Chang-Yu Wu

• PhD
• Professor and Department Chair at University of Miami

Pathogens can be collected from air and detected in samples by many methods. However, merely detecting pathogens does not answer whether they can spread disease. To fully assess health risks from exposure to airborne pathogens, the infectivity of those agents must be assessed. Air samplers which operate by growing particles through water vapor cond...

Rationale Stigma permeates disability experiences and compounds disability-related challenges. Objective Identify individual and environmental factors of stigmatizing experiences of college students with learning disabilities (LDs) and attention-deficit/hyperactivity disorder (ADHD). Methodology A qualitative descriptive design was used with a th...

OBJECTIVES/GOALS: Our goal is to determine whether microplastic fibers (MPFs) provide signals for dendritic cell-induced Th2 polarization via epithelial-cell-derived thymic stromal lymphopoietin (TSLP). We seek to highlight a potential mechanism for MPF-induced airway toxicity associated with asthma exacerbation. METHODS/STUDY POPULATION: Primary h...

As SARS-CoV-2 swept across the globe, increased ventilation and implementation of air cleaning were emphasized by the US CDC and WHO as important strategies to reduce the risk of inhalation exposure to the virus. To assess whether higher ventilation and air cleaning rates lead to lower exposure risk to SARS-CoV-2, 1274 manuscripts published between...

Current modeling practices for environmental and sociological modulated infectious diseases remain inadequate to forecast the risk of outbreak(s) in human populations, partly due to a lack of integration of disciplinary knowledge, limited availability of disease surveillance datasets, and overreliance on compartmental epidemiological modeling metho...

The ability to collect size-fractionated airborne particles that contain viable bacteria and fungi directly into liquid medium while also maintaining their viability is critical for assessing exposure risks. In this study, we present the BioCascade impactor, a novel device designed to collect airborne particles into liquid based on their aerodynami...

Indoor Air Quality (IAQ) in schools has received attention over the past decades but still lacks specific standards and regulations. This study aimed to review the impact of bioaerosol activity in indoor environments on acute respiratory diseases and explore whether carbon dioxide can be used as an indicator of bioaerosol and respiratory diseases i...

xD;Background The occurrence of cases of COVID-19 suggests that it will likely become seasonally endemic in human populations. Objectives We seek to provide a quantification of the seasonality of the occurrence and severity of COVID-19 cases in human populations. Methods Using global data, we show that the spatiotemporal distribution of COVID-19 c...

Airborne transmission of infectious (viable) SARS-CoV-2 is increasingly accepted as the primary manner by which the virus is spread from person to person. Risk of exposure to airborne virus is higher in enclosed and poorly ventilated spaces. We present a study focused on air sampling within residences occupied by individuals with COVID-19. Air samp...

CeO2 and CuO nanoparticles (NPs) are used as additives in petrodiesel to enhance engine performance leading to reduced diesel combustion emissions. Despite their benefits, the additive application poses human health concerns by releasing inhalable NPs into the ambient air. In this study, a bioinspired lung cell exposure system, Dosimetric Aerosol i...

Real-time monitoring of dosimetry is critical to mitigating the constraints of offline measurements. To address this need, the use of the Scanning Mobility Particle Sizer (SMPS) to estimate the dose delivered through the Dosimetric Aerosol in Vitro Inhalation Device (DAVID) was assessed. CuO nanoparticles suspended in ethanol at different concentra...

This study aimed to provide environmental surveillance data for evaluating the risk of acquiring SARS-CoV-2 in public areas with high foot traffic in a university. Air and surface samples were collected at a university that had the second highest number of COVID-19 cases among public higher education institutions in the U.S. during Fall 2020. A tot...

OBJECTIVES/GOALS: In vitro models that mimic the human respiratory system are needed to assess the toxicity of inhaled contaminants. Therefore, our goal is to establish a Dosimetric Aerosol in-Vitro Inhalation Device (DAVID) that delivers aerosols in different patterns to human lung cells cultured at an air-liquid interface (ALI). METHODS/STUDY POP...

Aromatic and aliphatic hydrocarbons (AAHs) are comprised of a variety of gaseous chemicals that may affect human and environmental health. To remove AAHs from air, polytetrafuoroethylene-nickel oxide (PTFE-NiO) composite nanofiber fllter mats (NFMs) were synthesized and characterized for their ability to effectively adsorb AAHs. The NiO-nanoparticl...

We report a point-of-care (POC) device for simultaneous detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza A viruses. The device carries out sample preparation using ball-based valves for sequential delivery of reagents. A microfluidic paper-based analytical device (μPAD) in the detection unit enables RNA isolat...

While a network of low-cost sensors (LCS) boosts the capability in monitoring of air quality as covering a wide area, its fixed positioning hinders pinpointing of an unknown emitting source, its accuracy is variable over time, and its operation requires more periodic calibration than the USEPA's reference monitors. Alternatively, for short-term con...

Pathways of transmission of coronavirus (COVID-19) disease in the human population are still emerging. However, empirical observations suggest that dense human settlements are the most adversely impacted, corroborating a broad consensus that human-to-human transmission is a key mechanism for the rapid spread of this disease. Here, using logistic re...

The B.1.617.2 (Delta) variant of SARS-CoV-2 emerged in India in October of 2020 and spread widely to over 145 countries, comprising over 99% of genome sequence-confirmed virus in COVID-19 cases of the United States (US) by September 2021. The rise in COVID-19 cases due to the Delta variant coincided with a return to in-person school attendance, str...

Pathways of transmission of coronavirus (COVID-19) disease in the human population are still emerging. However, empirical observations suggest that dense human settlements are the most adversely impacted, corroborating a broad consensus that human-to-human transmission is a key mechanism for the rapid spread of this disease. Here, using logistic re...

The complexity of transmission of COVID-19 in the human population cannot be overstated. Although major transmission routes of COVID-19 remain as human-to-human interactions, understanding the possible role of climatic and weather processes in accelerating such interactions is still a challenge. The majority of studies on the transmission of this d...

Since mask use and physical distancing are difficult to maintain when people dine indoors, restaurants are perceived as high risk for acquiring COVID-19. The air and environmental surfaces in two restaurants in a mid-scale city located in north central Florida that followed the Centers for Disease Control and Prevention (CDC) reopening guidance wer...

Our career-forward approach to general chemistry laboratory for engineers involves the use of design challenges (DCs), an innovation that employs authentic professional context and practice to transform traditional tasks into developmentally appropriate career experiences. These challenges are scaled-down engineering problems related to the US Nati...

Early and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and influenza viruses at the point-of-care is crucial for reducing disease transmission during the current pandemic and future flu seasons. To prepare for potential cocirculation of these two viruses, we report a valve-enabled, paper-based sample preparatio...

Fitness centers are considered high risk for SARS-CoV-2 transmission due to their high human occupancy and the type of activity taking place in them, especially when individuals pre-symptomatic or asymptomatic for COVID-19 exercise in the facilities. In this study, air (N=21) and surface (N=8) samples were collected at a fitness center through five...

Early and accurate detection of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) at the point-of-care (POC) is crucial for reducing the transmission of coronavirus disease 2019 (COVID-19). To address this need, we have developed a valve-enabled lysis, paper-based RNA enrichment, and RNA amplification device (VLEAD) for detecting SARS-Co...

Individuals with COVID-19 are advised to self-isolate at their residences unless they require hospitalization. Persons sharing a dwelling with someone who has COVID-19 have a substantial risk of being exposed to the virus. However, environmental monitoring for the detection of virus in such settings is limited. We present a pilot study on environme...

Aerosol transmission is one of the three major transmission routes of respiratory viruses. However, the dynamics and significance of the aerosol transmission route are not well understood, partially due to the lack of rapid and efficient tools for on-the-spot detection of airborne viruses. We report a hand-held device that integrates a 3D-printed s...

Objectives: Because detection of SARS-CoV-2 RNA in aerosols but failure to isolate viable (infectious) virus are commonly reported, there is substantial controversy whether SARS-CoV-2 can be transmitted through aerosols. This conundrum occurs because common air samplers can inactivate virions through their harsh collection processes. We sought to...

Background - There currently is substantial controversy about the role played by SARS-CoV-2 in aerosols in disease transmission, due in part to detections of viral RNA but failures to isolate viable virus from clinically generated aerosols. Methods - Air samples were collected in the room of two COVID-19 patients, one of whom had an active respirat...

A pilot project was conducted to determine the effect of common construction dusts as interferences in a new portable end-of-shift (EoS), direct-on-filter (DoF) sampling and analysis method for respirable crystalline silica (RCS), in this case, quartz. Construction dusts were prepared from plaster, drywall, cement and brick by grinding, aerosolizin...

The progression of COVID-19 worldwide can be tracked by identifying mutations within the genomic sequence of SARS-CoV-2 that occur as a function of time. Such efforts currently rely on sequencing the genome of SARS-CoV-2 in patient specimens (direct sequencing) or of virus isolated from patient specimens in cell cultures. A pilot SARS-CoV-2 air sam...

The progression of COVID-19 worldwide can be tracked by identifying mutations within the genomic sequence of SARS-CoV-2 that occur as a function of time. Such efforts currently rely on sequencing the genome of SARS-CoV-2 in patient specimens (direct sequencing) or of virus isolated from patient specimens in cell cultures. A pilot SARS-CoV-2 air sam...

A first-of-its-kind aerosol exposure device for toxicity testing, referred to as the Dosimetric Aerosol in Vitro Inhalation Device (DAVID), was evaluated for its ability to deliver airborne nanoparticles to lung cells grown as air-liquid interface (ALI) cultures. For inhalation studies, ALI lung cell cultures exposed to airborne nanoparticles have...

Date Presented 04/06/19 Self-efficacy (SE) is critical to the success of students with learning and attention disorders (L/AD). Research describes processes for development of SE in undergraduates for identifying and obtaining the information, resources, and skills needed to bolster college-role success. Fifty-two undergraduates with L/AD engaged i...

Date Presented 04/06/19 Mixed-method analysis of advocacy projects were created by college students with learning and attention disorders (L/AD). Articulated textual messaging of disability informed a theoretical model of identity development for young adults of L/AD and were used to test for changes over time. Statistically significant results ind...

Impregnated filters treated with alkali and humectant were first used as collection media to assess occupational exposure to sulfur dioxide (SO2), as outlined in the National Institute for Occupational Safety and Health Method 6004 in 1979. Since then, updated treatment protocols have been proposed with decreased amounts of alkali and glycerol, whi...

The electrodynamic screen (EDS), which transports particles by electrodynamic waves, is a promising technology to repel deposited dust from solar devices in places where water resources are scarce. As gravitational force may impede dust removal on concave or parabolic solar concentrators, this study aimed to determine the feasibility of the EDS to...

Existing bioaerosol sampling systems are designed for bacterial aerosol collection/detection based on inertia principles. They are very ineffective for viral aerosols because viruses are much smaller than bacteria and are not effectively captured by the equipment. In addition to being ineffective, conventional detection methods for viruses are time...

Viruses that affect humans, animals, and plants are often dispersed and transmitted through airborne routes of infection. Due to current technological deficiencies, accurate determination of the presence of airborne viruses is challenging. This shortcoming limits our ability to evaluate the actual threat arising from inhalation or other relevant co...

Performance loss due to dust accumulation on solar energy collection surfaces has garnered increasing research interest in recent years. The electrodynamic dust shield (EDS) has been proposed to clean solar devices, the design of which can benefit from understanding of the microscopic interactions of individual dust particles with each other and th...

Inhalation of aerosols containing pathogenic viruses can result in morbidity, in some cases leading to mortality. The objective of this study was to develop a model for assessing how infectious viruses might distribute in airborne particles using bacteriophage MS2 as a surrogate for human viruses. Particle deposition in the respiratory system is si...

To overcome limitations of existing air-cleaning filters in capturing and deactivating aerosolized microorganisms, this study was embarked to evaluate novel Ag, Zn, and Fe nanoparticle-doped cotton filters (AgCt, ZnCt, FeCt), as biocidal filters for bioaerosol attenuation. To evaluate the biocidal activity of the nanocomposite filters, the survival...

Electrodynamic dust shield (EDS) uses traveling-wave or standing-wave electrodynamic effects to repel dust particles from a surface, and has been proposed as a potential anti-dust solution for mitigating soiling loss in solar energy applications. In this study, a standing-wave EDS technique was tested in a cyclic manner at field-relevant dust loadi...

One limitation in air sampling of airborne microorganisms is their inactivation by forceful impaction and/or dehydration during the collection process. Proper inhalation risk assessments require proof of viability, as non-viable microorganisms cannot cause infectious diseases. In this study, laboratory-generated aerosols of a vegetative bacterium (...

Learning disabilities are highly prevalent on college campuses, yet students with learning disabilities graduate at lower rates than those without disabilities. Academic and psychosocial supports are essential for overcoming challenges and for improving postsecondary educational opportunities for students with learning disabilities. A holistic, mul...

Protection of public health against pathogenic viruses transmitted through the airborne route requires effective sampling of airborne viruses for determination of their concentration and distribution. However, sampling viable airborne viruses is challenging as conventional bioaerosol sampling devices operate on inertia-based mechanisms that inheren...

Exploring affordable and reliable filters to sample sulfuric acid mists is of interest because the polytetrafluoroethylene filters recommended by NIOSH Method 7908 are relatively costly. In this study, the feasibility of hardened cellulose filters such as Whatman grade 540, 541, and 542 filters were investigated for sampling sulfuric acid mists. Th...

The dynamics and significance of aerosol transmission of respiratory viruses are still controversial, for the major reasons that virus aerosols are inefficiently collected by commonly used air samplers and that the collected viruses are inactivated by the collection method. Without knowledge of virus viability, infection risk analyses lack accuracy...

A largely neglected aspect necessary to prevent energy losses of photovoltaic (PV) panels is efficient and cost-effective mitigation of dust soiling. A potential solution is an electrodynamic dust shield (EDS) to lift and transport dust off the PV panel via electrodynamic waves generated by electrodes on the panel surface. Accordingly, the objectiv...

A novel personal sampler was designed to measure inorganic acid mists and gases for determining human exposure levels to these acids in workplaces. This sampler consists of (1) a parallel impactor for classifying aerosol by size following the ISO/CEN/ACGIH defined human thoracic fraction, (2) a cellulose filter to collect the residual acid mist but...

A viable virus aerosol sampler (VIVAS) effectively collected viable influenza A and B viruses from air inside a student health care center during an influenza outbreak. The viruses had “drifted” genes, showcasing the usefulness of the VIVAS for air sampling and noninvasive surveillance of viruses in circulation.

Bats are natural reservoirs of coronaviruses and other viruses with zoonotic potential. Florida has indigenous non-migratory populations of Brazilian free-tailed bats ( Tadarida brasiliensis) that mostly roost in colonies in artificial structures. Unlike their counterparts in Brazil and Mexico, the viruses harbored by the Florida bats have been und...

In an effort to reduce nitrogen oxide (NOX) emission, many coal-fired electric utilities employ NOx control devices that utilize ammonia injection; this process, although successful at reducing NOx, results in a fly ash with elevated concentrations of ammonia. The reuse of ammoniated fly ash (AFA) raises environmental concerns due to the potential...

Converting optical diameter measured by an optical particle counter (OPC) to aerodynamic diameter measured by an aerodynamic particle sizer (APS) is of interest because the OPC is more affordable and portable. In this study, optical diameter was compared with volume equivalent diameter derived from aerodynamic diameter using monodisperse oleic acid...

Substantial time and money have been directed toward photovoltaic solar power. However, mitigation of dust on solar panels has been largely neglected. The objective of this research was to determine the performance and power consumption of an electrodynamic dust shield (EDS) to clean solar panels as a function of dust particle size. We utilized a d...

Rice husk, a common agricultural waste and renewable biomass, was pyrolyzed and then impregnated with NH4Cl and NH4Br to develop an efficient sorbent for gaseous mercury removal from flue gas. The sorbents’ performance was first investigated in a fixed-bed system with N2 atmosphere at 150 °C and then in an entrained-flow system with real coal-fired...

The spread of virus-induced infectious diseases through airborne routes of transmission is a global concern for economic and medical reasons. To study virus transmission, it is essential to have an effective aerosol collector such as the growth tube collector (GTC) system that utilizes water-based condensation for collecting virus-containing aeroso...

2016 American Association for Aerosol Research

The chemical characteristics of airborne particulate matter (PM) have been extensively studied; however, little information exists for its biological components (bioaerosol) especially during a haze event in mega cities. Herein, we studied the bioaerosol (fluorescent particle) dynamics on both haze and sunny days in Beijing from Dec. 2013 to March...

Aims: State-of-the-art bioaerosol samplers have poor collection efficiencies for ultrafine virus aerosols. This work evaluated the performance of a novel Growth Tube Collector (GTC), which utilizes laminar-flow water-based condensation to facilitate particle growth, for the collection of airborne MS2 viruses. Methods and results: Fine aerosols (...

Implications: Source apportionment of atmospheric polycyclic hydrocarbons (PAHs) in Palm Beach County, Florida, meant to estimate contributions of major sources in PAH concentrations measured at Belle Glade City of Palm Beach County. Number of benzene rings was found to be the key parameter in determining the source with the prevailing contributio...

Past studies have shown that many alumino-silicate mineral sorbents are effective in controlling heavy metal emission during incineration. The objective of this study was to identify Al-Si based mineral sorbents that can minimize leaching of heavy metals from the incinerator ash of Chromated Copper Arsenate (CCA-) treated wood. Experiments were car...

Chromated copper arsenate (CCA) was the dominant wood preservative used for outdoor wood products to prevent structural decay prior to its phase down starting from 2004. Incineration is one key disposal alternative for CCA-treated wood; however, it results in volatilization of metals at high temperature and accumulation of metals in ash. The object...

There is an increasing interest in understanding ambient bioaerosols due to their roles both in health and in climate. Here, we deployed an Ultraviolet Aerodynamic Particle Sizer to monitor viable (fluorescent) bioaerosol concentration levels at city centers (highly polluted) and their corresponding suburbs (near pristine) (total 40 locations) in 1...

A sol-gel synthesized Cu-promoted CeO2-TiO2 (CuCeTi) catalyst was used in the low temperature selective catalytic reduction (SCR) of nitrogen monoxide (NO) with ammonia (NH3). The combination of copper oxide (CuO) and cerium oxide (CeO2) improved SCR performance at low temperatures by increasing the dispersion of active species and the volume of su...

Date Presented 4/17/2015 Principles of community-engaged research are used to discover and address personal- and environmental-level concerns of university students with learning disabilities for the purpose of facilitating individual action and targeting institutional changes most important to participants.

Dust resuspension and deposition is a ubiquitous phenomenon in all lunar and Martian missions. The near-term plans to return to the Moon as a stepping stone to further exploration of Mars and beyond bring scientists’ attention to development and evaluation of lunar and Martian dust mitigation technologies. In this paper, different lunar and Martian...

Engineering education cannot expect to meet the demands of a global, diverse, knowledge-society without addressing a well-established issue of student recruitment and retention. The dropout rate for engineering students is around 40% as shown in various studies of a national scope. This retention issue is particularly prevalent for freshman student...

CuO-CeO2/TiO2 (CuCeTi) catalyst synthesized by a sol-gel method was employed to investigate mercury conversion under selective catalytic reduction (SCR) atmosphere (NO, NH3 plus O2). Neither NO nor NH3 individually exhibited an inhibitive effect on elemental mercury (Hg0) conversion in the presence of O2. However, Hg0 conversion over the CuCeTi cat...

There is an urgent need for simple, inexpensive, noninvasive, and repeatable technique for the diagnosis of pulmonary diseases. Bronchoalveolar lavage, which is the gold standard diagnostic method for pulmonary diseases, does not meet any of these criteria. This study seeks to develop and optimize a novel technique of Internal Airway Percussion (IA...

The production of Portland cement (PC) can result in the release of trace amounts of mercury (Hg) in stack emissions. As a means of controlling Hg stack emissions at Portland cement kiln operations, some facilities have instituted a process known as dust shuttling, where baghouse filter dust (BFD), a partially calcined byproduct, is collected and b...

The fate of mercury (Hg) in cement processing and products has drawn intense attention due to its contribution to the ambient emission inventory. Feeding Hg-loaded coal fly ash to the cement kiln introduces additional Hg into the kiln’s baghouse filter dust (BFD), and the practice of replacing 5% of cement with the Hg-loaded BFD by cement plants ha...

The modes of person-to-person transmission of influenza viruses, particularly the contribution of airborne transmission via inhalation of fine (,5 microns) particles are highly debated. Furthermore, airborne influenza virus particles collected from patients in recent studies used methods that, unfortunately, cannot discriminate between viable (infe...

To characterize the release of ammonia (NH3) from ammoniated fly ash in concrete, laboratory experiments were carried out with concrete added with fly ash containing ammonium loading ranging from 65 to 3,200 mg NH4 +/kg fly ash. A physical description of the NH3 release from concrete was given, and a quantitative diffusion model was developed. In t...

The concentrations and distribution of hazardous air pollutants (HAPs) metals emitted from four phosphate fertilizer plants in Central Florida, as well as their environmental and health impacts, were investigated. It was hypothesized that the modern control devices employed in the plants would lower the exposure, if any, to an acceptable level. The...