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FAQs: Dose Reconstruction Frequently Asked Questions

Once a claim is filed under The Act, the Department of Labor (DOL) determines if the employee worked at a covered facility during a covered time period and has a qualifying health condition. If the health condition in the claim is cancer, the case is then sent to NIOSH for dose reconstruction. Dose reconstruction is the scientific process of estimating a worker's past exposure to radiation. It uses exposure monitoring and other information to determine what levels of radiation the workers were exposed to while they worked at a facility.

Once the dose reconstruction is completed by NIOSH, the case is returned to DOL. The information from the dose reconstruction is used by DOL to determine the probability that a worker's cancer was "at least as likely as not" due to the employee's occupational exposure to radiation during employment at a covered facility.

To find answers to your questions about Dose Reconstruction, click any one of the questions listed below to view its answer.

Dose Reconstruction

What is dose reconstruction?

Dose reconstruction is the scientific process of estimating a worker's past exposure to radiation. It uses exposure monitoring and other information to determine what levels of radiation the workers were exposed to while they worked at a facility.

What is the purpose of dose reconstruction?

Dose reconstructions are used to estimate the radiation doses to which an individual worker or group of workers have been exposed. The information from the dose reconstruction is used by DOL to determine the probability that a worker's cancer was "at least as likely as not" due to the employee's occupational exposure to radiation during employment at a covered facility.

Who will be assigned to complete the dose reconstruction for my case?

A Health Physicist (HP) will be assigned to complete the dose reconstruction for your case. A HP is an individual with knowledge of the physical, biological, and chemical properties of radiation, radiation producing equipment, and radioactive materials. They are knowledgeable about the measures to protect individuals, the population, and the environment from the potentially harmful health effects of radiation exposure. Health Physicists have technical skills encompassing many disciplines such as: biochemistry, biology, chemistry, ecology, industrial hygiene, mathematics, physics, and toxicology.

Under the NIOSH Dose Reconstruction Program, HPs:

  • Conduct extensive data searches at various Department of Energy sites and federal and private records storage locations throughout the United States to obtain required information
  • Review and analyze work site and employee data
    • Examples of work site data: health physics practices and policies, monitoring practices, operations, production processes, safety procedures, radiological survey data, types and quality of radioactive materials used, incident reports
    • Examples of employee data: internal and external exposure records such as film badge readings, x-rays, urinalysis results
  • Develop and implement dose reconstruction policies, procedures, and guidelines
  • Develop and implement Special Exposure Cohort Evaluation Reports
  • Review and respond to issues identified by the Advisory Board and their contractor
  • Attend/conduct worker outreach meetings (meetings where energy employees can obtain program information and also provide information for consideration and possible use in dose reconstruction)
  • Ensure that Quality Control/Assurance measures are included in the entire dose reconstruction process
  • Interact with the Department of Energy and Department of Labor regarding programmatic and case-specific issues

What if the Health Physicist assigned to complete my dose reconstruction worked at the same facility/facilities that I worked?

We understand your concerns over the possibility of a conflict or bias (COB) the HP may have in completing your dose reconstruction. Each HP that carries out responsibilities for the NIOSH Dose Reconstruction Program must sign a COB Disclosure Form. The form contains a series of questions that helps determine whether a COB may exist arising from a past, current or planned employment-related, financial, familial and/or a supervisory relationship. If a COB exists, the HP cannot complete a dose reconstruction for the site where a conflict or bias exists. Another HP will be assigned to your case.

The Department of Labor (DOL) already has my medical records. Why do you need to request information from the Department of Energy (DOE)?

The information we are requesting from DOE is your exposure monitoring information. In order to conduct the dose reconstruction for your case, we need to identify the levels of radiation to which you were exposed. We may review your medical records while conducting the dose reconstruction; however, your exposure monitoring records will provide us with one source of information we need to conduct our dose reconstruction.

Does NIOSH conduct dose reconstructions for workers who have been diagnosed with illnesses other than cancer?

No. Under Part B of the Act, NIOSH only conducts dose reconstructions on workers who have been diagnosed with cancer.

How can a worker or survivor request an individual dose reconstruction?

Anyone wishing to file a claim will need to complete DOL claims forms. These forms can be found under the Claims Forms section of the DOL EEOICP Website.

DOL will collect medical, employment, and other information from the worker or survivor and make a decision about whether or not he or she qualifies for compensation and benefits.

What is NIOSH doing to help claimants understand the dose reconstruction process?

EEOICPA is a complex program that is based on very complex science, and we recognize that this makes it difficult for claimants to understand the dose reconstruction process. NIOSH provides many sources of information to help claimants understand this process:

  • Claimant Correspondence on the Dose Reconstruction Process

    While a case is at NIOSH for dose reconstruction, claimants and their authorized representatives receive various pieces of correspondence. This correspondence may provide case status, explanations of steps in the dose reconstruction process, dose reconstruction findings, and other helpful program information.

    Additional information on these documents can be found on the Frequently Asked Questions (FAQs) Claimant Correspondence page of our website.

  • Voluntary Phone Call

    Each claimant has the opportunity to participate in the phone call prior to the dose reconstruction process and again when a draft dose reconstruction is prepared. These calls are an opportunity for claimants to provide information and to ask questions about the process.

    Additional information on the phone calls can be found on the Frequently Asked Questions (FAQs) Work History Phone Call and Work History Phone Call Information pages of our website.

  • Supplemental Information NIOSH provides supplemental information in a variety of forms that explain the technical aspects of the program in language and format suitable for a general audience:
    • Easy-to-read fact sheets and brochures
    • Short educational video designed to provide a basic understanding of the program to those who have a claim undergoing dose reconstruction
    • Glossary of terms commonly used in reference to NIOSH dose reconstructions and EEOICPA
    • NIOSH Website which provides comprehensive information about NIOSH's dose reconstructions and other activities in support of the compensation program

    The documents mentioned above can be found on the Publications and Products module located on the DCAS Homepage

  • Additional Support Claimants can also contact NIOSH directly at 513-533-6800 (toll-free at 1-877-222-7570) or by e-mail at or for questions about the dose reconstruction process.

NIOSH is always open to specific suggestions that would help us improve the clarity of our documents and our communication. We continue to strive to assist our claimants, claimant advocates, the public, and media and feedback is greatly appreciated.

What information is needed to conduct a dose reconstruction?

We try to use personal exposure information whenever possible. This would include film badge readings, x-rays, urinalysis results, incident reports, etc. If there is little or no personal exposure information, we use information from technical documents (e.g., Technical Basis Documents, Site Profile documents, Technical Information Bulletins), and coworker data to provide reasonable estimates of dose where the personal exposure information is lacking.

Is there anything I need to send to NIOSH to help with the dose reconstruction?

At the appropriate time, we will contact you to set up a convenient date and time for a voluntary phone call. That's a time we have put in our process to ask you for information we might need. Prior to the phone call, if we need any additional information from you, we will contact you. At any point in the process, you are more than welcome to provide any information which you may feel help your claim.

How will NIOSH complete a dose reconstruction for a case when there is little or no exposure monitoring information available?

If there is little or no personal exposure information, we use information from technical documents (e.g., Technical Basis Documents, Site Profile documents, Technical Information Bulletins), and data from other workers at the site to fill in the areas where the personal exposure information is lacking. The assumptions used in conducting dose reconstructions are designed to give the claimant the benefit of the doubt whenever estimated radiation dose levels are used. Dose reconstruction could require extensive data gathering and analysis. This may include:

  • Determining specific characteristics of the monitoring procedures
  • Identifying events that were unmonitored
  • Identifying the types and quantities of radioactive materials involved
  • Evaluating production processes and safety procedures
  • Identifying the locations and activities of exposed persons
  • Identifying comparable exposure circumstances for which data is available to make assumptions
  • Conducting a variety of complex analyses to understand the data compiled or estimated
  • Utilizing cancer risk models*

    *A cancer risk model is a mathematical model based on the dose-response relationship determined for a given cancer type and is used to estimate the probability of causation (PC) using information on radiation dose and personal data. Cancer risk models and the amount of radiation dose an energy employee was exposed to are the main determinants of probability of causation. The cancer risk models are based on the best science available and the radiation dose levels are based mostly on very generous dose reconstruction methods.

NIOSH may also use the following sources of information:

  • Department of Energy (DOE) and its contractors, including Atomic Weapons Employers (AWEs) and the Former Worker Screening Program
  • NIOSH and other records from health research on DOE worker populations
  • Information shared during phone calls and records provided by the claimant
  • Co-workers of covered employees, or other witnesses with information relevant to the covered employee's exposure identified during a phone call with NIOSH
  • Labor union records from unions representing employees at covered facilities of DOE or AWEs
  • Other relevant information

Why are technical documents sometimes used in completing dose reconstructions?

NIOSH uses technical documents called Site Profiles, Technical Basis Documents, and Technical Information Bulletins as guides and summaries of sites to assist our Health Physicists with conducting dose reconstructions. These documents supplement or fill-in the gaps of information where an energy employee's personal monitoring information is lacking or incomplete. Technical documents provide a way of compiling the large quantity of site data and of providing instructions for preparing dose reconstructions consistently.

Additional information on technical documents used in dose reconstruction can be found on the Frequently Asked Questions (FAQs) Technical Documents page.

What happens if additional site information becomes available after a technical document has been completed?

Our technical documents are considered "living" documents. This means that they are subject to change if relevant information becomes available to warrant that we make a change to a technical document.

If the information has the potential to effect the outcome of previously completed dose reconstructions, a Program Evaluation Report (PER) is used to evaluate the information and determine whether or not dose reconstructions need to be reworked, additional reviews need to be conducted, corrective actions need to be taken, etc.

A PER may be necessary when relevant new information becomes available, when there is a policy change, or when other programmatic changes have the potential to effect previously completed dose reconstructions. As required by our dose reconstruction regulation, any substantial change in our program requires review and re-examination of completed cases to determine if the changes would alter the compensability of the case.

How will a dose reconstruction be done for my case?

NIOSH starts by collecting an initial set of records from DOE and other sources that provide us with information on your radiation exposures. These records may, or may not, include personal monitoring of your radiation doses. In addition, the records might also include area monitoring of radiation levels and process descriptions that help characterize the possible levels of radiation exposures, the use of radiation protection measures, and the occurrence of incidents involving unexpected radiation exposures.

The next step is to schedule a voluntary telephone call with you to try to identify information that may not be found in the records we have collected. After we have collected the information needed, we will perform analysis that allows us to estimate the range of radiation dose you may have been exposed to in your workplace. This range will include the least radiation you might have received and the most -- the "worst case." We will report the estimates of your dose with ranges that include the worst case to DOL.

Before we report these estimates, however, we will send a copy of the dose reconstruction draft report to you. We will review the report with you, explaining in detail what records, information, and criteria were used to produce the estimates found in your dose reconstruction. This review will enable you to help us ensure that we have taken into account all you and others know about your exposures. In addition, the review will also inform you of exactly how we have done our work, so you can consider whether we have fully addressed any concerns you might have.

How will I know when my case is ready for dose reconstruction?

When your case is ready for dose reconstruction, we will send a letter to you that provides information about NIOSH's policy of selecting a Health Physicist (s) to work on a dose reconstruction for a case. (See Conflict of Interest Letter)

Please note that dose reconstructions cannot be started until sufficient exposure information is collected. Once our contractor has received enough information to conduct the dose reconstruction for your case, your case will be assigned to a Health Physicist.

How long does it take to complete a dose reconstruction?

There are many steps necessary to complete each dose reconstruction, and each step varies for each claim. For example, obtaining the information to complete the dose reconstruction estimate may take a significant amount of time depending on the complexity and availability of the data. Therefore, there is no way to predict how long each claim may take to complete the dose reconstruction process.

How many completed dose reconstructions have been sent back to DOL?

For current numbers on cases returned to DOL for a decision, please refer to the NIOSH Website's Claim Information page.

What if I remember additional information that may be important to my dose reconstruction after DOL has made a decision?

If you have additional information about your case after DOL has made a decision, you can contact DOL and provide them with the information. DOL will then decide whether or not your case should be reopened.

What if I disagree with the findings of the dose reconstruction?

We have worked hard to address the concerns of claimants that might lead to disagreement. NIOSH fully involves the claimant in the dose reconstruction process, makes use of relevant information the claimant and others bring to bear, and directly addresses the concerns we know claimants have.

Claimants have the opportunity to participate in a closing phone call with NIOSH to review the dose reconstruction results and the basis on which the results were calculated.

During the phone call, claimants can voice their disagreement with the findings and provide any additional relevant information that may affect the dose reconstruction or indicate that they are in the process of obtaining such information.

In addition, the Advisory Board on Radiation and Worker Health, an independent federal advisory committee representing scientific, medical, and worker perspectives, reviews samples of NIOSH dose reconstructions to help ensure the quality of the program.

Why is the Advisory Board on Radiation and Worker Health reviewing dose reconstructions?

As The Act requires, the Advisory Board, an independent federal advisory committee representing scientific, medical, and worker perspectives, reviews NIOSH dose reconstructions for scientific validity and accuracy.

How does the Advisory Board on Radiation and Worker Health select dose reconstructions to review?

The Advisory Board has established a system to assist them in randomly selecting dose reconstructions for review. The system they are using helps the Advisory Board make sure that the random sample of cases selected for review represents a variety of places of employment and probability of causation values.

Please note: The Advisory Board does not review cases which do not have a final decision from DOL, and they do not handle cases based on appeals of decisions.

How confident are you and can the public be in the fairness of your methods of dose reconstruction and for identifying cancers that were caused by radiation?

The Act recognizes that we will be dealing with uncertainties and limited data. We have used the best that science has to offer to develop the methods and guidelines for dose reconstruction and probability of causation. We are confident these methods and guidelines are very fair to workers.

To the extent that the science and data involve uncertainties, these uncertainties are handled to the advantage rather than to the disadvantage of the claims. To help ensure that the methods and guidelines are as sound as possible, we will also provide opportunity for full review and comment on our work from the public and from the independent Advisory Board on Radiation and Worker Health.

What is the Methods for Radiation Dose Reconstruction rule?

This rule describes the methods that the Department for Health and Human Services/NIOSH will use to conduct a dose reconstruction for your case. The purpose of dose reconstruction is to characterize the occupational radiation environment to which you were exposed.

Where can I find a copy of the Methods for Radiation Dose Reconstruction rule?

You can find a copy of the Final Rule: Methods for Radiation Dose Reconstruction under The Act - 42 CFR 82 on the Dose Reconstruction page of this website.

NIOSH completed my dose reconstruction and DOL calculated the probability of causation for my claim to be less than 50%. As a result, DOL's recommended decision was to deny compensation for my claim. Since that time, I have had two additional cancers. I reported the two additional cancers to DOL and my case was returned to NIOSH for a new dose reconstruction. NIOSH completed the new dose reconstruction using my two additional cancers and when DOL determined my probability of causation, it was again less than 50%. In fact, once the two new cancers were added to my dose reconstruction, the probability of causation percentage calculated by DOL was lower than the value of my first dose reconstruction. How is this possible? Shouldn't the addition of two more cancers increase the probability of causation value?

NIOSH understands this concern. It may seem obvious that when additional cancers are added to a dose reconstruction it would increase the probability that radiation caused the multiple cancers. However, in some cases, the NIOSH dose reconstruction will result in a lower probability of causation when additional cancers are added. An explanation for how and why this can happen is as follows:

Accurately estimating the exposure a worker received while working at a covered facility is a time consuming process. In order to complete dose reconstructions in as timely and efficient a manner as possible, NIOSH may make assumptions on dose estimates that are favorable to the claimant in order to simplify the dose reconstruction process.

For instance, instead of completing a dose reconstruction which precisely estimates the worker's exposure for cases that would most likely result in a probability of causation well below the 50% necessary for the claim to be compensable by DOL, NIOSH will significantly over-estimate the exposure based on the highest levels of exposure observed or possible for the facility. If the claim will not be compensable even when using these significantly over-estimated exposure estimates, then no further refinement to the dose reconstruction is required.

This manner of dose reconstruction is called an "efficiency measure." It allows NIOSH to issue a timely dose reconstruction where attempts to refine the exposure estimate would not result in a compensable claim (i.e., a full dose reconstruction would in all likelihood produce a much lower probability of causation than the over-estimated exposure values used).

Anytime a new cancer(s) is reported to NIOSH by DOL, NIOSH is required to rework the dose reconstruction to include the new cancer(s). If the new cancer(s) creates a potentially compensable case, NIOSH must refine the dose reconstruction using more probable and precise exposure estimates and not the significant over-estimates as mentioned above. These new, more accurate exposure estimates will be lower than the original estimate because we no longer use the assumptions which overestimated the radiation dose for the cancer found in the initial dose reconstruction. The revised radiation dose estimate may result in a probability of causation for the new cancer(s) that is lower than the non-compensable estimate that was obtained for the first cancer using the over-estimated radiation exposure. That is why the addition of a new cancer(s) may result in a probability of causation that is lower than the probability found for the single original cancer. However, this does not always occur when a new cancer(s) is added to a claim and NIOSH has to rework the dose reconstruction. It is possible for additional cancer(s) to produce a full dose reconstruction that will be determined to be compensable by DOL.

The use of "efficiency measures" and procedures for dose reconstructions that NIOSH follows under The Act are described in detail in Final Rule: Methods for Radiation Dose Reconstruction under EEOICPA--42 CFR 82 [ PDF 129 KB (23 pages)].


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