ACS Chemical Health & Safety最新文献

One of the environmental health and safety concerns is the toxicological impact of ultrafine particles (UFPs) and secondary inorganic ions on human health, particularly on the development of neurodegenerative diseases. According to recent research studies, UFPs can be absorbed to human blood and have a toxicological effect on human organs. Due to their small particle size, UFPs can translocate to the human brain and contribute to the progression of neurodegenerative diseases. In this work, a molecular dynamics study was performed to investigate the impact of carbon-based UFP, mimicked by fullerene C₆₀ molecule, on the aggregation of amyloid β (Aβ) peptides, which is related to the progression of Alzheimer’s disease. Moreover, the synergistic effect of the UFP and environmental pollutants was analyzed at various concentrations of the ions found in the environmental realm. In particular, the effect of C₆₀ on the aggregation kinetics of eight Aβ_16–21 peptides, the segment of Aβ peptide, was studied in the presence of NH₄NO₃ by varying the salt concentrations from 50 to 150 mM. Overall, the results showed the formation of large amounts of β-sheets in the systems with a slow initial rate of the aggregation of Aβ_16–21 peptide octamer. In the absence of the UFP, the slowest initial rate of the aggregation of Aβ_16–21 peptide octamer was observed at 50 mM salt concentration, while, in the presence of C₆₀, the slowest aggregation kinetics of Aβ_16–21 peptides was observed at 150 mM salt concentration. Moreover, in general, the presence of carbon-based UFP reduced the interpeptide interactions and decreased the initial rate of the aggregation of peptides due to the binding of peptides to C₆₀.

It is a challenging problem to monitor atmospheric CO₂ leakage due to the complex variation of the atmosphere background. In this research, a new CO₂ leakage identification method in the atmosphere based on the complex time–frequency spectrum of atmospheric CO₂ variation was proposed. First, the complex continuous wavelet transform (CWT) was utilized to analyze the experimental data without and with CO₂ leakage. It was found that CWT could provide distinguished features for atmospheric CO₂ leakage by calculating the time–frequency spectrum and modulus of CWT for the cases with a leakage rate from 5 to 25 m³/h. Further, the atmospheric CO₂ concentration and CO₂ variation rate were compared to recognize abnormal leakage. The results indicated that the CWT spectrum of the CO₂ variation rate performed better than that of concentration. Moreover, the CWT spectrum of the atmospheric CO₂ variation rate with the real-valued wavelet function was also utilized to recognize CO₂ leakage. The tests showed that the CWT spectrum with the complex Morlet wavelet demonstrated a more obvious and wider hot spot than that with the real-valued Morlet wavelet. In addition, a pretreatment method with principal component analysis (PCA) was applied to extract the features of original monitoring signals. It was proved that more obvious abnormal signals in the time–frequency spectrum and modulus variation PCA–CWT method could be captured than that from the original CWT analysis, even for a small leakage. Therefore, it is a feasible method to monitor and recognize atmospheric CO₂ leakage with the complex CWT of the CO₂ variation rate in the atmosphere combined with PCA processing.

In collaboration with C&EN

Counterfeit pesticides used in agriculture or public health services have become a worldwide problem. Adulteration of pesticides can occur in several stages of manufacturing the active ingredient (AI) when using poor raw materials and low-quality solvents to produce either the AI or the formulation by avoiding required purification procedures, leading to impurities in the form of stereoisomers (cis or trans). Also, counterfeit pesticide producers can use low-cost materials in manufacturing packaging materials, among other methods of adulteration. Impurities in counterfeit pesticides, such as ethylmethanesulfonate, isomalathion, or nonylphenol ethoxylates, could threaten human health, environmental components, and national economies. Elaborate tests are necessary to distinguish between original and counterfeit pesticides. Organized crime trades in counterfeit pesticides, driven by their great profits. Global revenues from counterfeit pesticide trade are estimated at more than €4.4 billion (US$5.4 billion) annually. On global and national levels, measures and rules must be followed to combat counterfeit and contraband pesticides. This Review describes the process of producing counterfeit pesticides, their health and economic effects, and Egypt’s prototypical measures in reducing and stopping this trend.

A violent explosion accident occurred when diaminomethanesulfonic acid was synthesized from diaminomethanesulfinic acid and hydrogen peroxide. In this work, we reviewed all the reported methods of synthesizing diaminomethanesulfonic acid and analyzed the causes of the explosion in detail from the reaction mechanisms and operations. In the end, strategies were proposed to avoid underlying explosion incidents in relevant experiments.

We developed, validated, and tested a tool in Mexico to assess the management of student and teacher health and safety, environmental protection, and community safety in high school science laboratories. Schools require such an instrument in order to capture and proactively identify opportunities for safety improvement. We developed a checklist by reviewing and adapting different sources. It can be used to evaluate a school’s management approach using a composite indicator, the Health, Safety, Civil, and Environmental Protection Management Indicator: IHSCE. The IHSCE comprises four sub-indicators: (1) health, safety, civil, and environmental policies; (2) management of chemicals; (3) facilities, safety, and emergency equipment; and (4) teacher training. The IHSCE tool was validated and tested in 41 high schools in the state of Sonora (Mexico). The IHSCE sub-indicator rankings ranged from medium to low in the science laboratories of schools in the capital of the state and in regional high schools. However, regional high schools had significantly lower levels in two IHSCE sub-indicators: the facilities, safety, and emergency equipment sub-indicator and the teacher training sub-indicator. The tool consists of a checklist that is flexible and comprehensive. Its use revealed differences in high school science laboratories and identified opportunities for the reduction of health and safety hazards in school facilities and communities and in the surrounding environment.

In collaboration with C&EN

Laboratory safety has been gaining increasing attention in Chinese universities in recent years. Robust laboratory designs will ensure the safety of personnel, instruments, and the environment. This Case Study shares the experiences and lessons learnt from the design and reconstruction of an organic analysis laboratory in Shenzhen University. The following aspects are discussed: (1) the layout of the laboratory; (2) ventilation, electricity, gas, and humidity control; (3) fire-fighting and emergency facilities; (4) chemical storage; and (5) waste management.