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551.
Jonathan W. Martin 《Ambio》2021,50(3):534
Looking back 50 years at classic literature was a reminder of inspiring discoveries and clever theories that were formative to the field of environmental chemistry, but also of the irreparable costs that persistent global pollutants have had on ecosystems and human society. In my view, these three papers have greatly impacted contemporary science and influenced development of policies that have limited the spread of hazardous contaminants. At the same time, a sobering reality is that reversing decades of past pollution has proven impossible in our lifetime, and global trends are dire for both legacy and emerging contaminants. Lessons in these papers are clear to most environmental scientists, but I argue have not resulted in adequate investment in infrastructure or manpower to enable systematic unbiased searching for pollutants as proposed by Sören Jensen in 1972. Acknowledging that the costs of new global contaminants will be too high, we must incentivize safer chemicals and their sustainable use, increase international exchange of lists of chemicals in commerce, and coordinate international efforts in nontarget screening to identify new contaminants before they circulate the world. 相似文献
552.
Natural and anthropogenic factors can alter bromide concentrations in drinking water sources. Increasing source water bromide concentrations increases the formation and alters the speciation of disinfection byproducts (DBPs) formed during drinking water treatment. Brominated DBPs are more toxic than their chlorinated analogs, and thus have a greater impact on human health. However, DBPs are regulated based on the mass sum of DBPs within a given class (e.g., trihalomethanes and haloacetic acids), not based on species-specific risk or extent of bromine incorporation. The regulated surrogate measures are intended to protect against not only the species they directly represent, but also against unregulated DBPs that are not routinely measured. Surrogates that do not incorporate effects of increasing bromide may not adequately capture human health risk associated with drinking water when source water bromide is elevated. The present study analyzes trihalomethanes (THMs), measured as TTHM, with varying source water bromide concentrations, and assesses its correlation with brominated THM, TTHM risk and species-specific THM concentrations and associated risk. Alternative potential surrogates are evaluated to assess their ability to capture THM risk under different source water bromide concentration conditions. The results of the present study indicate that TTHM does not adequately capture risk of the regulated species when source water bromide concentrations are elevated, and thus would also likely be an inadequate surrogate for many unregulated brominated species. Alternative surrogate measures, including THM3 and the bromodichloromethane concentration, are more robust surrogates for species-specific THM risk at varying source water bromide concentrations. 相似文献
553.
Manwen Zhang Guixian Feng Wenhua Yin Bing Xie Mingzhong Ren Zhencheng Xu Sukun Zhang Zongwei Cai 《环境科学学报(英文版)》2017,29(12):3-10
Since the 2010 s, the authorities of Guangdong province and local governments have enhanced law enforcement and environmental regulations to abolish open burning, acid washing, and other uncontrolled e-waste recycling activities. In this study, ambient air and indoor dust near different kinds of e-waste recycling processes were collected in Guiyu and Qingyuan to investigate the pollution status of particles and polychlorinated dibenzo-pdioxins and furans(PCDD/Fs) after stricter environmental regulations. PM_(2.5) and PCDD/Fs both showed significantly reduced levels in the two regions compared with the documented data. The congener distribution and principal component analysis results also confirmed the significant differences between the current PCDD/Fs pollution characterizations and the historical ones. The estimated total intake doses via air inhalation and dust ingestion of children in the recycling region of Guiyu ranged from 10 to 32 pg TEQ/(kg·day), which far exceeded the tolerable daily intake(TDI) limit(1–4 pg TEQ/(kg·day). Although the measurements showed a significant reduction of the release of PCDD/Fs, the pollution status was still considered severe in Guiyu town after stricter regulations were implemented. 相似文献
554.
Patterns of seasonal and long-term dynamics of the size and structure of the bank vole population were studied in the European
subtaiga subzone, the optimum of the species range. The dynamics of this population proved to undergo complex fluctuations
with cyclic components, which have periods of one year and about three years. The one-year fluctuations of the population
size and structure are accounted for by animal adaptation to seasonal changes in environmental factors. The fluctuations with
the three-year quasi-period are determined by intrapopulation density-dependent mechanisms. 相似文献
555.
Jason P. Marshall 《Journal of Cleaner Production》2011,19(5):424-428
In an attempt to improve the adoption rate of the work conducted at the Toxics Use Reduction Institute Lab, a more comprehensive on-site follow-up assistance program was implemented in 2006. The effort was piloted for trichloroethylene replacement in Rhode Island in conjunction with Environmental Protection Agency (EPA) Region 1.Through hands-on workshops and on-site assistance efforts, the TURI Lab project was able to achieve an 82% reduction in TCE in a two year period. This new methodology for on-site assistance follow-up to the preexisting TURI Lab testing program has been incorporated into the work the Lab conducts for companies in Massachusetts. The Lab had an implementation rate of around 30% without on-site assistance. During the first year of the new process, the adoption rate has jumped to 80% of all companies working with the lab. 相似文献
556.
利用继电器及电容等简单元件设计的一个电机电源相序自动调节装置,保证电源以顺向的固定模式输向电机。 相似文献
557.
论江汉平原以治水为主的国土综合整治对策 总被引:3,自引:1,他引:2
从分析江汉平原自然特点和总结以往治理经验出发,阐明目前水土资源综合开发中存在的问题,提出进一步开展以治水为主的国土综合整治对策。主要就进一步搞好国土综合整治规划、加强工程管理与科学调度、改造渍害田、绿化周围山丘地带和加强基础研究工作等几方面进行了论述,对该地区综合开发有重要参考价值。 相似文献
558.
This paper attempts to compare the relative efficiency across MSW incineration facilities under the three operating modes including government-owned government-operated (GOO), government-owned private-operated (GOPO), and private-owned private-operated (POPO) by using the Data Envelopment Analysis (DEA), and to examine the factor in affecting the efficiency variation. The results show that technical efficiency scores are 0.7538, 0.9046 and 0.9917 for GOO, GOPO and POPO, respectively. An ANOVA is conducted and the analysis result confirms that the operating mode has significant impact on technical efficiencies. A further examination on the operating contracts signed between governments and operating firms of GOPO facilities finds that both the price protection and quantity protection also play vital roles in affecting efficiencies. 相似文献
559.
M. Johannesson S. O. Hansson C. Rudn M. Wingborg 《Journal of environmental management》1999,57(4):267
We have compared three legal and administrative systems of risk management in Sweden, namely those responsible for work environment, environmental protection and chemicals control. Large differences were found in terms of the organisational structure and the general modi operandi of government activities in the three areas. Many of these differences seem to be the result not of deliberate choice, but rather of the lack of coordination between policy areas. One of the most striking differences is the much lower priority assigned to enforcement activities in the environmental than in the occupational health sector. It is concluded that systematic comparisons of experiences from different policy areas can be helpful in improving the efficiency of risk management. 相似文献
560.
环境管制与企业竞争力之间的关系问题成为近几年来国内外广泛关注的热点问题之一,许多学者对此问题的看法各不相同.对已有的研究成果进行了系统分类和归纳总结,旨在揭示政府的环境管制与企业竞争力之间的关系及作用机制,为促进企业的经济发展与环境保护的协调发展和可持续发展提供改革的理论依据. 相似文献