December 1996 EPA 747-R-96-011 FINAL REPORT ADJUSTMENTS TO THE HUD NATIONAL SURVEY DUST DATA FOR SECTION 403 ANALYSES Prepared By Battelle Memorial Institute and Midwest Research Institute for Technical Programs Branch Chemical Management Division Office of Pollution Prevention and Toxics Office of Prevention, Pesticides, and Toxic Substances U.S. Environmental Protection Agency ------- Washington, DC 20460 ------- DISCLAIMER The material in this document has been subject to Agency technical and policy review and approved for publication as an EPA report. Mention of trade names, products, or services does not convey, and should not be interpreted as conveying, official EPA approval, endorsement, or recommendation. ------- AUTHORS AND CONTRIBUTORS This study was funded and managed by the U.S. Environmental Protection Agency. The study was conducted by Battelle Memorial Institute under contract to the U.S. Environmental Protection Agency. Midwest Research Institute was issued a subcontract by Battelle to perform the laboratory experiments necessary for the study. Each organization's responsibilities are listed below. Battelle Memorial Institute (Battelle) Battelle was responsible for designing and conducting the study, managing the work performed by Midwest Research Institute, performing statistical analyses on the study data, developing the conclusions and recommendations derived from the analyses, applying correction factors to the HUD National Survey data, and writing the final report. Midwest Research Institute (MRI) MRI was responsible for designing and conducting the laboratory experiments performed as part of the study, performing statistical analyses on the study data, and writing Appendix A of the final report. U.S. Environmental Protection Agency (EPA) EPA was responsible for managing the study, providing guidance on the objectives for the study and report, contributing to the development of conclusions and recommendations, and coordinating the EPA and peer reviews of the draft report. The work was done under the direction of Janet Remmers and Bradley Schultz. The EPA Project Officer was Sineta Wooten. ------- TABLE OF CONTENTS Page EXECUTIVE SUMMARY iii 1.0 INTRODUCTION 1 1.1 PEER REVIEW 1 2.0 EFFECT OF LOW TAP WEIGHTS ON DUST-LEAD CONCENTRATIONS 2 2.1 Why Dust-Lead Concentrations May Be Biased 3 2.2 Statistical Assessment of Low Tap Weight Samples 4 2.3 Laboratory Assessment of Low Tap Weight Samples 13 2.4 Correcting the Bias in Dust-Lead Concentration 14 3.0 WIPE SAMPLES IN HUD NATIONAL SURVEY 16 4.0 DISCUSSION, SUMMARY, AND CONCLUSIONS 24 5.0 REFERENCES 28 APPENDIX A A-1 APPENDIX B B-1 LIST OF TABLES Table 1. Floor Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 6 Table 2. Window Sill Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 7 Table 3. Window Trough Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 8 Table 4. Floor, Window Sill, and Window Trough Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight For the 284 Privately-Owned Houses in the HUD National Survey 9 Table 5. Results of Outlier Analysis 12 Table 6. Test Matrix for Laboratory Experiments 14 Table 7. Floor Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey ... 17 Table 8. Window Sill Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 18 Table 9. Window Trough Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 19 Table 10. Floor, Window Sill, and Window Trough Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey 20 Table 11. Distribution of Wipe Samples Taken in the HUD National Survey 21 ------- TABLE OF CONTENTS (continued) LIST OF FIGURES Figure 1. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weight Equal to 0.1 mg 10 Figure 2. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than 0.1 mg and Less than 5 mg 10 Figure 3. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 5 mg and Less than 10 mg 11 Figure 4. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal 10 mg 11 Figure 5. Ratio of Total Weight of Dust Divided by Tap Weight Plotted Against Tap Weight and Overlaid with Fitted Regression Model 15 Figure 6. Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weight Equal to 0.1 mg 22 Figure 7. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than 0.1 mg and Less than 5 mg 22 Figure 8. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 5 mg and less than 10 mg. ... 23 Figure 9. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 10 mg 23 Figure 10. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for all Samples 24 ------- EXECUTIVE SUMMARY The Risk Assessment, Economic Analyses, and Regulatory Impact Analyses being conducted to support the rulemaking for Section 403 of Title IV of the Toxic Substance Control Act all require information on environmental-lead levels in the national housing stock. The HUD National Survey is the primary source of data for these environmental-lead levels. During the course of the rulemaking, an issue was raised concerning the quality of the dust samples collected in the HUD National Survey: in particular, the effect of low tap weights on measured dust-lead concentrations. Most of the dust samples in the HUD National Survey were collected using the Blue Nozzle vacuum. The Blue Nozzle vacuum collects dust in a plastic cassette containing a piece of cellulose fiber filter paper to capture the dust. In the HUD National Survey, only the weight of the dust that was tapped out of the cassette, referred to herein as tap weight, was determined. However, subsequent chemical analyses determined the amount of lead for both the dust tapped out of the cassette and residual dust in the filter cassette. Dust-lead concentration was then computed as the total amount of lead divided by the tap weight. Reported dust-lead concentrations will be biased if the tap weight substantially underestimates the combined weight of the dust tapped out of the cassette and residual dust remaining in the filter cassette. This bias, if present, will generally result in higher lead concentrations for samples with lower tap weights compared to samples with higher tap weights. A statistical analysis of the dust sample data collected from the 284 privately-owned residences in the HUD National Survey was performed to investigate possible differences in dust- lead concentrations as a function of the tap weight. Descriptive analyses of the lead concentrations indicated that the dust-lead concentrations reported in the HUD National Survey increased with decreased tap weight. The trend may be due to a bias. Laboratory experiments were conducted to generate a database for understanding and addressing the possible bias in dust-lead concentration computed via tap weight in the HUD National Survey. A regression model, developed for correcting the bias, was fitted to the laboratory data. Dust-lead concentrations reported in the HUD National Survey were then adjusted using correction factors predicted by the regression model. The regression model in ------- removed the trend of dust-lead concentrations increasing with decreasing tap weight. For purposes of analyses conducted to support Section 403, the correction was applied only to dust samples with tap weights greater than or equal to 0.7 mg. This limitation was required because tap weights in the dataset used to develop the regression model were all greater than or equal to 0.7 mg. Therefore, the correction factor predicted by the regression model may over-correct dust-lead concentrations for samples with tap weights less than 0.7 mg. For the purposes of analyses conducted to support Section 403, dust-lead concentrations of dust samples with tap weights less than 0.7 mg were excluded from the analysis of dust-lead concentrations. This decision applied only to the lead concentrations and not the lead loadings of these samples. IV ------- 1.0 INTRODUCTION Section 403 of Title IV of the Toxic Substances Control Act (TSCA), as amended in Title X, the Residential Lead-Based Paint Hazard Reduction Act, will set standards (condition and location of lead-based paint, ranges of lead in dust and soil) against which to compare a residential environment when evaluating the presence and magnitude of lead-based paint hazards. The Risk Assessment, Economic Analyses, and Regulatory Impact Analyses being conducted for this rule all require information on environmental-lead levels in the national housing stock. The HUD National Survey [1, 2] is the primary source of data for these environmental-lead levels. Conducted in 1989-1990, the HUD National Survey collected data on lead levels in paint, dust, and soil from 284 privately-owned and 97 publicly-owned occupied housing units. The units were selected via a statistically-based sampling design to represent the national housing stock built prior to 1980. During the course of the analyses to support Section 403 rulemaking, an issue was raised concerning the quality of the dust samples collected in the HUD National Survey: in particular, the effect of low tap weights on measured dust-lead concentrations. In addition, it was noted that a few dust samples were collected using wipes instead of the planned vacuum method. This report documents an assessment of these two items. The assessment involved only dust samples collected from entryways, dry rooms, and wet rooms in the 284 privately-owned residences sampled in the HUD National Survey. Section 2 discusses the effect of low tap weights on lead concentrations for dust samples collected in the HUD National Survey. The identification of dust samples collected with wipes is addressed in Section 3. An evaluation of these two items on the Section 403 Risk Assessment and recommendations for resolving them are presented in Section 4. 1.1 PEER REVIEW The technical report on this study was reviewed independently by members of a peer review panel. The majority of comments received were either informational and required no changes, or were editorial in nature. The following paragraphs summarize the remainder of the comments and how they were addressed. ------- One reviewer suggested that the reversed weight ratio (the weight of the tapped-out dust over the weight of total dust) should be used to correct the bias rather than weight ratio model used in this report. After investigating this possibility, it was decided that over the range of tap weights in the HUD National Survey data, no substantial differences in correction factors would result from using the reversed weight ratio. For this reason, the form of the model presented in this report was not changed. Another reviewer pointed out that the data point in the laboratory study which was identified as an outlier based on visual inspection alone could not be considered an outlier without a quantitative justification. After reviewing the laboratory data, it was determined that all of the data should be included in the model fitting. As a result, a new regression model was fitted to the laboratory data and the revised correction factors were applied to the HUD National Survey dust data. This revision was relatively minor, with the average percent change between the original adjustment to the data and the new adjustment equaling 1.6 percent. EPA has established a public record for the peer review under administrative record 168. The record is available in the TCSA Nonconfidential Information Center, which is open from noon to 4 pm Monday through Friday, except legal holidays. The TCSA Nonconfidential Information Center is located in Room NE-B607, Northeast Mall, 401 M Street SW, Washington, D.C. 2.0 EFFECT OF LOW TAP WEIGHTS ON DUST-LEAD CONCENTRATIONS Section 2.1 discusses why dust-lead concentrations measured in the HUD National Survey may be biased. Furthermore, it is indicated there that the bias is likely to increase with decreasing tap weight and that the bias may be expressed as a function of the ratio of total dust weight to tap weight. Descriptive analyses presented in Section 2.2 show that the dust-lead concentrations reported in the HUD National Survey increased with decreased tap weight. The trend may be due to a bias. Laboratory experiments were conducted to measure weight of residual dust in filter cassettes, tap weight, total dust weight, and ratio of total dust weight to tap weight for dust samples collected via the Blue Nozzle vacuum. The experiments, summarized in Section 2.3, ------- provided a database for understanding and addressing the bias in dust-lead concentration computed via tap weight in the HUD National Survey. A regression model, developed for correcting the bias, was fitted to the laboratory data. In Section 2.4, the regression model is applied to the dust-lead concentrations collected in the HUD National Survey. Furthermore, it is shown in Section 2.4 that the regression model removes the trend of dust-lead concentrations increasing with decreased tap weight. 2.1 WHY DUST-LEAD CONCENTRATIONS MAY BE BIASED Dust samples were collected from interior window sills, window troughs, and floors in the HUD National Survey using the Blue Nozzle vacuum device. The Blue Nozzle vacuum collects dust in a plastic cassette containing a piece of cellulose fiber filter paper to capture the dust [3]. In the HUD National Survey, the filter cassettes were not preweighed before sampling, and only the weight of the dust that was tapped out of the cassette, referred to herein as tap weight, was determined. However, subsequent chemical analyses on each sample determined the amount of lead for both the dust tapped out of the cassette and residual dust in the filter cassette, combined. Dust-lead concentration was then computed as the total amount of lead divided by the tap weight. It is believed that some dust may have remained in the filter cassette, in which case the dust-lead concentrations reported in the HUD National Survey may be biased. Dust-lead concentration is defined as weight of lead in sampled dust divided by weight of sampled dust. Dust-lead concentrations reported in the HUD National Survey will be biased if the tap weight substantially underestimates the combined weight of the dust tapped out of the filter cassette and residual dust remaining on the filter cassette. The dust-lead concentration reported in the HUD National Survey is equal to: (jig of Pb on filter cassette) + (jig of Pb for tapped-out dust) (g of tapped-out dust) ------- instead of what should have been measured and reported: (|ig of Pb on Filter cassette) + (|ig of Pb for tapped-out dust) (g of dust on filter cassette) + (g of tapped-out dust) The ratio of the two terms is (g of dust on filter cassette) + (g of tapped-out dust) _ total dust weight (g of tapped-out dust) tap weight where total dust weight is the total weight of the dust tapped out of the filter cassette and residual dust remaining in the filter cassette. Therefore, the bias in the reported dust-lead concentrations is a function of the ratio of the total dust weight to the tap weight. Because the weight of the residual dust in the filter cassette is likely to comprise a larger percentage of the total dust weight for low tap weight samples, the bias is expected to increase with decreased tap weight. This bias in dust-lead concentration, if present in the HUD National Survey, would generally result in higher dust-lead concentrations for samples with lower tap weights compared to samples with higher tap weights. 2.2 STATISTICAL ASSESSMENT OF LOW TAP WEIGHT SAMPLES A statistical analysis of the dust sample data collected from the 284 private houses was performed to investigate possible differences in dust-lead concentrations as a function of the tap weight. Only window and floor samples from dry-rooms, wet-rooms and entranceways were included in the analysis. All samples collected from common areas in the HUD National Survey were excluded since these samples will not be included in analyses supporting Section 403 rulemaking. To evaluate the impact of low tap weight on dust-lead concentrations, dust-lead concentrations were examined for nine ranges of tap weight spanning from 0.1 mg to greater than 25 mg. The first tap weight range, tap weight of 0.1 mg, was called out separately because 0.1 mg may represent the limit of detection for the gravimetric analysis. Conversations with laboratory personnel providing the basis for this reasoning are discussed in Section 4.0. ------- Furthermore, dust-lead loadings and/or dust-lead concentrations were missing for 599 of the 718 samples with a tap weight of 0.1 mg. Table 1 presents summary statistics for the dust-lead concentrations and dust-lead loadings for floor dust samples for each of the nine ranges of tap weight and all floor dust samples regardless of tap weight. The number of these samples with a nonmissing dust-lead concentration, the geometric mean, geometric standard deviation, and range of the dust-lead concentrations for the floor dust samples are shown in columns two to six. Column seven provides the number of floor dust samples with a dust-lead concentration greater than 1000 jig/g. The number of non-missing dust-lead loadings, the geometric mean, and geometric standard deviation for the dust-lead loadings of the floor dust samples are presented in the last three columns of the table. Tables 2 and 3 present similar results for window sill and window trough samples, respectively. Results calculated across floor, window sill, and window trough samples are presented in Table 4. An inverse relationship between dust-lead concentration and tap weight is apparent in Table 1; dust-lead concentration decreased with increased tap weight. A similar relation is seen in Table 2 for window sill dust-lead concentration. As shown in Table 3, there is no apparent trend between dust-lead concentration and tap weight for samples collected from window troughs. However, the limited sample size may have made it impossible to detect any trend. Only 25 out of the 149 dust samples collected from window troughs had tap weights less than 10 mg, and window trough dust-lead concentrations tend to be more variable than those collected from floors and window sills. Floor dust-lead concentrations are plotted against tap weights in Figures 1 to 4, with each of the plots corresponding to one of four tap weight classifications. To better show the data, the y-axis was truncated at 15,000 jig/g and floor dust samples with dust-lead concentrations greater than 15,000 jig/g were omitted from each of the plots. A total of four samples were excluded; three in Figure 2 and one in Figure 3. Three of the samples had dust-lead concentrations greater than 100,000 |ig/g. Figure 1 shows dust-lead concentrations for the 0.1 mg tap weight samples, which are all greater than 4000 jig/g. As stated above, there is some concern about the validity of these 0.1 mg tap weight samples. Although the trend of increased dust-lead concentration with decreased tap weight is quite visible in Figure 2, the relationship is not obvious in Figures 3 and 4. ------- Table 1. Floor Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to<1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 10 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 5 37 30 35 35 15 118 137 402 814 Geometric Mean 6540 1290 752 427 310 327 280 210 190 256 Geometric Standard Deviation 1.5 3.4 4.7 2.8 5.4 3.1 3.1 3.3 4.2 4.2 Minimum 4660 41.4 75.0 24.9 3.45 43.1 24.5 1.13 0.0500 0.0500 Maximum 13000 18600 355000 4330 114000 3770 133000 3760 11300 355000 Number >1000 5 23 12 5 7 3 11 12 42 120 Dust-Lead Loading (ug/ft2) Number 26 35 30 35 35 15 117 137 402 832 Geometric Mean 0.115 0.139 0.270 0.256 0.272 0.377 0.500 0.850 4.36 1.30 Geometric Standard Deviation 3.6 4.1 4.6 2.9 5.4 3.2 3.2 3.3 4.7 6.6 ------- Table 2. Window Sill Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to<1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 10 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 27 41 26 19 13 13 51 44 105 339 Geometric Mean 3800 2030 1570 989 940 451 658 476 665 911 Geometric Standard Deviation 4.7 8.9 5.4 3.3 4.1 4.3 5.6 4.7 6.7 6.4 Minimum 124 15.5 37.7 55.9 156 42.9 3.06 1.74 0.785 0.785 Maximum 55900 5850000 104000 7500 9640 4530 96500 9650 102000 5850000 Number >1000 22 25 16 9 7 4 20 14 41 158 Dust-Lead Loading (ug/ft2) Number 79 41 26 19 13 13 51 44 106 392 Geometric Mean 0.317 1.03 2.15 1.97 3.93 1.87 3.92 4.99 44.8 3.70 Geometric Standard Deviation 5.3 7.7 6.1 4.5 5.1 4.6 6.0 6.2 5.5 12 ------- Table 3. Window Trough Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately- Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to<1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 10 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 5 3 0 1 4 3 9 18 106 149 Geometric Mean 10700 1830 122 2450 4780 4920 1680 1770 2010 Geometric Standard Deviation 8.5 4.7 3.4 2.4 3.4 9.8 6.4 6.6 Minimum 2430 305 122 473 2820 1010 33.7 5.17 5.17 Maximum 457000 4980 122 7800 13300 63100 83600 109000 457000 Number >1000 5 2 0 3 3 9 10 69 101 Dust-Lead Loading (ug/ft2) Number 14 3 0 1 4 3 9 18 106 158 Geometric Mean 0.546 0.703 0.366 9.88 25.7 34.5 33.3 243 76.6 Geometric Standard Deviation 6.5 6.4 3.0 2.2 3.9 9.6 6.2 15 ------- Table 4. Floor, Window Sill, and Window Trough Dust-Lead Concentrations and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to<1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 10 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 37 81 56 55 52 31 178 199 613 1302 Geometric Mean 4700 1640 1060 558 480 485 413 303 346 451 Geometric Standard Deviation 4.7 5.9 5.2 3.2 5.5 4.3 4.5 4.7 6.2 5.9 Minimum 124 15.5 37.7 24.9 3.45 42.9 3.06 1.13 0.0500 0.0520 Maximum 457000 5850000 355000 7500 114000 13300 133000 83600 109000 5850000 Number >1000 32 50 28 14 17 10 40 36 152 379 Dust-Lead Loading (ug/ft2) Number 119 79 56 55 52 31 177 199 614 1382 Geometric Mean 0.271 0.418 0.707 0.522 0.700 1.11 1.12 1.75 13.0 2.78 Geometric Standard Deviation 5.3 7.5 7.1 4.7 8.3 6.1 6.3 6.5 9.7 12 ------- HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 15000 - 14OOO -_ 13OOO -_ 12000 -_ 11OOO -_ 10OOO -_ 9000 -_ 8OOO -_ 7000 -_ 6OOO -_ 5OOO -_ 4000 -_ 3OOO -_ 2OOO r 1000 -_ O - 0.1 Dust Tap Weight (mg) Figure 1. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weight Equal to 0.1 mg. HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 15OOO - 14OOO -_ 13000 -_ 12OOO -_ 11000 -_ 10OOO -_ 9OOO -_ 8000 -_ 7OOO -_ 6OOO -_ 5000 -_ 4OOO -_ 3000 -_ 2OOO -_ 1OOO 7 O - A A A A A * 2 3 Dust Tap Weight (mg) Figure 2. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than 0.1 mg and Less than 5 mg. Two Samples with Dust-Lead Concentrations Greater than 100,000 ug/g and One Sample with Dust-Lead Concentration Approximately 20,000 ug/g are not Shown in the Plot. 10 ------- HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 15000 - 14OOO 13000 12000 -_ 11000 -_ 10000 H 9000 -_ 8000 7000 -_ 6OOO 5000^ 4OOO -_ 3000^ 2000 H 1000 -_ 0- A A A A A 7 8 Dust Tap Weight (mg) Figure 3. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 5 mg and Less than 10 mg. One Sample with a Dust-Lead Concentration Greater than 100,000 ug/g is not Shown in the Plot. 15000 14000 13000 12000 11OOO 10000 9000 8000 7000 6OOO 5000 4OOO 3000 2000 1000 0 HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 1000 2000 3000 Dust Tap Weight (mg) 4000 5000 Figure 4. Floor Dust-Lead Concentration Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal 10 mg. 11 ------- Additional analyses were conducted to determine if any of the floor dust-lead concentrations for the 284 privately-owned homes in the HUD National Survey were statistical outliers. An outlier is a data point that is abnormally large or small in value. Because large and small are relative terms, externally deleted studentized residuals were employed to determine how large or small each dust-lead concentration was relative to the mean dust-lead concentration for the floor samples in the same tap weight category for four categories: equal to 0.1 mg, greater than 0.1 mg and less than 5 mg, greater than or equal to 5 mg and less than 10 mg, and greater than or equal to 10 mg. First, a one-way analysis of variance was conducted using the category of tap weight (four ranges, as described above) as the explanatory factor. Second, externally deleted studentized residuals were computed for each sample. Third, each externally deleted residual was compared to the extreme value likely to occur if the data were sampled from a normal distribution. The extreme value was defined to be the 0.025/(number of floor dust samples) lower or upper percentile of the normal distribution. This definition utilizes a Bonferoni adjustment to account for the simultaneous comparisons. Based on this analysis, three floor dust-lead concentrations were determined to be unusually large and six were determined to be unusually small. The sampling location, dwelling identification number, dust tap weight, dust-lead concentration, and externally deleted studentized residual for these nine samples are shown in Table 5. The window sill and trough dust data and paint data were examined for the two homes (2751402 and 0131102) with the large floor dust-lead concentrations. Dust-lead concentrations for window sill and trough samples were not unusual and neither home contained any damaged lead-based paint. Table 5. Results of Outlier Analysis Sampling Location Dry-room floor Wet-room floor Wet-room floor Dry-room floor Dry-room floor Wet-room floor Wet-room floor Entryway floor Entryway floor Dwelling ID 2751402 2751402 0131102 0310201 0430306 2622603 1041607 1731603 0340505 Dust Tap Weight (mg) 8.2 3.5 1.2 3.6 3580.1 681.1 4999.8 11 2041.7 Dust-Lead Concentration (Mg/g) 132,900 114,300 354,900 3.45 0.58 0.84 0.05 1.13 1.01 Externally Deleted Studentized Residual 4.62 3.97 4.83 -3.81 -4.34 -4.06 -6.21 -3.83 -3.92 12 ------- 2.3 LABORATORY ASSESSMENT OF LOW TAP WEIGHT SAMPLES As discussed in Section 2.1, dust-lead concentrations reported in the HUD National Survey may be biased due to use of tap weight in calculations of dust-lead concentrations. The potential bias in the dust-lead concentration is a function of the ratio of the total dust weight to the tap weight. Laboratory experiments were conducted using the Blue Nozzle vacuum to measure weight of residual dust in filter cassettes, tap weight, total dust weight, and ratio of total dust weight to tap weight. This section summarizes the results of those experiments and how the results may be used to estimate the bias in the HUD National Survey dust-lead concentrations. A more detailed discussion of the laboratory experiments, including tables of the collected data, is provided in Appendix A. Different weights of dust, of various particle sizes, were placed on a 12-inch tile substrate, and the Blue Nozzle sampler was used to vacuum the dust off the substrate. Vacuum sampling was done in accordance with the protocol specified in Appendix H of the EPA report "Laboratory Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners" [4]. After each experiment, tiles were cleaned with Kimwipes using distilled water and allowed to dry overnight. The tiles were judged to be clean (i.e., dust free) based on visual inspection. Each filter cassette was preweighed so that the weight of dust remaining in the filter cassette, after dust was tapped out of the cassette, could be determined. In this way, both the weight of the dust tapped out of the cassette, as well as the weight of dust remaining in the filter cassette, were determined. As shown in Table 6, experiments were conducted for a total of nine combinations of dust particle sizes and amount of dust tapped out of the cassette. Each combination of particle size and amount of dust was repeated at least five times. Although the dust test matrix states that the lowest range of dust to be tapped out was 0.2 - 5.0 mg, the minimum dust tapped out in any of the repetitions was 0.7 mg. House dust from a previously conducted EPA study [3,4] was used in these experiments. 13 ------- Table 6. Test Matrix for Laboratory Experiments Target Amount of Dust Tapped Out 0.2-5.0 mg 5.0-10.0 mg 10.0-20.0 mg Particle Sizes of Dust < 53 urn 8 6 8 150-212 urn 5 6 7 250-2000 urn 5 5 9 The ratio of the total dust weight to the tap weight was computed for each experiment. Ratio data are plotted against tap weight in Figure 5. The trend noted in Section 2.2 between dust-lead concentration and tap weight is also apparent in Figure 5; the observed ratios decrease with increasing tap weight. A regression model was fitted to the data to estimate the relationship between the observed ratios and tap weights. Details of the regression model are provided in Appendix A. The equation of the fitted model, shown as the solid line in Figure 5, is Ratio = 31 - 20*Tap Weight + 3.4*(Tap Weight)2 2.4 - 0.061*Tap Weight 1 Tap Weight < 2.9 mg 2.9 mg Tap Weight < 23.4 mg 23.4 mg Tap Weight The last segment (tap weight > 23.4 mg) was added so that the estimated ratio will always be greater than or equal to one. 2.4 CORRECTING THE BIAS IN DUST-LEAD CONCENTRATION The regression model presented in Section 2.3 was used to estimate the ratio of the total dust weight to tap weight for dust samples collected in the HUD National Survey. The ratios were predicted only for the floor and window samples collected from dry-rooms, wet-rooms and entranceways in the 284 privately-owned houses in the HUD National Survey. Dust-lead concentrations reported in the HUD National Survey were then corrected by dividing the reported dust-lead concentration by the predicted ratio of the total dust weight to tap weight. It should be noted that the regression model used to adjust the HUD National Survey data was based on a 14 ------- _ 20 o> o) 10 + a> "re +j o "o o "re 5 -- 0 0 + + + 10 15 20 Tap Weight (mg) 25 30 Figure 5. Ratio of Total Weight of Dust Divided by Tap Weight Plotted Against Tap Weight and Overlaid with Fitted Regression Model. laboratory experiment using only dry dust. Potential differences in the adhesive properties of dust with a higher moisture content may exist. The predicted ratios of total dust weight to tap weight based on a laboratory experiment that considered only dry dust samples may not be as accurate for dust samples in wet rooms. Nevertheless, the adjusted dust-lead concentrations for dust samples in wet rooms are expected to be more representative than those originally reported. Descriptive statistics for the corrected floor, window sill, window trough, and combined dust-lead concentrations are presented in Tables 7 to 10, respectively. Tables 1 to 4 provided analogous information for the uncorrected dust-lead concentrations. The inverse relationship between dust-lead concentration and tap weight noted in Tables 1 and 2 are no longer present in Tables 7 and 8, thereby providing evidence that the correction factor may have removed the bias. The corrected floor dust-lead concentrations are plotted against tap weights in Figures 6 to 9, with each of the plots corresponding to one of four tap weight classifications. To 15 ------- better show the data, the y-axis was truncated at 3,000 jig/g and floor dust samples with dust-lead concentrations greater than 3,000 jig/g were omitted from each of the plots. A total of eleven samples were excluded, two in Figure 7, one in Figure 8, and eight in Figure 9. The three samples from Figures 7 and 8 had dust-lead concentrations greater than 29,000 |ig/g, and the eight samples from Figure 9 had dust-lead concentrations ranging between 3,900 jig/g abd 12,000 |ig/g. Analogous plots for the uncorrected data were given in Figures 1 to 4. Once again, the trend of increased dust-lead concentration with decreased tap weight seen in Figure 2 is no longer apparent in the analogous figure, Figure 7. Figure 10 is similar to Figures 6 to 9; however, it shows the corrected dust-lead concentrations plotted against tap weight for all of the samples except for the three samples with concentrations exceeding 29,000 jig/g. The other eight samples excluded from Figure 9 are included in Figure 10. 3.0 WIPE SAMPLES IN HUD NATIONAL SURVEY The EPA report on the HUD National Survey [1] stated that a few dust samples were collected with wet wipes in homes where vacuuming was impossible (page 3-39). However, there are no identifiers in the database that distinguish between the wipe and vacuum samples. The laboratory records from the HUD National Survey were reviewed to determine which dust samples were collected by wipe sampling. Table 11 presents the dwelling identification numbers and sampling locations of the wipe samples. Analyses conducted for Section 403 are utilizing the dust samples collected from floors, window sills and window troughs in either the entryway, wet room or dry room in the 284 privately-owned residences in the HUD National Survey. Dust samples collected from the common areas of privately-owned residences and samples collected from publicly-owned residences are not being utilized. Only two of the samples listed in Table 11 meet this criteria: a window trough sample from the dry room of housing unit 1820802 and a window sill sample from the dry room of housing unit 0440602. The impact of these two samples being wipe samples rather than vacuum dust samples is negligible on the Section 403 Risk Assessment. Of the two wipe samples, the lead concentration is missing for one sample and non- missing for the other sample. For the purposes of analyses conducted to support Section 403, the dust-lead concentration of the one non-missing sample will be excluded. 16 ------- Table 7. Floor Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to< 1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 1 0 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 5 37 30 35 35 15 118 137 402 814 Geometric Mean 227 61.6 81.2 132 140 152 141 151 190 156 Geometric Standard Deviation 1.5 3.5 4.7 3.1 5.4 3.2 3.1 3.3 4.2 3.9 Minimum 162 1.65 6.20 6.26 1.56 20.2 11.6 0.642 0.0500 0.0500 Maximum 452 1080 29300 1650 51600 1770 68900 2550 11300 68900 Number >1000 0 1 1 2 1 1 6 5 42 59 Dust-Lead Loading (ug/ft2) Number 26 35 30 35 35 15 117 137 402 832 Geometric Mean 0.115 0.139 0.270 0.256 0.272 0.377 0.500 0.850 4.36 1.30 Geometric Standard Deviation 3.6 4.1 4.6 2.9 5.4 3.2 3.2 3.3 4.7 6.6 ------- Table 8. Window Sill Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to< 1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 1 0 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 27 41 26 19 13 13 51 44 105 339 Geometric Mean 132 97.1 171 266 425 209 329 316 665 304 Geometric Standard Deviation 4.7 8.5 5.5 3.5 4.1 4.3 5.7 4.7 6.7 6.4 Minimum 4.31 0.901 4.21 19.5 70.5 20.1 1.61 1.45 0.785 0.785 Maximum 1940 217000 14500 1980 4310 2110 47300 5990 102000 217000 Number >1000 3 6 3 4 5 2 13 11 41 88 Dust-Lead Loading (ug/ft2) Number 79 41 26 19 13 13 51 44 106 392 Geometric Mean 0.317 1.03 2.15 1.97 3.93 1.87 3.92 4.99 44.8 3.70 Geometric Standard Deviation 5.3 7.7 6.1 4.5 5.1 4.6 6.0 6.2 5.5 12 ------- Table 9. Window Trough Dust-Lead Concentrations Corrected for Bias and Dust-Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to< 1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 1 0 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 5 3 0 1 4 3 9 18 106 149 Geometric Mean 371 91.6 24.1 1110 2210 2410 1200 1770 1480 Geometric Standard Deviation 8.5 4.0 3.4 2.4 3.4 9.3 6.4 6.8 Minimum 84.5 19.2 24.1 213 1300 507 33.7 5.17 5.17 Maximum 15900 267 24.1 3500 6190 30000 59500 109000 109000 Number >1000 1 0 0 2 3 8 9 69 92 Dust-Lead Loading (ug/ft2) Number 14 3 0 1 4 3 9 18 106 158 Geometric Mean 0.546 0.703 0.366 9.88 25.7 34.5 33.3 243 76.6 Geometric Standard Deviation 6.5 6.4 3.0 2.2 3.9 9.6 6.2 15 ------- Table 10. Floor, Window Sill, and Window Trough Dust-Lead Concentrations Corrected for Bias and Dust- Lead Loadings by Tap Weight for the 284 Privately-Owned Houses in the HUD National Survey Tap Weight Range (mg) 0.1 > 0.1 to< 1 > 1 to < 2 > 2 to < 3 > 3 to < 4 > 4 to < 5 > 5 to < 1 0 > 1 0 to < 25 > 25 All Samples Dust-Lead Concentration (ug/g) Number 37 81 56 55 52 31 178 199 613 1302 Geometric Mean 163 78.7 115 163 217 225 208 214 346 240 Geometric Standard Deviation 4.7 5.8 5.2 3.4 5.5 4.3 4.4 4.6 6.2 5.6 Minimum 4.31 0.901 4.21 6.26 1.56 20.1 1.61 0.642 0.0500 0.0500 Maximum 15900 217000 29300 1980 51600 6190 68900 59500 109000 217000 Number >1000 4 7 4 6 8 6 27 25 152 239 Dust-Lead Loading (ug/ft2) Number 119 79 56 55 52 31 177 199 614 1382 Geometric Mean 0.271 0.418 0.707 0.522 0.700 1.11 1.12 1.75 13.0 2.78 Geometric Standard Deviation 5.3 7.5 7.1 4.7 8.3 6.1 6.3 6.5 9.7 12 to o ------- Table 11. Distribution of Wipe Samples Taken in the HUD National Survey LBPJD 0720300 1931906 1820802 1952506 0440602 1830801 1932300 1860204 1861202 1861400 1860501 1860600 1861004 1861509 1860709 1160308 1160506 1160704 1161108 1161207 1660604 1760503 1660703 1760305 1660406 1760206 1660505 Location (Sample ID) EW (61) 1 1 1 1 DF (62) 1 1 1 1 1 WF (63) 1 1 1 1 WS (64) 1 1 1 1 1 ww (65) 1 1 1 DS (66) 1 1 1 1 1 1 DW (67) 1 1 1 1 CH (68) CE (69) 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 CF (70) 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 cs (71) 1 1 1 1 1 1 1 1 1 cw (72) 1 1 Number of Wipe Samples 2 1 3 2 1 4 1 3 3 3 1 2 2 1 3 6 10 1 8 8 1 2 2 3 5 1 2 Public vs Private Private Private Private Private Private Private Private Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Public Total Number of Wipe Samples = 81 EW = Entryway floor sample (there are no window samples from entryways) WF = Wet Room Floor, WS = Wet Room Window Sill, WW = Wet Room Window Well (Trough) DF = Dry Room Floor, DS = Dry Room Window Sill, DW = Dry Room Window Well (Trough) CH = Common Area Hall, CE= Common Area Entryway CF = Common Area Floor, CS = Common Room Window Sill, CF = Common Room Floor, CW = Common Room Window Well (Trough) ------- HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight O.1 Dust Tap Weight (mg) Figure 6. Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weight Equal to 0.1 mg. 3000 - HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 2000 - 1000 - o ^ A A i I Dust Tap Weight (mg) Figure 7. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than 0.1 mg and Less than 5 mg. Two Samples with Dust-Lead Concentrations Greater than 29,000 ug/g are not Shown in the Plot. 22 ------- HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 2000- 1000- 8 Dust Tap Weight (mg) Figure 8. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 5 mg and less than 10 mg. One Sample with a Dust-Lead Concentration Greater than 29,000 ug/g is not Shown in the Plot. HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 10OO 2000 Dust Tap Weight (mg) Figure 9. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for Samples with Tap Weights Greater than or Equal to 10 mg. Eight Samples with Dust-Lead Concentrations Between 3,900 ug/g and 12,000 ug/g are not Shown in the Plot. 23 ------- HUD National Survey Data Private Houses Plot of Floor Dust Concentration vs. Floor Dust Tap Weight 12OOO - 11OOO - 1OOOO -_ 9OOO - 8OOO -_ 7OOO - 6OOO -_ 5OOO - 4OOO -_ 3OOO - 2OOO -_ 1OOO - O - 1000 2OOO 3OOO Dust Tap Weight (mg) 4OOO 5OOO Figure 10. Floor Dust-Lead Concentration Corrected for Bias Plotted Against Tap Weight for All Samples. Three Samples with Dust-Lead Concentrations Greater than 29,000 ug/g are not Shown in Plot. There is no reason to suspect the quality of the dust-lead loadings of these two samples. Therefore, they will be utilized in the analyses conducted for Section 403. However, it may be necessary to handle the lead loadings of these two samples differently if a conversion factor is implemented in Section 403 analyses. If the observed lead loadings collected via a Blue Nozzle vacuum are converted to wipe equivalent lead loadings then the conversion will not be required for these two samples. Likewise, if the observed lead loadings are compared to a Blue Nozzle standard equivalent to a wipe standard, then the wipe dust-lead loadings of these two samples should be compared directly against the standard defined for a wipe sample. 4.0 DISCUSSION, SUMMARY, AND CONCLUSIONS Dust Samples with a Tap Weight of 0.1 mg. Dust samples with a tap weight of 0.1 mg are a concern. Only 5 of the 40 floor dust samples with a tap weight of 0.1 mg had a non- missing dust-lead concentration. Both Westat and MRI were contacted in an attempt to 24 ------- determine what was the basis of the 0.1 mg number and what is the impact of a tap weight of 0.1 mg on the precision and accuracy of the measured dust-lead concentration. While it is generally believed, both by Westat and MRI, that 0.1 mg represents the limit of detection for the gravimetric analysis, no one at either Westat or MRI was able to confirm this. MRI stated that the balances typically employed in their metals laboratory measure sample weights in gram units to four decimal places. That is, the smallest nonzero weight possible for the balance commonly used is 0.1 mg. MRI stated that detectable dust-lead amounts can be measured for dust samples this small. However, if the dust weight is suspect then the dust-lead concentration is suspect. Due to the large number of missing dust-lead concentrations for samples with a tap weight of 0.1 mg, and the lack of confidence in this tap weight, dust-lead concentrations of the 0.1 mg tap weight samples will be excluded analyses conducted for Section 403. This decision applies only to the dust-lead concentrations of the 0.1 mg tap weight samples and not to the dust-lead loadings of these samples. Adjustments to Dust-Lead Concentrations Dust-lead concentrations reported in the HUD National Survey may be biased. Because tap weights were not used to compute dust- lead loadings, there is no reason to suspect that the dust-lead loadings are biased. It was shown in Section 2.2 that the HUD National Survey dust-lead concentrations tended to increase with decreased tap weight. This trend may be due to a bias. Laboratory experiments were conducted to generate a database for understanding and addressing the bias in dust-lead concentration computed via tap weight in the HUD National Survey. A regression model, developed for correcting the bias, was fitted to the laboratory data. It was shown in Section 2.4 that dust-lead concentrations corrected for the bias via the regression model no longer exhibited the trend of increased dust-lead concentration with decreased tap weight. Tap weights generated in the laboratory experiments and used to develop the regression model ranged from 0.7 mg to 27 mg. Tap weights in the HUD National Survey ranged from 0.1 mg to over 5000 mg. The regression model applied to the HUD National Survey was modified to predict a ratio of one for tap weights greater than 23.4 mg. However, use of the model to correct dust-lead concentrations for tap weights less than 0.7 mg may still be of concern. ------- The correction factor for lower tap weight samples is severe. The dust-lead concentration of a sample with a tap weight of 0.7 mg is reduced by a factor of 18.7; the factor ranges from approximately 5 for samples with a tap weight of 2 mg to approximately 2 for samples with a tap weight of 3 mg. Because the regression model was developed from data with tap weights all > 0.7 mg, its application might best be limited to samples with tap weights > 0.7 mg. The correction factor predicted by the regression equation may have over-corrected for lower tap weight samples. As shown in Table 7, the geometric mean of the corrected dust-lead concentrations of floor dust samples with a tap weight > 0.2 mg and < 1 mg was 62 |ig/g. The geometric means for groups with tap weights > 2 mg ranged from 132 to 190 |ig/g. There are 37 floor dust samples in the HUD National Survey with a tap weight > 0.2 mg and < 1 mg, of which 25 have tap weights < 0.7 mg and 12 have tap weights > 0.7 mg. The geometric means of the corrected dust-lead concentrations are 48 and 102 jig/g for the 25 and 12 samples, respectively. Therefore, the tendency for over-correction by the regression model may be strongest for dust samples with a tap weight less than 0.7 mg. For the purposes of analyses conducted to support Section 403, dust samples with a tap weight less than 0.7 mg will be excluded from the analysis, and the analysis will be conducted on the corrected dust-lead concentrations for all samples with a tap weight > 0.7 mg. There is no reason to suspect the quality of the dust-lead loadings for the 25 samples with a tap weight > 0.2 mg and < 0.7 mg, and therefore they will be included in Section 403 analyses. Table B-l in Appendix B lists the corrected dust-lead concentrations alongside those originally reported in the HUD National Survey. Outliers. A statistical analysis was performed to determine if any of the floor dust-lead concentrations for the 284 privately-owned residences in the HUD National Survey were statistical outliers. Three of the 814 floor dust-lead concentrations were determined to be unusually large. All three samples possessed dust-lead concentrations greater than 100,000 |ig/g. The corrected dust-lead concentrations of the three samples were all greater than 29,000 |ig/g. No basis was uncovered for suspecting the quality of these three samples. Therefore, these samples will be included in the analyses conducted for Section 403. 26 ------- Wipe Samples. Westat provided a table identifying the dwellings and locations of wipe samples. Only two of these samples are being used in analyses conducted for Section 403, because the remaining wipe samples were taken from common areas or publicly-owned houses. The dust-lead concentration is missing for one sample and will be excluded from Section 403 analyses for the other sample. There is no reason to suspect the quality of the lead loadings of the two samples. It will not be necessary to convert the lead loadings of these two samples to wipe equivalent loadings in the analyses conducted for Section 403. Summary. The following decisions were made regarding the quality of dust samples collected in the HUD National Survey for the purposes of the Section 403 Risk Assessment: 1. Dust-lead concentrations of dust samples with a tap weight of 0.1 mg will be excluded from the analysis of dust-lead concentrations. (Five out of 814 floor dust samples, 27 out of 340 window sill samples, and 5 out of 149 window trough samples.) 2. Dust-lead concentrations of dust samples with a tap weight greater than or equal to 0.2 mg and less than 0.7 mg will be excluded from the analysis of dust-lead concentrations. (25 out of 814 floor dust samples, 27 out of 340 window sill samples, and 1 out of 149 window trough samples.) 3. Dust-lead concentrations of dust samples with a tap weight greater than or equal to 0.7 mg will be corrected using the regression model presented in Section 2.3. The corrected dust-lead concentrations are presented in Appendix B. 4. The outliers identified in Section 2.2 (three samples were determined to be unusually large) will be included in the analyses. 5. The dust-lead concentrations of wipe samples collected from the privately-owned residences in the HUD National Survey from floors, window sills, and window troughs will be excluded from Section 403 analyses (1 window trough sample and 1 window sill sample). There is no reason to suspect the quality of the dust-lead loadings of the two samples. Therefore, they will be utilized in analyses conducted for Section 403. 5.0 REFERENCES 1. EPA, Report on the National Survey of Lead-Based Paint in Housing. Appendix I: Design and Methodology, 1995, U.S. Environmental Protection Agency. 27 ------- 2. EPA, Report on the National Survey of Lead-Based Paint in Housing. Appendix II: Analysis., 1995, U.S. Environmental Protection Agency. 3. EPA, Laboratory Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners. Volume I: Objectives, Methods, and Results, 1995, U.S. Environmental Protection Agency: Washington, D.C. 4. EPA, Laboratory Evaluation of Dust and Dust Lead Recoveries for Samples and Vacuum Cleaners. Volume II: Appendices from the Quality Assurance Project Plan, 1995, U.S. Environmental Protection Agency: Washington, D.C. 28 ------- APPENDIX A LABORATORY ASSESSMENT OF THE AMOUNT OF RESIDUAL DUST REMAINING IN BLUE NOZZLE FILTER CASSETTES A-l ------- Contents 1 Introduction A-3 2 Test Procedures A-4 3 Test Results A- 4 Conclusions A-19 A-2 ------- Section 1 Introduction The Department of Housing and Urban Development (HUD) National Survey collected dust samples for Pb analysis using the Blue Nozzle sampler device. This device collects dust in a plastic cassette containing a piece of filter paper to capture the dust. However, in the HUD National Survey, the filter cassette was not pre-weighed before sampling, and only the weight of dust that could be tapped out of the cassette was determined. The weight of dust remaining on the filter was not determined. Nevertheless, the total amount of Pb was determined by analysis of both the "tap" dust and filter cassette, combined. Subsequently, the concentration of Pb in the dust was calculated from the total amount of Pb found, divided by the weight of tap dust. Since that calculation necessarily neglected the weight of any dust retained in the filter cassette, the concentration results were probably biased high, but the extent of the bias is unknown. However, the bias in the Pb concentration measured by the weight of tap dust does not affect the measured dust-lead loadings in the HUD National Survey (i.e., |ig/ft2). The purpose of this project was to carry out laboratory experiments using the Blue Nozzle to determine the weight of dust "tapped out" and the weight of dust remaining in the filter cassette, and then to use those data to estimate the bias in the Pb concentrations that may have been present in the HUD National Survey. Subsequent sections of this report describe the procedures used in the experiments and the results of these experiments, along with the conclusions from the project. A-3 ------- Section 2 Test Procedures Different weights of dust, of various particle sizes, were placed on a 12-inch x 12-inch tile substrate, and the Blue Nozzle sampler was used to vacuum the dust off the substrate. The filter cassette was pre-weighed so that the weight of dust remaining in the filter cassette could be determined, after dust had been tapped out of the cassette. In this way, the weight of dust tapped out of the cassette was determined, as well as the weight of dust remaining in the filter cassette. These data were used to calculate the percentage of dust remaining in the filter cassette, as shown by the equation below. n/ „ • • • jrii ^ Wt of dust in filter cassette % Remaining in filter cassette = (Wt of dust in filter cassette) + (Wt of dust tapped out) The matrix of experiments covered three different particle sizes, and the amounts of dust tapped out covered three weight ranges. Each combination of particle size/amount was repeated at least five times (i.e., replicates) because of variability in the results for each combination, due to the low weight of dust tapped out, as discussed below. Also, the weight of dust tapped out varied because both the weight of dust applied to the tile substrate and the amount vacuumed off the substrate varied. The specific particle sizes and the target amounts of dust tapped out were as follows: Particle sizes of dust < 53 urn 150-212 |jm 250-2000 |jm Target amount of dust tapped out 0.2-5.0 mg 5.0-10.0 mg 10.0-20.0 mg A-4 ------- The three particle sizes shown above represent the range of sizes used by MRI in a previous study of house dust, where dust in vacuum cleaner bags was sieved to obtain different size ranges.1 These sieved dust samples were still available and were used in this study. Some preliminary experiments were carried out to determine how much dust must be applied in order to obtain the target "tapped" amounts shown. The substrate to which the dust was applied, for vacuuming with the Blue Nozzle, was 12-inch x 12-inch smooth tile, like that used in the previous MRI study. After each use, these tiles were wiped off with Kimwipes using distilled water and allowed to dry overnight. In the initial experiments, it was found that the weight of the filter cassette decreased by about 10 mg after vacuuming a clean tile (no dust),2 but after a second vacuuming of the clean tile, the weight decreased by less than 0.2 mg. Thus the procedure was to first use each cassette to vacuum a clean tile and then weigh the cassette to determine the tare weight. It should also be noted that after any vacuuming, the weight of the cassette decreases as it sits on the balance, but the rate of decrease slows over time. The weight recorded on the data sheets (i.e., final weight) was taken when the weight did not change more than 0.1 mg over 1 min. After the initial experiments, the procedure used in all tests was as given below, using the data entry form shown in Table A2-1. 1. Tare weigh an appropriate piece of weighing paper. 2. Add desired weight of dust onto weighing paper. 3. Transfer dust from weighing paper onto tile substrate. 4. Reweigh the paper to determine weight of dust actually transferred to tile. 5. Obtain cassette and use it to vacuum a clean tile. 6. Weigh the cassette (not including the top plastic part of the cassette), using this weight as the tare weight of the cassette. "Laboratory Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners," Volumes I and II. EPA 747-R-94-004A/B. U.S. Environmental Protection Agency: Washington, DC. March 1995. Possibly the result of partial dehydration of the filter on vacuuming, although this was not confirmed. A-5 ------- 7. Place the cassette back in the Blue Nozzle sampler and vacuum dust off the tile that was prepared in Step 3. 8. Tare weigh an appropriate size piece of weighing paper. 9. Tap dust out of the cassette onto tared weighing paper and determine weight of dust "tapped out." 10. Reweigh the cassette after tapping out dust. Vacuuming with the Blue Nozzle in each experiment was done in accordance with the protocol specified in Appendix H of the previous report titled "Laboratory Evaluation of Dust and Dust Lead Recoveries for Samplers and Vacuum Cleaners," except as given above. A-6 ------- Table A2-1. Data Entry Sheet Test No.. Date Time Operator. Particle Sizes: < 53|jm, 150-212|jm, 250-2000|jm Target Weight Tapped Out: 0.2-5 mg, 5-10 mg, 10-20 mg Replicate No.: 1, 2, 3, 4, or 5 A. Dust Applied Wt of paper plus dust Wt of paper after apply dust B. Dust Tapped Out (WT) Wt of paper plus dust Tare wt of paper C. Dust Remaining in Filter Cassette (WF) Wt of cassette Ta re wt of fi Ite r with dust (after cassette tapping dust out of cassette) Wt of dust applied Wt of dust tapped out (WT) Wt of dust remaining in filter cassette (WF) D. Calculation of Percent Remaining in Filter Cassette A-7 ------- W F t _ % Remaining = - - - x 100 = - i - si - x 100 = _ % WF + WT ( - g) + ( - g) A-8 Reviewed by. Date ------- Section 3 Test Results All of the test results are tabulated in Tables A3-1, A3-2, and A3-3. Each table contains the results for one of the three target amounts for the weight of dust tapped out. Each of the tables shows the results for the three particle sizes of dust used in the tests. These tables express the results in terms of the percent of dust remaining on the filter, and the ratio of the total weight (weight of dust tapped out plus weight of dust remaining in the cassette) to the weight of dust tapped out. This ratio is, in effect, a correction factor that might be applied to a lead concentration that had been calculated using only the weight of Pb tapped out. That is, the lead concentration should be divided by the ratio value to obtain a corrected Pb concentration. It had been anticipated that this ratio might be relatively large when the weight of dust tapped out was small (i.e., 0.2 to 5.0 mg), but that the ratio would decrease toward a ratio of 1.0 as the weight of dust tapped out increased. That is, for larger amounts of dust tapped out, the percent remaining in the filter cassette would be small. To investigate this expectation, the data in Tables A3-1, A3-2, and A3-3 were plotted as shown in Figures A3-1, A3-2, and A3-3 and were combined in Figure A3-4. A dashed reference line, at a ratio of 1.0, has been included in Figure A3-4. Examination of the results given in the figures shows ratios in the range of 1.1 to 2.7 for the two larger amounts of dust tapped out (i.e., 5 to 10 mg and 10 to 27 mg). On the average, the ratio appears to increase slightly as the amount tapped out decreases toward a value of about 3 mg. In addition, over this range the ratio does not appear to be significantly different for the three different particle size ranges. For an amount tapped out below about 3 mg, the ratio dramatically increases as the amount tapped out decreases. This certainly provides evidence of a bias in the Pb concentrations used in the HUD National Survey, where the Pb concentration was calculated using only the weight of dust tapped out, especially for those instances where the weight of dust tapped out was low (e.g., 0.2 mg). A-9 ------- Table A3-1. Summary of Test Results for Weight of Dust Tapped Out (in the range of 0.2 to 5.0 mg) Test No. Particle Size < 8 10 11 12 13 16 20 24 Wt of dust tapped out (mg) 53 |jm 1.4 0.7 2.4 1.4 3.5 1.3 1.3 3.9 Wt of dust remaining in filter cassette (mg) 10.8 11.6 2.7 10.0 5.9 15.8 19.4 19.7 Total wt (mg) 12.2 12.3 5.1 11.4 9.4 17.1 20.7 23.6 Percent of dust in filter cassette (%) 88.5 94.3 52.9 87.7 63 92.4 93.7 83.5 Ratio of total wtto wt tapped out 8.7 17.6 2.1 8.1 2.7 13 16 6.1 Particle Size 150 to 212 |jm 29 30 31 38 46 4.5 3.2 1.9 0.8 3.2 2.5 4.9 11.4 12.2 2.0 7.0 8.1 13.3 13.0 5.2 36 61 85.7 93.8 39 1.6 2.5 7.0 16 1.6 Particle Size 250 to 2000 |jm 47 51 59 60 R3 3.6 3.3 4.2 3.4 ? n 2.0 8.0 2.4 4.9 n Q 5.6 11.3 6.6 8.3 ? Q 36 71 36 59 31 1.6 3.4 1.6 2.4 1 5 A-10 ------- Table A3-2. Summary of Test Results for Weight of Dust Tapped Out (in the range of 5.0 to 10.0 mg) Test No. Particle Size < 7 9 15 19 22 27 Wt of dust tapped out (mg) 53 |jm 7.8 5.2 5.7 8.9 7.4 9.9 Wt of dust remaining in filter cassette (mg) 5.4 3.4 9.9 13.1 7.3 3.6 Total wt (mg) 13.2 8.6 15.6 22.0 14.7 13.5 Percent of dust in filter cassette (%) 41 40 64 59.5 50 27 Ratio of total wtto wt tapped out 1.7 1.7 2.7 2.5 2.0 1.4 Particle Size 150 to 212 |jm 34 35 36 39 42 43 6.5 8.8 9.5 6.1 8.7 8.8 2.1 2.7 4.0 6.8 2.3 9.7 8.6 11.5 13.5 12.9 11.0 18.5 24 24 30 53 21 52 1.3 1.3 1.4 2.1 1.3 2.1 Particle Size 250 to 2000 |jm 48 49 62 64 fiS 8.0 7.8 6.6 6.3 5 1 4.2 2.5 1.6 8.6 in 12.2 10.3 8.2 14.9 8 1 34 24 20 58 17 1.5 1.3 1.2 2.4 1 R A-ll ------- Table A3-3. Summary of Test Results for Weight of Dust Tapped Out (in the range of 10.0 to 30.0 mg) Test No. Particle Size < 14 17 18 21 23 25 26 28 Wt of dust tapped out (mg) 53 |jm 13.3 11.5 24.2 12.0 24.3 10.1 24.7 14.1 Wt of dust remaining in filter cassette (mg) 2.7 2.8 8.1 6.6 8.7 14.0 8.6 6.8 Total wt (mg) 16.0 14.3 32.3 18.6 33.0 24.1 33.3 20.9 Percent of dust in filter cassette (%) 17 20 25 36 26 58.1 26 33 Ratio of total wtto wt tapped out 1.2 1.2 1.3 1.6 1.4 2.4 1.3 1.5 Particle Size 150 to 212 |jm 32 33 37 40 41 44 45 13.3 13.1 22.2 13.9 21.8 17.2 16.2 3.1 4.8 3.8 2.8 3.9 4.8 8.7 16.4 17.9 26.0 16.7 25.7 22.0 24.9 19 27 15 17 15 22 35 1.2 1.4 1.2 1.2 1.2 1.3 1.5 Particle Size 250 to 2000 |jm 50 52 53 54 55 56 57 58 R1 16.7 24.3 13.1 27.2 27.2 15.4 18.9 16.4 11 5 15.2 9.5 11.1 9.5 11.8 3.2 8.5 10.2 n 7 31.9 33.8 24.2 36.7 39.0 18.6 27.4 26.6 19 9 47.6 28 45.9 26 30.3 17 31 38.3 5 7 1.9 1.4 1.8 1.3 1.4 1.2 1.4 1.6 1 1 A-12 ------- 18.0 16.0 14.0 .0) 12.0 Q. 3 O — O O • ro CC 10.0 8.0 6.0 4.0 2.0 0.0 0.0 1 .0 2.0 3.0 Weight of dust tapped out (mg) 4.0 i Particle size < 53 |jm » Particle size 150 |jm to 212 |jm ^ Particle size 250 |jm to 2,000 |jm 5.0 Figure A3-1. Ratio of Total Wt of Dust to Wt of Dust Tapped Out as a Function of the Wt of Dust Tapped Out over the Range of 0.2 to 5.0 mg. ------- 5.0 4.5 4.0 ^ 3.5 D) 1 I 3.0 T3 Q. •? 2.5 D) 0 2.0 o o 1.5 ro ce 1 .0 0.5 0.0 5.0 6.0 7.0 8.0 Weight of dust tapped out (mg) 9.0 10.0 I Particle size < 53 |jm 0 Particle size 150 |jm to 212 |jm ^Particle size 250 |jm to 2,000 |jm Figure A3-2. Ratio of Total Wt of Dust to Wt of Dust Tapped Out as a Function of the Wt of Dust Tapped Out over the Range of 5.0 to 10.0 mg. ------- D) 1 O T3 0 CL CL O -t-« .C D) ro ce 5.0 4.5 4.0 3.5 3.0 2.5 2.0 1 .5 1 .0 0.5 0.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 Weight of dust tapped out (mg) 24.0 26.0 28.0 jParticle size < 53 |jm ^Particle size 150 |jm to 212 |jm ^Particle size 250 |jm to 2,000 |jm 30.0 Figure A3-3. Ratio of Total Wt of Dust to Wt of Dust Tapped Out as a Function of the Wt of Dust Tapped Out over the Range of 10.0to 30.0 mg. ------- D) i 20.0 18.0 16.0 14.0 o 12.0 Q. Q. (0 D) 10.0 8.0 "B 6.0 g 15 or 4.0 2.0 0.0 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 22.0 24.0 26.0 28.0 Weight of dust tapped out (mg) Particle size < 53 urn « Particle size 150 um to 212 um ± Particle size 250 um to 2,000 um Fitted regression Figure A3-4. Ratio of Total Wt of Dust Tapped Out as a Function of the Wt of Dust Tapped Out over the Entire Range of 0.2 to 30.0 mg. ------- If an attempt were to be made to correct the Pb concentrations from the HUD National Survey, the results shown in the figures could be used for that purpose. That is, the reported Pb concentration could be divided by the value of the ratio that corresponds to the specific weight of dust tapped out. This calculation is illustrated by the equation below: r^ >. j nu r^ Original Pb Concentration Corrected Pb Cone = —2 Value of Ratio where: Value of Ratio is determined based on the weight of dust tapped out, which was used in the original calculation of the Pb concentration, as discussed below. To provide a method for determination of the ratio value that could be used to correct Pb concentrations calculated in the HUD National Survey, a regression analysis was performed on the data from these experiments (i.e., Tables A3-1, A3-2, and A3-3). A segmented linear model was fit to all 59 data points using PROC NLIN of SAS, a statistical software package. The parameters of a second-order model followed by a first-order model were estimated as well as the value of weight of dust tapped out at which the regression line changes shape. Table A3-4 summarizes the regression results. The following two equations provide the best fit to the data: For Weight of Dust Tapped Out (Wt in mg)) below 2.90 mg: Ratio = 30.71-19.54 (Wt) + 3.36 (Wt)2 \i For Weight of Dust Tapped Out (Wt in mg) above 2.90 mg: Ratio = 2.43-0.061 (Wt) A-17 ------- Table A3-4. Regression Model Results Tap dust range 0 to 2.90 mg 2.90 to 24.5 mg Model parameters3 Intercept (se) 95% Cl 30.71 (2.27) [26.16,35.26] 2.43 (NC)C n 93 ? RRld Linear term (se) 95% Cl 19.54(2.62) [ 24.79, 14.30] 0.061 (0.023) r n ma nni4i Quadratic term (se) 95% Cl 3.36 (0.65) [2.06, 4.65] NA Model summary" R2 = 86% MSE = 1.4 se = standard error of parameter estimate 95% Cl = 95% confidence interval of parameter estimate R2-value = percent variance in data explained by model (adjusted for number of parameters) MSE = Mean Square Error of estimated ratio NC: not calculated 95% Cl for ratio of 2.25 calculated at Weighttapped of 2.90 For any given weight of dust tapped out in the HUD National Survey data, the appropriate equation above could be used to calculate the ratio value that should be used to correct the Pb concentration that was calculated in the HUD National Survey using that weight of dust tapped out. Use of the equations for that purpose does, of course, involve some uncertainty. This is because the equations are based on the data from these laboratory experiments, which utilized sieved dust that may not duplicate the characteristics of the actual dust sampled in the HUD National Survey. Although differences in dust characteristics could affect the ratio values, given the limited sample set it is not possible to predict the nature and magnitude of the effect of such differences on the equations developed from the laboratory experiments. Based on the above equations, the corrected Pb concentrations may decrease by a factor ranging from 2.3 to 1.0 for the larger weights of dust tapped out (above 2.90 mg). But for weights of dust tapped out below 2.90 mg, the corrected Pb concentrations would decrease by a factor that might range from 2.3 (for 2.90 mg tapped out) up to 21.8 (for 0.5 mg tapped out). It should be noted that in these experiments, the lowest amount of dust tapped out was 0.7 mg, and it is very difficult to obtain such low amounts of dust tapped out. In this report, the above equation yielded a ratio of 18.7 for 0.7 mg tapped out and a maximum ratio of 30.7 for 0.0 mg tapped out. Obviously, it would be possible theoretically for no A-18 ------- dust to be tapped out (0.0 mg) when there was some weight of dust in the cassettes, so the ratio could be infinitely high. Thus, the use of the second equation above is only a best fit of the data down to a weight tapped out of 0.7 mg. Use of the equation for lesser amounts (e.g., < 0.7 mg tapped out) is uncertain, but it should provide conservatively low ratios for the lesser amounts. A-19 ------- A-20 ------- Section 4 Conclusions From the results discussed in the previous section, it can be concluded that the total weight of dust collected in Blue Nozzle cassettes is higher than the weight of dust that can be tapped out the cassette, especially for smaller weights of dust tapped out. It can, therefore, also be concluded that Pb concentrations in dust, determined using only the weight of dust tapped out, are biased high and that the extent of the bias is likely quite high for very small weights of dust tapped out. A-21 ------- APPENDIX B DATA TABLES FOR DUST-LEAD CONCENTRATIONS FOR FLOOR, WINDOW SILL, AND WINDOW TROUGH SAMPLES IN THE 284 PRIVATELY-OWNED HOUSES IN THE HUD NATIONAL SURVEY B-l ------- Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0130708 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0130906 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0131003 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0131102 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0131201 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Dust Tap Weight (mg) Uncarpeted Carpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Original Dust-Lead Concentration (pg/g) Revised Dust-Lead Concentration (pg/g) 95. 40 B-2 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted B-3 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0311100 Entryway Dry Floor Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted B-4 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted 0321307 Entryway Dry Floor Wet Floor j.l B-5 ------- Dry Sill Wet Sill Dry Trough Wet Trough 0330308 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0331009 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0340406 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Carpeted Carpeted Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0340802 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Dust Tap Weight (mg) Uncarpeted Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted Original Dust-Lead Concentration (pg/g) Revised Dust-Lead Concentration (pg/g) B-6 ------- Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted 0351205 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Uncarpeted Uncarpeted Uncarpeted Uncarpeted B-7 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 0430108 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough B-8 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration B-9 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 716.14 1152.84 256.50 5845835.49 12674.60 33237.82 26355.81 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Table B-l. Original and Revised Dust-Lead Concentrations for All B-10 ------- Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 0530105 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0530600 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0531301 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted 0531400 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0540203 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0541201 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0541300 Entryway Dry Floor B-ll ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor B-12 ------- Dry Sill Wet Sill Dry Trough Wet Trough 0720300 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey 0720706 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0730606 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0820506 Entryway Dry Floor Wet Floor Dry Sill Dust Tap Weight (mg) Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Carpeted Carpeted Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Original Dust-Lead Concentration (pg/g) Revised Dust-Lead Concentration (pg/g) B-13 ------- Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1.2 Uncarpeted 0.1 Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill B-14 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Uncarpeted Carpeted Uncarpeted B-15 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough B-16 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location 1020502 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Uncarpeted B-17 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 0 . 5 4.1 B-18 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey B-19 ------- House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill B-20 ------- 34.6 Uncarpeted 18.1 Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1322601 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted B-21 ------- 1323609 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough B-22 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location 1411909 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted 1450907 Entryway B-23 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 1520204 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1521400 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted 1521509 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted 1919.75 1919.75 1530104 Entryway Dry Floor B-24 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location 1531201 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor B-25 ------- Dry Wet Dry Wet 1531706 Ent Dry Wet Dry Wet Dry Wet 1540202 Ent Dry Wet Dry Wet Dry Wet 1540400 Ent Dry Wet Dry Wet Dry Wet 1540806 Ent Dry Wet Dry Wet Dry Wet Sill Sill Trough Trough ryway Floor Floor Sill Sill Trough Trough ryway Floor Floor Sill Sill Trough Trough ryway Floor Floor Sill Sill Trough Trough ryway Floor Floor Sill Sill Trough Trough 6. 0 . 65. 0 . 108. 23. 14 . 445. 0 . 825. 269. 9 . 10. 3. 0. 0 . 244 . 650. 165. 121. 7 . 49. 0 . 0. 1011. 324 . 5 . 74 . 0. 0 . 152. 0 . . 4 .1 . 3 .1 .3 . 5 . 6 .8 . 4 9 .1 .1 . 3 . 0 .1 .1 . 8 .2 . 0 . 6 .3 . 5 .1 .1 .2 , 7 ^ . 9 .1 .1 . 2 .1 Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Uncarpeted Carpeted Carpeted Carpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Dust Tap Weight (mg) Original Dust-Lead Revised Dust-Lead Concentration Concentration 1541200 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted 1550102 Entryway Dry Floor Wet Floor Dry Sill 58.5 Carpeted 0.1 17.7 Uncarpeted 7.0 Uncarpeted B-26 ------- Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill B-27 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1730803 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted 1731603 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted 1740901 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1741800 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted 111.87 111.87 Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Dust Tap Weight Original Dust-Lead Revised Dust-Lead Concentration Concentration B-28 ------- ID Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough B-29 ------- Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 1931906 Entryway B-30 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted 1952506 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted B-31 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor B-32 ------- Dry Sill Wet Sill Dry Trough Wet Trough 2130706 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2131902 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Uncarpeted Carpeted Carpeted Uncarpeted Carpeted Uncarpeted Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Dust Tap Weight (mg) Uncarpeted Carpeted Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Original Dust-Lead Concentration (pg/g) Revised Dust-Lead Concentration (pg/g) 2151207 Entryway Dry Floor Wet Floor Dry Sill B-33 ------- Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill B-34 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 15538.53 15538.53 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 2343606 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough B-35 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2421109 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location '441509 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Uncarpeted Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted B-36 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location B-37 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2521201 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted 2521300 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the B-38 ------- House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2551000 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor B-39 ------- Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey Dust Tap Weight (mg) Original Dust-Lead Concentration (pg/g) Revised Dust-Lead Concentration (pg/g) Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2610103 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2611101 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2620508 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Carpeted Carpeted Carpeted Carpeted Uncarpeted Carpeted Carpeted Uncarpeted B-40 ------- Wet Sill Dry Trough Wet Trough Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted 303 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Carpeted Carpeted Uncarpeted Uncarpeted B-41 ------- Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 2721009 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 2731503 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted 2731800 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough B-42 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough B-43 ------- Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough ?840403 Entryway B-44 ------- Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted Carpeted Carpeted Carpeted Uncarpeted Uncarpeted Carpeted Carpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Dust Tap Original Dust-Lead Revised Dust-Lead Weight Surface Concentration Concentration (mg) Sampled (ug/g) (ug/g) 2931202 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted B-45 ------- Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough 0.1 Uncarpeted 0.1 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Uncarpeted Uncarpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Table B-l. Original and Revised Dust-Lead Concentrations for All Floor, Window Sill, and Window Trough Samples in the 284 Privately-Owned Houses in the HUD National Survey House ID Sampling Location Original Dust-Lead Revised Dust-Lead Surface Concentration Concentration 3020401 Entryway Dry Floor Wet Floor B-46 ------- Dry Sill Wet Sill Dry Trough Wet Trough Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough j.l Uncarpeted Uncarpeted Uncarpeted Uncarpeted Uncarpeted Carpeted Carpeted 3050101 Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted Uncarpeted Entryway Dry Floor Wet Floor Dry Sill Wet Sill Dry Trough Wet Trough Carpeted Carpeted Uncarpeted B-47 ------- 50272-101 REPORT DOCUMENTATION PAGE 1. REPORT NO. EPA747-R-96-011 3. Recipient's Accession No. 4. Title and Subtitle Adjustments to the HUD National Survey Dust Data For Section 403 Analyses 5. Report Date December 1996 6. 7. Author(s) Ronald G. Menton, Alan D. Pate, Paul G. Gorman 8. Performing Organization Report No. 9. Performing Organization Name and Address Battelle Memorial Institute 505 King Avenue Columbus, Ohio 43201-2693 10. Project/Task/Work Unit No. G002889-10,0003134-08 Midwest Research Institute 425 Volker Road Kansas City, Missouri 64110 11. Contract(C) or Grant(G) No. (C) 68-D5-0008,68-D2-0139 (G) 12. Sponsoring Organization Name and Address U.S. Environmental Protection Agency Office of Pollution Prevention and Toxics 401 M. Street, S.W. Washington, D.C. 20460 13. Type of Report & Period Covered Final Report 14. 15. Supplementary Notes 16. Abstract (Limit 200 words) Analyses being conducted to support the rule-making for Section 403 of Title IV of the Toxic Substances and Control Act require information on environmental-lead levels in the national housing stock. The primary source of national environmental-lead levels is the HUD National Survey; however, an issue regarding the quality of dust-lead concentrations for dust samples collected in the HUD National Survey was raised. Only the weight of dust collected in the vacuum cassette was measured; rather than also measuring the amount of dust remaining on the vacuum filter. Dust-lead concentrations were calculated as the total lead found in the tapped-out dust and residual dust on the filter divided by the weight of the tapped-out dust. The dust-lead concentration will be biased if the tapped-out weight underestimates the total dust weight of the sample. The objective of this study was to assess the potential bias and define a way to adjust for it. Laboratory experiments were conducted to generate a database for understanding and addressing the bias, and a regression model developed for correcting the bias was fitted to the laboratory data. Dust-lead concentrations reported in the HUD National Survey were then adjusted using correction factors predicted by the regression model. 17. Document Analysis a. Descriptors Lead, Dust Sample, Dust-Lead Concentration, Bias, Statistical Analysis b. Identifiers/Open-Ended Terms Blue Nozzle Vacuum, Tap Weight, Wipe Sample c. COSATI Field/Group B-48 ------- 18. Availability Statement Release Unlimited 19. Security Class (This Report) Unclassified 20. Security Class (This Page) Unclassified 21. No. of Pages 100 22. Price (SeeANSI-Z39.18) OPTIONAL FORM 272 (4-77) (Formerly NTIS-35) Department of Commerce B-49 ------- |