Toxicological studies use “specialty chemicals” and, thus, should assess and report both identity and degree of purity (homogeneity) of the chemicals (or toxicants) under investigation to ensure that other scientists can replicate experimental results. Although detailed reporting criteria for the synthesis and characterization of organic compounds have been established by organic chemistry journals, such criteria are inconsistently applied to the chemicals used in toxicological studies. Biologically active trace impurities may lead to incorrect conclusions about the chemical entity responsible for a biological response, which in turn may confound risk assessment. Based on our experience with the synthesis of PCBs and their metabolites, we herein propose guidelines for the “authentication” of synthetic PCBs and, by extension, other organic toxicants, and provide a checklist for documenting the authentication of toxicants reported in the peer-reviewed literature. The objective is to expand guidelines proposed for different types of biomedical and preclinical studies to include a thorough authentication of specialty chemicals, such as PCBs and their derivatives, with the goal of ensuring transparent and open reporting of scientific results in toxicology and the environmental health sciences.

Due to the increasingly severe situation regarding adaptation to climate change, global attention has focused on whether China can fulfill its commitment to the Paris Agreement as the largest producer of carbon dioxide (CO₂) emissions. In this study, the CO₂ emissions and CO₂ intensities in China during 2030 were forecast using three scenarios, seven indicators, and a back-propagation neural network. Under the business as usual (BAU), strategic planning (SP), and low carbon (LC) scenarios, the predicted CO₂ emissions in China during 2030 are 13,908.00, 11,837.60, and 9102.50 million tonnes, respectively, and the predicted CO₂ intensities are 1.8652, 1.7405, and 1.5382 when considering carbon capture, utilization, and storage (CCUS). Furthermore, China cannot fulfill its commitment under the BAU scenario, whereas China will fulfill its commitment on schedule under the SP scenario. Under the LC scenario, China will fulfill its commitment ahead of schedule to reduce the CO₂ intensity by 60% in 2025, and it will even reduce the CO₂ intensity by 65% in 2030. In addition, if the amounts of CCUS are not considered for measuring the CO₂ intensity, China can still fulfill its commitment under the LC scenario, whereas it cannot fulfill its commitment by 2030 under the SP scenario. This study evaluated the fulfillment of China’s commitment in the Paris Agreement, demonstrated that CCUS plays an important role in reducing the CO₂ intensity, and provided policy suggestions for the Chinese government regarding the reductions of the CO₂ intensity.

The increase in medicine and drug consumption have resulted in identifying these emerging pollutants in all aquatic compartments, ranging from surface water and groundwater resources to the marine environment. Pharmaceuticals are an indispensable part of life today. A large number of pharmaceuticals are used in a daily basis in the treatment, prevention, cure or diagnosis of diseases or to otherwise enhance people’s physical or mental well-being. This paper focuses on the evaluation of the attitude of citizens in Cyprus regarding the disposal of pharmaceuticals as well as to identify the main reasons why pharmaceutical wastes are produced. The result indicted that in Cyprus, there is lack of data regarding the amount of pharmaceutical wastes that are discarded into household waste and sinks. The survey audit showed that 86.6% of men’s and 83.3% of women’s used pharmacy with or without doctor’s recipe. Social behaviour is considered to be the most significant reason that pharmaceutical are produced. The results indicated that, citizens mainly keep unused medicines and drugs at home in case they are needed again as well as patients use to cut-off or to reduce their treatment in case that on the first 3–6 days they feel better. The survey indicated that the main disposal method of unused or expired medicines and drugs is in household waste followed from the sink and the toilet. Furthermore, the main disposal solution of unused or expired medicines and drugs remain the household bin as well as the sewage system (sink or toilet), while a percentage more than 55% of the participants indicated that they will follow a specific waste management program if existing in place. Moreover, in order to reduce the production of pharmaceutical wastes, specific prevention activities must be considered.

Fe-based metal-organic framework MIL-88A microrods were synthesized by hydrothermal method, which were used to adsorb As(V) in water for the first time. The experimental results indicated that MIL-88A has a very fast adsorption rate towards arsenic in water. The kinetic and isothermal data for arsenic removal were better fitted to the pseudo-second-order kinetic model and Langmuir model, respectively, implying a chemical and monolayer adsorption for As(V) on MIL-88A microrods. Two rate-controlling processes during adsorption were revealed by the intraparticle diffusion model. The maximum adsorption capacity of MIL-88A reached 145 mg g⁻¹, higher than those of Fe-based MIL adsorbents reported previously, which probably originates from its unique microstructure with abundant OH⁻ groups and an unusual large swelling towards water. These show that Fe-based MIL-88A is a good candidate for arsenic removal.

Acetylcholinesterase (AChE) acts on the hydrolysis of acetylcholine, rapidly removing this neurotransmitter at cholinergic synapses and neuromuscular junctions as well as in neuronal growth and differentiation, modulation of cell adhesion (“electrotactins”) and aryl-acylamidase activity (AAA). This enzyme is also found in erythrocyte, as 160 kDa dimer that anchors to the plasma membrane via glycophosphatidylinositol. The function of this enzyme in erythrocytes has not yet been elucidated; however, it is suspected to participate in cell-to-cell interactions. Here, a review on erythrocyte AChE characteristics and use as biomarker for organophosphorus and carbamate insecticides is presented since it is the first specific target/barrier of the action of these pesticides, besides plasma butyrylcholinesterase (BChE). However, some past and current methods have disadvantages: (a) not discriminating the activities of AChE and BChE; (b) low accuracy due to interference of hemoglobin in whole blood samples. On the other hand, extraction methods of hemoglobin-free erythrocyte AChE allows: (a) the freezing and transporting of samples; (b) samples free of colorimetric interference; (c) data from only erythrocyte AChE activity; (d) erythrocyte AChE specific activity presents higher correlation with the central nervous system AChE than other peripheral ChEs; (e) slow spontaneous regeneration against anti-ChEs agents of AChE in comparison to BChE, thus increasing the chances of detecting such compounds following longer interval after exposure. As monitoring perspectives, hemoglobin-free methodologies may be promising alternatives to assess the degree of exposure since they are not influenced by this interfering agent.

Carbon to nitrogen (C/N) ratio influences substrate combinations and earthworm performance in vermicomposting systems. To elucidate these factor effects, a comparative evaluation of species, C/N ratio combined with feed rate, was conducted on three local earthworm species: Perionyx excavatus, Eudrilus eugeniae, and Dichogaster annae. Earthworms were stocked at similar densities and fed shredded paper (SP), cattle manure (CM), and lawn clippings (LC) combined to form C/N ratios of 28, 36, and 53. Earthworms were fed at rates of 1, 1.25, and 2 g feed (dry wt.)/g worm/day for a period of 8 weeks. Percent vermiconversion, earthworm adult and juvenile biomass, and vermicast quality were measured. Vermicast production was significantly affected by the combination of C/N ratio and feed rate and varied among species. All treatment combinations resulted in > 70% conversion, except E. eugenaie fed at the medium rate. Vermiconversion increased for P. excavatus and D. annae with increasing C/N ratio but decreased with increasing the feed rate. Vermicast EC, pH, and C/N ratio was strongly affected by species, relative to other experimental factors. D. annae showed the greatest change in biomass, which peaked at the highest feed rate and lowest C/N ratio. Average adult biomass decreased for P. excavatus with increasing feed rate, while differences were nonsignificant for E. eugenaie and D. annae. Significant increases in average juvenile biomass were only evident for D. annae in response to increasing feed rates. Feed rate had a greater influence on earthworm population dynamics and vermicast quality compared to initial feedstock C/N ratio.

The concentrations of dissolved and particulate inorganic mercury (IHg(II)) and methylmercury (MeHg) from the contaminated Laranjo Bay (main freshwater discharge from the Antuã River) were measured by species-specific isotope dilution during six sampling campaigns at high and at low tide. Different effective riverine concentrations were calculated, based on salinity profiles, for specific hydrological conditions. The export fluxes of total Hg and MeHg (324 and 1.24 mol year⁻¹, respectively) from the bay to the rest of the Aveiro Lagoon are much higher than the input fluxes from the Hg source (3.9 and 0.05 mol year⁻¹) and from the Antuã River (10.4 and 0.10 mol year⁻¹). Resuspension of contaminated sediments from Laranjo Bay is crucial for the transport of both IHg(II) and MeHg. Methylation and/or selective enrichment into biogenic particles is responsible for the mobilization of MeHg. Sorption of dissolved IHg(II) onto suspended particles limits its export flux. This is one of the rarest examples where both speciation fluxes and partitioning of mercury are studied in a contaminated coastal environment. Despite the lower fraction of total MeHg (relative to total Hg), the contaminated lagoon may have an impact on coastal areas, particularly if change in the lagoon geometry occurs, due to sea level rise.

Metals from agricultural areas are responsible for soil contamination and are carried into aquatic ecosystems. In this context, we evaluated the incorporation of zinc and copper via three feeding strategies (shredding, herbivory and predators) in assemblages of stream insects. We collected aquatic insects in five agricultural streams and five natural streams in Atlantic forest biome to investigate the accumulation of copper and zinc in insects with different feeding strategies. We found no significant differences in the concentrations of copper and zinc between stream types among all insect-feeding groups compared. However, we observed that copper accumulate concentrations differed significantly among the shredders and predators in relation to their resource in streams, while zinc concentrations differed in the two feeding strategy. Therefore, the investigation of the transfer of copper and zinc by different feeding strategies in streams can contribute to the understanding of changes in aquatic insect assemblages related to agricultural activities around streams.

The organic matter existing in nature presents as a complex system of various substances. The humic fraction refers to the humic substances (HS) and consists of humic acids (HA), fulvic acids (FA), and humins, according to solubility in aqueous solution. The physical and chemical characteristics of HA, FA, and humins depend on many factors, among which is the type of original organic material. Two processes for the stabilization of organic materials are known worldwide: composting and vermicomposting. Cattle manure, rice straw, sugarcane bagasse, and vegetable wastes from leaves were the organic residues chosen for the composting and vermicomposting processes. In this study, the differences between the HS extracted from such composted and vermicomposted residues were evaluated. The so-extracted HS were evaluated by spectroscopy in the regions of infrared and ultraviolet-visible, and pyrolysis coupled with gas chromatography with mass spectrometric detection is applied. Thus, we expect that the results obtained here indicate which of the two processes is more efficient in the biotransformation of organic residues in a short period with respect to the HS content. It was also observed that the basic units of the humic fractions generated (although they presented different degrees of maturation) are the same. Altogether, the data reported here bring to light that the structures of the HS are very similar, differing in quantities. These results can still be extrapolated to several other raw materials, since the most variable organic matrices were used here to allow this data extrapolation. In addition, the process seems to lead to the formation of more aliphatic substances, counterpoising what is found in the literature.

Despite governmental efforts toward the development of policies, funds, and technologies, the inherent characteristics of rural solid waste (RSW) discharge have led to great difficulties in RSW pollution control. However, establishing a realistic management strategy requires greater knowledge of RSW generation. Therefore, the RSW of 72 typical towns and villages from 12 provinces of China was analyzed for physicochemical characteristics, as well as its spatiotemporal distribution. The largest proportion of kitchen waste, coal ash, plastic, and paper of RSW was 33.70% ± 17.87%, 26.50% ± 17.61%, 13.48% ± 5.68%, and 10.75% ± 5.75%, respectively, in 2015. Although RSW had the potential for composting, it was still necessary to pay special attention to heavy metals pollution of RSW. The spatiotemporal distributions of RSW components were extremely non-homogenous, and significant variations existed in the kitchen residue, coal ash, plastic, and paper because of differences in economic growth, climatic changes, dietary habits, energy consumption structure, and consumer preferences. No obvious differences in RSW components were observed between villages and market towns. Overall, RSW treatment and management approaches should be considered based on local conditions of RSW generation.