In the present study, we applied forensic geochemistry to investigate the origin and fate of spilled oils like tarballs stranded at the beaches of Bahia, in northeastern Brazil, in September 2023, based on their fingerprints. Saturated and aromatic compounds were assessed by gas chromatography, and the oceanic surface circulation patterns were deciphered to determine the geographic origin of the spill. Contamination by petroleum represents an enormous threat to the unique, species-rich ecosystems of the study area. The geochemical fingerprint of the oil spilled in 2023 did not correlate with those of previous events, including the one in 2019, the one in early 2022 in Ceará, and an extensive spill across the Brazilian Northeast in late 2022. However, the fingerprint did correlate with crude oils produced by Middle Eastern countries, most likely Kuwait. The oil of the 2023 spill had a carbonate marine origin from early mature source rocks. These findings, together with the moderate weathering of the 2023 tarballs and the ocean circulation patterns at the time of the event, indicate that the oil was discharged close to the shore of Brazil, to the east or southeast of Salvador, by a tanker on an international route in the South Atlantic.

中文翻译：

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法医地球化学揭示国际船舶倾倒是 2023 年底巴西海岸线（巴伊亚）新石油泄漏的一个来源


在本研究中，我们应用法医地球化学根据指纹，调查了 2023 年 9 月搁浅在巴西东北部巴伊亚海滩的焦油团等泄漏石油的来源和命运。通过气相色谱法评估饱和化合物和芳香化合物，并破译海洋表面环流模式以确定泄漏的地理来源。石油污染对研究区域独特的、物种丰富的生态系统构成了巨大的威胁。 2023 年漏油事件的地球化学指纹与之前事件的地球化学指纹并不相关，包括 2019 年发生的漏油事件、2022 年初塞阿拉发生的漏油事件以及 2022 年底在巴西东北部发生的大规模漏油事件。然而，指纹确实存在相关性。中东国家（最有可能是科威特）生产的原油。 2023 年漏油事件的石油源自早期成熟烃源岩的碳酸盐海洋。这些发现，加上 2023 年焦油球的中度风化以及事件发生时的海洋环流模式，表明这些石油是由一艘油轮在萨尔瓦多东部或东南部的巴西海岸附近排放的。南大西洋国际航线。