Ecotoxicity and analysis of nanomaterials in the aquatic environment

Abstract

Nanotechnology is a major innovative scientific and economic growth area. However nanomaterial residues may have a detrimental effect on human health and the environment. To date there is a lack of quantitative ecotoxicity data, and recently there has been great scientific concern about the possible adverse effects that may be associated with manufactured nanomaterials. Nanomaterials are in the 1- to 100-nm size range and can be composed of many different base materials (carbon, silicon and metals, such as gold, cadmium and selenium) and they have different shapes. Particles in the nanometer size range do occur both in nature and as a result of existing industrial processes. Nevertheless, new engineered nanomaterials and nanostructures are different because they are being fabricated from the "bottom up". Nanomaterial properties differ compared with those of the parent compounds because about 40-50% of the atoms in nanoparticles (NPs) are on the surface, resulting in greater reactivity than bulk materials. Therefore, it is expected that NPs will have different biological effects than parent compounds. In addition, release of manufactured NPs into the aquatic environment is largely an unknown. The surface properties and the very small size of NPs and nanotubes provide surfaces that may bind and transport toxic chemical pollutants, as well as possibly being toxic in their own right by generating reactive radicals. This review addresses hazards associated and ecotoxicological data on nanomaterials in the aquatic environment. Main weaknesses in ecotoxicological approaches, controversies and future needs are discussed. A brief discussion on the scarce number of analytical methods available to determinate nanomaterials in environmental samples is included.

Potential scenarios for nanomaterial release and subsequent alteration in the environment

“…The use of CNT in composite matrices creates a much more durable product that can withstand physical and chemical processes [79], so this material will probably be altered at a slow rate. However, degradation processes of these materials have not been fully investigated, so altering the composite material and releasing CNT are difficult to evaluate [53].…”

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

“…In the environment, physical forces (e.g., Brownian motion, gravity, and fluid motion) and NP characteristics (e.g., surface properties, particle size) will affect NP agglomeration and aggregation [37]. The particles are constantly colliding with each other because of Brownian motion, and agglomeration will occur when the energy of either motion or attraction exceeds the energy of repulsion [38].…”

Analysis of engineered nanomaterials in complex matrices (environment and biota): General considerations and conceptual case studies

“…This method uses high-power ultrasonication to impart energy to the sample and effect transfer of PAHs into nonpolar organic solvents such as methylene chloride. Quantitative assays for fullerenes in environmental solid phases and tissues have also used ultrasonication for effective extraction of these materials into toluene [17][18][19][20]. Recoveries of fullerenes using these methods exceed 90%.…”