title: Impact of organic nano-vesicles in soil: The case of sodium dodecyl sulphate/didodecyl dimethylammonium bromide.
abstract: Aiming at contributing new insights into the effects of nanomaterials (NMs) in the terrestrial ecosystem, this study evaluated the impacts of organic nano-vesicles of sodium dodecyl sulphate/didodecyl dimethylammonium bromide (SDS/DDAB) on the emergence and growth of plant seeds, and on the avoidance and reproduction of soil invertebrates. For this purpose several ecotoxicological assays were performed with different test species (terrestrial plants: Zea mays, Avena sativa, Brassica oleracea and Lycopersicon esculentum; soil invertebrates: Eisenia andrei and Folsomia candida). A wide range of SDS/DDAB concentrations were tested, following standard protocols, and using the standard OECD soil as a test substrate (5% of organic matter). The aqueous suspensions of SDS/DDAB, used to spike the soils, were characterised by light scattering techniques for hydrodynamic size of the vesicles, aggregation index, polydispersity index, zeta potential and surface charge. The SDS/DDAB concentrations in the test soil were analysed by HPLC-UV at the end of the assays. Invertebrate species were revealed to be sensitive to nano-SDS/DDAB upon immediate exposure to freshly spiked soils. However, the degradation of SDS/DDAB nano-vesicles in the soil with time prevented the occurrence of significant reproduction effects on soil invertebrates. Plants were not particularly sensitive to SDS/DDAB, except B. oleracea (at concentrations above 375 mg kg(-1)dw). The results gathered in this study allowed a preliminary determination of a risk limit to nano-SDS/DDAB. The low toxicity of SDS/DDAB nano-vesicles could be explained by its high and fast degradation in the soil. The soil microbial community could have an important role in the fate of this NM, thus it is of remarkable importance to improve this risk limit by taking into account specific data addressing this community.
authors.affiliation: Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal; CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, n. 289, 4050-123 Porto, Portugal. Electronic address: up201310026@fc.up.pt.
authors.forename: A
authors.initials: A
authors.lastname: Gavina
authors.affiliation: Laboratory of Water, Energy and Environment (3E), Engineering School of Sfax, University of Sfax, BPW 3038 Sfax, Tunisia.
authors.forename: S
authors.initials: S
authors.lastname: Bouguerra
authors.affiliation: Department of Biology & Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: I
authors.initials: I
authors.lastname: Lopes
authors.affiliation: Department of Biology & Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: C R
authors.initials: CR
authors.lastname: Marques
authors.affiliation: Department of Chemical Engineering & Chemical Process Engineering and Forest Products Research Centre (CIEPQPF), University of Coimbra, 3030-290 Coimbra, Portugal.
authors.forename: M G
authors.initials: MG
authors.lastname: Rasteiro
authors.affiliation: Department of Chemical Engineering & Chemical Process Engineering and Forest Products Research Centre (CIEPQPF), University of Coimbra, 3030-290 Coimbra, Portugal.
authors.forename: F
authors.initials: F
authors.lastname: Antunes
authors.affiliation: Department of Chemistry & Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus de Santiago, 3810-193 Aveiro, Portugal.
authors.forename: T
authors.initials: T
authors.lastname: Rocha-Santos
authors.affiliation: Department of Biology, Faculty of Sciences of the University of Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal; CIIMAR - Interdisciplinary Centre of Marine and Environmental Research, Rua dos Bragas, n. 289, 4050-123 Porto, Portugal.
authors.forename: R
authors.initials: R
authors.lastname: Pereira
mesh_terms: D000818:Animals; D001681:Biological Assay; D054750:Ecotoxicology; D049329:Nanostructures / Q000633:toxicity*; D009835:Oligochaeta; D010944:Plants; D000644:Quaternary Ammonium Compounds / Q000633:toxicity*; D012967:Sodium Dodecyl Sulfate / Q000633:toxicity*; D012987:Soil; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D000644:Quaternary Ammonium Compounds; D012987:Soil; D012989:Soil Pollutants; C046112:didodecyldimethylammonium; D012967:Sodium Dodecyl Sulfate
keywords: Avoidance; Organic nanomaterials; PNEC value; Plant growth; Reproduction; Seed emergence; Soil invertebrates