Galbraithpower9637

Statistical protocols for the estimation of geochemical background were applied to an existing database of till geochemistry (N = 1490) after removing samples from mining impacted areas. Results suggested geochemical background for the region is 0.25-15 mg kg-1 As, comparable to global averages, with upper thresholds elevated in volcanic units (30 mg kg-1 As) that often host sulfide mineralization in greenstone belts in the region.Humic-like substances (HULIS) in PM2.5 emitted from biomass burning (BB), including maize cob, wheat straw, maize straw, wood branch, and wood, in a traditional "Heated Kang" were investigated. The relative abundances, optical properties, chemical functional groups, and molecular components in HULIS were characterized using total organic carbon (TOC) analyzer, ultraviolet-visible spectroscopy (UV-vis), Fourier-transform infrared spectroscopy (FT-IR), and Fourier-transform ion cyclotron resonance mass spectrometer (FT-ICR/MS), respectively. The emission factors (EF) of HULIS-C (in term of carbon weight, EFHULIS-C) from BB were in the range of 0.83 to 5.17 g/kg fuel, with a mean value of 1.93 ± 1.31 g/kg fuel. The HULIS-C accounted for 15.0-37.8% and 9.1-12.6% of fractions in organic carbon (OC) and PM2.5, respectively, suggesting that BB is an important emission source of atmospheric HULIS. The FT-IR spectra showed BB HULIS mainly contain O-containing, aliphatic CH, and aromatic CC functional groups. The presences of carboxyl group and OH band demonstrated the uniqueness of maize straw and wood burning. Moreover, the higher ratio of CH3 and -CH2 groups could be used to distinguish the wood branches from the maize cob. Selleckchem MS023 CHO and CHON were much dominant in BB HULIS, which accounted for 44.6-47.6% and 50.1-54.2%, respectively, to the total molecular mass. The positive correlation between MAE365 and AAE in term of number concentration of CHNO implied that the CHNO species could greatly influence on the light absorption properties of the BB HULIS. The CHO and S-containing compounds (i.e., CHNOS and CHOS, that is CHNOS+CHOS) showed weak light absorbances of the BB HULIS. The BB HULIS from maize straw had relatively high molecular weight in comparison to that in other BB emissions. The highest and lowest aromaticity were seen on the wood burning and maize cob, respectively.The inadequate management of soils and the absence of conservation practices favor the degradation of pastures and can trigger adverse environmental alterations and damage under the terms of Brazilian Federal Law no. 6.938/1981. Based on this premise, this study aimed to estimate soil losses caused by water erosion in pasture areas using the brightness index (BI) from the annual series of Landsat 8 images in different geological formations. A specifically prepared Google Earth Engine (GEE) script automatically extracted the BI from the images. The study occurred in the Environmental Protection Area (EPA) of Uberaba River basin (Minas Gerais, Brazil). To accomplish the goal, 180 digital 500-wide random buffers were selected from 3 geologic types (60 points per type), and then analyzed for zonal statistics of USLE (Universal Soil Loss Equation) soil loss and BI in a Geographic Information System. The regression models BI versus USLE soil loss allowed estimating BI soil losses over the pastures of EPA. The model fittings were remarkable. The validation of soil loss maps in the EPA occurred in pasture phytophysiognomies through the probing of penetration resistance in 37 randomly selected locations. The results were satisfactory, mostly those based on the BI. The BI losses increased for greater resistances. Amplified losses also occurred in regions exposed to environmental land use conflicts (actual uses that deviate from land capability or natural use). Overall, the BI approach proved efficient to accurately track soil losses and pasture degradation over large areas, with the advantage of standing on a single parameter easily accessed through remote sensed data. From an environmental standpoint, this is an important result, because the accurate diagnosis and prognosis of degraded pastures is paramount to implement mitigation measures following the "polluter pays principle", even more in Brazil where the areas occupied by degraded pastures are enormous.Microplastics (MPs) are a growing threat to marine biota and ecosystems, and zooplankton are at high risk of ingesting MPs. The seasonal changes in MPs in zooplankton and the key environmental factors influencing the retention of MPs in zooplankton are largely unknown. For the first time, the characteristics of MPs in copepods across four seasons in Jiaozhou Bay. The abundance, shape, size, and chemical composition of the MPs in copepods were investigated, and the relationships between the MP/copepod value and key environmental factors were analyzed. The results revealed a significant seasonal difference in MP/copepod values in Jiaozhou Bay. MP/copepod values were 0.26, 0.23, 0.14 and 0.16 in February, May, August and November, respectively. The MP/copepod value was significantly higher in winter and spring than in summer and significantly higher in the estuarine zone than in other zones. Seawater temperature was negatively correlated with the MP/copepod value. No significant seasonal differences were detected in the characteristics of MPs in copepods in Jiaozhou Bay. The size of MPs in copepods ranged from 90 to 2485 μm, with an average of 454 ± 376 μm. Fiber MPs were the most risky to copepods, accounting for 92% of the total ingested MPs. In terms of the chemical composition of the MPs, a total of 11 polymers were detected in copepods in Jiaozhou Bay in the four seasons. The main components were polyester and cellophane (41.9% and 25.7%, respectively). This study provides the key parameters of the MPs in copepods in Jiaozhou Bay and is an important basis for further ecological risk assessments of MPs. The chronic effects of low-level MP retention on copepods, the impact of fibers on copepods, and appropriate assessments of MP risk under different environmental conditions are recommended as research topics for the next step toward developing an environmentally relevant MP risk assessment. THE MAIN FINDING The seasonal characteristics of microplastics ingested by copepods in Jiaozhou Bay were revealed.