Whittaker Powerpoint June 08


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Presentation to Columbia SC IAQA chapter about the uses for laser particle counting devices in assessing indoor air quality.

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  • Penicillium, aspergillus and trichoderma spores fall into the 2.5-micron size
  • Living room area of the crawl is the top picture
  • Kitchen area of the crawl is the top picture
  • Living room area of the crawl is the top picture
  • Total counts from 21 projects where particle counts (PC), spore traps (SpT) and airborne cultures (Cult) were collected. The graph on the left indicates the counts for the initial, or pre-remediation assessment. The graph on the right indicates the counts for the post-remediation verification (PRV) assessment.
  • Average counts for the 21 projects. This data is more meaningful as it displays numbers that many IAQ professionals will accept as familiar. Particle counts are generally higher than spore counts; particle counts are higher than spore counts in 15 of 21 pre-remediation readings and in 19 of 21 post-remediation readings.
  • Raw data from the 21 projects illustrated in the previous two slides. On average, 66% of the particles collected in the 1.0 to 10.0-micron sizes prior to remediation were fungal spores and 43% of particles collected post-remediation were fungal spores.
  • These slides are optional (time permitting)
  • Chart shows maximum concentration limits for particles equal to and larger than the sizes shown
  • Four good written resources for people interested in learning more about the role of particle counters in an IAQ investigation
  • Whittaker Powerpoint June 08

    1. 1. Applications of the Opticle Particle Counter in an IAQ Assessment Columbia SC Chapter IAQA Workshop June 26, 2008 Presented by: Craig Whittaker, CIE, Ph.D. Environmental Solutions Group
    2. 2. Brief History of the Particle Counter <ul><li>Parallels the development of the personal computer </li></ul><ul><li>First developed in the 50s to monitor dust in manufacturing </li></ul>
    3. 3. <ul><li>Evolved into a tool for assessing clean rooms </li></ul><ul><li>Greatest design advances made in last few years </li></ul>
    4. 4. <ul><li>The IAQ professional now has several options for small, powerful and intuitive devices that offer real-time data logging & other features </li></ul>
    5. 5. <ul><li>Most airborne particles are either biological contaminants, gases or dust </li></ul><ul><li>Handheld particle counters today are well-equipped for measuring airborne biological contamination </li></ul>Current Technology
    6. 6. <ul><li>Biological contaminants include: </li></ul><ul><li>Mold </li></ul><ul><li>Dust mites </li></ul><ul><li>Viruses </li></ul><ul><li>Animal dander </li></ul><ul><li>Bacteria </li></ul><ul><li>Pollen </li></ul><ul><li>Skin fragments </li></ul><ul><li>Insect parts </li></ul>
    7. 8. Recent Studies on the Health Effects of Fine Airborne Particles European study found that fine particles that are inhaled can affect the blood vessels, leading to an increased risk of heart disease - American Journal of Respiratory and Critical Care Medicine Children with asthma had significantly decreased lung function following exposure to indoor air pollution that included fine airborne particles - National Institute of Allergy and Infectious Diseases
    8. 9. How Does the Particle Counter Work? <ul><li>Counts particles that block a beam of light reflecting onto a screen </li></ul>
    9. 10. The three components of a particle counter: 1) airflow system 2) optical system 3) electronics
    10. 11. The Airflow System <ul><li>Includes an isokinetic probe, air chamber and pump </li></ul><ul><li>Its job is to capture a sample of moving air at the same velocity it is moving, allowing a normalized count </li></ul>
    11. 12. The Optical System <ul><li>Includes a high-grade laser, optical measuring components and a detection surface (screen) </li></ul><ul><li>Its job is to measure the scattered light against the screen </li></ul>
    12. 13. The Electronics <ul><li>Includes computerized amplification and </li></ul><ul><li>counting circuitry </li></ul><ul><li>Its job is to amplify the low level signals from the detector surface and convert each scattered light pulse to a number representing its corresponding size </li></ul>
    13. 15. Tabletop vs. Portable Unit <ul><li>Tabletop unit has a larger pump and can attach to multiple sensors throughout an area for continuous monitoring of clean rooms </li></ul><ul><li>Portable unit is designed for point-of-use measurements in critical locations to include clean rooms, medical facilities and HVAC systems analysis in commercial & residential buildings </li></ul>
    14. 16. <ul><li>One of the most useful aspects of the portable unit is the ability to track contamination - everything from fine dust to biologicals - to the source </li></ul>
    15. 17. <ul><li>One of the most common applications of the portable unit is for measuring the efficiency of filtration systems </li></ul>
    16. 18. Limitations of the Laser Particle Counter <ul><li>Refracted light varies due to differences in particle shape & shininess </li></ul><ul><li>Particles are not always evenly distributed throughout a room </li></ul><ul><li>The electronics employ a bell-curve (Gaussian) distribution method of categorizing particle sizes </li></ul>
    17. 19. Guidelines for Use <ul><li>Store unit at room temperature in a </li></ul><ul><li>vibration-free environment </li></ul><ul><li>Keep unit clean per manufacturer’s instructions </li></ul><ul><li>Stay clear of electrical equipment while collecting readings </li></ul><ul><li>Consider keeping a log of preventive maintenance, recalibrations and any unusual performance </li></ul>
    18. 20. Application: Trend Analysis <ul><li>Noting gradual or sudden changes in airborne contamination when an HVAC system is powered on/off 1 </li></ul><ul><li>Establish baseline readings prior to a process that may change the indoor air environment </li></ul><ul><li>Monitoring filter efficiency by sampling air immediately before entering & after entering the filter </li></ul><ul><li>1 NADCA’s ACR 2006 contains particle profiling procedures for HVAC systems </li></ul>
    19. 21. <ul><li>The single most important advantage of the handheld particle counter is the ability to conveniently collect multiple readings in an area to generate a statistically valid sample based on the average particle counts for the area. </li></ul>
    20. 26. Case Study #1: Outpatient Surgical Center <ul><li>Two operating rooms and sterilization and surgical preparatory rooms flooded with clean water over a weekend. Water soaked floors and drywall. </li></ul><ul><li>Our firm arrived immediately after standing water was extracted to collect baseline (first-response) airborne particle readings prior to installation of HEPA air scrubbers. </li></ul>
    21. 27. <ul><li>Safety was of primary importance to the client but speed of remediation was also crucial. The remediation and reconstruction had to be complete and post-remediation verification obtained in only 48 hours </li></ul><ul><li>Handheld particle counters were used extensively to monitor the effectiveness of air scrubbers </li></ul>
    22. 28. <ul><li>Particle counts were recorded at entering and exiting points of twelve air scrubbers </li></ul><ul><li>Scrubber positions were adjusted frequently to address ‘hot spots’ where counts had spiked </li></ul>
    23. 29. <ul><li>Every phase of the project was guided in part by the particle readings </li></ul><ul><li>The remediation was completed ahead of schedule and particle counts were excellent. All that remained to be installed was the new flooring. </li></ul>
    24. 30. <ul><li>The ‘sterile’ vinyl arrived in the back of a filthy truck </li></ul><ul><li>Particle counts jumped nearly 7000% in the operating rooms upon bringing the vinyl into the rooms </li></ul>
    25. 31. <ul><li>The floors were finished at midnight with the rooms scheduled to open at 7:00 am. </li></ul><ul><li>We logged airborne particle counts until 5:30 am; counts were low enough to indicate a successful clearance </li></ul>
    26. 32. <ul><li>Spore counts were collected for lab analysis in one hand while re-checking particle counts in the other hand </li></ul>
    27. 33. <ul><li>Rush analysis by a local lab confirmed </li></ul><ul><li>that no fungal spores were present </li></ul><ul><li>in the operating suite. </li></ul><ul><li>Surgeries were performed on schedule and the client was relieved </li></ul>
    28. 34. Case Study #2: Physician’s Residence <ul><li>A medical doctor who recently purchased a 100-year-old home on the NC coast had experienced flu-like symptoms since moving in two months ago </li></ul><ul><li>His wife and child have no symptoms, but they sometimes noticed a musty odor on the main level </li></ul><ul><li>A visual assessment yielded no moist building materials or fungal growth inside the home </li></ul>
    29. 35. <ul><li>Airborne particle counts were abnormally high in the 2.5- µ m classification in the kitchen. After ruling out food items as the source, we collected a particle reading in a base cabinet and found the 2.5 - µ m count to be 700% higher than the average count for that size particle elsewhere in the house </li></ul>
    30. 37. <ul><li>The culprit appeared to be gold-colored material on an exterior plaster wall in a base cabinet where cooking items were stored. We removed several items to expose the material for sampling & for taking this picture. </li></ul>
    31. 38. <ul><li>Lab analysis indicated an elevated count of 2320 aspergillus/penicillium spores/m 3 in the total spore count. An air culture indicated a count of 320 cfu/m 3 of aspergillus. </li></ul><ul><li>The physician/homeowner was subsequently tested and found to have a fungal infection in his digestive tract. Remediation and antibiotics have resolved his medical issue. </li></ul>
    32. 39. Case Study #3: Office Building <ul><li>An employee at a call center that had experienced a water leak from the HVAC system one year ago was taken to the hospital after cleaning under her desk. She developed a severe rash on her arms & was having trouble breathing. </li></ul><ul><li>The employee told us that the carpet under her desk remained wet for a few days following the leak incident of a year ago </li></ul>
    33. 40. <ul><li>Particle counts were collected in thirty locations throughout the 10,000 SF building. Ambient readings and readings at air supplies were collected. </li></ul><ul><li>Particle counts were normal for the building in all areas except near the affected employee’s desk, averaging 1167 count in the 1.0 to 10.0- µ m classifications. Readings near the desk averaged 1483. </li></ul>
    34. 41. <ul><li>After slightly agitating the carpet under the employee’s desk, particle readings jumped over 300% from 1483 to 4619 in the 1.0 - 10.0 µ m classifications. </li></ul>
    35. 42. <ul><li>Lab analysis indicated an elevated presence of aspergillus/penicillium in a sample of the carpet and an elevated count of 1320 aspergillus/penicillium spores/m 3 in the total spore count collection from under the desk. An air culture indicated a count of 271 cfu/m 3 of penicillium. </li></ul><ul><li>The employee is allergic to penicillin and her doctor believes that her immune system had a reaction to the spores released from the carpet during vacuuming. </li></ul><ul><li>The carpet was replaced and the area cleaned and the employee has had no further issues. </li></ul>
    36. 43. Case Study #4: Three Crawl Spaces <ul><li>Examines the relationship between room particulate counts in residences with crawl spaces with some areas of visible fungal contamination. </li></ul><ul><li>Question: is there a correlation between elevated airborne particle counts in an area with no visible contamination and an adjacent but hidden area with visible contamination such as in a crawl space? </li></ul>
    37. 47. Conclusion <ul><ul><li>Based on somewhat limited data, the opticle particle counter appears to provide the IAQ investigator who is assessing an apparently clean area with information that relates to fungal contamination in an adjacent but hidden contaminated area. </li></ul></ul>
    38. 48. Data Set from 21 Locations <ul><li>A collection of pre- and post-remedial readings from residential, office and medical buildings </li></ul><ul><li>Criteria for inclusion: </li></ul><ul><li>Our firm performed the assessments </li></ul><ul><li>The identical calibrated equipment was used for data collection </li></ul><ul><li>Lab analysis was performed by the same lab </li></ul><ul><li>Data is less than one year old </li></ul>
    39. 52. Conclusion <ul><ul><li>The opticle particle counter provides the IAQ investigator with a convenient means to gather a substantial amount of reliable, real-time data relating to air quality. It is a valuable addition to the IAQ investigator’s toolkit. </li></ul></ul><ul><ul><li>More research is needed, however, to determine how the data is to be interpreted. </li></ul></ul>
    40. 53. Additional Research Areas What role does the environmental condition play? Dampness Barometric Pressure Building Pressurization Temperature
    41. 54. Selection of a Particle Counter <ul><li>Define the intended use of the device - will you be assessing cleanrooms or ‘dirty’ areas (or both?) </li></ul><ul><li>Decide on the features you require - will you be storing large amounts of data, assessing for certain particle sizes, printing readings on site, or downloading data into a computer? </li></ul><ul><li>How easy is the unit to use? Can it survive a fall or extreme conditions? Does it have a touch-screen interface? Can it record temperature & humidity readings in addition to particle sizes and mass concentration? </li></ul><ul><li>You may want to try renting a unit prior to making a purchase so you don’t make a mistake (these devices start around $2000) </li></ul>
    42. 55. ISO 14664-1 Cleanroom Standards 293,000 29,300 2,930 293 29 5 µ m 8,320,000 35,200,000 ISO 9 832,000 3,520,000 ISO 8 83,200 352,000 ISO 7 8,320 35,200 102,000 237,000 1,000,000 ISO 6 832 3.520 10,020 23,700 100,000 ISO 5 83 352 1,020 2,370 10,000 ISO 4 8 35 102 237 1,000 ISO 3 4 10 24 100 ISO 2 2 10 ISO 1 1 µ m 0.5 µ m 0.3 µ m 0.2 µ m 0.1 µ m
    43. 56. Selected Resources <ul><li>American Industrial Hygiene Association, Assessment, Remediation, and Post-Remediation Verification of Mold in Buildings (2004) </li></ul><ul><li>National Air Duct Cleaners Association, Assessment, Cleaning and Restoration of HVAC Systems (ACR 2006) </li></ul><ul><li>Hollace S. Bailey, Fungal Contamination: A Manual for Investigation, Remediation and Control (2005) </li></ul><ul><li>Particle Measuring Systems, Counting Efficiency and Resolution in Optical Particle Counters (2007) </li></ul>
    44. 57. Authors <ul><li>Craig Whittaker , Ph.D., CIE </li></ul><ul><li>Environmental Solutions Group </li></ul><ul><li>Steven Armstrong , M.S., P.G. </li></ul><ul><li>Environmental Solutions Group </li></ul>
    45. 58. Thank you for attending! <ul><li>Are there any questions? </li></ul>