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A key question for industry, regulators, toxicologists, and risk assessors working with nanomaterials is what relevant environmental engineered nanomaterial (ENM) concentrations should be considered. Answering this question requires ENM material flow estimates at the local level. Using a life-cycle approach, global ENM production and application data were used to estimate releases at global, regional, national, and local levels. Local level emissions were then used to estimate releases to water (direct and from wastewater treatment effluent), soils (direct and from runoff and biosolids), and air (direct and from incineration of ENMcontaining products). Waste management data for dozens of countries were used to estimate the flow of 10 major ENMs through eight world regions. A national and local release example was conducted with data from the United States, providing predicted wastewater effluent concentrations for the San Francisco Bay area, ranging from low nanograms per liter to micrograms per liter depending on the ENM.

In the absence of experimental data, a life cycle modeling approach can be used to predict engineered nanomaterial (ENM) concentrations in environmental media. Several such models have been created with various geographic scopes. This study presents an environmental release model that accounts for local differences in product consumption, wastewater treatment levels, waste incineration, and biosolids management and provides estimates of ENM release from wastewater treatment facilities in New York City, London, and Shanghai. The results illustrate how these local variations in model parameters contribute to differences in predicted ENM concentration in wastewater effluent and biosolids on a local level. Our analysis also takes a first step toward conducting a local-level risk assessment by providing the approximate locations and quantities of ENM discharge into aquatic systems. We find that there is significant uncertainty in model parameters that leads to a wide range of concentration estimates, yet we find that local variations in model parameters predict ENM concentration estimates that are within the same order of magnitude.

uses. This has led to a number of publications on the toxicological effects of nanoceria in ecological receptor species, but only limited information is available on possible environmental releases, concentrations in environmental media, or environmental transformations. Increasing material flows of nanoceria in many applications is likely to result in increasing releases to air, water and soils however; insufficient information was available to estimate aquatic exposures that would result in acute or chronic toxicity. The purpose of this review is to identify which areas are lacking in data to perform either regional or site specific ecological risk assessments. While estimates can be made for releases from use as a diesel fuel additive, and predicted toxicity is low in most terrestrial species tested to date, estimates for releases from other uses are difficult at this stage. We

The impetus for this study was to provide release estimates that can serve to improve predictions of engineered nanomaterial (ENM) exposure for risk assessment. We determined the likely release of ENMs from personal care products (PCPs) through a consumer survey on use and disposal habits, and research on the types and quantities of ENMs in PCPs. Our estimates show that in the US zinc oxide (ZnO), with 1,800-2,100 mt yr -1 , and titanium dioxide (TiO 2 ), with 870-1,000 mt yr -1 , represent 94 % of ENMs released into the environment or landfills from the use of PCPs. Around 36-43 % of ENMs from PCPs were estimated to end up in landfills, 24-36 % released to soils, 0.7-0.8 % to air, and 28-32 % to water bodies. ENMs in sunscreen represent around 81-82 % of total release, from ZnO and TiO 2 as UV blockers, followed by facial moisturizer (7.5 %), foundation (5.7 %), and hair coloring products (3.1 %). Daily care products such as body wash, shampoo, and conditioner had by far the highest per capita and total use, but contributed little to the ENM release estimates as these products generally contain little or no ENMs. However, if ENMs are incorporated into these daily care products, this may substantially increase ENM release.

SummaryAn integrated simulation tool was developed for assessing the potential release and environmental distribution of nanomaterials (RedNano) based on a life cycle assessment approach and multimedia compartmental modeling coupled with mechanistic intermedia transport processes. The RedNano simulation tool and its web-based software implementation enables rapid “what-if?” scenario analysis, in order to assess the response of an environmental system to various release scenarios of engineered nanomaterials (ENMs). It also allows for the investigation of the impact of geographical and meteorological parameters on ENM distribution in the environment, comparison of the impact of ENM production and potential releases on different regions, and estimation of source release rates based on monitored ENM concentrations. Moreover, the RedNano simulation tool is suitable for research, academic, and regulatory purposes. Specifically, it has been used in environmental multimedia impact assessment courses at both the undergraduate and graduate levels. The RedNano simulation tool can also serve as a decision support tool to rapidly and critically assess the potential environmental implications of ENMs and thus ensure that nanotechnology is developed in a productive and environmentally responsible manner.

An integrated modeling platform was developed for assessing the potential release rates of ENMs and their environmental distribution. ENM release rates are estimated via life cycle assessment based approach by tracking the target ENM throughout its life cycle from production to release to the environment. Potential ENM exposure concentrations and mass distribution in the various environmental media (i.e., air, water soil, vegetation) are then evaluated via multimedia modeling that considers the environment as a collection of compartments linked by mechanistic intermedia transport processes. A web-based software implementation of the modeling platform enables rapid "what-if?" scenario analysis, which can be used to assess the response of environmental system to various scenarios of ENM releases, investigate the impact of geographical and meteorological parameters on ENM distribution in the environment, compare the impact of ENM production and potential releases on different regions, we well as estimate source release rates based on monitored ENM concentrations. Moreover, the present modeling platform is suitable for research and teaching regarding environmental multimedia impact assessment at both the undergraduate and graduate levels. It is envisioned that the present multimedia analysis platform can assist regulators, industry, and researchers to rapidly and critically assess the potential environmental implications of ENMs and thus ensure that nanotechnology is developed in a productive and environmentally responsible manner.

Mechanical engineering is the leading business unit, capable of giving impetus to innovation development of all industry sectors virtually, so restructuring and development of innovative production in engineering industry is an objective and urgent problem of modern times.