Interactive effects of microplastics and benzo[a]pyrene on two species of marine invertebrates.

This study aimed to evaluate B[a]P and low-density polyethylene microplastics (MPs) toxicty, alone and in mixture (0.03 to 30 µg L-1 of B[a]P; and 5, 50 and 500 mg L-1 for MPs). Five mg L-1 of MPs is considerably higher than commonly reported environmental concentrations, although it has been reported for marine environments. Individual (sea urchin embryo-larval development and mortality of mysids) and sub-individual responses (LPO and DNA damage in mysids) were assessed. The toxicity increased as the B[a]P concentration increased, and microplastics alone did not cause toxicity. B[a]P toxicity was not modified by the lowest concentration of MPs (5 mg L-1), but at higher MPs concentrations (50 and 500 mg L-1), the effects of B[a]P on sea urchin development and in biomarkers in mysids were diminished. Microplastics interacted with B[a]P in seawater, reducing its toxicity, probably due to adsorption of B[a]P to the surface of microplastics.

Plastic pellets make Excirolana armata more aggressive: Intraspecific interactions and mortality in field and laboratory ecotoxicological assays.

Microplastics, including plastic pellets, get stranded on sandy beaches. They persist in the oceans for long periods and frequently carry contaminants. Acute and chronic toxicity has been observed when marine organisms are exposed to high densities of plastic pellets in laboratory assays. We investigated the toxicity of beach-stranded plastic pellets on macrobenthic populations (Excirolana armata; Crustacea; Isopoda) under natural conditions (in situ). We simulated different pellets densities on a beach not contaminated by pellets, exposing isopods for 6 h and testing possible behavioral responses (i.e., vertical displacement) and mortality effects. No effect was observed on vertical displacement, but higher mortality was reported for organisms exposed to plastic pellets. The lowest pellet density tested commonly found in coastal areas was sufficient to trigger mortality. We also observed that lethargic individuals (near-death) were preyed on by the healthy individuals remaining in the test chambers.

Bioavailability of polycyclic aromatic hydrocarbons to penguins on the coast of southeastern Brazil.

Bioavailability of polycyclic aromatic hydrocarbons on São Paulo state coast (southeastern Brazil) was evaluated through the analysis of biliary metabolites in Spheniscus magellanicus (n = 79). The animals analyzed in present study were either found dead during beach monitoring procedures or died at rehabilitation centers. Analyses of naphthalene (NAP), phenanthrene (PHE) and benzo[a]pyrene (BaP) metabolites were performed using a high-performance liquid chromatograph equipped with fluorescence detectors. Total metabolite (TM) concentrations ranged from below the method quantification limit to 270 µg g-1 of bile. TM concentrations were mainly composed of NAP metabolites, followed by PHE metabolites. BaP metabolites were detected in only two samples. This is the first study using PAHs metabolites in S. magellanicus to assess the bioavailability of these compounds in coastal regions.

Historical inputs of polycyclic aromatic hydrocarbons in the preserved tropical estuary of the Itapicuru River, Bahia, Brazil.

The aim of present study was to evaluate temporal changes in the distribution of polycyclic aromatic hydrocarbons (PAHs) in the estuary of the Itapicuru (Brazil). A sediment core was sampled in the study area. Concentrations of the 16 priority PAHs were analyzed using gas chromatography coupled to a mass spectrometry. A gas flow proportional counter was used to estimate the sedimentation rate through the determination of 210Pb. Granulometric fractions and total organic carbon (TOC) concentrations were also evaluated. Concentrations of TOC and PAHs ranged from 0.65 to 2.51% and 1.98 to 43.1 ng g-1 (dry weight), respectively. Significant correlations (p < .05) were found between the mud content in the sediment core samples and concentrations of both TOC and PAHs. Higher PAH concentrations occurred after the 1950s. The main sources of PAHs over time were local human activities on the northern coast of the state of Bahia.

Combining geochemical and chemometric tools to assess the environmental impact of potentially toxic elements in surface sediment samples from an urban river.

This article investigates sediments collected from the banks of the Subaé River located in Todos os Santos Bay in the state of Bahia, Brazil, in 2018, twenty-five years after the closing of a former lead alloy processing plant. Ten sediment samples were collected at different points of the course of the river and its estuarine region. Chemometric tools were used to determine geochemical correlations between the organic matter content and concentration of sulfides and potentially toxic metals. The inorganic geochemical variables (enrichment factor [EF]) used in this evaluation were concentrations of the Pb, Cd, Cu, Zn, and Ni. Chemical element analyses were performed using ICP-OES. To assess the interaction between metals and sulfide or metals and organic matter, concentrations of Pb, Cd, Cu, Zn, Ni, sulfide, and the silt-clay fraction constituted the organic geochemical parameters selected to characterize the amount of organic matter present in Subaé River sediment samples, determining the carbon content (%TOC) to compose the matrix of the principal component analysis (PCA) and hierarchical cluster analysis. PCA showed that 88.3% of the samples were representative for assessing correlations between geochemical variables. A tendency toward binding was found among Cu, Cd, Ni, and sulfide, as well as the silt-clay fraction. The concentrations (mg kg-1) of lead, zinc, and copper were higher in both collection campaigns, ranging from 4.72 to 31.34, 12.76 to 54.24, and 5.34 to 31.37, respectively. Pb and Zn were presented in elemental form when assessed as a function of the pH and Eh of the environment. Except for Cd (EF: 0.51 to 5.49), the other elements exhibited little or no potential pollution in the aquatic environment of the Subaé River.

Concentration and distribution of polycyclic aromatic hydrocarbons in oysters from Todos os Santos Bay (Bahia, Brazil).

The aim of the present study was to evaluate the presence of polycyclic aromatic hydrocarbons (PAHs) in oysters (Crassostrea rhizophorae) collected from Todos os Santos Bay (Bahia, Brazil). The total PAH concentration was highest in Madre de Deus (36.3 to 37.8 ng g-1 in dry weight, dw), which is located near a petrochemical complex, oil refinery, and commercial port. In the Paraguaçu river estuary, PAH concentrations varied between 23.2 and 25.7 ng g-1 dw. The lowest concentrations (1.55 ng g-1 dw) were found in the Jaguaribe river estuary, which can be considered a relatively preserved area. The main source of PAHs in the study areas was observed to be pyrogenic. Values of benzo[a]pyrene toxic equivalent ranged from 0.28 to 4.20. The concentrations of PAHs in oysters from the Paraguaçu river estuary and in Madre de Deus indicate the possible lifetime risk of developing cancer in humans who feed on it.

Distribution and sources of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of a Tropical Bay influenced by anthropogenic activities (Todos os Santos Bay, BA, Brazil).

The present study aimed to evaluate the distribution and origin of 16 Priority PAHs in surficial sediment samples of Todos os Santos Bay (TSB, Brazil). Total PAHs concentrations ranged from below the method detection limit (

Evaluation of polycyclic aromatic hydrocarbons bioavailability on Santos Bay (Brazil) through levels of biliary metabolites.

This study evaluated the PAH bioavailability from Santos Bay (Brazil) in 4 species of fish, using PAH biliary metabolites. The collection was done monthly, between July and December, in three different regions of Santos Bay. The metabolites were analyzed through a high performance liquid chromatograph with fluorescence detectors. Total metabolites concentrations ranged from 65.5 to 589µgg-1 of bile, evidencing PAH bioavailability on Santos Bay. Levels of phenanthrene and benzo[a]pyrene metabolites were in the classification range of areas moderate contaminated. Those concentrations were lower in Nebris microps and higher in Sphoeroides testudineus (p<0.05). Naphthalene metabolites concentrations did not differ significantly among fish species and were in the classification range of low contaminated areas. There were no significant spatial and temporal differences in levels among sampled areas. These results are environmentally important given the high levels of urbanization and the absence of biomonitoring data in this area.

Mugil curema as a PAH bioavailability monitor for Atlantic west sub-tropical estuaries.

This work aimed to evaluate the use of Mugil curema as a biomonitor for polycyclic aromatic hydrocarbon (PAH) bioavailability. Fish biliary metabolites from low-contaminated (Cananéia) and contaminated (Santos) Brazilian estuaries were analysed using a high-performance liquid chromatography apparatus coupled to fluorescence detectors connected in a series. In the Cananéia and Santos estuaries, total metabolite levels ranged from 0.85 to 34.4µgg-1 of bile and from 4.06 to 528µgg-1 of bile, respectively. Metabolite levels were not influenced by feeding status or sexual hormones (p<0.05), thus suggesting that M. curema is a good biomonitor for PAH bioavailability. In estuarine regions, it is possible to sample both the male and female genders of this species in any reproductive period.

Determination of Geochemically Important Sterols and Triterpenols in Sediments Using Ultrahigh-Performance Liquid Chromatography Tandem Mass Spectrometry (UHPLC-MS/MS).

A fast, sensitive, and selective ultrahigh-performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method that is able to quantify geochemical biomarkers in sediment is described. A pool of 10 sterols, which can be used as biomarkers of autochthonous (cholesterol, cholestanol, brassicasterol, ergosterol), allochthonous (stigmasterol, ß-sitosterol, campesterol, and stigmastanol) and anthropogenic (coprostanol and epicoprostanol) organic matter (OM), and three triterpenols (lupeol, α-amyrin, and ß-amyrin) were chosen as the analytes. The method showed excellent analytical parameters, and, compared with the traditional GC-MS methods that are commonly applied for the analysis of sterols, this method requires no sample cleanup or derivatization and presents improved values for the LOD and LOQ. UHPLC can separate the diastereoisomers (epicoprostanol, coprostanol, and cholestanol) and the isomers (lupeol, α-amyrin, and ß-amyrin). The method was successfully applied for the quantification of the biomarkers, and thus, it was applied to assess the OM sources and the impacts of anthropogenic activities in sediments from different environments, such as Antarctica and other Brazilian systems (Continental Shelf, São Sebastião Channel, and Santos Estuary). Unique profiles of the biomarkers were observed for the contrasting environments, and ß-amyrin and cholesterol were more predominant in the Santos Estuary and Antarctica samples, respectively. The sterol ratios indicated a higher level of sewage contamination in the Santos Estuary.

Mutagenicity of blue rayon extracts of fish bile as a biomarker in a field study.

Blue rayon (BR) in combination with the Salmonella/microsome assay was used to evaluate the mutagenicity of fish bile samples. Specimens of Mugil curema from two sites were collected over a 1-year period. Piaçaguera channel contains high concentrations of total polycyclic aromatic hydrocarbons (PAHs) and other contaminants, while Bertioga channel was considered the reference sites in this study. Bile was extracted with BR and tested with TA98, TA100, and YG1041 strains with and without S9 in dose response experiments. PAH metabolite equivalents were analyzed using reverse-phase high performance liquid chromatography /fluorescence. Higher mutagenic responses were observed for the contaminated site; YG1041 with S9 was the most sensitive strain/condition. Mutagenicity ranged from 3,900 to 14,000 rev./mg at the contaminated site and from 1,200 to 2,500 rev./mg of BR at the reference site. The responses of YG1041 were much higher in comparison with the TA98 indicating the presence of polycyclic compounds from the aromatic amine class that cause frameshift mutation. TA100 showed a positive mutagenic response that was enhanced following S9 treatment at both sites suggesting the presence of polycyclic compounds that require metabolic activation. benzo(a)pyrene, naphthalene, and phenanthrene metabolite equivalents were also higher in the bile of fish collected at the contaminated site. It was not possible to correlate the PAH metabolite quantities with the mutagenic potency. Thus, a combination of the Salmonella/microsome assay with YG1041 with S9 from BR bile extract seems to be an acceptable biomarker for monitoring the exposure of fish to mutagenic polycyclic compounds.