nelie Technology To Work REPORT Draft Final Report COMPREHENSIVE ABATEMENT PERFORMANCE PILOT STUDY VOLUME II MULTI-ELEMENT DATA ANALYSES To Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency March 1, 1996 ------- Review Draft - Do Not Cite or Quote March 1, 1996 REVIEW DRAFT DRAFT FINAL REPORT COMPREHENSIVE ABATEMENT PERFORMANCE PILOT STUDY VOLUME II: MULTI-ELEMENT DATA ANALYSES Prepared by . BATTELLE 505 King Avenue Columbus, Ohio 43201-2693 and Midwest Research Institute 425 Volker Boulevard Kansas City, MO 64110 for Technical Programs Branch Chemical Management Division Office of Prevention, Pesticides, and Toxic Substances Office of Pollution Prevention and Toxics U.S. Environmental Protection Agency Washington, DC 20460 ------- Review Draft -- Do Not Cite or Quote U.S. EPA DISCLAI1 R This document is a preliminary draft. It has not been released formally by the Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency. It is being circulated for comments on its technical merit and policy implications. This report was prepared under contract to an agency of the United States Government. Neither the United States Government nor any of its employees, contractors, subcontractors, or their employees makes any warranty, expressed or implied, or assumes any legal liability or responsibility for any third party’s use of or the results of such use of any information, apparatus, product, or process disclosed in this report, or represents that its use by such third party would not infringe on privately owned rights. Publication of the data in this document does not signify that the contents necessarily reflect the joint or separate views and policies of each sponsoring agency. Mention of trade names or commercial products does not constitute endorsement or recommendation for use. BATTELLE DISCLAThThR This is a report of research performed for the United States Government by Battelle. Because of the uncertainties inherent in experimental or research work, Battelle assumes no responsibility or liability for any consequences of use, misuse, inability to use, or reliance upon the information contained herein, beyond any express obligations embodied in the governing written agreement between Battelle and the United States Government. ------- Review Draft -- Do Not Cite or Quote AUTHORS AND CONTRIBUTORS This study was funded and managed by the U.S. Environmental Protection Agency. The study was conducted collaboratively by two organizations under contract to the Environmental Protection Agency, Battelle Memorial Institute and Midwest Research Institute. Each organization’s responsibilities and key staff are listed below. Battelle Memorial Institute (Battelle) Battelle was responsible for the design of the study, for producing the design documentation and the Quality Assurance Project Plan, for developing training for the field teams, for recruiting cooperators for the study, for providing team leaders for the field teams, for auditing the field teams, for data management of combined study data, for auditing the study data, for conducting the statistical analysis of the data, and for writing the final report. Key staff included: Bruce Buxton, Steve Rust, Tamara Collins, Fred Todt, John Kinateder, Nancy McMillan, Matt Palmgren, Nick Sasso, Robin Hertz, and Casey Boudreau. Midwest Research Institute (MRI) Midwest Research Institute was responsible for participating in the planning for the study, for writing certain chapters and appendices in the Quality Assurance Project Plan, for designing and producing a vacuum device for collecting field samples, for developing training for the field teams, for providing the technicians who collected the field samples, for auditing the field teams, for conducting the laboratory analysis of the field samples, for managing the data associated with the field samples, for auditing the laboratory results, and for contributing sections of the final report. Key staff included: Gary Dewalt, Paul Constant, Jim McHugh, and Jack Balsinger. U.S. Environmental Protection Agency (EPA) The Environmental Protection Agency was responsible for managing the study, for reviewing the design and the Quality Assurance Project Plan, for assessing the performance of the recruiters and the field teams, for reviewing audit reports, for reviewing the final report, and for arranging the peer review of the design and the final report. The EPA Work Assignment Managers were Ben Lim and John Schwemberger. The EPA Project Officers were Gary Grindstaff and Joe Breen. ------- Review Draft -. Do Not Cite or Quote TABLE OF CONTENTS Page EXECUTIVE SUMMARY . . . v 1.0 INTRODUCTION . 1 1.1 Study Design 1 1.2 Data 2 2.0 ANALYSIS RESULTS 4 2.1 Characterization of Element Levels 5 2.2 Abatement and Renovation Effects 14 2.2.1 Abatement and Renovation Effects By Element 14 2.2.2 Abatement and Renovation Effects Across Elements 25 2.3 Relationships Among the Elements 29 2.3.1 Bivariate Relationships (Correlations) 29 2.3.2 Multivariate Relationships (Principal Components) 33 3.0 CONCLUSIONS . . . 36 4.0 RECOMMENDATIONS FOR FUTURE WORK . . . 38 5.0 REFERENCES . . . . 39 LIST OF TABLES Table 1 Abbreviations for Sample Types Used in Tables and Figures 4 Table 2 Abatement and Renovation History by House 5 Table 3 Results of Analysis of Variance to Test for Significant Differences Among Sample Types, by Element 13 Table 4 Geometric Mean Concentration and Log Standard Deviation Across Houses by Sample Type 15 1 ------- TABLE OF CONTENTS (continued) Page Table 5 Model Estimates and Log Standard Errors of Geometric Mean Concentrations in Unrenovated, Unabated Houses 17 Table 6 Estimates and Log Standard Errors of Multiplicative Renovation Effects . . . 18 Table 7 Estimates and Log Standard Errors of Multiplicative Abatement Effects . . . . . . . 19 Table 8 Principal Components for Unit Mean Log-Concentration by Sample Type 27 Table 9 Principal Components for Unrenovated, Unabated Home Averages, Abatement Effects, and Renovation Effects . . . 35 LIST OF FIGUPES Figure la Lead Concentration vs. Sample Type (Geometric House Mean) 6 Figure lb Aluminum Concentration vs. Sample Type (Geometric House Mean) 6 Figure ic Barium Concentration vs. Sample Type (Geometric House Mean) 7 Figure id Cadmium Concentration vs. Sample Type (Geometric House Mean) 7 Figure le Calcium Concentration vs. Sample Type (Geometric House Mean) 8 Figure if Chromium Concentration vs. Sample Type (Geometric House Mean) 8 Figure ig Magnesium Concentration vs. Sample Type (Geometric House Mean) 9 Figure lh Nickel Concentration vs. Sample Type (Geometric House Mean) 9 Figure 11 Potassium Concentration vs. Sample Type (Geometric House Mean) 10 ii ------- TABLE OF CONTENTS (continued) Page Figure lj Titanium Concentration vs. Sample Type (Geometric House Mean) 10 Figure 1k Zinc Concentration vs. Sample Type (Geometric House Mean) 11 Figure 2a Block Chart of Estimated Average Log- Concentration in Unrenovated, Unabated Units for Window and Air Duct Dust Samples . . . . 21 Figure 2b Block Chart of Estimated Average Log- Concentration in Unrenovated, Unabated Units for Floor and Textile Dust Samples 22 Figure 2c Block Chart of Estimated Average Log- Concentration in tinrenovated, Unabated Units for Soil Samples 23 Figure 3a Plot of First Two Principal Components of Mean Log-Concentrations for Dust Samples . . . . 28 Figure 3b Plot of First Two Principal Components of Mean Log—Concentrations for Soil Samples . . . . 28 Figure 4a Window Channel House Mean Correlation Scatterplot 30 Figure 4b Window Stool House Mean Correlation Scatterplot 30 Figure 4c Air Duct House Mean Correlation Scatterplot . . . . 30 Figure 4d Floor House Mean Correlation Scatterplot 30 Figure 4e Bedcover/Rug/tipholstery House Mean Correlation Scatterplot 31 Figure 4f Entryway Dust House Mean Correlation Scatterplot 31 Figure 4g Entryway Soil House Mean Correlation Scatterplot 31 Figure 4h Foundation Soil House Mean Correlation Scatterplot 31 iii ------- TABLE OF CONTENTS (continued) Page Figure 4± Boundary Soil House Mean Correlation Scatterplot 32 Figure 5 Key to Relation Between Shape of Ellipse and Observed Correlation in Figures 4a Through 4i 32 Figure 6 First Two Principal Components for Each Building Component, Plotted Versus Each Other for Unrenovated, Unabated Unit Mean Log-Concentrations, Renovation Effects, and Abatement Effects 38 LIST OF APPENDICES Appendix A Summary of Multi-Element Data A-i Appendix B Outlier Analysis for the CAPS Pilot Multi—Element Data B-i iv ------- E CUTXVE SU)* AR! This report presents the results of a statistical analysis of multi—element data collected during the pilot study that preceded the Comprehensive Abatement Performance (CAP) Study. The goal of the CAP Study was to assess the long-term impact of lead-based paint abatement. The pilot study was conducted to test the sampling and analysis protocols that were intended for the full study. These protocols called for determining the levels of lead in dust and soil samples collected at residential units. For the multi-element analysis, concentrations of lead as well as those of the following ten elements were measured in the study: aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc. The data used in this analysis consisted of these element concentrations in indoor dust and soil sample types (e.g., floor dust and entryway soil) collected from six houses. In addition to lead, the elements barium, cadmium, chromium, titanium, and zinc were selected for analysis in this study due to their common use in the composition of paint. The multi-element approach was undertaken with the perception that these elements might provide a “tracer” for dust samples which may have their origin in paint. Aluminum, calcium, magnesium, nickel, and potassium were selected as tracer elements for dust samples which may have their origin in soil. Soil has been suggested as a reservoir holding lead from gasoline emissions and lead—based paint. The multi—element statistical analysis presented in this report addresses the following three study objectives: (1) Characterize the concentration of lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, V ------- potassium, titanium, and zinc in household dust and soil, (2) Characterize the relationships between renovation and abatement history and the concentrations of these elements in household dust and soil, and (3) Investigate the relationship between concentrations of these elements in the different types of samples collected (i.e., samples of different media and taken from different locations), and compare these relationships across sample types. An examination of descriptive statistics including geometric mean measures provided insight into the first study objective. Analysis of variance was primarily used to address the second objective, regarding the impacts of abatement and renovation. Multivariate statistical techniques, including a correlation analysis and principal components analysis, were employed to address the third objective. The highest geometric mean concentrations were observed for calcium in the indoor dust samples. For the outdoor soil samples, the highest levels were observed for aluminum. Titanium and aluminum concentrations averaged higher in soil samples than in dust samples, and were also higher in entryway dust samples than in floor dust samples. Except for lead, there were no strong differences observed between levels of the different elements measured in abated and unabated houses. The strongest correlations in concentrations of different elements were observed in soil samples. Indoors, correlations were less clear. Of the elements measured besides lead, zinc was most frequently correlated with lead, both within sample types and across sample types. The concentrations of the elements in the following groups of sample types were found to be similar: (i) entryway, foundation, and boundary soil samples; vi ------- (ii) floor, entryway, bedcover/rug/upholstery, and window stools, and (iii) air ducts and window channels. In general, the sparse data available for use in this analysis prevented conclusive source assessment of lead in household dust. This being only a pilot study, strong relationships were not anticipated. The full CAP Study in which similar and additional data were collected from 52 houses would provide nine times as much information to address this issue. vii ------- COMPREHENSIVE ABATEMENT PERPORMP NCE PILOT STUD!: MULTI-ELEMENT DATA ANALYSES 1.0 INTRODUCTION This report presents the results of a multi—element analysis of data obtained during a pilot study that preceded the Comprehensive Abatement Performance (CAP) Study. This represents Volume II of the CAP Pilot report. Volume I dealt exclusively with the statistical analysis of observed levels of lead (US EPA, 1995) . The goal of the CAP Study was to assess the long-term impact of lead—based paint abatement. The pilot study was conducted to test the sampling and analysis protocols that were intended for the full study. These protocols called for determining the levels of lead in dust and soil samples collected at residential units. 1.1 STUDY DESIGN In the CAP Pilot study, six houses of differing abatement history were sampled. These houses were located in Denver, Colorado. Two houses were abated by enclosure or encapsulation methods, two were abated by removal methods, and two were control houses identified as being free from lead-based paint by previous XRF-testing. Along with the determinations of lead obtained in the study, levels of ten other metals were measured within dust and soil samples taken at these houses: aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium and zinc. Five of these metals (barium, cadmium, chromium, titanium and zinc) are known to be used in the composition of paint. The other five elements are known to be present primarily in other sources. For example, magnesium is found in clay which is often observed in soil samples. The purpose of measuring the levels of these other metals in the samples was to identify groups of sample types that appear to ------- have come from similar sources with the ultimate goal of identifying prominent sources of lead found in household dust. The major objectives addressed in the analysis of the multi-element data from the pilot were to: (1) Characterize the concentrations of lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc in household dust and soil, (2) Characterize the relationships between renovation and abatement history and the concentrations of these elements in household dust and soil, and (3) Investigate how the concentrations of these elements are related, specifically elements in household dust and exterior soil, air ducts, and bedcover/rugs /upholstery. The intention of this examination was to identify analysis methods for evaluating multi—element data, and to apply these methods to pilot study data to identify any strong relationships. With data available for only six housing units, most relationships were not strongly detectable. The following subsection describes the data and a summary of the outlier analysis performed. Section 2 describes the analyses performed and their results. Section 3 provides conclusions. As this analysis was performed on data from a pilot study, Section 4 describes potential future work which could be done to extend these results. 1.2 IA A total of 109 regular dust samples were collected in the CAP pilot study by vacuum methods. By design, 18 dust samples were to be collected from each house. For each of the six dust sample types (window channel, window stool, air duct, floor, bedcover/rug/upholstery, and entryway), two different 2 ------- rooms were targeted for sampling. Forty-eight (48) soil samples were collected. Soil samples were to be collected at six different locations at each house: one just outside the front and back entryways, two at different locations on the foundation, and two at different locations on the property boundary. The data provided for multi-element analysis were obtained for most of the vacuum dust and soil core samples collected during the pilot study. Only element concentrations (/2g/g) were analyzed for this report. Element loadings (/Ag/ft 2 ) were also measured for dust samples, but were riot considered in this analysis. Table 1 contains a description of the acronyms used in tables and figures to denote building components (referred to as “sample types”) . Listings of the raw element concentration data are displayed in Tables A-la through A-if of Appendix A by house. For each house, concentrations for each of the eleven elements are displayed by sample medium, building component, location, and sample ID. House number and sample ID uniquely identify each sample. When samples had determinations above the calibration range for a particular element, the maximum detectable concentration for the element is reported. (The maximum detectable concentration depended on the dilution factor of the sample.) These samples are identified by a superscript “a” in the Appendix tables. Univariate and multivariate outlier detection tests were applied to these data. The outlier analyses and the results of these analyses are documented in Appendix B. Lists of the potential outliers were sent back to the laboratory for verification. Most results for these samples were confirmed as originally reported. The one instance where an error was reported is documented in the footnotes to Table A-lb. 3 ------- Table 1. abbreviations for Sample Types Used in Tables and Figures Media Mnemonic Component Vacuum Dust Samples ARD BRU EWY (-I) FLR WCH WST Air ducts Bed/Rug/Upholstery Entryway (—Inside) Floor Window Channel Window Stool Soil Samples BDY EWY (—0) FDN Boundary Entryway (-Outside) Foundation Results for seven dust samples were excluded from the analyses. One of these samples was dropped in the laboratory (sample 12 in house 19) . Sample 7 in house 19 was excluded from the analysis since the cadmium result was greater than the upper calibration limit of the measuring instrument. For four of these remaining five samples, only lead concentrations were available due to calcium interference: samples 9, 3, and 17 in house 19, and sample 19 in house 43. Finally, sample 12 in house 51 was excluded due to sampling problems; the cartridge filled with sawdust prior to completion of the sample collection. 2.0 ANALTSIS RESULTS The analysis is divided into three parts corresponding to the three major objectives introduced above. Section 2.1 contains a characterization of the concentration levels of the different elements in the various sample types. Section 2.2 describes the estimated effects of abatement and renovation, and Section 2.3 examines the relationships among the elements and sample types. 4 ------- 2.1 CHARACTERIZATION OF ELE) NT LEVELS Due to the general lack of room level effects found in the analysis of the CAP pilot lead data, the basic experimental unit considered in the multi-element data analysis is the house. House geometric mean concentrations of the eleven elements were the basic quantities used in the statistical analyses. These are tabulated in Table A-2 of Appendix A by sample type and house for each of the eleven elements. For easy reference, Table 2 displays the abatement and renovation history of each of the six houses sampled. (Renovation is described later.) Table 2. Abatement and Renovation History by House House Interior Abatement History Exterior Abatement History Renovation 17 19 33 43 51 80 Abated: Removal Unabated Unabated Abated: Removal Abated: E/E Abated: E/E Abated: E/E Unabated Unabated Abated: Removal Abated: Removal Abated: E/E Partial Full Levels of each of the eleven elements observed varied by sample type. Figures la through 1k display geometric mean sample concentrations by house and building component for lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc, respectively. These figures display all the data considered in the analysis. Mean sample concentrations for each house are plotted with different symbols. The grand means over all houses are plotted with a circle and connected by a solid line across sample types. Note that the last three sample types in each plot represent soil samples, while the other sample types represent dust samples. 5 ------- 0 .. 8 10000 1 100 10 * z z V x + + , Sample lype House L.e er4 + + + 17 ) X 19 S 33 0 0 0 43 V V V 51 Z Z 80 00 99 Figure la. Lead Concentration vs. Sample Type (Geometric House Mean). 100000 jQ 0 C 10000 C 8 E E 1000 ______________________________ Sample Type House (.egond + + 17 K K K 19 33 0 0 0 43 V V V 51 Z Z 7 80 °°° 99 Figure lb. Aluminum Concentration vs. Sample Type (Geometric House Mean). V V V x V * * * + * + 0 * 0 V z 6 ------- C 0 . 8 E x - x + a w V t $ / / Sample Type House Legend 17 ‘C ‘C ‘C 19 • S 33 0 0 0 43 V V V 51 2 2 2 80 000 99 Figure ic. Barium Concentration vs. Sample Type (Geometric House Mean). — 1000 + o + 100 + I- 1: N , 4 4 /O Sarriple Type Hou9e Legend 17 ‘19 - 33 C 0 43 51 = = 80 99 Figure id. Cadmium Concentration vs. Sample Type (Geometric House Mean). * z + V 0 0 + + x i o u z x + x 7 ------- 1000000 3 C 100000 0 . icooo E 0 . o 1000 4 , ’ Sample Type House Legend ‘17 x X X 19 33 0 0 0 43 V V V 51 2 2 Z eo - - 99 Figure le. Calcium Concentration vs. Sample Type (Geometric House Mean). 1000 C 0 . * * 100 z x # Sample Type House Legend 17 X X 19 33 0 0 0 43 V V V 51 Z Z Z 80 e-e-e 99 Figure if. Chromium Concentration vs. Sample Type (Geometric House Mean). V x + V 8 ------- + Sample e HouseLegend 17 xxx 9 *5533 0D043 VYY 5 1 22250 e.e-e99 Figure 1g. Magnesium Concentration vs. Sample Type (Geometric House Mean). 1 C 2 100 + ‘ ° Sample Type House Legend 17 x X X 9 S 33 fl 0 0 43 Y V V 51 2 Z 2 80 99 Figure lh. Nickel Concentration vs. Sample Type (Geometric House Mean). 0 x z z 1 z a 0 9 ------- lcEjocP3 1 xc + 0 + + 1 _______________________ Sample l .pe House Legend 17 x X X 19 • S 33 0 0 0 43 Y Y 51 Z 2 Z 80 a-0a 99 Figure ii. Potassium Concentration vs. Sample Type (Geometric House Mean). C 0 10,, ,t 4 /’° — Sample jpe House Legend + 17 X X X 19 * * 33 0 0 0 43 V V V 51 Z Z 2 80 -- 99 Figure lj. Titanium Concentration vs. Sample Type (Geometric House Mean). 0 x * 0 * 0 + 100 + 10 ------- 0 .- . 100000 10000 1 Ilyt * * a z V F, Sample Type House Legend 17 x X x 19 • 33 0 0 0 43 ‘ 51 Z Z Z 0-0-0 99 Figure 1k. Zinc Concentration vs. Sample Type (Geometric House Mean). z 0 x z * 1]. ------- As can be seen in the figures, the highest geometric mean concentrations were observed for calcium in the indoor samples. For the outdoor samples, the highest levels were observed for aluminum. Of the different components sampled, lead concentrations were highest in air duct, window stool, and window channel samples (Figure la) . Levels of barium and zinc appear to be similar to levels of lead across sample types. On average, titanium was the least variable of the eleven elements within each sample type. For each of the elements except titanium and aluminum, dust samples taken from floors and entryways had similar concentrations. However, the concentrations for these two elements were higher for entryways on average than for floors. The levels of aluminum and titanium observed in entryway dust samples were more consistent with those observed in soil samples. This could indicate that soil is being tracked into the homes through the entryways, or it could be a reflection of the presence of these elements in the construction of the entryways. Levels of aluminum and titanium were also high in window channel samples. The highest mean chromium concentration was observed in house 33 for regular floor dust samples and entryway dust samples. The entryway soil samples from this house also had high chromium concentrations. The individual dust and soil samples obtained from the back side entrance to this home and a floor dust sample collected from the adjoining room (kitchen) had the highest chromium concentrations observed in the study (see Table A-lc), suggesting a possible relationship between exterior and interior chromium levels. In regard to zinc, there were two exceptionally high zinc concentrations observed on window channels and one high concentration on a window stool. However, each of these three measures came from different houses. 12 ------- When grouping the profiles in Figures la through 1k based on similarity, three groups of elements are formed. Lead, barium, and zinc seem to have similar contours and comprise one group. Aluminum and titanium make up a second group, while cadmium, calcium, and chromium make up the third group. To quantify the degree of variation in the concentrations of each element across sample types, an analysis of variance was performed on the geometric means plotted in Figures la through 1k. The results of this ANOVA are summarized in Table 3. For all elements except potassium and chromium, the differences across sample types were statistically significant. The strongest differences were seen for magnesium and calcium, with lower levels observed in soil than in dust. Table 3. Results of Analysis of Variance to Test for Significant Differences Among Sample Types, by Element 1enent Root sean Squared Error E’ value P value Comment Pb 1.14 4.47 .0006 Al 0.48 6.55 .0001 Ba 0.95 3.83 .0019 Cd 1.01 5.54 .0001 Ca 0.67 9.71 .0001 Soil all lower than dust Cr 0.78 1.59 .1570 Insignificant differences Mg 0.48 31.27 .0001 Soil all lower than dust, EWY lower than FDN Ni 0.77 4.83 .0003 K 0.74 0.55 .8096 Insignificant differences Ti 0.38 8.44 .0001 Zn 0.76 16.40 .0001 ARD, WST, WSL higher than rest 13 ------- Also included in Table A—2 are indicators of the primary method of interior and exterior abatement for each house. A “U” indicates that no abatement was performed in the house because no significant lead-based paint was present, an “R” indicates that the house was abated primarily by removal methods, and an “E” indicates that the house was abated primarily by encapsulation! enclosure methods. Table A-2 also contains the number of samples for which concentrations were determined for all eleven elements. Any sample in Tables A-la through A-if for which at least one element had a missing value was not included in the Table A-2 summary. Grand geometric mean concentrations for each element by sample type are displayed in Table 4. These were obtained by taking the geometric mean of the entries in Table A—2 across all houses for each sample type and element. Thus, each house where a sample was taken (for a particular sample type) is given equal weight in these averages. These grand means are plotted in Figures la through 1k by the circles connected by a solid line. Each geometric mean is followed by its log standard deviation. This represents a measure of the between—house variation for that response without controlling for abatement or renovation effects. 2.2 ABATE NT P ND RENOVATION EFFECTS 2.2.1 Abatement and Renovation Effects by Element The impact of abatement and renovation on the multi- element data was assessed by fitting a statistical model containing both renovation and abatement effects to the data in Appendix A. The model fitted to data for each element was C = m + aI + rR + E j = 1,...,6 14 ------- Ui Table 4. Geometric Mean Concentration and Log Standard Deviation Across Houses by Sample Type No of Dust Sample Sample Units Loading Medium Type Sampled (mg/fl 2 ) Lead Aluminum Barium Cadmium Calcium Chromium Gao Mean Log Std. (pglg) 0ev. Geo Mean Log (pg/g) Std Dev Geo Mean Log (pgFg) Std. Day. Gee Mean Log (pg/g) Std Dev Gao Mean Log (pglg) Sid 0ev Geo Mean Log (pg/g) Std. Dev. Dust WCH WST ARD FIR BRU EWY-l 4 6 5 6 5 6 73783 4683 35203 5826 4155 7184 2128 097 658 120 771 031 260 081 152 072 314 091 12940 039 6266 036 7136 032 6331 030 6248 047 10761 0.37 1647 1.58 703 116 325 060 295 052 254 045 294 078 19 1 061 239 1.03 263 1.32 93 068 97 0.62 95 049 33730 023 53230 051 40465 061 25042 044 24598 051 32709 103 40.1 0.46 543 054 773 064 48.7 080 550 052 454 079 Soil EWY-O FDN BOY 6 6 6 208 090 209 087 126 079 16058 033 14491 0.40 11373 042 276 021 257 031 166 031 56 085 40 041 2.8 051 9814 040 9812 031 8576 020 40.8 067 287 028 236 031 Sample Medium Sample Type No of Units Sampled Oust Loading (mg/fl 2 ) Magnesium Nickel Potassium Titanium Zinc Gao Mean Log (p9/9) Std Dev Gao Mean Log (pg/g) Std. Dew Geo Mean Log (p 919) Std. 0ev Geo Mean Log (p9/9) Std. Day. Geo Mean Log (pglg ( Std 0ev Oust WCH WST ARD FIR BRU EWY-l 4 6 5 6 5 6 737 83 4683 35203 5626 4155 71 84 5553 0 32 4807 029 3877 042 3222 025 3094 029 4419 040 24.0 035 380 037 407 117 278 060 450 102 207 0.36 2651 0444 2818 067 4260 036 4311 070 4046 089 4045 0.67 496 0 27 376 013 262 038 199 029 191 057 351 0 33 3226 1 07 1939 066 4458 098 770 039 656 070 722 049 Soil EWV-0 FDN BDY 6 6 6 574 016 1054 066 636 039 139 074 114 027 97 030 4069 026 3476 032 3504 033 482 023 421 024 372 026 296 037 372 035 178 046 ------- where C represents the observed (arithmetic) average log- concentration in house j, m represents the average log-concentration in unrenovated unabated houses, a represents the added effect of abatement, I = 1 if house j was abated 0 if house j was an unabated house, r represents the added effect of a full renovation, R is the degree of renovation house j was undergoing at the time of sampling (see below), and E represents house—to-house variation [ louse 51 was assigned an R) value of 1 indicating “full renovation” and House 19 a value of 0.5 indicating “partial renovation”. The other four houses were assigned R values of zero, indicating that no renovation was being performed. In the analysis of the lead data, the method of abatement (E/E or removal) was also considered as a factor in the statistical model. No significant effect was found; and therefore, this effect was not included in the above lead model applied to all elements. Estimates of the model parameters are reported in Tables 5, 6, and 7. Table 5 contains estimates and log—standard errors of the geometric mean concentration of each element in unrenovated, unabated houses, by sample type. Tables 6 and 7 contain estimates and standard errors of the multiplicative effects of renovation and abatement, respectively, by sample type. In Tables 6 and 7, a multiplicative effect of 1.0 implies no effect. A multiplicative effect less than one indicates that lower levels were observed in renovated (abated) houses, while a multiplicative effect greater than one indicates that higher 16 ------- I-i —3 Table 5. Model Estimates and Log Standard Errors of Geometric Mean Concentrations in Unrenovated Unabated Houses Sample Medium Sample Type , Houses Lead Aluminum Barium Cadmium Calcium Chromium Gao Mean Log Std. ljig/g) Err Gao Mean Log (jigIgl Std. Eu Gao Mean Log lpglg) Std. Err. Gao Mean Log (pg/g) Std. Err. Gao Mean Log (pglg) Std Err Geo Mean Log lpg/g) Std. Err. Dust WCH WST ARD FLA BRU EWY-l 4 6 5 6 5 6 7238 0 64 226 1 17 875 041 102 033 117 045 96 019 13346 0 54 5808 039 5341 036 7687 030 11954 039 14146 034 7058 1.95 478 1 11 216 068 313 031 163 049 255 0.47 29 7 0 07 214 089 360 184 191 059 254 034 130 057 34866 0.37 57057 012 53114 068 20998 025 18230 018 25873 035 39 0.72 87 046 46 069 141 036 69 012 109 063 Soil EWY-O FON BDY 6 6 6 63 043 102 0.89 53 081 22668 010 18568 033 11492 0.44 261 015 252 037 128 030 39 081 36 048 21 057 13126 036 13395 027 9977 025 60 068 32 018 21 033 Sample Medium Sample Type # Houses Magnesium Nickel Potassium Titanium Zinc Geo Mean Log (pglg) Std Err Gao Mean Log (pgig) Std. Err. Gao Mean Log (pglg) Sici. Err. Geo Mean Log (pg/g) Sid Err. Gao Mean Log (p919) Std Err Dust WCH WST ARD FLR BRU EWY-l 4 6 5 6 5 6 4237 045 4501 035 2719 050 3337 025 3558 039 4400 0 23 179 050 313 041 352 027 412 069 176 064 24 6 043 2563 072 2784 077 5553 041 4184 046 6723 092 5575 0 70 656 033 370 013 188 044 222 033 387 057 444 0 28 13783 035 1229 037 16504 067 5552 040 4478 094 439 1 0 40 Soil EWY-0 FDN BDY 6 6 6 535 011 1175 043 703 045 133 081 149 020 847 021 4955 012 4458 019 3500 033 601 008 443 026 338 022 1831 019 2695 029 1208 052 ------- H Table 6. Estimates and Log Standard Errors of Multiplicative Renovation Effects Sample Medium Sample Type Lead Aluminum Barium Cadmium Calcium Chromium Log Std Effect Err Log Effect Std Err Log Effect Std. Err. Log Effect Std. Err. Log Effect Std. Err. Log Effect Sid Err. Dust WCH WST AED FIR BRU EWY-l 045 062 134 1.57 051 1 32 467 0.12 1708 164 487 004 062 044 096 024 281 1.05 066 0.10 014 120 057 013 0 1 570 0.27 140 737 366 035 011 501 192 025 025 032 001 021 091 043 27 17 059 039 017 092 084 037 084 0.21 283 002 1 72 366 255 007 1045 026 980w 014 061 078 043 024 989 384 044 015 319 011 056 045 Soil EWY-O FON BDY 2 12 021 229 091 1 97 067 0.50 001 049 013 057 0.22 072 0.03 078 016 093 0 10 043 075 078 027 086 037 054 0 15 077 009 081 006 038 053 057 004 071 0 12 Sample Medium Sample Type Magnesium Nickel Potassium Titanium Zinc Log Effect Std Err Log Effect Std. Err Log Effect Std Err Log Effect Std Err Lag Effect Std, Err Dust WCH WST ARD FIR BRU EWY .l 1.14 030 127 014 352 1 98 138 007 088 1 22 221 006 1.10 038 159 019 79 23 0.58 084 054 141 04 323 109 021 072 078 052 067 031 1 34 028 025 004 6 74 039 055 104 016 085 002 348 1 55 074 012 0 18 2 61 058 009 041 018 047 016 001 3.61 145 018 3 35 7 14 191 018 Soil EWY-0 FDN BDY 136 001 027 021 195 014 044 074 063 005 062 005 056 002 052 004 063 013 062 001 072 008 065 005 125 004 090 009 124 030 9ndicates effect was signfucant at p 05 level ------- Table 7. Estimates and Log Standard Errors of Multiplicative Abatement w Effects Sample Medium Sample Type Lead Aluminum Barium Cadmium Calcium Chromium Log Std Effect Err Log Effect Std Err. Log Effect Std Err Log Effect Std. Err Log Effect Std. Err. Log Effect Sid. Err. Dust WCH WST ARD FLA BRU EWY-l 026 062 445 103 091 022 227 008 0.96 027 325 003 113 044 109 016 1 36 0 17 087 007 047 020 082 009 021 570 293 092 1 42 061 136 007 161 032 208 016 0.82 001 211 060 068 4 53 041 0.26 0.27 0.15 067 024 102 021 06P 001 058 0.61 092 005 1 11 004 0.60 009 119 078 068 016 1 60 064 027 010 056 002 033 030 Sod EWY .0 FDN BDY 451 014 213 060 242 044 077 001 0.90 008 114 0.14 122 002 1.13 010 149 007 241 049 130 018 158 0.25 081 010 069 006 092 004 081 034 107 002 123 008 Sample Medium Sample Type Magnesium Nickel Potassium Titanium Zinc Log Effect Std Err. Log Effect Std Err Log Effect Std Err Log Effect Std Err Log Effect Sod Err Dust WCH WST ARD FLR BRU EWY-l 1.37 030 1 01 009 1 46 0 33 084 005 081 020 075 004 144 038 1 12 012 062 0 10 059 036 210 054 075 0.14 117 078 1 30 044 0 78 0 22 169 016 072 112 088 036 068 016 109 001 1 41 026 095 008 041 044 086 006 019 018 263 010 0 25 060 142 012 155 119 165 012 Soil EWY-O FDN BOY 0 99 001 138 014 088 009 1 46 049 080 003 137 003 0 92 001 088 003 1 17 008 086 000 105 005 123 003 1 89 003 168 006 155 020 9ndicates effect was significant at p= 05 level ------- concentrations were observed in renovated (abated) houses. Those multiplicative effects that were significantly different from one at the 0.05 significance level are denoted by asterisks. Figures 2a, 2b, and 2c display block charts of the estimates in Table 5 (portrayed on a log scale) . A distinction between sample types was observed in the average levels displayed in these figures. Therefore, the sample types were purposely presented in three groups. Figure 2a displays the estimated average log—concentration in unrenovated, unabated houses for air ducts, window stools, and window channels. Figure 2b displays the corresponding estimates for bed/rug/upholstery, entryway, and floor samples. Figure 2c shows the estimates for soil samples (boundary, entryway, and foundation) . Air ducts, window stools, and window channels typically had the highest baseline levels of lead, calcium, and zinc. Soil samples had the lowest concentrations of these elements. Notice the relatively similar behavior of these estimates across the different elements within each of the three sample groups. For example, the ratio of lead to aluminum is smallest for soil samples, and largest for window channels, window stools, and air ducts. Another distinction was observed in the relationship between lead, titanium, and zinc. Figure 2a depicts a lower titanium level than lead or zinc for air ducts and window channels. On the other hand, levels portray a general rise as one moves from lead to titanium to zinc for floors, entryways and bed/rug/upholstery samples in Figure 2b. Finally, in Figure 2c, titanium was the element with the highest concentration amongst lead, titanium and zinc, in each of the soil samples. In trying to identify the source of dust on floors, the relationship among levels of the different elements for window stools appears more similar to those for floors, entryways, and bed/rug/upholstery samples than to those for window channels and 20 ------- N C Figure 2a. Block Chart of Estimated Average Log-Concentration in Unrenovated, Unabated Units for Window and Air Duct Dust Samples. t o F-a Pb Ba Cd Ca cr Mg NI K 11 Zn ------- Con 7(I j /1/I li/I iii /I’I iI A / 8.96 5.76/ 2.951 9.95 4.96 8.11/ 3.72 8.34 5.40 6.32 / III / IU I /1 / 4.76 9.30 5.00 324 9.81 4.23 8.18 2.87 8.81 5.96 6.10 I 4.57 9.56 5.54/ 2.57 102 4.60 8.39 / 3. 8.63 6.10 6.08 Pb M Ba Cd Ca Cr Mg NI K 11 Zn Figure 2b. Block Chart of Estimated Average Log-Concentration in Unrenovated, Unabated Units for Floor and Textile Dust Samples. ------- Con 7 fj / hi / iii j I / 4.14 1110.0 5.56 / 1.35 9.48 / 4.09 6. / a89 8.51 6.40 5.21 / FON / /1 /1 / 4.63 9.83 5.53 128 9.50 3.45 7.07 2.70 8.40 6.09 5.60 6W I 4.09 9.39 4.86 / 077 9.16 / 3.11 5.38/ 2.18 8.17 5.89 484 Pb PJ Ba Cd Ca Mg NI K 11 Zn B n 1 Figure 2c. Block Chart of Estimated Avrage Log-Concentration in Unrenovated, Unabated Units for Soil Samples. ------- air ducts. This is likely a reflection of the general composition of these dust samples. Figure 2a indicates that the window channel samples have especially high concentrations of barium and lead relative to the concentrations of the other elements. In this manner, window channel samples seem to differ from the other types of samples. Close attention should be given to the log standard errors of the estimates in Tables 6 and 7. Most of these are very large in comparison to the (logarithm of the multiplicative) estimates. Note that a total of 198 statistical tests were performed in the analysis supporting the results in Tables 6 and 7. Each test was performed at the 5% level. Therefore, even if there were no effects of abatement or renovation on any of these element concentrations, we would still expect 9 or 10 sample type/element/factor combinations to be significant. A total of 18 combinations were found to be significant. Of these, calcium was involved in five cases, lead was the element involved in four cases, potassium was involved in two cases, while aluminum, cadmium, chromium, magnesium, nickel, titanium, and zinc were each involved in one case. Entryways were involved in 9 cases of significance (5 soil and 4 dust), floors in 3 cases, and window stools in two cases. One case of significance was observed for air ducts, bed/rug/upholstery, window channels, and foundations. Thus, although more cases of significance were observed than would be expected if there were no real effects, the number of statistically significant results was small relative to the number of tests performed. This, along with the limited data set associated with the pilot study, makes it difficult and perhaps inadvisable to draw general conclusions from the estimates reported in Tables 6 and 7. 24 ------- 2.2.2 abatement and Renovation Effects Across Elements A principal components analysis was performed to determine whether the relationships in element concentrations among the houses (or houses with a similar abatement/renovation history) were similar for the different sample types. This analysis is an attempt to simplify the interpretation of the data by reducing the number of elements characterized from eleven to perhaps two or three “element classes”. These element classes represent weighted averages of the eleven elements. Ultimately, this may provide insight into the following source-assessment question: “Where does the lead in household dust come from?” This analysis, was performed on mean log-concentrations for each element and house by sample type. The purpose of this analysis was two-fold. A principal components analysis provides a mathematical tool for estimating the approximate dimensionality of the responses. Also, plotting the higher-order principal components against each other affords an objective means of identifying clusters of houses with similar dust and soil element compositions. The ultimate goal is a reduction in the complexity of the multivariate data analysis. Principal component analyses can be performed based on either correlations or covariances. Analyses based on correlations standardize the range of each of the elements’ concentrations. This prevents the most widely fluctuating elements from dominating the analysis and gives equal attention to all variables regardless of their range. Covariance-based analyses leave all element concentrations in their original scale. Since the scales observed varied substantially by element, and a priori there was no reason to weight more heavily the elements with greater absolute variation, the principal component analyses were performed based on correlations. 25 ------- Table 8 displays estimates of the first two principal components (i.e., the two principal components explaining the most variability in the data) by sample type, followed by the cumulative proportion of total variation explained by these components. Figures 3a and 3b display plots of the relationship between the first and second principal components by sample type. Figure 3a is for dust samples; Figure 3b is for soil samples. Houses are distinguished by different plotting symbols in these figures. Refer to Table 3 for a synopsis of abatement and renovation history of these houses. For many of the sample types, more than 70% of the total variation is explained by the first two principal components. There was a similar weighting pattern applied to the elements for floor and entryway dust and entryway soil samples. The weights are assigned to the different elements so as to maximize the variation. Therefore, if two elements are negatively correlated, then the weights of the high-order principal components of the two elements will likely be of opposite signs. For example, as will be seen in Section 2.3, aluminum and calcium concentrations are negatively correlated in entryway dust. Table 8 shows that their coefficients in the first principal component are of opposite sign for entryway dust. Obviously, when considering so many elements, it is impossible for this relationship between correlation and principal component coefficients to hold for all pairs of elements. If there were patterns in the relationships of these eleven elements affected by abatement or renovation history, then homes with similar histories would expect to be clustered in Figures 3a and 3b. The figure allows inspection for such relationships separately by sample type. However, comparing the proximity of the houses to each other in Figures 3a and 3b, there do not seem to be any consistent groupings of houses across 26 ------- Table 8. Principal Componente for Unit Mean Log-Concentration by Sample Type t’ ) — 3 Sample Medium Principal Component Component Principal_Comoonent_Coefficients Pb Al Ba Cd Ca Cr Mg Ni K Ti Zn Cumulative Explained Variability Dust ARD 1 2 0 15 -0.14 0.29 0.41 0.11 -0.49 -0 23 0.43 0.37 -0.08 0.45 0.08 0.40 0.25 0.29 -0.10 -0.27 0.46 0.40 0.28 -0.14 0.11 0.44 0.71 BRU 1 2 0.40 0.22 -0 33 0 39 0.25 0.00 -0 17 0.37 0.40 0.26 0.33 0.37 -0.08 0.48 043 0.16 -031 0.13 -0.27 0.37 -0.05 0.21 0.44 030 EWY-l 1 2 -0.32 0.16 0.38 0.28 0.22 -047 0.28 0.34 -0.39 0.24 0.29 0.50 -0.31 0.35 -0.10 -0.16 0.31 -026 0.37 0.19 -0.23 -0.01 0.47 0.67 FLR 1 2 -0.44 0.12 0.32 0.38 0.30 -0.34 0.29 0.37 -0.43 0.24 0 29 0.37 -0.23 0.22 0.01 -0.26 0.26 -0.25 0 24 042 -0.27 0.20 0.36 0.68 WCH 1 2 0.29 0.36 -0.26 0.33 0.38 0.17 0.13 042 0.34 -0.17 0.30 -0.22 -0.40 -0.02 0.17 -0.47 -0.31 028 0 38 0 12 0 24 0.41 0.57 088 WST 1 2 0.41 0.02 -0.37 0.10 0.43 0 14 -0.19 0.41 -006 -0 53 0.33 0 12 -0.34 0.07 017 -0.21 -0.28 0.42 0.11 045 0.35 0.29 0.45 0.74 Soil BDY 1 2 -0.10 0.46 0.43 -0.03 0.22 0.41 0.08 0.44 0.19 -0 36 042 -0.02 -0.12 -0.24 0.42 -0.02 0.42 000 0.42 -0.02 -001 0 48 0.48 0.84 EWV-0 1 2 -0.36 0.29 0.40 -013 0.15 019 0.22 0.58 0.29 -007 0.33 0.21 -0.25 0.14 0.24 0.52 0.37 004 0.36 -0.16 -0.25 0.40 0.52 0.70 FDN 1 2 -0.33 0.29 0.38 0.13 0.16 0.45 -0.17 0 34 0.32 -0.28 0.36 0.13 0.33 0.25 0.36 -0.18 0.39 000 027 0 37 -0.06 0 50 0 57 0 85 ------- WCHI vZ ____________ WST I N + ARDI p. + o a * x z ____________ FLRI S a “ ___________ BRU I N * X x a Z ___________ EWY-Il a 1 ’ . x HOUSE +++ 17 XXX IS *** 00043 flY 51 ZZZSO Figure 3a. Plot of First Two Principal Components of Mean Log- Concentrations for Dust Samples. BDY I z N c i + X EWY-Ol + V a X * FDN I N 0 V * 0 S I + X HOUSE 17 XXX 19 ***33 00043 VVV 5 ZZZ$ Figure 3b. Plot of First Two Principal Components of Mean Log- Concentrations for Soil Samples. 28 ------- sample types. Substantive conclusions would require data from more than six houses. 2.3 RELATIONSHIPS AMONG THE ELEMENTS 2.3.1 Bivariate Relationships (Correlations) Displays portraying the bivariate relationships among the eleven elements are provided in Figures 4a through 4i. For each sample type, average log-concentrations for each house are plotted for each pair of elements. Ellipses are drawn on each plot that represent 95 percent of the estimated bivariate distribution. Those plots for which the ellipse is narrow represent pairs of elements for which there was a strong observed correlation. Pairs of elements which are negatively correlated have an ellipse with major axis running from upper left to lower right. The magnitude of the correlation can be inferred from the shape of the ellipse by comparing it to the key in Figure 5. On the plots in Figures 4a-4i, each house is identified with a different symbol. This allows one to determine whether certain houses have similar characteristics with respect to the various elements and/or sample types. The strongest relationships among the elements across houses were observed in foundation and boundary soil samples (Figures 4h and 4i) . These correlations were strongest among aluminum, chromium, nickel, potassium, and titanium. Strong relationships were also observed among lead, calcium, chromium, and nickel in samples taken from bedcover/rug/upholstery (Figure 4e) . Lead concentrations were most frequently correlated with zinc concentrations. High correlations were also observed on window stools between lead, titanium, barium, and zinc (Table 4b). A slightly different categorization of sample types could be made based on the patterns observed in these 29 ------- 6 ? 6’ c N 6 Bs 6J g g c ‘ 9 € 9 9 c c c ;: c c ç 9 E c 3 N E 7 c c / c i: K 9 q 9 6’ c € ® g 7 c 3 Q Il \ @ / & 9 c ; 3 ? c 6P / 6 ; c c ’ / c c c y \ c M ç y \ c , g N , c c £ K 6 / \ , , c ? 2 Q ? Figure 4a. Window Ch2nnel House Mean Correlation Scatterplot. Figure 4b. Window Stool House Mean Correlation Scatterplot. c c i c c ; N 9 c / c c c / Q: 6 / 9 c , c c / c 9 c ct & Q: c c 9 / c Figure 4c. Mr Duct House Mean Correlation Scatterplot. Figure 4d. Floor House Mean Correlation Scatterplot. House Legend: * = 17 0=19 +=33 X=43 Z=51 Y=80 — v ; c &% c; p P1 K J —7 30 ------- / 6’ g ; ftJ c ‘ c 3 3 9 c9 c 9 c ; 9 , 6’ G 6’ c) a’ 6’ a’ c 3 c 7 ; c 9 6 6’ 6’ () P1 ( c 3 £ K g 9 c 3 G c £ c Figure 4e. Bedcover/Rug/Upholstery House Mean Correlation Scatterplot. Pb ( (9 ( ( ) ( N (9 6’ ( I Q 9 , , c 5 °. c ; ci:; c Cd / , D / c;;’ c; 3 c 9 , c P1 ct I c 9 3 : K ! Figure 41. Entryway Dust House Mean Correlation Scatterplot. X=43 Z=5i. Y=80 c % & — N 9 3 s c 3 6’ / 9 3 c13 D £ ; (9 , & cV & ? c ® 2 4) D % c E G / ; ‘ 9 N 6’ e 6’ Y V 6’ K ? , 9 3 s !3 6’ CD :D c % Figure 4g. Entryway Soil House Mean Correlation Scatterplot. Pb c 9 \ \ c N c ‘ ‘ I / @ a © © / ( 7 Cd ) ) ( ( \ c Cd ) if ( ( c / if @ ( if ) ) if I 3 ( if ) P1 if ( 9 ( if 9 if ci ‘ if g if K ( ( ;, c c Figure 4h. Foundation Soil House Mean Correlation Scatterplot. House Legend: * 17 0 = 19 + = 33 3]. ------- Pb (9 (9 ( (? ( ) 6’ ; c & / 6’ / 6’ cQ 7 L I ‘ cV 3 g I / c cc c ç c9 cc c , c , 6’ / c c ç ( 6’ (g? ( 7 6’ ( F / ( 3 / ( ) 9 6’ @ 6’ K 6’ ( ) , cg cD c / / 6’ g g , c Figure 4i. Boundary Soil House Mean Correlation Scatterplot. HouseLegend: *j7 019 +33 X43 Z51 Y80 90% 60% 30% 0% 0 0 0 0 Figure 5. Key to Relation Between Shape of Ellipse and Observed Correlation in Figures 4a Through 4i. scatterplots. Relatively consistent sets of bivariate plots were observed for the following groups of sample types: floor, interior entryway, and exterior entryway; boundary soil and 32 ------- foundation soil; and window stool and window well. Air ducts and bedcover/rug/upholstery samples do not appear similar to any of the groups mentioned nor to each other. These groupings of the sample types do not appear particularly surprising although one might have expected exterior entryway samples to be more like the other two soil samples than like interior floor dust samples. The floor, interior entryway, and exterior entryway group displays consistent, strong bivariate relationships between aluminum and titanium; cadmium and chromium; and barium and potassium. As introduced above, the boundary and foundation soil group displays the strongest bivariate relationships, suggesting consistent correlations between lead and calcium; aluminum and chromium; nickel, potassium, and titanium; chromium and nickel; potassium and titanium; and nickel and potassium. The window channel and window stool group has consistent bivariate relationships between lead, barium, and zinc; chromium and magnesium (negative correlation); and titanium and zinc. 2.3.2 Multivariate Relationships (Principal Components) For the estimated model parameters displayed in Tables 5, 6, and 7 (average log-concentrations, in unrenovated unabated houses, increments in log-concentration associated with renovation, and increments in log-concentration associated with abatement), a second principal components analysis was performed on these estimated model parameters across the nine sample types. The purpose of this analysis was not only to identify consistent patterns in the composition of dust across different sample types (unrenovated, unabated house analysis), but also to determine whether abatement or renovation impacts different components in different ways. The numerical results of the principal components analyses and plots of the first two principal components are 33 ------- displayed in Table 9 and Figure 6. Table 9 displays estimates of the coefficients for the first two principal components followed by the cumulative proportion of total variation explained by these components. Figure 6 displays the relationship between the first two principal components (the orthogonal directions in which the greatest variability were observed) The first two principal components generally accounted for at least 68% of the total variability in the model parameter estimates. This means that although there were eleven elements measured (lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc), most of the variation among the nine sample types occurred within a two- dimensional space (i.e., two linear combinations of the eleven element concentrations) For averages in unrenovated, unabated houses it can be argued that the three soil sample types are grouped into one cluster; floor, entryway, window stool, textile, and air duct dust sample types form another cluster; and window channels stand alone. For the renovation effect, all samples are grouped into one cluster except for air ducts and textiles, which stand alone. One must recognize that air ducts and textiles were not sampled in the fully renovated house. Therefore, the estimated impact of renovation on these sample types is less meaningful than on the other sample types which were sampled in the fully renovated house. For the abatement effects, there were no clear clusters or outlying sample types, but the three soil sample types appear close together in Figure 6, and interior entryway samples were right on top of exterior entryway samples, with floor dust samples nearby. This may be an indication that even after abatement, the composition of the soil near the foundation and entryway is similar to that of the soil at the boundary. 34 ------- U ’ Table 9. Principal Components for Unrenovated, Unabated Home Averages, Abatement Effects, and Renovation Effects Coefficients are applied to the estimated parameters for each sample type to obtain maximum spread among sample types in two dimensions Response Principal Component Principal_Component Coefficients Cumulative Explained Variability Pb Al Ba Cd Ca Cr Mg NI K Ti Zn Unrenovated Unabated Unit Means 1 020 -037 0.17 0.43 0.41 0 15 037 036 -009 -017 0.32 040 0 71 2 048 0 20 0 48 0.04 -O 00 -0 32 -000 -0.28 -0.27 043 0 25 Abatement Effect 1 034 -0 37 0 30 0.11 007 -0.43 -0 43 0 16 009 -023 042 0.36 068 2 035 029 0.31 0.31 -0.46 0.07 006 -0.34 0 10 044 0 22 Renovation Effect 1 002 040 0.43 -0.13 0.03 046 034 030 -022 040 -010 043 0 83 2 047 -0 22 0 13 -0 15 0 40 -0 01 -0 15 0 33 -0 37 -023 0 45 ------- + , x* a V * MTh * + 06 Oon oriiifl +‘ WOH xxx *** aaa D ORU ZZZ EWY—I * EWY’_O 060 FflJij 666 V’ Figure 6. First Two Principal Components for Each Building Component, Plotted versus Each Other for Unrenovated, Unabated Unit Mean Log-Concentrations, Renovation Effects, and Abatement Effects. Notice that the clusters apparent in Figure 6 (for the unrenovated unabated houses) are consistent with the groupings identified in Figures 2a, 2b, and 2c. One notable exception to this is that the window channel sample type appears to be somewhat removed in Figure 6 from the grouping identified in Figure 2. 3.0 CONCLUSIONS Based on the statistical analyses of the multi-element data, the following conclusions were drawn: 36 ------- Characterization of multi-element concentration 1. Of those elements analyzed, aluminum, calcium, and potassium had the highest concentrations in indoor dust and soil. 2. After controlling for abatement and renovation effects, concentrations of the elements provide for the following groupings of sample types: - air duct, window stool, and window channel dust - floor, entryway, and textile dust, and - foundation, entryway, and boundary soil. Effects of abatement and renovation on multi—element concentrations 3. Lead concentrations in dust and soil near the entryways of abated houses were three to five times the levels in unabated houses. The concentrations of lead in dust from floors and entryways of renovated houses were about five times those in unrenovated houses. 4. Calcium concentrations in the dust of renovated houses were significantly higher on window stools, floors, textiles, and entryways. This difference was tenfold for textiles and entryways. 5. Several other statistically significant effects were estimated for the remaining elements, but with little consistency across elements or across sample types. Relationships between element concentrations for sample types 6. Of the ten elements measured besides lead, concentrations of zinc were most positively correlated with lead, both within sample types and across sample types. 7. The strongest bivariate relationships among the elements were observed in boundary and foundation soil samples; three groups of sample types were identified as having similar bivariate relationships among many of the elements; floor, interior entryway, and exterior entryway; boundary and foundation soil; and window channel and stool. 37 ------- 8. A principal component analysis of estimated element concentrations in unrenovated control houses by sample type suggested similarities in dust and soil composition within the following groups: 1) exterior entryway, foundation, and boundary soil, and 2) floor, interior entryway, window stool, air duct, textile dust. The sources of lead in household dust still remain to be identified. The sparcity of data available for this analysis proved to be a limitation of this study. The following section suggests the potential value in performing a similar analysis on data collected in the CAP full study. 4.0 RECO * ENDATIONS FOR uxu E WORK In the pursuit of a solution to the problem of childhood lead poisoning, it is important to identify the sources of lead in order to best target its containment. The data used for this analysis were collected in a pilot study for a large scale investigation of the long-term efficacy of various abatement methods based on samples collected from six houses. The full CAP study, initiated one year later, involved 52 houses, 35 abated and 17 unabated, and would provide a greater amount of data to address this issue. Although fewer samples were collected at each house in the full study than in the pilot, samples were collected from similar locations in the full study, with additional dust samples collected outside entryways to provide a better means of relating interior dust lead levels to exterior lead levels. The data used in this analysis were collected from only a small handful of houses (six) in the Denver area. Analysis of these data was not expected to demonstrate significant relationships. Instead, it was used to determine sample sizes and test sampling protocols for the subsequent full CAP study. 38 ------- Use of the data collected in the full CAP study to perform analyses similar to those in this report would provide nine times as much data (52 houses) to characterize the source of lead in household dust, both in abated and unabated houses. 5.0 REFERENCES US EPA, 1995, “Comprehensive Abatement Performance Pilot Study, Volume I——Results of Lead Data Analyses”, EPA 747—R—93—007. Morrison, D., 1976, Multivariate Statistical Methods , Second Edition, McGraw-Hill. 39 ------- APPENDIX A SU) ARY OF )WLTI-ELE NT DATA A-i. Multi-Element Data Listing A-2. Geometric Mean Concentrations by Sample Type and Unit ------- Table A-la. CAP Pilot Study Multi-Element Data, House 17 m C is a -I is I-I Sample Identification Cc centratiori, WglgI Medium Component Location Sample ID Pb Al Ba Ca Cd Cr K Mg Ni Ti Zn Dust WCH WST ARD FIR BRU EWY-l KIT KIT BD1 BD1 LVG LVG LVG KIT BD1 KIT KIT BD1 BD1 BD1 LVG LVG 601 EWY EWY 07 06 14 16 36 39 40 09 19 01 03 11 12 13 31 32 18 20 21 114131 22083 726 85 337.99 50643 26955 33678 36344 71746 50 25391 37318 32803 22471 153 6369 6692 2816 25873 2677724 659556 16274 87 1252425 4475.87 1254895 976988 896632 8663.88 1694 694983 728784 926141 609359 5165.24 6462 19 513931 1024255 1022246 91487 43983 627 26 72482 37746 182144 217222 187 13 17304 742 184107 741.58 87534 6981177 44163 165.42 4338 3667 110304 22699.03 48002.71 39088.01 417287 29715 21150.79 2721952 163533 16881.18 14246 23113.58 15383.03 8765.93 33722.36 1389872 7081.12 19032.89 1225382 16548 39 b 1137 197 81 19129 3952 30686 14556 6572 61527 31 1339 2614 1457 874 1061 371 997 1958 11 48 4502 2357 35 77 3858 4287 4331 5083 4033 6485 1619 2935 4366 4271 2926 2596 2459 4385 365 3465 480513 3185688 3817 92 499182 880283 4923.04 6291.52 77438 578907 14419 1715868 1001167 1146905 1486837 987072 4597 17 809704 811838 8421 34 487308 845697 8035 08 735533 1091543 397775 637633 378481 373365 2724 395011 279445 224061 4176246 249427 1595 8 321003 228621 30933 2048 15916 23 06 222 18811 1684 27 12 2268 1963 13 1627 12044 455 3387372 22248 186 7684 273 2789 956.57 32289 551 82 36847 24343 626.99 50508 24546 29633 5507 10436 20734 18784 24252 1586 20868 849 2852 331 86 149234 173207 10045 28 422307 252174 130890 190958 516 53 3986045 502 133825 51621’ 28448 174851 48600’ 229 40 572.3 42553’ 620 35 Soil EWY-0 FDN BOY FRO BAC LFT BAC BAC IFT BAC IFT 22 23 24 26 29 26 21 28 704 36388 7024 694 6568 5222 7046 5636 2041234 1958558 2077997 17951 05 1821279 2670432 2021482 2505986 195.83 43975 198 82 261 98 1713 22099 18278 20569 1284944 14160.18 12213.25 11275 17 1173242 13088.59 825867 133344 275 24107 281 262 251 268 233 261 377 26894 4089 39 16 3796 4456 3848 4381 536142 45706 5407 94 4415 52 446055 639675 593693 587071 53998 61415 667 53 2568 3 296125 9843 500 102935 1507 23811 15 72 13 93 1429 171 1547 1642 48649 58248 421 58 39086 3849 69191 45442 6432 18052 49930’ 279 23 34543 29892 11563 17678 10848 analysis result was greater than upper calibration limit for zinc, reported value is a lower bound on the true Zn concentration assuming an instrument sample concentration of 5 pg/mL analysis result was greater than upper calibration limit for cadmium, sample excluded from data analysis C 0 z 0 C, CD 0 ------- Table A-lb. CAP Pilot Study Multi-Element Data, House 19 • Analysis result was greeter than upper calibration limit for zinc; reported value is a lower bound on the true Zn concentration assuming an instrument sample concentration of 5 pg/mL b ICP analysis hampered by calcium interference; no multi-element date reported sampla dropped in lab, therefore, no multi-element data reported Titanium Concentration received by Battelle on July 24, 1995 via fax from MRI Originally, concentration reported as 0 38 pg/g Sample Identification Concentrations_(pn/g) Medium Component Location Sample ID Pb Al Ba Ca Cd C i K Mg Ni Ti Zn Dust WCH WST ARD FIR BRU EWY-I BD I LVG BD1 KIT LVG BDI IVG LVG BD1 BD1 BD1 KIT KIT LVG 801 EWY EWY 17 04 16 36 09 19 01 03b 11 12’ 13 31 32 08 18 20 21 36788 7083 21527 17682 69 53 62441 18993 69 53 30115 . 4023 99.5 6794 481 99 48457 20107 18441 412958 776183 418735 . 894803 45633 . 5504.92 568566 425268 43303 680906 2901.15 8659.46 674203 7414 28117 20885 . 5851 17872 59805 . 83081 10288 53.14 694.67 19046 27511 5681 148864.4 7419087 9268482 6961023 177240 1997404 58480.23 927994 8142.32 9380468 37037.35 1395138 94780.78 414 3741 1696 . 2372 615 . 1949 1362 571 324 12 73 8.51 6.16 1008 5025 77.8 30.28 145.95 3606 . 113.58 15706 4494 41.9 186.6 81.44 4075 40.06 12028 24483 169326 309705 288897 . 247267 213681 22913 226931 1900 86 102431 539783 205037 . 1242288 405361 261933 . 510354 7937.28 . 336526 398515 291028 289751 4602 61 242759 689201 598681 . 1906 11631 4727 3129 3145 • 15209 30646 4322 4072 389 22 11161 3061 4764 41619 38527 16558 35142 129.78 157.26 16632 13606 14307 26468 10443 28962 24122 23135 205174 94377 146594 706.47 • 68325’ 152083 31554’ 26691’ 1967 25 34126 55109 58253 Soil EWY .0 FDN BDY FRO SAC FRO FRO LFT FRO LFT LFT 22 23 28 24 25 26 27 29 4969 4035 19653 4918 23839 98 17 4329 4416 12841.36 928405 31300.7 1020946 10529.04 10937.94 8343.79 80294 130.93 12833 40863 11556 22761 120.94 11587 110.3 1223328 13372.92 1513247 1260323 1245127 8323.19 1116584 11658.17 227 2.04 323 202 485 2.3 2.3 163 2366 1789 3425 1974 2781 24 6 1598 1526 343163 284254 698002 300539 318934 3432 85 34851 295139 49092 37028 98468 40253 37827 43045 151102 150823 1026 11.68 138 801 2097 8 91 658 649 3829 28455 75313 29468 37389 379 06d 25652 22281 16104 27844 281 14331 46134 160 67 10729 13044 0 C is 0 -I is 0 0 z 0 C ’) P. 0 0 0 0 — CD ------- Table A-ic. CAP Pilot Study Multi-Element Data, House 33 Sample Id e ification Concentrations_(ugig) Medium Component location Sample ID Pb Al Ba Ca Cd Cr K Mg Ni i i Zn Dust WCH WST ARD FIR BRU EWV-I LVG BD2 LVG LVG LDY BD2 LVG BD2 602 LVG LVG IVG KIT KIT LVG EWY EWY 17 04 14 16 36 09 19 01 03 11 12 13 31 32 18 20 21 7238 25 57488 17452 56192 58072 47655 160502 13475 18292 18867 12835 10682 11607 8819 11693 12802 8842 13345 86 704392 97397 804521 395714 803089 3552 490884 488063 1313019 1244336 13414.99 1361978 1323038 1195433 21715 21 1791001 7057 8 48848 59445 183116 5104017 20649 22492 35711 13885 29987 452.52 16689 28809 30061 162.54 225.8 29809 3486607 3734122 2687453 5583219 1552299 7669884 3678182 42255 4181808 2078874 2154272 2385941 1903319 20173.65 1822988 2095709 1585119 2966 1959 2474 1101 1006 1978 656 1305 4089 8891 6606 2081 3571 3295 2544 1294 3001 3905 1352 10078 8699 8583 5297 4067 9674 8523 18048 19026 14588 51597 67648 6906 94 18 52319 256344 59598 373399 335462 1512946 366559 841354 1830.23 120962 5104.15 5707.61 584624 598561 560286 6722.99 5796 35 582801 423708 414932 322294 443562 677991 337843 218899 325346 293791 317231 294908 406177 349118 366808 3558 28 5175 63 387388 17 86 5223 2146 2457 1714285 277 4461 3348 1507 1863 1959 2287 209 168 17 55 21 51 1274 655 72 62537 37272 48041 28313 29663 11962 16479 19509 38912 31419 3245 38586 35506 38739 57207 55832 13782 89 118328 149916 161062 117743 261921 1039904 42599 64609 93914 86568 60819 60868 57675 44783 45839 48172 Soil EWY-0 FDN BDY FRO BAC FRO IFT FRO LFT IFT FRO 22 23 28 24 25 29 26 27 632 13578 5696 16685 10821 17574 4412 16151 228306 2617844 2153998 2195418 22731 44 25525 21 1090828 1316162 25195 401 46 27996 35624 3093 369 12 12092 16131 812595 12471 77 809303 1241096 12923 18 12303 17 1203103 526873 252 1443 175 351 327 4 17 218 201 2939 951 74 2691 3134 2842 36 76 2699 1992 418877 6241 22 352544 4964.74 361552 5539 57 297687 306188 49469 84889 49383 305737 616 18 3354 59 47446 49714 1079 1306 678 1591 11 9 13 25 959 758 73025 66737 57476 42279 601 36 49783 32138 44276 13993 243 15 12208 25819 26327 26501 16482 11154 0 0 D a ’ a 0 z 0 C) a’ 0 0 C 0 a’ ------- Table A-id. CAP Pilot Study Multi-Element Data, House 43 a C a a S I a C z C -t C , ‘4 is C 0 C 0 a a Sample Idrilication Conc—ntrations (p9/9) Medium Component Location Sample ID Pb Al Ba Ca Cd Cr K Mg Ni Ti Zn Duat WCH WST ARD FLA BAl i EWY-l LVG KIT LVG DIN K IT LVG DIN LVG LVG DIN DIN DIN KIT KIT LVG DIN EWY EWY 05 38 04 16 36 09 19’ 01 03 11 12 13 31 32 08 18 20 21 96283 143363 96439 37835 39618 1137.67 611 38 14728 2048 23442 25576 14905 30191 309.13 102.12 19548 26347 58933 1371603 3536838 516815 1051271 917231 915241 659581 782678 691686 863223 7486 ,79 1039615 1341074 6497.66 11463.49 134452 1425466 38386 36137 52056 51198 44322 24313 22036 28836 41968 39332 21042 87281 593.49 2087 30442 33058 211325 5639876 13100 4743145 20181 33 3378892 6353554 15095 4332359 3013819 2190083 1496863 17116 36 250368 2797508 2214325 18154.49 2328933 893 7226 1817 2059 2206 1103 471 126 1.73 812 459 823 879 6 615 526 691 2381 325 8274 2855 4434 16475 . 3378 3019 515 4202 4411 47 04 456 3991 3162 3531 262 534436 463556 458629 663451 355389 41003 701708 3173751 861411 62741 680485 7385 11 690821 920171 111228 919123 605799 1403996 4535.1 4450 401788 421003 672457 . 294076 80882 372116 345041 2911.18 314581 443063 385689 410081 453116 446419 17.3 1818 2525 1745 2256 287 . 2313 2614 4487 215 1501 204 6153 2559 2579 1887 1641 50813 2443 440.36 311 83 35268 40836 . 198 25124 23053 23722 26214 291 45 42212 19796 3439 48626 46697 253841 111925 134371 694971 115981 780599 16441 98924 286697 116095 13154 94868 98063 298949 124749 76315 206626 Soil EWY-0 FDN SD ? Ff10 SAC SAC Ff10 SAC Ff10 Ff10 SAC 22 23 26 24 25 29 26 27 62277 20461 30405 33658 18072 24477 28961 6075 13817 34 1939988 1512008 1854827 2157086 1935304 1251732 533662 37445 37351 28312 46003 33868 33715 203 8322 1206842 1305533 1296142 1000294 1583413 824321 125337 579139 6.58 283 245 539 38 429 453 094 2865 3209 2588 4181 3642 3463 2833 1375 381292 455404 387982 380351 414451 319713 478004 173611 493 6 506 18 49309 306692 6104 240935 49145 30056 11 76 11 66 1071 1264 1406 1202 1212 951 32631 74013 49612 60108 72299 51659 41348 31351 491 55 30034 21117 81166 56124 48190’ 22139 8810 analysis result was greater than upper calibration limit for zinc, reported value ia a lower bound on the true Zn concentration asauming an instrument aample concentration of 5 pg/mL. ICP analysis hampered by calcium interference, no multi-element data reported ------- Table A-le. CAP Pilot Study Multi-Element Data, House 51 Sample Identification Concentrations tug/a) Medium Component Location Sample ID Pb Al Ba Ca Cd Cr IC Mg Ni Ti Zn Dust WCH WST FIR EWV-l BAT 6D3 803 BAT 8D3 BD3 BD1 BAT BD3 803 BD3 BD1 BD1 BD3 EWY EWY 07 15 17 06 14 16 40 01 11 12 13 31 32 44 20 21 27335 42097 49256 636701 77393 67018 358094 244616 96616 46655 71155 178438 176035 64648 64015 40262 483191 1334632 124968 402183 794958 916425 695302 440799 633688 115958 505573 5689.56 60863 328844 8493.4 711383 119476 28846 29992 67853 278.13 31415 74631 9302 4324 8619 13508 143281 32504 2704 23409 7553 1226355 1353355 1562875 1535659 9231311 7734641 7752348 133542 2643023 1483808 1132687 91261.26 3928109 1769777 129846 1272934 132 611 521 199 473 608 7 878 75 172 53 719 644 4.37 698 116 2609 3355 3376 3112 22.88 3032 2611 2065 2581 559 1683 2667 2289 1406 2245 3776 90078 327529 340675 90472 216789 3113.23 278275 1864.38 208407 81457 192261 169294 20503 175782 231994 1629 1454626 438673 455774 929264 473466 482295 512268 858939 301353 101629 559211 368986 313713 200657 721804 743466 525 2198 1946 165.25 9039 1886 2441 3598 1533 34 1349 1275 1192 802 1371 1978 36181 48532 56974 25934 34525 40651 48646 14892 18787 4414 17511 22554 25957 1171 2935 21149 319873 7528 54891 411193 83542 86583 217436 338741 96637 30397 78238 143514 147076 65703 74326 275947 Soil EWV .0 FDN BDY FRO BAC FRO BAC SAC FRO BAC BAC 22 23 24 25 28 26 27 29 8992 50471 93765 53896 42607 34581 32934 30049 8711.72 912617 916965 920729 931742 776156 819419 738651 231.52 26885 25838 26178 25677 20656 17685 1781 410207 579736 544899 796009 752254 593411 655566 707242 451 374 413 381 316 386 255 24 2237 2313 1592 2252 2017 2457 1922 1689 2287.08 264947 16075 242953 23088 222418 259753 243224 18991 30233 38385 151691 29547 30399 14909 168919 69 77 751 71 69 1118 614 583 3423 32398 378 34325 34636 3064 30505 27129 43252 37643 53306 37739 33984 31377 23503 21725 • Analysis result was greater than upper calibration limit for zinc; reported value is a lower bound on the true Zn concentration assuming an instrument sample concentration of 5 pg/mI During initial sampling attempt, cartridge filled with sawdust prior to completion of sample collection Sample was excluded from lead analysis and multi-element analysis An additional sample (ID 44) was taken to compensate for the loss of this sample I - r i ‘ 5 C ‘5 0 5 , 0 0 z 0 (1 ‘5 0 0 C 0 ‘5 ------- Table A-if. CAP Pilot Study Multi-Element Data, House 80 Sample Identification Concentrations (pg/g) Medium Component Location Sample ID Pb Al Ba Ca Cd Ci K Mg Ni Ti Zn Dust WCH WST ARD FIR BRU EWY.I BD3 KIT KIT BAT BD3 PAN KIT KIT BAT BD3 KIT BAT BAT BD3 BD3 003 KIT KIT BAT BD3 EWY EWY 15 41 42 06 14 36 39 40 09 19 45 01 03 11 12 13 31 32 08 18 20 21 93817 4550 579419 6157385 68012 53494 78807 46576 169936 96514 38948 1211.33 64918 17977 175.4 24278 1817 22333 344 3 6632 34228 2216 1161247 813736 113925 60989 611906 519784 383469 625781 58125 52732 3608.13 6872.02 8731 69 371825 480607 643044 4950.09 550859 7776.B8 209904 1176211 744436 84607 2246622 1088835 3031504 137666 6579447 2940219 655833 163709 36633 46969 100552 571.9 18597 17637 24019 322.95 35011 26282 101.32 303.49 25664 510127 6835811 2945978 2125135 3819057 1052487 2927588 4586667 4969503 3223993 13403.01 50977 32751 16 1394134 179657 9710.26 1820009 15063.71 41062 18 7622 978 25044.11 9819924 1758 2307 3037 3083 1715 785 2329 201 665 779 552 537 4.37 925 509 533 423 798 569 479 861 4 4971 9482 977 15136 6602 601 10421 20568 8399 7882 1692 3115 3238 4608 5942 4426 2535 5669 3607 3333 3327 2887 33384 95886 180519 153603 34805 2471 875 74495 315438 22064 348149 341719 384785 43785 351587 505449 384208 254197 3838.51 25092 113596 499187 67004 503225 405676 374558 508089 315553 2740865 242798 270906 376306 227704 181777 299118 2857 74 150536 194274 171868 188888 2293.53 295272 118064 370709 235301 1561 21.48 1473 42.43 9928 1591346 3535 13964 3764 1244 1007 1456 1851 5116 1954 1477 1055 21.54 15 21 42 51 2782 882 43949 71513 56778 1813 42613 62996 49368 46068 22536 20941 10344 22591 197.7 15545 17748 22446 23915 24299 272 11735 38857 30073 184876 4826.26 450938 3512127 1632.77 25875 7559.21 3467.03 596348 1171 51 123995 163863 117944 43573 50802 326.29 43631 51433 66444 13609 70344 46774 Soil EWY.O FDN BOY FRO BAC BAC IFT BAC BAC FRO BAC 22 23 28 24 25 29 26 27 37956 34975 411 94 941 59 45886 31683 30797 34253 1642786 1515385 1764231 1727246 88089 888523 12974.08 134267 281.68 28832 34022 41378 201 67 19759 24626 27856 6962 53 1053447 823478 6943.95 5155 78 74332 831715 7260 13 988 769 829 1398 606 756 93 6 19 31 33 319 31 81 3287 2299 2377 2402 2479 496823 470839 522336 444321 247422 256888 422044 4661 5 4892 50188 48699 77246 1512 5 149713 48946 1231 1151 1383 1382 743 805 951 48568 50074 52791 56427 322 17 28829 43714 385 15 41746 492 42 972 71 34504 37723 39431 • Analysis result was greater than upper calibration limit to, zinc, reported value is a lower bound on the true Zn Concentration assuming an instrument sample concentration of 5 pg/mL 0 0 z 0 * (1 ( 5 0 0 C 0 C D C D ‘C CD 0 CD ------- Table A-2. Geometric Mean Concentration by Sample Type and Unit Sample Type House Interior Abatement History Exterior Abatement History Renovation Samples Taken in Unit Ba Geometric Mean Concentrations_ija Ig) Pb Al Ca Cd Cr K Mg Ni Ti Zn WCH 33 43 51 80 U A E E U A A E Full 1 2 3 3 72383 11749 827 6 29136 133459 22025 3 9305.9 10248r 70578 3755 4693 59152 348661 27181 3 29601 8 461391 2966 2540 773 2309 3905 2782 30 92 7722 25634 49774 2158 1 17945 4237.1 7979 5 6625 4 42444 1786 1802 28 21 3669 655.7 352S 464.2 5630 137829 2089 1 1097.5 34266 WST 17 19 33 43 51 80 R U U R E E E U U fl R E Partial Full 6 3 4 3 4 5 368.3 1392 425.4 525 1 18544 38283 95057 51200 6836 3 7928 2 67183 34165 8176 1633 721 8 4907 4586 55561 332013 1007821 643059 31861 3 960192 409179 14020 1380 1522 4354 796 1810 3812 49.10 100.43 47 14 2740 105.18 74100 17084 32600 47642 20303 12544 71919 5090.4 4478 2 4222 3 5742.0 31059 43.74 4715 26.21 21.50 5121 5058 414.4 2983 422.0 3645 3648 4063 27815 7652 13543 2212.6 15947 52235 ARD 17 19 33 43 80 A U U A E E U U A E Pertial 2 1 2 1 3 510.6 6244 874.6 11377 861.2 88138 89480 5340.9 91524 48000 1799 585 1 2155 2431 6655 166151 696102 53114.2 635355 27795 2 20109 2372 3602 1103 659 5114 145 95 4641 16475 48 20 66955 3097 1 5553.4 41003 2971 9 37591 5103 5 27194 67246 24974 2110 312 90 3515 2870 16 77 2697 351 4 1884 4084 1696 45375 14659 16503.7 78060 20538 FIR 17 19 33 43 51 80 A U U A E E E U U R A 8 Partial Full 7 5 7 7 6 7 1655 173 1 1307 2209 12271 3048 55489 48306 99214 8504 5 50240 5668 4 6426 2174 2672 3800 1378 3388 146863 274705 256223 22451 7 542046 19605 1 917 787 3589 688 643 571 2883 65 56 20343 41 41 2063 4040 109740 23984 38547 88280 18900 37896 27265 3911 9 33415 3844 8 38705 21099 3995 76 26 2042 2729 1444 1903 1511 1459 2905 2642 1796 2066 5687 573 1 6476 1310 1 12352 6097 BRU 17 19 33 43 80 A U U R E E U U A E Partial 1 2 1 2 2 669 4833 1169 1413 151 1 51393 44446 119543 86305 4040 3 4338 3637 1625 2521 1632 190329 589430 182299 248889 176923 997 1041 2544 607 522 43.85 12327 6906 3878 34 67 80970 13954 67230 84568 16883 32100 33426 35583 39770 1867 1 7684 20842 1755 2569 2543 849 1663 3874 2609 178 7 5723 8194 4478 19312 3007 EWY-l 17 19 33 43 51 80 R U U R E 8 8 U U R A E Partial Full 2 2 2 2 2 2 2699 1926 1064 3940 16054 2754 102325 76408 19721 0 138440 77731 93574 6360 1250 2594 8358 1330 2791 142400 1149923 182262 205622 1285634 155217 1499 788 1971 603 900 587 3556 4040 221 98 3042 2912 3099 82685 33268 58122 77016 19440 18289 26593 64235 4477 1 44976 73255 29534 2759 3819 1655 1763 1646 1566 3076 2643 5652 4765 2491 3418 5138 5666 4699 1255.7 14321 573.6 —3 0 5 1 0 z 0 C, 51 0 0 C 0 p. C D ------- Table A-2. (Continued) Sample Type House Interior Abatement History Exterior Abatement History Renovation Samples Taken in Unit Geometric Mean Concentrations (4 Pb Al Ba Ca Cd Cr K lg) Mg Ni Ti Zn EWY-0 17 19 33 43 51 80 ft U U R E E E U U ft ft E Partial Full 2 3 3 3 2 3 1601 733 788 3384 673 7 3796 199947 155108 234370 16152.0 89165 16376.5 2935 1901 3048 3411 2495 3023 134889 135278 93606 126871 48766 84530 25.75 246 399 357 4 11 857 10069 2438 9097 2876 22.75 3168 49502 40834 45171 40690 2461 6 49622 575.9 5636 5919 4976 757 7 4926 5990 1183 985 1139 729 12.51 5323 4345 6543 4934 3330 5045 3002 2327 1607 342.3 403.5 4294 FDN 17 19 33 43 51 80 R U U H E E E U U ft ft E Partial Full 3 2 3 3 3 3 684 1083 1469 2460 5994 5164 189396 103680 233545 19783.7 9231 2 110573 207.4 1622 3439 3745 2590 2545 117340 12527.0 125429 109297 68844 64322 264 3 13 363 445 368 862 3932 2343 31 99 37 50 19 34 2619 47402 30960 46328 4092 1 2081 4 30453 17187 3902 1848 8 1652.2 566.2 12049 1463 12.96 1359 12.88 7 17 938 3988 331 9 502 1 6304 355 5 3742 3066 257 1 2686 605 7 4089 502.1 8DY 17 19 33 43 51 80 ft U U H E E 6 U U ft ft E Partial Full 3 3 2 2 3 2 592 57.3 860 132.6 3247 3248 238274 90156 11982 1 8192.7 17738 131984 2025 1156 1397 1300 1867 2619 112960 102708 7961 7 85198 65040 77707 254 205 209 206 287 759 4219 1817 23 19 1974 1998 2440 60637 32807 3019 1 28807 24131 44355 7972 9936 4857 3843 9148 4913 1632 725 853 1077 737 1025 5870 2788 3772 3853 2938 3775 1304 1310 1356 1401 2521 3952 U unabated unit. ft = removal unit, and E = encapsulationienclosure unit C D CD D Si 0 0 z 0 CD 0 0 CD cE ------- Revtew Draft - - Do Not Cite or Quote APPENDIX B OUTLIER ANALYSIS FOR THE CAPS PILOT MULTI-ELEMENT DATA ------- Review Draft -- Do Not Cite or Quote APPENDIX B OUTLIER ANALYSIS FOR THE CAPS PILOT MULTI-ELEMENT DATA B-]. INTRODUCTION This appendix documents the statistical outlier analysis performed on the CAPS Pilot multi-element data. The statistical approach employed, the outliers identified, and the findings of MRI’s review of the outlier data are discussed. Two outlier tests were applied to the multi-element data. The first was a univariate outlier test, which evaluates one element at a time. This is the same test that was previously applied to the lead data. The test was applied to the natural logarithms of the concentrations for lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc. The second test was a multivariate outlier test, which evaluates measurements for all eleven elements simultaneously. The multivariate test detects measurements which for a single element may not be an outlier, but when viewed in combination with the other elements is inconsistent with the majority of the data. Before performing the outlier tests, groupings of the data were defined. B-2 DATA GROUPING The following homogeneous groups of data were identified for each indicated sample type: • Vacuum Cassette Samples (7 groups) : air duct, upholstery (including bed coverings and throw rugs), interior entryway, floor (excluding entryway), window stool, window channel, and floor (including entryway); • Soil Samples (4 groups): boundary, foundation, exterior entryway, and all exterior samples combined. B-]. ------- Review Draft -. Do Not Cite or Quote Initially, data for all six units in the Pilot Study were combined before performing the univariate and multivariate outlier tests on these groups. When there were sufficient data, subsequent univariate outlier tests were also performed by segregating the data in each group by abatement method and by housing unit. Segregating by abatement method and unit were not done for the multivariate test due to the need for larger sample sizes with the increase in dimensionality. B-3 METHODS The details of the univariate and multivariate outlier tests are given in the following sections. B-3-l Univariate Outlier Test Formal statistical outlier tests were performed on the natural logarithms of the concentrations for lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium and zinc. Data were placed into groups of comparable values, and a maximum absolute studentized residual procedure was used to identify potential outliers. The SAS procedure GLM (SAS PC, ver. 6.08) was used to compute the studentized residual for each data value in a group by fitting a “constant” model (i.e., mean value plus error term) to the log-transformed data in each group. The absolute values of the studentized residuals were then compared to the upper .05/n quantile of a student-t distribution with n-2 degrees of freedom, where n is the number of data values in the group. If the maximum absolute studentized residual was greater than or equal to the .05/n quantile, the corresponding data value was flagged as a potential outlier. When a potential outlier was identified, that value was excluded from the group, and the outlier test was performed again. This procedure was repeated until no more outliers were detected. B-2 ------- Review Draft -- Do Not Cite or Quote B-3-2 Multivariate Outlier Test The multivariate outlier test is based on the Hotelling T- squared statistic, with one major difference (the Hotelling T- squared statistic is discussed in most multivariate statistics texts, such as Multivariate Statistical Methods. Second Edition , by Donald F. Morrison, copyright 1967, 1976 by McGraw-Hill, Inc., page 131) . The difference in the statistic used here is that, in computing the statistic for the i tt observation, that observation is excluded from the computation of the mean vector and the variance-covariance matrix. This yields estimates of location and covariance which are unaffected by the observation in question, and leads to a more robust outlier test. This is a multivariate extension of the univariate studentized residual used for the univariate outlier test. Under assumptions of normality, the resulting statistic has an F distribution, with numerator degrees of freedom equal to p (the number of elements) and denominator degrees of freedom equal to a function of p and the sample size, N. In this case, p was equal to eleven (the eleven elements are: lead, aluminum, barium, cadmium, calcium, chromium, magnesium, nickel, potassium, titanium, and zinc) The observation corresponding to the maximum value of the statistic in a data group was declared a potential outlier if the statistic exceeded the (1- .10/N) quantile of the F distribution with appropriate degrees of freedom. When a potential outlier was identified, that sample was excluded from the group, and the outlier test was performed again. This procedure was repeated until no more outliers were detected. B-4 RESULTS OF OUTLIER ANALYSIS The potential outliers identified by these two tests were screened by a statistician to eliminate those which were merely numerical anomalies due to very small sample sizes. The B-3 ------- Review Draft -. Do Not Cite or Quote remaining outliers identified by the univariate test are listed in Table B-i, and those identified by the multivariate test are listed in Table B-2. These lists of the remaining outliers were sent back to the laboratory for verification. However, the laboratory reported a few errors for several samples. The corrected values appear in Tables A-la through A-if while the original reported values can be found in the footnotes to these tables. B-4 ------- Review Draft -- Do Not Cite or Quote Table B-i. Univariate Outliers Detected by Univariate Methods Sample Processing Batch House ID! Sample ID Concentration IM Igl Al Ba Cd Cr Ni Ti Zn CLS 33/20 94 18 CRS 33/21 523 19 SSS 33/23 14.43 951.74 CSS 33/31 51597 CSS 33/32 676 48 SSS 43/22 6 58 SSS 43/26 _________ 4.53 SSS 43/27 094 1375 CSS 43/11 2866 r CSS 43/32 422 12 CKC 43/36 220 60 CKC 17/01 16.00 5500 50200 CLS 17/03 104.36 SSS 17/23 241 07 26894 238 ll CLS 19/04 231 35 CLS 19/08 18660 CLS 19113 152083 SSS 19125 485 SSS 19126 038 CLS 17119 61527 SKI 43(24 5 39 SSS 19(28 753 13 CLS 19/36 165.58 CRS 80/06 609.89 30315 04 181 30 35121 27 SSS 80(24 1398 564.27 972.71 SSS 80126 9 30 SSS 80(27 6 19 CLS 80109 5963.48 CLS 80(45 16.92 CSS 80(39 29402.19k CSS 80141 22466 2? CRS 51(12 1.72 5.59 4414 CLS 51(20 22.45 SSS 51/24 53306 SSS 51(26 386 CRS 33(19 99.07 CAS 43/16 306 14 These values were sent to MRI in a letter dated February 1 7. 1992. These values were confirmed by MRI via a fax received by Bettelle on July 24. 1995 All other values were sent to MRI in a letter dated January 14. 1992. B-5 ------- Table B-2. Outliers Detected by Multivariate Methods. Sample Processing Belch House Sample ID Concentration (jigig) Pb Al Ba Cd C Cr Mg Ni K Ti Zn CLS 17 03 253 9V 6949 83 1841.07 13 39 23113 58 29 35 3950 11 16 27 17158 68 104 36 1 338.25 CKC 17 01 50 1694 742 3 r 14246 16 19 2724 13 14419 55.07’ 502 CRS 80 06 6157385 60989 3031504 3083 2125135 16136 508089 4243 153603 1813 35121.27 SSS 51 26 345 8V 7761 56’ 206 56 3 86 5934.11. 24 57’ 303 99’ 11 18 2224 18 306.4 313 77’ SSS 17 23 36388 1958558 439.75 241 07 1416018 268.94 61415 23811 45706 582.48 49930 SSS 33 23 135 7 2617844 401 46 1443 12471 77 961 74 84889 1306 6241 22 66737 243 15 ‘These values were confirmed by MRI in a fax received by Battelle on July 28, 1995. All other values were confirmed by M I II in a fax received by Battelle on July 24. 1995 Performing the multivariate outlier test on only the elements lead, cadmium, chromium, titanium and zinc also identified the following samples as outliers (identified by House/Sample IDI 17/22. 19/23, 19/26. 33/21 and 51121 t j CD C CD 0 CD -I 0 0 z 0 c - I CD 0 -I 0 C 0 CD ------- |