Skip to Main Content


A cardiologist follows a career in corporate medicine, keeping workers healthy

Yale Medicine Magazine, 2010 - Autumn


When Clarion E. Johnson, M.D. ’76, began his career as associate medical director at what was then Mobil Corporation in 1988, he was looking for a 9-to-5 job. Today, as ExxonMobil’s global medical director of the Medicine and Occupational Health Department, he is seldom at home for more than three months at a time.

Although Johnson, a cardiologist, had never considered a career in corporate medicine, “it was a family decision,” he said of his choice. His wife, Heather Mitchell Johnson, M.D. ’79, was working in an ob/gyn practice she really enjoyed. “We knew she would be on call a lot. We had two small children, and it was important to us to have one parent at home. I moonlighted as a cardiologist for a local HMO when my wife was not on call, and I immersed myself in enjoying my children’s lives.”

In 1998, when his children were in their teens, Johnson became Mobil’s global medical director. After Mobil and Exxon merged, he assumed the global position responsible for the health care of 80,000 employees and affiliate employees worldwide. He directs the company’s traditional health care services, including environmental noise, chemical exposure, emergency response support, industrial hygiene, health promotion services, and travel medicine. “A very important facet of my job is to give a real-time assessment of the status of the health infrastructure of a country or location where our employees are working and residing,” explained Johnson.

Johnson and his multidisciplinary team conduct health care briefings with employees who will be working in challenging environments outside the United States, visit sites in 201 countries, confer with the world’s health ministers and practitioners, make rounds in hospitals around the globe, and evaluate employees’ health and well-being once they return to the United States. Johnson’s goal is to communicate a clear and consistent assessment of health care conditions, whether he is meeting with local clinicians, government officials, employees, or their families. “My assessments enable me to determine what the trigger is to evacuate personnel from any location,” he said.

Johnson also assisted with the design and review of a 2008 study comparing ExxonMobil employees’ death records to those of the general population. The results suggest that the company’s U.S. employees are healthier than the population at large. Their rates of death from heart disease and accidents are more than 30 percent lower. This is due in part to the healthy worker effect—people who have jobs are usually healthier than the general population. “Exxon’s commitment to safety and health also is a contributing factor,” said Johnson. “The focus of this study, which is the largest of its kind for the petroleum industry, is on educating the employee population to encourage a sense of control over health.”

Johnson attributes his emphasis on education to his mother, a schoolteacher, and his father, who owned a shoe repair shop in Queens. In the 1950s, his mother, concerned about the quality of public schools in Brooklyn, converted to Catholicism so he could attend a parochial school in the neighborhood. She often took him on tours of Manhattan, specifically to areas where there were racial barriers. “My mother wanted me to understand that most of life’s barriers are manmade and can be overcome,” remembered Johnson. “She could have tea with the Queen of England and feel very comfortable,” he proudly noted.

After high school, Johnson headed to Sarah Lawrence College with the help of scholarships and several work-study programs. “I manned the college’s main reception desk for 12-hour shifts on weekend nights, ran the campus linen service two nights a week, and served as student body president my senior year,” said Johnson, who joined the college’s board of directors two years ago.

The liberal arts curriculum at Sarah Lawrence influenced Johnson’s decision to attend Yale School of Medicine. “I wanted to attend a medical school where I felt there were more students with a liberal arts background like myself,” Johnson said. “I saw more students with b.a. degrees listed at the back of the Yale School of Medicine catalog than at other medical schools.”

Johnson completed his internal medicine residency at Harlem Hospital Center in New York City and a cardiology fellowship at Walter Reed Army Medical Center. Following a military medical science fellowship at Walter Reed Army Institute of Research, he spent two years as a postdoctoral student doing microwave research. He was the director of the Critical Care Support Laboratory and assistant professor at Howard University School of Medicine, and also served as the senior medical officer and researcher at Evaluation Research Corporation International, a contracting agency in Fairfax, Va., that provides scientists and technical support for government projects. For close to three decades, Johnson has been on staff at Fairfax Hospital and an assistant professor at the Uniformed Services University of the Health Sciences in Bethesda, Md. Johnson also sits on the Milbank Memorial Fund board of directors.