1 / 23

Continuous Measurements of Indoor-Outdoor Particulate PAH Concentrations in 7 Homes

14th Annual Conference of the International Society of Exposure Analysis, Philadelphia , PA. Paper No. W2A-04 October 21, 2004. Continuous Measurements of Indoor-Outdoor Particulate PAH Concentrations in 7 Homes with Application to the Indoor Mass-Balance Model and Prediction Error.

len
Download Presentation

Continuous Measurements of Indoor-Outdoor Particulate PAH Concentrations in 7 Homes

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. 14th Annual Conference of the International Society of Exposure Analysis, Philadelphia , PA Paper No. W2A-04 October 21, 2004 Continuous Measurements of Indoor-Outdoor Particulate PAH Concentrations in 7 Homes with Application to the Indoor Mass-Balance Model and Prediction Error

  2. AUTHORS Paul Switzer Don Rozenberg Wayne Ott Neil Klepeis Department of Statistics Stanford University CONTRIBUTORS Mary Rozenberg Pamela Shreeve Laure Yadon George Angus Karen Johnson Lee Langan Peggy McClure

  3. Indoor-Outdoor Model • Derived from Mass-Balance Equation • Theoretical Basis, Exact • Equally-Spaced Time Steps • Outdoor Concentrations as Input • Only Two Parameters Required • Predicted Indoor Concentration Compared with Measured Indoor Concentration

  4. Recursive Indoor-Outdoor Model for PM

  5. Modeling Approach(Piecewise-Constant Inputs and Piecewise-Exponential Outputs)

  6. Persistence Parameter  for Different Combinations of a and k for 1-min Time Step

  7. Indoor Persistence Parameter  versus (a + k) for 1-min and 5-min Time Steps

  8. METHOD • Measure Continuous Outdoor and Indoor Total Particulate PAH (< 1 m) • Combustion Sources, Little Humidity Effect • Occupied, Nonsmoking Homes • Find Optimum Values of ,  • Compare Predicted Indoor Concentration with Measured Indoor Concentration • For , , Calculate Ranges of a, k, and p

  9. Table 1 aCentrally located test home; b1-min averages; cArea of a single level.

  10. Outdoor and Indoor PPAH, New Year’s Day San Francisco House No. 2

  11. Arbitrary Parameters Optimal Parameters

  12. Error Surface for Indoor Model Prediction Versus Indoor Measurement at San Francisco House No. 2 ( 1-min step time for 3.5 days)

  13. Error Surface for Data at Redwood City House1994 - 1995 (17.5 days, 5-min time step)

  14. Error Surface Slices at Fixed Alpha Values

  15. Indoor Predicted vs. Indoor Measuredat Redwood City House, 17-1/2 Days

  16. MeasuredOutdoor, MeasuredIndoorPPAH Predicted Indoor,Measured Indoor PPAH

  17. Table 2

  18. Table 3

  19. Table 4

  20. DISCUSSION • Predicting indoor particle concentrations of • ambient origin using the mass balance model • requires only two parameters,  and . • Using three parameters a, k, and p in the indoor • mass balance model is algebraically redundant.

  21. CONCLUSIONS • Continuous Indoor-Outdoor PPAH Measurements in 7 Occupied Homes • Field Study Covered 10 Years • Indoor Model-Predicted Agreed Well with Indoor Measured at All Homes • Fireplaces and Wood Burning were the Major Sources of Ambient Particulate PAH • Motor Vehicles were a Minor Source • Indoor Model with 3 Parameters (a, k, and p) is Over-specified

More Related