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Publications (68)
If lettuce is contaminated in the field, Shiga toxin-producing E. coli (STEC) O157:H7 can survive through the distribution chain. Prolonged cold storage during transportation may impact pathogen physiology, affecting subsequent stress survival and virulence. Greenhouse-grown Romaine lettuce, inoculated with three STEC O157:H7 strains, was harvested...
Listeria monocytogenes is a foodborne pathogen of concern for cancer patients, who face higher morbidity and mortality rates than the general population. The neutropenic diet (ND), which excludes fresh produce, is often utilized to mitigate this risk; however, an analysis weighing the theoretical listeriosis risk reduction of produce exclusion aspe...
Recent advancements in modeling suggest that microbial inactivation in leafy greens follows a nonlinear pattern, rather than the simple first‐order kinetics. In this study, we evaluated 17 inactivation models commonly used to describe microbial decline and established the conditions that govern microbial survival on leafy greens. Through a systemat...
The accuracy of predictive microbial models used in quantitative microbial risk assessment (QMRA) relies on the relevancy of conditions influencing growth or inactivation. The continued use of log‐linear models in studies remains widespread, despite evidence that they fail to accurately account for biphasic kinetics or include parameters to account...
Quantitative microbial risk assessment (QMRA) is a growing interdisciplinary field addressing exposures to microbial pathogens and infectious disease processes. Risk science is inherently interdisciplinary, but few of the contributing disciplinary programs offer courses and training specifically in QMRA. To develop multidisciplinary training in QMR...
The coronavirus disease 2019 pandemic highlighted the need for more rapid and routine application of modeling approaches such as quantitative microbial risk assessment (QMRA) for protecting public health. QMRA is a transdisciplinary science dedicated to understanding, predicting, and mitigating infectious disease risks. To better equip QMRA researc...
Guanabara Bay has been known to be polluted with trash and sewage from the surrounding areas, but health risks from recreational contact with water in the basin have not been well characterized. In this paper, fecal indicator bacteria (FIB) monitoring data are used to predict risks in three different exposure scenarios: (1) bathing in freshwater ri...
The residence time of water in residential building water systems is a critical factor regarding water quality at end use. Published literature has highlighted the importance of water age in these systems and its relationship with pathogenic bacteria such as Legionella pneumophila . However, tools to measure water age in such plumbing systems are t...
Elizabethkingia spp. are common environmental pathogens responsible for infections in more vulnerable populations. Although the exposure routes of concern are not well understood, some hospital‐associated outbreaks have indicated possible waterborne transmission. In order to facilitate quantitative microbial risk assessment (QMRA) for Elizabethking...
Understanding the end-use of water is essential to a plethora of critical research in premise plumbing. However, direct access to end-use data through physical sensors is prohibitively expensive for most researchers, building owners, operators, and practitioners. Therefore, machine learning models can alleviate these costs by predicting downstream...
Significant seasonal changes in chemical and microbiological water quality can occur in buildings at different fixture locations due to temperature and time dependent reaction rates. Here, a series of calibrated plumbing hydraulic‐water quality models were developed for the extensively monitored Retrofitted Net‐zero Energy, Water & Waste (ReNEWW) h...
Opportunistic pathogens, such as several species of Legionella, are a growing concern globally. This is especially true in building plumbing. Plumbing design guidance has not been updated to reflect changes in use, leading to increased hydraulic retention time and exacerbating pathogen risks. While the effects of several water quality variables on...
Eradication of poliovirus (PV) is a global public health priority, and as clinical cases decrease, the role of environmental surveillance becomes more important. Persistence of PV and the environmental factors that influence it (such as temperature and sample type) are an important part of understanding and interpreting positive environmental surve...
Biphasic decay has been observed for indicators and pathogens in bench-scale and in-situ water experiments for decades, however, first-order decay kinetics continue to be applied to persistence data because of their simplicity and ease of application. Model uncertainty introduced by broadly applying first-order decay kinetics to persistence data ma...
The environmental implications of antimicrobial resistance arising from food animal farm practice is still a knowledge gap. This study investigates the fate and transport of antimicrobial resistance genes related to the use of antibiotics on a dairy farm in Michigan. Manure, soil, animal feed, animal drinking water, surface and groundwater samples...
This study developed dose response models for determining the probability of eye or central nervous system infections from previously conducted studies using different strains of Acanthamoeba spp. The data were a result of animal experiments using mice and rats exposed corneally and intranasally to the pathogens. The corneal inoculations of Acantha...
Handwashing with soap is an effective and economical means to reduce the likelihood of Escherichia coli infection from indirect contact with contaminated surfaces during food preparation. The purpose of this study was to conduct a quantitative microbial risk assessment (QMRA) to evaluate the risk of infection from indirect contact with fomites cont...
The rising trend in water conservation awareness has given rise to the use of water-efficient appliances and fixtures for residential potable water systems. This study characterizes the microbial dynamics at a water-efficient residential building over the course of one year (58 sampling events) and examines the effects of water stagnation, season,...
When rainwater harvesting is utilized as an alternative water resource in buildings, a combination of municipal water and rainwater is typically required to meet water demands. Altering source water chemistry can disrupt pipe scale and biofilm and negatively impact water quality at the distribution level. Still, it is unknown if similar reactions o...
This study develops dose–response models for Ebolavirus using previously published data sets from the open literature. Two such articles were identified in which three different species of nonhuman primates were challenged by aerosolized Ebolavirus in order to study pathology and clinical disease progression. Dose groups were combined and pooled ac...
Sustainability, water conservation, water efficiency, and green infrastructure have led to significant decreases in the quantity of water used in buildings. In addition, changes in water usage, building design, plumbing material selection, and high‐efficiency fixtures contribute to water age and potential chemical and microbiological contamination....
This study develops a dose response model for Pseudomonas aeruginosa for the inhalation route of exposure using pre-existing data. P. aeruginosa is an opportunistic pathogen capable of causing community and hospital-acquired lung infections. As such, a dose response model for this route of exposure is needed to assess risks posed by the inhalation...
Several factors can affect virus behavior and persistence in water sources. Historically linear models have been used to describe persistence over time; however, these models do not consider all of the factors that can affect inactivation kinetics or the observed patterns of decay. Meanwhile, applying the appropriate persistence model is critical f...
Drinking water chemical quality can deteriorate after water enters building plumbing. This study aimed to better understand seasonal and spatial water quality differences in a highly monitored net-zero energy residential building. Water flow rate and temperature were monitored for one year at the service line and at every fixture throughout the cro...
Middle Eastern respiratory syndrome, an emerging viral infection with a global case fatality rate of 35.5%, caused major outbreaks first in 2012 and 2015, though new cases are continuously reported around the world. Transmission is believed to mainly occur in healthcare settings through aerosolized particles. This study uses Quantitative Microbial...
This study develops novel dose-response models for Naegleria fowleri from selected peer-reviewed experiments on the virulence based on the intranasal exposure pathway. One data set measured the response of mice intranasally inoculated with the amebae and the other study addressed the response of mice swimming in N. fowleri infected water. The measu...
Here, we summarize a symposium entitled “Microbiology of the Built Environment: Implications for Health and Design” that was presented at the National Council for Science and the Environment (NCSE) 17th National Conference and Global Forum in January 2017. We covered topics including indoor microbial exposures and childhood asthma, the influence of...
Bacillus spores resist inactivation, but the extent of their persistence on common surfaces is unclear. This work addresses knowledge gaps regarding biothreat agents in the environment to reduce uncertainty in risk assessment models. Studies were conducted to investigate the long‐term inactivation of Bacillus anthracis and three commonly used surro...
Appendix S1. Persistence Model Programming Code.
Table S1. Log reductions measured per species and fomite over time (days).
The use of aquaculture is increasing to meet the growing global demand for seafood. However, the use of aquaculture for seafood production incurs potential human health risks, especially from enteric bacteria such as Salmonella spp. Salmonella spp. was the most frequently reported cause of outbreaks associated with crustaceans from 1998 to 2004. Am...
Antimicrobial spray products are used by millions of people around the world for cleaning and disinfection of commonly touched surfaces. Influenza A is a pathogen of major concern, leading to up to 49,000 deaths and 114,000 hospitalizations per year in the United States alone. One of the recognized routes of transmission for influenza A is by trans...
Residential plumbing is critical for the health and safety of populations worldwide. A case study was conducted to understand fixture water use, drinking water quality and their possible link, in a newly plumbed residential green building. Water use and water quality were monitored at four in-building locations from September 2015 through December...
The United States (U.S.) environmental regulatory system relies heavily on self-reports to assess compliance among regulated facilities. However, the regulatory agencies have expressed concerns regarding the potential for fraud in self-reports and suggested that the likelihood of detection in the federal and state enforcement processes is low. In t...
Understanding the bacterial growth and decay kinetics on skin tissue is very important for controlling skin infection. Models are essential tools in understanding and predicting bacterial kinetics. One of the challenges in modeling bacterial kinetics is the estimation of model parameters, which can be addressed using an inverse problem approach. Th...
Microbial dose response modelling is vital to a well-characterized microbial risk estimate. Dose response modelling is an inherently multidisciplinary field, which collates knowledge and data from disparate scientific fields. This multidisciplinary nature presents a key challenge to the expansion of microbial dose response modelling into new groups...
Aims:
The goal of this study was to explore various models for describing viral persistence (infectivity) on fomites and identify the best fit models.
Methods and results:
The persistence of poliovirus over time was studied on three different fomite materials: steel, cotton, and plastic. Known concentrations of poliovirus type 1 were applied to...
Several major environmental programmes require regulated entities to measure and self-report pollutant levels to state regulatory agencies. This data is used to assess compliance, but critics suggest that it could be used more effectively to detect fraud in self-reports, a criminal offense. Efforts to develop and implement fraud detection tools are...
Addressing the persistence of bacterial indicators using qPCR and their respective DNA targets under various conditions is a critical part of risk assessment for water quality monitoring. The goal of this study was to examine the persistence of fecal indicator bacteria (FIB) via Escherichia coli uidA, enterococci 23S rDNA and Bacteroides thetataiot...
The U.S. Environmental Protection Agency (EPA) established the program known as ToxCast to develop ways to predict potential toxicity of chemicals and to develop a cost effective approach for prioritizing the thousands of chemicals that require toxicity testing. ToxCast uses advanced science tools to help to understand how normal human body process...
Case Study Data.
(XLSX)
The manufacture of novel synthetic chemicals has increased in volume and variety, but often the environmental and health risks are not fully understood in terms of toxicity and, in particular, exposure. While efforts to assess risks have generally been effective when sufficient data are available, the hazard and exposure data necessary to assess ri...
EPA Research Pathfinder Innovation Projects (PIPs), an internal competition for Agency scientists, was launched in 2010 to solicit innovative research proposals that would help the Agency to advance science for sustainability. In 2011, of the 117 proposals received from almost 300 scientists, 12 winners were awarded with seed funding to pursue thei...
The U.S. EPA must characterize potential risks to human health and the environment associated with manufacture and use of thousands of chemicals. High-throughput screening (HTS) for biological activity allows the ToxCast™ research program to prioritize chemical inventories for potential hazard. Similar capabilities for estimating exposure potential...
The U.S. EPA must consider thousands of chemicals when allocating resources to assess risk in human populations and the environment. High-throughput screening assays to characterize biological activity in vitro are being implemented in the ToxCastTM program to rapidly characterize potential hazard for hundreds of chemicals. However, without similar...
To develop a predictive dose-response model for describing the survival of animals exposed to Bacillus anthracis to support risk management options.
Dose-response curves were generated from a large dose-mortality data set (>11,000 data points) consisting of guinea pigs exposed via the inhalation route to 76 different product preparations of B. anth...
New efforts to manage chemical risks call for high-throughput hazard information to be interpreted in the context of screening level exposure information. Unfortunately, the exposure scenarios associated with many chemical products are not well characterized by simple approaches to exposure assessment. Therefore, the task of prioritizing tens of th...
Two of EPA’s current systems were evaluated for prioritization of the Challenge chemicals—E-FAST2 and SHEDS. The Exposure and Fate Assessment Screening Tool, Version 2.0 (E-FAST2) model is a screening-level tool that provides reasonable, yet conservative, exposure estimates for humans and ecological receptors from a variety of environmental media....
In the wake of the 2001 terrorist attacks, the use of Bacillus anthracis (anthrax) in bioterrorism attacks has emerged as a realistic concern. Thus, a contingency plan is needed to inform decision-makers about which response actions are appropriate and justified under which circumstances. This study considers the decisions: (1) to undertake prophyl...
As the United States tries to remain technologically competitive with other nations the demand for engineering professionals is expected to increase. Since the early 1990's, many K-12 engineering outreach programs have been incorporated into middle schools either through high tech electives or in tandem with the State prescribed math and science cu...
In the absence of quantitative risk-based information, responses to pathogenic agents in the environment, especially bioterrorism agents, can be guided by unrealistically low levels of risk tolerance (i.e. 0), as seen after the 2001 anthrax mail attacks. A novel and abbreviated risk framework links a series of three analytical models to inform a re...
Polypropylene fibers present favorable physical, hydraulic and specific surface area properties for use as a raw material or substrate in developing a novel iron-oxide-coated medium for the adsorption of heavy metals from drinking water. However, polypropylene fibers have not been explored for their ability to retain iron oxide coating under realis...
Iron oxide-coated sand has been demonstrated to be an effective adsorbent material for the removal of arsenic and other metals and metalloids from drinking water and wastewater. In this study, fibrous materials were evaluated for their ability to offer a high specific surface area alternative to sand as the substrate for the iron oxide coating. Fou...
In this study, a Bayesian statistical approach to fitting dose response parame- ters for Bacillus anthracis was compared to a classical, or frequentist, likelihood- based approach. The Bayesian approach uses a fully probabilistic framework to characterize parameter uncertainty. Parameters describing the susceptibility of individual species are mode...
Fibers present favorable physical, hydraulic and specific surface area properties for use as a substrate in developing a novel media for the adsorption of heavy metals from drinking water. Specifically the high surface area of the fibers is able to achieve a significantly higher iron-oxide density than reported results for sand under similar coatin...
High surface area polypropylene fibers were coated with iron-oxide. In column studies, iron-oxide coated polypropylene geosynthetic fibers were tested under hydraulic flow conditions to evaluate the ability of the fibers to retain the coating. Experiments were also conducted to determine its ability to be regenerated physically. The polypropylene m...
