Estudo ecotoxicológico e avaliação do risco ambiental da cocaína em ecossistemas marinhos
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Data
2022-01-31
Autores
Fontes, Mayana Karoline
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Universidade Estadual Paulista (Unesp)
Resumo
Os esgotos urbanos representam uma importante fonte de poluição em ecossistemas marinhos, devido, principalmente, ao aumento populacional em regiões metropolitanas costeiras e à ineficiência dos processos de coleta, tratamento e disposição de efluentes domésticos. Entre as principais substâncias que podem ser encontradas nos efluentes estão os produtos farmacêuticos, de cuidados pessoais e drogas ilícitas, tais como a cocaína, que é considerada como um sério problema de saúde pública. Os emissários submarinos representam o principal mecanismo de liberação de contaminantes de preocupação emergente (como as drogas ilícitas) no ambiente marinho. Estudos anteriores identificaram a presença de cocaína (COC) em água superficial continental e costeira, bem como efeitos biológicos em concentrações ambientalmente relevantes. Dessa forma, o presente trabalho tem como objetivo a realização de uma avaliação do risco ambiental de cocaína em ambientes costeiros através de uma metodologia escalonada que contemple a quantificação em matrizes ambientais na Baía de Santos (água superficial, sedimento e mexilhões) e ensaios ecotoxicológicos empregando como modelos o mexilhão Perna perna e o peixe Anguilla anguilla. Os mexilhões foram expostos a duas diferentes concentrações de cocaína (200 ng.l-1 e 2000 ng.l-1), a um controle de água do mar e um controle de solvente, por 168h. Ao todo, foram 21 mexilhões divididos em 2 aquários por tratamento. Após os períodos de exposição (48h, 96h e 168h), 7 mexilhões eram aleatoriamente retirados dos aquários e submetidos à avaliação de citotoxicidade (pelo ensaio do Tempo de Retenção do Vermelho Neutro) e posteriormente eram excisados para retirada de tecidos (músculo adutor, glândula digestiva, brânquia e gônadas) para análise de biomarcadores (dopamina- DOPA; 5-hydroxytryptamine- 5-HT – serotonina; acetilcholinesterase- AChE; monoamina oxidase- MAO; ciclooxigenase- COX; transporte mitocrondrial de elétrons- MET; lipidios totais- TLP; 7-ethoxiresorufin O-deetilase – EROD; dibenzilfluoresceina dealkilase – DBF; glutationa S-transferase – GST; glutationa peroxidase – GPX; DNA danos em DNA; e peroxidação lipídica – LPO). A capacidade da cocaína bioacumular nos mexilhões também foi verificada. Além disso, peixes (Anguilla anguilla) também foram expostos à cocaína (20 ng.l−1) para investigar potenciais danos histopatológicos, imunohistoquímicos (3β-hidroxisteroide dehidrogenase- 3β-HSD; 17β- hidroxisteroid dehidrogenase- 17β-HSD type 3; e P450 aromatase) e endócrinos (hormonônio folículo estimulante- FHS; hormônio luteinizante- LH and cortisol) da cocaína em vertebrados. Os resultados demonstram que a cocaína foi encontrada na Baía de Santos em concentrações variando de 1.91 – 203.6 ng.l−1, sendo as maiores concentrações detectadas na primavera/verão, período que coincide com o aumento populacional na Baixada Santista devido ao início da alta temporada. No sedimento, as concentrações quantificadas variaram de 0.94 – 46.85 ng.g−1. A cocaína também foi detectada no tecido de mexilhões coletados na Baía em concentrações variando de 0.914-4.58 μg·kg−1 (peso úmido). O fator de bioacumulação calculado variou de 163 – 1454 l·kg−1. Quanto às vias metabólicas investigadas, foram observadas alterações nas atividades de EROD e DBF, além de GST e GPx, indicando comprometimento na metabolização e resposta antioxidante. A exposição à cocaína provocou citotoxicidade nos mexilhões, que foi observada pela reduzida estabilidade da membrana lisossomica dos hemócitos, além do aumento significativo de peroxidação lipídica e danos em DNA. A cocaína aumentou os níveis de neurotransmissores (dopamine e serotonina) nos mexilhões em todas as concentrações testadas. Já após 168h foi observada uma redução nos níveis de AChE e COX. Além disso, foi observada um aumento nos níveis de MET e TLP em ambas as concentrações. Os peixes expostos à cocaína apresentaram um atraso no desenvolvimento e maturação dos folículos ovarianos, fato que pode comprometer a reprodução desses organismos. Isso também foi demonstrado pela menor expressão de 3β-HSD, e P450 aromatase, bem como menores níveis de FHS e LH. Os resultados indicam que concentrações ambientalmente relevantes de cocaína, mesmo na ordem de ng.l-1 são capazes de afetar negativamente a saúde dos animais marinhos a partir de perturbações no sistema reprodutivo e citogenotoxicidade. A avaliação de risco realizada apontou para quocientes situados entre os níveis moderado e alto para Baía de Santos. É preciso melhorar a estrutura de coleta e tratamento de esgoto em regiões costeiras a fim de minimizar o descarte de efluentes contaminados com drogas ilícitas em ambientes marinhos. Além disso, é importante que essas substâncias sejam incluídas em programas de monitoramento da qualidade de água, a fim de se estabelecerem parâmetros de segurança que permitam a preservação dos recursos naturais e da saúde humana.
Urban sewage represents an important source of pollution to marine ecosystems, mainly due to the population growth on coastal metropolitan regions and the inefficiency of the processes of collection, treatment and disposal of domestic effluents. Pharmaceutical, persoanl care products and illicit drugs, such as cocaine, constitute some of the main substances found in domestic effluents representing serious problem to the public health. Submarine sewage outfalls represent the main source of contaminants of emerging concern (such as illicit drugs) into the marine environment. Previous studies have identified the presence of cocaine (COC) in inland and coastal surface water, as well as biological effects at environmentally relevant concentrations. The present work aimed to assess of the environmental risk of cocaine in coastal environments through a tiered approach that included the COC (and by products) quantification in environmental matrices of Santos Bay (surface water, sediment and mussels) and ecotoxicological tests using as models the mussel Perna perna and the fish Anguilla anguilla. Mussels were exposed to two different concentrations of cocaine (200 ng.l-1 and 2000 ng.l-1), a seawater control and a solvent control, for 168h. The mussels (21 specimens) were divided into 2 aquariums per treatment. After the exposure periods (48h, 96h and 168h), 7 mussels were randomly removed from the aquariums and submitted to cytotoxicity evaluation (by the Neutral Red Retention Time assay) and later they were excised for tissue removal (adductor muscle, digestive tract, gills and gonads) for the analysis of biomarkers (dopamine-DOPA; 5- hydroxytryptamine- 5-HT - serotonin; acetylcholinesterase-AChE; monoamine oxidase-MAO; cyclooxygenase-COX; mitochondrial electron transport-MET; total lipids- TLP; 7- ethoxyresorufin O-deethylase – EROD; dibenzylfluorescein dealkylase – DBF; glutathione S- transferase – GST; glutathione peroxidase – GPX; DNA damage to DNA; and lipid peroxidation – LPO). The bioaccumulation of COC in mussels soft tissues was also verified. In addition, fish (Anguilla anguilla) were also exposed to cocaine (20 ng.l−1) to investigate potential histopathological, immunohistochemical (3β-hydroxysteroid dehydrogenase-3β-HSD; 17β-hydroxysteroid dehydrogenase-17β-HSD type 3; and P450 aromatase) and endocrine (follicle stimulating hormone-FHS); luteinizing hormone- LH and cortisol) damages caused by cocaine in marine vertebrates. Cocaine was found in Santos Bay at concentrations ranging from 1.9 – 203.6 ng.l-1, with the highest concentrations detected in spring/summer, a period that coincides with the population increase in Baixada Santista due to the beginning of the warmer high season. In the sediment, the quantified concentrations ranged from 0.94 – 46.85 ng.g−1. Cocaine was also detected in the soft tissue of mussels collected in the Bay at concentrations ranging from 0.914-4.58 μg·kg−1 (wet weight). The calculated bioaccumulation factor ranged from 163 – 1454 l·kg−1. As for the metabolic pathways investigated, changes were observed in the activities of EROD and DBF, in addition to GST and GPx, indicating impairment in metabolism and antioxidant response. Cocaine exposure caused cytotoxicity in mussels, which was observed by the reduced stability of the lysosomal membrane of hemocytes, and the significant increase in lipid peroxidation and DNA damage. Cocaine increased the levels of neurotransmitters (dopamine and serotonin) in mussels at all concentrations tested. After 168h, a reduction in AChE and COX levels was observed. In addition, an increase in MET and TLP levels was observed at both concentrations. Fish exposed to cocaine showed a delay in the development and maturation of ovarian follicles, a fact that can compromise the reproduction of these organisms. This was also demonstrated by lower expression of 3β-HSD, and P450 aromatase, as well as lower levels of FHS and LH. The results indicated that environmentally relevant concentrations of cocaine, even in the order of ng.l-1, are capable of negatively affecting the health of marine animals through disturbances in their reproductive system and cytogenotoxicity. The risk assessment carried out pointed to moderate to high risks in Santos Bay. It is necessary to improve the structure of sewage collection and treatment in coastal regions in order to minimize the disposal of effluents contaminated with illicit drugs in marine environments. Furthermore, it is important that these substances are included in water quality monitoring programs, in order to establish safety parameters that allow the preservation of natural resources and human health.
Urban sewage represents an important source of pollution to marine ecosystems, mainly due to the population growth on coastal metropolitan regions and the inefficiency of the processes of collection, treatment and disposal of domestic effluents. Pharmaceutical, persoanl care products and illicit drugs, such as cocaine, constitute some of the main substances found in domestic effluents representing serious problem to the public health. Submarine sewage outfalls represent the main source of contaminants of emerging concern (such as illicit drugs) into the marine environment. Previous studies have identified the presence of cocaine (COC) in inland and coastal surface water, as well as biological effects at environmentally relevant concentrations. The present work aimed to assess of the environmental risk of cocaine in coastal environments through a tiered approach that included the COC (and by products) quantification in environmental matrices of Santos Bay (surface water, sediment and mussels) and ecotoxicological tests using as models the mussel Perna perna and the fish Anguilla anguilla. Mussels were exposed to two different concentrations of cocaine (200 ng.l-1 and 2000 ng.l-1), a seawater control and a solvent control, for 168h. The mussels (21 specimens) were divided into 2 aquariums per treatment. After the exposure periods (48h, 96h and 168h), 7 mussels were randomly removed from the aquariums and submitted to cytotoxicity evaluation (by the Neutral Red Retention Time assay) and later they were excised for tissue removal (adductor muscle, digestive tract, gills and gonads) for the analysis of biomarkers (dopamine-DOPA; 5- hydroxytryptamine- 5-HT - serotonin; acetylcholinesterase-AChE; monoamine oxidase-MAO; cyclooxygenase-COX; mitochondrial electron transport-MET; total lipids- TLP; 7- ethoxyresorufin O-deethylase – EROD; dibenzylfluorescein dealkylase – DBF; glutathione S- transferase – GST; glutathione peroxidase – GPX; DNA damage to DNA; and lipid peroxidation – LPO). The bioaccumulation of COC in mussels soft tissues was also verified. In addition, fish (Anguilla anguilla) were also exposed to cocaine (20 ng.l−1) to investigate potential histopathological, immunohistochemical (3β-hydroxysteroid dehydrogenase-3β-HSD; 17β-hydroxysteroid dehydrogenase-17β-HSD type 3; and P450 aromatase) and endocrine (follicle stimulating hormone-FHS); luteinizing hormone- LH and cortisol) damages caused by cocaine in marine vertebrates. Cocaine was found in Santos Bay at concentrations ranging from 1.9 – 203.6 ng.l-1, with the highest concentrations detected in spring/summer, a period that coincides with the population increase in Baixada Santista due to the beginning of the warmer high season. In the sediment, the quantified concentrations ranged from 0.94 – 46.85 ng.g−1. Cocaine was also detected in the soft tissue of mussels collected in the Bay at concentrations ranging from 0.914-4.58 μg·kg−1 (wet weight). The calculated bioaccumulation factor ranged from 163 – 1454 l·kg−1. As for the metabolic pathways investigated, changes were observed in the activities of EROD and DBF, in addition to GST and GPx, indicating impairment in metabolism and antioxidant response. Cocaine exposure caused cytotoxicity in mussels, which was observed by the reduced stability of the lysosomal membrane of hemocytes, and the significant increase in lipid peroxidation and DNA damage. Cocaine increased the levels of neurotransmitters (dopamine and serotonin) in mussels at all concentrations tested. After 168h, a reduction in AChE and COX levels was observed. In addition, an increase in MET and TLP levels was observed at both concentrations. Fish exposed to cocaine showed a delay in the development and maturation of ovarian follicles, a fact that can compromise the reproduction of these organisms. This was also demonstrated by lower expression of 3β-HSD, and P450 aromatase, as well as lower levels of FHS and LH. The results indicated that environmentally relevant concentrations of cocaine, even in the order of ng.l-1, are capable of negatively affecting the health of marine animals through disturbances in their reproductive system and cytogenotoxicity. The risk assessment carried out pointed to moderate to high risks in Santos Bay. It is necessary to improve the structure of sewage collection and treatment in coastal regions in order to minimize the disposal of effluents contaminated with illicit drugs in marine environments. Furthermore, it is important that these substances are included in water quality monitoring programs, in order to establish safety parameters that allow the preservation of natural resources and human health.
Descrição
Palavras-chave
Cocaína, Ecossistemas marinhos, Poluição marinha, Marcadores bioquímicos, Mexilhões Perna perna, Enguia européia, Cocaine, Marine ecosystems, Perna perna mussel, European eels, Biomarkers