Emerging and Traditional Organic Markers in Areas with Multiple Anthropogenic Activities: Development of an Analytical Protocol and Its Application in Environmental Assessment Studies

Elucidating mechanisms of action of environmental contaminants from Doce River in Brazilian fish embryos using metabolomics and chemometric methods

Mining and other essential economic activities have a long historical contamination impact on diverse aquatic environments, such as the Doce River Basin (DRB), in Southeast Brazil. High concentrations of metals combined with organic chemicals released from multiple sources of contaminants may trigger complex toxicity pathways that are complicated to interpret and distinguish. This study aimed to investigate mechanisms of toxicity of environmental chemicals from DRB using a comprehensive untargeted LC-HRMS metabolomics approach (data-independent acquisition of all ion-fragmentation mode), in fish embryos (Rhamdia quelen) exposed to complex chemical mixtures. The Regions of Interest (ROI) Multivariate Curve Resolution (MCR) approach was applied to compress and resolve data-independent acquisition (DIA) LC-MS/MS complex datasets mode. Fish embryos exposed for 96 h to 6 treatment sample groups showed a distinct pattern of responses when compared to controls, with downregulated essential metabolites, such as amino acids, as a main response, especially for metal exposure. Organic contaminants extracted from sediments combined with inorganic elements have shown non-additive effects, with inorganics possibly exerting greater influence on metabolic responses. The results helped to investigate and distinguish the effects of different complex mixtures of environmental chemicals on fish embryo samples. ROIMCR approach is shown to be a suitable strategy for the analysis of large metabolomics-derived data in the investigation of the effects of different classes of environmental chemicals on aquatic biota and ecosystems.

Unraveling the differences between pyrolytic and petrogenic sources in oiled areas of the South Atlantic: An analytical method for biliary PAHs

Polycyclic aromatic hydrocarbons (PAHs) represent significant organic pollutants within the scope of environmental monitoring and management investigations of oiled areas. Characterized as precursors of mutagenic and carcinogenic processes, they exert a direct influence on human and environmental health. To assess the impacts of one of the largest oil spills affecting coral reefs in Alagoas, Brazil, researchers developed, validated, and applied an innovative methodology. This approach was designed to evaluate the effects of petrogenic and pyrogenic PAHs using Stegastes fuscus, a fish species commonly found in the region. This approach utilizes high-performance liquid chromatography paired with a fluorescence detector (HPLC-FD) to accurately measure PAHs in fish bile. This method analyzed six compounds whose elution occurred in the following sequence: OHNaph > OHFln > OHPhen > OHPyr > OHChr > OHBaP. The most favorable results were observed using the matrix curve, with a linear correlation coefficient exceeding 0.9800, DL ranging from 0.03 to 79.2 ng/L, QL ranging from 0.1 to 264.1 ng/L, and accuracy ranging from 86% to 96% and with RSD between 0 and 8%. To implement the methodology, specimens of the S. fuscus species were utilized, within which all target compounds were detected across all bile samples. In 2020, the compound OHNaph with minimum, maximum value of ND-21.42x104 ng/L, and average 430.65x103 ng/L, was the most frequently detected in the Japaratinga region, while in 2021, OHPyr with ND-20.57x103 ng/L, and 19.99x103 ng/L was the most prevalent, also in Japaratinga. However, the results indicate a consistent decrease in OHNaph concentrations across all sites from 2020 to 2021, whereas levels of OHBaP showed an increase during the same period. The relative abundance of bile PAHs showed that the levels of OHNaph represent the influence of the 2019 oil spill, while the sum of OH PAHs (phenanthrene, pyrene, chrysene, and fluorene) indicates a mixed-source group. Additionally, BaP reflects the impact of chronic sources in the region, allowing for the differentiation between the influence of chronic activities and the acute impact promoted by the 2019 oil spill in the area.

Concentrations, sources and risks of polycyclic aromatic hydrocarbons in sediments from the Parnaiba Delta basin, Northeast Brazil

The Parnaíba River is the main river in the Parnaíba Delta basin, the largest delta in the Americas. About 18 polycyclic aromatic hydrocarbons (PAHs) were identified and the environmental risk associated with the sediments was evaluated. The study found that PAHs levels ranged from 5.92 to 1521.17 ng g-1, which was classified as low to high pollution, and that there were multiple sources of pollution along the river, with pyrolytic sources predominating, mainly from urban activity such as trucking, although the influence of rural activity cannot be ruled out. PAHs correlated with black carbon and organic matter and showed high correlation with acenaphthylene, phenanthrene, pyrene, benzo(a)anthracene, chrysene, benzo(ghi)perylene, and ∑PAHs. The benzo(a)pyrene levels were classified as a risk to aquatic life because the threshold effect level and the probable effect level were exceeded. In addition, the sediments were classified as slightly contaminated with a benzo(a)pyrene toxicity equivalent value of 108.43 ng g-1. Thus, the priority level PAH exhibited carcinogenic and mutagenic activity that posed a potential risk to human health.

An integrated assessment to reconstruct the history of changes influenced by multiple anthropogenic activities (City of Fortaleza, Ceará, Brazil)

In this study, the multi-marker approach was used for the first time with a highly urbanized lake located in the city of Fortaleza, Brazil, to provide a comprehensive view of temporal trends in sources of pollutants and evaluate the relation between the influence of anthropogenic activities and socioeconomic development. Total concentrations of the markers analyzed ranged from 21.0 to 103.8 ng g^-1, 450.2 to 2390.2 ng g^-1, and 233.8 to 9827.3 ng g^-1 for ∑_PAHs, ∑_n-alk, and ∑_sterols, respectively. Concentrations and patterns of PAH, AH, and sterol ratio distribution changed over time and may be associated with different episodes in the history of the city of Fortaleza. The marker ratio distribution in the sediment core revealed an overlap of natural and anthropogenic sources, with degraded oil, biogenic inputs, pyrogenic processes, and fecal contamination from humans and animals in the past changing to petroleum fossil inputs and high contamination from sewage in the present day. The distribution of markers and the chronological history of Fortaleza revealed two distinct periods related to human activities during the development of the city. In the first period (prior to the 1950s), the main human activities were animal breeding and the use of biomass for domestic activities, public and cargo transportation, and commercial activities, especially food production. In the second period (after the 1950s), expansion of the city occurred due to the so-called Brazilian economic miracle and the main human activities were industrialization and urbanization processes, involving deforestation, paving, sewage discharge, and petroleum combustion.

Dealing with complex contamination scenarios: using a multi-geochemical approach to assess environmental quality and identify pollution sources in a semi-arid estuary from Brazil

The Jundiaí-Potengi Estuary (EJP) is located on the semi-arid coast of northeastern Brazil and is influenced by multiple sources of contamination. The sediment quality of EJP was assessed by using a multi-geochemical approach during the dry and wet seasons. Sediments were analyzed for concentrations of nutrients, metals, polycyclic aromatic hydrocarbons (PAHs), pesticides, hormones (natural and synthetic), and sterols. The results were integrated by multivariate methods. The sediment was altered by the presence of contaminants from anthropogenic and natural sources. The middle and lower estuarine areas were considered more degraded in both seasons. In these regions, metals, hormones, sterols, and PAHs were found, indicating that these regions are severely affected by industrial, sanitary and aquaculture effluents, combustion of fossil fuels, and oil spills. The upstream region was contaminated by pesticides. The contamination pattern along the EJP shows the prevalence of local sources which continuously release the chemicals into the estuary. Worse conditions occurred during the rainy season, when the runoff from urban and rural areas is more intense and carries a greater load of contaminants to the EJP.

Levels, source appointment, and ecological risk of petroleum hydrocarbons in tropical coastal ecosystems (northeast Brazil): Baseline for future monitoring programmes of an oil spill area

We reviewed 20 years of levels, sources, and environmental risks related to the main petroleum hydrocarbons in the northeast region of Brazil. The aim of this study was to conduct a systematic review to serve as a comprehensive baseline for future monitoring programmes related to the oil spill disaster in 2019/2020. Most contamination levels of both PAHs and AHs were classified as low, except those in specific areas influenced by human activities, such as ports, highly urbanised mangroves, or rivers of medium-sized cities with inadequate liquid and solid waste treatment. Most hydrocarbons were linked to natural sources and burning processes, except in regions of extraction activities and petrochemical facilities as well as highly urbanised areas, where degraded petroleum and oil hydrocarbons predominated. Only 2.5% of the samples exceeded threshold effect levels for ∑_16-PAHs and no samples exceeded probable effect levels. When regional threshold levels were used, however, the probable effect for the ∑_16-PAHs measured was high, ranging from 5.8 to 6.1%. The few studies reporting biological responses showed that hydrocarbons from anthropogenic sources can induce adverse effects on marine organisms even at low to moderate levels. As the region has recently received a considerable quantity of crude oil, studies should be prioritised for a more precise assessment of the impact of this oil spill.

Sediment contamination and toxicity of Marine Protected Areas in southeastern Brazilian coast: A baseline for management planning

Recent studies have shown that the effectiveness of establishing Marine Protected Areas (MPAs) is threatened by toxic effects of contaminants. São Paulo is the most economically developed state of Brazil, and its coast is protected by a system of MPAs, including the North Shore Marine Protected Area (NSMPA). The present study provides a first assessment of sediment quality in NSMPA and two reference sites. Concentrations of arsenic (As), metals (Al, Fe, Cd, Cr, Cu, Ni, Pb, and Zn) and polycyclic aromatic hydrocarbons (PAHs) and its sources were determined. Comparisons with sediment quality guidelines indicated low contamination, as confirmed by the Geoaccumulation Index, which classified the results as background levels. Whole-sediment exposures of the amphipod Tiburonella viscana were performed to estimate possible acute effects, but samples exhibited no toxicity. The results presented in this study represent a baseline for further monitoring programs of MPAs, supporting conservation actions of management plans.