Comprehensive observations have been carried out in Beijing to investigate the impact of the Clean Air Action implemented in 2013 on changes in aerosol chemistry characteristics in heating seasons of 2016-2017 and 2017-2018. Results showed that PM2.5, SO2, NO2, NH3, O3 and CO concentrations decreased by 40.9%, 46.0%, 29.0%, 40.6%, 11.0% and 44.4%, respectively. Significant decreases were also observed for NO3- (32.5%), SO42- (52.9%), NH4+ (56.0%), Cl- (64.6%) and K+ (68.2%), on average. Enhanced PM2.5 pollution has changed from sulfate-driven to nitrate-driven. The decrease in SO2 was more significant than NO2 as a response to one reason of the larger decrease in SO42- concentration. The formation of sulfate was dominated by heterogeneous reactions in two heating seasons. Low pH could facilitate more efficient conversion of SO2 to sulfate. Photochemical reactions played a much more important role in the formation of nitrate in the second heating season, especially in the daytime. The major source regions for sulfate and nitrate were identified by back trajectories and the potential source function (PSCF). More nitrate was brought into Beijing when air masses coming from polluted regions in the southwest prevailed in 2017-2018 heating season. Thus, regional joint prevention and control are of great importance in the achievement of an effective reduction in PM2.5 pollution in the future.Although banished in some countries, triclosan (TCS) and triclocarban (TCC) have been detected in surface waters in concentrations ranging from ng L-1 to μg L-1 and have shown to affect non-target organisms posing risk to aquatic ecosystems. However, the majority of the studies consider higher levels of these chemicals and single exposure effects to investigate their potential risks, rather than using environmentally relevant concentrations and their binary mixture. In this study, the toxicity of TCS and TCC, and their binary mixture was assessed in catfish embryos (Rhamdia quelen, a south American native species) exposed to environmental concentrations during 96 h. Organisms were evaluated through the endpoints of developmental abnormalities (spine, fin, facial/cranial and thorax), biochemical biomarkers related to oxidative stress responses catalase (CAT), superoxide dismutase (SOD), glutathione-S-transferase (GST) activities, protein carbonylation (PCO) and neurotoxicity by acetylcholinesterase activity (AChE). The data showed that TCS caused fin abnormalities, decrease of SOD activity and increase of AChE activity in the catfish embryos of 96hpf. On the other hand, TCC and the binary mixture showed a higher abnormality index for the 96hpf embryos, and an induction of CAT and GST activities for the mixture treatment. The results obtained were able to show potential, but not severe, toxicity of TCS and TCC even in low concentrations and a short period of exposure. The relevance of studies approaching real scenarios of exposure should be reinforced, considering environmental concentrations of chemicals, interactions of contaminants in complex mixtures and the use of a native species such as R. quelen exposed during initial stages of development.Rare earth elements (REEs) are essential in high technology industries and have great economic value. The monitoring of REEs concentrations in rocks from oil well drill cuttings is critical to avoid environmental contamination and evaluate new sources of these elements. However, information is scarce about the REEs concentrations in drill cuttings. In this work, the concentration of REEs in drill cuttings from oil and gas exploration wells in ultradeep coastal water of Brazilian were investigated at different depths. The drill cutting samples were submitted to microwave-assisted acid digestion prior to the determination of concentration by ICP-MS, using Rh as internal standard for calibration. The limits of quantification (LoQ) ranged from 3.3 μg kg-1 for Ho to 198 μg kg-1 for Sm. The accuracy was evaluated by analyzing certified reference materials for rocks. The obtained REEs concentrations agreed with the certified values, reaching 83%-105% agreement. The drill cutting depth profile analysis indicates Ce, La, Nd, Sm, and Eu concentrations up to mg kg-1.  https://www.selleckchem.com/products/atglistatin.html  The REEs concentrations obtained in drill cutting depth profile was analyzed by principal component analysis (PCA), and hierarchical cluster analysis (HCA) identified tendency and similarity between drill cutting samples. Three groups were formed according to the composition of the REEs. In addition, the concentration of these chemicals elements varied at different depths. The analysis of drill cuttings revealed REEs concentrations up to the mg per kg-range (ppm), potentially making this disposable material an alternative source for REEs extraction, and adding value to this material.Scarce information is available concerning the presence of carbohydrates in rainwater. The existence of carbohydrates in bulk deposition at the town of Estarreja (Portugal), at industrial (I) and background (BG) locals, in winter and spring seasons 2016, was assessed. Seventeen carbohydrates and related compounds were identified monosaccharides (ribose, arabinose, xylose, glucose, galactose, fructose), disaccharides (sucrose, trehalose, maltose, cellobiose), polyols (arabinitol, xylitol, myo-inositol, mannitol, glucitol, maltitol), and the anhydromonosaccharide levoglucosan. Higher content of carbohydrates was observed in spring (BG 670 nM; I 249 nM) than in winter (BG 168 nM; I 195 nM), and fructose was the carbohydrate with the highest contribution in both seasons (spring 32%/44% (I/BG); winter 24% (at both sites)). Fructose, myo-inositol, glucose and sucrose showed higher volume-weighted averages (VWA) concentrations in spring than in winter, possibly due to biogenic emissions typical of spring, such as pollen, and fungal spores for myo-inositol. Fructose may have derived from isomerization of glucose in biomass burning, namely in winter. Levoglucosan and galactose presented higher VWA concentration in winter than in spring, suggesting a seasonal effect related with the biomass combustion. The carbohydrates VWA concentrations were similar for samples associated with maritime and terrestrial air masses, indicating that local sources were their main contributors. Source assessment of carbohydrates by factor analysis suggested biogenic sources for the arabinitol, myo-inositol, glucose, fructose and sucrose; soil dust for the trehalose; and anthropogenic sources from biomass burning for the galactose, arabinose and levoglucosan. The bulk deposition showed to be fundamental on removing carbohydrates from the atmosphere.