Occupational Exposure to RadiationKRWSNCT05380570
Epidemiological Study of Korean Radiation Workers
An observational study of Occupational Exposure to Radiation and Neoplasms, Radiation-Induced, run by Korea Institute of Radiological & Medical Sciences at 1 site in South Korea.
Trial summary
Health risks of radiation exposure in the moderate-to-high dose range have been well established. However, the risk remains unclear at low-dose ranges with protracted low-dose rate exposure, which is typical of occupational exposure. Read more about this study
- Who is it for?
- Ages 16 years and older
- Conditions the study is for
- Occupational Exposure to Radiation, Neoplasms, Radiation-Induced, Leukemia, Radiation-Induced
- What is being tested?
- Occupational radiation exposure
- Type of treatment
- Surgery or procedure
- How many people
- 196,379 participants
- Where
- 1 siteSouth Korea
- Study dates
- 18 Nov 2021to 31 Mar 2031
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 16 years and older
- All sexes
- No healthy volunteers
- Child, Adult, Older adult
Study population: Korean radiation workers in the national dose registry
Who may be able to join
- Korean radiation workers in the national dose registry (except for diagnostic medical radiation workers)
Who cannot join
- Unidentified personal identification numbers
- Foreigner
Trial locations and contacts
1 site in 1 country.
South Korea1 site
Korea Institute of Radiological & Medical Sciences
Seoul, Nowon-gu, 01812
About this study
Official title: Health Effects Associated With Occupational Radiation Exposure Among Korean Radiation Workers (Korean Radiation Workers Study)
Health risks of radiation exposure in the moderate-to-high dose range have been well established. However, the risk remains unclear at low-dose ranges with protracted low-dose rate exposure, which is typical of occupational exposure. The purpose of this study is to construct a cohort of Korean radiation workers and to assess health effects associated with occupational radiation exposure. The study population is expected to be about 190,000 Korean radiation workers who have been registered with the Nuclear Safety and Security Commission since 1984. The national dose registry, the national cancer registry, the national vital statistics registry, and the national health insurance data are collected based on the Nuclear Safety Act. Through the linkage of those collected data, we will evaluate radiation-induced health risks including cancer and non-cancer diseases.
Read the detailed description
The study population of this study is approximately 190000 Korean radiation workers registered with the Nuclear Safety and Security Commission since 1984. Diagnostic medical radiation workers were not included in the study population. The national dose registry, the national cancer registry, the national vital statistics registry, and the national health insurance data for radiation workers are collected retrospectively or prospectively based on the Nuclear Safety Act. Through the linkage of those collected data, we will evaluate radiation-induced health risks including cancer and non-cancer diseases. This data collection will be continued at 5-year intervals to update information on existing study participants and recruit newly hired workers if possible.
Age- and sex-specific standardized incidence and mortality ratios will be calculated for overall comparisons of cancer and non-cancer disease risks with general population. For dose-response assessment, excess relative risk (per Gy) and excess absolute risk (per Gy) will be estimated with adjustments for age and potential confounders, such as lifestyle factors and socioeconomic status.
- Conditions
- Occupational Exposure to Radiation, Neoplasms, Radiation-Induced, Leukemia, Radiation-Induced, Radiation Effects
- Being tested
- Occupational radiation exposure
- Keywords
- Ionizing radiation, Cohort study, Radiation workers, Radiation-Induced diseases
- Medical subject headings
- Neoplasms, Radiation-Induced, Leukemia, Radiation-Induced
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Occupational radiation exposureRadiation
Ionizing radiation in workplaces
| Study group | Role | What they receive |
|---|---|---|
| Korean radiation workers | The study population is Korean radiation workers exposed to ionizing radiation in workplaces. Diagnostic medical radiation workers were not included in the study population. Receives: Radiation: Occupational radiation exposure |
What is being measured
The primary outcome is the main question the study is designed to answer.
Radiation-induced cancer risk
Cancer risk associated with occupational radiation exposure
Measured: year 4
Radiation-induced cancer risk
Cancer risk associated with occupational radiation exposure
Measured: year 9
Secondary outcomes (2)
Radiation-induced non-cancer risk
Non-cancer disease risk associated with occupational radiation exposure
Measured: year 4
Radiation-induced non-cancer risk
Non-cancer disease risk associated with occupational radiation exposure
Measured: year 9
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted19 May 2022
- Study start18 Nov 2021
- Primary completion31 Dec 2022
- Study completion31 Mar 2031 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for Occupational Exposure to RadiationStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 196,379 participants (actual)
Sponsor and investigators
- Lead sponsor
- Korea Institute of Radiological & Medical Sciences
- Sponsor type
- Other government
- Responsible party
- Sponsor
- Investigators
- Songwon Seo, Ph.D., Principal investigator, Korea Institute of Radiological & Medical Sciences
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05380570
- Sponsor's protocol ID
- 50091
- Acronym
- KRWS
- Status last verified
- Mar 2026
- First submitted
- 9 May 2022
- Last updated
- 20 Apr 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Seo S, Lim WY, Lee DN, Kim JU, Cha ES, Bang YJ, Lee WJ, Park S, Jin YW. Assessing the health effects associated with occupational radiation exposure in Korean radiation workers: protocol for a prospective cohort study. BMJ Open. 2018 Mar 30;8(3):e017359. doi: 10.1136/bmjopen-2017-017359.
PubMed 29602835Lee D, Cha ES, Park S, Sung H, Noh E, Jeong H, Jang WI, Seo S. Cohort Profile: The Korean Radiation Workers Study (KRWS). Int J Epidemiol. 2024 Apr 11;53(3):dyae060. doi: 10.1093/ije/dyae060. No abstract available.
PubMed 38628072
Study at a glance
From the registry record, last updated by the sponsor on 20 Apr 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Health Effects Associated With Occupational Radiation Exposure Among Korean Radiation Workers (Korean Radiation Workers Study)
- ClinicalTrials.gov ID
- NCT05380570
- Acronym / sponsor ID
- KRWS / 50091
- Conditions
- Occupational Exposure to Radiation, Neoplasms, Radiation-Induced, Leukemia, Radiation-Induced, Radiation Effects
- Keywords
- Ionizing radiation, Cohort study, Radiation workers, Radiation-Induced diseases
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 196,379 participants (actual)
- Lead sponsor
- Korea Institute of Radiological & Medical SciencesOther government
- Study start
- 18 Nov 2021 (actual)
- Primary completion
- 31 Dec 2022 (actual)
- Study completion
- 31 Mar 2031 (estimated)
- First posted
- 19 May 2022 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Health risks of radiation exposure in the moderate-to-high dose range have been well established. However, the risk remains unclear at low-dose ranges with protracted low-dose rate exposure, which is typical of occupational exposure. The purpose of this study is to construct a cohort of Korean radiation workers and to assess health effects associated with occupational radiation exposure. The study population is expected to be about 190,000 Korean radiation workers who have been registered with the Nuclear Safety and Security Commission since 1984. The national dose registry, the national cancer registry, the national vital statistics registry, and the national health insurance data are collected based on the Nuclear Safety Act. Through the linkage of those collected data, we will evaluate radiation-induced health risks including cancer and non-cancer diseases.
Detailed description
The study population of this study is approximately 190000 Korean radiation workers registered with the Nuclear Safety and Security Commission since 1984. Diagnostic medical radiation workers were not included in the study population. The national dose registry, the national cancer registry, the national vital statistics registry, and the national health insurance data for radiation workers are collected retrospectively or prospectively based on the Nuclear Safety Act. Through the linkage of those collected data, we will evaluate radiation-induced health risks including cancer and non-cancer diseases. This data collection will be continued at 5-year intervals to update information on existing study participants and recruit newly hired workers if possible.
Age- and sex-specific standardized incidence and mortality ratios will be calculated for overall comparisons of cancer and non-cancer disease risks with general population. For dose-response assessment, excess relative risk (per Gy) and excess absolute risk (per Gy) will be estimated with adjustments for age and potential confounders, such as lifestyle factors and socioeconomic status.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Number of arms
- 1
| Arm | Type | Receives |
|---|---|---|
| Korean radiation workers | – | Radiation: Occupational radiation exposureThe study population is Korean radiation workers exposed to ionizing radiation in workplaces. Diagnostic medical radiation workers were not included in the study population. |
Who may qualify
- Ages
- 16 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Child, Adult, Older adult
- Study population
- Korean radiation workers in the national dose registry
Key inclusion criteria (1 listed)
- Korean radiation workers in the national dose registry (except for diagnostic medical radiation workers)
Key exclusion criteria (2 listed)
- Unidentified personal identification numbers
- Foreigner
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Occupational radiation exposureIonizing radiation in workplaces | Radiation | Korean radiation workers |
Primary outcome
Radiation-induced cancer risk
Time frame: year 4
Cancer risk associated with occupational radiation exposure
Radiation-induced cancer risk
Time frame: year 9
Cancer risk associated with occupational radiation exposure
2 secondary outcomes
Radiation-induced non-cancer risk
Time frame: year 4
Radiation-induced non-cancer risk
Time frame: year 9
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 20 Apr 2026.
- Background: PubMed 29602835Seo S, Lim WY, Lee DN, Kim JU, Cha ES, Bang YJ, Lee WJ, Park S, Jin YW. Assessing the health effects associated with occupational radiation exposure in Korean radiation workers: protocol for a prospective cohort study. BMJ Open. 2018 Mar 30;8(3):e017359. doi: 10.1136/bmjopen-2017-017359.
- Results publication: PubMed 38628072Lee D, Cha ES, Park S, Sung H, Noh E, Jeong H, Jang WI, Seo S. Cohort Profile: The Korean Radiation Workers Study (KRWS). Int J Epidemiol. 2024 Apr 11;53(3):dyae060. doi: 10.1093/ije/dyae060. No abstract available.
- Individual participant dataSharing planned: No
Related trials for Occupational Exposure to Radiation
Enrolling by invitation
Personalizing Veterans' Lung Cancer Screening and Diagnosis
Lung Cancer Screening, Military Service-related Environmental and Occupational Exposures
Not yet recruitingObservational study
OCCUPATIONAL NOISE AND CHEMICAL EXPOSURE EFFECTS ON AUDITORY AND VESTIBULAR FUNCTION
Occupational Noise Exposure
Recruiting
Exoskeleton vs. Standard Lead Apron in EVAR Procedures
Radiation Exposure to Operator, Endovascular Aortic Repair
Active, not recruiting
PMT-Based Radiation Safety Training for Nurses: Randomized Controlled Trial.
Occupational Radiation Exposure in Operating Room Nurses
Recruiting
Title: ICARUS - Psycho-physiological Profiling of Low and High Heat-resilient Individuals
Skin Cancer, Heat Tolerance
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Songwon Seo, Ph.D. principal investigator
Korea Institute of Radiological & Medical Sciences
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Occupational Exposure to Radiation and Neoplasms, Radiation-Induced, run by Korea Institute of Radiological & Medical Sciences at 1 site in South Korea.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 1 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: under way, not looking for participants, as of the sponsor's last update on 20 Apr 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in South Korea. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Radiation-induced cancer risk (time frame: year 4). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05380570, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Apr 2026.