Wednesday, June 7, 2023

The Power of Wastewater-Based Epidemiology

Wastewater surveillance is a valuable tool for monitoring public health and detecting infectious diseases. It plays a crucial role in understanding the interconnection between human activities, public health, and environmental well-being. Wastewater contains a wide range of pollutants, including pathogens, chemicals, pharmaceuticals, and microplastics, which can pose risks to both human and environmental health. As the field progresses, innovative methodologies are continuously being developed, providing advancements in time and cost efficiency for analysis. 

by author, with ChatGPT & Bing image Creator

Wastewater-based epidemiology (WBE) emerged in 2001 as a method to monitor drug abuse, and it has since evolved to include various technological advancements in substance detection, providing near real-time and unbiased insights to prevent future drug epidemics. The COVID-19 pandemic has sparked a renewed interest in WBE and highlighted the link between wastewater and population health. The UC Merced COVIDpoops dashboard and the Biobot Network of Wastewater Treatment Plants are examples of global initiatives monitoring SARS-CoV-2 RNA and monkey pox virus DNA in wastewater, with data generated from numerous sites and representing millions of people. 

Wastewater surveillance is a rapidly advancing field with immense potential for enhancing public health, disease prevention, and response to future health crises. By analyzing wastewater, we can gain valuable insights into the health of communities and effectively monitor infectious diseases, antimicrobial resistance, and illicit drug consumption.

WBE has proven to be a valuable tool in detecting various substances and environmental factors in our communities. Beyond its most known applications in monitoring illicit drugs, COVID-19 and enteric viruses, WBE has expanded to encompass the detection of various pharmaceuticals, dietary biomarkers, and environmental contaminants such as metals. By providing a holistic understanding of a city's metabolism, WBE contributes to our knowledge of population health and environmental well-being. As we continue to harness the power of WBE, it is crucial to consider environmental justice and equity when determining the locations for monitoring. With continued advancements and broader implementation, WBE holds the potential to revolutionize public health, enhance environmental monitoring, and promote a more sustainable and equitable future.


Cheng, Q., Chunhong, Z. & Qianglin, L. Development and application of random forest regression soft sensor model for treating domestic wastewater in a sequencing batch reactor. Sci Rep 13, 9149 (2023).

Demian S. Barcellos, Carlos E.R. Barquilha, Pâmela E. Oliveira, Mario Prokopiuk, Ramiro G. Etchepare, How has the COVID-19 pandemic impacted wastewater-based epidemiology?, Science of The Total Environment, Volume 892, 2023, 164561, ISSN 0048-9697,

Gitter A, Oghuan J, Godbole AR, Chavarria CA, Monserrat C, Hu T, Wang Y, Maresso AW, Hanson BM, Mena KD and Wu F (2023), Not a waste: Wastewater surveillance to enhance public health. Front. Chem. Eng. 4:1112876.

Rhodes T, Lancaster K. Early warnings and slow deaths: a sociology of outbreak and overdose. International Journal of Drug Policy. 2023 Jul 1;117:104065.

Naughton CC, Roman Jr FA, Alvarado AG, Tariqi AQ, Deeming MA, Kadonsky KF, Bibby K, Bivins A, Medema G, Ahmed W, Katsivelis P. Show us the data: global COVID-19 wastewater monitoring efforts, equity, and gaps. FEMS Microbes. 2023;4:xtad003.

Friday, January 20, 2023

Participatory Environmental Health Research

The field of environmental health is facing increasingly complex challenges that require innovative approaches to research and decision-making. One promising strategy is to expand the participation of the community, which has the potential to enhance the effectiveness and relevance of health sciences. Although this approach is relatively new in the field of environmental health, it has a long history of success in other scientific disciplines such as ornithology, where citizen science initiatives like bird counts have been taking place for over a century, and geography where land use surveys were carried out by school children in Britain in the 1930s and 1940s. 

Crowdsourcing could achieve in months what would take years through conventional research approaches. Passive Citizen science and digital citizen panels speed up research by increasing the numbers of participants and data points, making data collection more cost-effective and efficient, and by improving the engagement and participation of community members. “Extreme” citizen science and quantified-self approaches would go even further to involve the public in co-creation, co-design, data analysis, interpretation, and, ultimately, public health actions. Awareness to stay fit and healthy and the use of fitness trackers continues to rise, especially among a growing aging population with disposable income to burn, but this hasn't yet resulted in the rise of Collaboratory Health Research

Crowdsourced online information has been used for tracking the spread of biological contaminants and infectious diseases for several years now. While games like Flu-City, and Big Tech- or government-supported programs like HealthMap, FluTrackingEPA maps, many other apps ceased to exist. Sickweather, launched in 2011 reached an audience of 10 million daily active users during the heights of the COVID-19 pandemic, filed for bankruptcy in 2022. Apparently their "NoPeek” privacy solution wasn't sufficient for gaining citizens’ trust and engagement. 

Despite the early promise of passive crowdsourcing, it often struggles with accuracy issues. For example, Google Flu Trends (launched in 2008 and used aggregated search query data, initially claiming 97% accuracy when compared to CDC data) was criticized for not being able to predict the 2009 H1N1 pandemic and overestimating influenza-like activity in the United States during the 2012–2013 flu season. Web-based crowdsourcing was used to digitize geospatial information on thousands of public drinking water service areas in California.

Controlled community-team-based studies (active crowdsourcing) also report larger numbers for disease incidence and side effects of drugs (adverse event preventing from daily activities). This, however, is not an overestimate - and it is in line with recent findings of circulating unbound spike protein after COVID-19 vaccination. 

Communities are better able to provide key ground-truthed information. People's perception of environmental health hazards may not be consistently associated with their health outcomes since their health vulnerabilities vary, depending on the age, gender and other variables. Citizen scientists can, however, operate sensors to collect more objective and accurate data - continuously and in real-time. In our community-based studies, these were gut microbiome, urine, blood, environmental and exhaled air samples. The development of portable air monitors, sensing platforms for detection of various inorganic, organic, and biological analytes and home urine labs has made it possible to track changes in environmental health on a global scale. While there are limitations to sensor technology in terms of sensitivity and selectivity, they continue to evolve along with participatory health approaches and have the potential to greatly enhance our understanding of the impact of the environment on human health.


Jeanjean M, Dron J, Allen BL, Gramaglia C, Austruy A, Lees J, Ferrier Y, Periot M, Dotson MP, Chamaret P, Cohen AK. Participatory environmental health research: A tool to explore the socio-exposome in a major european industrial zone. Environmental Research. 2023 Feb 1;218:114865.

Gabashvili IS The Incidence and Effect of Adverse Events Due to COVID-19 Vaccines on Breakthrough Infections: Decentralized Observational Study With Underrepresented Groups JMIR Form Res 2022;6(11):e41914 doi: 10.2196/41914 PMID: 36309347 PMCID: 9640199

Gabashvili IS Cutaneous Bacteria in the Gut Microbiome as Biomarkers of Systemic Malodor and People Are Allergic to Me (PATM) Conditions: Insights From a Virtually Conducted Clinical Trial JMIR Dermatol 2020;3(1):e10508 doi: 10.2196/10508

Siira E, Wolf A. Are digital citizen panels an innovative, deliberative approach to cardiovascular research? Eur J Cardiovasc Nurs. 2022 Apr 9;21(3):287-291. doi: 10.1093/eurjcn/zvab132. PMID: 35030241.

English PB, Richardson MJ, Garzón-Galvis C. From crowdsourcing to extreme citizen science: participatory research for environmental health. Annual review of public health. 2018 Apr 1;39:335-50.

Liu Y, Kwan MP, Kan Z. Inconsistent Association between Perceived Air Quality and Self-Reported Respiratory Symptoms: A Pilot Study and Implications for Environmental Health Studies. International Journal of Environmental Research and Public Health. 2023 Jan 13;20(2):1491.

Gabashvili IS. Effects of diet, activities, environmental exposures and trimethylamine metabolism on alveolar breath compounds: protocol for a retrospective case-cohort observational study medRxiv 2021.01.25.21250101; doi:

Khizar S, Zine N, Jaffrezic-Renault N, Elaissari A, Errachid A. Prospective analytical role of sensors for environmental screening and monitoring. TrAC Trends in Analytical Chemistry. 2022 Aug 3:116751.

Monday, December 19, 2022

The Environmental Health Benefits of Self-Cleaning Houses

In today's fast-paced world, it seems that we are constantly fighting against the pull of entropy, trying to keep our built environments free of unwanted matter: dust and dirt, mold and other substances that may pose a risk to the health and well-being.

In the 19th century, Oscar Wilde famously stated, "We live, I regret to say, in an age of surfaces." -  generating pollution, unwanted microorganisms and allergens.  As automation becomes increasingly prevalent in our lives, it's easy to wonder why some maintenance tasks are still performed by human workers. Despite the proliferation of "smart" technologies, many of the futuristic features we were promised in model homes and prototypes have yet to become a reality. From 3D printers for disposable dinner plates to virtual girlfriends that can cook and clean, it seems that we are still waiting for the advanced home technologies predicted in science-fiction. In the past, we have seen many interesting ideas such as Frances Gabe's self-cleaning home in Oregon and the rounded corners proposed by Buckminster Fuller and Peter and Alison Smithson to improve cleaning. 

Frances Gabe, known for her innovative approach to housework in the 1980s, wanted to make housework extinct. As a busy mother of two, she grew tired of the never-ending cycle of cleaning and built a self-cleaning house that used sprinklers and drying machines to channel water into drains that led outside. Gabe received a lot of attention and notoriety during the heyday of her self-cleaning house, but later faded from the public eye. She was known to be a bit of a recluse and had a reputation for being "difficult," according to some friends and neighbors. Despite her innovative approach to housework, Gabe's life ended rather anonymously, having divorced and outlived her two children. Unfortunately, an earthquake in 2001 severely damaged the technology in the self-cleaning house and it is now used as a "wintering habitat for honeybee colonies and campground for traveling cyclists" by its current owner. 

While Gabe's self-cleaning house may have been ahead of its time, today we are seeing more and more innovations in home cleaning technology, such as automatic vacuum cleaners and self-cleaning toilets. The latter technology can reduce the risk of cross-contamination and the need for harsh chemicals.

As Sigmund Freud suggested, our jokes often reveal our unconscious desires, and this may explain why the idea of a self-cleaning car was such a hit when Subaru introduced it as an April Fool's joke in 2013. The "Carbon electric paint" technology was supposed to use ambient air and a surge of electricity to clean the car's exterior. It seemed that people wanted the self-cleaning feature even more than self-driving.

According to a survey conducted by the American Cleaning Institute in 2018, the average American spends approximately six hours per week cleaning their home, with over a quarter of respondents spending over seven hours straightening up. Despite this effort, many of us still wonder if we are cleaning enough and if we are doing it correctly. Our most regularly cleaned fixtures are toilets and floors, and our most dreaded cleaning tasks are typically cleaning the bathroom, followed by kitchen cleaning, dusting, mopping, and doing the laundry. 

But while some fictional homes, like those in Back to the Future and Blade Runner, have been able to incorporate robots and automated features to assist with tasks like feeding pets and preparing meals, it seems that we are still far from achieving a truly self-sufficient home. Perhaps the closest we have come to realizing some of these futuristic home technologies is through the use of smart home assistants, like speakers that can turn on lights or set up a virtual card table for a weekly game of bridge. While these technologies are certainly convenient, they are still a far cry from the kind of self-sustaining homes that we were promised in the past. 

As technology continues to advance, it is likely that we will see "smarter" or even "living" houses. Researchers are working on developing robots that can perform tasks like laundry and dishwashing, and there are even companies exploring the use of drones for tasks like roof inspections and window cleaning. It will be interesting to see how these technologies evolve and how they can be used to make our lives easier in the future. Maybe one day we'll even be able to leave behind no-longer needed cleaning tools for good.

IG: Special thanks to OpenAI's Assistant for their help with organizing my old notes and writing this article.

Wednesday, September 21, 2022

Designing food environment to improve behavior

Breaking a bad habit takes a lot of willpower. The environment - family, significant others, friends, coworkers, classmates, neighbors, personal physician, religiosity/spirituality, media - can provide support or serve as a barrier to changing behavior.  

The eating environment is central to one's health since it can influence not only individual's weight—for good or for bad, but also put them at risk for the development of many diseases and conditions, such as arthritis, diabetes, and heart disease. 

Recent review analyzed 357 studies focused on the digital and physical food environments. The dimensions studied were (1) Food availability, (2)
Food prices; (3) Vendor and product properties (in terms of nutritional composition, overall quality, level of processing, etc., (4) Marketing and regulation; (5) Food accessibility (referring to individual access in terms of physical distance to shops, time, modes of transportation and daily mobility); (6) Affordability; (7) Convenience and, finally, (8) Desirability. 

Most studies focused on this topic, followed by research on vendors and their marketing strategies (especially unhealthy food marketing to children), although cumulatively there was more emphasis on external than on personal domain.

One systematic review (Rounsefell et al, 2020) indicated that digital food environment was, indeed, influencing eating patterns - for example, when peers or celebrities posted idealized images). Food-related posts on social media also influenced satiety, by amplifying feelings of hunger and neglect of satiety clues. Digitalization has the potential to increase food availability and may even provide less expensive options to specific products but is still adding a new cost to buying food, in the form of delivery fees. 

Public health interventions achieve medium-sized influences on food behavior in children and almost negligible in adolescents. Mobile apps might be effective, but the most effective behavior change technique is yet to be found. Goal setting, problem solving, periodic goal/outcome reviews and feedback, self-monitoring of behavior, social support, information about health consequences, and behavior practice/rehearsal could all be effective to some extent. But the use of smartphone weight loss apps is still not sufficient to produce clinically meaningful health outcomes.

Behavioral interventions encourage people to act, but the actions are controlled by the individual. ~25% of individuals are influenced by existing wearable and mobile app solutions, but 75% need something better. Personalized combination of interventions, individual psychology and activity environment along with a better integration of human element are needed for designing successful digital interventions to improve health-related behavior. 


Vargas‐Garcia EJ, Evans CE, Prestwich A, Sykes‐Muskett BJ, Hooson J, Cade JE. Interventions to reduce consumption of sugar‐sweetened beverages or increase water intake: evidence from a systematic review and meta‐analysis. Obesity Reviews. 2017 Nov;18(11):1350-63.

Rounsefell K, Gibson S, McLean S, Blair M, Molenaar A, Brennan L, Truby H, McCaffrey TA. Social media, body image and food choices in healthy young adults: A mixed methods systematic review. Nutrition & Dietetics. 2020 Feb;77(1):19-40.

Al Zuhaibi K, McCullough F, Salter AM. Effectiveness of health and fitness smartphone applications to improve dietary habits and physical activity in Omani adults. Proceedings of the Nutrition Society. 2017;76(OCE2).

Chew HSJ, Koh WL, Ng JSHY, Tan KK Sustainability of Weight Loss Through Smartphone Apps: Systematic Review and Meta-analysis on Anthropometric, Metabolic, and Dietary Outcomes J Med Internet Res 2022;24(9):e40141 doi: 10.2196/40141 PMID: 36129739

Tuesday, February 1, 2022

Who Benefits the Least from the COVID-19 Vaccines

Factors associated with inadequate vaccine responses in patients with breakthrough infections are still not fully understood. Studies show that genes, environment (such as air pollution), and gene-environmental interactions all influence Coronavirus disease. Less research has been done for the vaccines. 

An earlier study [Boyarsky et al, 2021]  found that 46% of transplant patients had no antibody response after two doses of messenger RNA (mRNA) vaccines. Several medical case reports about fatal breakthrough  infections listed chronic migraine, obesity, autoimmune conditionsdiabetes, atrial fibrillation, myeloma (with anti-BCMA CAR-T therapy), arterial hypertension and old age among pre-existing conditions.  Some fatal breakthroughs, however, had no apparent underlying causes. 

A new study used real-world data to evaluate risk factors of impaired antibody response to SARS-CoV-2 mRNA vaccines in individuals with chronic medical conditions evaluated in a respiratory specialty clinic. The percentage of patients without antibodies detected was as follows:

- 14% in asthma 
- 15% in COPD
- 19% in Sarcoidosis
- 36% in Interstitial lung diseases
- 37% in Rheumatic diseases
- 48% in Congestive Heart Failure (CHF). 

More than a fifth of patients with chronic medical conditions may still have insufficient levels of antibodies to fight COVID-19 even after a second mRNA vaccine dose. Interstitial lung disease and congestive heart failure are two independent risk factors for low antibody response to COVID vaccination. These patients tended to be older — between 65 and 95 years old with a median age of 80.5 — and had preexisting comorbidities, such as cardiovascular disease and Type 2 diabetes. A subset of patients was also on immunosuppressive drugs that may affect vaccine efficacy. 

Anther study that analyzed fatal breakthrough cases came with the following risk order: Overweight/Obesity; Chronic cardiac disease; Diabetes mellitus, Chronic neurologic disease; Chronic kidney disease; Chronic liver disease; Chronic pulmonary disease; Immunosupression.  Pregnancy was shown to double the risk of breakthrough infection. 

Note that the mean age of study population was 62 years and the individuals received two doses of mRNA vaccines. Newer study shows that advanced age is one of major risk factors of fatal breakthrough COVID-19 even after an additional booster dose. 

CDC data, sourced from more than two dozen states, shows that between April and June, a total of 77,000 breakthrough cases and 1,500 breakthrough deaths were recorded, compared to more than 1.74 million breakthrough cases and 15,000 deaths recorded between July and the first week of November. It is unclear exactly how many of these people had also been boosted. As of October 12, 2021, there have been at least 31,895 individuals with SARS-CoV-2 breakthrough infections who were hospitalized or died in the United States. 


Boyarsky BJ, Werbel WA, Avery RK, Tobian AA, Massie AB, Segev DL, Garonzik-Wang JM. Antibody response to 2-dose SARS-CoV-2 mRNA vaccine series in solid organ transplant recipients. Jama. 2021 Jun 1;325(21):2204-6.

Juthani PV, Gupta A, Borges KA, Price CC, Lee AI, Won CH, Chun HJ. Hospitalisation among vaccine breakthrough COVID-19 infections. The Lancet Infectious Diseases. 2021 Nov 1;21(11):1485-6.

Shu-Yi Liao et al, Impaired SARS-CoV-2 mRNA vaccine antibody response in chronic medical conditions: a real-world analysis, Chest (2022). DOI: 10.1016/j.chest.2021.12.654

Saturday, January 1, 2022

Evolution of Viruses

All living beings are constantly adapting and evolving in many different ways. Genetic evolution happens because mutations - wrong building blocks of DNA - are randomly introduced during the copying and repair of genetic material. Not all mutations are meaningful, but those that affect cellular processes or lead to amino acid changes, can change the organism’s fitness - the ability to replicate and transmit and strive in different environments. Evolution can also happen through recombination. It is much faster than one nucleotide at a time and the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) - first identified in 2019 - is especially good in using this mechanism. 

 The original SARS-CoV-2 progressively disappeared in subsequent waves of mutated variants. 

Single nucleotide mutations started to arise and were circulating in other sequences months before new variants of concern - such as alpha - B.1.1.7 - took off, likely due to recombination events.

The Omicron - B.1.1.529  - likely picked genetic material from the common cold virus in a SARS-CoV-2 infected individual.  

How SARS-CoV-2 will evolve from here is uncertain. The current SARS-CoV-2 pandemic is fostered by asymptomatic and other types of unrecognized cases. This variety combined with mounting immunity could reduce pathogenicity. But recombination between Delta and Omicron is not out of the question and this could create a super variant.

Will the world find better ways to monitor and prevent infections? Perhaps. Scientists proposed many approaches such as testing wastewater and sampling air in public spaces. Another interesting approach is a voice analysis that could discriminate between positive COVID-19 patients, recovered COVID-19 patients and healthy individuals. Further studies will validate this and other screening technologies for effective surveillance and prevention of threats to public health.


Freer G, Lai M, Quaranta P, Spezia PG, Pistello M. Evolution of viruses and the emergence of SARS-CoV-2 variants. The new Microbiologica. 2021 Dec 19;44(4).  [preprint]

Focosi D, Maggi F, Franchini M, McConnell S, Casadevall A. Analysis of Immune Escape Variants from Antibody-Based Therapeutics against COVID-19: A Systematic Review. International Journal of Molecular Sciences. 2022;23(1):29.

Robotti C, Costantini G, Saggio G, Cesarini V, Calastri A, Maiorano E, Piloni D, Perrone T, Sabatini U, Ferretti VV, Cassaniti I. Machine learning-based voice assessment for the detection of positive and recovered COVID-19 patients. Journal of Voice. 2021 Nov 26.

Tuesday, September 7, 2021

A Fresh Air Look at Ventilation

Environmental factors contribute to the spread of microorganisms causing diseases. Sunlight can kill viruses in minutes, while increased air pollution could be one of the risk factors of more severe outcomes. Humidity is also thought to be important. A team of scientists from Northeast US analyzed COVID-19 cases from 2669 counties and found that cold and dry weather and low levels of ultraviolet radiation are moderately associated with increased SARS-CoV-2 transmissibility, with humidity playing the largest role. 17.5% of the virus’ reproductive number was attributable to meteorological factors, with temperature accounted for 3.73%, humidity accounted for 9.35%, and UV radiation for 4.44%. This is in line with earlier findings about SARS-CoV-2 being less stable at higher humidity and warmer temperatures in human nasal mucus and sputum. Like in previous environmental studies, however, these fractions were not the same everywhere and were higher in northern counties. 

20 years ago, American scientists Wells and Riley developed a model of the airborne transmission of infectious diseases such as tuberculosis and measles. A novel modified version of this model was used to estimate the impact of relative humidity on the removal of respiratory droplets containing infectious virus particles. The results showed that this impact depended on the ventilation rate and the size range of virus-laden droplets.  It was concluded that increasing the ventilation rate is more beneficial, while installing and running humidifiers may not be an efficient solution to reduce the risk of COVID-19 disease in indoor spaces. 

A popular metric for airflow is Air Changes per Hour (ACH, also called Air Change Rate).  It tells how many times the air within a space can be replaced with fresh air each hour. Increasing the ventilation rate from 0.5 ACH to 6 ACH was predicted to decrease the infection risk by half. Studies of US houses and apartments found typical ACH values between 0.5 and 2.0 (with open windows). 4.0 ACH is the minimum air exchange rate acceptable for commercial buildings, but 1.5 ACH is the reality for most schools. Opening a car window raises ACH to 6.  Natural ventilation combined with novel technologies could help to increase fresh air intake with minimal energy cost.

Virus clouds can, indeed, be dispersed with some fresh, clean air. But fresh air isn’t going to stop the spread of microorganisms in high-density crowds. Effective ventilation is only one of basic infection control strategies along with hand/environmental hygiene, social distancing, case surveillance and other evidence-based measures. 


Aganovic A, Bi Y, Cao G, Drangsholt F, Kurnitski J, Wargocki P. Estimating the impact of indoor relative humidity on SARS-CoV-2 airborne transmission risk using a new modification of the Wells-Riley model. Building and environment. 2021 Aug 23:108278.

Ma Y, Pei S, Shaman J, Dubrow R, Chen K. Role of meteorological factors in the transmission of SARS-CoV-2 in the United States. Nature Communications. 2021 Jun 14;12(1):1-9.