Breast cancer cluster suspected at NC State’s Poe Hall, contaminated with PCBs; separate study shows those chemicals linked to that cancer

NC NEWSLINE - A 2020 study of nearly 800 North Carolina women found that PCBs might increase the risk death from breast cancer, raising questions about a suspected cluster at N.C. State’s Poe Hall, which is contaminated with high levels of the toxic chemical. In addition, among women who already have breast cancer, the study found PCBs could contribute to deaths from all causes. PCBs are known to accumulate in breast tissue.

Sampling results from Poe Hall in November showed extremely high levels of PCBs in multiple rooms and in air handling systems, Newsline reported. The university closed the building that month and relocated classrooms and offices, where 100-250 people worked. Meanwhile, university officials were asking the Centers for Disease Control and Prevention to conduct a Health Hazard Evaluation regarding a “breast cancer cluster” there, according to documents obtained by Newsline under the Freedom of Information Act.

Also in communication with the CDC were Assistant General Counsel Leslie Mize, Head of Occupational Medicine Maria Limmen, Director of Environmental Health and Safety Robert Segura, and Senior Industrial Hygienist Ogaga Tebehaevu.

However last month, progress on the evaluation stopped, per N.C. State’s request, WRAL reported, quoting the CDC. University officials told the station the CDC is responsible for halting it.

N.C. State has also tapped its outside lawyer to help the university navigate potential liabilities related to PCB contamination. Todd Roessler, a partner with Kilpatrick Townsend in Raleigh, was copied on several emails and invited to join a video conference about the evaluation. Roessler’s expertise is in environmental litigation and regulatory counseling.

What are PCBs?

Monsanto was the primary manufacturer of PCBs in the U.S. There are 209 PCB mixtures commercially known as Aroclors; in Poe Hall Aroclors 1254 and 1262 were detected, test results showed. (The last two digits indicate the percentage of chlorine by weight. For example, Aroclor 1254 is 54% chlorine by weight.)

Until the mid to late 1970s, PCBs were commonly used in building materials, such as caulking and carpets; flame retardants, fluorescent lighting and electrical systems. While the EPA banned their manufacture in 1979, old buildings such as Poe Hall can still contain PCBs.

They don’t easily break down in the environment and are present in dozens of Superfund sites. PCBs are still found in fish; state health officials have issued fish consumption advisories for PCBs throughout North Carolina, including Lake Crabtree in Raleigh.

How can I be exposed?

Eating fish or other foods that contain PCBs in one way, but so is inhaling or touching contaminated materials.

How can they harm my health?

In addition to being a probable carcinogen, PCBs can also harm the immune, reproductive, respiratory and nervous systems, cause skin lesions, and have been associated with diabetes and liver toxicity.

Tell me about the breast cancer study

Scientists at several universities, including UNC-Chapel Hill, enrolled 456 white and 292 Black women in North Carolina who were diagnosed with invasive breast cancer from 1993 to 1996. Over a median follow-up of 20.6 years, there were 392 deaths — 210 of them from breast cancer.

Here are the major findings:

  • Women with the highest blood levels of certain types of PCBs were at greater risk of dying of breast cancer within five years.
  • Among women with breast cancer who lived longer than five years, higher blood levels of individual types of PCBs were associated with higher death rates from all causes. The total amount of PCBs in the women’s blood also increased their risk of death from all causes by 20% to 37%.

Several types of PCBs posed the greatest risk for breast cancer. These types are the individual PCB compounds, also known as “congeners.” Combinations of these individual PCB compounds, or congeners, make up the mixtures used the various Aroclors. Some Aroclors contain more than 90 congeners.

To use a cooking example, if a Aroclor 1254 were a chocolate chip cookie, the congeners would be the chips, the butter, eggs, sugar, etc. If Aroclor 1260 were an oatmeal raisin cookie, the congeners would be different: oatmeal, raisins, cinnamon, etc.

The congeners associated with higher death rates within five years were PCB 74, PCB 99, and PCB 118, the study found.

Two other types, PCB 183 and PCB 187, also increased the risk of developing breast cancer. By race, PCB 74 was associated with a greater increase in breast cancer deaths among Black women.

A review of scientific literature showed that all the PCB types found in the women with breast cancer are present in some formulations of Aroclor 1254 and 1262, both found in Poe Hall.  However, the amounts in the Aroclor can vary, even by batch.

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