Table of Contents

Locator Record

Title: Environmental Phenols and Parabens (EPH_G )
Contact Number: 1-866-441-NCHS
Years of Content: 2011 - 2012
First Published: November, 2013
Revised: NA
Access Constraints: None
Use Constraints: None
Geographic Coverage: National
Subject:Environmental Phenols and Parabens
Record Source: NHANES 2011 - 2012
Survey Methodology: NHANES 2011 - 2012 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

Biomonitoring of environmental phenols is used to determine their prevalence in humans and the relevance of human exposure in public health. The routes of human exposure to these phenolic compounds are industrial pollution, pesticide use, food consumption, or use of personal care products. Specifically, bisphenol A (BPA) is used in the manufacture of polycarbonate plastics and epoxy resins, which are used in baby bottles, as protective coatings on food containers, and as composites and sealants in dentistry. Phenols are also used as sunscreen agents for skin protection, and as UV filters in cosmetic products and plastics to improve stability (e.g., benzophenone-3 [BP-3]), or used as bactericides (e.g., triclosan) in soap and other personal care products.  Parabens, a group of alkyl (e.g., methyl, ethyl, propyl, butyl) esters of p-hydroxybenzoic acid, are widely used as antimicrobial preservatives in personal care products; parabens can also be used in pharmaceuticals, and in food and beverage processing.

Eligible Sample

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

Description of Laboratory Methodology

We have developed a sensitive method for measuring BPA, BP-3, triclosan, and four parabens (Ye et al., 2005, 2006). The method uses on-line solid phase extraction (SPE) coupled to HPLC and tandem mass spectrometry (HPLC-MS/MS). With the use of isotopically labeled internal standards, the detection limits in 100 μL of urine are 0.1-2.3 nanograms per milliliter (ng/mL), sufficient for measuring urinary levels of phenols in non-occupationally exposed subjects.

Laboratory Quality Assurance and Monitoring

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). 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 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 2.0% of all specimens.

NCHS developed and distributed a quality control protocol for all the contract laboratories which outlined the Westgard rules used 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 Division of Environmental Health Laboratory Sciences’ quality control and quality assurance performance criteria for accuracy and precision (similar to specifications outlined by Westgard (1981).

Analytic Notes

Refer to the 2011-2012 Laboratory Data Overview for general information on NHANES laboratory data.

Subsample weights

Measures of urinary environmental phenols and parabens were measured in a one third subsample of persons 6 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.

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 data files using the unique survey participant identifier 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 named URD___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.

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

The lower limit of detection (in ug/L)  for the environmental phenols and parabensis: 

Analyte Item ID LLOD
Urinary Bisphenol A URXBPH 0.4
Urinary 2,4,4’-Trichloro-2’-hydroxyphenyl ether (Triclosan) URXTRS 2.3
Urinary 2-Hydroxy-4-metoxybenzophenone (Benzophenone-3) URXBP3 0.4
Urinary Propyl paraben URXPPB 0.2
Urinary Butyl paraben URXBUP 0.2
Urinary Ethyl paraben URXEPB 1
Urinary Methyl paraben URXMPB 1

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
0.0000 to 654828.2015 Range of Values 0 0
0 0 2594 2594
. Missing 0 2594

URXUCR - Urinary creatinine

Variable Name:
URXUCR
SAS Label:
Urinary creatinine
English Text:
Urinary creatinine
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
4 to 800 Range of Values 2525 2525
. Missing 69 2594

URXBP3 - Urinary Benzophenone-3 (ng/mL)

Variable Name:
URXBP3
SAS Label:
Urinary Benzophenone-3 (ng/mL)
English Text:
Urinary 2-Hydroxy-4-metoxybenzophenone (Benzophenone-3)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.28 to 66600 Range of Values 2489 2489
. Missing 105 2594

URDBP3LC - Urinary Benzophenone-3 comment

Variable Name:
URDBP3LC
SAS Label:
Urinary Benzophenone-3 comment
English Text:
Urinary 2-Hydroxy-4-metoxybenzophenone (Benzophenone-3) 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 2439 2439
1 Below lower detection limit 50 2489
. Missing 105 2594

URXBPH - Urinary Bisphenol A (ng/mL)

Variable Name:
URXBPH
SAS Label:
Urinary Bisphenol A (ng/mL)
English Text:
Urinary Bisphenol A (ng/mL)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.28 to 179 Range of Values 2489 2489
. Missing 105 2594

URDBPHLC - Urinary Bisphenol A comment code

Variable Name:
URDBPHLC
SAS Label:
Urinary Bisphenol A comment code
English Text:
Urinary Bisphenol A 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 2233 2233
1 Below lower detection limit 256 2489
. Missing 105 2594

URXTRS - Urinary Triclosan (ng/mL)

Variable Name:
URXTRS
SAS Label:
Urinary Triclosan (ng/mL)
English Text:
Urinary 2,4,4’-Trichloro-2’-hydroxyphenyl ether (Triclosan)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
1.63 to 3830 Range of Values 2489 2489
. Missing 105 2594

URDTRSLC - Urinary Triclosan comment

Variable Name:
URDTRSLC
SAS Label:
Urinary Triclosan comment
English Text:
Urinary 2,4,4’-Trichloro-2’-hydroxyphenyl ether (Triclosan) 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 1790 1790
1 Below lower detection limit 699 2489
. Missing 105 2594

URXBUP - Butyl paraben (ng/ml)

Variable Name:
URXBUP
SAS Label:
Butyl paraben (ng/ml)
English Text:
Butyl paraben (ng/ml)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.14 to 308 Range of Values 2489 2489
. Missing 105 2594

URDBUPLC - Butyl paraben comment

Variable Name:
URDBUPLC
SAS Label:
Butyl paraben comment
English Text:
Butyl paraben 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 662 662
1 Below lower detection limit 1827 2489
. Missing 105 2594

URXEPB - Ethyl paraben (ng/ml)

Variable Name:
URXEPB
SAS Label:
Ethyl paraben (ng/ml)
English Text:
Ethyl paraben (ng/ml)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.71 to 1140 Range of Values 2489 2489
. Missing 105 2594

URDEPBLC - Ethyl paraben comment

Variable Name:
URDEPBLC
SAS Label:
Ethyl paraben comment
English Text:
Ethyl paraben comment
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 1098 1098
1 Below lower detection limit 1391 2489
. Missing 105 2594

URXMPB - Methyl paraben (ng/ml)

Variable Name:
URXMPB
SAS Label:
Methyl paraben (ng/ml)
English Text:
Methyl paraben (ng/ml)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.71 to 13500 Range of Values 2489 2489
. Missing 105 2594

URDMPBLC - Methyl paraben comment

Variable Name:
URDMPBLC
SAS Label:
Methyl paraben comment
English Text:
Methyl paraben comment
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 2461 2461
1 Below lower detection limit 28 2489
. Missing 105 2594

URXPPB - Propyl paraben (ng/ml)

Variable Name:
URXPPB
SAS Label:
Propyl paraben (ng/ml)
English Text:
Propyl paraben (ng/ml)
Target:
Both males and females 6 YEARS - 150 YEARS
Code or Value Value Description Count Cumulative Skip to Item
0.14 to 3320 Range of Values 2489 2489
. Missing 105 2594

URDPPBLC - Propyl paraben comment

Variable Name:
URDPPBLC
SAS Label:
Propyl paraben comment
English Text:
Propyl paraben 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 2344 2344
1 Below lower detection limit 145 2489
. Missing 105 2594