those of us working in the field recognized this was not the case among farmers. A condition called Farmer’s Lung had been reported in the scientific literature for a number of years. The pathogenesis was described as a delayed hypersensitivity reaction to respirable thermophilic bacterial organisms. However, we at the IAM and others were recognizing that farmers were experiencing a spectrum of non-allergic respiratory conditions; this was different from current thinking at that time among most occupational health professionals. Medical clinicians, among other occupational health professionals were working in “silos” limiting progress in the field of occupational respiratory diseases. We organized this conference with an unusual strategic plan – to break scientists out of their silos and to form a consensus on current knowledge of agricultural respiratory diseases. The strategy involved inviting 37 key scientists from the U.S., 10 European countries (Sweden, Norway, Denmark, England, Wales, Germany, Switzerland, Italy, The Netherlands, and Portugal), Japan, and China. The invitees came from different backgrounds and professional expertise. This was a true “one health” process.   The process included state-of-the-art presentations, abstract presentations, and workgroups with assigned questions. The keystone of the event was a final consensus process with the body as a whole aiming to come to unanimity on the specific questions. This collaborative one health approach was critical in establishing a new lexicon for the agents and resultant respiratory diseases in agricultural workers due to agricultural dust exposures.

The consensus process resulted in the classification of agricultural respiratory conditions due to organic dust into five basic conditions. These included: 1) acute organic dust toxic syndrome (a common acute flu-like inflammatory condition caused by organic dust and its content of endotoxin), 2) acute hypersensitivity pneumonitis (a rare flu-like condition caused by a cellular immune etiology).  Further the consensus process identified three chronic conditions as part of the organic dust respiratory syndrome:  1) mucous membrane inflammation, 2) bronchitis, and 3) non-allergic (atypical) asthma. The results of this conference established that endotoxin inflammation, not atopic allergy, was the main cause of these conditions. Further, this conference provided a standardized clinical lexicon and treatment methods and environmental assessment methods for endotoxin in organic dust. The results of this workshop advanced this field of study leading the way for new research, treatment and prevention of organic dust respiratory disease.  The proceedings of this landmark workshop were chronicled in in an entire issue of The American Journal of Industrial Medicine (Rylander, Donham, and Peterson 1986).

The success of this conference along with the positive response among the scientific community led to a series of follow-on conferences titled respectively: in 1990, Organic Dusts and Lung Disease, and in 1994, Causative agents for Organic Dust Related Diseases.  All these conferences were held in Skokloster, Sweden, a former monastery for cloistered nuns who made shoes, repurposed as a conference venue.  Thereafter these conferences became known as the Skokloster Organic Dust Conference Series.

Rylander became the primary driver of these conferences. I remained an associate and collaborator with Rylander in the organization and promotion of these conferences. Peter Thorne from our group at the University of Iowa was another regular participant in these conferences. The results of the Skokloster conferences were reported in the Journal of Industrial Medicine (Donham, and Thorne 1994). In summary, the impact of these conferences moved the field of agricultural respiratory diseases research, treatment, and prevention, ahead by as much as a decade.

Advances in Agricultural Medicine Education During the Middle Ages of IAM (1974 – 1985)

This period included a newly designed and developed educational and training program in Agricultural Medicine. We scoured the literature and reviewed offerings at other universities world-wide and could not find any course or program in agricultural medicine. Developing our curriculum in agricultural medicine was de novo. The academic basis of the program was anchored by a new course I developed called Agricultural Medicine and Rural Health.  This course was designed for medical students and Family Practice Residents. It was during this period that we published the first text in agricultural medicine Medical Practice in Rural Communities  (Mutel and Donham, 1983). This book served as a reference for medical students taking the public health (Rural Health segment) course offered to sophomore students.  However, secondary targets were students in other medical schools and their faculty members who would insert course-material on agricultural medicine into their curriculum.

The new course Agricultural Medicine and Rural Health became the foundational component of the larger curriculum, titled the Rural Health and Agricultural Medicine Training Program.  Details of this program are seen in the printed brochure seen as Appendix CStudents targeted for this program included medical students, veterinary students, physician assistant students, and graduate students in Preventive Medicine and Environmental Health. Research opportunities were also available for students in the program either as a requirement for the graduate degree, or just for experience as a part of the non-degree program.  A rotation was also a part of the program, which featured field and clinical studies of actual agricultural injury or illnesses cases. Further, students were involved in our consulting services to regional practicing health care professionals and agricultural businesses with referral if necessary, to the occupational medicine clinic or to industrial hygienists in the DPMEH.

As a component of our program evaluation, we queried those who had completed the program and were now out in rural medical or veterinary practice. We sought to know if they had utilized information and skills from our program in their practices. An example is Elizabeth Loeb MD.  She accompanied me on numerous field investigations to swine AFOs where health of the producer was in question. Through that experience, she not only learned to appreciate the agricultural work environment but also learned to take an occupational history and learned cultural sensitivity. Dr. Loeb has recently retired from a primary care  practice in the Iowa City area.

Facilitating New Organizations

The IAM was the first model for an Agricultural Medicine Institute. The activities and programs previously mentioned, were nationally and internationally known. Therefore, we were sought out to help form new organizations. The staff and faculty of the IAM and later DPMEH worked pro bono with principal faculty and staff from other institutions by modeling, consulting, mentoring, and educating to develop their ideas and bring them to fruition.  The following are examples of agricultural health and safety organizations that the IAM and its faculty assisted in their development.

The Institute of Rural Environmental Health at Colorado State University (1975)

During its 20th anniversary year, the IAM was influential in establishing a “sister” in the Institute for Rural Environmental Health at the College of Veterinary Medicine, Colorado State University.  Similar to the IAM, a W.K. Kellogg Foundation grant was important in this Institute’s founding.  This Institute was established with four sections: Occupational Health and Safety, Epidemiology, Toxicology, and Health Services Administration. Drs. Eldon Savage, John Bagby, John Tessari, and Roy Buchan were critical founding faculty. Faculty members of the IAM (principally Berry and Long) provided essential consulting and collaboration to develop and advance this program. In 2002 it was integrated into a new department, the Department of Environmental and Radiologic Health Sciences (DERHS 2002). This department now houses the High Plains Center for Agricultural Health and Safety, one of 10 agricultural health and safety centers funded by NIOSH.  As of this writing, Steve Reynolds PhD directs this center and is Associate Department Head (DRERHS 2002). Dr. Reynolds was a faculty member in the IAM for several years before leaving for Colorado State. During his tenure at Iowa, Reynolds directed the University of Iowa’s Great Plains Center for Agricultural Health.

The Canadian Center for Health and Safety in Agriculture, College of Medicine, University of Saskatchewan, Saskatoon, Canada (1984 – 1985)

In 1984 and 1985, the IAM hosted Dr. James Dosman MD, pulmonary medicine specialist from the University of Saskatoon in Saskatchewan, Canada.  Having grown up on a farm, Dosman was familiar with agricultural exposures. That background facilitated him in treating farmers and grain handlers with respiratory conditions. He aimed to develop a more focused institute to serve farmers’ health.  Faculty members of IAM, primarily Merchant and Donham, consulted with Dr. Dosman on several occasions over the course of a two-year period.  He stated to me on several occasions “I’m following the Merchant and Donham Model” to build an Agricultural Medicine program at the University of Saskatoon. Using the IAM as a model, Dr. Dosman worked with the University of Saskatoon, the College of Medicine, and the Saskatchewan Lung Association to establish the Centre for Agricultural Medicine at his university (Dosman 1986).  That Center has grown and developed to today’s Canadian Centre for Health and Safety in Agriculture.  Having collaboration and continued contact with Dr. Dosman over the years, I (as would many other of his peers) could arguably entitle him the “father of agricultural medicine in Canada.” Another point of contact with the Dosman and the Canadian Center is Shelley Kirychuk BSN, MS, MBA, PhD, CIH.  Shelley came to the IAM in 1996 to study and research in the graduate program of Agricultural Safety and Health. With Donham as her major advisor, she wrote her MS thesis researching an automatic vegetable oil sprinkling system to control dust in swine buildings. She graduated in the Agricultural Health and Safety Program in DPMEH in 1998. She has been a colleague in many ways since then and currently as of this writing is Associate Professor, Department of Medicine, College of Medicine, Canadian Centre for Health and Safety in Agriculture (Dosman 1986).

Summary of critical advances during the middle ages of IAM (1974 – 1985)

Administrative changes during this period pulled the IAM from an independent research institute to an integrated component of the DPMEH in the College of Medicine. New faculty hires for the IAM allowed the DPMEH to nearly double in the number of its faculty. Dr. Isaacson was the Department Head during this period, taking over from Dr. Long, who then replaced Pete Knapp as IAM Director.  When Dr. Merchant took over as the Director of the IAM during the latter part of this period, the IAM essentially became the Environmental Health Section of the Department of Preventive Medicine and Environmental Health.  Other sections in the Department included Biostatistics and Epidemiology.

A number of important accomplishments occurred during the middle ages of the IAM (1973 – 1985) that establish the IAM as a national and international leader in the field of agricultural health and safety.  These events/activities included the following:

  • Three important conferences/documents occurred during this period that helped to strengthen the IAM as a national and international leader in the field.
    • The National Conference on Agricultural Respiratory Diseases in 1973, sponsored by the Society for Occupational Safety and Health. This conference establishes respiratory diseases as one of the most important occupational health risks in agriculture.
    • The State of-the-Art Report on Occupational Safety and Health in Agricultural in 1974. This report brought to the notice of NIOSH the high level of risk for agricultural workers for occupational illnesses and injuries, where formerly mining had been the main target of attention by NIOSH.
    • The Skokloster (Sweden) Conference Series on organic dust disease in agriculture advanced the field of research in agricultural respiratory diseases.
  • The IAM faculty served as facilitators, models, advocates, and consultants in founding several new agricultural medicine academic and research programs with a public health approach. One of these is the sister Institute at Colorado State University – The Institute for Rural and Environmental Health (now the Department of Environmental and Radiologic Health Sciences), which houses the NIOSH funded High Plains Center Intermountain Center for Agricultural Health. The Canadian Centre for Health and Safety in Agriculture was another organization which was facilitated by the faculty of the IAM.
  • IAM faculty conducted critical foundational research during the middle years that led to the recognition of previously unknown hazards in agriculture environmental and agricultural work. These findings helped further strengthened the reputation of the IAM as an international leader in the field.  These research areas include the following:
    • Studies on the PPB contamination in Michigan agriculture in 1977 revealed to the world the public and environmental health risks to this group of chemicals.
    • Studies on bovine lymphosarcoma virus led to recognizing the importance of this virus as a potential zoonotic risk. The virus apparently can damage the immune system in primates – suggesting a possible human health risk. In addition, we provided evidence that BLV can remain viable in milk but does not survive pasteurization. We provided information to the public that only pasteurized mild should be consumed.
    • Recognition of chronic and acute respiratory hazards from dusts and gases to workers in swine and poultry confinement workers opened the door to international studies in this area.

To: New Directions (1986—2007)


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