Programa de Pós-Graduação em Aquicultura, Universidade Federal do Rio Grande, Laboratório de Piscicultura Estuarina e Marinha, CEP 96201-900, Rio Grande, RS, Brazil.
Sci Total Environ. 2010 Apr 1;408(9):2054-9. doi: 10.1016/j.scitotenv.2010.01.063. Epub 2010 Feb 18.
Accidental discharges and oil spills are frequent around the world. Petroleum-derived hydrocarbons are considered one of the main pollutants of aquatic ecosystem. The importance of petroleum and refined fuels is notorious because today's society depends on them. Researches related to the toxic water-soluble fraction (WSF) of petroleum and derivatives to aquatic biota are scarce. For this reason, deleterious effects of WSF of Brazilian petroleum, automotive diesel and unleaded gasoline to marine pejerrey Odontesthes argentinensis larvae were studied employing toxicity tests and histopathological examination. Each WSF was generated in a laboratory by mixing four parts of seawater with one part of pollutant by approximately 22 h. Larvae were exposed during 96 h to different concentrations of WSF of petroleum, diesel, and gasoline, plus a control. After 96 h of exposure to the different WSFs, three larvae were sampled for histopathological studies. The median lethal concentration after 96 h (LC50) of exposure for WSF of petroleum was equal to 70.68%, it was significantly higher (P<0.05) than the values for WSF of diesel and gasoline, which were 13.46% and 5.48%, respectively. The histological examination of pejerrey larvae exposed to WSF of petroleum, diesel and gasoline after 96 h revealed a variety of lesions in the larvae. The gills, pseudobranchs and esophagus presented epithelial hyperplasia, and the liver presented dilatation of hepatic sinusoids, hepatocitomegaly, bi-nucleated and nuclear degeneration of hepatocytes, such as pyknotic nuclei. The acute toxicity of diesel and gasoline is at least fivefold higher than Brazilian petroleum. However, all toxicants induced histopathological abnormalities in pejerrey larvae. The results are of importance since much attention has been paid to large visible surfaces of petroleum spills instead of potential toxic effects of dissolved aromatic hydrocarbons, which are more available to marine biota.
意外排放和溢油事件在全球范围内频繁发生。石油衍生的碳氢化合物被认为是水生生态系统的主要污染物之一。石油和精炼燃料的重要性是众所周知的，因为当今社会依赖它们。然而，有关石油及其衍生物对水生生物群的有毒水溶性部分（WSF）的研究很少。因此，研究了巴西石油、汽车柴油和无铅汽油的 WSF 对海洋小沙丁鱼 Odontesthes argentinensis 幼虫的毒性作用和组织病理学变化。通过将四份海水与一份污染物混合，在实验室中生成每个 WSF，混合时间约为 22 小时。将幼虫暴露于不同浓度的石油、柴油和汽油 WSF 以及对照中 96 小时。暴露于不同 WSF 96 小时后，从每组中取三个幼虫进行组织病理学研究。石油 WSF 的 96 小时半数致死浓度（LC50）等于 70.68%，明显高于柴油和汽油 WSF 的值（分别为 13.46%和 5.48%）（P<0.05）。暴露于石油、柴油和汽油 WSF 96 小时后，小沙丁鱼幼虫的组织学检查显示幼虫出现多种病变。幼虫的鳃、伪鳃和食管出现上皮细胞增生，肝脏出现肝窦扩张、肝细胞肥大、双核和核变性，如固缩核。柴油和汽油的急性毒性至少比巴西石油高五倍。然而，所有毒物都导致了小沙丁鱼幼虫的组织病理学异常。这些结果很重要，因为人们已经关注到石油溢油的大可见表面，而不是更易被海洋生物群吸收的溶解芳烃的潜在毒性效应。
