Shelly Miller Ph.D. – The Microbiome of Water Damaged Buildings & Healthy Buildings 2015

Air Date: 5-01-2015|Episode 366

This week on IAQ Radio we continue our focus on the theme “research to practice” with Shelly Miller, PhD. Dr. Miller is an Associate Professor at the University of Colorado Boulder in the Mechanical Engineering Department and faculty in the interdisciplinary undergraduate Environmental Engineering Program…

Full Description:

This week on IAQ Radio we continue our focus on the theme “research to practice” with Shelly Miller, PhD. Dr. Miller is an Associate Professor at the University of Colorado Boulder in the Mechanical Engineering Department and faculty in the interdisciplinary undergraduate Environmental Engineering Program.


Shelly Miller, Ph. D.

She is also the Conference Chair for the Healthy Buildings 2015 America Conference that will be held in Boulder, Colorado July 19-22, 2015. Healthy Buildings is a unique forum for built environment researchers and professionals to engage with innovative projects, products and services and to meet and collaborate with colleagues working on the pressing global challenge of making buildings healthy, energy efficient, and sustainable. At the University of Colorado Boulder Dr. Miller investigates indoor air quality, assesses exposures to air pollutants, and develops and evaluates air pollution control measures. Her current research projects include weatherization of homes and indoor air quality, understanding the role of ventilation systems in the transmission of infectious agents in buildings and intermodal transportation, engineering controls for reducing exposures to infectious diseases, studying ultraviolet germicidal coil cleaning technology, source apportionment of particulate matter and associated health effects, characterization of indoor air quality and the microbial communities in homes, and investigating urban air quality issues including industrial odor episodes. Dr. Miller has received funding for her research program from the US EPA, CDC, NIOSH, NSF, NIH, ASHRAE, HUD, Alfred P. Sloan Foundation, and various private foundations and industry sponsors. LEARN MORE about the mircobiome of water damaged buildings, Healthy Buildings 2015 and much more this week on IAQ Radio!microbione

Z-Man’s Blog:

The Microbiome of Water Damaged Buildings & Healthy Buildings 2015

Shelly Miller, PhD was today’s guest on IAQradio. Dr. Miller is an Associate Professor in the Department of Mechanical Engineering at the University of Colorado, Boulder. As a young kid Shelly was interested in math and the use of math to solve problems.

Gold NuggetsNuggets mined from today’s episode:

  • To get more women interested in engineering, she suggests exposing kids to engineering and other sciences at a younger age.
  • Has started a collaborative research project into the effects of weatherization on IAQ. The project is studying 250 homes, half of which are weatherized. The study will try and determine if occupants of weatherized homes have a higher incidence of respiratory problems. In one instance she found that a very tight weatherized home with radiant flooring had poor air exchange with the outdoors. High level of particulate related to cooking and cleaning were found. Occupants developed respiratory symptoms and asthma after moving into the home. Recommended improving ventilation with an ERV (energy recovery ventilation) to help clear air of contaminants. Occupant symptoms have subsided.
  • The Sloan foundation funded study of the microbiome of 15 Boulder, CO homes. Swab samples, air samples and vent filter samples were taken in subject homes twice per season over 1 year and the DNA of microbes was studied. QPCR (quantitative polymerase chain reaction) and DNA analysis tells scientists what microbes are present not whether or not the organisms are viable. Seasonal changes in the microbiome were not found, there was no way to predict variability. While lower in microbial diversity than swab samples, air and vent samples are useful for providing material and information.
  • Most bacteria in the microbiome come from people and pets. While most fungi originate outdoors.
  • The Sloan study took an interesting twist when 36 flooded and 14 non-flooded Boulder, CO homes remediated 60 days after the flood were added to the study. In the flood study, sterilized petri dishes were suspended 1-2 feet from ceilings for 2 months and then analyzed.
  • While health effects were not studied, following remediation (which included removal of wet carpet, and wet sheetrock) both professional and DIY the flooded homes had significantly different organisms and statistically higher (3X) levels of fungi than the -flooded. Studies of post Hurricane Katrina flooded houses in New Orleans that were remediated 3 months after the flood indicated only a slight decrease 2 years later.
  • With energy conservation in mind, she is a big fan of using ventilation in homes to reduce sources of contamination such as cooking and cleaning. She advocates having and using vent hoods even with electric stoves.
  • An advocate of using Ultraviolet Germicidal Irradiation (UVGI)in hospital isolation rooms/wards, in densely occupied spaces such as jails/prisons, homeless shelters, waiting rooms, etc. She recommends using UVGI in situations when ventilation cannot be increased and using UVGI in upper-room/air-ducts/cooling coils. Good air mixing is necessary when UVGI lights are suspended in rooms.
  • Electrically enhanced air filters do lower particulate in homes.
  • Cooking oils and cleaning products exacerbate air quality problems.
  • Homes of people with lower economic status often have poor IAQ related to overcrowding.
  • Wall-to-wall carpeting is a sink for shedded skin bacteria taxa, which can be re-suspended.
  • In a healthy microbiome higher diversity of microbes is probably a plus.
  • Her dream is to figure out how to widely implement residential ventilation systems that simultaneously improve IAQ and reduce energy consumption.
  • She invites all IAQradio listeners to attend the Healthy Buildings 2015 America Conference in Boulder, Colorado in July. For more info go to,

Z-Man thoughts:

1. More study of the microbiome of water damaged and flooded buildings before and after remediation will likely change our thinking on: industry standards, structural drying equipment/processes, the use of antimicrobials, etc. Even tight adherence to proscriptive industry standards may not result in the high quality outcomes we think we are achieving.

2. Dr. Miller seemed eager to gain more insight and field experience by working with restoration contractors in the Boulder, CO area.


Today’s Music: Bacteria (A Song) by Florence Schechter, YouTube.

Trivia Question:  What type of Ultraviolet Light is germicidal?

Z-Man signing off