Data from: Urban conflagrations: Effects of residential structural ash on soil metal(loid) contamination from California’s Eaton and Palisades Fires

In weeks following the Eaton and Palisades fires in California, structural ash of burned homes, along with soils from yards and curbsides were sampled for analysis of Pb, As, and eight metals from 32 residential properties inside and outside fire perimeters. About six months after fires and after US Army Corps of Engineers (USACE) had completed Phase 2 cleanups that scraped 15-cm soil from the structural ash footprint, 17 of these properties were resampled within about a meter of the original sampling sites. Concentrations of metal(oid)s in structural ash and soil in yards and at curbsides varied between and within properties with significant spatial and temporal patterns. Lead concentrations were highest in structural ash and soil of yards of some pre-1970s homes. About 28% of structural-ash samples exceeded 200 ppm, the residential soil-Pb screening level of the US Environmental Protection Agency (EPA), and 50% exceeded 80 ppm, California EPA’s Pb screening level. After Phase-2 cleanup by USACE, <5% of the samples from within the scraped foundation areas exceeded 200 ppm Pb and 24% exceeded 80 ppm. Fires released metals from some older homes to residential soils in concentrations comparable to those found in unburned city soils in the USA.