Measurement of Agricultural and Dietary Glyphosate Exposure Among Pregnant Women

The purpose of this research is to understand whether and how pregnant women may be exposed to glyphosate, the active ingredient in a common herbicide. The researchers aim to assess glyphosate exposure among pregnant women in Idaho, and to attribute that exposure to agricultural and dietary sources. Pregnant women who live either near or far from glyphosate-treated fields will be recruited for study inclusion, and exposure will be assessed via urinary biomonitoring on a weekly basis throughout pregnancy. Each participant will also take part in a two-week dietary intervention, during which they will receive one week of organic food and one week of conventional food, in a crossover design. Urinary biomonitoring will occur on a daily basis during the dietary intervention phase. The researchers hypothesize that women who live near agricultural fields treated with glyphosate will have higher exposures than those who live in non-agricultural regions, and that consumption of an organic diet will reduce exposures in both groups. All study components will be completed with no face-to-face interaction to eliminate all coronavirus (COVID-19) related risks.

Study Overview

• Status: Completed
• Conditions: Exposure to Herbicides
• Intervention / Treatment: Other: Organic Diet; Other: Conventional Diet

Detailed Description

This study focuses on human exposure to glyphosate, the single most commonly applied agricultural chemical in the world. Glyphosate is an herbicide, and is most commonly known as the active ingredient in "Round Up". Glyphosate has been declared a probable human carcinogen by the International Agency for Research on Cancer and multiple toxicological studies have further suggested potential neurological and developmental effects of glyphosate exposure at environmentally-relevant levels. However, despite its extensive use, frequent presence in food and environmental media, and potential toxicity, current exposure levels in human populations are not well documented. This study aims to assess glyphosate exposure among a cohort of pregnant women and to quantify the relative contribution of agricultural and dietary sources of this exposure. A cohort of 40 pregnant women will be recruited from urban areas >10 miles from the nearest glyphosate-treated field and agricultural areas <1 mile from the nearest glyphosate-treated field. Weekly urine samples collected from these women throughout their pregnancies will be used to analyze glyphosate exposure. These same 40 participants will also take part in a two week-long randomized cross-over design dietary intervention, during which participants will receive one week of exclusively organic food (grown without the use of synthetic pesticides, including glyphosate) and one week of exclusively conventional food, in random order. During the intervention, the researchers will collect daily spot urine samples from each participant to analyze glyphosate exposure related to diet. The researchers hypothesize that during the time of year when glyphosate is actively applied, women living near glyphosate-treated fields will have higher exposures than those living further away. They also hypothesize that glyphosate exposure will be reduced among participants during randomization to the organic diet, but that this decrease will be larger among urban women than among those living near glyphosate-treated fields. The researchers have taken extra precautions to eliminate all COVID-specific risks. There will be no face-to-face contact between research staff and study participants throughout the entire study. Interactions between researchers and study participants will take place through videos, emails, texts, and/or phone calls. All urine samples will be left for researchers to pick up at a predetermined location and time, and all groceries will be delivered to participants' home and left at their front door.

• Study Type: Interventional
• Enrollment (Actual): 40
• Phase: Not Applicable

Contacts and Locations

Study Locations

• United States
  • Idaho
    • Boise, Idaho, United States, 83725
      • Boise State University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 35 years (Adult)
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Be in the first trimester of pregnancy
• No diagnosis of gestational diabetes or other high risk pregnancy factors
• Consume an exclusively conventional diet with no intentions to switch to an organic diet
• Agree to refrain from applying residential glyphosate (Round Up) during the study
• Either live more than 10 miles or less than 1 mile from a glyphosate treated field

Exclusion Criteria:

- Occupational exposure to glyphosate, or live in a household with an individual with occupational glyphosate exposure

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: None (Open Label)

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Organic Diet, Then Conventional Diet: These participants first received an organic diet for one week. During that week, daily first morning void urine samples were collected. After a washout period of one day, these participants then received a conventional (non-organic) diet for one week. During that week, daily first morning void urine samples were collected. For each week, participants ordered all food they anticipated eating that week (up to $150) from a unique account with a local grocery store in accordance with either the organic diet or conventional diet. Study staff verified all food items corresponded with the dietary intervention that week, and then ordered the groceries to be delivered to the participant's home, when possible. For participants living in areas in which delivery was not available (generally rural areas), study staff picked up the food at the grocery store and delivered it to the participant's home.	Other: Organic Diet; Participants receive one week of organic food. Organic food is certified through the USDA's National Organic Program as produced without the use of synthetic pesticides, including glyphosate.; Other: Conventional Diet; Participants receive one week of conventionally grown (non-organic) food.
Experimental: Conventional Diet, Then Organic Diet; These participants first received a conventional (non-organic) diet for one week. During that week, daily first morning void urine samples were collected. After a washout period of one day, these participants then received an organic diet for one week. During that week, daily first morning void urine samples were collected. For each week, participants ordered all food they anticipated eating that week (up to $150) from a unique account with a local grocery store in accordance with either the organic diet or conventional diet. Study staff verified all food items corresponded with the dietary intervention that week, and then ordered the groceries to be delivered to the participant's home, when possible. For participants living in areas in which delivery was not available (generally rural areas), study staff picked up the food at the grocery store and delivered it to the participant's home.	Other: Organic Diet; Participants receive one week of organic food. Organic food is certified through the USDA's National Organic Program as produced without the use of synthetic pesticides, including glyphosate.; Other: Conventional Diet; Participants receive one week of conventionally grown (non-organic) food.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Specific Gravity-adjusted Urinary Glyphosate Concentrations During Conventional and Organic Diet	We collected 531 daily first morning void urine samples. We aliquoted 0.6 mL of each participant's seven daily urine samples to form a composite sample intended to represent each participant's mean glyphosate exposure during each week of the dietary intervention For all 39 participants there was one weekly composite urine sample from the conventional diet period and one weekly composite urine sample from the organic diet period. These 78 composite urine samples were analyzed for glyphosate concentrations and adjusted for urine specific gravity.	One week conventional diet and one week organic diet

Collaborators and Investigators

• Sponsor: Boise State University
• Collaborators: National Institute of Environmental Health Sciences (NIEHS)
• Investigators: Principal Investigator: Cynthia Curl, PhD, Boise State University

Study record dates

Study Major Dates

• Study Start (Actual): February 23, 2021
• Primary Completion (Actual): June 30, 2021
• Study Completion (Actual): December 28, 2021

Study Registration Dates

• First Submitted: November 5, 2019
• First Submitted That Met QC Criteria: November 5, 2019
• First Posted (Actual): November 7, 2019

Study Record Updates

• Last Update Posted (Actual): April 14, 2023
• Last Update Submitted That Met QC Criteria: April 13, 2023
• Last Verified: April 1, 2023

More Information

Terms related to this study

• Keywords: Pregnancy; Dietary Intervention; Glyphosate; Herbicide; Agricultural Communities; Organic food
• Other Study ID Numbers: K01ES028745 (U.S. NIH Grant/Contract)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No