Environmental release, fate and ecotoxicological effects of manufactured ceria nanomaterials

Recent interest in the environmental fate and effects of manufactured CeO2 nanomaterials (nanoceria) has stemmed from its expanded use for a variety of applications including fuel additives, catalytic converters, chemical and mechanical planarization media and other uses. This has led to a wave 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. In this paper, we make initial estimates of likely environmental releases and exposure concentrations in soils and water and compare them to published toxicity values. Insufficient information was available to estimate aquatic exposures, but we estimated inputs to a hypothetical wastewater treatment plant that could result in effluent concentrations that would result in acute toxicity to the most sensitive aquatic organisms tested so far, cyanobacteria. The purpose of this exercise 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 recommend that future studies focus on environmentally realistic exposures that take into account potential environmental transformations of the nanoceria surface as well as chronic toxicity studies in benthic aquatic organisms, soil invertebrates and microorgansims

Release of engineered nanomaterials from personal care products throughout their life cycle

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 (TiO2), 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 TiO2 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. © 2014 Springer Science+Business Media

Predicted Releases of Engineered Nanomaterials: From Global to Regional to Local

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 ENM-containing 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

Estimating Potential Life Cycle Releases of Engineered Nanomaterials from Wastewater Treatment Plants

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

Simulation tool for assessing the release and environmental distribution of nanomaterials.

An 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

Simulation tool for assessing the release and environmental distribution of nanomaterials.

An 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

Calculation of a uniform gas ow from the heated tungsten plate surface

At INP SB RAS, various mechanisms for the erosion of tungsten samples during the pulsed heating were studied. Data were obtained that made it possible to analyze the experimental results of the surface temperature dynamics taking into account the cooling due to the vaporation in vacuum. A numerical model was developed for the effect of a powerful pulsed electron beam on tungsten, which includes the Stefan problem for determining the temperature distribution in a sample and the system of gas dynamics equations. The gas dynamics system is implemented by the two methods of first order of accuracy: the upwind scheme and Belotserkovsky's coarse particle method. For the program veri cation, a test solution of the gas decay was used. In the process of calculating the problem in a complete statement, an analysis of the residual was carried out

Establishing Normative Values to Determine the Prevalence of Biochemical Hyperandrogenism in Premenopausal Women of Different Ethnicities from Eastern Siberia

Androgen assessment is a key element for diagnosing polycystic ovary syndrome (PCOS), and defining a “normal” level of circulating androgens is critical for epidemiological studies. We determined the upper normal limits (UNLs) for androgens in a population-based group of premenopausal “healthy control” women, overall and by ethnicity (Caucasian and Asian), in the cross-sectional Eastern Siberia PCOS Epidemiology and Phenotype (ESPEP) Study (ClinicalTrials.gov ID: NCT05194384) conducted in 2016–2019. Overall, we identified a “healthy control” group consisting of 143 healthy premenopausal women without menstrual dysfunction, hirsutism, polycystic ovaries, or medical disorders. We analyzed serum total testosterone (TT) by using liquid chromatography with tandem mass spectrometry (LC-MS/MS), and DHEAS, sex-hormone-binding globulin (SHBG), TSH, prolactin, and 17-hydroxyprogesterone (17OHP) were assessed with an enzyme-linked immunosorbent assay (ELISA). The UNLs for the entire population for the TT, free androgen index (FAI), and DHEAS were determined as the 98th percentiles in healthy controls as follows: 67.3 (95% confidence interval (CI): 48.1, 76.5) ng/dl, 5.4 (3.5, 14.0), and 355 (289, 371) μg/dl, respectively. The study results demonstrated that the UNLs for TT and FAI varied by ethnicity, whereas the DHEAS UNLs were comparable in the ethnicities studied