Dustin Poppendieck Profile picture
Indoor Air Quality Researcher. Views expressed are my own. No financial interests in HVAC, portable air cleaners or indoor air quality monitors.
Dame Chris🌟🇺🇦😷 #RejoinEU #FBPE #GTTO🔶️ Profile picture Peter English #FBPE Profile picture Aviva Gabriel Profile picture joyfulnoyz 😷 #COVIDIsAirborne Profile picture Beth Blecherman Profile picture 7 added to My Authors
Oct 14, 2022 25 tweets 9 min read
What is the next step to improve Indoor Air Quality (IAQ)?

After the White House summit on Indoor Air Quality (#WHIAQ) many people asked what is next?
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This thread explores EIGHT actions that federal, state, and/or local jurisdictions, along with standard and codes bodies can do NOW to improve IAQ.
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Oct 11, 2022 22 tweets 7 min read
#WHIAQ. Innovations in IAQ

Stephanie Guerra. OSTP. Assistant Director for Health Security and Biodefense.

- Responsible innovation of technologies can help improve IAQ in a wide spectrum of indoor environments.
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@CorsIAQ. It is not going to require rocket science to improve IAQ. We have the tools to do it now. If we do it we will get better health outcomes. We need to make sure we don't leave any community behind. We need accessible tech for IAQ.
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Oct 11, 2022 15 tweets 4 min read
#WHIAQ. Clean Air Benefits Everyone.

Taryn Williams. Ass. Secretary of Labor for Disability Employment Policy. Improving IAQ in schools, homes and workplaces is an issue of equity (YES). Those who vulnerable are more likely to be affected by poor IAQ.
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Kenneth Mendez. Asthma and Allergy Foundation of America. 25 Million Americans have Asthma and 4,000 people die per year (1:13 people). 5 Million children. Asthma is leading cause of missed school days. Cost is up to $82 billion (?). Need better IAQ to reduce triggers.
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Oct 11, 2022 14 tweets 3 min read
#WHIAQ. Why improving IAQ makes good business sense.

Jordan Silberman. Monumental Sports (Capital One Arena in DC). Baseline post pandemic now thinks about more than just security. Created a system to track safety AND IAQ through building wide monitoring.
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Michele Schneider. Salesforce. 6 million sq feet management. Workplace design focused on well being in the past. Now IAQ is on the list and a core value.

Kevin Kampschroer. GSA. The only reasons buildings exist is to take care of people in them (YES).
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Oct 11, 2022 11 tweets 2 min read
#WHIAQ Schools. Alex Marrero. Denver County Public Schools Superintendent.

Jesus Jara: Clark County School District Superintendent.

(Lost the intro thread.... But both have districts that with 10,000s of staff/teachers and 90,000 plus students). 1/ - Clark County has 10,000 homeless students.

- Marroro. Funding and policy. Has spent $25 million on IAQ (MERV 13 filtration as standard and IAQ monitoring). What happens when money ends? Filters need to exchanged. 2/
Oct 11, 2022 4 tweets 1 min read
#WHIAQ. @j_g_allen.

- Our indoor age is 0.9x(age).

- The person who manages your buildings (including your homes) has a bigger impact than your doctor
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- Standards for ventilation are bare minimums when they are actually followed.

- Give buildings a tune up.
Take pulse of buildings regularly (CO2).
- Increase ventilation
- Upgrade filtration
- Need Ventilation METRICS (YES!)
We have enough data to move now.
2/
Oct 11, 2022 4 tweets 2 min read
#WHIAQ. @ashishkjha

- Indoor air quality is the next front for public health.

- Drinking water improvement was a long term systematic change. We need the same effort for IAQ.

- It becomes harder to imaging how our health care system can manage respiratory diseases. 1/ - The single biggest structural change we can make to address respiratory transmission is to improve indoor air quality.

- We need health buildings, because we need healthy communities. 2/
Oct 6, 2022 18 tweets 3 min read
#AAAR2022. Plenary: @IAQinGWN

- A story about filters....

- How to improve indoor air cleaner
1- Keep it dry
2- Source control
3- Ventilation
4- Air cleaning

- Filtration (air cleaning) has the shortest history. Only 50-100 years use in buildings.
1/ - ASHRAE standard 52.2 for filtration is only 23 years old.

- Measured CO2 and PM2.5 decay in a classroom that was supposed to be operated at 6 air changes per hour with ventilation and filtration. But it was actually at ~2 air change per hour.
2/
Oct 5, 2022 5 tweets 1 min read
#AAAR2022, @IAQinGWN.

- Lots of reasons filtration is not optimal.
> energy cost
> too noisy
> filtration replacement cost

1/
- Trade offs between performance and runtime.

- Can they improve on the concentration threshold approach for running the portable filter?

-Unlikely to be universal threshold due to sensor and environment variability.

2/
Oct 5, 2022 4 tweets 1 min read
#AAAR2022. @SarahRHaines

- Indoor dust can be resuspended by human activity. Dust can be use as a tracer to determine the presence/absence of RNA (i.e. SARS-COV2).

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- Deployed indoor air cleaners in homes/classroom where people who COVID positive.

- In home cleaners placed in isolation room, outside and in the main living area. After 1-2 weeks dust was removed from filters => extracted => qPCR analysis.

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Oct 5, 2022 4 tweets 2 min read
#AAAR2022. @LioraMael

- How do homes recover when impacted from wildfires.

- @LioraMael notes that her home burned down in the Marshall fire the day before she was to move in. #RealworldImpacts
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- Looked particulate matter in a house on the edge of the Marshall fire roughly one month after the fire.

- Cleaning activities increased the particle concentrations in the home.
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Oct 5, 2022 4 tweets 1 min read
#AAAR2022. Xiaochen Tang.

- Does long term exposure of Tobacco Specific Nitrosamines (TSNAs) lead to negative health impacts.

- Previous research shows TSNAs stick to surfaces. TSNAs hard to measure due to reactivity (esp NNN, NNK).
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- Added HONO enriched air to chamber with cloth coated with nicotine to create TSNA. Examined cellulose and cotton with/without sweat and skin oil.
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Oct 4, 2022 4 tweets 1 min read
#AAAR2022. @ProfPeteD. ALPACA Project Overview

- ALPACA - Investigation in artic air quality in urban artic environments.

- When it is -14F(?C) people are inside. But in Fairbanks there is a high prevalence of wood burning stoves.

1/
- What happens when you move polluted air from outdoors indoors with a 50 C temperature difference?

- In general outdoor PM10 concentrations higher outdoors than indoors, EXCEPT when pellet stove was used inside the house. 2/
Oct 4, 2022 4 tweets 1 min read
#AAAR2022. @etgall

- Can you use consumer grade sensors be used to estimate particle infiltration.

- Survey asking what mitigation method they used during wildfires: main response stay indoors and keep windows and doors shut.
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- Corrected Purple Air sensor measurements to reference station.

- Outdoor PM2.5 concentrations varied by over a factor of 2 outdoors over 25 km during wildfire.

- Indoor concentrations varied from equal to outdoor data to order of magnitude lower than outdoor.
2/
Oct 4, 2022 4 tweets 1 min read
#AAAR2022. Pradeep Prathibha. USEPA

- Do DYI filters help during wildfire events?

- For this study looked a 1 filter taped to a fan (not 4 filters and fan of #CorsiRosenthalBox) 1/ - Looked a Hoopa tribe spring/fall interventions in Northern CA at 8 homes.

- Compared two weeks of no air cleaner/DYI/commercial air cleaners. 2/
Oct 4, 2022 4 tweets 1 min read
#AAAR2022. @EarthMechanic

- What happens on surfaces when wildfire smoke comes indoors?

- Indoor surface films are complicated, diverse, chemical mixtures, patchy and remain for periods longer than the air change rate (weeks/months).

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- Gas surface reactions can happen. But so can reactions WITHIN the condensed phase film.

- You can find third hand smoke tracers in houses of people who don't smoke.

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Oct 4, 2022 5 tweets 2 min read
#AAAR2022. @kjmayer4. (disclosure: I was involved in this study)

- Cited study showing in 2020 over 25 million Americans (8%) experienced >100 ug/m3 of PM2.5.

- #CASAChem Experiments looked at the impact of long range smoke impacts.
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- Examined 1) fresh smoke, 2) fresh smoke plus ozone, 3) aged smoke.

- Ozone addition to fresh smoke did not change the particle composition or sized distribution significantly indoors.
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Oct 4, 2022 5 tweets 2 min read
#AAAR2022. @ChemDelphine discusses #CASAChem study (full disclosure I was involved).

- CASA was a huge collaborative research group project to investigate indoor chemistry experiments related to wild fires, ozone, and surface aging. 1/ - "Clean air act has really worked." With respect to sulfate.

- But wildfire smoke is still a big driver. 2/
Oct 4, 2022 14 tweets 3 min read
#AAAR2022. @Smogdr Plenary:

- The world needs more scientists and engineers working on public health (fact check; True!)

- Exposure to PM2.5 is the second leading cease of years lost of life (DALYs). (fact check: this includes exposure from cookstoves). 1/ - We aren't allowed to choose the air we breathe. We breathe what we get.

- The hazard ratio increases from 1 to 1.1 when PM2.5 goes from 2.8 to 14 ug/m3 equating to about 60,000 increased deaths per year in the US. 2/
Oct 4, 2022 4 tweets 3 min read
Excited to attend my first AAAR conference today in Raleigh, NC.

Looking forward to meeting twitter friends I have never met in person, some great talks from the #CASAChem and ALPACA projects and learning new aerosol science.

1/2 Image I will be live tweeting this week with the #AAAR2022 hashtag. Follow along with AAAR Social Media Ambassadors @DaveyRachel1, @ClaraOak24, @colleenesterase& @kapur_sukriti who will also be live tweeting.

And yes, mask are mandatory. 2/2 Image
Sep 29, 2022 9 tweets 3 min read
Why do peak CO2 concentrations change from one day to the next for the same room?

Let's look at what may change on a daily time scale and impact ventilation:

- People
- Weather

Let's focus on the second one today (assuming same people and activity level). 1/9 Wind blowing on a building results in high pressure on the upwind side of the building, low pressure on the downwind side. This pressure difference can suck air into the building, increasing the ventilation rate. 2/9