Distribution of polycyclic aromatic hydrocarbons and heavy metals in soil following a large tire fire incident: A case study

In October 2019, a fire occurred in a tire-recycling facility in Alytus (Lithuania), where around 5000 t of tires had been stored. Only after 10 days was the fire completely extinguished, and the potential contamination of the surrounding environment has raised a large public concern. With an aim to assess the pollution level and pollutants distribution in the surrounding area, we conducted a study on polycyclic aromatic hydrocarbons (PAHs) and heavy metals. High concentrations of total PAHs were found inside the fire zone (315–5872 ng g⁻¹ dw), whereas those detected in the surrounding soils were significantly lower (1.9–72 ng g⁻¹ dw). Some areas with higher anthropogenic impact were found to contain PAH concentrations as high as 70198 ng g⁻¹ dw. Concentrations of Cr, Zn, Ni, Cu, Pb were in the range of 1.1–93.9; 20.7–227.5; 0.2–35.7; 0.9–21.3; 0.9–102.9 μg g⁻¹, respectively. Zn was the prevailing metal in the fire zone, elevated concentrations of Cr, Ni and Cu were also detected in this area. Principal component analysis (PCA) revealed several locations affected by the fire. The one located the closest to the fire zone was found to be highly contaminated with the heavy metals, just like the whole fire zone. Increase of the carcinogenic risk was observed in the fire zone, but no significant risk was detected in the fire-affected stations. The highest carcinogenic risk was detected in the zones with high anthropogenic loading (traffic and urban activities).