- Severance Hospital Intern
- Gangnam Severance Hospital resident
- Occupational and Environmental Medicine Residency, Yonsei University Graduate School of Public Health
- Research Fellow, Occupational Safety and Health Research Institute
- National Cancer Institute Postdoctoral Fellow
- National Cancer Center Senior Researcher
- Department of Occupational and Environmental Medicine, Catholic Kwandong University International St. Mary's Hospital
- Professor at Catholic Kwandong University International St. Mary's Hospital
