TiO₂ Nanoparticles in the Marine Environment: Impact on the Toxicity of Tributyltin to Abalone (Haliotis diversicolor supertexta) Embryos

Abstract

Little information is available on the potential ecotoxicity of manufactured nanomaterials (MNMs) in the marine environment. To carefully address this issue, the toxicity of nanosized titanium dioxide (nTiO(2)) aggregates in the marine environment was evaluated using abalone (Haliotis diversicolor supertexta) embryonic development as a model. The effect of nTiO(2) aggregates on the toxicity of the highly toxic marine antifouling compound tributyltin (TBT) to abalone embryos was also investigated. No developmental effects of nTiO(2) were observed at 2 mg/L but concentrations ≥10 mg/L caused hatching inhibition and malformations. The presence of 2 mg/L nTiO(2) increased the toxicity of TBT up to 20-fold compared with TBT alone. This enhancement of TBT may be due to the combined effects of TBT adsorption onto nTiO(2) aggregates and the internalization of nTiO(2) aggregates by abalone embryos. These observations indicate that MNMs may have important indirect impacts on aquatic organisms by varying the toxicity of coexisting pollutants. Thus, risk assessments for MNMs should consider both their direct effects and possible indirect effects of interactions with other environmental contaminants.

Cell Rescue by Nanosequestration: Reduced Cytotoxicity of An Environmental Remediation Residue, Mg(OH)2 Nanoflake/Cr(VI) Adduct

“…22 The tributyltin/nano-TiO 2 adduct is more toxic to abalone embryos than tributyltin alone. 23 Similar synergistic toxicities to aquatic organisms have also been found for As, Pb, Cu, and Cd in the presence of nano-Al 2 O 3 , nanoFe 2 O 3 , and nano-TiO 2 . 24−28 Recently, we have observed significant research efforts exerted toward the investigation of nanoparticle toxicity.…”

Effect of titanium dioxide nanoparticles on the bioavailability, metabolism, and toxicity of pentachlorophenol in zebrafish larvae

“…In contrast, several previous studies have reported enhanced bioavailability of organic toxicants to exposure organisms (e.g., tributyltin, BDE-209, DDT, TCDD) in the presence of n-TiO 2 [12,13,45,46], as n-TiO 2 acted as a carrier that enables compounds to adsorb on the organism surface. At the same time, adsorption and sedimentation also normally occurred in organic toxicants with n-TiO 2 in exposure media [12,46,51]. Thus, sedimentation does not appear to be the major reason that affects the bioavailability of organic toxicants by organisms.…”

“…Previous studies have reported that n-TiO 2 can adsorb heavy metals [4,34,44] or organic toxicants, including tributyltin, PBDEs, DDT and tetrachlorodibenzo-p-dioxin [TCDD] [12,13,45,46], while study showed the aggregation and subsequent sedimentation of nTiO 2 with tributyltin [12]. At the same time, we did not measure and (E) GSH content in larvae after exposure to PCP alone (0, 3, 10, and 30 g/L) and in the presence of n-TiO2 (0.1 mg/L) for 6 days.…”

“…The n-TiO 2 exposure concentration was based on our previous findings: after exposure to this n-TiO 2 concentration (0.1 mg/L), neither developmental toxicity nor oxidative stress was observed in zebrafish larvae [13]. A previous study also indicated that exposure to nTiO 2 (20 nm; up to 500 mg/L; during 96 h exposure) neither affected hatching nor induced deformity in zebrafish embryos [12]. In addition, with the increased production and application of n-TiO 2 , levels of n-TiO 2 in the environment are expected to increase, and also because of their persistent properties, 0.1 mg/L n-TiO 2 is in the same order of magnitude to the environmental concentration (predicted as 16 g/L in Switzerland) [36].…”

“…In this regard, NPs are highly insoluble and have a large surface area to volume ratio, suggesting that they are likely to interact with other substances in water [2][3][4]. Thus, NPs organic contaminants and enhances the uptake of organic pollutants (e.g., tributyltin, polybrominated diphenyl ethers [PBDEs]) in organisms [12,13]. Importantly, n-TiO 2 are one of the commonest materials used to degrade organic compounds, mainly on their photocatalytic activity at the absorption of ultraviolet (UV) light at specific wavelengths (especially at 300-388 nm), via generation of reactive oxygen species (ROS) that can cause decomposition of organic molecules [14][15][16].…”