ABSTRACT
Coronavirus disease 2019 (COVID-19) is the most serious infectious disease pandemic in the world in a century, and has had a serious impact on the health, safety, and social and economic development of all mankind. Since the earth entered the "Anthropocene", human activities have become the most important driving force of the evolution of the earth system. At the same time, the epidemic frequency of major human infectious diseases worldwide has been increasing, with more than 70% of novel diseases having zoonotic origins. The review of several major epidemics in human history shows that there is a common rule, i.e., changes in the natural environment have an important and profound impact on the occurrence and development of epidemics. Therefore, the impact of the natural environment on the current COVID-19 pandemic and its mechanisms have become scientific issues that need to be resolved urgently. From the perspective of the natural environment, this study systematically investigated several major issues concerning the environmental transmission and risk prevention of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). From a macroscopic temporal and spatial scale, the research focus on understand the impact of the destruction of the natural environment and global changes on the outbreak of infectious diseases; the threat of zoonotic diseases to human health; the regularity for virus diffusion, migration and mutation in environmental media; the mechanisms of virus transmission from animals and environmental media to humans; and environmental safety, secondary risk prevention and control of major epidemics. Suggestions were made for future key research directions and issues that need attention, with a view to providing a reference for the prevention and control of the global coronavirus disease 2019, and to improving the ability of response to major public health emergencies.
ABSTRACT
During the outbreak of novel coronavirus pneumonia(COVID-19), chlorinated disinfectants were widely used. The chlorinated disinfectants will react with the organic matter in surface water, and the reaction products are chlorinated disinfection by-products(CDBPs). Common CDBPs include halomethanes, haloacetic acids, inorganic haloxate, haloacetonitriles, cyanogen halides,halonitromethane, haloacetaldehyde and other CDBPs.In view of the continued discovery and study of CDBPs, the types and hazards of CDBPs reported in the literature were reviewed. The results indicate that most of the CDBPs have 'three effects' of carcinogenic, teratogenic and mutagenic toxicity, threatening aquatic biosecurity and human health. Although the current research mainly focuses on CDBPs in drinking water,a few studies have confirmed that CDBPs are also detected in surface water. Because large amount of chlorine disinfectants are used during the COVID-19 outbreak,it is recommended to screen the main CDBPs in the surface water containing residual chlorine, conduct targeted monitoring, promot the rational use of disinfectants and strengthen supervision. CDBPs should be added to surface water quality standards and industry wastewater discharge standards. Finally, the secondary environmental impacts on the surface water ecosystems can be avoided.
ABSTRACT
Chlorine disinfectants were widely used during the coronavirus disease(COVID-19). Water quality and human health might be affected by chlorine residues. Residual chlorine and its guideline value was not set in the quality standards of drinking water sources in China. The lack of result evaluation and standards of field rapid analysis methods were also problems to be solved.In order to provide a reference for monitoring and evaluation of residual chlorine in water in public health events, the domestic and international guideline values, laboratory analysis standards and field rapid analysis methods for residual chlorine in drinking water were summarized. The results showed that:(1) The guideline values of residual chlorine in the distribution systems(0.1-2.0 mg/L) and at the point of delivery(0.1-1.8 mg/L), and the maximum concentration of residual chlorine in drinking water(4-5 mg/L) were set by other countries, regions and WHO.(2) Colorimetric and titrimetric methods were considered as standards or recommended analytical methods for laboratories because of their rapid response,stability, high accuracy and high precision. High performance liquid chromatography(HPLC) could also be applied for trace analysis of residual chlorine due to its low detection limit and high sensitivity.(3) Most field rapid analysis and on-line monitoring methods were colorimetric and electrochemical methods, but there was no uniform standard method. The research showed that the maximum concentration of residual chlorine in drinking water in foreign countries, regions or organizations was 5 mg/L. The recommended minimum concentrations for residual chlorine to point of delivery were 0.5 mg/L in high-risk circumstances.It was suggested to carry out the standardization research on the field monitoring methods of water.