Table of Contents

Locator Record

Title: Urine Heavy Metals (UHM_F )
Contact Number: 1-866-441-NCHS
Years of Content: 2009 - 2010
First Published: September, 2011
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Heavy metals, Multi-analyte profile
Record Source: NHANES 2009 - 2010
Survey Methodology: NHANES 2009 - 2010 is a stratified multistage probability sample of the civilian non-institutionalized population of the U.S.
Medium: NHANES Web site; SAS transport files

Component Description

Trace metals have been associated with adverse health effects in occupational studies or laboratory studies, but have not been monitored in general population groups.

This method is used to achieve rapid and accurate quantifications of multiple elements of toxicological and nutritional interest. The method is sensitive and rapid enough to screen urine specimens from subjects suspected to be exposed to a number of important toxic elements, or to evaluate environmental or other nonoccupationally exposure to these same elements.

Eligible Sample

Participants aged 6 years and older, who met the subsample requirements, were eligible.

Description of Laboratory Methodology

Urine specimens are processed, stored, and shipped to the Division of Environmental Health Laboratory 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). Read the General Documentation on Laboratory Data file for detailed data processing and editing protocols.

Inductively coupled plasma-mass spectrometry (ICP-MS) is a multi-element analytical technique (Date AR, et al., 1989). Liquid samples are introduced into the ICP through a nebulizer and spray chamber carried by a flowing argon stream. By coupling radio-frequency power into flowing argon, plasma is created in which the predominant species are positive argon ions and electrons. The sample passes through a region of the plasma that has a temperature of 6000–8000 ºK. The thermal energy atomizes the sample and then ionizes the atoms. The ions, along with the argon, enter the mass spectrometer through an interface that separates the ICP from the mass spectrometer, which is operating at an atmospheric pressure of 10–5 torr. The mass spectrometer permits ions at each mass to be detected in rapid sequence, allowing individual isotopes of an element to be determined. Electrical signals resulting from the detection of the ions are processed into digital information that is used to indicate first the intensity of the ions and then the concentration of the element. The ICP-MS method is used to measure the following 12 elements in urine: beryllium (Be), cobalt (Co), molybdenum (Mo), cadmium (Cd), antimony (Sb), cesium (Cs), barium (Ba), tungsten (W), platinum (Pt), thallium (TI), lead (Pb), and uranium (U). This method is based on the method by (Mulligan  KJ, et al. 1990)  Urine samples are diluted 1+9 with 2% (v/v), double-distilled, concentrated nitric acid containing both iridium (Ir) and rhodium (Rh) for multi-internal standardization. This procedure can be used for all 12 elements or for subsets of the 12 elements.

There were no changes (from the previous 2 years of NHANES) to equipment, lab methods or lab site.

Detailed instructions on specimen collection and processing can be found in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM).

Data Processing and Editing

Read the General Documentation on Laboratory Data file for detailed data processing and editing protocols.The analytical methods are described in the Description of Laboratory Methodology section above.

Laboratory Quality Assurance and Monitoring

The NHANES quality control and quality assurance protocols (QA/QC) meet the 1988 Clinical Laboratory Improvement Act mandates. Detailed QA/QC instructions are discussed in the NHANES Laboratory/Medical Technologists Procedures Manual (LPM) . Read the General Documentation on Laboratory Data file for detailed QA/QC protocols.

Analytic Notes

NHANES Survey Design:

The analysis of NHANES laboratory data must be conducted with the key survey design and basic demographic variables. The Demographic file contains: Status Variables providing core information on the survey participant including examination status, Recoded Demographic Variables including age, gender, race etc., and Interview and Examination Sample Weight Variables and Survey Design Variables. The Questionnaire Data Files contain socio-economic data, health indicators, and other related information collected during household interviews. The Phlebotomy Examination file includes auxiliary information on duration of fasting, the time of day of the venipuncture, and the conditions precluding venipuncture. The Demographic, Questionnaire and Phlebotomy Examination files may be linked to the laboratory data file using the unique survey participant identifier SEQN.
Subsample weights

Subsample weights

Urinary heavy metals were measured in a one third subsample of persons 6 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 laboratory data must be conducted with the key survey design and basic demographic variables. The NHANES 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 2007-2008 data files using the unique survey participant identifier SEQN.

Detection Limits

The detection limits were constant for all of the heavy metals in the data set.

Lower detection limits for the heavy metals in the data set.:
Urinary Barium= 0.12 µg/L
Urinary Beryllium= 0.072 µg/L
Urinary Cadmium= 0.042 µg/L
Urinary Cobalt= 0.041 µg/L
Urinary Cesium= .066 µg/L
Urinary Molybdenum= .92 µg/L
Urinary Lead= 0.10 µg/L
Urinary Platinum= 0.009 µg/L
Urinary Antimonry= 0.032 ug/L
Urinary Thallium= 0.015 ug/L
Urinary Tungsten= 0.021 ug/L
Urinary Uranium= 0.0017 ug/L

The variable named LBD__LC indicates whether the 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. In cases where the result was below the limit of detection, the value for that variable is the detection limit divided by the square root of two.

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 6 YEARS - 150 YEARS

WTSA2YR - Two-year A subsample weights

Variable Name:
WTSA2YR
SAS Label:
Two-year A subsample weights
English Text:
Two-year A subsample weights
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 to 476882.95898 Range of Values 2941 2941
. Missing 0 2941

URXUCR - Creatinine, urine (mg/dL)

Variable Name:
URXUCR
SAS Label:
Creatinine, urine (mg/dL)
English Text:
Creatinine, urine (mg/dL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
6 to 489 Range of Values 2878 2878
. Missing 63 2941

URXUBA - Barium, urine (ug/L)

Variable Name:
URXUBA
SAS Label:
Barium, urine (ug/L)
English Text:
Barium, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.08 to 419 Range of Values 2848 2848
. Missing 93 2941

URDUBALC - Urinary Barium comment code

Variable Name:
URDUBALC
SAS Label:
Urinary Barium comment code
English Text:
Urinary Barium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2836 2836
1 Below lower detection limit 12 2848
. Missing 93 2941

URXUBE - Beryllium, urine (ug/L)

Variable Name:
URXUBE
SAS Label:
Beryllium, urine (ug/L)
English Text:
Beryllium, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.051 0.051 2848 2848
. Missing 93 2941

URDUBELC - Urinary Beryllium comment code

Variable Name:
URDUBELC
SAS Label:
Urinary Beryllium comment code
English Text:
Urinary Beryllium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 0 0
1 Below lower detection limit 2848 2848
. Missing 93 2941

URXUCD - Cadmium, urine (ug/L)

Variable Name:
URXUCD
SAS Label:
Cadmium, urine (ug/L)
English Text:
Cadmium, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.03 to 8.35 Range of Values 2848 2848
. Missing 93 2941

URDUCDLC - Urinary Cadmium comment code

Variable Name:
URDUCDLC
SAS Label:
Urinary Cadmium comment code
English Text:
Urinary Cadmium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2544 2544
1 Below lower detection limit 304 2848
. Missing 93 2941

URXUCO - Cobalt, urine (ug/L)

Variable Name:
URXUCO
SAS Label:
Cobalt, urine (ug/L)
English Text:
Cobalt, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.029 to 37.4 Range of Values 2848 2848
. Missing 93 2941

URDUCOLC - Urinary Cobalt (ug/L) comment code

Variable Name:
URDUCOLC
SAS Label:
Urinary Cobalt (ug/L) comment code
English Text:
Urinary Cobalt (ug/L) comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2830 2830
1 Below lower detection limit 18 2848
. Missing 93 2941

URXUCS - Cesium, urine (ug/L)

Variable Name:
URXUCS
SAS Label:
Cesium, urine (ug/L)
English Text:
Cesium, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.205 to 27.2 Range of Values 2848 2848
. Missing 93 2941

URDUCSLC - Urinary Cesium comment code

Variable Name:
URDUCSLC
SAS Label:
Urinary Cesium comment code
English Text:
Urinary Cesium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2848 2848
1 Below lower detection limit 0 2848
. Missing 93 2941

URXUMO - Molybdenum, urine (ug/L)

Variable Name:
URXUMO
SAS Label:
Molybdenum, urine (ug/L)
English Text:
Molybdenum, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.41 to 649 Range of Values 2848 2848
. Missing 93 2941

URDUMOLC - Urinary Molybdenum comment code

Variable Name:
URDUMOLC
SAS Label:
Urinary Molybdenum comment code
English Text:
Urinary Molybdenum comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2848 2848
1 Below lower detection limit 0 2848
. Missing 93 2941

URXUPB - Lead, urine (ug/L)

Variable Name:
URXUPB
SAS Label:
Lead, urine (ug/L)
English Text:
Lead, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.07 to 49.6 Range of Values 2848 2848
. Missing 93 2941

URDUPBLC - Urinary Lead comment code

Variable Name:
URDUPBLC
SAS Label:
Urinary Lead comment code
English Text:
Urinary Lead comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2768 2768
1 Below lower detection limit 80 2848
. Missing 93 2941

URXUPT - Platinum, urine (ug/L)

Variable Name:
URXUPT
SAS Label:
Platinum, urine (ug/L)
English Text:
Platinum, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.006 to 621 Range of Values 2847 2847
. Missing 94 2941

URDUPTLC - Urinary Platinum comment code

Variable Name:
URDUPTLC
SAS Label:
Urinary Platinum comment code
English Text:
Urinary Platinum comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 332 332
1 Below lower detection limit 2515 2847
. Missing 94 2941

URXUSB - Antimony, urine (ug/L)

Variable Name:
URXUSB
SAS Label:
Antimony, urine (ug/L)
English Text:
Antimony, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.023 to 4.05 Range of Values 2847 2847
. Missing 94 2941

URDUSBLC - Urinary Antimony comment code

Variable Name:
URDUSBLC
SAS Label:
Urinary Antimony comment code
English Text:
Urinary Antimony comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2116 2116
1 Below lower detection limit 731 2847
. Missing 94 2941

URXUTL - Thallium, urine (ug/L)

Variable Name:
URXUTL
SAS Label:
Thallium, urine (ug/L)
English Text:
Thallium, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.011 to 2.35 Range of Values 2848 2848
. Missing 93 2941

URDUTLLC - Urinary Thallium comment code

Variable Name:
URDUTLLC
SAS Label:
Urinary Thallium comment code
English Text:
Urinary Thallium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2833 2833
1 Below lower detection limit 15 2848
. Missing 93 2941

URXUTU - Tungsten, urine (ug/L)

Variable Name:
URXUTU
SAS Label:
Tungsten, urine (ug/L)
English Text:
Tungsten, urine (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.015 to 5.248 Range of Values 2847 2847
. Missing 94 2941

URDUTULC - Urinary Tungsten comment code

Variable Name:
URDUTULC
SAS Label:
Urinary Tungsten comment code
English Text:
Urinary Tungsten comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2558 2558
1 Below lower detection limit 289 2847
. Missing 94 2941

URXUUR - Uranium, urinary (ug/L)

Variable Name:
URXUUR
SAS Label:
Uranium, urinary (ug/L)
English Text:
Uranium, urinary (ug/L)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.0012 to 1.824 Range of Values 2848 2848
. Missing 93 2941

URDUURLC - Urinary Uranium comment code

Variable Name:
URDUURLC
SAS Label:
Urinary Uranium comment code
English Text:
Urinary Uranium comment code
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0 At or above the detection limit 2649 2649
1 Below lower detection limit 199 2848
. Missing 93 2941