Water comprises much of Earth's topmost region, and for us humans, most of our body averaging 60%. Nearly three-quarters of Earth's surface is covered by water including that in solid state near the poles, while the skies contain water vapor in clouds. Regarding humanity, as a convention an adult needs to intake some three liters of fluid, that is usually water, daily to maintain a healthy life. Thus, water and health are intricately linked, at all times... one look at Emergency Evacuation Areas (EEAs) where those people impacted by disasters gather shows how important water is upon keeping such evacuees under duress in hale and hearty conditions. Sanitation at EEAs, said to be quite susceptible to environmental infection by norovirus,* depends on adequate water supply.
Water globally is also home not only to humans but also a wide variety of living things, including microorganisms; for example the marine setting contains myriad of life forms that can withstand extremities in terms of temperature, pressure and other adverse conditions hostile to organic life. As an overall reference just one liter of surface seawater is said to contain on average at least 10 billion bacteria and 100 billion viruses. Of course the lower the salt content the higher becomes the survival rate for living things in general beyond microsized "things" {viruses and obelisks too?}, so logic dictates microbial proliferation rate being increased for "sweet" water.
It is interesting that some relatives to such denizens of the deep ― namely archaea whose acidic saline habitats are next to hydrothermal vents and the like on ocean floors ― have been found flourishing within another hostile environment: the sewer sludge digesters [albeit the "more amenable" versions]... proving even situations on land can be "deep" indeed. At Tohoku University Dept. of Civil and Environmental Engineering, Prof. Daisuke Sano leads R&D activities involving the wastewater aspect. TUNE interviewed Dr. Sano about the Wastewater Information Research Center, of which he is Director.
* Norovirus patients are oft-stricken with dehydration symptoms, thus electrolyte water and intravenous saline solutions would need to be well-stocked as well.
S. Pomeroy (SP): In terms of public health it seems society should learn more about what goes on in the sewerage mains. Can the Wastewater Information Research Center cast a light on the status of sewers beneath our feet?
Dr. D. Sano (DS): Well, this unit is attached to the Civil and Environmental Engineering Department, with the center name implying that it gathers information involving wastewater; we are therefore studying the content of the mains rather than the sewer system. As a focal theme we have been ― since the Center was established several years ago ― looking into the wastewater aspect as it offers a habitat to all types of microorganisms from archaeon/bacterium to virus. Timingwise because of the recent COVID-19 pandemic some spotlight was shed upon the coronavirus [virus classed as enveloped] angle, but in our case the "miniscule round entities" we honed in on were the norovirus [classed as nonenveloped], among other microbes exhibiting † traits of wide tolerance. However, do note that wastewater is "part and parcel" of all the water available on Earth readily as a liquid. It is rather rare to be directly obtainable by humans [naturally-carbonated mineral water by the way being very exceptional] in a "fresh" drinkable form.
† Escherichia coli and Salmonella enterica being widespread ones
https://wastewaterbasedepidemiologicalsurveillance.net/
Website of International Water Association Cluster "Wastewater-based Epidemiological Surveillance"
SP: So, not only do you specialize in the engineering disciplines but as well in microbiology, not to mention environmental science and technology? Do you also keep an eye on endocrine disrupting chemicals (EDCs; in Japan, known as "environmental hormones") or toxic substances then?
DS: I studied here at Tohoku University's Dept. of Civil Engineering, prior to the renaming of the department to encompass Environmental Engineering. Due to good advice I decided to concentrate on water engineering though that meant I had to learn more widely about technology, specifically chemistry and biology among other non-engineering subjects; yes, therefore I count microbiology as a specialist field for myself. I was lucky in that I could access expertise availed nearby to me from university colleagues in biological and chemical fields. That medicine at Tohoku University is considered overall to be at the forefront globally was an additional fortune.
At the Center, our mainstay has until now encompassed pathogens, microbial organisms that trigger diseases in hosts. In fact pathogens are present in water everywhere, on land or at sea... "clear" water is not always potable, it may appear "fresh" but might even be close to being classifiable as "greywater" which means it has to be reclaimed. Although health-related we are not doing any work as to harmful substances or toxic chemicals, excepting toxins ― in terms of drinking water source ― produced by algae within semi-closed water areas.
R&D jobs handled on the side relate to electrical power generation by applying microbial activities such as photosynthesis.
Draft Caption
Photo: Dr. Sano at Sendai City Minami Gamo Wastewater Treatment Plant (courtesy of Manager Takahashi and Chief Sugano of the City's Building Dept.)
SP: When speaking of norovirus, I hear that just disinfection using alcohol might not afford enough protection against this "hardy" type of pathogen. And, it's interesting to see how there are other germs coming to gain in "robustness" recently.
DS: Indeed, germs make for a formidable foe. As it is the sewers offer an incredible battlespace, filled with traps and biofilm... mortal combat ongoing at nano-levels. Yet some survive such scenarios and are able to withstand human endeavors to counter their existence as pathogens through use of antibiotics. Not only viruses but bacteria (like MRSA ‡) also are capable of transforming into "superbugs" ― most wanted today is a means of fighting such Public Enemy No. 1. A crucial yet common aspect of these pathogens is their ability to mutate readily, enabling antimicrobial resistance (AMR) to build up. This is because such pathogens can survive despite various measures like disinfection to inactivate them. Thus in order to develop innovative methods to thwart AMR, vitally important is this unveiling of the mechanisms behind it.
‡ MRSA: Methicillin-resistant Staphylococcus aureus
SP: It is my understanding that your laboratory is delving into the aforementioned mechanisms, in order to counter AMR that endanger lives and limbs inside medical institutions. Actually can you give us an overview?
DS: OK, upon thinking of human health a glimpse of sewer sanitation systems is helpful, classifiable into four types, i.e., drainage management, excreta management, solids management and wastewater management. As regards human hygiene, it aims to prevent spread of germs and to maintain cleanliness; it also revolves around behaviors essential to helping improve sanitation whilst promoting better health habits. The best hygienic practices involve adopting routines such as bathing, washing hands with soap, brushing teeth for oral hygiene plus keeping the home clean. Sanitation systems help to support hygiene, as the infrastructure and systems used to manage waste, from toilets and sewers to recycling facilities and landfills with our forte entailing all except maybe the last. But AMR is a facet which must be factored in, so we hope to shed light on this and establish additional procedures to maximize safety for both patients as well as the public.
SP: Dental care and oral hygiene is of concern personally, I am caries-ridden despite having helped a dental materials outfit; just to think, bacteria including inside the mouth spreading extremely quickly... Being a Houstonian, I wish I had obtained HACCP qualifications! To quote my Mexican amigos, Ay Caramba!
DS: Ah, a Spanish phrase! I studied at a Spanish university, allowing for a more international R&D perspective also. And Houston means space food too. So, you've heard of Hazard Analysis and Critical Control Point, HACCP. In our work we adopted HACCP, the food and pharmaceuticals manufacturing industry standard, since it is part of WHO# guidelines. It is used for monitoring the efficiency of microbial removal and inactivation during processing, rather than for microbiological quality upkeep of final products. Yet because the microbial concentration is low, sensors cannot be used and real-time monitoring is difficult; thus in my laboratory, to solve this problem we propose application of soft sensor technology, in which a target phenomenon is monitored using mathematical models with related but indirect parameters. This can realize a convenient as well as an appropriate assurance of microbiological safety, including viruses, in wastewater treatment plants. Pathogen inactivation efficiency is affected by water quality, in addition to disinfection intensity. If accurate prediction of pathogen inactivation efficiency using disinfection intensity and water quality is made possible, we can also monitor efficacy of pathogen inactivation without resorting to direct measurement of pathogen concentration in water (Kadoya et al., 2021).
# WHO: World Health Organization
Water Sanitation and Health
Water safety planning
WHO Guidelines for drinking-water quality recommend water safety plans (WSPs) as the most effective means of consistently ensuring the safety and acceptability of a drinking-water supply. WSPs require a risk assessment including all steps in water supply from catchment to consumer, followed by implementation and monitoring of risk management control measures, with a focus on high priority risks. This approach enables gradually improving systematic implementation over time where risks cannot be immediately addressed. WSPs should be implemented within a public health context, responding to clear health-based targets and quality-checked through independent surveillance. WSPs are adaptable to all types and sizes of water supply, effectively applied globally as Best Practice for the provision of safe drinking water.
In reverting to EEAs you mentioned earlier, also worth referencing are: 2011 "Manual for Infection Control at Evacuation Centers" and 2014 "Guide to Infection Control Management in Areas Affected by Large-Scale Natural Disasters" among others.