West LA Times

During fires, chemicals known as polycyclic aromatic hydrocarbons (PAHs) are released, affecting individuals ranging from firefighters to those who grill in their backyards. A few PAHs have been identified as potentially cancer-causing, with only one classified as a carcinogen.

Derek Urwin, an adjunct professor of chemistry at UCLA and a full-time firefighter with the Los Angeles County Fire Department, has focused his research on how PAHs interact with DNA sequences mutated in one-third of all human cancers. His team used molecular simulations to demonstrate that six PAHs have a higher likelihood than the known carcinogen to bind to mutational hotspots in the genome linked to cancer and evade mechanisms for repairing DNA lesions.

Urwin's personal motivation stems from losing his brother Isaac to leukemia at 33. This loss inspired him to pursue a career in science alongside firefighting. He collaborated with Anastassia Alexandrova from UCLA's chemistry department and undergraduate Elise Tran on a study published in the Proceedings of the National Academy of Sciences. The study suggests that some chemical relatives of benzo[a]pyrene (B[a]P), the only PAH classified as a known human carcinogen, may pose greater cancer risks.

The researchers employed computer simulations to examine interactions between 15 PAHs and DNA sequences associated with cancer mutations. Six PAHs showed stronger binding affinities compared to B[a]P and were more likely to avoid detection by DNA repair mechanisms.

The findings could lead to quicker identification of harmful chemicals and inform public policy decisions. "We hope that our strategy can speed up the process of studying these chemicals," said Urwin, highlighting potential improvements in public health policies.

Urwin also serves as chief science advisor for the International Association of Fire Fighters and is part of California's Occupational Safety and Health Standards Board. Alexandrova praised Urwin's dual expertise: "Derek’s work as a firefighter made this research possible."

The investigation began when Urwin noted certain PAHs seemed structurally suited to fit into DNA helices like keys into keyholes. The team's method involves modeling atomic interactions using advanced algebraic techniques, comparing B[a]P with other PAHs regarding their binding strength to cancer-related DNA sequences.

Future research will extend this computational approach to other genetic hotspots related to cancer and additional compounds such as PFAS ("forever chemicals"). Urwin values community-based participatory research, emphasizing collaboration between scientists and those they study for mutual benefit.

"My fellow firefighters have historically been underserved by the scientific community," Urwin stated. "Having my feet in both arenas, I want to bring access to scientists so their research can create a positive impact on health in the fire service community."