title: Effect of PFOA/PFOS pre-exposure on the toxicity of the herbicides 2,4-D, Atrazine, Diuron and Paraquat to a model aquatic photosynthetic microorganism.
abstract: Pre-exposure to the perfluorinated compounds (PFCs) perfluorooctano sulphonate (PFOS) or perfluorooctanoic acid (PFOA) on the toxicity of four herbicides of different types and modes of action towards the self-luminescent recombinant cyanobacterium Anabaena CPB4337 was evaluated. The rationale of the approach is that both PFOS and PFOA as surfactants are known to modify cell membrane properties and pre-exposure to them might alter herbicide toxicity towards the cyanobacterium. Anabaena CPB4337 was pre-exposed during 72h to PFOS or PFOA at a concentration below their no observed effect concentration (NOEC). After pre-exposure, cells were exposed to increasing concentrations of 2,4-D Atrazine, Diuron and Paraquat and the toxicity was compared to that of non-pre-exposed ones. The data clearly showed that PFCs pre-treatment significantly altered the toxicity of the tested herbicides. However the effects resulting from PFOA and PFOS pre-exposure were not homogeneous for all the herbicides. In general PFOA pre-exposure resulted in increased herbicide toxicity except for atrazine, while PFOS pre-exposure resulted in increased toxicity for paraquat and diuron, and reduced toxicity for atrazine with no significant effect on 2,4-D toxicity. The strongest modifying effect was found for paraquat whose toxicity doubled with PFOA pre-exposure. Further analysis of membrane properties by flow cytometry revealed that both PFOA and PFOS were able to modify membrane integrity and membrane potential of Anabaena CPB4337 at the concentrations used in the pre-exposure experiments. These results reveal relevant indirect effects of PFCs pollution with eco-toxicological implications.
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Ismael
authors.initials: I
authors.lastname: Rodea-Palomares
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Marcin
authors.initials: M
authors.lastname: Makowski
authors.affiliation: Departamento de Ingeniería Química, Universidad de Alcalá, E-28871, Alcalá de Henares, Madrid, Spain.
authors.forename: Soledad
authors.initials: S
authors.lastname: Gonzalo
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Miguel
authors.initials: M
authors.lastname: González-Pleiter
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain.
authors.forename: Francisco
authors.initials: F
authors.lastname: Leganés
authors.affiliation: Departamento de Biología, Facultad de Ciencias, Universidad Autónoma de Madrid, E-28049 Madrid, Spain. Electronic address: francisca.pina@uam.es.
authors.forename: Francisca
authors.initials: F
authors.lastname: Fernández-Piñas
mesh_terms: D015084:2,4-Dichlorophenoxyacetic Acid / Q000633:toxicity; D017738:Alkanesulfonic Acids / Q000633:toxicity*; D017033:Anabaena / Q000187:drug effects; D001280:Atrazine / Q000633:toxicity; D002210:Caprylates / Q000633:toxicity*; D002462:Cell Membrane / Q000187:drug effects; D004237:Diuron / Q000633:toxicity; D004357:Drug Synergism; D005466:Fluorocarbons / Q000633:toxicity*; D006540:Herbicides / Q000633:toxicity*; D010269:Paraquat / Q000633:toxicity; D010788:Photosynthesis
chemical_list: D017738:Alkanesulfonic Acids; D002210:Caprylates; D005466:Fluorocarbons; D006540:Herbicides; D015084:2,4-Dichlorophenoxyacetic Acid; C023036:perfluorooctanoic acid; C076994:perfluorooctane sulfonic acid; D004237:Diuron; D010269:Paraquat; D001280:Atrazine
keywords: Bioluminescence inhibition; Cyanobacteria; Herbicide toxicity; Membrane alterations; PFCs; Pre-exposure