Insight of chemical environmental risk and its management from the vinyl chloride accident

The combustion of vinyl chloride(VC)after the train derailment accident in Ohio,USA in February,2023 has caused widespread concern around the world.This paper tried to analyze several issues concerning the accident,including the appropriateness of the VC combustion in the emergency response in this accident,the meanings of so-called“controlled combustion”,the potential environmental risks caused by VC and combustion by-products,and follow-up work.In our view,this accident had surely caused environmental and health risks to some extent.Hence,a comprehensive environmental risk assessment is necessary,and then the site with risk should be comprehensively remediated,hazardous waste should be harmlessly treated as soon as possible.Finally,this accident suggests that further efforts should be taken to bridge the gap between chemical safety management and their environmental risk management.

Endosulfan residues and farmers’replacement behaviors of endosulfan in the north-west inland cotton region

We assessed the situation of endosulfan residues in cotton fields after the endosulfan ban came into effect and the current knowledge,attitude,and practice(KAP)of cotton farmers on the phase-out of endosulfan and the application of alternative technologies.Topsoil samples(n=91)of cotton fields were collected from the major cotton-producing areas in China,namely the north-west inland cotton region,and the endosulfan residues were analyzed.A KAP survey was carried out for cotton farmers,and 291 questionnaires were distributed.The influences of gender,age,education background,cotton planting years,publicity and training,income sources,and other factors on cotton farmers’KAP were analyzed.The results showed that endosulfan sulfate was the main endosulfan residue in the soil,followed byβ-endosulfan andα-endosulfan,the average residual contents were 0.569,0.139,and 0.060μg/kg,respectively.The results of the KAP study showed that cotton farmers scored low on knowledge about the phase-out of endosulfan and the application of alternative technologies but high on attitude and practice.The number of family members,years of cotton planting,age,and the cottonplanting area had different degrees of influence on KAP scores.The training could significantly improve the KAP scores of cotton farmers;training should be more targeted and designed reasonably for key groups,such as men and the population under 30,followed by training them to use pesticides safely.For large-scale cotton growers,training should focus on green prevention and control technologies.

The occurrence of per-and polyfluoroalkyl substances(PFASs) in fluoropolymer raw materials and products made in China

Perfluorooctanoic acid(PFOA), its salts, and related compounds were listed as new persistent organic pollutants by the Stockholm Convention in 2019.In this study, the occurrence of residues of PFOA and other per-and polyfluoroalkyl substances(PFASs) in raw materials and fluoropolymer products from the Chinese fluoropolymer industries are reported for the first time.The PFOA concentrations in raw materials and fluoropolymer products were in the range of 6.7 to 1.1 × 10^(6) ng/g, and <MDL(method detection limit) to 5.3 × 10^(3) ng/g,respectively.Generally, the levels of PFOA in raw materials were higher than in products,implying that PFOA in the emulsion/dispersion resin could be partly removed during the polymerization or post-processing steps.By tracking a company’s polytetrafluoroethylene(PTFE) production line, it was found that over a 5 year period, the residual levels of PFOA in emulsion samples declined from 1.1 × 10^(6) to 28.4 ng/g, indicating that the contamination of PFOA in fluoropolymer products from production source gradually decreased after its use had been discontinued.High concentrations of HFPO-TrA(2.7 × 10^(5) to 8.2 × 10^(5) ng/g) were detected in some emulsion samples indicating this alternative has been widely applied in fluoropolymer manufacturing in China.

Twenty years of achievements in China’s implementation of the Stockholm Convention

Persistent organic pollutants(POPs)are extremely harmful to the environment and human health;the Stockholm Convention on Persistent Organic Pollutants was therefore adopted by the international community in 2001 to eliminate or reduce the production,use,and emissions of POPs.China is the largest developing country that has signed the Stockholm Convention,and thus plays an important role in its implementation.This paper systematically studies the practice and achievements of China since it signed the Stockholm Convention 20 years ago.China has established an implementation guarantee system including institutions,implementation mechanisms,policies,law enforcement,and scientific and technological support.During the 20 years since the implementation of the Stockholm Convention,dichlorodiphenyltrichloroethane(DDT)and hexachlorocyclohexane(HCH)concentrations in the air have been steadily decreasing,and Perfluorooctane sulfonic acid/Perfluorooctane sulfonyl fluoride(PFOS/PFOSF)concentrations in water bodies have decreased.In the past 20 years,China has safely disposed of 6352.1 tons of pesticide persistent organic pollutants and 36998 sets of electrical equipment containing polychlorinated biphenyls(PCBs),with a disposal rate of 100%.In the future,China will further strengthen the construction of persistent organic pollutant monitoring networks,scientific research,publicity,education,and international cooperation to improve environmental quality,providing a reference for other countries to implement the Stockholm Convention.

A comprehensive evaluation method for plateau freshwater lakes:a case in the Erhai Lake

The study first systematically assessed the ecosystem health status of the plateau freshwater lake of Erhai Lake in Yunnan Province of China,using the revised Freshwater Health Indicator methodology,which comprised three components,i.e.,“Ecosystem Vitality,”“Ecosystem Services,”and“Governance and Stakeholders.”To better reflect the real health status of the basin,the cask short board effect was considered during aggregation of the indicators.In addition,analysis of the coupling coordination relationship among the three components was conducted to study the mutual influences among them as well as the comprehensive development level of the studied area.Basically,the ecosystem of the Erhai Lake basin remained healthy during the studied period according to the research due to specific measures and actions taken to manage the environmental problems caused by a former local economic development and urbanization process.However,there were still aspects to improve for more sustainable ecosystem management and utilization in the basin.The“short boards”of the Erhai Lake basin show room for improvement in local freshwater ecosystem management and underline governance problems that need to be addressed.Suggestions are provided for the local stakeholders consequently for the more sustainable development of the studied basin.

Presence of organophosphate flame retardants(OPEs)in different functional areas in residential homes in Beijing,China

The production and application of organophosphate esters(OPEs)have dramatically increased in recent years due to their use as a replacement for brominated flame retardants.In this study,13 OPEs(∑_(13)OPEs)were analyzed in indoor air samples from kitchens and living rooms in 14 residential homes in Beijing,China.The concentrations of ∑_(13)OPEs in kitchen air samples(mean:13 ng/m^(3))were significantly(p<0.05)higher than in living room air samples(5.0 ng/m^(3)).In addition,paired window surface organic film samples were collected and analyzed to investigate film-air partitioning,exhibiting a mean concentration of ∑_(13)OPEs of 4100 ng/m^(2).The congener profiles showed that tris(2-chloroisopropyl)phosphate(TCPP)was the predominant compound in both window film samples(48%)and the corresponding indoor air sample(56%).The estimated daily intakes(EDI)of OPEs via indoor air inhalation were 2.8 and 1.4 ng/kg/day for infants and adults,respectively,both of which are below the reference dose values(RfDs).Overall,these findings indicate that OPEs in the indoor air environment of residential homes in Beijing are not likely to pose a health risk to the general population.

淡水和海水洪水对东南亚红树林生态系统稳定性影响的空间特征差异

In tropical regions,mangrove forests are located in the inter-tidal areas between land and sea,and are at risk from both freshwater and seawater floods.Using satellite-derived Normalized Difference Vegetation Index(NDVI)products,this study compared the differences in resistance and resilience of mangrove ecosystems to freshwater and seawater floods in Southeast Asia,and analyzed the spatial characteristics of the stability of mangrove ecosystems under floods in representative areas.Results show that mangroves tended to have lower mean resistance(28.24 vs.37.32)and higher mean resilience(3.74 vs.3.56)under freshwater floods,compared to seawater floods.Their resistance increased with the distance from rivers,such that the resistance of coastal areas to freshwater and seawater floods was lower than that of inland areas.These areas with lower resistance showed higher resilience compared to those with higher resistance.Damaged mangroves hardly fully recovered to their normal NDVI levels one year after seawater floods,especially in coastal areas.Although the occurrence of seawater floods was relatively rare in the past,it is likely to increase under more-intense climate extremes in the future,and the threat to the survival of mangroves may also increase.Thus,it is essential to evaluate the stability of mangrove ecosystems under floods.

State of art control of dioxins/unintentional POPs in the secondary copper industry: A review to assist policy making with the implementation of the Stockholm Convention

Article 5 of the Stockholm Convention requires that each Party shall take measures to reduce the releases from anthropogenic sources of unintentional persistent organic pollutants(UPOPs),with the goal of their continuing minimization and,where feasible,their ultimate elimination.A major source of polychlorinated dibenzo-p-dioxins and dibenzofurans(PCDD/Fs)and other unintentional POPs releases,both in China and worldwide,is the metal industry in particular secondary metal industries such as copper smelting.More than 50%of the global secondary copper production is now in China and high levels of PCDD/Fs are released from these operations with the national inventory of China reporting a total of 1133.8 g toxic equivalents(TEQ)yr1.Consequently the Global Environment Facility(GEF)is supporting the project‘UPOPs Reduction through best available techniques and best environmental practices(BAT/BEP)in the secondary copper production sector’in China compromising>50%of the global secondary copper production.As part of this project,information on relevant UPOPs from the metal industry have been reviewed and is presented here.This information should also be useful for other(developing)countries for controlling UPOPs releases from metal industries.This review and the information it contains provides a robust resource for policy makers,the industry and researchers to improve secondary copper production to BAT/BEP standards in relation to the reduction of PCDD/Fs and other UPOPs release.The contents include the details required to assist the understanding of the formation of chlorinated UPOPs along with their brominated and brominated-chlorinated analogues.It reviews the international sources of information on BAT/BEP,including the integrated approach considered in the European BAT Reference document,and shows how this can be used to achieve an overall reduction of pollutant releases from the industry.The current national standards of PCDD/F limits to air,water and solid residues have been compiled and are also included.Challenges which need to be addressed,such as the current international lack to consider brominated and mixed bromo-chloro PXDD/Fs which might be more environmentally significant than PCDD/Fs in some facilities e are also discussed.The study includes a brief description of the steps China has taken to change the national regulatory framework and to improve the sustainability of its secondary metal industry.The Stockholm Convention BAT/BEP guidelines recommend consideration of integrated pollution prevention and control and sustainable production as general principles which parties may incorporate when applying the BAT/BEP guidelines and guidance.This holistic approach is considered in the current project and in the improvement of the pilot facilities and will also be considered in the replication of experiences in other facilities.Using this approach ensures the implementation of the Stockholm Convention can contribute to integrated pollution prevention and control,the development of a circular economy and consequently to genuinely sustainable development thus contributing to different sustainable development goals(SDGs).It is hoped this approach will be adopted in other developing and transition economies and thus help to achieve improvements of the secondary metal industry globally.

China’s synergy in the implementation of international conventions on chemicals and waste

The international environmental conventions have become the main effective ways to solve the global environmental issues,which are also the most active convention mechanisms in the world.This paper studies development trend and the implementation of the international environmental conventions on chemicals and wastes in China,such as Basel Convention,Rotterdam Convention,Stockholm Convention and Minamata Convention.Based on the Multilateral Synergy of International Conventions on Chemicals and Wastes,gaps and needs of the management of chemicals and wastes in China,this article put forward proposals for China to implement the coordinated development of these four conventions in the future..