Emerging Air Sensors:
Challenges and Opportunities
Donnie RedmondNC DAQ Ambient Monitoring
DisclaimerI have no particular expertise with these new
sensorsI’m not a tech geek
… but I live near RTP and can go to the workshops!
Recent NC ExperiencePermit hearing comments on cement plant at the coast
Medical doctor did survey with hand-held monitor “Followed sampling protocol used in academic research”“PM 2.5 levels ranging from mid-30 to mid-40 μg/m3. The
EPA’s current standards state that levels should not exceed 12 μg/m3.”
“Real-time monitoring differs from the NC DAQ monitoring protocol in that these monitors measure actual exposure levels of PM 2.5 directly in real life settings—parents strolling their babies, children playing in parks, young and mature adults running, playing sports and bicycling.”
NC DAQ monitoring station is “remote” and “offline”Hearing officer response … Wow, this looks pretty bad!
Apples and OrangesTSI 8534 Hand Held Dusttrak DRX
Industrial dust monitorDevice is not an FRM or FEM
Took a five-minute average at each locationCompared it to daily standard (12 μg/m3)
Essentially a three-year average of 24-hour averagesWould not have violated the annual standard (35 μg/m3)Did not take any readings at our monitor
Siting questionsSites used not likely suitable for ambient monitor
FRMs are non-continuous; FEM has maintenance periodsFollow our webpage for one-hour spikes on continuous
monitors
The more important issueCitizens aren’t going to understand the EPA
standards and siting requirementsThey don’t know the difference between
FRM, FEM, BAM, TEOM, PM10, PM2.5, TSP, 1-in-12, etc
They may not even trust the government monitoring
But they have these new gadgets and they’re gonna use them!What are we going to do about?
North Carolina perspectiveChallenges*
Citizen groups “Ah ha! Now we can do our own testing and see what
the government has been hiding from us!”Management and bean counters
“This stuff is cool and a lot cheaper than what you’re doing!”
Monitoring staff “Those things are all junk and they don’t work!
(Thinking: Uh oh! What if this stuff works and they don’t need me anymore?!)”
* Donnie’s real or perceived challenges
North Carolina perspectiveOpportunities!New tools to
Respond to citizen complaintsTarget compliance activitiesMore data for modelersSupplement ambient network to better select
sitesBut must be able to “trust” the
technology
Respond to citizen complaintsOdors
Animal operationsGasoline vapor recovery
SuspicionsNot in my neighborhood
Target compliance activities“Drive by” spot checks
Mounted in regional office staff vehiclesLess reliance on visible emissions or
complaintsScreening only – not basis for actual
enforcementFollow up with more traditional methods
More data for modelersThey are accustomed to imperfect data
Vehicle counts, emissions inventories, met dataLocal data preferred over national default
valueImperfect ambient data still useful
Focus on relative vs. absoluteTweak the model to resemble what really
happened
Supplement ambient networkSite location
Instead of modeling or guessingArray of inexpensive devices
Absolute values may be off Pay attention to relative values
Fill in gaps in network
Can you “trust” the technologyKnow the limitations of specific devicesFast, cheap, or good – pick two
Attainment monitor: must be goodAccept higher uncertainty for other purposes
Initial complaint response: fast and cheap Maybe ±30% is good enough for screening
Info, verificationNot only have technical info available but
Some level of training for the folks who are selling, operating, and using the data Sales reps may not understand what they’re
offering Non-technical operators/users who don’t know
CO from CO2 75 ppb from 0.075 ppm
Managing expectationsMaybe it gives you a number
It’s still not an FRM
NWS has been hereNational Weather Service has learned how to
incorporate data gathered by the public
“The Citizen Weather Observer Program (CWOP) is a public-private partnership with three main goals: 1) to collect weather data contributed by citizens; 2) to make these data available for weather services
and homeland security; and 3) to provide feedback to the data contributors so that
they have the tools to check and improve their data quality. In fact, the web address, wxqa.com, stands for weather quality assurance.”
SummaryProbably very useful tools coming out!
Expect them to supplement (not supplant) existing network
Need means to sort out the good stuff from junk
Questions?Donnie Redmond
North Carolina Division of Air Quality Ambient Monitoring Section Chief
