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

Abstract

Abstract-Metal-based nanoparticles (NPs) (e.g., silver, zinc oxide, titanium dioxide, iron oxide) are being widely used in the nanotechnology industry. Because of the release of particles from NP-containing products, it is likely that NPs will enter the soil compartment, especially through land application of sewage sludge derived from wastewater treatment. This review presents an overview of the literature dealing with the fate and effects of metal-based NPs in soil. In the environment, the characteristics of NPs (e.g., size, shape, surface charge) and soil (e.g., pH, ionic strength, organic matter, and clay content) will affect physical and chemical processes, resulting in NP dissolution, agglomeration, and aggregation. The behavior of NPs in soil will control their mobility and their bioavailability to soil organisms. Consequently, exposure characterization in ecotoxicological studies should obtain as much information as possible about dissolution, agglomeration, and aggregation processes. Comparing existing studies is a challenging task, because no standards exist for toxicity tests with NPs. In many cases, the reporting of associated characterization data is sparse, or missing, making it impossible to interpret and explain observed differences in results among studies. Environ. Toxicol. Chem.

Metal and nanoparticle occurrence in biosolid-amended soils

“…The land application of biosolids is currently subject to several metal concentration limits according to the U.S. EPA Part 503 Biosolids Rule, including those for arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), molybdenum (Mo), nickel (Ni), selenium (Se), and zinc (Zn) (U.S. EPA, 1995). However, despite their widespread use in industry, less information exists on classically unregulated metals (e.g., minor metals, MMs) or rare earth elements (REEs), and metals associated with nanomaterials (Chang et al, 1984;Graedel and Van Der Voet, 2010;Han et al, 2000;Jorg et al, 1999;Tourinho et al, 2012). Engineered nanomaterials (ENMs) that are discharged to sewers and accumulate in biosolids could eventually end up in soils amended with those biosolids (de la Rosa et al, 2011;Judy et al, 2012;Kim et al, 2012).…”

Influence of soil pH on the toxicity of zinc oxide nanoparticles to the terrestrial isopod Porcellionides pruinosus

“…The ZnO NPs are used mainly in cosmetics (as UV absorbants in sunscreens), paints, and coatings [3]. The use of NPs may result in emissions into the environment, with soil being an important sink [4].…”

“…Some attention has been paid to the behavior and effects of NPs in the environment [4]. The processes of dissolution and aggregation or agglomeration have been shown to be dependent on characteristics of both the exposure media and the NPs.…”

“…The stability of ZnO NPs is affected by environmental conditions such as pH [5], organic matter content [6], and ionic strength [7]. In soils, pH is one of the most important factors to consider in toxicity tests, because it can change the NP surface charge and zeta potential [4]. As a consequence, the interactions between NPs and soil, as well as the interactions between particles, will change, influencing NP behavior, bioavailability, and toxicity.…”

Toxicity of ZnO Nanoparticles, ZnO Bulk, and ZnCl2 on Earthworms in a Spiked Natural Soil and Toxicological Effects of Leachates on Aquatic Organisms

“…Regarding organisms, more information is available about freshwater receptors compared with organisms that live in the soil (Kahru and Dubourguier 2010). In general, this information focuses on tests of acute toxicity (Tourinho et al 2012;Li et al 2011), thus leaving a gap (with some exceptions) in the knowledge about potential long-term effects (Kool et al 2011;Manzo et al 2011).…”