15
Aug
Pesticide Biomarkers in Urine Find High Pesticide Exposure in Region of Ecuador Cultivating Cut Flowers for Export
(Beyond Pesticides, August 15, 2025) In analyzing the data present in an article in Data in Brief, concerning levels of pesticide biomarkers are present in the urine of adolescents and young adults that are linked to numerous health implications. The biomonitoring data, collected at two time points from participants in a longitudinal cohort study in the agricultural county of Pedro Moncayo, Ecuador, encompasses a total of 23 compounds used as herbicides, insecticides, and fungicides and their associated metabolites (breakdown products), which include organophosphates, pyrethroids, and neonicotinoids. The results highlight the disproportionate risks to a Latin American population that occur as a result of living in areas with heavy chemical-intensive agriculture.
“This article presents urinary pesticide metabolite concentrations for 665 participants in the ‘Study of Secondary Exposure to Pesticides among Children, Adolescents, and Adults’ (ESPINA), which were collected during two follow-up assessments,†the authors describe. The first sampling period from July to October 2016, referred to as Follow-up Year [FUY]-8b, includes 529 of the participants, while the second sampling period from July to September 2022 (FUY-14a) includes 505 of the participants. All participants are within the agricultural community of Pedro Moncayo.
As the authors note, “The ESPINA study aimed to include a balanced mix of children who did and did not cohabitate with a floricultural or agricultural worker.†This highlights both the exposure routes from the surrounding environment as well as indirect occupational exposure from another occupant in the house through contaminated clothing and items.
The use of biomonitoring data in relation to pesticide exposure, particularly in agricultural communities, shows real-world exposure as well as the heightened health risks to farmworkers, their families, and individuals living near agricultural land. “Unlike self-reported data or environmental sampling, biomonitoring provides objective, quantitative evidence of exposure, capturing multiple pathways such as inhalation, ingestion, and dermal absorption,†the researchers state.
These pathways offer insight into acute, chronic, and low-dose exposure that studies connect to long-term adverse health effects. With this study focused on Latin America, where agricultural work is prevalent and supports many individuals and families, biomonitoring data is valuable in understanding the impacts of chemical exposure.
The ESPINA cohort was initially established in 2008 with a goal “to investigate the impacts of pesticide exposure on development from childhood to adulthood in individuals living within the agricultural community of Pedro Moncayo, Pichincha, Ecuador.†With cut flowers as one of the primary exports from Ecuador, and an emphasis in Pedro Moncayo on rose and flower cultivation, data from this region incorporates exposure to a variety of pesticides from multiple chemical classes.
“Of the 505 participants examined in 2022 (FUY-14), 212 were returning participants who had been examined in 2016, while the remaining 293 were newly recruited at that timepoint,†the researchers note. They continue, “Across both 2016 and 2022, a total of 665 distinct individuals contributed to the dataset, with 212 individuals contributing data at both timepoints and the remaining participants providing data at only one of the two examination periods.â€
To assess the levels of biomarkers for specific pesticide metabolites, urine samples were collected from participants in 2016 and 2022 upon awakening, considered a first morning void, and analyzed through chromatography and spectrometry techniques. (See additional Beyond Pesticides coverage of biomonitoring studies using urine samples in agricultural communities here, in newborns and children here and here, and from nonoccupational exposure here.)
For the 2016 examination (FUY-8b), 19 metabolites are screened for that correlate with 21 total compounds. The second examination in 2022 (FUY-14a) screens for 14 metabolites that correlate with 20 total compounds, overlapping with 18 compounds from the first sampling period.
In FUY-8b, biomarkers included are associated with the following pesticides:
- Organophosphates (parathion, chlorpyrifos, diazinon, malathion)
- Pyrethroids (cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, permethrin, tralomethrin, cyfluthrin, flumethrin)
- Neonicotinoid Insecticides (imidacloprid, acetamiprid, clothianidin, thiamethoxam, thiacloprid)
- Herbicides (glyphosate, 2,4-D)
- Fungicides (ethylene bis-dithiocarbamates (EBDC) such as maneb and mancozeb)
- Insect Repellent (N,N-diethyl-meta-toluamide (DEET))
The FUY-14a screening includes all of the above except for thiacloprid, glyphosate, and EBDC and has the addition of two systemic insecticides, sulfoxaflor (a sulfoxamine) and flupyradifurone (a butenolide).
The results show the FUY-14a participants have higher urinary pesticide biomarker concentrations for seven biomarkers that are associated with parathion, chlorpyrifos, cyhalothrin, cypermethrin, deltamethrin, fenpropathrin, permethrin, tralomethrin, cyfluthrin, imidacloprid, acetamiprid, clothianidin, and thiamethoxam but lower for 2,4-D, malathion, and DEET in comparison to the concentrations from the earlier FUY-8b screening. Â
Metabolite concentrations with detection rates of 30% and above are noted for 11 out of 19 metabolites measured in 2016 and 12 out of 16 metabolites measured in 2022. The metabolites at the lower detection rates correlate with only seven of the above-listed parent chemicals in the 2016 screening and four from the 2022 screening. In both sampling periods, two organophosphate pesticide metabolites, which are associated with chlorpyrifos and parathion, have a 100% detection rate. These results highlight the widespread exposure to pesticides that the individuals living and working in agricultural communities experience.
For all of the compounds that are detected above 30%, the Gateway on Pesticide Hazards and Safe Pest Management links them to a multitude of health and environmental implications including cancer, endocrine disruption, reproductive effects, neurotoxicity, kidney/liver damage, birth/developmental effects, and toxicity to birds, bees, and aquatic organisms, among others.Â
As the authors of the current study point out: “One major limitation of measuring pesticide metabolites in urine using mass spectrometry is the short half-life of metabolites, which leads to a narrow window of exposure. Since pesticides are often rapidly metabolized and excreted, a single urine sample may not accurately reflect long-term exposure.†Additional biomonitoring studies for pesticide residues analyze breast milk, sperm, hair, nails, and blood.
In a recent study comparing pesticide concentrations in conventional and organic farmers, hair and nails are used for biological samples, which reflect cumulative exposure, unlike blood or urine, which only account for recent exposure. As the study authors point out, “Hair sequesters trace elements over weeks, while nails, due to their slower growth rate, reflect exposure over several months.†(See Daily News coverage here.) Additional sampling of the hair of over 200 French children finds 69 biomarkers of pollutants and pesticides—12 of which are banned—that highlight heightened risks of early childhood exposure in combination with prenatal exposure from their mothers. (See additional analysis of the study here.)
Biomonitoring studies not only inform disproportionate risks and the widespread pesticide contamination that contributes to body burden, but they also offer insight into how organic systems can eliminate direct and indirect exposure to these toxicants and reduce the levels of pesticide residues in the body even in short amounts of time.
A 2024 literature review, published in the Journal of Agricultural and Food Chemistry, explores levels of pesticide residues found in samples of human urine with environmental exposure and dietary intake and confirms prior findings about the benefits of an organic diet. Similar to past findings, lower concentrations of chemicals are detected in the urine of participants who report eating an organic diet. (See Daily News here.)
Another study in 2025, from a randomized clinical trial published in Nutrire, finds that adopting a fully organic diet can reduce pesticide levels in urine within just two weeks by an average of 98.6% and facilitates faster DNA damage repair relative to a diet of food grown with chemical-intensive practices. The authors explain that their finding “is likely due to two main factors: the presence of compounds characteristic of [an organic] diet, which may have high levels of antioxidants that can protect DNA and also induce DNA repair [], and the absence or decrease in the incidence of pesticides in this type of diet, which are recognized for their genotoxic effects and have the ability to affect the genetic repair system of organisms [].†(See Daily News here.)
Learn more about the health effects of pesticide exposure in the Pesticide-Induced Diseases Database, as well as the health and environmental benefits of organic agriculture and land management here and here.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Parajuli, R. et al. (2025) Urinary pesticide biomarkers from adolescence to young adulthood in an agricultural setting in Ecuador: Study of secondary exposure to pesticides among children, adolescents, and adults (ESPINA) 2016 and 2022 examination data, Data in Brief. Available at: https://www.sciencedirect.com/science/article/pii/S2352340925006067.
