Comparing the Toxicity of Water-Soluble Fractions of Biodiesel, Diesel and 5 % Biodiesel/Diesel Blend on Oreochromis niloticus Using Histological Biomarkers

Abstract

This study estimated end compared the potential toxic effects of the water-soluble fractions (WSF) of biodiesel (B100), diesel and the commercial biodiesel (B5) on Oreochromis niloticus. After a 24 h-exposition to WSF-0% (control) and WSF-serial concentrations of 4.6%, 10%, 22%, 46% and 100%, samples of gill and liver of the exposed fishes were fixed in Bouin's solution, processed, stained using hematoxylin/eosin and analyzed by light-microscopy. WSF-hydrocarbons and methanol contents, analyzed by gas chromatography, were checked against the occurrence of abnormal histopathological alterations. These were not found in the control and WSF-4.6% exposed fishes, while exposures to or above 10%-WSF resulted in histopathological alterations whose severity increased in a dose-dependent manner, being higher in fishes exposed to WSF-diesel, or WSF-B5 when compared to biodiesel. These results, which were corroborated by the chemical analyses, highlighted the histological technique as an appropriate diagnostic tool that can be used for the preservation of water bodies' quality.

Chemical exposure hazardous for fish Hyphessobrycon eques through the incorrect release of oil in Amazon region

“…In aquatic environment, this residue can release molecular contaminants, mainly aromatic hydrocarbon, BTEXs (Benzene, Toluene, Ethylbenzene and Xylene), nitrogen and sulfur-linked heterocyclic compounds which through the water-soluble fraction cause toxicity to aquatic organisms [9,10,12,13,24] .…”

“…Thus, both marine and freshwater fish are subject to the toxic effects of FSA from oil products. These compounds dissolved in water are responsible for the risks to the aquatic environment and the organisms affecting homeostatic imbalance, which results in changes in hematological and tissue parameters [11,13,15,18,24 ], may cause stress and later fish mortality.…”

“…These oil derivatives have hydrocarbon compounds linked to others substances as nitrogen and sulfur, being the size of hydrocarbon chain determines their toxicity [6,9,10] . The toxic potential of oil derivatives has direct correlation with its solubility in water, releasing polycyclic hydrocarbon compounds and BTEXs (Benzene, Toluene, Ethylbenzene and Xylene) [11][12][13] . These compounds has potential to cause bioaccumulation in environment providing hazard to the human and animal health.…”