Table of Contents

Component Description

Volatile Organic Compounds (Human Blood):

Exposure to volatile organic compounds (VOCs) is ubiquitous. Chronic exposure to extremely high levels of some VOCs can lead to cancer and neurocognitive dysfunction (1,2).

Nearly 200 air toxics have been associated with adverse health effects in occupational studies or laboratory studies, but have not been monitored in general population groups. Information on levels of exposure to these compounds as measured by their levels in blood is essential to determine the need for regulatory mechanisms to reduce the levels of hazardous air pollutants to which the general population is exposed.

Volatile Organic Compounds (Home Tap Water):

In addition to assessing levels of VOCs in blood, VOC levels will be measured in home tap water specimens provided by NHANES participants. Specifically, trihalomethanes (THMs) and the fuel additive methyl tertiary-butyl ether (MTBE) are measured in thesesamples.

Eligible Sample

In 1999, the eligible sample was a one-fourth subsample of persons 20–59 years; in 2000, it was a one-third subsample of persons 20–59 years. There were no component-specific exclusions.

Description of Laboratory Methodology

Measurements of Trihalomethanes (THMs) and MTBE in Tap
Water:

The prevalence of water disinfection by-products in drinking water
supplies has raised concerns about possible health effects from chronic
exposure to these compounds. The objective is to support studies
exploring the relationship between exposure to THMs and health
effects.

This automated analytical method uses headspace solid-phase microextraction (SPME) coupled with capillary gas chromatography and mass spectrometry (3). This method quantitates trace levels of THMs (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) and MTBE in tap water. Detection limits of less than 100 pg/mL for all analytes and linear ranges of three orders of magnitude are adequate for measuring the THMs in tap water samples tested from across the United States. THMs are stable for extended periods in tap water samples after quenching of residual chlorine and buffering to pH 6.5, thus enabling larger epidemiologic field studies with simplified sample collection protocols.

Measurements of THMs and MTBE in Whole Blood

The prevalence of water disinfection by-products (e.g. THMs) in tap water has raised concerns about possible health effects from chronic exposure to these compounds. Exposure to the fuel oxygenate MTBE has also raised concerns. People can be exposed to THMs and MTBE through a variety of sources, including use of household tap water that contains these chemicals. The objective of this study is to support studies exploring the relationship between health effects and exposure to THMs and MTBE. THMs and MTBE were quantified in human blood using capillary gas chromatography (GC) and high-resolution mass spectrometry (MS) with selected ion mass detection and isotope-dilution techniques (4). This method quantified trace levels of THMs (chloroform, bromodichloromethane, dibromochloromethane, and bromoform) and MTBE in human blood. Analyte responses were adequate for measuring background levels after extraction of these volatile organic compounds with either purge-and-trap extraction or headspace SPME. Detection limits ranged from 0.3–2.4 pg/mL, with linear ranges of three orders of magnitude. This method provided adequate sensitivity for measuring the THMs and MTBE in most blood samples tested from diverse U.S. reference population.

Measurements of other VOCs in Whole Blood

An additional 11 VOCs were measured in human blood using SPME in conjunction with gas chromatography and bench top quadrupole mass spectrometer (5). A combination of SPME and multiple single-ion monitoring minimizes the interferences and chemical noise associated with whole-blood samples. Detection limits are below 50 ppt (pg/mL) for a majority of the VOCs tested.

Data Processing and Editing

Automated data collection procedures for the survey were introduced in NHANES 1999–2000. In the MECs and analytical laboratories, data for the laboratory component are recorded directly onto a computerized data collection form. The system is centrally integrated, and it allows for ongoing monitoring of much of the data. Although the complete blood count and pregnancy analyses are performed in the MEC laboratory, most analyses are conducted elsewhere by approximately 21 laboratories across the United States. 

Guidelines have been developed that provide standards for naming variables, filling missing values, and handling missing records. NCHS staff, assisted by contract staff, has developed data-editing specifications that check data sets for valid codes, ranges, and skip- pattern consistencies and examine the consistency of values between interrelated variables. Comments have been reviewed and recoded. NCHS staff verifies extremely high and low values whenever possible, and numerous consistency checks are performed. Nonetheless, users should examine the range and frequency of values before analyzing data.  

Data Editing

The data editing specifications are as follows:

 

Laboratory Quality Assurance and Monitoring

Mobile Examination Centers (MECs)

Laboratory team performance is monitored using several techniques.

NCHS and contract consultants use a structured quality assurance evaluation during unscheduled visits to evaluate both the quality of the laboratory work and the quality-control procedures. Each laboratory staff person is observed for equipment operation, specimen collection and preparation; testing procedures and constructive feedback are given to each staff. Formal retraining sessions are conducted annually to ensure that required skill levels were maintained.

The NHANES QA/QC protocols meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the contract laboratories. In the MEC, these methods include performing second examinations on previously examined participants and blind split samples collected on "dry run" sessions. In addition, contract laboratories randomly perform repeat testing on 2.0% of all specimens.

NCHS developed and distributed a quality control protocol for all the contract laboratories which outlined the Westgaard rules used when running NHANES specimens. Progress reports containing any problems encountered during shipping or receipt of specimens, summary statistics for each control pool, QC graphs, instrument calibration, reagents, and any special considerations are submitted to NCHS and Westat quarterly. The reports are reviewed for trends or shifts in the data. The laboratories are required to explain any identified areas of concern. NCHS/Westat is currently reviewing these reports.

Analytic Notes

Measures of volatile organic compounds in blood and water were assessed in a subsample of participants aged 20–59. Use the special weights included in this data file when analyzing data. Please refer to the Analytic Guidelines for further details on the use of sample weights and other analytic issues.

The analysis of NHANES 1999-2000 laboratory data must be conducted with the key survey design and basic demographic variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively), which are included in the demographic data file for each data release. The NHANES 1999-2000 Household Questionnaire and Demographic Data Files contain demographic data, health indicators, and other related information collected during household interviews. The phlebotomy file includes auxiliary information such as the conditions precluding venipuncture. The demographic, household questionnaire and phlebotomy files may be linked to the laboratory data file using the unique survey participant identifier SEQN.

Detection limits

The detection limit was variable for many of the analytes in the data set. In addition two variables are provided for each of these analytes. The variable named LBD___LC indicates whether the result was below the limit of detection. There are three values: "0", "1", and "2". "0" means that the result was at or above the limit of detection. "1" indicates that the result was below the limit of detection. "2" means the result was above the limit of detection.

The other variable named LBX___ provides the analytic result for that analyte. In cases, where the result was below the limit of detection, the value for that variable is the detection limit divided by the square root of two.

References

Codebook and Frequencies

SEQN - Respondent sequence number

Variable Name:
SEQN
SAS Label:
Respondent sequence number
English Text:
Respondent sequence number.
Target:
Both males and females 20 YEARS - 59 YEARS

WTSVOC2Y - VOC subsample 2 yr MEC Weight

Variable Name:
WTSVOC2Y
SAS Label:
VOC subsample 2 yr MEC Weight
English Text:
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6703.435144 to 992877.35227 Range of Values 669 669
0 Non-Respondent 182 851
. Missing 0 851

WTSVOC4Y - VOC subsample 4 yr MEC Weight

Variable Name:
WTSVOC4Y
SAS Label:
VOC subsample 4 yr MEC Weight
English Text:
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2836.3452371 to 306407.42974 Range of Values 669 669
0 Non-Respondent 182 851
. Missing 0 851

LBXWBF - Water Bromoform (ng/ml)

Variable Name:
LBXWBF
SAS Label:
Water Bromoform (ng/ml)
English Text:
Bromoform Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0327 to 48.3 Range of Values 617 617
. Missing 234 851

LBXWCF - Water Chloroform (ng/ml)

Variable Name:
LBXWCF
SAS Label:
Water Chloroform (ng/ml)
English Text:
Chloroform Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1506 to 233 Range of Values 630 630
. Missing 221 851

LBXWBM - Water Bromodichloromethane (ng/ml)

Variable Name:
LBXWBM
SAS Label:
Water Bromodichloromethane (ng/ml)
English Text:
Bromodichloromethane Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0785 to 39.3 Range of Values 622 622
. Missing 229 851

LBXWCM - Water Dibromochloromethane (ng/ml)

Variable Name:
LBXWCM
SAS Label:
Water Dibromochloromethane (ng/ml)
English Text:
Dibromochloromethane Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0785 to 31.7 Range of Values 617 617
. Missing 234 851

LBXWME - Water MTBE (ng/ml)

Variable Name:
LBXWME
SAS Label:
Water MTBE (ng/ml)
English Text:
Methyl tert. butyl ether (MTBE) Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0707 to 25.4 Range of Values 620 620
. Missing 231 851

LBXV4C - Blood Tetrachloroethene (ng/ml)

Variable Name:
LBXV4C
SAS Label:
Blood Tetrachloroethene (ng/ml)
English Text:
Tetrachloroethene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0144 to 9.7 Range of Values 286 286
. Missing 565 851

LBXVBF - Blood Bromoform (pg/ml)

Variable Name:
LBXVBF
SAS Label:
Blood Bromoform (pg/ml)
English Text:
Bromoform Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.3543 to 20.3 Range of Values 330 330
. Missing 521 851

LBXVBM - Blood Bromodichloromethane (pg/ml)

Variable Name:
LBXVBM
SAS Label:
Blood Bromodichloromethane (pg/ml)
English Text:
Bromodichloromethane Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1563 to 47.4 Range of Values 354 354
. Missing 497 851

LBXVBZ - Blood Benzene (ng/ml)

Variable Name:
LBXVBZ
SAS Label:
Blood Benzene (ng/ml)
English Text:
Benzene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0323 to 1.69 Range of Values 300 300
. Missing 551 851

LBXVCF - Blood Chloroform (pg/ml)

Variable Name:
LBXVCF
SAS Label:
Blood Chloroform (pg/ml)
English Text:
Chloroform Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6.42 to 1570 Range of Values 255 255
. Missing 596 851

LBXVCM - Blood Dibromochloromethane (pg/ml)

Variable Name:
LBXVCM
SAS Label:
Blood Dibromochloromethane (pg/ml)
English Text:
Dibromochloromethane Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.152 to 57 Range of Values 350 350
. Missing 501 851

LBXVCT - Blood Carbon Tetrachloride (ng/ml)

Variable Name:
LBXVCT
SAS Label:
Blood Carbon Tetrachloride (ng/ml)
English Text:
Carbon Tetrachloride Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 0.116 Range of Values 287 287
. Missing 564 851

LBXVDB - Blood 1,4-Dichlorobenzene (ng/ml)

Variable Name:
LBXVDB
SAS Label:
Blood 1,4-Dichlorobenzene (ng/ml)
English Text:
1,4-Dichlorobenzene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.026 to 249 Range of Values 304 304
. Missing 547 851

LBXVEB - Blood Ethylbenzene (ng/ml)

Variable Name:
LBXVEB
SAS Label:
Blood Ethylbenzene (ng/ml)
English Text:
Ethylbenzene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.01 to 5.16 Range of Values 262 262
. Missing 589 851

LBXVME - Blood MTBE (pg/ml)

Variable Name:
LBXVME
SAS Label:
Blood MTBE (pg/ml)
English Text:
Methyl t-Butyl Ether (MTBE) Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.784 to 6270 Range of Values 284 284
. Missing 567 851

LBXVOX - Blood o-Xylene (ng/ml)

Variable Name:
LBXVOX
SAS Label:
Blood o-Xylene (ng/ml)
English Text:
o-Xylene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.021 to 6.42 Range of Values 309 309
. Missing 542 851

LBXVST - Blood Styrene (ng/ml)

Variable Name:
LBXVST
SAS Label:
Blood Styrene (ng/ml)
English Text:
Styrene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0066 to 9.45 Range of Values 284 284
. Missing 567 851

LBXVTC - Blood Trichloroethene (ng/ml)

Variable Name:
LBXVTC
SAS Label:
Blood Trichloroethene (ng/ml)
English Text:
Trichloroethene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0066 to 0.923 Range of Values 303 303
. Missing 548 851

LBXV3A - Blood 1,1,1-Trichloroethane (ng/ml)

Variable Name:
LBXV3A
SAS Label:
Blood 1,1,1-Trichloroethane (ng/ml)
English Text:
1,1,1-Trichloroethane Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0161 to 4.26 Range of Values 286 286
. Missing 565 851

LBXVTO - Blood Toluene (ng/ml)

Variable Name:
LBXVTO
SAS Label:
Blood Toluene (ng/ml)
English Text:
Toluene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0231 to 10.2 Range of Values 304 304
. Missing 547 851

LBXVXY - Blood m-/p-Xylene (ng/ml)

Variable Name:
LBXVXY
SAS Label:
Blood m-/p-Xylene (ng/ml)
English Text:
m-/p-Xylene Result
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0358 to 14.3 Range of Values 296 296
. Missing 555 851

LBDWBFLC - Water Bromoform Comment Code

Variable Name:
LBDWBFLC
SAS Label:
Water Bromoform Comment Code
English Text:
Bromoform Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 428 428
1 Below Detectable Limit 188 616
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 617
. Missing 234 851

LBDWCFLC - Water Chloroform Comment Code

Variable Name:
LBDWCFLC
SAS Label:
Water Chloroform Comment Code
English Text:
Chloroform Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 526 526
1 Below Detectable Limit 103 629
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 630
. Missing 221 851

LBDWBMLC - Water Bromodichloromethane Comment Code

Variable Name:
LBDWBMLC
SAS Label:
Water Bromodichloromethane Comment Code
English Text:
Bromodichloromethane Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 521 521
1 Below Detectable Limit 101 622
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 622
. Missing 229 851

LBDWCMLC - Water Dibromochloromethane Comment Code

Variable Name:
LBDWCMLC
SAS Label:
Water Dibromochloromethane Comment Code
English Text:
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 531 531
1 Below Detectable Limit 86 617
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 617
. Missing 234 851

LBDWMELC - Water MTBE Comment Code

Variable Name:
LBDWMELC
SAS Label:
Water MTBE Comment Code
English Text:
Methyl tert. butyl ether (MTBE) Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 180 180
1 Below Detectable Limit 440 620
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 620
. Missing 231 851

LBDV4CLC - Blood Tetrachloroethene Comment Code

Variable Name:
LBDV4CLC
SAS Label:
Blood Tetrachloroethene Comment Code
English Text:
Tetrachloroethene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 218 218
1 Below Detectable Limit 65 283
2 Detectable Result and Exceeds the Calibrated Range of Assay 3 286
. Missing 565 851

LBDVBFLC - Blood Bromoform Comment Code

Variable Name:
LBDVBFLC
SAS Label:
Blood Bromoform Comment Code
English Text:
Bromoform Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 251 251
1 Below Detectable Limit 79 330
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 330
. Missing 521 851

LBDVBMLC - Blood Bromodichloromethane Comment Code

Variable Name:
LBDVBMLC
SAS Label:
Blood Bromodichloromethane Comment Code
English Text:
Bromodichloromethane Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 336 336
1 Below Detectable Limit 18 354
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 354
. Missing 497 851

LBDVBZLC - Blood Benzene Comment Code

Variable Name:
LBDVBZLC
SAS Label:
Blood Benzene Comment Code
English Text:
Benzene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 300 300
1 Below Detectable Limit 0 300
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 300
. Missing 551 851

LBDVCFLC - Blood Chloroform Comment Code

Variable Name:
LBDVCFLC
SAS Label:
Blood Chloroform Comment Code
English Text:
Chloroform Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 253 253
1 Below Detectable Limit 0 253
2 Detectable Result and Exceeds the Calibrated Range of Assay 2 255
. Missing 596 851

LBDVCMLC - Blood Dibromochloromethane Comment Code

Variable Name:
LBDVCMLC
SAS Label:
Blood Dibromochloromethane Comment Code
English Text:
Dibromochloromethane Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 303 303
1 Below Detectable Limit 47 350
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 350
. Missing 501 851

LBDVCTLC - Blood Carbon Tetrachloride Comment Code

Variable Name:
LBDVCTLC
SAS Label:
Blood Carbon Tetrachloride Comment Code
English Text:
Carbon Tetrachloride Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 87 87
1 Below Detectable Limit 200 287
2 Detectable Result and Exceeds the Calibrated Range of Assay 0 287
. Missing 564 851

LBDVDBLC - Blood 1,4-Dichlorobenzene Comment Code

Variable Name:
LBDVDBLC
SAS Label:
Blood 1,4-Dichlorobenzene Comment Code
English Text:
1,4-Dichlorobenzene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 253 253
1 Below Detectable Limit 34 287
2 Detectable Result and Exceeds the Calibrated Range of Assay 17 304
. Missing 547 851

LBDVEBLC - Blood Ethylbenzene Comment Code

Variable Name:
LBDVEBLC
SAS Label:
Blood Ethylbenzene Comment Code
English Text:
Ethylbenzene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 235 235
1 Below Detectable Lilmit 26 261
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 262
. Missing 589 851

LBDVMELC - Blood MTBE Comment Code

Variable Name:
LBDVMELC
SAS Label:
Blood MTBE Comment Code
English Text:
MTBE Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 247 247
1 Below Detectable Limit 4 251
2 Detectable Result and Exceeds the Calibrated Range of Assay 33 284
. Missing 567 851

LBDVOXLC - Blood o-Xylene Comment Code

Variable Name:
LBDVOXLC
SAS Label:
Blood o-Xylene Comment Code
English Text:
o-Xylene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 180 180
1 Below Detectable Limit 128 308
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 309
. Missing 542 851

LBDVSTLC - Blood Styrene Comment Code

Variable Name:
LBDVSTLC
SAS Label:
Blood Styrene Comment Code
English Text:
Styrene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 268 268
1 Below Detectable Limit 15 283
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 284
. Missing 567 851

LBDVTCLC - Blood Trichloroethene Comment Code

Variable Name:
LBDVTCLC
SAS Label:
Blood Trichloroethene Comment Code
English Text:
Trichloroethene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 34 34
1 Below Detectable Limit 268 302
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 303
. Missing 548 851

LBDV3ALC - Blood 1,1,1-Trichloroethane Comment Code

Variable Name:
LBDV3ALC
SAS Label:
Blood 1,1,1-Trichloroethane Comment Code
English Text:
1,1,1-Trichloroethane Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 11 11
1 Below Detectable Limit 274 285
2 Detectable Result and Exceeds the Calibrated Range of Assay 1 286
. Missing 565 851

LBDVTOLC - Blood Toluene Comment Code

Variable Name:
LBDVTOLC
SAS Label:
Blood Toluene Comment Code
English Text:
Toluene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 294 294
1 Below Detectable Limit 4 298
2 Detectable Result and Exceeds the Calibrated Range of Assay 6 304
. Missing 547 851

LBDVXYLC - Blood m-/p-Xylene Comment Code

Variable Name:
LBDVXYLC
SAS Label:
Blood m-/p-Xylene Comment Code
English Text:
m-/p-Xylene Comment
Target:
Both males and females 20 YEARS - 59 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 Detectable Result 284 284
1 Below Detectable Limit 10 294
2 Detectable Result and Exceeds the Calibrated Range of Assay 2 296
. Missing 555 851