National Health and Nutrition Examination Survey

2015-2016 Data Documentation, Codebook, and Frequencies

Volatile Organic Compounds and Trihalomethanes/MTBE - Blood (VOCWB_I)

Data File: VOCWB_I.xpt

First Published: September 2018

Last Revised: NA

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

Examined participants aged 12 years and older from a one-half sample were eligible.

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 the 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 12 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

Caudill, S.P., Schleicher, R.L., Pirkle, J.L. Multi-rule quality control for the age-related eye disease study. Statist. Med. (2008) 27(20):4094-40106.
Westgard J.O., Barry P.L., Hunt M.R., Groth T. A multi-rule Shewhart chart for quality control in clinical chemistry. Clin Chem (1981) 27:493-501.

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 12 YEARS - 150 YEARS

WTSVOC2Y - VOC Subsample Weight

Variable Name:: WTSVOC2Y
SAS Label:: VOC Subsample Weight
English Text:: VOC Subsample Weight
Target:: Both males and females 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0 to 499733.23816	Range of Values	3394	3394
.	Missing	0	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.008 to 1.45	Range of Values	3083	3083
.	Missing	311	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	522	522
1	Below lower detection limit	2561	3083
2	Detectable result and exceeds the calibrated range of assay	0	3083
.	Missing	311	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028	0.028	3082	3082
.	Missing	312	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3082	3082
2	Detectable result and exceeds the calibrated range of assay	0	3082
.	Missing	312	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.086 to 26.4	Range of Values	2840	2840
.	Missing	554	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	19	19
1	Below lower detection limit	2821	2840
2	Detectable result and exceeds the calibrated range of assay	0	2840
.	Missing	554	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.071 to 0.767	Range of Values	2991	2991
.	Missing	403	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	34	34
1	Below lower detection limit	2957	2991
2	Detectable result and exceeds the calibrated range of assay	0	2991
.	Missing	403	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.071 to 0.827	Range of Values	3000	3000
.	Missing	394	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	5	5
1	Below lower detection limit	2995	3000
2	Detectable result and exceeds the calibrated range of assay	0	3000
.	Missing	394	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.018 to 0.092	Range of Values	3005	3005
.	Missing	389	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	1	1
1	Below lower detection limit	3004	3005
2	Detectable result and exceeds the calibrated range of assay	0	3005
.	Missing	389	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.007 to 0.095	Range of Values	3035	3035
.	Missing	359	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	99	99
1	Below lower detection limit	2936	3035
2	Detectable result and exceeds the calibrated range of assay	0	3035
.	Missing	359	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.018 to 0.018	Range of Values	3041	3041
.	Missing	353	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3041	3041
2	Detectable result and exceeds the calibrated range of assay	0	3041
.	Missing	353	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.034 to 16	Range of Values	3089	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	189	189
1	Below lower detection limit	2900	3089
2	Detectable result and exceeds the calibrated range of assay	0	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.006 to 0.139	Range of Values	3046	3046
.	Missing	348	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	259	259
1	Below lower detection limit	2787	3046
2	Detectable result and exceeds the calibrated range of assay	0	3046
.	Missing	348	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.004 to 0.068	Range of Values	3077	3077
.	Missing	317	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	513	513
1	Below lower detection limit	2564	3077
2	Detectable result and exceeds the calibrated range of assay	0	3077
.	Missing	317	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.017 to 2.75	Range of Values	3038	3038
.	Missing	356	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	1215	1215
1	Below lower detection limit	1823	3038
2	Detectable result and exceeds the calibrated range of assay	0	3038
.	Missing	356	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.106 to 1.92	Range of Values	3028	3028
.	Missing	366	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	167	167
1	Below lower detection limit	2861	3028
2	Detectable result and exceeds the calibrated range of assay	0	3028
.	Missing	366	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.014 to 12.7	Range of Values	2965	2965
.	Missing	429	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	46	46
1	Below lower detection limit	2919	2965
2	Detectable result and exceeds the calibrated range of assay	0	2965
.	Missing	429	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.008 to 0.043	Range of Values	3070	3070
.	Missing	324	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	2	2
1	Below lower detection limit	3068	3070
2	Detectable result and exceeds the calibrated range of assay	0	3070
.	Missing	324	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.006 to 0.594	Range of Values	2989	2989
.	Missing	405	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	1696	1696
1	Below lower detection limit	1293	2989
2	Detectable result and exceeds the calibrated range of assay	0	2989
.	Missing	405	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.004 to 0.071	Range of Values	3087	3087
.	Missing	307	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	435	435
1	Below lower detection limit	2652	3087
2	Detectable result and exceeds the calibrated range of assay	0	3087
.	Missing	307	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.004 to 0.018	Range of Values	3067	3067
.	Missing	327	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	21	21
1	Below lower detection limit	3046	3067
2	Detectable result and exceeds the calibrated range of assay	0	3067
.	Missing	327	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 115	Range of Values	3067	3067
.	Missing	327	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	1658	1658
1	Below lower detection limit	1409	3067
2	Detectable result and exceeds the calibrated range of assay	0	3067
.	Missing	327	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.011	0.011	2986	2986
.	Missing	408	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	2986	2986
2	Detectable result and exceeds the calibrated range of assay	0	2986
.	Missing	408	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 0.659	Range of Values	3029	3029
.	Missing	365	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	7	7
1	Below lower detection limit	3022	3029
2	Detectable result and exceeds the calibrated range of assay	0	3029
.	Missing	365	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.354 to 0.354	Range of Values	2950	2950
.	Missing	444	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	2950	2950
2	Detectable result and exceeds the calibrated range of assay	0	2950
.	Missing	444	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.112 to 142	Range of Values	2965	2965
.	Missing	429	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	55	55
1	Below lower detection limit	2910	2965
2	Detectable result and exceeds the calibrated range of assay	0	2965
.	Missing	429	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.017 to 11.2	Range of Values	3059	3059
.	Missing	335	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	810	810
1	Below lower detection limit	2249	3059
2	Detectable result and exceeds the calibrated range of assay	0	3059
.	Missing	335	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.032 to 0.505	Range of Values	3042	3042
.	Missing	352	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	6	6
1	Below lower detection limit	3036	3042
2	Detectable result and exceeds the calibrated range of assay	0	3042
.	Missing	352	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.018 to 0.605	Range of Values	3089	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	409	409
1	Below lower detection limit	2680	3089
2	Detectable result and exceeds the calibrated range of assay	0	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 1.04	Range of Values	3008	3008
.	Missing	386	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	208	208
1	Below lower detection limit	2800	3008
2	Detectable result and exceeds the calibrated range of assay	0	3008
.	Missing	386	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 0.051	Range of Values	3058	3058
.	Missing	336	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	6	6
1	Below lower detection limit	3052	3058
2	Detectable result and exceeds the calibrated range of assay	0	3058
.	Missing	336	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.177 to 32.8	Range of Values	3027	3027
.	Missing	367	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	12	12
1	Below lower detection limit	3015	3027
2	Detectable result and exceeds the calibrated range of assay	0	3027
.	Missing	367	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.007 to 0.107	Range of Values	2858	2858
.	Missing	536	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	131	131
1	Below lower detection limit	2727	2858
2	Detectable result and exceeds the calibrated range of assay	0	2858
.	Missing	536	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.014 to 33.1	Range of Values	2899	2899
.	Missing	495	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	51	51
1	Below lower detection limit	2848	2899
2	Detectable result and exceeds the calibrated range of assay	0	2899
.	Missing	495	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.226 to 0.226	Range of Values	3037	3037
.	Missing	357	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3037	3037
2	Detectable result and exceeds the calibrated range of assay	0	3037
.	Missing	357	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.017 to 6.56	Range of Values	3065	3065
.	Missing	329	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	758	758
1	Below lower detection limit	2307	3065
2	Detectable result and exceeds the calibrated range of assay	0	3065
.	Missing	329	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.008 to 0.15	Range of Values	3089	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	21	21
1	Below lower detection limit	3068	3089
2	Detectable result and exceeds the calibrated range of assay	0	3089
.	Missing	305	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.007 to 1.09	Range of Values	3079	3079
.	Missing	315	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	21	21
1	Below lower detection limit	3058	3079
2	Detectable result and exceeds the calibrated range of assay	0	3079
.	Missing	315	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 0.028	Range of Values	3077	3077
.	Missing	317	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3077	3077
2	Detectable result and exceeds the calibrated range of assay	0	3077
.	Missing	317	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.088 to 1.22	Range of Values	2979	2979
.	Missing	415	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	17	17
1	Below lower detection limit	2962	2979
2	Detectable result and exceeds the calibrated range of assay	0	2979
.	Missing	415	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.018 to 11.5	Range of Values	3078	3078
.	Missing	316	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	2959	2959
1	Below lower detection limit	119	3078
2	Detectable result and exceeds the calibrated range of assay	0	3078
.	Missing	316	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.028 to 0.028	Range of Values	3036	3036
.	Missing	358	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3036	3036
2	Detectable result and exceeds the calibrated range of assay	0	3036
.	Missing	358	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.032 to 0.032	Range of Values	3063	3063
.	Missing	331	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	0	0
1	Below lower detection limit	3063	3063
2	Detectable result and exceeds the calibrated range of assay	0	3063
.	Missing	331	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative	Skip to Item
0.024 to 30.5	Range of Values	3085	3085
.	Missing	309	3394

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 12 YEARS - 150 YEARS

Code or Value	Value Description	Count	Cumulative
0	At or above detection limit	1928	1928
1	Below lower detection limit	1157	3085
2	Detectable result and exceeds the calibrated range of assay	0	3085
.	Missing	309	3394

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