wintermeindoorand) outdoorpm 2.5)measurements indoor v...wintermeindoorand) outdoorpm...
TRANSCRIPT
Winter'me Indoor and Outdoor PM2.5 Measurements
-‐ or -‐ Does it really do us any good to stay inside on those winter'me inversion
days? Dr. Randy Mar'n
USU/UWRL Civil & Env. Eng.
Logan, UT [email protected]
(435) 797-‐1686
PM2.5 Composi'on (part of the key)
Modeled chemical specia.on from UDAQ’s 2012 State Implementa.on Plan (SIP) when PM2.5 > 25 µg/m3
NH4NO3 ranged from 63-‐70% across SLC sites
NH4NO3(p) ↔ NH3(g) + HNO3(g)
Note: This is an equilibrium reac'on and is a strong func'on of temperature and rela've humidity
NH4NO3 up 80-‐95% on high PM2.5 days
Calculated Equilibrium Coefficient (Kp = [NH3]*[HNO3])
Change from freezing to room temperature
0% RH
90% RH
Kp changes by greater than 2
orders of magnitude (≈240x)
Therefore, warmer (indoor vs. outdoor) temperatures should result in vola'liza'on of par'culate NH4NO3 to gaseous components NH3 and HNO3
Cache Valley Indoor vs. Outdoor PM2.5 • 2005: Filter-‐based PM2.5 MiniVol impactor samplers inside & outside at the area schools
• Sunrise, Summit, & Greenville Elementary schools; Logan High School
• Tests run only during weekdays and school hours • Samplers also analyzed for some chemical cons'tuents (anions – esp. NO3
-‐)
• 2013: Filter-‐based PM2.5 MiniVol impactors inside USU buildings compared to UDAQ Logan TEOM PM2.5
• Engineering Bldg, Taggard Student Center, & Field House (rec. center) • 24-‐hr collec'on (midnight-‐to-‐midnight); every other day
• Real-‐'me op'cal par'cle data also collected
• 2014: Filter-‐based PM2.5 MiniVol impactors various buildings compared to UDAQ Logan TEOM PM2.5
• 18 different buildings, six to seven 24-‐hr samples at each site • 5 private residences, 2 high schools, 1 elementary school, 1 church, 1 public library, 2 re'rement homes, 1 hospital, 3 USU buildings, 1 commercial gym, Utah Water Research Lab (UWRL)
• OPC data at some sites and IC analysis of selected filters yet to be completed
How does the MiniVol sampler collect only PM2.5 Par'cles? • Air is pulled through a special separa'ng part called an impactor
• The impactor “jet” makes the air flow speed up to a specific velocity
• Large par'cles can’t turn around the impactor “plate” and are trapped
• Small par'cles (PM2.5) are then collected on a filter
Filter (for par'cle collec'on)
Small Par'cle (PM2.5)
Large Par'cle
Impactor Jet (speeds up air flow)
Impactor Plate (removes
large pr'cles)
Clean air out
The AirMetrics Impactor PM2.5 MiniVol Air Pollu'on Sampler
PM2.5 Impactor Head
Sample Filters (47 mm TFE)
Clean filter – before use Filter – auer use
Indoor PM2.5 vs. Outdoor PM2.5 2005 and 2013 Results
Or…on days high days Indoor ~
23% Outdoor
2005 Chemical (ionic) Composi'on of Collected PM2.5
0
1
2
3
4
5
6
7
8
Chlorine Nitrate Sulfate
Ave
rage
Con
cent
ratio
n (µ
g/m
3)
Indoor Outdoor
Indoor PM2.5 vs. Outdoor 2013 real-‐'me (OPC) par'cle tracking
2014 Mul'-‐Site Indoor/Outdoor PM2.5 Comparisons
Jan. 16-‐26, 2014
Jan. 8 – Feb. 9, 2014
Feb. 11-‐23, 2014
2014 Mul'-‐Site Indoor/Outdoor PM2.5 Comparisons
Previous linear rela.onship:
y = 0.07x + 8.21
Summary/Conclusions
• Is “remaining indoors” during inversions an adequate protec've measure? • Yes!….in reference to CV’s ambient PM2.5 • indoor PM2.5 always found below NAAQS • studies over different years/buildings similar
• consistent with dominant NH4NO3 composi'on
• These studies do not necessarily indicate indoor air is “safer” • addi'onal indoor sources of PM and other pollutants may be significant…..
USEPA Risk Rankings 1. ('e) Worker exposure to chemicals 1. ('e) Indoor radon 3. Pes'cide residue on foods 4. ('e) Indoor air pollutants (non-‐radon) 4. ('e) Consumer exposure to chemicals
(includes cleaning fluids, etc.) 6. Hazardous/toxic air pollutants 7. Deple'on of stratospheric ozone 8. Hazardous waste sites (inac've) 9. Drinking water (radon and THMs) 10. Applica'on of pes'cides Others (including groundwater contamina'on at 21, NAAQS at 22, etc.)
Risk of cancer/death -‐ breathing indoor air as high as 0.5 to 1% (conven'onal risk assessment) Corsi, Environ. Manager (2000)
Acknowledgements • UWRL and USU’s Dept of Civil & Env. Eng. for par'al funding and support
• USU Facili'es
• Logan & Sky View High Schools
• Greenville, Summit, & Sunrise Elementary Schools
• Logan city and the Logan Public Library
• Gold’s Gym (Logan, UT)
• Logan’s 1st Presbyterian Church and Pastor Paul Heins
• Dr. Laurie McNeill
• Sunshine Terrace Founda'on
• Pioneer Village
• Cache Valley Hospital
• Utah Division of Air Quality (UDAQ) and the Utah Air Monitoring Center (UAMC)
• USU students Kori More, Vishal Doshi, Clay Woods, Trinity Stout, McKay Johnson, and Andrew Lewis
Exciting New Research!
Tailpipe measurements of NOx, HC, CO, and CO2 as a func'on of cold start, hot start (10 & 20 min), and idle
2007 Dodge Ram 1500
• Analysis will ul'mately es'mate total emissions for cold starts vs. hot starts vs. idling • Note: Even under cold start, catalyst reaches op'mal efficiency in 1-‐2 minutes