Hazardous oxygenated polycyclic aromatic hydrocarbons (OPAHs) originate from combustion (primary sources) or postemission conversion of polycyclic aromatic hydrocarbons (PAHs) (secondary sources). We evaluated the global distribution of up to 15 OPAHs in 195 mineral topsoils from 33 study sites (covering 52° N–47° S, 71° W–118 °E) to identify indications of primary or secondary sources of OPAHs. The sums of the (frequently measured 7 and 15) OPAH concentrations correlated with those of the Σ16EPA-PAHs. The relationship of the Σ16EPA-PAH concentrations with the Σ7OPAH/Σ16EPA-PAH concentration ratios (a measure of the variable OPAH sources) could be described by a power function with a negative exponent <1, leveling off at a Σ16EPA-PAH concentration of approximately 400 ng g^–1. We suggest that below this value, secondary sources contributed more to the OPAH burden in soil than above this value, where primary sources dominated the OPAH mixture. This was supported by a negative correlation of the Σ16EPA-PAH concentrations with the contribution of the more readily biologically produced highly polar OPAHs (log octanol-water partition coefficient <3) to the Σ7OPAH concentrations. We identified mean annual precipitation (Spearman ρ = .33, p < .001, n = 143) and clay concentrations (ρ = .55, p < .001, n = 33) as important drivers of the Σ7OPAH/Σ16EPA-PAH concentration ratios. Our results indicate that at low PAH contamination levels, secondary sources contribute considerably and to a variable extent to total OPAH concentrations, whereas at Σ16EPA-PAH contamination levels >400 ng g^–1, there was a nearly constant Σ7OPAH/Σ16EPA-PAH ratio (0.08 ± 0.005 [SE], n = 80) determined by their combustion sources.

中文翻译：

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矿物表土中含氧多环芳烃的全球分布

有害的含氧多环芳烃 (OPAH) 来自燃烧（主要来源）或多环芳烃 (PAH) 的排放后转化（次要来源）。我们评估了来自 33 个研究地点（覆盖 52° N–47° S、71° W–118 °E）的 195 种矿物表土中多达 15 种 OPAH 的全球分布，以确定 OPAH 主要或次要来源的迹象。（经常测量的 7 和 15）OPAH 浓度的总和与 Σ16EPA-PAH 的浓度相关。Σ16EPA-PAH 浓度与 Σ7OPAH/Σ16EPA-PAH 浓度比（可变 OPAH 源的度量）的关系可以用负指数 <1 的幂函数来描述，在 Σ16EPA-PAH 浓度约为400 纳克克^–1. 我们建议低于此值，次要来源对土壤中 OPAH 负担的贡献大于高于此值，其中主要来源在 OPAH 混合物中占主导地位。Σ16EPA-PAH浓度与更容易生物学生产的高极性OPAH（对数辛醇-水分配系数<3）对Σ7OPAH浓度的贡献呈负相关，这证明了这一点。我们确定了年均降水量（Spearman ρ = .33，p  < .001，n  = 143）和粘土浓度（ρ = .55，p  < .001，n = 33) 作为 Σ7OPAH/Σ16EPA-PAH 浓度比的重要驱动因素。我们的结果表明，在低 PAH 污染水平下，次要来源对总 OPAH 浓度的贡献相当大且程度不同，而在 Σ16EPA-PAH 污染水平 >400 ng g ^{–1 时}，Σ7OPAH/Σ16EPA-PAH 比率几乎保持不变（ 0.08 ± 0.005 [SE], n  = 80) 由它们的燃烧源决定。