Table of Contents

Component Description

Volatile Organic Compounds and Trihalomethanes/MTBE (Whole Blood)

Volatile organic compounds (VOCs) are a large group of chemicals that have been used as solvents, degreasers, and cleaning agents in industry and consumer products. Many of the VOCs were found to contaminate ground water and drinking water sources. Because of human health concerns, these VOCs have been banned or restricted from most uses.

The halogenated solvents are VOCs consisting of a hydrocarbon chain or one hydrocarbon substituted with one or more chlorine or bromine atoms. Most of these chemicals are used as degreasers and solvents in various products, such as paint. In the past, 1,1,1-trichloroethane was used as a dry cleaning agent, insect fumigant, and solvent in consumer products. Methylene chloride, tetrachloroethene, and trichloroethene are other VOCs that were widely used in the past.

Benzene, toluene, ethylbenzene, xylene, and styrene, collectively referred to as BTEXS, are components of tobacco smoke. Along with 2,5-dimethylfuran, these VOCs are usually detected in the blood of cigarette smokers at higher levels than in non-smokers. Chlorobenzene (monochlorobenzene) and the three dichlorobenzenes are halogenated aromatic hydrocarbons primarily used in industrial and chemical synthetic processes. Chlorobenzene has been used to produce DDT, phenol, and nitrobenzene. The dichlorobenzenes are also chemical intermediates in the synthesis of dyes, pesticides, and other industrial products. 1,4-Dichlorobenzene (para-dichlorobenzene) is used also as a moth repellent and as a deodorizer. Disinfection by-products (DBP), including bromodichloromethane, dibromochloromethane, bromoform, and chloroform are formed when chlorine interacts with natural organic materials found in water. Primary sources of DBPs are chlorinated drinking water and recreational water bodies, such as swimming pools.

The prevalence of disinfection by-products in drinking water supplies has raised concerns about possible adverse health effects from chronic exposure to these potentially carcinogenic compounds. Methyl-tert-butyl ether (MTBE) was used as an additive to replace lead in gasoline, but its use was banned after widespread ground water contamination was discovered.

Inhalation is the most common VOC route of exposure in the general population, including indoor sources such as paints, adhesives, cleaning solutions, and aerosolized insecticide sprays; industries producing these solvents; and contaminated waste disposal sites. Drinking water may contribute to exposure when underground drinking water supplies are contaminated. After they are absorbed in the body, VOCs are rapidly eliminated in exhaled breath, or may be rapidly metabolized and eliminated in the urine.


Eligible Sample

Participants aged 18 years and older, who met the regular one-half subsample selection criteria, were included in this special subsample. Additionally, to oversample adult smokers, those participants aged 18 years and older, not in the regular one-half subsample, who smoked at least 100 cigarettes in their entire lifetime (SMQ020=1) and now smoke cigarettes every day (SMQ040=1), were also included in this special subsample.


Description of Laboratory Methodology

An automated analytical method was developed using capillary gas chromatography (GC) and mass spectrometry (MS) with selected-ion monitoring (SIM) detection and isotope-dilution. This method quantifies levels of individual VOCs and Trihalomethanes (THMs) and methyl tert-butyl ether (MTBE) in whole blood to low-parts-per-trillion range. Because non-occupationally exposed individuals have blood VOC concentrations within this range, this method is applicable for determining these quantities and investigating cases of sustained or recent low-level exposure.

Refer to the Laboratory Method Files section for a detailed description of the laboratory methods used.

There were no changes to the lab method, lab equipment, or lab site for this component in the NHANES 2015-2016 cycle.


Laboratory Method Files

Volatile Organic Compounds (VOCs) & Trihalomethanes/MTBE Laboratory Procedure Manual (September 2018)

Laboratory Quality Assurance and Monitoring

Whole blood specimens were processed, stored, and shipped to Division of Laboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention, Atlanta, GA for analysis.

Detailed instructions on specimen collection and processing are discussed in the NHANES Laboratory Procedures Manual (LPM). Vials are stored under appropriate refrigerated (2-8°C) conditions until they are shipped to National Center for Environmental Health for testing.

The NHANES quality assurance and quality control (QA/QC) protocols meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES LPM.

Mobile Examination Centers (MECs)

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

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 blind split samples collected on “dry run” sessions. In addition, contract laboratories randomly perform repeat testing on 2% of all specimens.

NCHS developed and distributed a quality control protocol for all CDC and contract laboratories which outlined the use of Westgard rules (Westgard et al., 1981) 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 quarterly. The reports are reviewed for trends or shifts in the data. The laboratories are required to explain any identified areas of concern.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet Division of Laboratory Services’ quality control and quality assurance performance criteria for accuracy and precision, similar to the Westgard rules (Caudill et al., 2008).

Data Processing and Editing

The data were reviewed. Incomplete data or improbable values were sent to the performing laboratory for confirmation.


Analytic Notes

Refer to the 2015-2016 Laboratory Data Overview for general information on NHANES laboratory data.

Volatile Toxicant Questionnaire

 A volatile toxicant questionnaire (VTQ) was administered on the mobile examination center (MEC), by trained interviewers, using the Computer-Assisted Personal Interview (CAPI) system. The VTQ section includes data about the SP’s home, activities, amount of time spent in various locations, and exposure to different chemicals over the past 48 hours. This questionnaire data can be used in conjunction with the VOC laboratory dataset and found in the Volatile Toxicant Data File in the NHANES 2015-2016 Questionnaire Data section.

Subsample Weights

Whole blood VOCs were measured in a one-half subsample of participants 18 years and older. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should be used when analyzing these data.

Demographic and Other Related Variables

The analysis of NHANES laboratory data must be conducted using the appropriate survey design and demographic variables. The NHANES 2015-2016 Demographics File contains demographic data, health indicators, and other related information collected during household interviews as well as the sample design variables. The recommended procedure for variance estimation requires use of stratum and PSU variables (SDMVSTRA and SDMVPSU, respectively) in the demographic data file.

The Fasting Questionnaire file includes auxiliary information such as fasting status, the time of venipuncture, and the conditions precluding venipuncture.

This laboratory data file can be linked to the other NHANES data files using the unique survey participant identifier (i.e., SEQN).

Detection limits

The detection limits were constant for all of the analytes in the data set. Two variables are provided for each of these analytes. The variable name ending in “LC” (ex., LBD2DFLC) indicates whether the result was below the limit of detection: “0” means that the result was at or above the limit of detection, “1” indicates that the result was below the limit of detection. For analytes with analytic results below the lower limit of detection (ex., LBD2DFLC=1), an imputed fill value was placed in the analyte results field. This value is the lower limit of detection divided by square root of 2 (LLOD/sqrt [2]). The other variable prefixed LBX (ex., LBX2DF) provides the analytic result for that analyte. All data are rounded to three significant figures or three decimal places, whichever is less precise.

Lower Limit of Detection (LLOD, in ng/mL) for Whole Blood VOCs:

VARIABLE NAME

SAS LABEL

LLOD

LBX2DF

Blood 2,5-Dimethylfuran (ng/mL)

0.011

LBX4CE

Blood 1,1,1,2-Tetrachloroethane (ng/mL)

0.040

LBXV06

Blood Hexane (ng/mL)

0.122

LBXV07N

Blood Heptane (ng/mL)

0.100

LBXV08N

Blood Octane (ng/mL)

0.100

LBXV1D

Blood 1,2-Dichlorobenzene (ng/mL)

0.025

LBXV2A

Blood 1,2-Dichloroethane (ng/mL)

0.010

LBXV3B

Blood 1,3-Dichlorobenzene (ng/mL)

0.025

LBXV4C

Blood Tetrachloroethene (ng/mL)

0.048

LBXVBF

Blood Bromoform (ng/mL)

0.008

LBXVBM

Blood Bromodichloromethane (ng/mL)

0.006

LBXVBZ

Blood Benzene (ng/mL)

0.024

LBXVBZN

Blood Benzonitrile (ng/mL) 

0.150

LBXVC6

Blood Cyclohexane (ng/mL)

0.020

LBXVCB

Blood Chlorobenzene (ng/mL)

0.011

LBXVCF

Blood Chloroform (ng/mL)

0.008

LBXVCM

Blood Dibromochloromethane (ng/mL)

0.005

LBXVCT

Blood Carbon Tetrachloride (ng/mL)

0.005

LBXVDB

Blood 1,4-Dichlorobenzene (ng/mL)

0.040

LBXVDE

Blood 1,2-Dibromoethane (ng/ml)

0.015

LBXVDEE

Blood Diethyl Ether (ng/mL)

0.040

LBXVDX

Blood 1,4-Dioxane (ng/mL)

0.500

LBXVEA

Blood Ethyl Acetate (ng/mL)

0.158

LBXVEB

Blood Ethylbenzene (ng/mL)

0.024

LBXVEC

Blood Chloroethane (ng/mL)

0.045

LBXVFN

Blood Furan (ng/ml)

0.025

LBXVIBN

Blood Isobutyronitrile (ng/mL)

0.040

LBXVIPB

Blood Isopropylbenzene (ng/ml)

0.040

LBXVMC

Blood Methylene Chloride (ng/mL)

0.250

LBXVMCP

Blood Methylcyclopentane (ng/mL)

0.020

LBXVME

Blood MTBE (ng/mL)

0.010

LBXVNB

Blood Nitrobenzene (ng/mL)

0.320

LBXVOX

Blood o-Xylene (ng/mL)

0.024

LBXVTC

Blood Trichloroethene (ng/mL)

0.012

LBXVTE

Blood 1,1,1-Trichloroethane (ng/mL)

0.010

LBXVTFT

Blood ααα-Trifluorotoluene (ng/mL)

0.040

LBXVTHF

Blood Tetrahydrofuran (ng/mL)

0.125

LBXVTO

Blood Toluene (ng/mL)

0.025

LBXVTP

Blood 1,2,3-Trichloropropane (ng/ml)

0.040

LBXVVB

Blood Vinyl Bromide (ng/mL)

0.045

LBXVXY

Blood m-/p-Xylene (ng/mL)

0.034

Please refer to the NHANES Analytic Guidelines and the on-line NHANES Tutorial for further details on the use of sample weights and other analytic issues.

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 18 YEARS - 150 YEARS

WTSVS2YR - VOC Smoking Subsample Weight

Variable Name:
WTSVS2YR
SAS Label:
VOC Smoking Subsample Weight
English Text:
Two year smoking weights
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
5744.883139 to 533055.09127 Range of Values 3017 3017
0 No Lab Result 249 3266
. Missing 0 3266

LBX2DF - Blood 2,5-Dimethylfuran (ng/mL)

Variable Name:
LBX2DF
SAS Label:
Blood 2,5-Dimethylfuran (ng/mL)
English Text:
Blood 2,5-Dimethylfuran (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.008 to 1.45 Range of Values 3010 3010
. Missing 256 3266

LBD2DFLC - Blood 2,5-Dimethylfuran Comment Code

Variable Name:
LBD2DFLC
SAS Label:
Blood 2,5-Dimethylfuran Comment Code
English Text:
Blood 2,5-Dimethylfuran Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 874 874
1 Below lower detection limit 2136 3010
2 Detectable result and exceeds the calibrated range of assay 0 3010
. Missing 256 3266

LBX4CE - Blood 1,1,1,2-Tetrachloroethane (ng/mL)

Variable Name:
LBX4CE
SAS Label:
Blood 1,1,1,2-Tetrachloroethane (ng/mL)
English Text:
Blood 1,1,1,2-Tetrachloroethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 0.028 3009 3009
. Missing 257 3266

LBD4CELC - Blood 1,1,1,2-Tetrachloroethane Cmt Code

Variable Name:
LBD4CELC
SAS Label:
Blood 1,1,1,2-Tetrachloroethane Cmt Code
English Text:
Blood 1,1,1,2-Tetrachloroethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 3009 3009
2 Detectable result and exceeds the calibrated range of assay 0 3009
. Missing 257 3266

LBXV06 - Blood Hexane (ng/mL)

Variable Name:
LBXV06
SAS Label:
Blood Hexane (ng/mL)
English Text:
Blood Hexane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.086 to 20.9 Range of Values 2772 2772
. Missing 494 3266

LBDV06LC - Blood Hexane Comment Code

Variable Name:
LBDV06LC
SAS Label:
Blood Hexane Comment Code
English Text:
Blood Hexane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 19 19
1 Below lower detection limit 2753 2772
2 Detectable result and exceeds the calibrated range of assay 0 2772
. Missing 494 3266

LBXV07N - Blood Heptane (ng/mL)

Variable Name:
LBXV07N
SAS Label:
Blood Heptane (ng/mL)
English Text:
Blood Heptane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 3.54 Range of Values 2914 2914
. Missing 352 3266

LBDV07LC - Blood Heptane Comment Code

Variable Name:
LBDV07LC
SAS Label:
Blood Heptane Comment Code
English Text:
Blood Heptane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 33 33
1 Below lower detection limit 2881 2914
2 Detectable result and exceeds the calibrated range of assay 0 2914
. Missing 352 3266

LBXV08N - Blood Octane (ng/mL)

Variable Name:
LBXV08N
SAS Label:
Blood Octane (ng/mL)
English Text:
Blood Octane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.071 to 1.58 Range of Values 2928 2928
. Missing 338 3266

LBDV08LC - Blood Octane Comment Code

Variable Name:
LBDV08LC
SAS Label:
Blood Octane Comment Code
English Text:
Blood Octane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 10 10
1 Below lower detection limit 2918 2928
2 Detectable result and exceeds the calibrated range of assay 0 2928
. Missing 338 3266

LBXV1D - Blood 1,2-Dichlorobenzene (ng/mL)

Variable Name:
LBXV1D
SAS Label:
Blood 1,2-Dichlorobenzene (ng/mL)
English Text:
Blood 1,2-Dichlorobenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.018 to 0.092 Range of Values 2935 2935
. Missing 331 3266

LBDV1DLC - Blood 1,2-Dichlorobenzene Comment Code

Variable Name:
LBDV1DLC
SAS Label:
Blood 1,2-Dichlorobenzene Comment Code
English Text:
Blood 1,2-Dichlorobenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1 1
1 Below lower detection limit 2934 2935
2 Detectable result and exceeds the calibrated range of assay 0 2935
. Missing 331 3266

LBXV2A - Blood 1,2-Dichloroethane (ng/mL)

Variable Name:
LBXV2A
SAS Label:
Blood 1,2-Dichloroethane (ng/mL)
English Text:
Blood 1,2-Dichloroethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 0.109 Range of Values 2970 2970
. Missing 296 3266

LBDV2ALC - Blood 1,2-Dichloroethane Comment Code

Variable Name:
LBDV2ALC
SAS Label:
Blood 1,2-Dichloroethane Comment Code
English Text:
Blood 1,2-Dichloroethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 101 101
1 Below lower detection limit 2869 2970
2 Detectable result and exceeds the calibrated range of assay 0 2970
. Missing 296 3266

LBXV3B - Blood 1,3-Dichlorobenzene (ng/mL)

Variable Name:
LBXV3B
SAS Label:
Blood 1,3-Dichlorobenzene (ng/mL)
English Text:
Blood 1,3-Dichlorobenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.018 to 0.018 Range of Values 2970 2970
. Missing 296 3266

LBDV3BLC - Blood 1,3-Dichlorobenzene Comment Code

Variable Name:
LBDV3BLC
SAS Label:
Blood 1,3-Dichlorobenzene Comment Code
English Text:
Blood 1,3-Dichlorobenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2970 2970
2 Detectable result and exceeds the calibrated range of assay 0 2970
. Missing 296 3266

LBXV4C - Blood Tetrachloroethene (ng/mL)

Variable Name:
LBXV4C
SAS Label:
Blood Tetrachloroethene (ng/mL)
English Text:
Blood Tetrachloroethene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.034 to 16 Range of Values 3017 3017
. Missing 249 3266

LBDV4CLC - Blood Tetrachloroethene Comment Code

Variable Name:
LBDV4CLC
SAS Label:
Blood Tetrachloroethene Comment Code
English Text:
Blood Tetrachloroethene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 190 190
1 Below lower detection limit 2827 3017
2 Detectable result and exceeds the calibrated range of assay 0 3017
. Missing 249 3266

LBXVBF - Blood Bromoform (ng/mL)

Variable Name:
LBXVBF
SAS Label:
Blood Bromoform (ng/mL)
English Text:
Blood Bromoform (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.006 to 0.139 Range of Values 2969 2969
. Missing 297 3266

LBDVBFLC - Blood Bromoform Comment Code

Variable Name:
LBDVBFLC
SAS Label:
Blood Bromoform Comment Code
English Text:
Blood Bromoform Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 271 271
1 Below lower detection limit 2698 2969
2 Detectable result and exceeds the calibrated range of assay 0 2969
. Missing 297 3266

LBXVBM - Blood Bromodichloromethane (ng/mL)

Variable Name:
LBXVBM
SAS Label:
Blood Bromodichloromethane (ng/mL)
English Text:
Blood Bromodichloromethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.004 to 0.068 Range of Values 3003 3003
. Missing 263 3266

LBDVBMLC - Blood Bromodichloromethane Comment Code

Variable Name:
LBDVBMLC
SAS Label:
Blood Bromodichloromethane Comment Code
English Text:
Blood Bromodichloromethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 528 528
1 Below lower detection limit 2475 3003
2 Detectable result and exceeds the calibrated range of assay 0 3003
. Missing 263 3266

LBXVBZ - Blood Benzene (ng/mL)

Variable Name:
LBXVBZ
SAS Label:
Blood Benzene (ng/mL)
English Text:
Blood Benzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.017 to 2.75 Range of Values 2966 2966
. Missing 300 3266

LBDVBZLC - Blood Benzene Comment Code

Variable Name:
LBDVBZLC
SAS Label:
Blood Benzene Comment Code
English Text:
Blood Benzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1441 1441
1 Below lower detection limit 1525 2966
2 Detectable result and exceeds the calibrated range of assay 0 2966
. Missing 300 3266

LBXVBZN - Blood Benzonitrile (ng/mL)

Variable Name:
LBXVBZN
SAS Label:
Blood Benzonitrile (ng/mL)
English Text:
Blood Benzonitrile (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.106 to 1.92 Range of Values 2959 2959
. Missing 307 3266

LBDVZBLC - Blood Benzonitrile Comment Code

Variable Name:
LBDVZBLC
SAS Label:
Blood Benzonitrile Comment Code
English Text:
Blood Benzonitrile Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 271 271
1 Below lower detection limit 2688 2959
2 Detectable result and exceeds the calibrated range of assay 0 2959
. Missing 307 3266

LBXVC6 - Blood Cyclohexane (ng/mL)

Variable Name:
LBXVC6
SAS Label:
Blood Cyclohexane (ng/mL)
English Text:
Blood Cyclohexane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.014 to 12.7 Range of Values 2896 2896
. Missing 370 3266

LBDVC6LC - Blood Cyclohexane Comment Code

Variable Name:
LBDVC6LC
SAS Label:
Blood Cyclohexane Comment Code
English Text:
Blood Cyclohexane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 48 48
1 Below lower detection limit 2848 2896
2 Detectable result and exceeds the calibrated range of assay 0 2896
. Missing 370 3266

LBXVCB - Blood Chlorobenzene (ng/mL)

Variable Name:
LBXVCB
SAS Label:
Blood Chlorobenzene (ng/mL)
English Text:
Blood Chlorobenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.008 to 0.043 Range of Values 2996 2996
. Missing 270 3266

LBDVCBLC - Blood Chlorobenzene Comment Code

Variable Name:
LBDVCBLC
SAS Label:
Blood Chlorobenzene Comment Code
English Text:
Blood Chlorobenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 2 2
1 Below lower detection limit 2994 2996
2 Detectable result and exceeds the calibrated range of assay 0 2996
. Missing 270 3266

LBXVCF - Blood Chloroform (ng/mL)

Variable Name:
LBXVCF
SAS Label:
Blood Chloroform (ng/mL)
English Text:
Blood Chloroform (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.006 to 0.619 Range of Values 2905 2905
. Missing 361 3266

LBDVCFLC - Blood Chloroform Comment Code

Variable Name:
LBDVCFLC
SAS Label:
Blood Chloroform Comment Code
English Text:
Blood Chloroform Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1688 1688
1 Below lower detection limit 1217 2905
2 Detectable result and exceeds the calibrated range of assay 0 2905
. Missing 361 3266

LBXVCM - Blood Dibromochloromethane (ng/mL)

Variable Name:
LBXVCM
SAS Label:
Blood Dibromochloromethane (ng/mL)
English Text:
Blood Dibromochloromethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.004 to 0.071 Range of Values 3014 3014
. Missing 252 3266

LBDVCMLC - Blood Dibromochloromethane Comment Code

Variable Name:
LBDVCMLC
SAS Label:
Blood Dibromochloromethane Comment Code
English Text:
Blood Dibromochloromethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 441 441
1 Below lower detection limit 2573 3014
2 Detectable result and exceeds the calibrated range of assay 0 3014
. Missing 252 3266

LBXVCT - Blood Carbon Tetrachloride (ng/mL)

Variable Name:
LBXVCT
SAS Label:
Blood Carbon Tetrachloride (ng/mL)
English Text:
Blood Carbon Tetrachloride (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.004 to 0.018 Range of Values 2994 2994
. Missing 272 3266

LBDVCTLC - Blood Carbon Tetrachloride Comment Code

Variable Name:
LBDVCTLC
SAS Label:
Blood Carbon Tetrachloride Comment Code
English Text:
Blood Carbon Tetrachloride Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 21 21
1 Below lower detection limit 2973 2994
2 Detectable result and exceeds the calibrated range of assay 0 2994
. Missing 272 3266

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

Variable Name:
LBXVDB
SAS Label:
Blood 1,4-Dichlorobenzene (ng/mL)
English Text:
Blood 1,4-Dichlorobenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 115 Range of Values 2995 2995
. Missing 271 3266

LBDVDBLC - Blood 1,4-Dichlorobenzene Comment Code

Variable Name:
LBDVDBLC
SAS Label:
Blood 1,4-Dichlorobenzene Comment Code
English Text:
Blood 1,4-Dichlorobenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1595 1595
1 Below lower detection limit 1400 2995
2 Detectable result and exceeds the calibrated range of assay 0 2995
. Missing 271 3266

LBXVDE - Blood 1,2-Dibromoethane (ng/mL)

Variable Name:
LBXVDE
SAS Label:
Blood 1,2-Dibromoethane (ng/mL)
English Text:
Blood 1,2-Dibromoethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.011 0.011 2906 2906
. Missing 360 3266

LBDVDELC - Blood 1,2-Dibromoethane Comment Code

Variable Name:
LBDVDELC
SAS Label:
Blood 1,2-Dibromoethane Comment Code
English Text:
Blood 1,2-Dibromoethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2906 2906
2 Detectable result and exceeds the calibrated range of assay 0 2906
. Missing 360 3266

LBXVDEE - Blood Diethyl Ether (ng/mL)

Variable Name:
LBXVDEE
SAS Label:
Blood Diethyl Ether (ng/mL)
English Text:
Blood Diethyl Ether (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 0.564 Range of Values 2961 2961
. Missing 305 3266

LBDVEELC - Blood Diethyl Ether Comment Code

Variable Name:
LBDVEELC
SAS Label:
Blood Diethyl Ether Comment Code
English Text:
Blood Diethyl Ether Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 8 8
1 Below lower detection limit 2953 2961
2 Detectable result and exceeds the calibrated range of assay 0 2961
. Missing 305 3266

LBXVDX - Blood 1,4-Dioxane (ng/mL)

Variable Name:
LBXVDX
SAS Label:
Blood 1,4-Dioxane (ng/mL)
English Text:
Blood 1,4-Dioxane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.354 to 0.354 Range of Values 2884 2884
. Missing 382 3266

LBDVDXLC - Blood 1,4-Dioxane Comment Code

Variable Name:
LBDVDXLC
SAS Label:
Blood 1,4-Dioxane Comment Code
English Text:
Blood 1,4-Dioxane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2884 2884
2 Detectable result and exceeds the calibrated range of assay 0 2884
. Missing 382 3266

LBXVEA - Blood Ethyl Acetate (ng/mL)

Variable Name:
LBXVEA
SAS Label:
Blood Ethyl Acetate (ng/mL)
English Text:
Blood Ethyl Acetate (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.112 to 142 Range of Values 2893 2893
. Missing 373 3266

LBDVEALC - Blood Ethyl Acetate Comment Code

Variable Name:
LBDVEALC
SAS Label:
Blood Ethyl Acetate Comment Code
English Text:
Blood Ethyl Acetate Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 75 75
1 Below lower detection limit 2818 2893
2 Detectable result and exceeds the calibrated range of assay 0 2893
. Missing 373 3266

LBXVEB - Blood Ethylbenzene (ng/mL)

Variable Name:
LBXVEB
SAS Label:
Blood Ethylbenzene (ng/mL)
English Text:
Blood Ethylbenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.017 to 11.2 Range of Values 2988 2988
. Missing 278 3266

LBDVEBLC - Blood Ethylbenzene Comment Code

Variable Name:
LBDVEBLC
SAS Label:
Blood Ethylbenzene Comment Code
English Text:
Blood Ethylbenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1095 1095
1 Below lower detection limit 1893 2988
2 Detectable result and exceeds the calibrated range of assay 0 2988
. Missing 278 3266

LBXVEC - Blood Chloroethane (ng/mL)

Variable Name:
LBXVEC
SAS Label:
Blood Chloroethane (ng/mL)
English Text:
Blood Chloroethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.032 to 0.505 Range of Values 2976 2976
. Missing 290 3266

LBDVECLC - Blood Chloroethane Comment Code

Variable Name:
LBDVECLC
SAS Label:
Blood Chloroethane Comment Code
English Text:
Blood Chloroethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 7 7
1 Below lower detection limit 2969 2976
2 Detectable result and exceeds the calibrated range of assay 0 2976
. Missing 290 3266

LBXVFN - Blood Furan (ng/mL)

Variable Name:
LBXVFN
SAS Label:
Blood Furan (ng/mL)
English Text:
Blood Furan (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.018 to 0.605 Range of Values 3017 3017
. Missing 249 3266

LBDVFNLC - Blood Furan Comment Code

Variable Name:
LBDVFNLC
SAS Label:
Blood Furan Comment Code
English Text:
Blood Furan Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 718 718
1 Below lower detection limit 2299 3017
2 Detectable result and exceeds the calibrated range of assay 0 3017
. Missing 249 3266

LBXVIBN - Blood Isobutyronitrile (ng/mL)

Variable Name:
LBXVIBN
SAS Label:
Blood Isobutyronitrile (ng/mL)
English Text:
Blood Isobutyronitrile (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 1.04 Range of Values 2938 2938
. Missing 328 3266

LBDVIBLC - Blood Isobutyronitrile Comment Code

Variable Name:
LBDVIBLC
SAS Label:
Blood Isobutyronitrile Comment Code
English Text:
Blood Isobutyronitrile Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 387 387
1 Below lower detection limit 2551 2938
2 Detectable result and exceeds the calibrated range of assay 0 2938
. Missing 328 3266

LBXVIPB - Blood Isopropylbenzene (ng/mL)

Variable Name:
LBXVIPB
SAS Label:
Blood Isopropylbenzene (ng/mL)
English Text:
Blood Isopropylbenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 0.182 Range of Values 2983 2983
. Missing 283 3266

LBDVIPLC - Blood Isopropylbenzene Comment Code

Variable Name:
LBDVIPLC
SAS Label:
Blood Isopropylbenzene Comment Code
English Text:
Blood Isopropylbenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 9 9
1 Below lower detection limit 2974 2983
2 Detectable result and exceeds the calibrated range of assay 0 2983
. Missing 283 3266

LBXVMC - Blood Methylene Chloride (ng/mL)

Variable Name:
LBXVMC
SAS Label:
Blood Methylene Chloride (ng/mL)
English Text:
Blood Methylene Chloride (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.177 to 32.8 Range of Values 2953 2953
. Missing 313 3266

LBDVMCLC - Blood Methylene Chloride Comment Code

Variable Name:
LBDVMCLC
SAS Label:
Blood Methylene Chloride Comment Code
English Text:
Blood Methylene Chloride Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 13 13
1 Below lower detection limit 2940 2953
2 Detectable result and exceeds the calibrated range of assay 0 2953
. Missing 313 3266

LBXVME - Blood MTBE (ng/mL)

Variable Name:
LBXVME
SAS Label:
Blood MTBE (ng/mL)
English Text:
Blood Methyl-tert-butyl ether (MTBE) (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 0.107 Range of Values 2786 2786
. Missing 480 3266

LBDVMELC - Blood MTBE Comment Code

Variable Name:
LBDVMELC
SAS Label:
Blood MTBE Comment Code
English Text:
Blood Methyl-tert-butyl ether (MTBE) Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 133 133
1 Below lower detection limit 2653 2786
2 Detectable result and exceeds the calibrated range of assay 0 2786
. Missing 480 3266

LBXVMCP - Blood Methylcyclopentane (ng/mL)

Variable Name:
LBXVMCP
SAS Label:
Blood Methylcyclopentane (ng/mL)
English Text:
Blood Methylcyclopentane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.014 to 33.1 Range of Values 2835 2835
. Missing 431 3266

LBDVMPLC - Blood Methylcyclopentane Comment Code

Variable Name:
LBDVMPLC
SAS Label:
Blood Methylcyclopentane Comment Code
English Text:
Blood Methylcyclopentane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 54 54
1 Below lower detection limit 2781 2835
2 Detectable result and exceeds the calibrated range of assay 0 2835
. Missing 431 3266

LBXVNB - Blood Nitrobenzene (ng/mL)

Variable Name:
LBXVNB
SAS Label:
Blood Nitrobenzene (ng/mL)
English Text:
Blood Nitrobenzene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.226 to 0.226 Range of Values 2969 2969
. Missing 297 3266

LBDVNBLC - Blood Nitrobenzene Comment Code

Variable Name:
LBDVNBLC
SAS Label:
Blood Nitrobenzene Comment Code
English Text:
Blood Nitrobenzene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2969 2969
2 Detectable result and exceeds the calibrated range of assay 0 2969
. Missing 297 3266

LBXVOX - Blood o-Xylene (ng/mL)

Variable Name:
LBXVOX
SAS Label:
Blood o-Xylene (ng/mL)
English Text:
Blood o-Xylene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.017 to 6.56 Range of Values 2994 2994
. Missing 272 3266

LBDVOXLC - Blood o-Xylene Comment Code

Variable Name:
LBDVOXLC
SAS Label:
Blood o-Xylene Comment Code
English Text:
Blood o-Xylene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 1007 1007
1 Below lower detection limit 1987 2994
2 Detectable result and exceeds the calibrated range of assay 0 2994
. Missing 272 3266

LBXVTC - Blood Trichloroethene (ng/mL)

Variable Name:
LBXVTC
SAS Label:
Blood Trichloroethene (ng/mL)
English Text:
Blood Trichloroethene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.008 to 0.15 Range of Values 3017 3017
. Missing 249 3266

LBDVTCLC - Blood Trichloroethene Comment Code

Variable Name:
LBDVTCLC
SAS Label:
Blood Trichloroethene Comment Code
English Text:
Blood Trichloroethene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 20 20
1 Below lower detection limit 2997 3017
2 Detectable result and exceeds the calibrated range of assay 0 3017
. Missing 249 3266

LBXVTE - Blood 1,1,1-Trichloroethane (ng/mL)

Variable Name:
LBXVTE
SAS Label:
Blood 1,1,1-Trichloroethane (ng/mL)
English Text:
Blood 1,1,1-Trichloroethane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.007 to 1.09 Range of Values 3006 3006
. Missing 260 3266

LBDVTELC - Blood 1,1,1-Trichloroethane Comment Code

Variable Name:
LBDVTELC
SAS Label:
Blood 1,1,1-Trichloroethane Comment Code
English Text:
Blood 1,1,1-Trichloroethane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 22 22
1 Below lower detection limit 2984 3006
2 Detectable result and exceeds the calibrated range of assay 0 3006
. Missing 260 3266

LBXVTFT - Blood aaa - Trifluorotoluene (ng/mL)

Variable Name:
LBXVTFT
SAS Label:
Blood aaa - Trifluorotoluene (ng/mL)
English Text:
Blood aaa - Trifluorotoluene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 0.028 Range of Values 3002 3002
. Missing 264 3266

LBDVFTLC - Blood aaa -Trifluorotoluene Comment Code

Variable Name:
LBDVFTLC
SAS Label:
Blood aaa -Trifluorotoluene Comment Code
English Text:
Blood aaa -Trifluorotoluene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 3002 3002
2 Detectable result and exceeds the calibrated range of assay 0 3002
. Missing 264 3266

LBXVTHF - Blood Tetrahydrofuran (ng/mL)

Variable Name:
LBXVTHF
SAS Label:
Blood Tetrahydrofuran (ng/mL)
English Text:
Blood Tetrahydrofuran (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.088 to 1.22 Range of Values 2920 2920
. Missing 346 3266

LBDVHTLC - Blood Tetrahydrofuran Comment Code

Variable Name:
LBDVHTLC
SAS Label:
Blood Tetrahydrofuran Comment Code
English Text:
Blood Tetrahydrofuran Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 20 20
1 Below lower detection limit 2900 2920
2 Detectable result and exceeds the calibrated range of assay 0 2920
. Missing 346 3266

LBXVTO - Blood Toluene (ng/mL)

Variable Name:
LBXVTO
SAS Label:
Blood Toluene (ng/mL)
English Text:
Blood Toluene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.018 to 18.1 Range of Values 2998 2998
. Missing 268 3266

LBDVTOLC - Blood Toluene Comment Code

Variable Name:
LBDVTOLC
SAS Label:
Blood Toluene Comment Code
English Text:
Blood Toluene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 2907 2907
1 Below lower detection limit 91 2998
2 Detectable result and exceeds the calibrated range of assay 0 2998
. Missing 268 3266

LBXVTP - Blood 1,2,3-Trichloropropane (ng/mL)

Variable Name:
LBXVTP
SAS Label:
Blood 1,2,3-Trichloropropane (ng/mL)
English Text:
Blood 1,2,3-Trichloropropane (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.028 to 0.028 Range of Values 2963 2963
. Missing 303 3266

LBDVTPLC - Blood 1,2,3-Trichloropropane Comt Code

Variable Name:
LBDVTPLC
SAS Label:
Blood 1,2,3-Trichloropropane Comt Code
English Text:
Blood 1,2,3-Trichloropropane Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2963 2963
2 Detectable result and exceeds the calibrated range of assay 0 2963
. Missing 303 3266

LBXVVB - Blood Vinyl Bromide (ng/mL)

Variable Name:
LBXVVB
SAS Label:
Blood Vinyl Bromide (ng/mL)
English Text:
Blood Vinyl Bromide (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.032 to 0.032 Range of Values 2993 2993
. Missing 273 3266

LBDVVBLC - Blood Vinyl Bromide Comment Code

Variable Name:
LBDVVBLC
SAS Label:
Blood Vinyl Bromide Comment Code
English Text:
Blood Vinyl Bromide Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 0 0
1 Below lower detection limit 2993 2993
2 Detectable result and exceeds the calibrated range of assay 0 2993
. Missing 273 3266

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

Variable Name:
LBXVXY
SAS Label:
Blood m-/p-Xylene (ng/mL)
English Text:
Blood m-/p-Xylene (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.024 to 30.5 Range of Values 3013 3013
. Missing 253 3266

LBDVXYLC - Blood m-/p-Xylene Comment Code

Variable Name:
LBDVXYLC
SAS Label:
Blood m-/p-Xylene Comment Code
English Text:
Blood m-/p-Xylene Comment Code
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above detection limit 2047 2047
1 Below lower detection limit 966 3013
2 Detectable result and exceeds the calibrated range of assay 0 3013
. Missing 253 3266