Nanomaterials (NMs) have gained prominence in technological advancements due to their tunable physical, chemical and biological properties with enhanced performance over their bulk counterparts. NMs are categorized depending on their size, composition, shape, and origin. The ability to predict the unique properties of NMs increases the value of each classification. Due to increased growth of production of NMs and their industrial applications, issues relating to toxicity are inevitable. The aim of this review is to compare synthetic (engineered) and naturally occurring nanoparticles (NPs) and nanostructured materials (NSMs) to identify their nanoscale properties and to define the specific knowledge gaps related to the risk assessment of NPs and NSMs in the environment. The review presents an overview of the history and classifications of NMs and gives an overview of the various sources of NPs and NSMs, from natural to synthetic, and their toxic effects towards mammalian cells and tissue. Additionally, the types of toxic reactions associated with NPs and NSMs and the regulations implemented by different countries to reduce the associated risks are also discussed.

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Review on nanoparticles and nanostructured materials: history, sources, toxicity and regulations.

Various stakeholders are increasingly interested in the potential toxicity and other risks associated with nanomaterials throughout the different stages of a product’s life cycle (e.g., development, production, use, disposal). Risk assessment methods and tools developed and applied to chemical and biological materials may not be readily adaptable for nanomaterials because of the current uncertainty in identifying the relevant physico-chemical and biological properties that adequately describe the materials. Such uncertainty is further driven by the substantial variations in the properties of the original material due to variable manufacturing processes employed in nanomaterial production. To guide scientists and engineers in nanomaterial research and application as well as to promote the safe handling and use of these materials, we propose a decision support system for classifying nanomaterials into different risk categories. The classification system is based on a set of performance metrics that measure both the toxicity and physico-chemical characteristics of the original materials, as well as the expected environmental impacts through the product life cycle. Stochastic multicriteria acceptability analysis (SMAA-TRI), a formal decision analysis method, was used as the foundation for this task. This method allowed us to cluster various nanomaterials in different ecological risk categories based on our current knowledge of nanomaterial physico-chemical characteristics, variation in produced material, and best professional judgments. SMAA-TRI uses Monte Carlo simulations to explore all feasible values for weights, criteria measurements, and other model parameters to assess the robustness of nanomaterial grouping for risk management purposes.

Risk-based classification system of nanomaterials

Sawdust--a green and economical sorbent for the removal of cadmium (II) ions.

Advances in nanoscale science and engineering suggest that many of the current problems involving water quality could be resolved or greatly improved using nanoparticles. Currently, the most widely used method for the removal and separation of toxic metal ions/organic compounds is the solid phase extraction technique. Recently, there have been reports in the literature on the enrichment and separation of trace elements and organic compound in the sample solutions by means of nanoparticles like TiO2, Al2O3, ZrO2, MnO and CeO2. Nanoparticles have unique properties like large specific surface area, high adsorption capacity and low temperature modification, so they are promising solid-phase extractants and have contaminant scavenging mechanisms. This feature article includes research work concerned with preparation, characterization and application of nanoparticles in preconcentration, separation and determination of trace pollutants from various environmental samples.

A review on applications of nanoparticles for the preconcentration of environmental pollutants

Characterisation of authentic Italian extra-virgin olive oils by stable isotope ratios of C, O and H and mineral composition

A new application of X-ray scattering using principal component analysis – classification of vegetable oils

A method for the determination of cadmium by flame atomic absorption spectrometry (FAAS) after its preconcentration onto a column containing silica gel modified with cupferron was developed The pH, amount of adsorbent material, concentration of eluent, volume of sample and amount of Cd were optimized The effect of several foreign ions was also investigated and showed that the retention of cadmium depended on the amounts of Zn(II) and Cu(II) present and that these interferences could be overcome by using a 005 mmol KI An enrichment factor of up to 30 was obtained , the LOD was 05 µg L-1 (3s) and the LOQ was 20 µg L-1 (10s) with rsd of 11% (n = 10) The accuracy of the proposed method was ascertained by using certified reference material and the obtained result (393 ± 001 µg g-1) agrees with the certified value (415 ± 038 µg g-1) The determination of Cd in nail polish showed quantitative recoveries for the spiked samples The proposed method is characterized by simplicity, efficiency and low cost

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Determination of cadmium by flame-atomic absorption spectrometry after preconcentration on silica gel modified with cupferron

Determination of total inorganic arsenic in water using on-line pre-concentration and hydride-generation atomic absorption spectrometry.

The first days of radioactivity, the discoveries of X-rays, radioactivity, of a- and b- particles and g- radiation, of new radioactive elements, of artificial radioactivity, the neutron and positron and nuclear fission are reviewed as well as several adverse historical marks, such as the Manhattan project and some nuclear and radiological accidents. Nuclear energy generation in Brazil and the world, as an alternative to minimize environmental problems, is discussed, as are the medicinal, industrial and food applications of ionizing radiation. The text leads the reader to reflect on the subject and to consider its various aspects with scientific and technological maturity.

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Gisele Gonçalves Bortoleto

Papers

A new application of X-ray scattering using principal component analysis – classification of vegetable oils

Determination of cadmium by flame-atomic absorption spectrometry after preconcentration on silica gel modified with cupferron

Determination of total inorganic arsenic in water using on-line pre-concentration and hydride-generation atomic absorption spectrometry.

Marcos da história da radioatividade e tendências atuais

X-ray scattering and multivariate analysis for classification of organic samples: a comparative study using Rh tube and synchrotron radiation.