Post-wildfire contamination of soils and sediments by polycyclic aromatic hydrocarbons in north-central British Columbia, Canada

Background The Nechako River Basin (NRB) is a large, regulated basin in north-central British Columbia, Canada that has been impacted by numerous landscape disturbances, including severe wildfire 2018. Aims aims of this study were to quantify the post-wildfire temporal and spatial extent contamination polycyclic aromatic hydrocarbons (PAHs) both soils riverine sediments, identify primary sources PAHs watershed. Methods Soil samples collected at burned unburned sites 2018 2020 2021. Sediment three tributaries mainstem (i.e. main channel) from Samples analysed for parent PAHs. Key results PAH concentrations decreased soil 2021 but are not below found samples. Tributary sediment showed higher immediately post-fire relative River, years since, trend reversed. Conclusions persist terrestrial aquatic environments following wildfire, various quality guidelines. primarily derived wildfires, with some mixed downstream sites. Implications Wildfires an important source environmental environments.