Episode 652: Ed Light, CSP, CIH - Practice to Research: IEQ Lessons from the Real World

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Episode 652: Ed Light, CSP, CIH - Practice to Research: IEQ Lessons from the Real World

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Show Resources: Show Discussion:

11:58:20 From Victor Cafaro : Good show everyone
12:05:29 From John Cala : $0
12:05:33 From Neil Zimmerman : $1
12:05:43 From cliff zlotnik : sorry incorrect
12:33:32 From cliff zlotnik : trivia- In the 1972 movie Deliverance, actor Billy Redden played the inbred hillbilly banjo player. How much money was he paid for his performance?
12:34:16 From Ralph Froehlich : VeriDART sampling can show reduction in airborne concentrations of surrogate viruses, but little data is available to show reductions in infections. Is there any data to document the infectious dose of SARS-CoV-2 or sampling methods.
12:34:16 From Neil Zimmerman : I cheated and looked it up on the internet - $500\
12:35:13 From cliff zlotnik : well done Neil "Z-Man" Zimmerman, send your address
12:43:57 From SUSAN VALENTI : Wastewater testing seems to be more reliable
12:51:34 From Tom Phillips : Re: schools: poor HVAC O&M, filter bypass, and failed condensate drains were common problems in big field study in CA, but legislation & funding to address issues was not provided until recently. See 2003 CARB Portable Classroom Study, https://ww2.arb.ca.gov/resources/docume ... ooms-study
13:05:00 From Tom Phillips : thanks ED!
13:05:06 From Radio Joe : Cyrus the Virus a new classic
13:06:40 From Victor Cafaro : Nice song
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Re: Episode 652: Ed Light, CSP, CIH - Practice to Research: IEQ Lessons from the Real World

Post by RadioJoe »

It's always a pleasure talking to Ed LIght. His passion for the industry shines through in every interview. Still plugging away when many would be kicking back enjoying their retirement Ed continues to help keep the public healthy with his work and his contributions to practice to research!
Thanks Ed!
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Re: Episode 652: Ed Light, CSP, CIH - Practice to Research: IEQ Lessons from the Real World

Post by CliffZ »

Episode 652 | January 21, 2022 | 12:00 PM EST
Ed Light, CSP, CIH
Practice to Research: IEQ Lessons from the Real World

Ed Light is a blend of practitioner and scientist.
Ed Light is humble.
Ed Light isn’t afraid to speak his mind.
Ed Light isn’t afraid to question the status quo.
Ed Light seeks practical cost effective solutions.
Ed Light seeks to learn from every project.
Ed Light shares his information.

Nuggets mined from today’s episode:

• As a kidney transplant recipient, Ed is immunocompromised and needs to be very careful. He has faith in and relies upon an N95 mask.
• Epidemiology is based on disease transmission.
• Much of the Covid data Ed has reviewed isn’t practical, is misleading and is based on insufficient and incorrect sampling.
• Opines that most Covid transmission is close range.
• Little data to support long range Covid transmission through HVAC systems.
• Poor ventilation and airflows can concentrate Covid.
• Sewage and sewer gas are paths of Covid transmission.
• Flushing toilets aerosolizes droplets and pathogens. Most public washrooms do not have toilet covers. Electric hand dryers in washrooms disrupt normal washroom airflow patterns. Opines that restroom stall doors be open between uses.
• On the Diamond Princess cruise ship there were no new cases of Covid due to viral contamination of the ship’s HVAC system.
• The Chinese restaurant case of long-range spread was related to viral concentration due to poor air circulation, not the HVAC system.
• Portable HEPA air cleaners can disrupt normal airflow patterns and push viral laden air into worker breathing zones.
• UV light works well in healthcare and is unproven in other types of buildings.
• Fear tactics are being used to market new stuff. There is no data to support “new stuff”. Millions of dollars has been spent on unproven “new stuff”.
• Covid transmission via fomites is infrequent.
• Ed has been working with schools in the areas of: safety, industrial hygiene and engineering for over 40 years. Ed is disappointed with schools response to Covid who wasted money on unproven “new stuff and gizmos” rather than investing in improving ventilation and fixing broken HVAC systems.
• Ed is an advocate of masking, social distancing and screening.
• ED is an advocate for maximizing ventilation and repairing broken equipment.

IAQ researchers and practitioners have played an active role in responding to the COVID pandemic, focusing on specific changes to building O&M.
But has this actually made a difference? Can we do better?

This presentation steps back for an overview of the building response strategies we have put in place based on my review of epidemiological studies. While ongoing epidemiological evaluation has been critical to tracking the spread of COVID-19 and making overall public health decisions, it has been largely overlooked in the implementation of operations and maintenance changes to minimize transmission in buildings.

Close Range, Long Range, HVAC, Sewage, Surface Contact

Critical issue for control strategy is close- vs. long-range transmission:
● Long-range potentially associated with HVAC, ventilation and filtration
● Close-range not significantly influenced by HVAC

Building Dynamics based upon: Based primarily on:
- Aerosol science - Mechanical engineering
- Hygiene


● Assumptions behind guidance to maximize ventilation and filtration:
○ Long-range transmission is dominant
○ Infectious virus circulates through HVAC
● Assumptions behind promotion of portable filters, UV and air treatment:
○ Efficacy based on limited removal data (not representative of overall exposure reduction).
○ Generally effective throughout space (doesn’t consider lack of control over close-range transmission).

Understanding & Controlling Airborne Pathogens
● Epidemiology is the bottom line-
While other research estimates exposure and theoretical risk, epidemiology is based on actual disease transmission.
● Although epidemiology has played a major role in tracking COVID, few studies have considered environmental factors or O&M interventions.
● Epidemiological evaluations which could consider the contribution of environmental factors and the impact of interventions include:
● Population studies
● Outbreak investigations
● Contact tracing
● Case/Control research

1. Most transmission is close-range 16 studies
2. Long-range transmission is infrequent and generally associated with very poor ventilation 11 studies
3. No evidence supporting transmission by HVAC recirculation No studies
4. Fomite transmission infrequent. 4 studies
5. Sewer gas has been associated with COVID transmission 4 studies


● COVID research should focus on determining the prevalence of transmission routes and the efficacy of response measures.
○ Epidemiological evaluation and sampling of infectious virus in buildings are particularly important in this regard.
● COVID response strategies in buildings should focus on measures established to reduce transmission.
○ Cost-effective resource allocation should recognize the importance of administrative infection control measures and consider lower-cost options for enhancing O&M.

ED's Filter Project
For several years, upgrading of HVAC filters have been advocated as a measure to reduce exposure to fine particulates to improve occupant health. This study compared the use of MERV 13 vs. MERV 8 in a school. This was conducted by our team of industrial hygiene and mechanical engineering consultants for a school district on a very limited budget. In this context, it did not have the rigor and detail of a funded research study. It did follow a unique methodology for field evaluation of filter performance and an updated literature review of health effects of indoor particulates.

The elementary school was well set up for a comparative study, with 12 similar
HVAC zones, each including several classroom and served by rooftop units.

 Data showed that controlling particles better lowered incidence of asthma and allergy in sensitive populations.
 Data showed that poor fitting filters are the equivalent of no filters.

Contact info for:
Ed Light, CIH
Building Dynamics, LLC

Z-Man Signing Off

In the 1972 movie Deliverance actor Billy Redden portrayed the inbred hillbilly banjo player, how much was he paid for his performance?
Answer: $500
Answered by: Neil Zimmerman, PhD, 1600 W. Green Tree Rd, Apt. 119, Glendale, WI
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