RESUMO
This research aimed at implementing and validating a method for analysis of pesticide residues in crops. QuEChERS extraction method with PSA purification was used following analyzes by gas chromatography with tandem mass spectrometry in Selected Reaction Monitoring mode. A short run method was successfully developed for the determination of 41 pesticides, confirmed by two precursor-products for each analyte. The calibration curve for each analyte was linear at concentration range from 1 to 500 µg kg-1 with correlation coefficients higher than 0.99, low limits of detection (0.03 - 10.22 µg kg-1) and satisfactory precision. The developed method was used to investigate apples; mangos; strawberries; cucumbers and tomatoes from the Rio de Janeiro Food Distribution Center (CEASA).Most of the targeted pesticides (78%) were below detection limits. Apple and strawberry presented the highest pesticide contamination levels, many of which are not authorized by tthe Brazilian national regulatory agency (ANVISA).
Assuntos
Produtos Agrícolas/química , Cromatografia Gasosa-Espectrometria de Massas/métodos , Resíduos de Praguicidas/análise , Piretrinas/análise , Extração em Fase Sólida/métodos , Espectrometria de Massas em Tandem/métodos , Triazinas/análise , Brasil , Cucumis sativus/química , Contaminação de Alimentos/análise , Fragaria/química , Solanum lycopersicum/química , Malus/química , Mangifera/químicaRESUMO
Investigation were carried out targeting distribution and source apportioning of hydrocarbons in surface sediments from shallow to deep waters in the Campos Basin, one of the most important oil-producing provinces in Brazil. The observed levels of aliphatic (≤ 124 µg g-1) and polycyclic aromatic hydrocarbons (PAHs ≤ 599 ng g-1) are lower than those considered relevant for environmental risk to the benthic habitats. Higher median concentrations of aliphatic hydrocarbons (8.49 µg g-1) and PAHs (84.8 ng g-1) in the middle slope sediments (700-1000-m water depths) showed the influence of hydrodynamics upon hydrocarbon accumulation in the sediments. Diagnostic ratios and conventional statistical analysis applied to hydrocarbon data produced insufficient information on the contribution of different sources. These traditional approaches do not consider the potential changes affecting source assignment and therefore cannot deal with the uncertainties. The fuzzy logic applied as an alternative method for data treatment successfully incorporated the uncertainties in the differentiation between petrogenic and pyrolytic sources, including those due to degradation. Moreover, by using fuzzy logic, it was possible to identify that water circulation patterns, mass transport, deposition, and degradation processes are more relevant factors in determining hydrocarbon composition than source proximity.
Assuntos
Alcanos/análise , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Campos de Petróleo e Gás , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Brasil , Lógica Fuzzy , Água do Mar/químicaRESUMO
The Potiguar Basin has oil and gas production fields offshore and onshore. All treated produced water (PW) from these fields is discharged through submarine outfalls. Although polycyclic aromatic hydrocarbons (PAHs) are minor constituents of PW, their input into the marine ecosystem is environmentally critical due to potential ecological hazards. A 2-year monitoring program was conducted in the vicinity of the outfalls to evaluate PAH bioaccumulation in marine life from PW discharges. The study was performed using transplanted bivalves Crassostrea brasiliana and semipermeable membrane devices (SPMDs) to measure PAH concentrations via bioaccumulation and in seawater. The bioaccumulation of PAH in transplanted bivalves reached up to 1105 ng g(-1) in the vicinity of the monitored outfall. Significantly lower PAH concentrations were found in the reference area in comparison to the studied area around the outfalls. Time-integrated PAH concentrations in seawater ranged from 38 to 0.3 ng L(-1) near the outfalls and from 10 ng L(-1) to not detected in the reference area. Both measurement techniques were found to be effective for determining a gradient of descending PAH concentrations from the outfalls. In addition, this study also evaluated the bioavailability of PAH for local marine biota and provided information about the influence of PW discharges on the water quality of marine ecosystems.
Assuntos
Hidrocarbonetos Policíclicos Aromáticos/análise , Água do Mar/química , Poluentes Químicos da Água/análise , Brasil , Monitoramento Ambiental/métodosRESUMO
Concentrations of PAHs and metals were obtained from mussels collected in beaches, coastal island and estuary of the Macaé coast, the main operational basin for offshore oil exploration in Brazil. This survey provides reference levels for scenarios of increasing exploration, as well as for other areas of the coast undergoing urbanization to support exploration. As expected, urban areas such as the Macaé river estuary presented high concentrations of PAHs, although unsuspected sites such the island also presented signs of contamination. PAH in mussels originated from pyrolytic and petrogenic sources. Metals were typical of non-contaminated coastal environments, although Cr concentrations were above Brazilian Reference Levels.
Assuntos
Monitoramento Ambiental/métodos , Metais Pesados/análise , Campos de Petróleo e Gás , Perna (Organismo)/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Rios/química , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Estuários , Sedimentos Geológicos/químicaRESUMO
Several anthropogenic factors, including contamination by oil spills, constitute a threat to coral reef health. Current methodologies to remediate polluted marine environments are based on the use of chemical dispersants; however, these can be toxic to the coral holobiont. In this study, a probiotic bacterial consortium was produced from the coral Mussismilia harttii and was trained to degrade water-soluble oil fractions (WSFs). Additionally, we assessed the effect of WSFs on the health of M. harttii in tanks and evaluated the bacterial consortium as a bioremediation agent. The consortium was responsible for the highly efficient degradation of petroleum hydrocarbons, and it minimised the effects of WSFs on coral health, as indicated by raised photosynthetic efficiencies. Moreover, the impact of WSFs on the coral microbiome was diminished by the introduced bacterial consortium. Following introduction, the bacterial consortium thus had a dual function, i.e promoting oil WSF degradation and improving coral health with its probiotic features.
Assuntos
Biodegradação Ambiental , Biotransformação , Recifes de Corais , Microbiota , Poluição por Petróleo , Probióticos , Bactérias/classificação , Bactérias/genética , Bactérias/metabolismo , Hidrocarbonetos/metabolismo , Processos Fotoquímicos , Poluentes Químicos da ÁguaRESUMO
The present study evaluates the potential of Hymeniacidon heliophila as bioindicator of PAH contamination. For this, concentration of 33 PAH was determined in organisms from sites with different contamination level including the heavily polluted Guanabara Bay, Rio de Janeiro, and less impacted coastal areas. PAH concentration and typology were determined in sponges collected from different depths and in two different seasons. The brown mussel broadly studied as bioindicator was also sampled from the same sites for comparison. Both species provided similar information on total PAH concentration which is related to site contamination level. Sponges, however, revealed slight tendency to accumulation of combustion-derived PAH in relation to petrogenic compounds. Differences in PAH typology between species may derive from the interspecific variation in particle size ingestion. Different hydrocarbon typologies were observed in sponges from dry and wet season and PAH concentration varied with depth. H. heliophila may be used as an alternative approach to investigate the presence and sources of PAH in estuarine areas.
Assuntos
Monitoramento Ambiental/métodos , Hidrocarbonetos Policíclicos Aromáticos/análise , Poríferos , Poluentes Químicos da Água/análise , Animais , Brasil , Tamanho da Partícula , Perna (Organismo) , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Poríferos/metabolismo , Poluentes Químicos da Água/farmacocinéticaRESUMO
Pyrene metabolites in urine and micronucleus in haemocytes of crabs (Ucides cordatus) were tested as biomarkers of exposure to oil derived PAHs in mangrove sediments. The goal was to verify how well pyrene metabolites in urine represent levels of oil contamination in mangroves and whether the micronuclei assay indicates exposure. For this, bioassays were performed using crabs from clean and contaminated areas, and field studies were conducted in four mangroves. Results of the bioassay show that U. cordatus assimilates, metabolises, and excretes pyrene in urine as pyrene-1-glucoside, pyrene-sulphate and pyrene-conjugate. OH-pyrene-sulphate was the major metabolite produced/excreted over 120 h of observation by crabs from the clean mangrove. The production/excretion of pyrene-1-glucoside in this case increased linearly with time at a rate of 2.3 x 10(-10)mol L(-1)day(-1). The number of micronuclei in haemocytes also increased with the time after pyrene inoculation, indicating that exposure to pyrene triggers genotoxic and mutagenic response. In crabs from a heavily oil-contaminated mangrove pyrene-1-glucoside was the major metabolite, an indication that production/excretion of a certain metabolite varies depending on adaptation of the animal to the environment. A highly significant correlation was found between the concentration of pyrene metabolites in urine of field crabs expressed as OH-pyrene equivalents and the sum of 38 PAHs determined in hepatopancreas/sediments (r=0.825, n=23, p<0.05). The response of these crabs to the micronuclei assay was not significantly related to concentration of individual or total PAHs. Nevertheless, metabolite results prove U. cordatus as excellent bioindicator for evaluating environmental quality in mangrove areas as related to PAHs and oil contamination.
Assuntos
Braquiúros/metabolismo , Sedimentos Geológicos/química , Glucuronatos/urina , Hidrocarbonetos Policíclicos Aromáticos/farmacocinética , Poluentes Químicos da Água/farmacocinética , Animais , Avicennia , Biomarcadores/urina , Brasil , Ecotoxicologia , Masculino , Testes para Micronúcleos , Microscopia de Fluorescência , Hidrocarbonetos Policíclicos Aromáticos/urina , Pirenos , Estatísticas não Paramétricas , Poluentes Químicos da Água/urinaRESUMO
This study is aimed at verifying the relevance of Ucides cordatus as a bioindicator of oil contamination and PAH bioavailability in mangrove sediments. For this, crabs and sediment cores were sampled from five mangroves, including an area suspected of contamination derived from an MF380 oil spillage, and analyzed for the 16 PAH in the USEPA priority list as well as for the five series of alkylated homologues. Concentrations in sediments varied from 35 microg kg-1 in the lower core layer of the control area to 33,000 microg kg-1 in the upper layer of the most contaminated area. Total PAH contents in crabs varied from 206 to 62,000 microg kg-1 and were closely correlated to that in sediments. In general, individual PAH profiles in both matrices were in good agreement. Phenanthrenes, however, were more predominant in crabs making up to 30-46% of the Total PAH. Accumulation factors found in the range of 0.7 to 35 were highly variable even after normalizing concentrations for organic carbon and lipid content. Survival in highly contaminated environment and reliable record of environmental contamination in the tissue provide evidence that U. cordatus is an excellent bioindicator for oil in mangroves.