Acute exposure to C60 fullerene damages pulmonary mitochondrial function and mechanics.

C60 fullerene (C60) nanoparticles, a nanomaterial widely used in technology, can offer risks to humans, overcome biological barriers, and deposit onto the lungs. However, data on its putative pulmonary burden are scanty. Recently, the C60 interaction with mitochondria has been described in vitro and in vivo. We hypothesized that C60 impairs lung mechanics and mitochondrial function. Thirty-five male BALB/c mice were randomly divided into two groups intratracheally instilled with vehicle (0.9% NaCl + 1% Tween 80, CTRL) or C60 (1.0 mg/kg, FUL). Twenty-four hours after exposure, 15 FUL and 8 CTRL mice were anesthetized, paralyzed, and mechanically ventilated for the determination of lung mechanics. After euthanasia, the lungs were removed en bloc at end-expiration for histological processing. Lung tissue elastance and viscance were augmented in FUL group. Increased inflammatory cell number, alveolar collapse, septal thickening, and pulmonary edema were detected. In other six FUL and six CTRL mice, mitochondria expressed reduction in state 1 respiration [FUL = 3.0 ± 1.14 vs. CTRL = 4.46 ± 0.9 (SEM) nmol O2/min/mg protein, p = 0.0210], ATP production (FUL = 122.6 ± 18 vs. CTRL = 154.5 ± 14 µmol/100 µg protein, p = 0.0340), and higher oxygen consumption in state 4 [FUL = 12.56 ± 0.9 vs. CTRL = 8.26 ± 0.6], generation of reactive oxygen species (FUL 733.1 ± 169.32 vs. CTRL = 486.39 ± 73.1 nmol/100 µg protein, p = 0.0313) and reason ROS/ATP [FUL = 8.73 ± 2.3 vs. CTRL = 2.99 ± 0.3]. In conclusion, exposure to fullerene C60 impaired pulmonary mechanics and mitochondrial function, increased ROS concentration, and decrease ATP production.

Understanding the mobility of potential nutrients in rock mining by-products: An opportunity for more sustainable agriculture and mining.

The increase in demand for highly soluble fertilizers brings a global sustainability concern. Alternative sources for traditional fertilization are therefore needed. Rock powder use has been proposed as an alternative approach to soil remineralization. However, research on the agricultural potential of minerals and rocks as alternative sources of nutrients is limited to changes in soil chemical attributes or effects on crop yield. In this work, we report an experimental study addressing the dissolution of two silicate rock-derived powders (andesite and dacite) that were produced during mining activities in Southern Brazil. The rock powders were exposed to Milli-Q water at pH (7.4-8.8) range, in solutions of 0.1 mol L-1 citric acid at pH range 2.1-3.3, and Milli-Q water acidified with 0.5 mol l-1 acetic acid (pH 5-5.8), in a continuous mechanical rotatory shaker at room temperature. Dissolution kinetics were determined as a function of reaction times at 24 to 5760 h, and solution pH. Based on this kinetics, dissolution rates were determined for the individual powders and compared to expected values for aluminosilicates. Based on this comparison, it was shown that the application of andesite and dacite rock-derived powder to replace high soluble fertilizers is feasible due to high dissolution rates of their minerals. The average andesite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 2.1 × 10-5, 1.92 × 10-1 and 6.3 × 10-4 mmol cm-2 s-1, respectively for Ca, being 183%, 22.6%, and 69.2% higher than for the dacite rock. This make andesite rock a potential substitute for carbonate-based liming. In contrast, the average dacite dissolution rates in Milli-Q water, in citric acid solution, and in Milli-Q water acidified with acetic acid were 1.05 × 10-5, 7.22 × 10-5, and 3.72 × 10-5 mmol cm-2 s-1, respectively for K, being 72.0%, 61.4%, and 73.6% higher than the andesite rock. This highlights its potential use as a K source for agriculture to replace highly soluble K-fertilizers.

Effect of Temperature, Precursor Type and Dripping Time on the Crystallite Size of Nano ZnO Obtained by One-Pot Synthesis: 2k Full Factorial Design Analysis.

The aim of this work was to determine the effect of temperature, precursor and dripping time on the crystallite size of ZnO nanoparticles synthesized by controlled precipitation according a 2k full factorial design. ZnCl2, Zn(NO3)2 and NaOH were used as precursors. After synthesis, the nano crystalline powder was characterized by XRD (Cu Kα), UV-Vis, and HR-TEM. The nano ZnO particles presented a crystallite size between 210 and 260 Å (HR-TEM and XRD). The results show that the crystallite size depends on the type of precursor and temperature of synthesis, but not on the dripping time.

In vitro genotoxic effect of secondary minerals crystallized in rocks from coal mine drainage.

Coal processing generates a large volume of waste that can damage human health and the environment. Often these wastes produce acid drainage in which several minerals are crystallized (evaporites). This study aimed to identify secondary minerals, as well as the genotoxic potential of these materials. The samples were collected at two sites along the Rocinha River in Santa Catarina state (Brazil): (1) directly from the source of the acid drainage (evaporite 1), and (2) on the river bank (evaporite 2). The samples were characterized by X-ray diffraction and by particle-induced X-ray emission techniques. In vitro genotoxicity testing using Comet assay and Micronucleus test in V79 cells was used to evaluate evaporite samples. Our study also used System Biology tools to provide insight regarding the influence of this exposure on DNA damage in cells. The results showed that the samples induced DNA damage for both evaporites that can be explained by high concentrations of chromium, iron, nickel, copper and zinc in these materials. Thus, this study is very important due to the dearth of knowledge regarding the toxicity of evaporites in the environment. The genetic toxicity of this material can be induced by increased oxidative stress and DNA repair inhibition.

FTIR analysis and evaluation of carcinogenic and mutagenic risks of nitro-polycyclic aromatic hydrocarbons in PM1.0.

Nitro-polycyclic aromatic hydrocarbons (NPAHs) represent a group of organic compounds of significant interest due to their presence in airborne particulates of urban centers, wide distribution in the environment, and mutagenic and carcinogenic properties. These compounds, associated with atmospheric particles of size < 1 µm, have been reported as a major risk to human health. This study aims at identifying the spectral features of NPAHs (1-nitropyrene, 2-nitrofluorene, and 6-nitrochrysene) in emissivity and transmittance spectra of samples of particulate matter < 1 µm (PM1.0) using infrared spectrometry. Carcinogenic and mutagenic risks of the studied NPAHs associated with PM1.0 samples were also determined for two sampling sites: Canoas and Sapucaia do Sul. The results showed that NPAH standard spectra can effectively identify NPAHs in PM1.0 samples. The transmittance and emissivity sample spectra showed broader bands and lower relative intensity than the standard NPAH spectra. The carcinogenic risk and the total mutagenic risk were calculated using the toxic equivalent factors and mutagenic potency factors, respectively. Canoas showed the highest total carcinogenic risk, while Sapucaia do Sul had the highest mutagenic risk. The seasonal analysis suggested that in the study area the ambient air is more toxic during the cold periods. These findings might of significant importance for the decision and policy making authorities.

Liquid chromatography-atmospheric pressure photoionization-Orbitrap analysis of fullerene aggregates on surface soils and river sediments from Santa Catarina (Brazil).

In the present work, a new analytical approach is proposed for the analysis of seven fullerenes (C60, C70, N-methylfulleropyrrolidine, [6,6]-phenyl C61 butyric acid methyl ester, [6,6]-thienyl C61 butyric acid methyl ester, C60 pyrrolidine tris-acid ethyl ester and [6,6]-phenyl C71 butyric acid methyl ester fullerenes) in soils and sediments. This procedure combines an ultrasound-assisted solvent extraction (UAE) with toluene followed by liquid chromatography (LC), using a pyrenylpropyl group bonded silica based column, coupled to a high-resolution mass spectrometer (HRMS) using atmospheric pressure photoionisation (APPI) in negative ion mode. The analytical performance for fullerene separation of the pyrenylpropyl group bonded silica column was compared to the C18 column. For the ultra-trace analysis of fullerenes in complex environmental samples, the use of the APPI source and the use of the electrospray ionisation (ESI) source were compared. Using this approach for the analysis of fullerenes in complex matrices, a series of advantages, in terms of sensitivity and specificity, have been demonstrated. The method limits of detection (MLOD) and the method limits of quantification (MLOQ) in soils and sediments ranged from 0.022 to 0.39 pg/g and from 0.072 to 1.3 pg/g, respectively. Recoveries were between 68 and 106%. The analytical method was applied in order to assess the occurrence of selected fullerenes in 45 soils of Sul Catarinense (Santa Catalina State, Brazil) and 15 sediments from the Tubarão River, presenting different pressures of contamination: a coal-combustion power plant, car exhaust, coal mining industry and wastewater effluents. C60 and C70 fullerenes have been detected at concentrations ranging from the MLOD to 0.150 ng/g. None of the functionalised fullerenes were detected in any of the samples. Combustion processes, in particular car exhaust, were identified as the main source of fullerenes. However, the potential degradation of residual concentrations of engineered fullerenes to more stable forms, such as C60 and C70, should also be considered.