Well Living Lab

More information coming soon!

Publications:

Coming soon!


Surge Capacity Engineering Project

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In the event of a pandemic caused by an airborne illness or bioterror event, it is important that hospitals increase their isolation room capacity to house and treat a surge of infectious patients. To test a low-cost method of increasing surge capacity, we performed a demonstration of establishing a temporary negative-pressure isolation ward at a functioning hospital. Pressure sensors and ventilation flow rate data were used to evaluate the performance of the isolation ward. To seal the ward from the rest of the hospital, a temporary anteroom was built (pictured above) and installed. UV-C lamps were installed in stairwells adjacent to the ward to disinfect any escaping contamination that may leak into these unventilated spaces. Overall the demonstration was successful and we are currently providing guidance on ways to apply the lessons learned during the SCEP to other hospitals, with the goal of having hospitals in many metro areas evaluate and update their surge capacity plans using similar techniques.

Publications:

Miller, SL, Clements, N, Elliott, SA,  Subhash, SS, Eagan, A, Radonovich, LJ (2017). Implementing a negative-pressure isolation ward for a surge in airborne infectious patients. American Journal of infection Control 46(6), 652-659. LINK.

Clements, N, Miller, SL, Subhash, SS, Eagan, AE (2015). Hospital Surge Capacity: Practical Aspects of Temporary Isolation Ward Design. Healthy Buildings 2015 Conference Paper.

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Colorado Coarse Rural-Urban Sources and Health (CCRUSH) Study

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In 2006 when the US EPA revised their National Ambient Air Quality Standards, it was decided that PM10-2.5 would not be classified as a criteria pollutant due to insufficient evidence of a health impact. In response, EPA funded multiple projects to deepen the knowledge base of the sources and health impacts of PM10-2.5. The Colorado Coarse Rural-Urban Sources and Health, or CCRUSH, study was one such EPA-funded study. The goal of the CCRUSH study was to measure PM10-2.5 in urban Denver, CO and rural Greeley, CO for three years and conduct detailed aerosol characterization and an epidemiological study.

Three TEOM 1405-DF monitors operated on school rooftops in the two cities for three years, collecting hourly-average PM10-2.5 and PM2.5 mass concentration data. This data set was analyzed for spatiotemporal and meteorological trends, revealing the intricate relationship between dust concentrations, traffic levels, wind conditions, and moisture levels.

One year of filter sampling was also conducted using 50 LPM in-house built dichotomous filter samplers. Composition analyses included: EC/OC concentrations, element abundances, endotoxin content, microbiological community analysis (via DNA sequencing), and characterization of the dissolved organic fraction using UV-vis absorbance and fluorescence. Particulate sources were determined using elemental and microbiological data sets, and we found road and geogenic dust, vehicle wear, road salt, and leaf surfaces were important sources in both communities, while cow fecal matter, likely from nearby cattle feedlots, was a source of bacteria in rural Greeley.

Another important result of the CCRUSH study was a detailed analysis of the errors introduced by using various combinations of the TEOM instruments to estimate PM10-2.5 concentrations through subtraction of PM2.5 from PM10 measurements. PM10-2.5 mass concentrations estimated through subtraction using a mixture of TEOMs with and without semi-volatile loss correction resulted in biases of up to 30%. As the subtraction method is a common way of estimating PM10-2.5 for epidemiological studies, it is important that the exact configuration for each TEOM be considered and biases corrected to improve population exposure estimates.

Publications:

Clements, N, Milford, JB, Miller, SL, Peel, JL, Hannigan, MP (2016). Comparisons of Urban and Rural PM10-2.5 and PM2.5 Mass Concentrations and Semi-Volatile Fractions in Northeastern Colorado. Atmospheric Chemistry and Physics 16(11), 7469-7484. LINK.

Clements, N, Eav, J, Xie, M, Hannigan, MP, Miller, SL, Navidi, W, Peel, JL, Schauer, JJ, Shafer, MM, Milford, JB (2014). Concentrations and source insights for trace elements in fine and coarse particulate matter. Atmospheric Environment 89, 373-381. LINK.

Clements, N, Milford, JB, Miller, SL, Navidi, W, Peel, JL, Hannigan, MP (2013). Errors in coarse particulate matter (PM10-2.5) mass concentrations and spatiotemporal characteristics when using subtraction estimation methods. Journal of the Air & Waste Management Association 63, 1386-1398. LINK.

Robert, B, Clements, N, Emerson, J, Wiedinmyer, C, Hannigan, M, Fierer, N (2013). Seasonal variability in the bacterial and fungal diversity of the near-surface atmosphere. Environmental Science and Technology 47(21), 12097-12106. LINK.

Clements, N, Piedrahita, R, Ortega, J, Peel, JL, Hannigan, M, Miller, SL, Milford, JB (2012). Characterization and Nonparametric Regression of Rural and Urban Coarse Particulate Matter Mass Concentrations in Northeastern Colorado. Aerosol Science and Technology 46(1), 108-123. LINK.

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Sloan15 Study

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To understand the temporal variability of microbial communities in homes in Colorado, 15 homes were sampled 8 times throughout a year. Sampling included collecting microbiological samples as well as detailed home characteristics, inhabitant activity diaries, and indoor/outdoor air quality data. We are currently in the process of digging through this rich data set, so check back for results and publications!

During the data collection phase of the Sloan15 study, the Front Range Flood of 2013 happened to impact homes in the area of study. Petri dishes collected in basements of non-flooded and flooded homes (after remediation) were analyzed for bacteria and fungal abundances and community structure. This investigation showed remediation did not return flooded homes to their original state with regard to microbial communities, and fungal DNA increased in flooded homes compared to non-flooded homes. Improvements to remediation efforts can be guided by these findings.

Publications:

Emerson, JB, Keady, PB, Clements, N, Morgan, EE, Awerbuch, J, Miller, SL, Fierer, N (2016). High temporal variability in airborne bacterial diversity and abundance inside single‐family residencesIndoor Air 27(3), 576-586. LINK.

Emerson, JB, Keady, P, Brewer, T, Clements, N, Morgan, E, Awerbuch, J, Miller, SL, Fierer, N (2015). Impacts of flood damage on airborne bacteria and fungi in homes after the 2013 Colorado Front Range Flood. Environmental Science and Technology 49(5), 2675-2684.

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UV-C Disinfection

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Public transportation settings are ideal for spreading disease due to crowding and poor ventilation. In this project we designed a system to disinfect air in the breathing zone in such a setting. We focused the project around the idea of housing a UV-C lamp and small fan in the back of seats to disinfect recirculated air. Unfortunately, the mercury vapor lamp was the only commercially available UV-C lamp at the time, but installing many mercury vapor lamps in a public transportation setting is hazardous. Because of this design limitation, we tested the disinfection rates of two research grade lamp types (xenon excimer and LED) along with a standard mercury vapor lamp. We also tested a novel coating which changed the reflective properties of the walls of the lamp housing so they were diffuse instead of reflective, resulting in much higher UV-C flux within the housing. Chemical actinometry was used to measure UV-C fluence within the lamp housing, and results agreed well with a photon-trace model.

Publications:

Ryan, K, McCabe, K, Clements, N, Hernandez, M, Miller, SL (2010). Inactivation of Airborne Microorganisms Using Novel Ultraviolet Radiation Sources in Reflective Flow-Through Control Devices. Aerosol Science and Technology 44(7), 541-550.  LINK.

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