Urine glyphosate exposure and serum sex hormone disruption within the 2013–2014 National Health and Nutrition Examination survey (NHANES)

Glyphosate-based herbicides (GBHs) are one of the most commonly used herbicides worldwide. Numerous in vitro and in vivo model system studies have demonstrated endocrine-disrupting chemical (EDC) properties associated with glyphosate/GBH exposure. The present hypothesis-testing study evaluated the potential inverse dose-dependent relationship between increasing urinary glyphosate and decreasing concentrations of blood sex hormones. Demographic and newly available lab test data from the 2013-2014 National Health and Nutrition Examination Survey (NHANES) were analyzed with survey regression modeling (adjusted for age, gender, race, and country of birth) in Statistical Analysis System (SAS) software. A total of 225, 615, 858 weighted-persons (sample n = 2130 persons) were examined for concentrations of urinary glyphosate and serum sex hormones (including: total testosterone, total estradiol, and sex hormone binding globulin (SHBG)) among males and females, 6 years-old or older. This study revealed about 82% of the population of the United States examined had detectable urinary concentrations of glyphosate. A significant inverse correlation between concentrations of glyphosate and total estradiol and a trend towards an inverse correlation between concentrations of glyphosate and total testosterone were observed. Concentrations of SHBG and glyphosate did not correlate. Ratios of total testosterone:SHBG and total estradiol:SHBG (estimating the fraction of active sex hormones in the blood) were significantly inversely correlated with urinary concentrations of glyphosate. This epidemiological study associates widespread and ongoing glyphosate/GBH exposures with human endocrine-disruptions. Future studies should examine these phenomena in other databases and other endocrine-related disorders.