PSIV-12 An assessment of heavy metal exposure via urinalysis in dogs deployed to Maui wildfires.

Abstract Working canines are often tasked with operations in highly contaminated and dangerous environments. In response to wildfires in Lāhainā, Upper Kula, Upper Makawao and Olinda on the island of Maui in August of 2023, the Federal Emergency Management Agency (FEMA) activated more than thirty Human Remains Detection (HRD) canine teams to support efforts to locate and recover victims. These wildfires destroyed more than 2,000 structures and were one of the deadliest U.S. wildfires in at least the past 100 years. Canine teams were drawn from multiple locations across the United States. Known hazards included biologicals (i.e. sewage, human remains), pesticides, fertilizers, propane, by-products of combustion and other reactive materials. The exposure to hazards was complicated by high winds, debris removal and persistent combustion. Decontamination plans for personnel and canines were developed and consistently implemented. Following demobilization, urine samples (free catch) were collected from dogs (n = 10) within 48-72 hours following demobilization and travel back to the continental United States. Urine samples from control dogs (n = 2) were also submitted. Samples were centrifuged before the urinary analysis, and the supernatant was separated and stored at −20 °C until the assays and pH levels were evaluated using urine test strips. Urine heavy metals were assessed using inductively coupled plasma‒mass spectrometry. Statistical analyses were performed using GraphPad Prism version 6.00 (La Jolla, CA, USA) with p < 0.05 considered significant. P values < 0.1 were considered borderline. Urine pH was similar between deployed and controlled dogs (p > 0.05). However, total protein levels were increased in deployed dogs (p = 0.05). No significant changes were noted in urine As, Cu, V, Fe, Ni and Sn levels between control and exposure dogs (p > 0.05, respectively). However, a borderline increase in urine Al, Cd and Cr levels was observed in exposure dogs compared to control dogs (p = 0.06, p=0.06 and p=0.06, respectively). An increase in urine Pb levels were observed in exposure dogs compared to control dogs (p < 0.05). None of the dogs in this study demonstrated clinical signs of disease during or following deployment. There are currently no standards for normal or toxic levels of these heavy metals in dog urine. These data are the first to identify heavy metal contamination in urine of dogs immediately following deployment. More research is needed to identify variation due to accumulation vs elimination and to establish guidelines for preventive and follow up care for dogs deployed into highly contaminated areas.