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Rasha Maal-Bared

    Rasha Maal-Bared

    Coastal waters, surface waters, and groundwater are impacted by wastewater and stormwater discharges, as well as agricultural flows containing animal waste and nutrients. A One Water approach posits that components of the water system... more
    Coastal waters, surface waters, and groundwater are impacted by wastewater and stormwater discharges, as well as agricultural flows containing animal waste and nutrients. A One Water approach posits that components of the water system have overlapping and interactive impacts on other aspects of the system, for which a comprehensive approach to water management is needed to further inform public health decisions. Current frameworks for monitoring wastewater effluent and recreational surface waters include the measurement of fecal indicator bacteria. Although viral pathogens are likely to be transported further and can survive longer than bacterial pathogens, virus monitoring is not required for recreational waters. A scientific consensus is emerging that the use of bacterial indicators alone does not account for nor represent the health risks associated with viral pathogens due to the differences in the fate and transport of bacterial versus viral pathogens in wastewater treatment, surface water, and groundwater. Furthermore, it is likely that the public health risk associated with these waterborne pathogens is variable and diverse. For example, under drought conditions, effluents of urban water systems can comprise most of the dry weather flow in downstream waters, which are often used as sources of drinking water. This de facto reuse could increase viral risk for the end users of this water. A One Water approach will aid in protecting the health of the public from waterborne pathogens, regardless of where those pathogens entered the water system. In this review, we assert that monitoring for fecal indicator viruses can complement the monitoring of bacterial indicators, thereby improving public health protections. Bacteriophages have the strongest research foundation and correlation with viral pathogens along with some prediction power for risk to human health. Methods for detecting and quantifying coliphages are briefly summarized, as are challenges in the implementation of testing. Key knowledge gaps and research priorities are discussed so that the potential value and limitations of coliphage monitoring can be better addressed and understood.
    Following the Earth Summit in 1992, Cuba designed and implemented a variety of programs, administrative structures, and public awareness activities to promote sound environmental management and sustainable development. This came shortly... more
    Following the Earth Summit in 1992, Cuba designed and implemented a variety of programs, administrative structures, and public awareness activities to promote sound environmental management and sustainable development. This came shortly after the fall of the Soviet Union and the strengthening of the US blockade in 1990, which resulted in a 35% drop in Cuban GDP. This period, referred to as the Special Period, witnessed a decrease in many environmentally damaging activities both by choice and by necessity, but also resulted in many decisions to resuscitate the Cuban economy. The purpose of this work was to compare and rank the environmental risks Cuba faced before and during the Special Period (1990-2000) using two Comparative environmental risk assessments (CERAs). To do so, an ecosystem integrity risk assessment matrix was constructed with 42 risk end points. The matrix assessed the risk posed by 17 problem areas including air pollution, water contamination, solid waste sites, pesticides and ecosystem degradation. The risks were calculated using five criteria: area affected, vulnerability of affected population, severity of impact, irreversibility of effect and uncertainty. To construct this matrix, both literature reviews and expert interviews in Cuba were conducted in 2000. The results showed a general decrease in risk scores during the Special Period. Before the Special Period, high risks were posed by: terrestrial degradation and industrial wastewater and sludge, followed by freshwater degradation, surface water stressors, and pesticides. After the Special Period, industrial wastewater and sludge and pesticides were no longer high-risk areas, but municipal wastewater and marine coastal degradation ranked higher than previously. Also, the risk endpoints most stressed after 1990 were affected by activities controlled by the government, such as mining and tourism, and lack of infrastructure. Therefore, the claims that public environmental education is the main pathway to sustainable development in Cuba seem uninformed and other management practices should be evaluated.
    Wastewater surveillance of SARS-CoV-2 has become a promising tool to estimate population-level changes in community infections and the prevalence of COVID-19 disease. Although many studies have reported the detection and quantification of... more
    Wastewater surveillance of SARS-CoV-2 has become a promising tool to estimate population-level changes in community infections and the prevalence of COVID-19 disease. Although many studies have reported the detection and quantification of SARS-CoV-2 in wastewater, remarkable variation remains in the methodology. In this study, we validated a molecular testing method by concentrating viruses from wastewater using ultrafiltration and detecting SARS-CoV-2 using one-step RT-qPCR assay. The following parameters were optimized including sample storage condition, wastewater pH, RNA extraction and RT-qPCR assay by quantification of SARS-CoV-2 or spiked human coronavirus strain 229E (hCoV-229E). Wastewater samples stored at 4 °C after collection showed significantly enhanced detection of SARS-CoV-2 with approximately 2–3 PCR-cycle threshold (Ct) values less when compared to samples stored at −20 °C. Pre-adjustment of the wastewater pH to 9.6 to aid virus desorption followed by pH readjustment to neutral after solid removal significantly increased the recovery of spiked hCoV-229E. Of the five commercially available RNA isolation kits evaluated, the MagMAX-96 viral RNA isolation kit showed the best recovery of hCoV-229E (50.1 ± 20.1%). Compared with two-step RT-qPCR, one-step RT-qPCR improved sensitivity for SARS-CoV-2 detection. Salmon DNA was included for monitoring PCR inhibition and pepper mild mottle virus (PMMoV), a fecal indicator indigenous to wastewater, was used to normalize SARS-CoV-2 levels in wastewater. Our method for molecular detection of SARS-CoV-2 in wastewater provides a useful tool for public health surveillance of COVID-19.
    We read with great interest the work by Wright and Adhikari on “Utilizing a National Wastewater Monitoring Program to Address the U.S. Opioid Epidemic: A Focus on Metro Atlanta, Georgia” [...]
    Wastewater-based testing (WBT) for SARS-CoV-2 has rapidly expanded over the past three years due to its ability to provide a comprehensive measurement of disease prevalence independent of clinical testing. The development and simultaneous... more
    Wastewater-based testing (WBT) for SARS-CoV-2 has rapidly expanded over the past three years due to its ability to provide a comprehensive measurement of disease prevalence independent of clinical testing. The development and simultaneous application of the field blurred the boundary between measuring biomarkers for research activities and for pursuit of public health goals, both areas with well-established ethical frameworks. Currently, WBT practitioners do not employ a standardized ethical review process (or associated data management safeguards), introducing the potential for adverse outcomes for WBT professionals and community members. To address this deficiency, an interdisciplinary group developed a framework for a structured ethical review of WBT. The workshop employed a consensus approach to create this framework as a set of 11-questions derived from primarily public health guidance because of the common exemption of wastewater samples to human subject research consideration...
    Utilities rely on reliable and robust monitoring systems to inform decisions around asset operation and management in the drinking water distribution system (DWDS) to deliver high quality, biologically stable drinking water to consumers.... more
    Utilities rely on reliable and robust monitoring systems to inform decisions around asset operation and management in the drinking water distribution system (DWDS) to deliver high quality, biologically stable drinking water to consumers. However, traditional culture-based testing methods present challenges that make the timely detection of regrowth in the DWDS difficult. This study reports the results of an extensive adenosine triphosphate (ATP) monitoring campaign—a non-regulated parameter—in an urban, chloraminated drinking water system that analyzed over 5000 samples from two drinking water treatment plants (DWTPs), associated DWTP reservoirs, twelve outlying reservoirs and the DWDS between 2019–2022. ATP concentrations increased significantly between the two DWTP reservoirs and outlying reservoirs but decreased between the outlying reservoirs and DWDS samples. Relationships between ATP concentrations and other water quality variables varied depending on sampling location. Hetero...
    Quantitative microbial risk assessments (QMRAs) present an opportunity to systematically assess risk to wastewater treatment plant (WWTP) workers and mitigate work-related infectious diseases. However, while QMRAs often explore the... more
    Quantitative microbial risk assessments (QMRAs) present an opportunity to systematically assess risk to wastewater treatment plant (WWTP) workers and mitigate work-related infectious diseases. However, while QMRAs often explore the impacts of aeration or treatment mechanism, or the use of controls to mitigate risk (e.g., ventilation, personal protective equipment (PPE)), fewer studies address other variables, such as differing tasks across plants, time spent conducting these tasks or size of plant. QMRA approaches also vary substantially in their findings and recommendations. The objective of this paper is to provide a risk-based wastewater worker task characterization for urban, municipal and industrial WWTPs along with mitigation measures. Routine tasks fell into five categories in ascending order of exposure and risk, Type A being the lowest and Type E being the highest. Percentage of full-time equivalent time spent on each task category was estimated, along with amount of wastew...
    Intro: In Canada, Giardia and Cryptosporidium are the main etiologic agents of waterborne outbreaks and related illness. It has been predicted that climate change will lead to rises in temperature and increases in severity and frequency... more
    Intro: In Canada, Giardia and Cryptosporidium are the main etiologic agents of waterborne outbreaks and related illness. It has been predicted that climate change will lead to rises in temperature and increases in severity and frequency of rainfall events and droughts. Therefore, it is important to understand the impacts of these variables on the presence and distribution of Cryptosporidium and Giardia in raw water sources. Objective: The objective of this study is to: a) compare the distribution of Cryptosporidium and Giardia at two sites on the North Saskatchewan River - intakes of E.L. Smith and Rossdale Water Treatment Plants in Edmonton- between 2012 and 2014; b) determine if various chemical, physical or biological water quality variables are significantly correlated with Cryptosporidium and Giardia presence in surface water; and c)construct a multivariate regression model to predict presence of Cryptosporidium and Giardia in the North Saskatchewan River when possible. Methods...
    Research Interests:
    Following the Earth Summit in 1992, Cuba designed and implemented a variety of programs, administrative structures, and public awareness activities to promote sound environmental management and sustainable development. This came shortly... more
    Following the Earth Summit in 1992, Cuba designed and implemented a variety of programs, administrative structures, and public awareness activities to promote sound environmental management and sustainable development. This came shortly after the fall of the Soviet Union and the strengthening of the US blockade in 1990, which resulted in a 35% drop in Cuban GDP. This period, referred to as the Special Period, witnessed a decrease in many environmentally damaging activities both by choice and by necessity, but also resulted in many decisions to resuscitate the Cuban economy. The purpose of this work was to compare and rank the environmental risks Cuba faced before and during the Special Period (1990-2000) using two Comparative environmental risk assessments (CERAs). To do so, an ecosystem integrity risk assessment matrix was constructed with 42 risk end points. The matrix assessed the risk posed by 17 problem areas including air pollution, water contamination, solid waste sites, pesticides and ecosystem degradation. The risks were calculated using five criteria: area affected, vulnerability of affected population, severity of impact, irreversibility of effect and uncertainty. To construct this matrix, both literature reviews and expert interviews in Cuba were conducted in 2000. The results showed a general decrease in risk scores during the Special Period. Before the Special Period, high risks were posed by: terrestrial degradation and industrial wastewater and sludge, followed by freshwater degradation, surface water stressors, and pesticides. After the Special Period, industrial wastewater and sludge and pesticides were no longer high-risk areas, but municipal wastewater and marine coastal degradation ranked higher than previously. Also, the risk endpoints most stressed after 1990 were affected by activities controlled by the government, such as mining and tourism, and lack of infrastructure. Therefore, the claims that public environmental education is the main pathway to sustainable development in Cuba seem uninformed and other management practices should be evaluated.
    Coastal waters, surface waters, and groundwater are impacted by wastewater and stormwater discharges, as well as agricultural flows containing animal waste and nutrients. A One Water approach posits that components of the water system... more
    Coastal waters, surface waters, and groundwater are impacted by wastewater and stormwater discharges, as well as agricultural flows containing animal waste and nutrients. A One Water approach posits that components of the water system have overlapping and interactive impacts on other aspects of the system, for which a comprehensive approach to water management is needed to further inform public health decisions. Current frameworks for monitoring wastewater effluent and recreational surface waters include the measurement of fecal indicator bacteria. Although viral pathogens are likely to be transported further and can survive longer than bacterial pathogens, virus monitoring is not required for recreational waters. A scientific consensus is emerging that the use of bacterial indicators alone does not account for nor represent the health risks associated with viral pathogens due to the differences in the fate and transport of bacterial versus viral pathogens in wastewater treatment, surface water, and groundwater. Furthermore, it is likely that the public health risk associated with these waterborne pathogens is variable and diverse. For example, under drought conditions, effluents of urban water systems can comprise most of the dry weather flow in downstream waters, which are often used as sources of drinking water. This de facto reuse could increase viral risk for the end users of this water. A One Water approach will aid in protecting the health of the public from waterborne pathogens, regardless of where those pathogens entered the water system. In this review, we assert that monitoring for fecal indicator viruses can complement the monitoring of bacterial indicators, thereby improving public health protections. Bacteriophages have the strongest research foundation and correlation with viral pathogens along with some prediction power for risk to human health. Methods for detecting and quantifying coliphages are briefly summarized, as are challenges in the implementation of testing. Key knowledge gaps and research priorities are discussed so that the potential value and limitations of coliphage monitoring can be better addressed and understood.
    To provide further clarification on the virus that causes COVID-19 infections, which is technically named SARSCoV-2, and concerns about how it relates to residuals, sludge, and biosolids for water resource recovery facilities (WRRFs) as... more
    To provide further clarification on the virus that causes COVID-19 infections, which is technically named SARSCoV-2, and concerns about how it relates to residuals, sludge, and biosolids for water resource recovery facilities (WRRFs) as well as the wastewater sector at large, this paper includes a review of available data related to the virus and surrogates as well as their potential associations with residuals, sludge, and biosolids. This update is intended to supplement to the currently published article, “The Water Professionals Guide to COVID-19” the Waterborne Infectious Disease Outbreak Control (WIDOC) working group of the Water Environment Federation (Maal-Bared et al., 2020).
    Preamble On February 19, 2020, WEF published The Water Professional’s Guide to COVID-19. The Guide was meant to increase water sector awareness of COVID-19 virus and any water and wastewater-related issues and relevant resources. The... more
    Preamble On February 19, 2020, WEF published The Water Professional’s Guide to COVID-19. The Guide was meant to increase water sector awareness of COVID-19 virus and any water and wastewater-related issues and relevant resources. The content was reprinted in the April 2020 issue of Water Environment & Technology. Since then, the World Health Organization (WHO) has declared COVID-19 a pandemic and the disease has spread to more than 210 countries with more research on the virus being published every day.
    Biological nutrient removal is highly reliant on maintaining a heterogeneous, balanced, and metabolically active microbial community that can adapt to the fluctuating composition of influent wastewater and encompassing environmental... more
    Biological nutrient removal is highly reliant on maintaining a heterogeneous, balanced, and metabolically active microbial community that can adapt to the fluctuating composition of influent wastewater and encompassing environmental conditions. Maintaining this balance can be challenging in municipal wastewater systems that sporadically receive wastewater from industrial facilities due to the impact of heavy metals and other contaminants on the microbial ecology of the activated sludge. A thorough understanding of the impacts of heavy metals on activated sludge and of practical monitoring options is needed to support decision-making at the wastewater utility level. This paper is divided into two parts. In the first part, the review explains what happens when heavy metals interact with activated sludge systems by highlighting biosorption and bioaccumulation processes, and when an activated sludge system switches from bioaccumulation to toxic shock. Here, it also summarizes the impact...
    Parasitic diseases are of considerable public health significance in Canada, particularly in rural and remote areas. Food- and waterborne parasites contribute significantly to the overall number of parasitic infections reported in Canada.... more
    Parasitic diseases are of considerable public health significance in Canada, particularly in rural and remote areas. Food- and waterborne parasites contribute significantly to the overall number of parasitic infections reported in Canada. While data on the incidence of some of these diseases are available, knowledge of the true burden of infection by the causative agents in Canadians is somewhat limited. A number of centers of expertise in Canada study various aspects of parasitology, but few formal societies or networks of parasitologists currently exist in Canada, and previously none focused specifically on food or environmental transmission. The recently established Food and Environmental Parasitology Network (FEPN) brings together Canadian researchers, regulators and public health officials with an active involvement in issues related to these increasingly important fields. The major objectives of the Network include identifying research gaps, facilitating discussion and collabo...
    Raw sewage ordinarily contains various biohazards (disease-causing organisms and their products), such as bacteria, viruses, fungi, helminths, and protozoa. Types, concentrations and survival of biohazards in sewage vary greatly depending... more
    Raw sewage ordinarily contains various biohazards (disease-causing organisms and their products), such as bacteria, viruses, fungi, helminths, and protozoa. Types, concentrations and survival of biohazards in sewage vary greatly depending on geographical and seasonal factors, and treatment levels within a wastewater treatment plant (WWTP). A review was undertaken to identify evidence of biohazard exposures and health symptom responses in WWTP workers who may be at increased occupational risk compared to the general population. Studies from 1990 onwards identified the following WWTP equipment or tasks as the most important for biohazard exposures: pre-treatment equipment (either indoors or in confined areas), sludge dewatering equipment, worker tasks involving water used for cleaning and contact with raw sewage. Twenty-eight epidemiological observational studies were identified that compared various markers
    Mounting evidence suggests that solids are a reliable matrix for SARS-CoV-2 detection in wastewater, yet studies comparing solids-based methods and common concentration methods using the liquid fraction remain limited. In this study, we... more
    Mounting evidence suggests that solids are a reliable matrix for SARS-CoV-2 detection in wastewater, yet studies comparing solids-based methods and common concentration methods using the liquid fraction remain limited. In this study, we developed and optimized a method for SARS-CoV-2 detection in wastewater using moderate-speed centrifuged solids and evaluated it against an ultrafiltration reference method. SARS-CoV-2 was quantified in samples from 12 wastewater treatment plants from Alberta, Canada, using RT-qPCR targeting the N2 and E genes. PCR inhibition was examined by spiking salmon DNA. The effects of using different amounts of solids, adjusting the sample pH to 9.6–10, and modifying the elution volume at the final step of RNA extraction were evaluated. SARS-CoV-2 detection rate in solids from 20 mL of wastewater showed no statistically significant difference compared to the ultrafiltration method (97/139 versus 90/139, p = 0.26, McNemar’s mid-p test). The optimized wastewate...

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