CategoriesCovid-19

How fresh water can be the answer to fight the COVID-19 crisis?

Water is essential for drinking, sanitation, and food production; however, water access and quality are limited for billions of people. Moreover, the COVID-19 pandemic has further amplified the impacts of these water inequalities. Claudia Sadoff and Mark Smith of the International Water Management Institute assess the role of water in the current responses to COVID-19 and future phases of recovery and resilience. Their recommendations range from emergency provision of water to high-risk groups, through developing innovations for water supply and reuse, to scaling strategies for smarter allocation of water to multiple essential uses.

COVID-19 has, like nothing that has gone before, revealed the wiring of the system of the modern, globalized world and how destructive disturbances to those systems can be. Water is a connector across these systems and thus has critical implications for the effectiveness of COVID-19 response efforts and for promoting growth and building resilience in a post-pandemic world.

Water as the Answer

COVID-19 is shining a harsh spotlight on the inequalities, hardships, and global health risks that result from the collective failure to uphold the human right to water and sanitation. In many communities around the world, a lack of water supply and sanitation deprives people of their most basic protections against the spread of the virus.

Improving water, sanitation, and hygiene has the potential to prevent at least 9.1% of the global disease burden and 6.3% of all deaths, according to the World Health Organization (WHO) report Safer Water, Better Health, released before the pandemic. Nevertheless, 4.2 billion go without safe sanitation services and 3 billion lack basic handwashing facilities. In addition, diarrheal diseases caused by waterborne pathogens and poor hygiene inhibit nutrient absorption, so that even those with access to adequate nutrition may face malnutrition. It means that where handwashing is limited and waterborne illness is already common, not only will COVID-19 spread more easily, the amplified state could be lethal.

We should also be aware of the gender implications. In many parts of the world, women and girls spend hours each day fetching water or waiting in crowded queues for water vendors, potentially increasing their risk of exposure to the virus. In addition, if they struggle with these tasks because they are ill or have to care for the sick, it could further compromise their health and food security. Compounding the issue still further, restrictions on movement may lessen the ability to access water at all.

How can we respond to these problems?

In the short term, governments and international organizations should work to ensure access to safe and reliable water supplies and sanitation. It includes emergency provision for underserved communities and protecting women and girls responsible for fetching water from exposure. To address potential supply disruptions, we also need a clear understanding of where and how municipal or rural water infrastructure is coping with pandemic-related spikes in demand. In Ethiopia, IWMI has research underway now to assess the implications of mitigation measures in rural communities.

CategoriesCovid-19 General Awareness

The Water Cycle – What Treatment Professionals You Need to Know to prevent Covid-19?

As the global health community tracks the spread of this virus, it’s important for water and wastewater professionals to keep updated on potential impacts.

It’s hard to miss the headlines. The recent outbreak of novel coronavirus (2019-nCoV or COVID-19) has dominated news cycles in recent weeks. The World Health Organization (WHO) is calling it “public enemy number one.” But what information do we have that is related to coronaviruses in water and wastewater systems? And what can water- and wastewater-system operators do to protect public health?

Modern water and wastewater treatment systems play an important role in public health protection. With the potential for environmental transmission, water and wastewater operators need to know the potential for survival of this type of virus in water and wastewater treatment systems.

Coronaviruses, named for the crown-like spikes on their surface, were first identified in the mid-1960s. Currently, seven coronaviruses are known to infect people and make them ill. Three of these — MERS-CoV, SARS-CoV, and COVID-19 — emerged in the last 20 years and are examples of how some coronaviruses that infect animals can evolve to infect humans. COVID-19 is a new variety of coronavirus and is an enveloped, single-stranded (positive-sense) RNA virus.

So, what is the fate of coronavirus in sewage and wastewater treatment plants? Or in the aquatic environment? And should we be worried about the efficacy of water treatment filtration and disinfection processes for coronavirus removal and inactivation?

The short answer: No — if we take proper precautions and risk considerations.

The long answer: This is a new virus without an extensive body of literature on the effectiveness of water and wastewater treatment processes. And real-life experiences will vary due to water quality and treatment plant details.

According to a 2008 University of Arizona study, coronaviruses have not been found to be more resistant to water treatment than other microorganisms such as E. coli, phage, or poliovirus — which are commonly used as surrogates for treatment performance evaluations. Results from bench-scale studies suggest that the survival of coronaviruses is temperature dependent, with greater survival at lower temperatures. Therefore, coronavirus is expected to be reduced in raw wastewater and surface waters in warmer seasons.

How is it transmitted?

Human viruses do not replicate in the environment. For a coronavirus to be transferred via the water cycle, it must have the ability to survive in human waste, retain its infectivity, and come in contact with another person — most likely via aerosols. Findings suggest that COVID-19 can be transmitted through human waste.

Should a major virus pandemic occur, wastewater and drinking water treatment industries would face increased scrutiny. Utilities would need to respond rapidly to minimize occupational and public health risks based on the available evidence. Wastewater effluents would possibly impact recreation, irrigation, and drinking waters. While wastewater treatment does reduce virus levels, infective human viruses are often detected in wastewater treatment plant effluent.

Information for wastewater treatment plant operators

Typically, human waste entering a sewage system is carried through an underground pipe system to a municipal treatment plant. Wastewater treatment plants receiving sewage from hospitals and isolation centers treating coronavirus patients — and domestic sewage from areas of known large contamination — may have elevated concentrations of viruses. Wastewater is treated by a variety of processes to reduce the pollution impacts on nearby receiving waters (lakes, rivers) and disinfected.

Currently, major data gaps exist on the potential role of the water cycle in the spread of enveloped viruses. The lack of detection methods for these strains of viruses is a main reason this type of information is still relatively unknown. Most detection methods are designed and optimized for non-enveloped enteric viruses, and there just isn’t enough information available.

In general, secondary wastewater treatment is credited with removing 1-log (90 percent) of viruses, though broad studies suggest the level of virus removal is highly variable, ranging from insignificant to greater than 2-log removal (99 percent). Because of this variability, the primary process for the inactivation of viruses in wastewater treatment is chemical disinfection (e.g., chlorination) and/or by ultraviolet light.

Drinking water treatment is an effective barrier

Surface-water treatment plants with upstream wastewater impacts are the most susceptible to having coronavirus contamination in the raw water supply during, and after, an outbreak. Viruses are exposed to several potentially inactivating stresses in surface waters, including sunlight, oxidative chemicals, and predation by microorganisms. Generally, enveloped viruses are more susceptible to common drinking water disinfectants than non-enveloped viruses.

Based on published research, water treatment processes that meet virus removal/inactivation regulations are effective for coronavirus control.

For example, drinking water quality guidelines from Health Canada note conventional treatment with free available chlorine can achieve at least 8-log inactivation of viruses in general. Of course, disinfection performance must be continuously monitored (e.g., turbidity, disinfectant dose, residual, pH, temperature, and flow). Optimized conventional filtration can achieve 2-log (99 percent) virus removal and is just one of many processes water treatment facilities incorporate to make our water safe to drink.

Modern drinking water treatment plants are well equipped to remove and disinfect viruses through filtration and disinfection processes.

So now what?

By and large, these viruses are not considered a major threat for the wastewater and water industries due to their low concentrations in municipal wastewater and high susceptibilities to degradation in aqueous environments. According to new OHSA guidance, there is no evidence to suggest that additional, COVID-19-specific protections are needed for employees involved in wastewater treatment operations.

The WHO found that risk communication and community engagement (RCCE) has been integral to the success of response to health emergencies. Action items related to coronavirus include communicating about preparedness measures and establishing a system for listening to public perceptions to prevent misinformation.

CategoriesCovid-19 General Awareness

Can Ozone Therapy be an option to prevent Covid-19?

The rapid and pandemic outbreak of SARS-CoV-2 causing COVID-19 recognizes in the containment of the infection and in its therapeutic management the two most addressed and challenging topics. Recent guidelines suggest that person-to-person transmission (droplets and aerosol) are the main transmission routes and that, although less likely, also contact with surfaces and objects on which the virus is present can represent a risk. With regard to treatment, many clinical trials are ongoing worldwide, but no specific antiviral treatment is unanimously recognized leaving to supportive care and symptoms management the most recommended approach.

Ozone has extensively been studied in medicine and currently applied at different possible concentrations in various disciplines such as dentistry, dermatology, acute and chronic infectious diseases, and pneumology. Chemically it is formed by a triatomic dynamically unstable molecule of oxygen that in gaseous form has a half-life of about 1 h at room temperature, rapidly reverting to oxygen. Regarding ozone-related risks, as environmental pollutant it has been shown to reduce maximal transpulmonary pressure, increases respiratory rate and decreased tidal volume as well as significantly increases mean airway resistance and specific airway resistance possibly contributing to increased Influenza A infection. Furthermore, it has been shown that the lipid peroxidation operated by high concentration of ozone at the alveolar level can cause strong structural alterations of the surfactant, in a dose and time dependent manner. Strong fusion of lamellar bodies (LBs), associated to the appearance of increasing concentrations of densely coiled LB-like shapes in the alveolar lavage, are resulting ultrastructural changes in type II alveolocites. At the same time, it occurs also a strong reduction of organized tubular myelin structures. This is likely due to the fact that medium-high concentration of ozone induce alveolar lesions as consequence of phospholipid peroxidation, causing time-dependent alterations in the organization of stored, and secreted surfactant membranes; as a result, administration of gaseous ozone must be avoided.

For medical purposes, ozone can be administered parenterally with minimal side effects, beside the only exception of not being injected intravenously as a gas because of the risk of embolism. As a powerful oxidant, when ozone comes into contact with blood or other body fluids, it releases reactive oxygen species (ROS), and lipid oxidation products (LOPs) both of which are responsible for the biological results. The main form of ROS is hydrogen peroxide (H2O2) which is easily transferred from plasma into the cells. When H2O2 abruptly appears above the threshold medical concentration in the cytoplasm of cells it represents the triggering stimulus for the possibly simultaneous activation of different biochemical pathways in erythrocytes, leukocytes and platelets in addition to other numerous biological effects, such as antimicrobial, immunostimulant, and antioxidant ones. H2O2 is then suddenly inactivated into water by the high concentration of glutathione (GSH), catalase (CAT), and glutathione peroxidase (GSH-Px) enzymatic systems, reducing its harmful potential. Although the exact mechanism of action of ozone is far to be fully elucidated, it has been characterized to have different biological properties. For example, it has been showed to facilitate wound healing by promoting the release of oxygen, platelet-derived growth factor and transforming grow factor β. Ozone is also regarded as capable to activate the immune system increasing the production of interferon and interleukin-2 and decreasing tumor necrosis factor (TNF) levels. In addition to this, ozone stimulates both the red blood cell glycolysis rate leading to an increased amount of oxygen released to the tissues and the Krebs cycle resulting in an increased production of ATP. It also reduces significantly NADH concentration and helps to oxidize cytochrome C, thus stimulating oxygen metabolism, as well as it shows anti-inflammatory and possible cytoprotective action interacting with NF-KB and Nrf2 transcription agents. The paradox that ozone exerts an antioxidant response (known as oxidative preconditioning) capable of reversing a chronic oxidative stress is related to the stimulation of production free radical scavengers and cell-wall protectors such as glutathione peroxidase, catalase, and superoxide dismutase.

Through the oxidation of double bonds, ozone possesses the unique ability to inactivate biological contaminants, including viruses. Ozone disrupts the integrity of the bacterial cell walls causing their lysis and death, and is able to effectively control spore germination of various dermatophytes (14, 15). Data obtained throughout years of research suggest that ozone inactivation of viruses occurs primarily in by lipid and protein peroxidation. Lipid peroxidation is initiated by different ROS, including H2O2. Through oxidation of the unsaturation along the hydrocarbon chain of fatty acid component of phospholipid membrane it causes severe structural and functional damage to the lipid bilayer of the plasma membrane. On the other hand, protein peroxidation is due either to interaction of protein with ROS or by interaction with secondary byproducts of oxidative stress; both of them cause irreversible oxidative changes that inhibit normal cellular mechanisms. These include loss of aggregation and proteolysis control, changes in enzyme-substrate binding activities, and modifications in immunogenicity. Protein peroxidation particularly seems to play a key role in the inactivation of non-enveloped viruses, such as adenovirus, poliovirus and other enteroviruses. Murray and coworkers demonstrated few years ago the efficacy of ozone against a variety of simple and complex viruses, including enveloped, non-enveloped, DNA, and RNA ones. Vesicular stomatitis Indiana virus (VSIV), adenovirus type-2 (HAdV-2), and selected strains of herpes simplex virus type-1 (HHV-1), vaccinia virus (VACV), influenza A virus (FLUAV) pools were exposed in vitro to a minimal amount of ozone (from 800 to 1,500 parts per million by volume), and it was effective in inactivating all these viruses. More in detail, enveloped viruses such as VSIV, HHV-1, VACV, and FLUAV showed great sensitivity to ozone while the non-enveloped HAdV-2 was more but not completely resistant to ozone. The results of the study suggest a direct and irreversible damage and destruction of the lipid viral envelope and protein capsid confirming the ability of ozone as a tool for the control of some viruses. Ozone therapy has recently been suggested as a possible economic and easily available further option for Sars-CoV-2 thanks to its immunomodulatory, anti-inflammatory and biocide action and to the nitric oxide associated and dependent antiplatelet effect. About the relationship between ozone and Sars-CoV-2 is also worth noting the “triangle” existing among human angiotensin-converting enzyme 2 (ACE2), that both is a receptor facilitating virus entry and, as fundamental component of renin-angiotensin system, also protects from acute lung injury, and Nrf2 pathway modulation, influencing ACE2 activity and being in turn influenced by ozone. Interestingly, the virus has also been found in substrates other than respiratory secretions, such as fecal swabs and blood, suggesting a possible interaction with the virus in case ozone is in the blood. Recently, the Italian “Istituto Superiore di Sanità” (National Institute of Health) answering to Prof. Franzini, member of “Scientific Society of Oxygen Ozone Therapy” Directive Board, recognized that oxygen-ozone therapy, after Ethical Committee approval and under patient informed consent, could represent a possible option. Remarkably, in this regard, two recent reports of the “Scientific Society of Oxygen Ozone Therapy,” referring to patients affected by COVID-19 undergoing immediately after hospitalization, in addition to standard therapy, also to autohemotherapy with ozonated blood, furnished very encouraging results. Moreover, also other reports hypothesizing the use of ozone in COVID-19 are being progressively undertaken and published.

Gas concentration, route of administration, safety, stage of the disease in which administer it, patients’ selection, contraindications, concomitant administration of antioxidants, etc., are some of the aspects that need to be further addressed with regard to its eventual use in COVD-19 patients, but in the authors opinion ozone therapy is an option that could deserve to be explored while waiting for specific treatments and for a vaccine.