• Component Description
• Eligible Sample
• Description of Laboratory Methodology
• Laboratory Quality Assurance and Monitoring
• Laboratory Quality Assurance and Monitoring
• Analytic Notes
• Analytic Notes
• References
• Codebook
  • SEQN - Respondent sequence number
  • WTSC2YR - Two-year MEC weights of subsample C
  • LBX044 - PCB44 (ng/g)
  • LBX044LA - PCB44 Lipid Adj (ng/g)
  • LBD044LC - PCB44 Comment Code
  • LBX049 - PCB49 (ng/g)
  • LBX049LA - PCB49 Lipid Adj (ng/g)
  • LBD049LC - PCB49 Comment Code
  • LBX052 - PCB52 (ng/g)
  • LBX052LA - PCB52 Lipid Adj (ng/g)
  • LBD052LC - PCB52 Comment Code
  • LBX087 - PCB87 (ng/g)
  • LBX087LA - PCB87 Lipid Adj (ng/g)
  • LBD087LC - PCB87 Comment Code
  • LBX099 - PCB99 (ng/g)
  • LBX099LA - PCB99 Lipid Adj (ng/g)
  • LBD099LC - PCB99 Comment Code
  • LBX101 - PCB101 (ng/g)
  • LBX101LA - PCB101 Lipid Adj (ng/g)
  • LBD101LC - PCB101 Comment Code
  • LBX110 - PCB110 (ng/g)
  • LBX110LA - PCB110 Lipid Adj (ng/g)
  • LBD110LC - PCB110 Comment Code
  • LBX128 - PCB128 (ng/g)
  • LBX128LA - PCB128 Lipid Adj (ng/g)
  • LBD128LC - PCB128 Comment Code
  • LBX138 - PCB138 & 158 (ng/g)
  • LBX138LA - PCB138 & 158 Lipid Adj (ng/g)
  • LBD138LC - PCB138 & 158 Comment Code
  • LBX146 - PCB146 (ng/g)
  • LBX146LA - PCB146 Lipid Adj (ng/g)
  • LBD146LC - PCB146 Comment Code
  • LBX149 - PCB149 (ng/g)
  • LBX149LA - PCB149 Lipid Adj (ng/g)
  • LBD149LC - PCB149 Comment Code
  • LBX151 - PCB151 (ng/g)
  • LBX151LA - PCB151 Lipid Adj (ng/g)
  • LBD151LC - PCB151 Comment Code
  • LBX153 - PCB153 (ng/g)
  • LBX153LA - PCB153 Lipid Adj (ng/g)
  • LBD153LC - PCB153 Comment Code
  • LBX170 - PCB170 (ng/g)
  • LBX170LA - PCB170 Lipid Adj (ng/g)
  • LBD170LC - PCB170 Comment Code
  • LBX172 - PCB172 (ng/g)
  • LBX172LA - PCB172 Lipid Adj (ng/g)
  • LBD172LC - PCB172 Comment Code
  • LBX177 - PCB177 (ng/g)
  • LBX177LA - PCB177 Lipid Adj (ng/g)
  • LBD177LC - PCB177 Comment Code
  • LBX178 - PCB178 (ng/g)
  • LBX178LA - PCB178 Lipid Adj (ng/g)
  • LBD178LC - PCB178 Comment Code
  • LBX180 - PCB180 (ng/g)
  • LBX180LA - PCB180 Lipid Adj (ng/g)
  • LBD180LC - PCB180 Comment Code
  • LBX183 - PCB183 (ng/g)
  • LBX183LA - PCB183 Lipid Adj (ng/g)
  • LBD183LC - PCB183 Comment Code
  • LBX187 - PCB187 (ng/g)
  • LBX187LA - PCB187 Lipid Adj (ng/g)
  • LBD187LC - PCB187 Comment Code
  • LBX194 - PCB194 (ng/g)
  • LBX194LA - PCB194 Lipid Adj (ng/g)
  • LBD194LC - PCB194 Comment Code
  • LBX195 - PCB195 (ng/g)
  • LBX195LA - PCB195 Lipid Adj (ng/g)
  • LBD195LC - PCB195 Comment Code
  • LBX196 - PCB196 & 203 (ng/g)
  • LBX196LA - PCB196 & 203 Lipid Adj (ng/g)
  • LBD196LC - PCB196 & 203 Comment Code
  • LBD199 - PCB199 (ng/g)
  • LBD199LA - PCB199 Lipid Adj (ng/g)
  • LBD199LC - PCB199 Comment Code
  • LBX206 - PCB206 (ng/g)
  • LBX206LA - PCB206 Lipid Adj (ng/g)
  • LBD206LC - PCB206 Comment Code
  • LBX209 - PCB209 (ng/g)
  • LBX209LA - PCB209 Lipid Adj (ng/g)
  • LBD209LC - PCB209 Comment Code

National Health and Nutrition Examination Survey

2003-2004 Data Documentation, Codebook, and Frequencies

Non-dioxin-like Polychlorinated Biphenyls (L28NPB_C)

Data File: L28NPB_C.xpt

First Published: April 2008

Last Revised: NA

Component Description

Polychlorinated biphenyls (PCBs) are a class of chlorinated aromatic hydrocarbon chemicals that once were used as heat-exchanger, transformer, and hydraulic fluids, and as additives to paints, oils, joint caulking, and floor tiles. The different types of PCB chemicals are known as congeners, which are compounds that are distinguished by the number of chlorine atoms and their location on the biphenyl structure. Peak production occurred in the early 1970s, and production was banned in the United States after 1979. More than 1.5 billion pounds of PCBs were manufactured in the United States prior to 1977. Continued concern about these chemicals is because of their persistence in the environment and accumulation in wildlife and the animal food chain. PCBs enter the food chain by a variety of routes, including migration into food from external sources, contamination of animal feeds, and accumulation in the fatty tissues of animals. PCBs are found at higher concentrations in fatty foods (e.g., dairy products and fish) and food is the main source of exposure for the general population. The transfer of PCBs from mother to infant via breast milk is another important source of exposure. Exposure to these chemicals nearly always occurs as mixtures rather than as individual PCBs.

Eligible Sample

Participants aged 12 years and older who met the subsample requirements.

Description of Laboratory Methodology

Serum specimens (1–1.5 mL) to be analyzed for PCBs and persistent pesticides are spiked with ¹³C₁₂-labeled internal standards and the analytes of interest are isolated in hexane using a C18 solid phase extraction (SPE) procedure followed by extraction through neutral silica and Florosil SPE columns. PCBs and pesticides are eluted from the Florosil column with hexane and 1:1 dichloromethane /hexane. For PCBs and pesticides, each analytical run consists of nine unknown specimens, one method blank, and two quality control samples. Beforequantification, the vials are reconstituted with 10μL ¹³C-labeled external standard. Sample extracts are then analyzed simultaneously for PCBs and pesticides by HRGC/ID-HRMS where 1 μL is injected, using a GC Pal (Leap Technology) auto sampler, into a Hewlett-Packard 6890 gas chromatograph operated in the splitless injection mode with a flow of 1 mL/min helium through a DB-5ms capillary column (30 m x0.25 mm x0.25 μm film thickness) where analytes are separated prior to entering a Thermo Finnigan MAT95 XP (5 kV) magnetic sector mass spectrometer operated in EI mode at 40 eV, using selected ion monitoring (SIM) at 10,000 resolving power (10% valley). Two ion current responsescorresponding to two masses are monitored for each native (¹²C) compound and it corresponding ¹³C-internal standard. The instrumental response factor for each analyte is calculated as the sum of the two ¹²C-isomers divided by the sum of two ¹³C-isomers.

Calibration of mass spectrometer response factor vs. concentration is performed using calibration standards containing known concentrations of each ¹²C compound and its corresponding ¹³C internal standard. The concentration of each analyte is derived by interpolation from individual linear calibration curves and is adjusted for sample weight. The validity of all mass spectrometry data are evaluated using a variety of established criteria, such as signal-to-noise ratio ≥ 3 for the smallest native ion mass, instrument resolving power ≥ 10,000, chromatographic isomer specificity index with 95% limits, relative retention time ratio of native to isotopically labeled analyte within 3 parts-per-thousand compared to a standard, response ratios of the two 12C and 13C ions must be within ± 20 % of their theoretical values and analyte recovery ≥10 % and ≤ 120%. In addition, the calculated mean and range of each analyte in the quality control sample must be within their respectiveconfidence intervals. The method detection limit (MDL) for each analyteis calculated correcting for sample weight and recovery. The total lipidcontent of each specimen is estimated from its total cholesterol and triglycerides values using a “summation” method. Analytical results for PCBs and pesticides are reported on a whole-weight [ng/g or parts-per-billion (ppb)] and lipid-adjusted basis [ng/g or ppb]. International toxicity equivalents (I-TEQs) are also reported for PCDDs, PCDFs, cPCBs andother “dioxin-like” PCBs, based on the WHO-TEF system. Prior to reporting results, all quality control (QC) data undergo a final review bya Division of Laboratory Science quality control officer.

Laboratory Quality Assurance and Monitoring

Serum specimens are processed, stored, and shipped to the Division ofLaboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention for analysis.

Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Vials are stored under appropriate frozen (–20°C) conditions until they are shipped to National Center for Environmental Health for testing.

Mobile Examination Centers (MECs)

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

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

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the 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 2.0%of all specimens.

NCEH developed and distributed a quality control protocolfor all the laboratories which outlined the Westgard rules used when running NHANES specimens. Any problems encountered during shipping or receipt of specimens, instrument calibration, reagents, and any special considerations are submitted to NCHS and Westat. Summary statistics for each control pool, QC graphs, are reviewed by NCHS for trends or shifts in the data. The laboratories are required to explain any identifiedareas of concern.

All QC procedures recommended by the manufacturers were followed.Reported results for all assays meet the Division of Laboratory Sciences’ quality control and quality assurance performance criteria for accuracy and precision (similar to specifications outlined by Westgard(1981).

Laboratory Quality Assurance and Monitoring

Serum specimens are processed, stored, and shipped to the Division ofLaboratory Sciences, National Center for Environmental Health, Centers for Disease Control and Prevention for analysis.

Detailed specimen collection and processing instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM). Vials are stored under appropriate frozen (–20°C) conditions until they are shipped to National Center for Environmental Health for testing.

Mobile Examination Centers (MECs)

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

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

Analytical Laboratories

NHANES uses several methods to monitor the quality of the analyses performed by the 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 2.0% of all specimens.

NCEH developed and distributed a quality control protocolfor all the laboratories which outlined the Westgard rules used when running NHANES specimens. Any problems encountered during shipping or receipt of specimens, instrument calibration, reagents, and any special considerations are submitted to NCHS and Westat. Summary statistics for each control pool, QC graphs, are reviewed by NCHS 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 Sciences’ quality control and quality assurance performance criteria for accuracy and precision (similar to specifications outlined by Westgard(1981).

Analytic Notes

Subsample weights

Measures of non-dioxin polychlorinated biphenyls were measured in a one third subsample of persons 12 years and over. Special sample weights are required to analyze these data properly. Specific sample weights for this subsample are included in this data file and should beused when analyzing these data.

Variance estimation

The analysis of NHANES 2003-2004 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2003-2004 Demographic Data File contains demographic and 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.

Links to NHANES Data Files

This laboratory data file can be linked to the other NHANES 2003-2004data files using the unique survey participant identifier SEQN.

Detection Limits

The detection limits were variable for all of the analytes except for PCB 052(LBX052), PCB099(LBX099), PCB138(LBX138), and PCB153(LBX153), . The variable named LBD___LC indicates whetherthe result was below the limit of detection. There are two values: “0” and “1”. “0” means that the result was at or above the limit of detection. “1” indicates that the result was below the limit of detection.

The other variable named LBX___ provides the analytic result for that analyte.

The detection limit divided by the square root of 2 is the value that is provided for results that are below the limit of detection.

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

Analytic Notes

Measures of polychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), non-ortho substituted or coplanar polychlorinated biphenyls (cPCBs) are assessed in participants aged 12 years and older on a one-third subsample.

Use the special weights included in this data file when analyzing data. Read the “Special Sample Weights for this Dataset”information provided before beginning analysis.

Subsample weights

Measures ofpolychlorinated dibenzo-p-dioxins (PCDDs), dibenzofurans (PCDFs), non-ortho substituted or coplanar polychlorinated biphenyls (cPCBs) were measured in a one third subsample of persons 12 years and over. 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.

Variance estimation

The analysis of NHANES 2003-2004 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 2003-2004 Demographic Data File contains demographic and 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.

Links to NHANES Data Files

This laboratory data file can be linked to the other NHANES 2003-2004data files using the unique survey participant identifier SEQN.

Detection Limits

The detection limits were variable for all of the analytes except for PCB 052(LBX052), PCB099(LBX099), PCB138(LBX138), and PCB153(LBX153), . The variable named LBD___LC indicates whetherthe result was below the limit of detection. There are two values: “0” and “1”. “0” means that the result was at or above the limit of detection. “1” indicates that the result was below the limit of detection.

The other variable named LBX___ provides the analytic result for thatanalyte.

The detection limit divided by the square root of 2 is the value that is provided for results that are below the limit of detection.

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

References

• Akins J.R., Waldrep K., and Bernert J.T. Jr. The Estimation of Total Serum Lipids by a Completely Enzymatic 'Summation' Method. Clin. Chim. Acta. 184: 219-226 (1989).
• Barr J.B., Maggio V.L., Barr D.B., Turner W.E., Sjodin A., Sandau C.D., Pirkle J.L., Needham L.L., and Patterson D.G. Jr. New High-Resolution Mass Spectrometric Approach for the Measurement of Polychlorinated Biphenyls and Organochlorine Pesticides in Human Serum. J. Chromatography B. 2003:794;137–148.
• Burse V.B., Patterson D.G. Jr., Brock J.W., and Needham L.L. Selected Analytical Methods Used at the Centers for Disease Control and Prevention for Measuring Environmental Pollutants in Serum. Toxicology and Industrial Health 1996:12(3/4);481–498.
• Keith H.K., Crummett W., Deegan J. Jr., et al. Principles of Environmental Analysis. Anal. Chem. 55: 2210-2218 (1983).
• Keith L.H . Report Results Right, Part I. Chemtech June: 352-356 (1991).
• Keith L.H . Report Results Right, Part II. Chemtech August: 486-489 (1991).
• Lapeza C.R. Jr., Patterson D.G. Jr., Liddle J.A.. An Automated Apparatus for the Extraction andEnrichment of 2,3,7,8-TCDD in Human Adipose. Anal. Chem. 1986:58;713–716.
• Patterson D.G. Jr., Alexander L.R., Turner W.E., Isaacs S.G., and Needham L.L. (1990). The Development and Application of a High Resolution Mass Spectrometry Method for Measuring Polychlorinated Dibenzo-p-dioxins and Dibenzofurans in Serum. Chapter 9 In: Instrumentation for Trace Organic Monitoring. Clement R.E., Sui K.M., and Hill H.H. Jr., eds, Lewis Publishers.
• Patterson D.G. Jr., Fürst P., Henderson L.O., Isaacs S.G., Alexander L.R., Turner W.E., Needham L.L., and Hannon H. Partitioning of In Vivo Bound PCDDs/PCDFs among Various Compartments in Whole Blood. Chemosphere 1989:19/1-6;135–142.
• Patterson D.G. Jr., Hampton L., Lapeza C.R. Jr., et al. High-Resolution Gas Chromatographic/High-Resolution Mass Spectrometric Analysis of Human Serum on a Whole-Weight and Lipid Basis for 2,3,7,8-TCDD. Anal. Chem. 1987:59;2000–2005.
• Patterson D.G. Jr., Holler J.S., Belser W.T., Boozer E.L., Lapeza C.R. Jr., Needham L.L. Determination of 2,3,7,8-TCDD in Human Adipose Tissue on Whole Weight and Lipid Bases. Chemosphere 1987:16;935–936.
• Patterson D.G. Jr., Holler J.S., Lapeza C.R., et al. High-Resolution Gas Chromatographic/High-Resolution Mass Spectroscopic Analysis of Human Adipose Tissue for 2,3,7,8-TCDD. Anal. Chem. 1986:58;705–713.
• Patterson D.G. Jr., Isaacs S.G., Alexander L.R., Turner W.E., Hampton L., Bernert J.T., Needham L.L. (1990). Determination of Specific Polychlorinated Dibenzo-p-dioxins and Dibenzofurans . . . Volume 11 - Polychlorinated Dibenzo-p-dioxins, Dibenzofurans, and Biphenyls," C. Rappe and H.R. Buser, Eds., WHO, International Association for Research on Cancer, Lyon, France.
• Patterson D.G. Jr., Turner W.E., Alexander L.R., Isaacs S.G., and Needham L.L. The Analytical Methodology and Method Performance for the Determination of 2,3,7,8-TCDD in Serum for the Vietnam Veteran Agent Orange Validation Study, The Ranch Hand Validation and Half-Life Studies, and SelectedNIOSH Workers Studies. Chemosphere 1989:18/1-6;875–882.
• Phillips, D.L., Pirkle, J.L., Burse V.W., Bernert, J.T., Henderson, L.O., and Needham, L.L. Chlorinated Hydrocarbon Levels in Humans Serum: Effects of Fasting and Feeding.Arch. Environ. Contam. Toxicol. 18: 495-500 (1989).
• Taylor J.K. Quality Assurance of Chemical Measurements. Anal. Chem. 53: 1588A-1592A, 1596A (1981).
• Turner W., DiPietro E., Cash T.P., McClure P.C., Patterson, D.G Jr., and Shirkhan An Improved SPE Extraction and Automated Sample Cleanup Method for Serum PCDDs, PCDFs, and Coplanar PCBs. Organohalogen Compounds 1994:19;31–35.
• Turner W., DiPietro E., Lapeza C., Green V., Gill J., Patterson, D.G. , Jr. A Fast Universal Automated Cleanup System for the Isotope-Dilution High-Resolution Mass Spectrometric Analysis of PCDDs, PCDFs, Coplanar PCBs, PCB Congeners, andPersistent Pesticides from the Same Serum Sample. Organohalogen Compounds 1997:31;26–31.
• Van den Berg M, Birnbaum L, Bosveld ATC et al. Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, and PCDFs for Humans and Wildlife. Environmental Health Perspectives 106: 775-792 (1998).

Codebook and Frequencies