Table of Contents

Component Description

Aldehydes are formed as thermal degradation byproducts released into the atmosphere from the burning of organic matter such as gasoline, food flavorants, and tobacco. Aldehydes are potentially carcinogenic and mutagenic; therefore, exposure to aldehydes has raised concerns about adverse health effects in humans.

Eligible Sample

Examined participants aged 18 years and older from a one-third subsample were eligible. Additionally, to oversample adult smokers, those participants aged 18 years and older, not in the regular one-third 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 solid phase microextraction (SPME) gas chromatography (GC) and high-resolution mass spectrometry (HRMS) with selected ion mass detection and isotope-dilution techniques. This analytical method quantifies trace levels of 12 aldehydes from protein adducts in human serum.

Because aldehydes have the tendency to react with biological molecules to form various products, including Schiff base protein adducts, free aldehydes released into the headspace of biological samples from the Schiff base protein adducts at low pH (~3) are analyzed. The method reproducibly hydrolyzes aldehyde adducts covalently bound to proteins, using automation to individually incubate samples prior to analysis with hydrochloric acid (Yeo 2004). Free aldehydes are captured by the SPME fiber; desorbed into the heated GC injector; and extracted aldehydes are focused at the head of the GC column using a cryogenically cooled trap (Cryo-trap). Analytes are then separated in a capillary column and quantified using multiple ion detection (MID) with mass spectrometry. This method employs isotope dilution to quantify precisely trace amounts of aldehydes with limits of detection in the low parts per trillion range. The linear calibration curve spanned over three orders of magnitude.

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

This is a new component in the NHANES 2013-2014 cycle.

Laboratory Method Files

Serum Aldehydes Laboratory Procedure Manual (April 2019)

Laboratory Quality Assurance and Monitoring

Serum samples were processed, stored, and shipped to the 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 the 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 during “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 Sciences’ 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 2013-2014 Laboratory Data Overview for general information on NHANES laboratory data.

Subsample Weights

Serum aldehydes were measured in a special smoking subsample of persons 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 2013-2014 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 length of fast, and the time of 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., LBD4ALLC) indicates whether the result was below the limit of detection: the value “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., LBD4ALLC=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., LBX4AL) provides the analytic result for that analyte.

The lower limit of detection (LLOD, in ng/mL) for serum aldehydes:

VARIABLE NAME

SAS LABEL

LLOD

LBXBZAL

Benzaldehyde (ng/mL)

0.461

LBXCRAL

Crotonaldehyde (ng/mL)

0.147

LBXI5AL

Isopentanaldehyde (ng/mL)

0.316

LBXTLAL

o-Tolualdehyde (ng/mL)

0.142

LBX3AL

Propanaldehyde (ng/mL)

1.16

LBX4AL

Butyraldehyde (ng/mL)

0.313

LBX5AL

Pentanaldehyde (ng/mL)

0.316

LBX6AL

Hexanaldehyde (ng/mL)

0.693

LBX7AL

Heptanaldehyde (ng/mL)

0.312

LBX8AL

Octanaldehyde (ng/mL)

0.66

LBX9AL

Nonanaldehyde (ng/mL)

2.63

LBX10AL

Decanaldehyde (ng/mL)

3.9

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

WTALDS2Y - Two Year Aldehyde Smoking Weights

Variable Name:
WTALDS2Y
SAS Label:
Two Year Aldehyde Smoking Weights
English Text:
Two Year Aldehyde Smoking Weights
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 511460.1478 Range of Values 2605 2605
. Missing 0 2605

LBXBZAL - Benzaldehyde (ng/mL)

Variable Name:
LBXBZAL
SAS Label:
Benzaldehyde (ng/mL)
English Text:
Benzaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.326 to 28.2 Range of Values 1661 1661
. Missing 944 2605

LBDBZLC - Benzaldehyde Comment Code

Variable Name:
LBDBZLC
SAS Label:
Benzaldehyde Comment Code
English Text:
Benzaldehyde 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 1527 1527
1 Below lower detection limit 134 1661
2 Detectable result and exceeds the calibrated range of assay 0 1661
. Missing 944 2605

LBX4AL - Butyraldehyde (ng/mL)

Variable Name:
LBX4AL
SAS Label:
Butyraldehyde (ng/mL)
English Text:
Butyraldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.221 to 16.9 Range of Values 1952 1952
. Missing 653 2605

LBD4ALC - Butyraldehyde Comment Code

Variable Name:
LBD4ALC
SAS Label:
Butyraldehyde Comment Code
English Text:
Butyraldehyde 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 1600 1600
1 Below lower detection limit 352 1952
2 Detectable result and exceeds the calibrated range of assay 0 1952
. Missing 653 2605

LBXCRAL - Crotonaldehyde (ng/mL)

Variable Name:
LBXCRAL
SAS Label:
Crotonaldehyde (ng/mL)
English Text:
Crotonaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.104 to 2.44 Range of Values 1948 1948
. Missing 657 2605

LBDCRLC - Crotonaldehyde Comment Code

Variable Name:
LBDCRLC
SAS Label:
Crotonaldehyde Comment Code
English Text:
Crotonaldehyde 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 711 711
1 Below lower detection limit 1237 1948
2 Detectable result and exceeds the calibrated range of assay 0 1948
. Missing 657 2605

LBX10AL - Decanaldehyde (ng/mL)

Variable Name:
LBX10AL
SAS Label:
Decanaldehyde (ng/mL)
English Text:
Decanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
2.76 to 13.3 Range of Values 1604 1604
. Missing 1001 2605

LBD10ALC - Decanaldehyde Comment Code

Variable Name:
LBD10ALC
SAS Label:
Decanaldehyde Comment Code
English Text:
Decanaldehyde 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 12 12
1 Below lower detection limit 1592 1604
2 Detectable result and exceeds the calibrated range of assay 0 1604
. Missing 1001 2605

LBX7AL - Heptanaldehyde (ng/mL)

Variable Name:
LBX7AL
SAS Label:
Heptanaldehyde (ng/mL)
English Text:
Heptanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.221 to 3.83 Range of Values 1725 1725
. Missing 880 2605

LBD7ALC - Heptanaldehyde Comment Code

Variable Name:
LBD7ALC
SAS Label:
Heptanaldehyde Comment Code
English Text:
Heptanaldehyde 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 1586 1586
1 Below lower detection limit 139 1725
2 Detectable result and exceeds the calibrated range of assay 0 1725
. Missing 880 2605

LBX6AL - Hexanaldehyde (ng/mL)

Variable Name:
LBX6AL
SAS Label:
Hexanaldehyde (ng/mL)
English Text:
Hexanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.49 to 62.1 Range of Values 1751 1751
. Missing 854 2605

LBD6ALC - Hexanaldehyde Comment Code

Variable Name:
LBD6ALC
SAS Label:
Hexanaldehyde Comment Code
English Text:
Hexanaldehyde 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 1708 1708
1 Below lower detection limit 43 1751
2 Detectable result and exceeds the calibrated range of assay 0 1751
. Missing 854 2605

LBXI5AL - Isopentanaldehyde (ng/mL)

Variable Name:
LBXI5AL
SAS Label:
Isopentanaldehyde (ng/mL)
English Text:
Isopentanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.13 to 4.57 Range of Values 2013 2013
. Missing 592 2605

LBDI5ALC - Isopentanaldehyde Comment Code

Variable Name:
LBDI5ALC
SAS Label:
Isopentanaldehyde Comment Code
English Text:
Isopentanaldehyde 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 1998 1998
1 Below lower detection limit 15 2013
2 Detectable result and exceeds the calibrated range of assay 0 2013
. Missing 592 2605

LBX9AL - Nonanaldehyde (ng/mL)

Variable Name:
LBX9AL
SAS Label:
Nonanaldehyde (ng/mL)
English Text:
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.86 to 39.8 Range of Values 1737 1737
. Missing 868 2605

LBD9ALC - Nonanaldehyde Comment Code

Variable Name:
LBD9ALC
SAS Label:
Nonanaldehyde Comment Code
English Text:
Nonanaldehyde 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 674 674
1 Below lower detection limit 1063 1737
2 Detectable result and exceeds the calibrated range of assay 0 1737
. Missing 868 2605

LBX8AL - Octanaldehyde (ng/mL)

Variable Name:
LBX8AL
SAS Label:
Octanaldehyde (ng/mL)
English Text:
Octanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.467 to 3.61 Range of Values 1652 1652
. Missing 953 2605

LBD8ALC - Octanaldehyde Comment Code

Variable Name:
LBD8ALC
SAS Label:
Octanaldehyde Comment Code
English Text:
Octanaldehyde 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 255 255
1 Below lower detection limit 1397 1652
2 Detectable result and exceeds the calibrated range of assay 0 1652
. Missing 953 2605

LBXTLAL - o-Tolualdehyde (ng/mL)

Variable Name:
LBXTLAL
SAS Label:
o-Tolualdehyde (ng/mL)
English Text:
o-Tolualdehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.1 to 2.38 Range of Values 1772 1772
. Missing 833 2605

LBDTLALC - o-Tolualdehyde Comment Code

Variable Name:
LBDTLALC
SAS Label:
o-Tolualdehyde Comment Code
English Text:
o-Tolualdehyde 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 69 69
1 Below lower detection limit 1703 1772
2 Detectable result and exceeds the calibrated range of assay 0 1772
. Missing 833 2605

LBX5AL - Pentanaldehyde (ng/mL)

Variable Name:
LBX5AL
SAS Label:
Pentanaldehyde (ng/mL)
English Text:
Pentanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.223 to 6.61 Range of Values 1970 1970
. Missing 635 2605

LBD5ALC - Pentanaldehyde Comment Code

Variable Name:
LBD5ALC
SAS Label:
Pentanaldehyde Comment Code
English Text:
Pentanaldehyde 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 704 704
1 Below lower detection limit 1266 1970
2 Detectable result and exceeds the calibrated range of assay 0 1970
. Missing 635 2605

LBX3AL - Propanaldehyde (ng/mL)

Variable Name:
LBX3AL
SAS Label:
Propanaldehyde (ng/mL)
English Text:
Propanaldehyde (ng/mL)
Target:
Both males and females 18 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.82 to 17.7 Range of Values 1920 1920
. Missing 685 2605

LBD3ALC - Propanaldehyde Comment Code

Variable Name:
LBD3ALC
SAS Label:
Propanaldehyde Comment Code
English Text:
Propanaldehyde 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 1744 1744
1 Below lower detection limit 176 1920
2 Detectable result and exceeds the calibrated range of assay 0 1920
. Missing 685 2605