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Who We Are:

The Building Trades National Medical Screening Program (BTMed) is administered by CPWR – The Center for Construction Research and Training, the health and safety research center of North America’s Building Trades Unions, in partnership with Stoneturn Consultants, Duke University Medical Center, University of Maryland Medical Center, and Zenith-American Solutions. BTMed is funded by a cooperative agreement from the Department of Energy.


Toll-Free Number: 1-800-866-9663 / 1-888-464-0009

What we do:

The Building Trades National Medical Screening Program (BTMed) provides free, ongoing medical screening services to construction workers previously employed at thirty-five (35) U.S. Department of Energy (DOE) nuclear weapons sites. Over its quarter-century of work, BTMed has completed 46,000 screening exams, as well as 10,000 CT scans for early detection of lung cancer. These exams are provided by over 200 medical clinics across the country. 

Construction workers have been exposed to toxic substances and hazardous conditions, increasing their risk for occupational illnesses. The screenings—which workers are eligible for every three years—help identify work-related health conditions at an early, more treatable stage and contribute to these workers’ overall health and well-being. BTMed has saved lives, helped workers and their families with compensation, and demonstrated to DOE that construction workers need better safety and health protections. The program is well appreciated by its participants and currently records a perfect 100% satisfaction rating.

BTMed Covered Sites
BTMed covers former construction workers from 35 Department of Energy
sites across the country.

Reaching Workers
This year BTMed staff remained busy enrolling new participants and engaging existing ones. Highlights from the past year include:  

  • Participation in 60 in-person events—building trades meetings, retiree meetings, and community fairs. 
  • A visit to the Portsmouth Gaseous Diffusion Plant to meet with workers and distribute BTMed materials—all to boost awareness of the benefits of participating. 
  • An appearance on a local news channel at the DOL/DOE-sponsored meeting in Richland, Washington. 
  • BTMed hosted its second webinar in the DOE Former Workers webinar series.  More than 300 people attended a presentation on hearing loss given by Dr. Marianne Cloeren, BTMed Medical Director. The presentation placed a special emphasis on hearing loss prevention and the importance of taking protective measures to safeguard one’s hearing.  The session also tackled the complicated issue of compensation and the guidelines for filing a hearing loss claim.

What we have found:

Important Occupational Health Findings

a.  Conventional Medical Screening Exams

  • Chest x-rays (N=24,106, participants receiving at least one CXR):  19.2 percent of 24,106 participants demonstrated findings consistent with work-related lung disease 
  • Pulmonary function tests (N=23,690 participants receiving at least one PFT):  22.9 percent of 23,690 participants demonstrated findings consistent with obstructive disease 
  • Beryllium Lymphocyte Proliferation Tests (BeLPT) (N=22,832 participants receiving at least one BeLPT):  2.1 percent of 22,832 participants had at least one abnormal BeLPT 
  • Audiometry (N=22,183 participants receiving at least one audiogram):  67.3 percent of 22,183 participants demonstrated hearing loss for normal speech tones.

b.  Early Lung Cancer Detection Program Exams

Former DOE construction workers at high risk for lung cancer may be eligible for BTMed’s Early Lung Cancer Detection (ELCD) Program. BTMed uses low-dose CT scans to detect lung cancer at an earlier, more treatable stage. BTMed partners with 11 CT scan providers to carry-out these services. Providers are located in Augusta, GA; Cincinnati, OH; Columbia, SC; Denver, CO; Hanford, WA; Idaho Falls, ID; Kansas City, MO; Oak Ridge, TN; Paducah, KY; Portsmouth, OH; and Seattle, WA. 

  • 54 ELCD program participants have been diagnosed with primary lung cancer.
  • 42 of the 54 (77.8 percent) individuals whose lung cancers have been staged to date had an early-stage lung cancer (carcinoma in situ, Stage I or Stage II non-small cell cancer. or limited small cell cancer) at the time of diagnosis.
  • Lung cancer was detected in 54 of 1,941 DOE workers tested.

BTMed and Research:

Using Research to Improve Health. This year, our researchers published two peer-reviewed journal articles based on BTMed participants’ data in the American Journal of Industrial Medicine:
How much have adverse occupational health outcomes among construction workers improved over time? Evidence from 25 years of medical screening. BTMed researchers examined how health outcomes for construction workers have changed over the past 60 years. They found that stronger occupational health protections have had a significant impact, as shown by the reduced risk of occupational disease over that period. The greatest reductions came when there were strong regulatory and legal incentives to reduce exposures, such as illnesses associated with asbestos, silica, and vapors, gases, dusts, and fumes. The smallest improvement was for hearing impairment, where there has been little regulatory enforcement.

Restrictive spirometry pattern (RSP) among construction trade workers. RSP, or low total lung volume, is relatively common in the general U.S. population but has not been associated with workplace exposures. BTMed researchers have previously documented that construction workers are exposed to many substances that cause scarring of the lungs or have other effects associated with RSP. This research found that RSP was significantly associated with most construction trades, even after adjustment for other known risk factors for restrictive lung disease, such as obesity, smoking, hypertension, diabetes, and cardiovascular disease. Because individuals with RSP are likely to die prematurely from respiratory diseases, cardiovascular diseases, and lung cancer, medical professionals should pay more attention to RSP.

Visit to read the full papers. BTMed has completed and published twenty-two (22) studies in scientific literature.

BTMed Medical Team:

Knut Ringen, DrPH, MHA, MPH Principal Investigator, BTMed

Knut Ringen, DrPH, MHA, MPH
Principal Investigator, BTMed

With more than 50 years of experience in public health administration, Dr. Knut Ringen is considered one of the founders of the field of occupational high-risk management. He is an expert in construction safety and health. In 1996, he established the first medical screening program for former DOE construction workers, which evolved into the BTMed ( 

In 1979, Dr. Ringen launched three projects to demonstrate that medical screenings for workers, known to have been exposed to work-related health hazards, could identify occupational illnesses, and could help these workers secure their rights and prevent a premature death. When growing evidence from scientific studies and concerns expressed by workers suggested that DOE working conditions were hazardous, Dr. Ringen advocated for a special focus on construction workers, as these workers were usually employed by subcontractors and were more likely to be assigned the most hazardous duties. Using the data collected from these medical screenings, Dr. Ringen and others have showed how effective this model of medical screening and assistance was and why it should be applied to construction workers on DOE sites. This scientific analysis helped encourage Congress to enact legislation in 1993 that forms the basis for DOE’s Former Worker Medical Screening Program. 

Dr. Ringen was the first executive director of CPWR and currently is its senior science advisor. He has directed other non-profit health organizations and has worked at the National Academy of Sciences and the National Cancer Institute. Among many honors, he is a fellow of the European Academy of Sciences and the Collegium Ramazzini, the international society of scholars in environmental and occupational health. He holds a Master in Hospital Administration from the Medical College of Virginia (now a part of Virginia Commonwealth University) and a Doctor of Public Health from Johns Hopkins University.

Marianne Cloeren, MD, MPH, FACOEM, FACP, Co-Medical Director, BTMed

Marianne Cloeren, MD, MPH, FACOEM, FACP, Co-Medical Director, BTMed

Dr. Marianne Cloeren has decades of experience managing teams of clinicians, serving as Medical Director for a variety of private and government programs. Her work experience includes interacting with remote nurse case managers, managing quality assurance and audits, and delivering effective and well-reasoned case reviews in a federal program. She has written and overseen the production of tens of thousands of such reviews. 

Sammy Almashat

Sammy Almashat, MD, MPH, Co-Medical Director, BTMed

Dr. Almashat is trained in both Preventive Medicine and Occupational Medicine, with a background in public health advocacy. His work experience includes clinical occupational medicine and advocacy work with Public Citizen, including research to support establishing occupational beryllium rules. 

Melissa McDiarmid, MD, MPH, Senior Medical Advisor, BTMed

Melissa McDiarmid, MD, MPH, Senior Medical Advisor, BTMed

Dr. Melissa McDiarmid is a clinical toxicologist who is board-certified in Internal Medicine and Occupational Medicine; she heads the University of Maryland Division of Occupational and Environmental Medicine. A seasoned clinician and researcher, she is an expert in medical surveillance programs and cancer related to occupational exposures. 

William Grier, MD, Senior Medical Advisor, BTMed

William Grier, MD, Senior Medical Advisor, BTMed 

Dr. Grier is an academic pulmonologist with clinical and research interests focusing on increasing enrollment in lung cancer screening, improving rates of follow-up Low Dose CTs, pulmonary nodules, and impact of exposure history on lung cancer. His research includes work on mesothelioma and military exposure risks.