Hydrocarbon markers for assessing the influence of human activities in the tropical semi-arid region (Acaraú River, state of Ceará, Brazil).

Autor: Fernandes GM; Laboratory for Assessment of Organic Contaminants (LACOr), Institute of Marine Sciences, Federal University of Ceará (LABOMAR-UFC), Av. Abolição, 3207-Meireles,CEP: 60165-081, Fortaleza, CE, Brazil. Electronic address: gabimelo@alu.ufc.br., Martins DA; Laboratory for Assessment of Organic Contaminants (LACOr), Institute of Marine Sciences, Federal University of Ceará (LABOMAR-UFC), Av. Abolição, 3207-Meireles,CEP: 60165-081, Fortaleza, CE, Brazil., de Oliveira AHB; Laboratory for Assessment of Organic Contaminants (LACOr), Institute of Marine Sciences, Federal University of Ceará (LABOMAR-UFC), Av. Abolição, 3207-Meireles,CEP: 60165-081, Fortaleza, CE, Brazil; Laboratory for Environmental Studies (LEA), Federal University of Ceará - Analytical Chemistry and Physical Chemistry Department, Campus do Pici s/n, Bloco 938/939, Brazil., de Lima MFB; Laboratory for Assessment of Organic Contaminants (LACOr), Institute of Marine Sciences, Federal University of Ceará (LABOMAR-UFC), Av. Abolição, 3207-Meireles,CEP: 60165-081, Fortaleza, CE, Brazil., Reddy CM; Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA., Nelson RK; Department of Marine Chemistry and Geochemistry, Woods Hole Oceanographic Institution, 266 Woods Hole Road, Woods Hole, MA 02543, USA., Cavalcante RM; Laboratory for Assessment of Organic Contaminants (LACOr), Institute of Marine Sciences, Federal University of Ceará (LABOMAR-UFC), Av. Abolição, 3207-Meireles,CEP: 60165-081, Fortaleza, CE, Brazil.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2023 Dec; Vol. 344, pp. 140227. Date of Electronic Publication: 2023 Sep 25.
DOI: 10.1016/j.chemosphere.2023.140227
Abstrakt: Coastal ecosystems are facing increasing anthropogenic stressors, including rapid urbanization rates and extensive fossil fuel usage. Nevertheless, the distribution of hydrocarbons in the Brazilian semi-arid region remains relatively uncharacterized. In this study, we analyzed ten surface sediment samples (0-2 cm) along the banks of the Acaraú River to assess the chronic contributions of aliphatic and aromatic hydrocarbons. The Acaraú River is a crucial riverine-estuarine area in the semi-arid region of Northeast Brazil. Ultrasound-assisted extraction and gas chromatograph coupled to a mass spectrometer were used to identify target compounds: 45 PAHs, 27 n-alkanes (C 10 -C 38 ), and two isoprenoids. At most stations, the predominant grain size was sand, and the organic carbon content was less than 1%. The total n-alkanes concentration ranged from 14.1 to 170.0 μg g - 1 , while individual pristane and phytane concentrations ranged from not detected (nd) to 0.4 μg g -1 and nd to 0.7 μg g -1 , respectively. These concentrations resemble those found in unpolluted sediments and are lower compared to samples from urbanized coastal areas. The total USEPA PAHs concentration varied from 157.8 to 1364 ng g -1 , leading to the characterization of sediment samples as moderately polluted. Based on diagnostic ratios calculated from both alkane and PAH concentrations, the sediment samples were predominantly deriving from pyrolytic sources, with some contribution from petrogenic sources. The most abundant group was 5-ring PAHs (mean: 47.3 ± 36.7%), followed by 3-ring PAHs (mean: 17.9 ± 13.7%). This predominance indicates a pyrolytic origin of hydrocarbons in the Acaraú River. The concentrations reported here were representative of the level of background hydrocarbons in the region. Regarding the sediment quality assessment, BaP TPE calculated for the Acaraú River ranged from 13.2 to 1258.4 ng g -1 (mean: 409.3 ± 409.4 ng g -1 ). When considering site-specific sediment quality values for the coast of the state of Ceará, half of the stations are classified as strongly contaminated, and toxic effects are expected to occur (SQGq >0.25) for the ∑16 PAHs measured in the samples, especially due to dibenz [a,h]anthracene concentrations.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2023. Published by Elsevier Ltd.)
Databáze: MEDLINE
Externí odkaz: