biostudies-literatureUnknown15(1)Aiello IWFires at lithium-ion battery storage facilities pose emerging environmental risks that remain largely undocumented under real-world conditions. Following a major fire at the world's largest Battery Energy Storage System (BESS) in Moss Landing, California, we conducted rapid, high-resolution soil surveys to quantify metal fallout in adjacent estuarine wetlands. Field-portable X-ray fluorescence (FpXRF), validated by SEM/EDS, laboratory XRF, and ICP-MS, revealed a significant but transient surface enrichment of nickel (Ni), manganese (Mn), and cobalt (Co). This enrichment had Ni: Co mass ratios near 2:1 serving as a geochemical fingerprint of NMC-type cathode materials. The metals were confined to a shallow surface layer (< 5 mm). Surface concentrations declined rapidly following precipitatiScientific reports42113https://www.ebi.ac.uk/biostudies/studies/S-EPMC12658236biostudies-literatureCoastal wetland deposition of cathode metals from the world's largest lithium-ion battery fire.PMC12658236Fountain MKahn ASHeim WCunningham SWasson KAiello IWEndris CGrand MMfalseCoastal wetland deposition of cathode metals from the world's largest lithium-ion battery fire.Fires at lithium-ion battery storage facilities pose emerging environmental risks that remain largely undocumented under real-world conditions. Following a major fire at the world's largest Battery Energy Storage System (BESS) in Moss Landing, California, we conducted rapid, high-resolution soil surveys to quantify metal fallout in adjacent estuarine wetlands. Field-portable X-ray fluorescence (FpXRF), validated by SEM/EDS, laboratory XRF, and ICP-MS, revealed a significant but transient surface enrichment of nickel (Ni), manganese (Mn), and cobalt (Co). This enrichment had Ni: Co mass ratios near 2:1 serving as a geochemical fingerprint of NMC-type cathode materials. The metals were confined to a shallow surface layer (< 5 mm). Surface concentrations declined rapidly following precipitati2025-01-01T00:00:00Z2025 Nov2026-06-06T07:16:22.458Z2026-06-06T03:06:56.197ZS-EPMC126582364129845710.1038/s41598-025-25972-8