Episode 669: Dave Dorman, DVM, PhD - Rima Habre, ScD - Megan Harries, PhD - NASEM - Why Indoor Chemistry Matters

Where the IAQ Radio Discussion Continues
Post Reply
User avatar
admin
Site Admin
Posts: 51
Joined: Wed Aug 18, 2021 3:06 pm

Episode 669: Dave Dorman, DVM, PhD - Rima Habre, ScD - Megan Harries, PhD - NASEM - Why Indoor Chemistry Matters

Post by admin »

Show Resources: Show Discussion:

12:05:44 From cliff zlotnik : Name the collection of unsaturated bicyclic monoterpenes as the majority liquid extract of conifers?
12:06:02 From cliff zlotnik : trivia question is above
12:07:09 From Jonathan Faith : https://nap.nationalacademies.org/resou ... lights.pdf
12:07:43 From Megan Harries : the full report can be found at the National Academies Press site: https://nap.nationalacademies.org/catal ... ry-matters
12:24:10 From Ed Light : What is your opinion of concentration limits currently in use to judge VOC levels in indoor air? These include guidelines for acceptable health risk, such as the California CRELS, and acceptable levels for classification as a LEED building. My review of these criteria found no supporting data based on actual health effects in exposed occupants at these levels (parts per billion). Also, these criteria overlap with the range of background concentrations typically found indoors.
12:26:05 From steven.corpuz : When we talk about cooking, are we talking about the cooking smoke or off gas from NPG or propane
12:31:07 From steven.corpuz : And the ability of the actual cook
12:33:02 From Danny Gough’s iPad : Perhaps my grandparents had an innovative idea with the kitchen in a separate building than the living space.
12:33:48 From cliff zlotnik : Danny, it worked then and would work now : )
12:38:17 From Ed Light : To clarify my previous question, I could not find any toxicological or epidemiological studies based on human exposure establishing thresholds of concern for VOCs at the levels specified by IAQ standards. Am I missing anything please follow up this program with citations supporting actual health effects at these low levels? Did NAS consider recommending that we stop making decisions based on these standards, which I consider arbitrary and misleading?
12:51:35 From steven.corpuz : Is this similar to Ozone cleaning for CPAP machines?
12:52:44 From Ed Light : It sounds like NAS may not have considered studies showing filters in use, including activated carbon, offgas VOCs back into the air.
12:53:12 From Danny Gough’s iPad : And yet there is substantial anecdotal evidence some of these devices do provide benefit. Is it possible the benefits are real, but the science just hasn’t identified those elements?
12:54:28 From Danny Gough’s iPad : It’s akin to the idea, if you can’t measure it, it doesn’t exist. But it’s just as probable we don’t know how to measure it.
12:54:57 From Megan Harries : here's the microbiomes report from 2017: https://nap.nationalacademies.org/catal ... for-indoor
12:59:39 From cliff zlotnik : correct Vic send your address
User avatar
CliffZ
Posts: 40
Joined: Thu Sep 09, 2021 3:36 pm

Re: Episode 669: Dave Dorman, DVM, PhD - Rima Habre, ScD - Megan Harries, PhD - NASEM - Why Indoor Chemistry Matters

Post by CliffZ »

Nuggets mined from today’s episode:

Link to 4 page report summary: https://nap.nationalacademies.org/resou ... lights.pdf

Overview of the document.
The National Academy of Sciences can be traced back to Abraham Lincoln. The Academy advises the government on scientific issues. Researchers provide their services pro bono. Areas of interest for the report included new findings and underreported chemical species.
Main Messages of the Document:
Indoor environmental chemistry is widely variable.
Indoor Chemistry is a Complex Exposure because we spend most of our time indoors.
Researchers know little about indoor chemistry.
Indoor chemistry changes over time.
Indoor chemistry effects human health.
We live in a changing world. (e.g. climate change, wildfires, urbanization, etc.)
Indoor chemistry is studied with analytical methods and equipment. We need improved analytical methods, tools, equipment and sensors.
Science is translated into practice and policy.
Role of human activity in indoor chemistry.
More investment needed.
Need to communicate the science and the risks.
The team is proud of the research and efforts that went into developing the report.
Need to have multiple disciplines collaborate and then translate their work into practice.

The study was sponsored by the National Institutes of Health, Department of Health and Human Services, Centers for Disease Control and Prevention, Environmental Protection Agency, and SLOAN.

PARTITIONING OF CHEMICALS IN INDOOR ENVIRONMENTS-
“Partitioning of Indoor Chemicals Partitioning refers to both the thermodynamic state of chemicals distributed among phases in a system and the processes that transfer chemicals among phases. Partitioning determines the concentration of a chemical in air, on surfaces or elsewhere and distributes chemicals from their initial sources throughout indoor spaces, to air, building materials, furnishings, dust, and so forth. For example, phthalates emitted from plastics can partition to surfaces, porous materials, settled dust, and other compartments. These compartments buffer the air concentrations of chemicals, reducing the short-term effectiveness of controls by ventilation or filtration. Partitioning also influences occupant exposure to chemicals. For example, partitioning of indoor chemicals to aerosols increases inhalation exposure, while partitioning to dust and surfaces increases ingestion exposure, especially by toddlers.”

VOCs are not a chemical, rather a range of homogeneous products.

When looking at PRIMARY SOURCES AND RESERVOIRS OF CHEMICALS INDOORS what unexpected or underappreciated sources were reported? Human activity is a primary source. Dust is a reservoir of chemicals, new flame retardants are found in dust, old flame retardants “legacy chemicals” are also found in dust. Dust exposure is via oral, dermal and inhalation routes.

What kind of future research in this area will help us do a better job creating and maintaining healthy indoor environments? We don’t have a good handle on the disclosure of ingredients of consumer products due to trade secret protection. Research is analytically driven. We critically need real time monitoring of real world environments. Exposure is a factor of time.

Please explain what PARTITIONING OF CHEMICALS IN INDOOR ENVIRONMENTS is and how it’s important to people’s overall exposure to chemicals in the indoor environment? Time scales, the lifetime of a chemical is greater in dust. Exposure changes when chemical phase changes (e.g. oral, dermal, or inhalation). Chemicals can be in dust, organic, gaseous, or liquid phase. Heat, moisture can cause chemicals to emit. Moisture causes hydrolysis.

What variables affect partitioning that IEP’s can help with now? While we can remove the dust we see, dust can also be found in inaccessible areas: attics, interstitial spaces and HVAC systems. Air cleaners can trap chemicals. Air cleaners can also re-volatize chemicals when turned off. Subtractive processes (filtration, activated carbon adsorption and ventilation are recommended over chemical additive processes.

When it comes to the CHEMICAL TRANSFORMATIONS and MANAGEMENT OF CHEMICALS IN INDOOR ENVIRONMENTS our audience also includes restoration contractors and HVAC contractors that are commonly pitched on equipment that uses ozone, hydroxyls, TO2, etc. What is the takeaway from these chapters for these practitioners? Device testing is currently not mandated. Device testing is not performed to a uniform standard. Testing done in a “shoe box” is extrapolated to reflect what occurs in a much larger space in the real world. This results in hype and unsubstantiated claims.

Link to 4 page report summary: https://nap.nationalacademies.org/resou ... lights.pdf

Link to download entire report:
https://nap.nationalacademies.org/login ... 6228&page=

Link to locate microbiomes report:
https://nap.nationalacademies.org/catal ... for-indoor

Z-Man signing off

Trivia:
Name the collection of unsaturated bicyclic monoterpenes as the majority liquid extract of conifers?

Answer: Pinene, answered by Victor Cafaro
User avatar
RadioJoe
Posts: 38
Joined: Thu Aug 19, 2021 3:58 pm

Re: Episode 669: Dave Dorman, DVM, PhD - Rima Habre, ScD - Megan Harries, PhD - NASEM - Why Indoor Chemistry Matters

Post by RadioJoe »

Why Indoor Chemistry Matters is an important inflection point in how we look at indoor environments. For 50 years we have looked at CO and CO2 and Formaldehyde, Lead, Asbestos, particulate, mold and the elusive VOC's. Now we are seeing that grandma was correct and its all of these plus more and they are most commonly and controllably in dust. Who controls the dust levels in indoor environments?

This week we set the table then took a deep dive into how the report was set up and what all of this means to those of us with boots on the ground. In part 2 we will be able to go deeper into the management of these contaminants and how those in the trenches can help shape where we go from here. Stay tuned.
Post Reply