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(1) Background: The spontaneous combustion of coal (SCC) not only consumes huge amounts of coal resources but also causes environmental degradation. Rare earth elements (REE) can be taken as an effective indicator to evaluate the environmental effects of SCC. Coal in the Rujigou Mine has been spontaneously combusting for hundreds of years. (2) Methods: The geochemical properties of REE and major elements in the soil of the Rujigou coal mine are methodically examined to reveal the environmental effects of SCC. (3) Results: Soil REE concentration in the Rujigou mine is 216.09 mg/kg, and there is an enrichment of light rare earth elements (LREE) and a depletion of heavy rare earth elements (HREE), LREE/HREE in Rujigou mine was 5.52. The spontaneous combustion of coal could change the vertical distribution of REE, which is conducive to the enrichment of LREE. According to the Eu anomaly and δCe/δEu, the source of material in this mine may be derived from the terrigenous clastic rock controlled by weak reduction. Aluminum and titanium have similar geochemical behavior to REE, especially LREE. The concentration of sulfur is negatively correlated with REE, especially HREE. Calcium, sodium, and magnesium all had a negative correlation with LREE. (4) Conclusions: The spontaneous combustion of coal can lead to the fractionation of light and heavy rare earth elements, resulting in the enrichment of LREE and depletion of HREE. Full article

In this study, the U.S. Environmental Protection Agency prioritized polycyclic aromatic hydrocarbons (PAHs), associated pollution level, and health risks were assessed in a typical coal spontaneous combustion zone in the Rujigou coal mine in Northwestern China. This study used gas chromatography-mass spectrometry (GC-MS) to detect the chemical composition, spatial variation, distribution profiles, impact of coal spontaneous combustion, and health risks of PAHs. The entire study area is divided into three zones according to different features: the spontaneous combustion zone (C-zone), the living zone (L-zone), and the non-spontaneous combustion zone (N-zone). The results showed that: (1) the highest concentrations were measured in the C-zone, and the average concentrations of PAHs in the C-zone, N-zone, and L-zone were 13.28 ng·m⁻³, 9.56 ng·m⁻³, and 7.67 ng·m⁻³, respectively. (2) The PAHs of the study area were mainly composed of three ring to five ring PAHs. (3) EPA positive matrix factorization (PMF) analysis of qualitative source apportionment of PAHs showed that chemical production was the major source of atmospheric PAHs in all three zones, followed by coal combustion. (4) The inhalation of PAHs showed higher potential cancer risk for children than for adults, and the impact of coal combustion in the C-zone was much greater than the other zone. The adverse health impacts associated with PAH exposure indicates the need for mitigation measures of pollution control in this region. Full article