In the present scenario, the synthesis and characterization of zinc oxide (ZnO) and cerium oxide (CeO₂) nanoparticles (NPs) through biological routes using green reducing agents are quite interesting to explore various biomedical and pharmaceutical applications, particularly for the treatment of cancer. This study was focused on the phytosynthesis of ZnO and CeO₂ NPs using the leaf extract of Rubia cordifolia L. The active principles present in the plant extract were liable for rapid reduction of Zn and Ce ions to metallic nanocrystals. ZnO and CeO₂ NPs were characterized by UV–visible spectroscopy, X-ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), energy dispersive X-ray spectroscopy (EDAX), and photoluminescence (PL) techniques. ZnO and CeO₂ NPs were partially agglomerated with a net-like structure. Biomedical activities of ZnO and CeO₂ NPs were tested against MG-63 human osteosarcoma cells using MTT and reactive oxygen species (ROS) quantification assays. In treated cells, loss of cell membrane integrity, oxidative stress, and apoptosis was observed and it is well correlated with cellular damage immediately after induction. Overall, this study shed light on the anti-cancer potential of ZnO and CeO₂ NPs on MG-63 human osteosarcoma cells through differential ROS production pathways, describing the potential role of greener synthesis.

The atmospheric dust is an important route of human exposure to kinds of pollutants particularly toxic heavy metals. The current study was carried out to assess the ecological and health risk assessment of Co, Cr, and Mn in the atmospheric dust of city of Hamedan, Iran. In so doing, a total of 54 samples of atmospheric dust were collected from the three regions of the study area in 2014. After acid digestion of samples in the laboratory, the Co, Cr, and Mn contents were determined using inductively coupled plasma-optical emission spectrometer (ICP-OES). The results showed that the average contents (mg kg⁻¹) of Co, Cr, and Mn in the analyzed samples were 0.23, 0.89, and 8.10, respectively. The results of human health risk assessment showed that ingestion of dust particles is the main exposure route to heavy metals in the dust for the local residents. Also, the upper limit of the 95% confidence interval of hazard indices for non-carcinogenic risks of all analyzed metals in the atmospheric dust was within the safe level (= 1) for both children and adults. The carcinogenic risk levels of Co and Cr were all lower than the acceptable range for local citizens. Based on the results, it can be suggested that special attention be paid to toxic heavy metals that long-term exposure to which via atmospheric dust can have adverse effects on the city resident health.

In China, agriculture produces the greatest chemical oxygen demand (COD) emissions in wastewater and the most methane (CH₄) emissions. It is imperative that agricultural pollution in China be reduced. This study investigated the influencing factors of the CO₂ emission intensity of Chinese agriculture from 1997 to 2014. We analyzed the influencing factors of the CO₂ emission intensity through the first-stage least-square regression. We also analyzed determinants of innovation through the second-stage least-square regression. We found that innovation negatively affected the CO₂ emission intensity in the model of the nation. FDI positively affected innovation in China. It is important to enhance indigenous innovation for green agriculture through labor training and collaboration between agriculture and academia.

A study on ¹³⁷Cs pollution and activity concentrations of ⁴⁰K in mushrooms of the genera Cortinarius, Leccinum, Russula, Tricholoma, Tylopilus, and Xerocomus from two neighboring regions in southwest China in 2010–2013 revealed different patterns of pollution with ¹³⁷Cs, which seemed to be highly dependent on climate conditions. Tricholoma matsutake was collected in Yunnan before and after the Fukushima Dai-ichi nuclear accident and showed similar contamination with ¹³⁷Cs. Mushrooms from the elevation of 2800–3480 m above sea level on the east slope of Minya Konka and forest topsoil showed higher contamination with ¹³⁷Cs than mushrooms from the highlands of Yunnan. In detail, the activity concentration of ¹³⁷Cs in caps of mushrooms from Minya Konka were in the range 62 ± 6–280 ± 150 Bq kg⁻¹ dry biomass and from Yunnan at < 4.4–83 ± 3 Bq kg⁻¹ dry biomass. The climate in the region of the Minya Konka is much colder than in Yunnan, which seems to favor deposition of ¹³⁷Cs at higher altitudes from global atmospheric circulation. The activity concentration of ⁴⁰K in mushrooms and soils highly exceeded that of ¹³⁷Cs. The assessed annual effective doses for ¹³⁷Cs in 1 kg of consumed mushrooms of the genera Leccinum and Xerocomus in Yunnan were low, i.e., in the range < 0.0043–0.049 ± 0.004 μSv, while those for ⁴⁰K were 0.26 ± 0.02–0.81 ± 0.09 μSv.

Batch experiments have been carried out to study the adsorption of heavy metals in soils, and the migration and transformation of hexavalent chromium (Cr(VI)) in the soil of a vegetable base were studied by dynamic adsorption and desorption soil column experiments. The aim of this study was to investigate the effect of initial concentration and pH value on the adsorption process of Cr(VI). Breakthrough curve were used to evaluate the capacity of Cr(VI) adsorption in soil columns. The results show that the higher the initial concentration, the worse the adsorption capacity of Cr(VI). The adsorption of Cr(VI) was strongly sensitive to pH value. The capacity of Cr(VI) adsorption is maximized at very low pH value. This may be due to changes in pH that cause a series of complex reactions in Cr(VI). In a strongly acidic environment, the reaction of Cr(VI) with hydrogen ions is accompanied by the formation of Cr³⁺, which reacts with the soil free iron-aluminum oxide to produce hydroxide in the soil. The results of the desorption experiments indicate that Cr(VI) is more likely to leach from this soil, but if the eluent is a strong acid solution, the leaching process will be slow and persistent. During the experiment, the pH value of the effluent was in the range of 7–8.5, which tends to the original pH value of the soil. It is indicating that the soil has a strong buffer on the acid liquid. The program CXTFIT was used to fit the breakthrough curve to estimate parameters. The results of the calculation of the dispersion coefficient (D) can be obtained by this program. The two-site model fit the breakthrough curve data of Cr(VI) well, and the parameters calculated by the CXTFIT can be used to explain the behavior of Cr(VI) migration and transformation in soil columns. When pH = 2, the retardation factor (R) reach at 79.71 while the value of the R is generally around 10 in other experiments. The partitioning coefficient β shows that more than half of the adsorption sites are instantaneous in this adsorption process and non-equilibrium affects the Cr(VI) transport process in this soil.

The uptake of major and trace elements in grapevine (Vitis vinifera L.) can be influenced by soil, climate, geographic origin, and rootstock type. Rootstocks were mainly selected to resist phylloxera and for specific tolerance to lime, mineral uptake, drought, and salinity. The relationship among concentrations of major, trace, and rare earth elements was studied in soil and leaves from two Italian grapevine cultivars, “Cabernet Sauvignon” and “Corvina,” employed to produce renowned controlled designation of origin (DOC) wines. The cultivars were raised on the same rootstock SO4 in two different areas of the Veneto Region (Northern Italy). The elements were studied by X-ray fluorescence and inductively coupled plasma mass spectrometry, and data were elaborated by non-parametric tests and multivariate linear discrimination analysis. The related index of bioaccumulation was calculated to define the specific assimilation of the elements from soil to leaves. A statistically significant correspondence between soil and leaf samples was observed for Mg, Sm, V, and Zr. The results allowed to discriminate soil and leaf samples of the two cultivars according to geographical provenance, possibly providing geochemical markers (fingerprints) useful against fraudulent use of DOC wine labels.

The pollution of heavy metals is a severer problem for the ecosystems in waters. The toxicity of Cd²⁺ on phycocyanin (PC) is studied in molecular level in this work. The fluorescence quenching of PC is observed by the adding Cd²⁺ from 0 to 500 × 10⁻⁷ mol L⁻¹. From the theoretical calculation and the time-resolved fluorescence decay profiles, the fluorescence quenching of PC by Cd²⁺ is found to be static. The synchronous fluorescence spectra are used to study the change in amino acid residues of PC molecules, indicating that the effect of Cd²⁺ on the Trp of PC is more significant than the Tyr. The UV-Vis absorbance of tetrapyrrole decreases from 0.26 to 0.23 cps with increasing Cd²⁺ concentration, suggesting that Cd²⁺ affects the light adsorption and the photosynthesis function of PC. The circular dichroism spectra reveal that adding Cd²⁺ also changes the secondary structure (α-helix) of PC.

Starting with the 2007–2008 cycle, the National Health and Nutrition Examination Survey (NHANES) also oversampled Hispanics other than Mexicans (OHISP) making it possible to treat OHISP as a separate demographic group along with Mexican Americans (MAs), non-Hispanic whites (NHWs), and non-Hispanic blacks (NHBs). Yet, more often than not, OHISP have been merged with MA to form an all-Hispanic demographic group (HISP) thus limiting comparisons between NHW, NHB, and HISP. Consequently, for the first time, this study was undertaken to evaluate differences in the observed levels of selected environmental contaminants between MA and OHISP from five groups of environmental contaminants, namely, polycyclic aromatic hydrocarbons (PAHs), iodine uptake inhibitors (IUIs), environmental phenols (EPHs), priority pesticides (PPs), and perfluoroalkyl acids (PFAAs). Data for 2007–2010 from NHANES were used to conduct this study. OHISP children born in USA had higher levels of selected PAH metabolites than USA-born MA, and Mexican-born MA adolescents had higher levels of selected PAH metabolites than USA-born MA adolescents. USA-born adolescent MA had higher levels of selected parabens than USA-born adolescent OHISP, and OHISP adults born in another Spanish-speaking country had higher levels of selected parabens than USA-born OHISP adults. USA-born MA adults and seniors had higher levels of selected dichlorophenols than Mexico-born MA adults and seniors, respectively. Females had higher levels of selected PAH metabolites, EPHs, and PPs than males among children, adolescents, adults, and seniors, but the reverse was true for the levels of selected IUIs and PFAAs among adolescents and seniors. Smokers had higher levels of almost all PAH metabolites than non-smokers for adolescents, adults, and seniors. The same was true for urinary thiocynate for adolescents, adults, and seniors. OHISP is a multiracial multiethnic demographic group substantially different from MA with possibly different smoking behavior and with possibly differential levels of exposure to certain environmental contaminants and as such should be treated as a demographic group by itself.

A novel chitosan/ceria/iron oxide (CS/ceria/Fe₃O₄) nano-composite adsorbent was synthesized for removal of Cr(VI) and Co(II) ions from aqueous systems in a batch system. The adsorbents were characterized by field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), thermal gravimetric analysis (TGA), and Brunauer- Emmett-Teller (BET) analyses. The behavior of swelling kinetics was also studied. The effect of several adsorption parameters including CeO₂ and Fe₃O₄ contents, initial pH, contact time, initial Cr(VI) and Co(II) concentration, and temperature on the adsorption capacity was studied. The double exponential model revealed a better fit with the kinetic data of Cr(VI) and Co(II) ions. The Cr(VI) and Co(II) adsorption process well fitted the Langmuir model. The maximum adsorption capacities estimated from Langmuir isotherm model were 315.4 and 260.6 mg/g for Cr(VI) and Co(II) ions, respectively. Also, thermodynamic parameters were used to distinguish the nature of Cr(VI) and Co(II) adsorption. The reusability of CS/ceria/Fe₃O₄ nano-composite was evaluated with stripping agents of 0.1 M NaOH and 0.1 M HNO₃. Finally, the evaluation of Cr(VI)-Co(II) coexisting system confirmed that the presence of Co(II) ions played an inhibitor role on the Cr(VI) adsorption.

In this work, a new norm descriptor is proposed based on atomic properties. A quantitative structure-activity relationship (QSAR) model for predicting the toxicity of organic compounds to fathead minnow is further developed by norm descriptors. Results indicate that this new model based on the norm descriptors has satisfactory predictive results with the squared correlation coefficient (R²) and squared relation coefficient of the cross validation (Q²) of 0.8174 and 0.7923, respectively. Combining with Y-randomization test, applicability domain test, and comparison with other references, calculation results indicate that the QSAR model performs well both in the stability and the accuracy with wide application domain, which might be further used effectively for the safe and risk assessment of various organics.