Real Time Dust Monitoring Strategies and Tools

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Muriel Arnold
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Sound pressure level meter + Data logging noise dosimeter + RF Survey meter + PID / FID + Geiger counter + Confined Space

1 Real Time Dust Monitoring Strategies and Tools Indiana H&S Conference Scott Norman, CIH CSP Product Specialist TSI Incorporated Shoreview MN TSI Incorporated Real time measurement instruments + Speedometer + Altimeter + Thermometer + Scale + Sound pressure level meter + Data logging noise dosimeter + RF Survey meter + PID / FID + Geiger counter + Confined Space 4-gas monitor Oregon Department of Transportation Do you know how fast you were going? 2 1

2 Goal to introduce some strategies and associated tools used for monitoring dust in real-time. What are aerosols How do we measure aerosols Types of real time aerosol measurement instruments How light scattering photometric instruments work Strengths and limitations of these instruments Application examples Q&A 3 Aerosol + Dust 4 2

3 Aerosol + Dust + Fume 5 Aerosol + Dust + Fume + Mist 6 3

4 Aerosol + Dust + Fume + Mist + Smoke 7 Aerosol Size Matters 8 4

Respiratory Tract + Extrathoracic region >PM 10 + Tracheobronchial region PM 10- PM 4 + Alveolar region <PM 4 Based on International Commission of Radiological

5 Respiratory Tract + Extrathoracic region >PM 10 + Tracheobronchial region PM 10- PM 4 + Alveolar region <PM 4 Based on International Commission of Radiological Protection (1994) and U.S. Environmental Protection Agency (1996a). Air Quality Criteria for Particulate matter, 2004, p 6-5. TSI Incorporated 9 How Big Click to open How Big 10 5

6 Measurement of Aerosols Traditional IH Air Sampling Equipment + Pump + Sampling Cassette + Media + Cyclone + Tubing Pump 11 Measurement of Aerosols Traditional IH Air Sampling process steps + Calibrate pump + Place on worker, turn on pump + Record start time + Turn off pump, cap cassette, document time + Post-calibrate pump + Calculate run time + Document run times, calibrations, sample ID + Prepare chain of custody form + Package for shipping + Complete shipping paper work Pump 12 6

Sept 12, 2001 Wikipedia, source NASA 13 Do we evacuate or shelter? U.

7 This image cannot currently be displayed. How fast do you need the data? Aerial photograph of Manhattan, NY. Sept 12, 2001 Wikipedia, source NASA 13 Do we evacuate or shelter? U.S. Air Force photo/master Sgt. Wally Bacio

Real Time Aerosol Measurement Instruments + Beta Attenuation Monitor (BAM) + Tapered Element Oscillating Microbalance (TEOM) + Piezoelectric Microbalance + Aerodynamic Particle Sizer (APS) +

8 Real Time Aerosol Measurement Instruments + Beta Attenuation Monitor (BAM) + Tapered Element Oscillating Microbalance (TEOM) + Piezoelectric Microbalance + Aerodynamic Particle Sizer (APS) + Differential Mobility Analyzer Spectrometer (DMS) + Integrating Nephelometer (Photometer) + Condensation Particle Counter (CPC) + Optical Particle Counter (OPC) 15 IH-based field instruments + Photometers + Optical Particle Counters + Condensation Particle Counters DustTrak DRX 8533 Photometer AeroTrak 9306 OPC P-Trak 8525 CPC 16 8

Light Scattering Photometer Technology Aerosol Inlet HEPA Filter Orifice Sheath Air Light Trap Optics Chamber Laser Beam Mirror Beam Shaping Optics Laser Diode Exhaust Pump Viewing Volume Photo

9 Light Scattering Photometer Technology Aerosol Inlet HEPA Filter Orifice Sheath Air Light Trap Optics Chamber Laser Beam Mirror Beam Shaping Optics Laser Diode Exhaust Pump Viewing Volume Photo Detector Gravimetric Filter Protection Filter Dampening Chamber 8533 DustTrak DRX Flowmeter 17 Optical Particle Counter (OPC) Optical Particle Counter (OPC) light scattered by individual particles traversing a light beam is detected at various angle. These signals are interpreted in terms of particle size via calibrations. 18 9

10 Condensation Particle Counter (CPC) Three Basic Components 3. Optics Each particle passes through a laser, scattering light Each light scatter pulse is counted 2. Condenser Cooled to condense vapors onto particles, particles grow 1. Saturator Heated to saturate sample with isopropanol vapor How these instruments work 20 10

$+Density + Refractive Index + Size$

11 Aerosol Basics Physics of aerosols + Properties +Behavior + Measurements 21 Aerosol Characteristics +Size +Shape +Density + Refractive Index + Size Distribution 22 11

$Aerosol properties + Aerosols absorb, reflect, refract and diffract light$ properties of the aerosol. 23 Particle counting vs.

drops or snow flakes that hits the window + OPCs count the number of

12 Aerosol properties + Aerosols absorb, reflect, refract and diffract light + Light passing through an aerosol concentration is affected by the properties of the aerosol. 23 Particle counting vs. light scattering + Particle counting is like counting the number of rain drops or snow flakes that hits the window + OPCs count the number of raindrops (or snow flakes) hitting the windshield. + CPCs count the number of ultrafine particles 24 12

25 Calibration aerosol + Photometers are calibrated to a test aerosol with

13 Photometric light scattering + Photometers measure the amount of light scattered by the fog. + thicker fog is brighter. 25 Calibration aerosol + Photometers are calibrated to a test aerosol with known properties + A bucket of golf balls will not weigh the same as a bucket of ping pong balls

$+ Size + Shape + Density + Refractive Index + Size Distribution 27 Aerosol concentration$

14 Calibration factor + Calibration factors adjust the instrument response to the difference between the sampled aerosol and the test aerosol. + Size + Shape + Density + Refractive Index + Size Distribution 27 Aerosol concentration measurement range Photometers OpticalParticle Counters Condensation Particle Counters to to 70 0 to 500,000 mg/m 3 particles/cm 3 particles/cm

Particle Size Range for Aerosol Instruments Nanoparticle Thoracic Respirable Inhalable (Total dust) TSP OPC Photometer CPC-alcohol Diffusion Charger SMPS CPC - Water 0.001 0.

15 Particle Size Range for Aerosol Instruments Nanoparticle Thoracic Respirable Inhalable (Total dust) TSP OPC Photometer CPC-alcohol Diffusion Charger SMPS CPC - Water Particle Size Range (micrometers) Photometer: 0.1 to 15 µm Optical Particle Counter 0.3 to 25 µm Condensation Particle Counter 0.02 to 1 µm 29 Aerosol Size Distribution + A photometer sees aerosols of all shapes and sizes + The photometer measures the light scattering of these particles as a group. + Mass is calculated based on the properties of the calibration aerosol. Fly ash FHWA.dot.gov 30 15

16 Strengths and limitations of photometers 31 Limitations + Calibrated to test aerosol + Humidity effects + Contaminated optics 32 16

17 Calibrated to test aerosol + Precise instrument response to all aerosol +Response to aerosol similar to calibration aerosol will more closely match actual gravimetric result +Use side-by-side gravimetric results to develop custom calibration factors (K factors) 33 Diesel Particulate Matter Photometer Correction Factor University of Utah Study + Compare DustTrak 8020 to NIOSH 5040 sampling results for DPM. + 7 trips to underground hard rock mines in Utah and 3 trips in Montana Gravimetric DustTrak K factor µg/m 3 µg/m AVG K factor K factor = (gravimetric mass) / (photometric measurement) 34 17

Diesel Particulate Matter Photometer Correction Factor University of Utah Study 16.00 14.00 Filter Concentration (mg/m 3 ) 12.00 10.00 8.00 6.00 4.00 y = 1.3x + 0.36 R² = 0.95 P <0.001 2.00 0.00 0.000 2.

18 Diesel Particulate Matter Photometer Correction Factor University of Utah Study Filter Concentration (mg/m 3 ) y = 1.3x R² = 0.95 P < Direct Read Instrument Concentration (mg/m 3 ) DustTrak concentration readings are highly correlated to filter concentration measurements. 35 Diesel Particulate Matter Photometer Correction Factor Customer data Gravimetric DustTrak K factor µg/m 3 µg/m Avg K factor K factor = (gravimetric mass) / (photometric measurement) 36 18

19 Photometer K-Factors Photometric Calibration Factor Factory Calibration 1.0 Respirable Silica (1) Wood Smoke (4) 0.64 DPM (1) DPM(2) OutdoorAmbient Urban Pollution (3) 0.38 (1) University of Utah Rodney R. Larson, et al. (2) TSI Metal Mining Customer, 2014 (3) Wallace, et. al, Journal of Exposure Science and Environmental Epidemiology, (4) McNamara, et al, Aerosol and Air Quality Research, 11: , Humidity effect +Hygroscopic aerosols swell as humidity levels increase +Photometric instrument readings will be elevated in humid conditions +Inlet conditioners to reduce the effects of humidity are added to photometric instruments for long term environmental monitoring 38 19

20 Optic contamination +High aerosol levels can result in contaminated optics and measurement drift + Zeroing the instrument regularly helps correct +Use size selective inlet conditioners to sample only small size fractions 39 Strengths + Consistent measurement +Real-time +Data logging +Alarms 40 20

21 Consistent Measurement Performance: DustTrak DRX VS TEOM TSI Application Note EXPMN Real time data How far down wind do we need to evacuate people? 42 21

22 Data logging Peaks Customer data Avg = mg/m 3 Max = 1.11 mg/m 3 What caused this spike? 43 Data logging Historical Trends 0.6 Daily average dust levels mg/m Days 44 22

23 Alarms + Audible or visual notification at selected levels. + Stop the work and adjust engineering controls + Prevents exposure, prevents complaints 45 Application Examples 46 23

Optical Particle Counter Clean Room Certification + FED-STD 209E +ISO 14644-1 Cleanroom Classification +Number of particles

jpg 47 Photometer Personal monitoring Mining + Organization has characterized site aerosol exposures and developed custom

24 Optical Particle Counter Clean Room Certification + FED-STD 209E +ISO Cleanroom Classification +Number of particles of various size per unit volume NASA over_environmental_monitoring_station.jpg 47 Photometer Personal monitoring Mining + Organization has characterized site aerosol exposures and developed custom calibration factors for silica. + Miners wear personal aerosol monitors on a regular basis to track silica exposure levels

25 Photometer Ambient smoke from forest fire + Handheld photometer used to measure ambient smoke levels for worker safety during regional forest fires Alberta, Canada 49 Photometer Dust storm & wild fire alerts Australian Outback 50 25

26 Photometer Fence Line Monitoring - Construction Meadowlands Stadium - New Jersey 51 Photometer Track Smoke Plumes + Protect Firefighters & Clean Up Crew Health + Quantify particle mass exposures to help EPA reporting Gulf of Mexico 52 26

27 Photometer Ambient urban pollution 53 Photometer Perimeter monitoring - Mining + Track wind, weather and aerosol concentration + Logging data for community awareness + Action level for dust suppression activities 54 27

Photometer Control Verification 2.5 2 Simulated Personal Exposure Data mg/m3 1.5 1 0.

silica on follow up 0 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00 12:30 Time 13:00 13:30 14:00 14:30

28 Photometer Control Verification Simulated Personal Exposure Data mg/m Foundry ventilation project + Engineering control investment (ventilation) + One person sampled high for silica on follow up 0 8:00 8:30 9:00 9:30 10:00 10:30 11:00 11:30 12:00 12:30 Time 13:00 13:30 14:00 14:30 15:00 15:30 16:00 55 Photometer Space Station Air Quality + TSI DustTrak used on International Space Station to monitor air quality 56 28

Respirator Fit Testing 8038 PortaCount Pro+ + Measure ultrafine particles leaking into the mask.

29 Condensation Particle Counter Fire Detection in Space Shuttle + TSI P-Trak ultrafine particle counter used on NASA Space Shuttles for smoke/fire detectors 57 Condensation Particle Counter Respirator Fit Testing 8038 PortaCount Pro+ + Measure ultrafine particles leaking into the mask. + Fit factor is calculated by difference between ambient aerosol particle counts and particle counts inside mask

Condensation Particle Counter IAQ complaints + Nurses on floor above

+ High concentration of ultrafine particles found coming through expansion

59 Condensation Particle Monitor Diesel Particulate Filter Testing + Solid

30 Condensation Particle Counter IAQ complaints + Nurses on floor above construction complaining of odors and headaches. + High concentration of ultrafine particles found coming through expansion joint. + Duct Tape applied to joint, complaints ceased. 59 Condensation Particle Monitor Diesel Particulate Filter Testing + Solid particle number concentration downstream of the Diesel Particulate Filter must be below 250,000 particles/cc + Swiss Regulation

31 Diesel Particulate Matter Most diesel exhaust particles are tiny enough to be inhaled deep into the lungs where they pose significant health risk. Workers Health and Safety Centre Federation of Ontario + Particulates Elemental carbon Organic compounds Sulfate Nitrate + Gases Carbon monoxide Carbon dioxide Sulfur Nitrogen oxides Aldehydes Benzene Polyaromatic hydrocarbons 61 Typical engine exhaust particle size distribution Kittelson, Journal of Aerosol Science,

32 MSHA DPM Exposure Limits Date Limit mg/m3 Constituent Interim / Final TC Interim (not enforced) TC Interim (enforced) EC Interim TC Interim TC Final TC = Total Carbon EC = Elemental Carbon Controlling Diesel Emissions in Underground Mining within an Evolving Regulatory Structure in Canada and the United States of America, S. McGinn, McGinn Integration Inc. 63 Reducing Particulate Matter Emitted by Engines + Very low particulate matter emission limits are challenging to measure accurately 64 32

33 Swiss Regulation Bi-annual testing of Non-Road Mobile Machinery + Solid particle number concentration downstream of the Diesel Particulate Filter must be below 250,000 particles/cc + Regulation promulgated January 1, 2015, enforcement begins April 1, Summary +Occupational health compliance based on Gravimetric Sampling +Real-Time Aerosol Monitors can help make faster decisions +Logged Data can display trends to help identify problems not measured with gravimetric sampling 66 33

34 Something to consider Ultrafine particles + high number concentration + very low mass Swiss Regulation Solid particle number concentration downstream of the Diesel Particulate Filter must be below 250,000 particles/cc + Future occupational health metrics? 67 Q & A Scott Norman, CIH, CSP Product Specialist TSI Incorporated Shoreview, MN (651) scott.norman@tsi.com 68 34

35 Appendix Beta Attenuation Monitor (BAM) The schematic of a beta attenuation monitor (BAM). 1 air inlet 2 cycling ribbon 3 and 4 beta radiation sources; D1 and D2 beta radiation detectors 5 air pump 6 air exhaust Source: Wikipedia 70 35

36 Beta Attenuation Monitor (BAM) + Beta Attenuation Monitor (BAM) This methodology collects particulate mass on a filter tape. Beta rays from a radiation source are attenuated according to a function of particulate mass. First the attenuation is measured through the blank filter tape to establish a baseline. Then the filter tape is exposed to ambient air flow to deposit particulate matter on the tape. Then beta attenuation is measured through the collected aerosol deposit and the effect due to particulate mass is calculated. The instrument advances the filter tape and repeats the process. 71 Tapered Element Oscillating Microbalance (TEOM) + Tapered Element Oscillating Microbalance (TEOM) This methodology continuously collects particles on a filter mounted on the tip of a glass element which oscillates in an applied electric filed. The glass element is hollow with the wider end fixed. Air is drawn through the filter and element. The oscillation frequency of the glass element is maintained based on the feedback signal from an optical sensor. The resonant frequency of the element decreases as mass accumulates on the filter, directly measuring inertial mass. Typical signal averaging period is 5 minutes

Piezoelectric Microbalance + Piezoelectric Microbalance This methodology deposits particles by inertial impaction or electrostatic precipitation onto the surface of a piezoelectric quartz crystal

The changing frequency of the sampling crystal is electronically compared to a clean reference crystal, generating a signal that is proportional to the collected mass.

37 Piezoelectric Microbalance + Piezoelectric Microbalance This methodology deposits particles by inertial impaction or electrostatic precipitation onto the surface of a piezoelectric quartz crystal disk. The natural resonant frequency of the crystal decreases as particle mass accumulates. The changing frequency of the sampling crystal is electronically compared to a clean reference crystal, generating a signal that is proportional to the collected mass. 73 Integrating Nephelometer + Integrating Nephelometer -This methodology focuses aerosol through an optics chamber where light (usually from a laser) is shined at the airstream containing the particles. An optical sensor measures the intensity of the light scattered by the particles. Aerosol mass is calculated based on the reflected intensity of a known calibration aerosol. TSI Model 3563 is an integrating NEPHELOMETER

Aerodynamic Particle Sizer (APS) Aerodynamic Particle Sizer This methodology uses parallel laser beams to measure the velocity lag of particles

75 Condensation Particle Counter (CPC) Condensation Nuclei Counter (aka Condensation Particle Counter) This methodology uses a condensing liquid

38 Aerodynamic Particle Sizer (APS) Aerodynamic Particle Sizer This methodology uses parallel laser beams to measure the velocity lag of particles suspended in accelerating air flows. The TSI Model 3321 APS uses this technology. 75 Condensation Particle Counter (CPC) Condensation Nuclei Counter (aka Condensation Particle Counter) This methodology uses a condensing liquid (alcohol or water) to grow the particle size large enough to be counted optically. These instrument s count numbers of particles, not mass concentration. The TSI PortaCountand P-Trakuse this technology

Differential Mobility Analyzer Spectrometer (DMS) Differential Mobility Analyzer- Spectrometer Particles are classified according to their mobility in an electric field, which is a function of their

39 Differential Mobility Analyzer Spectrometer (DMS) Differential Mobility Analyzer- Spectrometer Particles are classified according to their mobility in an electric field, which is a function of their size. A condensation nuclei counter then counts the population in a size bin. The TSI SMPS 3938 uses a Differential Mobility Analyzer to separate out particle size. 77 Optical Particle Counter (OPC) Optical Particle Counter (OPC) light scattered by individual particles traversing a light beam is detected at various angle. These signals are interpreted in terms of particle size via calibrations. The TSI Aerotrak Handheld Particle Counter 9303 and 9306 use this technology

DIRECT READING INSTRUMENTS FOR AEROSOLS

DIRECT READING INSTRUMENTS FOR AEROSOLS Avula Sreenath, Ph.D. TSI Inc. asreenath@tsi.com Florida Local Section of AIHA Fall Conference 2012 Jacksonville, FL Sept 21, 2012 Agenda 1. Learning Objectives