RESUMO
The mussel Perna perna was used to monitor and assess areas suspected of oil contamination by transplanting animals from unimpacted to impacted sites and vice versa. The deployment lasted for three months during which total PAH were measured in seawater samples collected every 15 days. PAH concentrations were determined in mussel tissue monthly. The lysosomal neutral red assay and the condition index were used as biomarkers of the adverse biological effects. The PAH concentration in mussels at unimpacted sites, prior to deployment was ca. 100 microg kg(-1) but increased to 300 microg kg(-1) after three months at the contaminated site. Mussels transplanted to the uncontaminated site showed a decrease from 380 to 80 microg kg(-1). Significant changes in lysosomal stability occurred within one month of the beginning of the transposition; in contrast condition indexes were not correlated with the observed changes in PAH concentration.
Assuntos
Monitoramento Ambiental/métodos , Perna (Organismo)/efeitos dos fármacos , Hidrocarbonetos Policíclicos Aromáticos/análise , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade , Animais , Água do Mar/químicaRESUMO
The investigation aimed primarily at understanding the PAH record in inter-tidal mussel tissues and evaluating the bivalve performance as a bioindicator for oil contamination. The species Perna perna was used as test organism since it is abundantly distributed in coastal areas of the Americas, Africa and elsewhere. The study was carried out in Guanabara Bay and comprised two observation phases: phase one included seasonal sampling in 8 sites, whereas in phase two 4 sites were examined over 4 years. Among the 35 determined PAH (60-90 microg kg(-1) up to 4000-6000 microg kg(-1)) alkylated homologues predominated by more than 80%. The PAH profile in inter-tidal mussels is largely petrogenic with high contribution of dibenzothiophenes (DBT) and phenanthrenes (Ph). The prevailing petrogenic fingerprint, confirmed by diagnostic ratios, is linked to the properties of the inter-tidal habitat, which favors exposure to oil films. C2DBT/C2Ph and C3DBT/C3Ph ratios, however, show a wide range of values uncorrelated to specific oils. Micronucleus frequencies are significantly related to PAH concentrations, especially to those of alkylated homologues. Genotoxic expression appears at concentrations as low as 300 microg kg(-1) summation operator 35 PAH.
Assuntos
Monitoramento Ambiental/métodos , Perna (Organismo)/química , Hidrocarbonetos Policíclicos Aromáticos/análise , Poluentes Químicos da Água/análise , Animais , Brasil , Análise Fatorial , Testes para Micronúcleos , Testes de Mutagenicidade , Hidrocarbonetos Policíclicos Aromáticos/toxicidade , Fatores de Tempo , Poluentes Químicos da Água/toxicidadeRESUMO
Coastal marine environments, especially semienclosed systems such as bays, are under unrelenting stress caused by urban and industrial development. Biomonitoring plays a vital role in strategies to identify, assess, and control stressors. However, due to the magnitude of the challenge there is a demand for new and innovative approaches to provide timely and accessible information to environmental managers and policy makers. The present work aimed to assess hydrocarbon levels in sediments from petroleum-related industrial areas at Todos os Santos Bay (Brazil) and associate them to toxicity-induced responses (neutral red retention (NRR) assay) by the burrowing clam Anomalocardia brasiliana. Surface sediments collected during the dry and rainy seasons were analyzed for aliphatic and aromatic hydrocarbons. At the control site, hydrocarbon levels were low and mainly biogenic. The aliphatic hydrocarbon ("total unresolved complex mixture," alkanes, and isoprenoids) concentrations indicated a chronic situation with very little "fresh" oil contamination at the oil-related sites. The polycyclic aromatic hydrocarbons indicated sites moderately contaminated by chronic oil and some pyrolytic input. The effects of those contaminants were assessed by the lysosomal NRR assay applied to A. brasiliana hemocytes. Sediment toxicity at the oil-related sites was evidenced by the lowered capacity of the lysosomes to retain the neutral red dye compared to results from the control site. This research indicates that the NRR assay is a useful and efficient screening technique able to discriminate polluted from clean sites.
Assuntos
Bivalves/fisiologia , Hidrocarbonetos/análise , Petróleo , Poluentes Químicos da Água/análise , Animais , Bioensaio , Brasil , Meio Ambiente , Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Indicadores e Reagentes/análise , Lisossomos/química , Vermelho Neutro/análise , Estações do AnoRESUMO
Urine and haemolymph can be repeatedly sampled from crabs with no (or limited) damage to the organism. Their analysis offers a measure of the animals' exposure to biologically available contaminants. Shore crabs (Carcinus maenas) were exposed to the PAHs phenanthrene and pyrene at concentrations ranging from 20 to 200 microg l(-1). After 48 h, urine and haemolymph samples were taken and analysed using ELISA and UV-fluorescence spectrophotometry. High correlations were recorded between the two sets of results from the urine analyses (r2 = 0.83 for phenanthrene and r2 = 0.88 for pyrene). Contaminant concentrations were much lower in haemolymph than in the urine. Analyses of urine taken from crabs collected from clean and contaminated sites confirm the suitability of these analyses for environmentally exposed organisms. Again, a good correlation was recorded between the ELISA and spectrofluorimetric analysis (r2 = 0.83). In this instance, difficulties were experienced with haemolymph analyses owing to a lack of sensitivity.