• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Laboratory Method Files
• Laboratory Quality Assurance and Monitoring
• Data Processing and Editing
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • WTSVOC2Y - VOC subsample 2 yr MEC Weight
  • LBXWBF - Water Bromoform (ng/mL)
  • LBDWBFLC - Water Bromoform Comment Code
  • LBXWCF - Water Chloroform (ng/mL)
  • LBDWCFLC - Water Chloroform Comment Code
  • LBXWBM - Water Bromodichloromethane (ng/mL)
  • LBDWBMLC - Water Bromodichloromethane Comment Code
  • LBXWCM - Water Dibromochloromethane (ng/mL)
  • LBDWCMLC - Water Dibromochloromethane Comment Code
  • LBXWME - Water MTBE (ng/mL)
  • LBDWMELC - Water MTBE Comment Code
  • LBXV1A - Blood 1,1-Dichloroethane (ng/mL)
  • LBDV1ALC - Blood 1,1-Dichloroethane Comment Code
  • LBXV1D - Blood 1,2-Dichlorobenzene (ng/mL)
  • LBDV1DLC - Blood 1,2-Dichlorobenzene Comment Code
  • LBXV1E - Blood 1,1-Dichloroethene (ng/mL)
  • LBDV1ELC - Blood 1,1-Dichloroethene Comment Code
  • LBXV2A - Blood 1,2-Dichloroethane (ng/mL)
  • LBDV2ALC - Blood 1,2-Dichloroethane Comment Code
  • LBXV2C - Blood cis-1,2-Dichloroethene (ng/mL)
  • LBDV2CLC - Blood cis-1,2-Dichloroethene Comt Code
  • LBXV2E - Blood 1,1,2-Trichloroethane (ng/mL)
  • LBDV2ELC - Blood 1,1,2-Trichloroethane Comment Code
  • LBXV2T - Blood trans-1,2-Dichloroethene (ng/mL)
  • LBDV2TLC - Blood trans-1,2-Dichloroethene Comt Code
  • LBXV3B - Blood 1,3-Dichlorobenzene (ng/mL)
  • LBDV3BLC - Blood 1,3-Dichlorobenzene Comment Code
  • LBXV4C - Blood Tetrachloroethene (ng/mL)
  • LBDV4CLC - Blood Tetrachloroethene Comment Code
  • LBXV4T - Blood 1,1,2,2-Tetrachloroethane (ng/mL)
  • LBDV4TLC - Blood 1,1,2,2-Tetrachloroethane Comt
  • LBXVBF - Blood Bromoform (pg/mL)
  • LBDVBFLC - Blood Bromoform Comment Code
  • LBXVBM - Blood Bromodichloromethane (pg/mL)
  • LBDVBMLC - Blood Bromodichloromethane Comment Code
  • LBXVBZ - Blood Benzene (ng/mL)
  • LBDVBZLC - Blood Benzene Comment Code
  • LBXVCB - Blood Chlorobenzene (ng/mL)
  • LBDVCBLC - Blood Chlorobenzene Comment Code
  • LBXVCF - Blood Chloroform (pg/mL)
  • LBDVCFLC - Blood Chloroform Comment Code
  • LBXVCM - Blood Dibromochloromethane (pg/mL)
  • LBDVCMLC - Blood Dibromochloromethane Comment Code
  • LBXVCT - Blood Carbon Tetrachloride (ng/mL)
  • LBDVCTLC - Blood Carbon Tetrachloride Comment Code
  • LBXVDB - Blood 1,4-Dichlorobenzene (ng/mL)
  • LBDVDBLC - Blood 1,4-Dichlorobenzene Comment Code
  • LBXVDM - Blood Dibromomethane (ng/mL)
  • LBDVDMLC - Blood Dibromomethane Comment Code
  • LBXVDP - Blood 1,2-Dichloropropane (ng/mL)
  • LBDVDPLC - Blood 1,2-Dichloropropane Comment Code
  • LBXVEB - Blood Ethylbenzene (ng/mL)
  • LBDVEBLC - Blood Ethylbenzene Comment Code
  • LBXVHE - Blood Hexachloroethane (ng/mL)
  • LBDVHELC - Blood Hexachloroethane Comment Code
  • LBXVMC - Blood Methylene Chloride (ng/mL)
  • LBDVMCLC - Blood Methylene Chloride Comment Code
  • LBXVME - Blood MTBE (pg/mL)
  • LBDVMELC - Blood MTBE Comment Code
  • LBXVOX - Blood o-Xylene (ng/mL)
  • LBDVOXLC - Blood o-Xylene Comment Code
  • LBXVST - Blood Styrene (ng/mL)
  • LBDVSTLC - Blood Styrene Comment Code
  • LBXVTC - Blood Trichloroethene (ng/mL)
  • LBDVTCLC - Blood Trichloroethene Comment Code
  • LBXVTE - Blood 1,1,1-Trichloroethane (ng/mL)
  • LBDVTELC - Blood 1,1,1-Trichloroethane Comment Code
  • LBXVTO - Blood Toluene (ng/mL)
  • LBDVTOLC - Blood Toluene Comment Code
  • LBXVXY - Blood m-/p-Xylene (ng/mL)
  • LBDVXYLC - Blood m-/p-Xylene Comment Code
  • LBX2DF - Blood 2,5-Dimethylfuran (ng/mL)
  • LBD2DFLC - Blood 2,5-Dimethylfuran Comment Code
  • LBXV2P - Blood 1,2-Dibromo-3-chloropropane(ng/mL)
  • LBDV2PLC - Blood 1,2-Dibromo-3-chloropropane Comt
  • LBXVNB - Blood Nitrobenzene (ng/mL)
  • LBDVNBLC - Blood Nitrobenzene Comment Code
  • VTQ210 - Attached garage?
  • VTQ220 - Private well?
  • VTQ230A - Toilet bowl deodorizers?
  • VTQ230B - Moth balls or crystals?
  • VTQ240A - Pump gas into a car or motor vehicle?
  • VTQ240B - How long ago did you pump gas?
  • VTQ250A - Spend time at swimming pool?
  • VTQ250B - How long ago at swimming pool?
  • VTQ260A - Visit a dry cleaning shop?
  • VTQ260B - Spend 10 minutes near cigarette smoke?
  • VTQ270A - Take a hot shower?
  • VTQ270B - How long since hot shower?
  • VTQ280A - Breathe fumes from paints?
  • VTQ280B - Breathe fumes from degreasing cleaners?
  • VTQ280C - Breathe fumes from diesel fuel?
  • VTQ280D - Breathe fumes from paint thinner?
  • VTQ280E - Breathe fumes from drycleaning fluid?
  • VTQ280F - Breathe fumes from fingernail polish?
  • VTQ280G - Breathe fumes from glue?
  • VTQ280H - Breathe fumes from varnish?

National Health and Nutrition Examination Survey

2003-2004 Data Documentation, Codebook, and Frequencies

Volatile Organic Compounds - Blood, Water, & Related Questionnaire Items (L04VOC_C)

Data File: L04VOC_C.xpt

First Published: August 2008

Last Revised: February 2019

Component Description

Both the lab data and questionnaire items will be released in this file.

Volatile Organic Compound Questions:

The volatile organic compound section of the Mobile Examination Center (MEC) Interview and Phlebotomy Component (PH) provide personal interview data.

Volatile Organic Compounds (Human 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, and because of human health concerns, 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 paints. In the past, 1,1,1-trichloroethane was used as a dry cleaning agent, insect fumigant, and solvent in consumer products; methylene chloride, perchloroethylene, and trichloroethene are other VOCs that were widely used in the past.

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. Benzene, toluene, ethylbenzene, xylene, and styrene, collectively referred to as BTEXS, are components of tobacco smoke and along with 2,5-dimethyl furan, these VOCs are usually detected in blood of cigarette smokers at higher levels than in non-smokers. Chlorobenzene (monochlorobenzene) and the three dichlorobenzenes are halogenated aromatic hydrocarbons pirmarily used in industrial and chemical synthetic processes. Chlorobenzene has been used to produce DDT, phenol, and nitrobenzene. The dichlorobenzenes are also chemical intermediates in 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.

Inhalation is the most common VOC exposure route for the general population, including indoor sources from such as paints, adhesives, cleaning solutions, and aerosolized insecticide sprays; from industries producing these solvents; and from 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.

Volatile Organic Compounds (Home Tap Water):

In addition to assessing levels of VOCs in blood, VOC levels were measured in home tap water specimens provided by NHANES participants. Specifically, disinfection by-products (DBPs) and the fuel additive methyl tertiary-butyl ether (MTBE) are measured in these samples.

Eligible Sample

Participants aged 20 to 59 from a one-half sample were eligible.

Description of Laboratory Methodology

Interview Setting and Mode of Administration

The questions were asked during the physical examination, in the mobile examination center (MEC). The questions were administered by the phlebotomist or the MEC interviewers.

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. 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. 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 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

Additional VOCs were measured in human blood using SPME in conjunction with gas chromatography and bench top quadrupole mass spectrometer. 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.

Refer to the Laboratory Method Files section for detailed laboratory procedure manual(s) of the methods used.

There were no changes to the lab method, lab equipment, or lab site for this component in the NHANES 2003-2004 cycle.

Laboratory Method Files

Lab 04 Volatile Organic Compounds in Blood (Updated January 2017)

Lab 04 Volatile Organic Compounds in Water (August 2008)

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 Amendments 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 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.

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% of all specimens.

NCHS developed and distributed a quality control protocol for all the 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 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.

All QC procedures recommended by the manufacturers were followed. Reported results for all assays meet the CDC/NCEH Tobacco and Volatile Branch 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 2003-2004 Laboratory Data Overview for general information on NHANES laboratory data.

Subsample Weights

Whole blood VOCs were measured in a one-half subsample of persons 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 2003-2004 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 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 URX (ex., LBX2DF) provides the analytic result for that analyte.

Lower Limit of Detection (LLOD, in ng/mL) for 2005-2006 Whole Blood VOCs:

VARIABLE NAME	SAS LABEL	LLOD
LBX2DF	Blood 2,5-dimethylfuran (ng/mL)	0.0110
LBXV1A	Blood 1,1-dichloroethane (ng/mL)	0.0100
LBXV1D	Blood 1,2-dichlorobenzene (ng/mL)	0.1000
LBXV1E	Blood 1,1-dichloroethene (ng/mL)	0.0090
LBXV2A	Blood 1,2-dichloroethane (ng/mL)	0.0100
LBXV2C	Blood cis 1,2-dichloroethene (ng/mL)	0.0100
LBXV2E	Blood 1,1,2-trichloroethane (ng/mL)	0.0100
LBXV2P	Blood 1,2 Dibromo-3-chloropropane (ng/mL)	0.1000
LBXV2T	Blood trans-1,2-dichloroethene (ng/mL)	0.0100
LBXV3B	Blood 1,3-dichlorobenzene (ng/mL)	0.0500
LBXV4C	Blood tetrachloroethene (ng/mL)	0.0480
LBXV4E	Blood 1,1,2,2-tetrachloroethane (ng/mL)	0.0100
LBXVBF	Blood Bromoform (pg/mL)	1.5000
LBXVBM	Blood Bromodichloromethane (pg/mL)	0.6200
LBXVBZ	Blood benzene (ng/mL)	0.0240
LBXVCB	Blood chlorobenzene (ng/mL)	0.0110
LBXVCF	Blood Chloroform (pg/mL)	2.1000
LBXVCM	Blood Dibromochloromethane (pg/mL)	0.6200
LBXVCT	Blood carbon tetrachloride (ng/mL)	0.0500
LBXVDB	Blood 1,4-dichlorobenzene (ng/mL)	0.1200
LBXVDM	Blood Dibromomethane (ng/mL)	0.0300
LBXVDP	Blood 1,2-dichloropropane (ng/mL)	0.0080
LBXVEB	Blood ethylbenzene (ng/mL)	0.0240
LBXVHE	Blood Hexachloroethane (ng/mL)	0.0110
LBXVMC	Blood methylene chloride(ng/mL)	0.2500
LBXVME	Blood MTBE (pg/mL)	1.4000
LBXVNB	Blood nitrobenzene (ng/mL)	0.3000
LBXVOX	Blood o-xylene (ng/mL)	0.0240
LBXVST	Blood styrene (ng/mL)	0.0300
LBXVTC	Blood trichloroethene (ng/mL)	0.0120
LBXVTE	Blood 1,1,1-trichloroethane (ng/mL)	0.0500
LBXVTO	Blood toluene (ng/mL)	0.0250
LBXVXY	Blood m-/p-Xylene (ng/mL)	0.0340

 

References

• Blount BC, Kobelski RJ, McElprang DO, Ashley DL, Morrow JC, Chambers DM, Cardinali FL (2006) Quantification of 31 Volatile Organic Compounds in Whole Blood Using Solid-Phase Microextraction and Gas Chromatography/Mass Spectrometry. J. Chromatography B. 832(2):292-301.
• Bonin MA, Silva LK, Smith MM, Ashley DL, Blount BC (2005) Measurement of trihalomethanes and methyl tert-butyl ether in whole blood using gas chromatography with high-resolution mass spectrometry. J Anal Toxicol. 29(2):81-89.
• Cardinali FL, Ashley DL, Morrow JC, Moll DM, Blount BC (2004), Measurement of Trihalomethanes and Methyl Tertiary-Butyl Ether in Tap Water Using Solid-Phase Microextraction GC/MS, Journal of Chromatographic Sciences, 42:200-206.
• 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.
• Morandi MT, Stock TH. Personal Exposures to Toxic Air Pollutants, Vol. 2. Houston, TX; The University of Texas – Houston, Health Science Center, School of Public Health: 1998.
• U.S. Occupational Safety and Health Administration (OSHA). Organic Vapors, Method 07 in Analytical Methods Manual. Salt Lake City, Utah; OSHA Analytical Laboratory: 1985.
• 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