Assessing the fate and effects of nano aluminum oxide in the terrestrial earthworm, Eisenia fetida

Abstract

Nano-sized aluminum is currently being used by the military and commercial industries in many applications including coatings, thermites, and propellants. Due to the potential for wide dispersal in soil systems, we chose to investigate the fate and effects of nano-sized aluminum oxide (Al2O3), the oxidized form of nano aluminum, in a terrestrial organism. The toxicity and bioaccumulation potential of micron-sized (50-200 microm, nominal) and nano-sized (11 nm, nominal) Al2O3 was comparatively assessed through acute and subchronic bioassays using the terrestrial earthworm, Eisenia fetida. Subchronic (28-d) studies were performed exposing E. fetida to nano- and micron-sized Al2O3-spiked soils to assess the effects of long-term exposure. No mortality occurred in subchronic exposures, although reproduction decreased at >or=3,000 mg/kg nano-sized Al2O3 treatments, with higher aluminum body burdens observed at 100 and 300 mg/kg; no reproductive effects were observed in the micron-sized Al2O3 treatments. In addition to toxicity and bioaccumulation bioassays, an acute (48-h) behavioral bioassay was conducted utilizing a soil avoidance wheel in which E. fetida were given a choice of habitat between control, nano-, or micron-sized Al2O3 amended soils. In the soil avoidance bioassays, E. fetida exhibited avoidance behavior toward the highest concentrations of micron- and nano-sized Al2O3 (>5,000 mg/kg) relative to control soils. Results of the present study indicate that nano-sized Al2O3 may impact reproduction and behavior of E. fetida, although at high levels unlikely to be found in the environment.

Metal‐based nanoparticles in soil: Fate, behavior, and effects on soil invertebrates

“…No mortality or reproductive effects (e.g., cocoon production, reproduction, cocoon hatchability) of Al 2 O 3 NPs on E. fetida were observed at 1,000 mg/kg [83]. Reproductive and behavioral effects of Al 2 O 3 NPs on E. fetida were found only at concentrations as high as 3,000 mg/kg and 10,000 mg/kg field soil (pH 7.0, containing 1% of organic matter), respectively [86]. The authors observed no mortality caused by NPs, although aluminum body concentration was greater in the earthworms exposed to NPs than in those exposed to microsized particles.…”

Emerging patterns for engineered nanomaterials in the environment: a review of fate and toxicity studies

“…A number of studies have indicated toxicity of ENMs to soil organisms as well as the ability for ENMs such as Au and Ag to enter terrestrial food webs and biomagnify (Benn and Westerhoff 2008;Judy et al 2011;Lowry et al 2012a, b). At high exposure concentrations, reproduction of E. fetida decreased for both Au and Al 2 O 3 (Coleman et al 2010;Unrine et al 2010). Along with harming reproduction in E. fetida, Ag was found to cause acute toxicity at 7.41 mg/kg in soil (Shoults-Wilson et al 2011).…”

Effects of aluminium oxide nanoparticles on bacterial growth

“…Only scarce information is available on fate, transport and effects in the environment of metal-based particles such as nano-Al 2 O 3 . Aluminum oxide NPs are currently used by the military and commercial industries as components of coatings and propellants and their widespread use may result in the release into the environment [19,20,21].…”