Glyphosate is the most widely used herbicide in the United States in the agricultural sector and the second most used in the home and garden market sector (US EPA 2017). Its use has increased more than 200-fold since 1974 when Monsanto commercialized it under the trade name Roundup (Benbrook, 2016). In 2015, the International Agency for Research on Cancer determined that glyphosate is a “probable human carcinogen” (IARC, 2015). However, the European Food Safety Authority and the Joint Food and Agriculture Organization (FAO)/World Health Organization (WHO) Meeting on Pesticide Residues (EFSA 2015, FAO/WHO 2015) determined that glyphosate is unlikely to be a carcinogen. The US EPA concluded that “available data and weight-of-evidence clearly do not support the descriptors “carcinogenic to humans,” “likely to be carcinogenic to humans,” or “inadequate information to assess carcinogenic potential” (US EPA 2017a). Controversy and concern that the rising use of glyphosate may have adverse human-health effects exist (Myers et. al., 2016). Yet, the extent of human exposure to glyphosate in the U.S. population is largely unknown. Data to better understand exposure to glyphosate are needed to increase our knowledge of its potential effects on health.
A one-third subsample of participants aged 6 years and older, who gave consent for their samples to be used in future research and had stored urine samples from 2013-2014, were eligible.
The method uses 200 microliters of urine and is based on 2D-on-line ion chromatography coupled with tandem mass spectrometry (IC- MS/MS) and isotope dilution quantification (Schutze et. al., 2021).
The analytical measurements were conducted following strict quality control/quality assurance CLIA guidelines. Along with the study samples, each analytical run included high- and low-concentration quality control materials (QCMs) and reagent blanks to assure the accuracy and reliability of the data. The concentrations of the high-concentration QCMs and the low-concentration QCMs, averaged to obtain one measurement of high-concentration QCM and low-concentration QCM for each run, were evaluated using standard statistical probability rules (Caudill et al. 2008).
Data were received after all analyses were complete. The data were not edited.
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.
Special Subsample Weights
Special subsample 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 (WTSSCH2Y).
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.
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 limit was constant for all of the analytes in the data set. Two
variables are provided for each of these analytes. The variable name ending in
“L” (ex., SSGLYPL) 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. The
other variable (ex., SSGLYP) provides the analytic result for that analyte. For
analytes with analytic results below the limit of detection (ex., SSGLYPL=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/√2). The lower
limit of detection (LLOD, in ng/mL) for GLYP:
| Variable Name | Analyte name | LLOD (ng/mL) |
| SSGLYP | Glyphosate | 0.2 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 19943.069763 to 604985.17222 | Range of Values | 2316 | 2316 | |
| 0 | No lab specimen | 0 | 2316 | |
| . | Missing | 0 | 2316 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0.141 to 8.13 | Range of Values | 2310 | 2310 | |
| . | Missing | 6 | 2316 |
| Code or Value | Value Description | Count | Cumulative | Skip to Item |
|---|---|---|---|---|
| 0 | At or above the detection limit | 1885 | 1885 | |
| 1 | Below lower detection limit | 425 | 2310 | |
| . | Missing | 6 | 2316 |