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Abstract The rapid proliferation of many different engineered nanomaterials (defined as materials designed and produced to have structural features with at least one dimension of 100 nanometers or less) presents a dilemma to regulators regarding hazard identification. The International Life Sciences Institute Research Foundation/Risk Science Institute convened an expert working group to develop a screening strategy for the hazard identification of engineered nanomaterials. The working group report presents the elements of a screening strategy rather than a detailed testing protocol. Based on an evaluation of the limited data currently available, the report presents a broad data gathering strategy applicable to this early stage in the development of a risk assessment process for nanomaterials. Oral, dermal, inhalation, and injection routes of exposure are included recognizing that, depending on use patterns, exposure to nanomaterials may occur by any of these routes. The three key elements of the toxicity screening strategy are: Physicochemical Characteristics, In Vitro Assays (cellular and non-cellular), and In Vivo Assays. There is a strong likelihood that biological activity of nanoparticles will depend on physicochemical parameters not routinely considered in toxicity screening studies. Physicochemical properties that may be important in understanding the toxic effects of test materials include particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity. In vitro techniques allow specific biological and mechanistic pathways to be isolated and tested under controlled conditions, in ways that are not feasible in in vivo tests. Tests are suggested for portal-of-entry toxicity for lungs, skin, and the mucosal membranes, and target organ toxicity for endothelium, blood, spleen, liver, nervous system, heart, and kidney. Non-cellular assessment of nanoparticle durability, protein interactions, complement activation, and pro-oxidant activity is also considered. Tier 1 in vivo assays are proposed for pulmonary, oral, skin and injection exposures, and Tier 2 evaluations for pulmonary exposures are also proposed. Tier 1 evaluations include markers of inflammation, oxidant stress, and cell proliferation in portal-of-entry and selected remote organs and tissues. Tier 2 evaluations for pulmonary exposures could include deposition, translocation, and toxicokinetics and biopersistence studies; effects of multiple exposures; potential effects on the reproductive system, placenta, and fetus; alternative animal models; and mechanistic studies.

The article examines the U.S.' National Nanotechnology Initiative proposed by scientist Mihail Roco and endorsed by President Bill Clinton, dealing with topics including the efforts to incorporate environment, health, and safety procedures at various development stages and nanotechnology's history.

The development of environmentally benign methods for the synthesis of nanomaterials has become increasingly relevant as chemists look to shape a more sustainable future. In this critical review, we present current work towards developing alternative methods for synthesizing a wide range of high-quality nanomaterials with predictable and controllable size, shape, composition, morphology and crystallinity. In particular, we focus on the inherent advantages of utilizing porous membrane templates, ultrasonic and microwave irradiation, alternative solvent systems, as well as biologically-inspired reagents as reasonably cost-effective, environmentally responsible methods to generate metal, metal oxide, fluoride, sulfide, selenide and phosphate nanomaterials. [ABSTRACT FROM AUTHOR]

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The article considers sustainability issues involved in using green nanotechnology. The U.S. previously addressed environmental, health and safety (EHS) issues associated with using nanotechnology in 2006. The result was the emergence of the concept of green nanotechnology, which attempts to produce nanomaterials and products that do not harm the environment or human health, as well as to produce nanoproducts that provide solutions to environmental challenges. A key aspect to achieving these goals is ensuring sustainability in all stages of the life cycle.

The rapid proliferation of many different engineered nanomaterials (defined as materials designed and produced to have structural features with at least one dimension of 100 nanometers or less) presents a dilemma to regulators regarding hazard identification. The International Life Sciences Institute Research Foundation/Risk Science Institute convened an expert working group to develop a screening strategy for the hazard identification of engineered nanomaterials. The working group report presents the elements of a screening strategy rather than a detailed testing protocol. Based on an evaluation of the limited data currently available, the report presents a broad data gathering strategy applicable to this early stage in the development of a risk assessment process for nanomaterials. Oral, dermal, inhalation, and injection routes of exposure are included recognizing that, depending on use patterns, exposure to nanomaterials may occur by any of these routes. The three key elements of the toxicity screening strategy are: Physicochemical Characteristics, In Vitro Assays (cellular and non-cellular), and In Vivo Assays. There is a strong likelihood that biological activity of nanoparticles will depend on physicochemical parameters not routinely considered in toxicity screening studies. Physicochemical properties that may be important in understanding the toxic effects of test materials include particle size and size distribution, agglomeration state, shape, crystal structure, chemical composition, surface area, surface chemistry, surface charge, and porosity. In vitro techniques allow specific biological and mechanistic pathways to be isolated and tested under controlled conditions, in ways that are not feasible in in vivo tests. Tests are suggested for portal-of-entry toxicity for lungs, skin, and the mucosal membranes, and target organ toxicity for endothelium, blood, spleen, liver, nervous system, heart, and kidney. Non-cellular assessment of nanoparticle durability, protein interactions, complement activation, and pro-oxidant activity is also considered. Tier 1 in vivo assays are proposed for pulmonary, oral, skin and injection exposures, and Tier 2 evaluations for pulmonary exposures are also proposed. Tier 1 evaluations include markers of inflammation, oxidant stress, and cell proliferation in portal-of-entry and selected remote organs and tissues. Tier 2 evaluations for pulmonary exposures could include deposition, translocation, and toxicokinetics and biopersistence studies; effects of multiple exposures; potential effects on the reproductive system, placenta, and fetus; alternative animal models; and mechanistic studies. [ABSTRACT FROM AUTHOR]

gThe article focuses on the challenges and opportunities in the field of nanoscale environmental science and technology. The technical and popular literature is chock-full of discoveries of novel physical, chemical, and biological properties associated with materials whose dimensions are in the nanoscale domain. Insofar as environmental applications are concerned, nanomaterials offer the promise of novel materials and processes exhibiting enhanced reactivity toward targeted contaminants, better mobility in environmental media, and easier deployment.

Nanotechnology offers immense promise for developing new technologies that are more sustainable than current technologies. All major industrial sectors have felt nanotechnology's impact, mainly from the incorporation of nanomaterials into their products. For example, nanotechnology has improved the design and performance of products in areas as diverse as electronics, medicine and medical devices, food and agriculture, cosmetics, chemicals, materials, coatings, energy, as well as many others. Moreover, the revenues from nanotechnology-enabled products are not trivial. For instance, Lux Research maintains that commercial sales in both Europe and the USA will attain revenues of over $1 trillion from nano-enabled products by 2015. The manufacturing of the nanomaterials for these products uses many processes equivalent to chemical manufacturing processes. As a result, manufacturing nanomaterials can produce either harmful pollutants or adverse environmental impacts similar to those from chemical manufacturing. Unlike the chemical industry, however, those same processes are not ingrained in the manufacturing of nanomaterials, and the opportunity exists at the initial design stage to purposely account for and mitigate out potentially harmful environmental impacts. While prevention has not been a priority in current industries, it can become a main concern for the new and future industries that manufacture nanomaterials on a bulk commercial scale. This is where green nanotechnology comes in. Green nanotechnology involves deliberate efforts aimed at developing meaningful and reasonable protocols for generating products and their associated production processes in a benign fashion. The goal is a conscious minimization of risks associated with the products of nanoscience. The green products of nanotechnology are those that are used in either direct or indirect environmental applications. Direct environmental applications provide benefits such as monitoring using nano-enabled sensors, remediation of hazardous waste sites with nanomaterials, or treatment of wastewater and drinking water with nanomaterials. Indirect environmental applications include, for example, the saved energy associated with either lighter nanocomposite materials in transport vehicles or reduced waste from smaller products. The production and process aspects of green nanotechnology involve both making nanomaterials in a more environmentally benign fashion and using nanomaterials to make current chemical processes more environmentally acceptable. Examples of producing nanomaterials in a 'greener manner' could involve but are not limited to the use of supercritical CO2, water, or ionic liquids to replace a volatile organic solvent. Either self-assembly or templating might also be used to eliminate waste in manufacturing. Renewables could be utilized as replacements for either nonrenewable and/or toxic starting materials. Microwave techniques might potentially help to conserve energy, as could both facile thermal and hydrothermal processes. Catalytic and photocatalytic reactions could also increase efficiency and decrease the formation of harmful byproducts. In addition, engineered nanomaterials themselves can be used as catalysts in current chemical processes and as separation membranes to aid in the efficiency of these operations. Furthermore, in order to be truly green, these products and processes must be considered within a lifecycle framework. The papers in this special issue are but a small sampling of the myriad of possibilities that green nanotechnology holds. In the nascent nanotechnology industry, green nanotechnology offers the opportunity to get it right in the first place. It is not too late to take Ben Franklin's words to heart, 'an ounce of prevention is worth a pound of cure'. [ABSTRACT FROM AUTHOR]

Rare earth elements and several metals formerly uncommon in commerce are being introduced into new products, particularly as nanoscaled materials. Until recently, little attention has been paid to their sustainability issues. This perspective addresses these elements, their commercial uses, health and environment issues, sustainability, and suggests a path forward.

In this review, we focus on environmental cleanup and provide a background and overview of current practice; research findings; societal issues; potential environment, health, and safety implications; and future directions for nanoremediation. We also discuss nanoscale zero-valent iron in detail. We searched the Web of Science for research studies and accessed recent publicly available reports from the U.S. Environmental Protection Agency and other agencies and organizations that addressed the applications and implications associated with nanoremediation techniques. We also conducted personal interviews with practitioners about specific site remediations. We aggregated information from 45 sites, a representative portion of the total projects under way, to show nanomaterials used, types of pollutants addressed, and organizations responsible for each site. Nanoremediation has the potential not only to reduce the overall costs of cleaning up large-scale contaminated sites but also to reduce cleanup time, eliminate the need for treatment and disposal of contaminated soil, and reduce some contaminant concentrations to near zero--all in situ.