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Frequently Asked Questions

1. How do I know whether I’ve been exposed to PBB?

Due to the PBB contamination incident in 1973, people throughout Michigan were exposed to PBB by eating contaminated food. Because PBB stays in the body for a long time, the children of women who ate contaminated food may have been exposed in the womb and through breastfeeding.  

You may have been exposed to PBB if you or your mother:


2. What is the Michigan PBB Registry and how do I know whether I belong to the original Registry? How do I continue to be included?

In 1976, the Michigan Department of Community Health (MDCH, formerly the Michigan Department of Public Health) enrolled approximately 4,000 farmers, chemical workers, and others with PBB exposure risk to participate in the Michigan Long-Term PBB Study. This is now referred to as the Michigan PBB Registry. All original study participants and their children and grandchildren are considered to be members of the registry.

If you or a parent/grandparent were a part of the original Michigan Long-term PBB Study conducted by the state, you may be a part of the original PBB Registry. To find out, please call us at: 1-888-892-0074.

In 2011, MDCH was no longer able to maintain the registry and transferred it to Emory University. However, individuals who want to stay in the PBB registry, must provide consent to transfer their PBB records from MDCH to Emory University. By transferring your health records to Emory University, you will receive up-to-date information on study findings and will have opportunities to guide future research priorities. To transfer your records, fill out the Consent to Transfer Records Form and include the following information at the bottom of the form:

If you are unsure of your family's participation, it is best to list family members. This could help us find your records.

3. How do I know whether I have PBB in my body?

Most people in the United States have a very small amount of PBB in their blood, averaging about 0.015 parts per billion (National Health and Nutrition Survey, 2003-2004). However, those who were exposed to PBB because of the mix-up in Michigan, may have higher levels in their blood. To learn the meaning of the PBB levels, see Question 4.

To detect the level of PBB in the body, blood is drawn and analyzed. However, blood testing for PBB is not a routine test that is available at doctor’s offices and is not a standard laboratory procedure. For those that participated in the PBB research in the last few years, blood was analyzed in a research laboratory at Emory University. The Michigan PBB Registry team, along with local partners, are working to obtain funding to provide more Michigan residents with the opportunity to have their blood levels measured and to participate in PBB health research.

4. What do the PBB levels mean?

60% of Michiganders recently tested have PBB levels above the US population 95th percentile. In 2003-2004, as part of the National Health and Nutrition Examination Survey, the CDC tested blood samples for PBB 153, but have not tested for PBB in more recent surveys.

Click Here to view the distribution of PBB levels in mi registry participants

PBB levels are reported in parts per billion (ppb). Among Michiganders that we have tested in the past three years, the average blood level is 0.17 parts per billion. Although a part per billion is a very low concentration, it’s important to understand that our natural hormones exert their effects at similar low concentrations:

Recent PBB testing reflects the use of new analytical methods, which are able to detect a lower concentration of PBB than previous methods and is also more accurate.  In addition, there are several different forms of PBB. The Firemaster mixture was mostly PBB-153. Measurements from 1990 to the present are reported as the concentration of PBB-153 detected in the blood. Previous PBB measurements were based on different mixtures of PBB types, and are not directly comparable to each other or to the PBB-153 measurements. Because of the advances in laboratory science, the most recent measurements are the most accurate.

5. Can I have my blood tested for PBB?

Blood testing for PBB is not a routine test that is available at doctor’s offices and is not a standard laboratory procedure. The Michigan PBB Registry Team conducts research studies to investigate the health effects of PBB exposure and as part of the research, participants’ blood is tested for PBB. The team has recently completed data collection for the current study. The Michigan PBB Registry team, along with local partners, are working to obtain funding to provide more Michigan residents with the opportunity to have their blood levels measured and to participate in PBB health research. If you are interested in participating in future research studies, please complete the PBB Health Research Interest Form

6. Can my family members or others who ate contaminated food join the PBB registry now?

If you or your parent/grandparent were a part of the original registry, you may join the registry by providing consent to transfer your PBB records from MDCH to Emory University. To transfer your records, fill out the Consent to Transfer Records Form and include the following information at the bottom of the form:

If you are unsure of your family's participation, it is best to list family members. This could help us find your records.

The Michigan PBB Registry team, along with local partners, are working to obtain funding to provide more Michigan residents with the opportunity to participate in PBB health research. To contribute, please visit the Giving tab and learn more about how you can make a difference in the research.

7. Does PBB leave the body after exposure?

Yes, gradually. On average, it takes about 15 years for half of the PBB in the body to be eliminated.  There is currently no medical treatment that will lower PBB levels in the human body.

8. Is there any information about PBB that I could share with my doctor?

A physician’s information sheet is available for download. Please feel free to share this with your doctor: Physician’s Information Sheet

9. I am (or think I might be) part of the PBB Registry. Why should I continue to participate in the Registry?

Some of the health effects of the PBB exposure may take many years to develop and will only be found by continued research. The study findings can help you and your doctor decide if you need more frequent tests for certain conditions. Our research has shown health effects among the sons and daughters of women who ate contaminated food. It is important to continue to study the health of these children as they grow up and have children of their own.

10. How can I participate in the research?

The Michigan PBB Registry team, along with local partners, are working to obtain funding to provide more Michigan residents with the opportunity to have their blood levels measured and to participate in PBB health research. If you are interested in participating in future research studies, please complete the PBB Health Research Interest Form. If you think you, your parents, or grandparents may have been a part of the original PBB Registry, please contact us at 1-800-892-0074 or email pbbregistry@emory.edu.

11. How else can I be involved?

Our website and facebook page are frequently updated with details on future activities, community meetings, and research findings. During community meetings, we discuss research findings and solicit input on future research priorities. To receive information about community meetings and research participation, call or email us to ensure that your email and mailing address are updated.

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