Distribution, sources, and risk analysis of heavy metals in sediments of Xiaoqing River basin, Shandong province, China.

The accumulation of heavy metals in river sediment poses a major threat to ecological safety. The Xiaoqing River originates in western Jinan, with higher population density and per capita gross domestic product (GDP) in its basin compared to the Shandong province average. This study analyzed the spatial characteristics, ecological risk, human health risk, and contamination sources of heavy metals by collecting sediment samples from Xiaoqing River. We use the methods such as geo-accumulation index (Igeo), ecological risk assessment based on the interval number sorting method, and health risk assessment to evaluate the risk of heavy metals in sediments. The research finding suggests heavy metals including Pb, As, Ni, and Cr are low ecological risks, while Hg and Cd have reached high and extreme ecological risks. Correlation analysis and principal component analysis were used to analyze the correlation and sources of different heavy metals. The six heavy metals were categorized into three groups. Factor 1, comprising Hg, Cr, and Pb, was identified as a mixed source with a contribution rate of 37.76%. Factor 2 is an agricultural source and comprises Ni, Cd, and As with a contribution rate of 27.05%. Factor 3 includes Pb and Ni contributing to 15.30% as a natural source. This study offers valuable insights for the prevention of heavy metal pollution, as well as promoting sustainable urban development.

Stakeholders' views towards plastic restriction policy in China: Based on text mining of media text.

With the massive use of plastic products, plastic pollution has increasingly attracted worldwide attention. To deal with the problem of plastic pollution, the Chinese government issued the "Opinions on Further Strengthening the Control of Plastic Pollution" (Abbreviated as OFSCPP), which is known as "plastic restriction policy" by the public, in January 2020. It stipulates the timetable and main tasks for restricting the production, sales, and use of certain plastic products, such as plastic bags, disposable straws and agricultural mulch. Since the policy was officially implemented on January 1, 2021, people's lives in China have been considerably affected, and it has also attracted widespread attention from news media. In this study, 310 pieces of news items and information about the OFSCPP published in the first quarter of 2021 from the Baidu News website from which 44, 94, 90, 26, and 49 statements from producers, retailers, consumers, managers, and experts were extracted. The extracted words and expressions were then analyzed using the Latent Dirichlet Allocation topic model. Text analysis results showed that the production efficiency of plastic substitutes in China cannot meet market demand, consumers' experience on plastic substitutes is poor, and recycling and disposal processing information is opaque. To achieve the policy goals, the government should encourage the innovation of high-quality and inexpensive plastic alternatives, the national standards for plastic substitutes should be urgently improved, consumers' concept of green consumption should be gradually cultivated, and terminal recycling and disposal should be promoted.

Environmental management strategy in response to COVID-19 in China: Based on text mining of government open information.

Coronavirus disease 2019 (COVID-19) is a global pandemic and a major health emergency. In the process of fighting against COVID-19, the China Ministry of Ecology and Environment (MEE) responded quickly and set up a working group as soon as possible. This article uses text mining to retrospectively analyze the government's public information on the website of MEE during the epidemic, sort out the timeline of MEE's response to COVID-19. We find that MEE's work during the COVID-19 pandemic is focused on medical waste and wastewater treatment, environment emergency monitoring, pollution prevention, and other environmental management for supporting economic recovery. It drafted three main medical waste management plans, an emergency environmental monitoring plan, and formulated "two lists" - a Positive checklist for Environmental impact assessment (EIA) approval and a positive checklist for supervision and enforcement, to promote the resumption of work and production. 2020 is the final year of China's "three years of fighting pollution prevention and control". In the case of the sudden COVID-19 epidemic, the Chinese environment department has ensured that the quality of the ecological environment has not been affected by the epidemic prevention and control while ensuring the smooth progress of the fight against pollution. China's medical waste disposal capacity has also been greatly improved during this epidemic. The review of China's environmental management strategy in response to COVID-19 can provide a reference for countries in the world that are still in the critical period of epidemic control; it can provide action guidelines for the ecological environment system to respond to sudden pandemic events in the future.

A carbonothioate-based far-red fluorescent probe for the specific detection of mercury ions in living cells and zebrafish.

The detection of ionic mercury (Hg2+) is very important because it is a highly toxic environmental pollutant that could cause serious diseases and threaten human health. Herein, we designed a new carbonothioate-based far-red fluorescent probe, CBRB, with a seminaphthorhodafluor dye as the fluorophore for the detection of Hg2+. The CBRB probe by itself exhibited very weak fluorescence due to the enhanced photo-induced electron transfer (PET) effect and inhibited the intramolecular charge transfer (ICT) process caused by the carbonothioate moiety. Upon addition of Hg2+, a tremendous fluorescence enhancement was achieved, attributed to the removal of the carbonothioate group via a specific mercury-promoted desulfurization reaction. Moreover, the probe displayed a large Stokes shift (about 105 nm) and was used to quantitatively measure the concentration of Hg2+ for concentrations ranging from 0 to 1 µM (DL = 3.6 nM). In addition, CBRB in our experiments responded exclusively to Hg2+, even in the presence of high concentrations other ions. Gratifyingly, this probe was successfully used to monitor Hg2+ in environmental water samples and to image Hg2+ in living cells as well as in zebrafish.