| Texto completo | |
| Autor(es): |
Moreira, Raquel Aparecida
;
Rocha, Giseli Swerts
;
Menezes da Silva, Lais Conceicao
;
Goulart, Bianca Veloso
;
Montagner, Cassiana Carolina
;
Gama Melao, Maria da Graca
;
Gaeta Espindola, Evaldo Luiz
Número total de Autores: 7
|
| Tipo de documento: | Artigo Científico |
| Fonte: | ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY; v. 206, p. 11-pg., 2020-12-15. |
| Resumo | |
The occurrence of pesticides and their mixtures in the environment can alter the ecological relationships between aquatic food chains. Since fipronil and 2,4-dichlorophenoxyacetic acid (2,4-D) are commonly found together in Brazilian water bodies, the present study aimed to investigate through an integrative approach the toxicity mechanisms of environmentally relevant concentrations of pesticides Regent (R) 800 WG (active ingredient - a.i. fipronil), DMA (R) 806 BR (a.i. 2,4-D) isolated and in mixtures on the green alga Raphidocelis subcapitata using multiple parameters: physiological (growth rate and chlorophyll a fluorescence), morphological (cell complexity and size), biochemical (composition of lipid classes) and related to the photosynthetic activity (variable fluorescence, the maximum quantum yield of the photosystem II - PSII - and the efficiency of the oxygen evolving complex - OEC - of PSII). The results indicated that fipronil significantly inhibited algal population growth, increased the chlorophyll a content (observed by fluorescence), cell size and lipid class content of triacylglycerol (TAG), free fatty acid (FFA) and acetone mobile polar lipid (AMPL) and, on the other hand, decreased variable fluorescence of algae. The tested concentrations of 2,4-D increased the chlorophyll a fluorescence, the cell size and the lipid classes TAG and FFA. The pesticide mixtures have had more effects on algae than isolated compounds, causing alterations in all parameters analyzed, including photosynthetic activity (maximum quantum yield and efficiency of the oxygen evolving complex of the PSII), in which no alterations were observed for the toxicity of the single pesticides. The results suggest that these analyses are important to evaluate pesticide toxicity mechanisms in ecological risk assessments of tropical regions. Thus, here we demonstrate the importance of using multiple parameters in ecotoxicological studies to obtain a better understanding of the toxicity of these compounds for phytoplankton. (AU) | |
| Processo FAPESP: | 15/18790-3 - Consequências ambientais da conversão pastagem-cana-de-açúcar e intensificação de pastagens |
| Beneficiário: | Luiz Antonio Martinelli |
| Modalidade de apoio: | Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Temático |
| Processo FAPESP: | 17/24126-4 - Efeitos dos pesticidas fipronil e 2,4-d isoladamente e em mistura, sobre espécies nativas da biota aquática neotropical |
| Beneficiário: | Raquel Aparecida Moreira |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 15/25436-1 - Influência de cobre e cádmio em alga e seus efeitos ecotoxicológicos em zooplâncton de água doce |
| Beneficiário: | Giseli Swerts Rocha |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |