Hidrocarbonetos policíclicos aromáticos biliares: desenvolvimento de método analítico e avaliação ambiental em estuários da costa do nordeste brasileiro

Abstract

Polycyclic aromatic hydrocarbons (PAHs) are toxic organic compounds widely found in aquatic environments, originating from petrogenic and/or pyrogenic sources. The exposure of aquatic biota to these compounds, especially demersal fish such as catfish of the species Cathorops spixii and Sciades spp., causes significant health impacts due to their carcinogenic potential and physiological alterations. This study aims to assess environmental contamination using OH-PAHs in biomonitors from oiled areas along the northeastern Brazilian coast, as well as to evaluate the effects of this exposure on health indices and fatty acid composition in fish muscle. The analytical methodology employed was high-performance liquid chromatography with fluorescence detection (HPLC-F) for the determination of biliary OH-PAHs. This method analyzed six compounds eluted in the following order: 1-hydroxynaphthalene (1-OHNaph) > 9-hydroxyfluorene (9-OHFln) > 9-hydroxyphenanthrene (9-OHPhen) > 1-hydroxypyrene (1-OHPyr) > 1-hydroxychrysene (1-OHChr) > 7-hydroxybenzo(a)pyrene (7-OHBaP). The most favorable results were obtained using matrix-matched calibration curves, with a linear correlation coefficient greater than 0.98, detection limits (LOD) ranging from 0.03 to 79.2 ng/L, quantification limits (LOQ) from 0.1 to 264.1ng/L, accuracy between 86% and 96%, and relative standard deviation (RSD) between 0 and 8%. In parallel, fatty acids in muscle tissue were determined by gas chromatography with flame ionization detection (GC-FID), and the hepatosomatic (HSI), gonadosomatic (GSI), and gastrosomatic (GaSI) indices, along with Fulton’s condition factor (K), were calculated to assess the physiological status of the individuals. The results revealed high concentrations of low molecular weight (LMW) OH-PAHs in catfish bile, particularly in estuaries such as the Cocó River (CE) with 14.5x104 ng/L (1-OHNaph) and 42.2x104 ng/L (9-OHPhen), the Paraíba River (PB) with 4.8x104 ng/L (1-OHNaph) and 0.2x104 ng/L (9-OHPhen), and the Manguaba River (AL) with 1.77x104 ng/L (1-OHNaph) and 0.82x104 ng/L (9-OHPhen). The fish health indices showed average values ranging from 0.1% to 7.2%, and total fatty acid content ranged from 9383 to 1693 μg/g. Integrated analysis revealed that areas with higher exposure levels also exhibited reduced health indices and altered fatty acid composition, notably a decrease in polyunsaturated fatty acids (PUFAs). Thus, we suggest that OH-PAHs are effective biomarkers for studying environmental exposure to petroleum, and their association with health and biochemical indices provides a robust assessment. The findings of this thesis reinforce the need for continuous monitoring in estuarine areas under anthropogenic pressure, contributing to environmental management strategies and public policies aimed at protecting aquatic biota and ensuring food safety.