Peggy Sugarman, PhD | SFFCPF Board Director

The San Francisco Firefighters Cancer Prevention Foundation (SFFCPF) is working with top scientists from our most prestigious universities to improve health outcomes for firefighters. Our donors can be proud to see the immense progress that SFFCPF is making towards informing public policy by funding studies that identify occupational exposures and pave the way towards the discovery of potential interventions that can protect, treat, or reverse biological changes.

One such study is a collaborative effort between the SFFCPF and Dr. Mary Johnson. Dr. Johnson and her team, which has since moved to Harvard University, provided the Board with preliminary findings which I summarize here.

One goal of this study is to understand how the human body responds to exposure and whether firefighters have increased changes in their immune system compared to the general population. The researchers worked with SFFCPF to recruit 50 active-duty firefighters to provide blood samples for immunological testing to learn more about the pathways involved in various types of diseases. The researchers conducted three types of analyses on the blood.

First, the researchers explain that changes in our immune system – our DNA and how our genes function – are altered throughout our lifetimes based on such environmental factors as diet, exercise, and chemical exposures. Changes to our gene expression (epigenetics) alter our response to diseases, making us more likely to get sick since our bodies are not fighting off the invading infections or toxins as efficiently as they are designed to function. Mutations in our genes are also linked to certain types of cancer. “Forever chemicals” – commonly known as PFAS – are man-made chemicals typically used to keep things dry or protected from grease. The term is short for “per-and polyfluoroalkyl substances” that replace carbon and some hydrogen molecules with fluorine. These chemical bonds are strong and do not easily break down, hence the term “forever chemicals”.

The researchers analyzed the blood of 50 firefighters and 50 control subjects in various ways to quantify any significant changes in the gene (DNA). A total of 37,258 sites in the genome were tested to identify differences in gene modifications between the control group and the firefighters. Preliminary results indicate that there are significant gene modifications in firefighters compared to the control group.

The researchers then examined the proteins in the blood to identify cardiovascular and inflammation biomarkers. They found that the biological composition of the plasma in firefighters was different than in the control group, with for example, inflammatory proteins typically associated with systolic heart failure, measles, and the common cold.

Additional analyses were conducted looking at the immune cells one at a time through mass spectrometry. In this analysis, they hypothesized that occupational exposures that firefighters experience may cause differences in the types and frequency of the immune cells in the blood, which can indicate some immune dysfunction. They measured the cellular heavy metals using both blood and urinalysis. They found higher levels of manganese correlated with work experience, with the predominant route of exposure for firefighters through inhalation and dermal contact.

To be clear, the researchers are observing changes in the DNA and how these changes may lead to disease. Understanding the effect of these changes and how they relate to disease is the goal. Findings such as these can help to inform the necessary therapies.

Results from this type of study can strengthen arguments for more protection. SFFCPF has been instrumental in working with the San Francisco Fire Department to eliminate turnout gear that contains PFAS to reduce unnecessary exposure to these “forever chemicals.”

Again, these are preliminary results, and we anxiously await the publication of the findings of this important study. If you are a donor, you can be proud that your dollars are furthering the world’s understanding of the effects of exposure to “forever chemicals”and supporting the identification of technologies and therapies that identify the pathways that may lead to disease. If you aren’t a donor, please consider joining us in this ground-breaking work.