Food Contaminants
occupational pesticide exposure decreases semen quality
In plain terms: Does working with pesticides damage sperm quality?
Contested Food Contaminants 🔬 Includes disconfirming
Part of: 🔍 pesticides in food
RefutedContestedStrong support
consensus score 0.00
There is a real signal, strongest for sperm movement and DNA damage rather than count. But much of the apparently large evidence base is the same studies reviewed repeatedly, and the cleanest occupational studies disagree.
📅 Last reviewed: 2026-07-29 ⓘ
Evidence ladder
How far up the ladder this claim has climbed. A high consensus on a low rung means "consistent so far," not "proven in people."
Top evidence so far: Population patterns (Observational)
MechanismIn-vitroAnimalObservationalRCTMeta-analysis
How the studies fall
1 support 1 contradict 0 tested null 21 mixed · 23 sources, 2 independent groups
What the evidence shows
Real but narrower than the literature's volume suggests. The most consistent signal is on sperm motility and DNA fragmentation rather than a uniform decline across all parameters, and a rigorous Navigation Guide review rated motility evidence 'sufficient' while concentration was 'limited'. Two problems keep this contested.
The evidence (23)
| Source | Grade | Stance | Quality | Finding |
|---|---|---|---|---|
| Qi Y et al 2026 · study_type: observational | observational | mixed | low | Narrative review (82 papers, mostly 2020-2025) lists pesticides among several environmental factors (heavy metals, PFAS, phthalates, air pollution) reducing sperm concentration/motility/morphology/DNA stability via oxidative stress and endo |
| Cardoso CA et al 2025 · study_type: animal | animal | mixed | low | EXPERIMENTAL ANIMAL study (20 Wistar rats, neem aqueous-extract natural biopesticide, 5,000-10,000 ppm x8 days): sperm motility and viability declined dose-dependently, with inviable spermatozoa only at the highest dose; authors judge overa |
| Giulioni C et al 2022 · Andrology | observational | mixed | moderate | Systematic review of 64 human studies (environmental AND occupational combined; 51 on semen parameters, 25 on DNA/chromatin) found total sperm count, motility, and morphology most consistently affected, with organochlorines/organophosphates |
| Cofone L et al 2023 · Annali di igiene : medicina preventiva e di comunita | observational | mixed | moderate | Systematic review of 21 biomonitoring studies (environmental/occupational, urine and blood matrices) found overall pollutant burden - bisphenols, phthalates, PCBs, PAHs, metals, AND pesticides together - correlated with decreased motility, |
| Hamed MA et al 2023 · Frontiers in endocrinology | meta-analysis | mixed | moderate | Meta-analysis of 766 men (349 OP-exposed vs 417 controls; exposure route not specified in abstract) found reduced sperm count, concentration, total/progressive motility, and normal morphology in exposed men with no change in FSH/LH/testoste |
| Elmorsy EM et al 2026 · study_type: animal | animal | mixed | low | EXPERIMENTAL ANIMAL study (60 rats, cypermethrin/pyrethroid; specific mg/kg dose not given in abstract): cypermethrin reduced sperm count (5.62x10^6 vs control) and motility (49.3%) while raising abnormal sperm (18.2%) via oxidative stress/ TEMPERED: preclinical (animal/in-vitro) evidence, retained in the ledger but not carrying a human-outcome headline; dosing is typically far above human exposure. |
| El-Demerdash FM et al 2026 · Scientific Reports | animal | mixed | moderate | EXPERIMENTAL ANIMAL study (adult male rats, lambda-cyhalothrin 8 mg/kg and/or thiamethoxam 156 mg/kg orally x21 days): combined pyrethroid+neonicotinoid exposure caused significant declines in sperm quality plus disrupted steroidogenic gene TEMPERED: preclinical (animal/in-vitro) evidence, retained in the ledger but not carrying a human-outcome headline; dosing is typically far above human exposure. |
| Oladosu WO et al 2026 · Indian journal of occupational and environmental medicine | observational | mixed | moderate | Cross-sectional study (Nigeria, 130 men with abnormal semen parameters vs 130 normal controls), seminal-fluid biomarker (GC/MS) - exposure attributed to mixed home/farmland/agricultural-storage routes, not clearly restricted to occupational |
| Istvan M et al 2021 · Human reproduction (Oxford, England) | observational | mixed | moderate | Cross-sectional study of 1737 Swiss conscripts: exposure is MATERNAL occupational pesticide exposure DURING PREGNANCY (job-exposure matrix) - a prenatal-route study of the subject's mother, not the subject's own adult occupational exposure |
| Tielemans E et al 1999 · Fertility and sterility | observational | contradicts | moderate | Case-control study of 899 infertility-clinic male partners (Netherlands), OCCUPATIONAL exposure via job-exposure matrix plus urinary biomarkers (for solvents/metals): workplace PESTICIDE exposure specifically was NOT associated with impaire |
| Bicca DF et al 2025 · study_type: in-vitro | in-vitro | mixed | low | IN-VITRO study (pooled bull sperm incubated 3h with glyphosate 50ug/mL, 2,4-D 0.11ug/mL, and/or atrazine 0.0107ug/mL): single agents and some mixtures reduced progressive motility/velocity and fertilizing capacity, but membrane/acrosome int |
| Rahban R et al 2025 · study_type: observational | observational | mixed | low | Ecological/spatial study (2677 Swiss conscripts, RESIDENTIAL/agricultural-proximity route via land-use proxy, no individual exposure measurement): the persistent LOW semen-quality cluster had more surrounding fodder/field-crop land (52% vs |
| Daoud S et al 2017 · Turkish journal of medical sciences | observational | supports | moderate | Cross-sectional study of 2122 infertile men (Turkey), OCCUPATIONAL exposure via self-report job-title questionnaire (not biomarker): pesticide exposure associated with higher asthenozoospermia (OR 1.6, 95% CI 1.0-2.4) and necrozoospermia (O |
| Stapleton JL et al 2025 · study_type: observational | observational | mixed | low | Pilot cross-sectional study (n=42 healthy young men, general population - route not occupational), urinary AND seminal-plasma OP metabolite (DAP) biomarkers: total DAP (driven by diethyl metabolites) was inversely associated with % motility |
| Giulioni C et al 2021 · Andrologia | meta-analysis | mixed | moderate | Meta-analysis of cohort studies in 'workers or general populations' (route not separated): pyrethroids reduced only normal morphology (WMD -7.61%, 95% CI -11.92 to -3.30), while organophosphates reduced ejaculate volume (WMD -0.47mL), sperm |
| Knapke ET et al 2022 · Toxicology | observational | mixed | moderate | Navigation Guide systematic review of 19 studies (environmental AND occupational combined, not separated; n=42-2122, 14 countries, 2012-2021) rated evidence 'sufficient' for toxicity to sperm motility (63% of studies) and DNA integrity (80% |
| Liu Z et al 2025 · study_type: observational | observational | mixed | moderate | Cross-sectional couples study (n=211 ART patients, general population - not occupational), seminal-plasma/serum/follicular-fluid neonicotinoid biomarkers: seminal thiamethoxam linked to reduced cleavage rate/pregnancy rates, but this measur |
| Wang Z et al 2025 · study_type: observational | observational | mixed | moderate | Cross-sectional study (reproductive-age men, Jinhua China, general population - not occupational), plasma biomarkers: pesticide (p,p'-DDE, bifenthrin) detection frequencies were 21-67%, and DDE was negatively correlated with sperm viability |
| Carvalho RK et al 2026 · study_type: animal | animal | mixed | moderate | EXPERIMENTAL ANIMAL study (Wistar rats, herbicide mixture S-metolachlor+flumioxazin, 250/500/1000 mg/kg/day gavage x28 days - doses far above any human dietary or occupational exposure): sperm production, mature spermatids, and DNA integrit |
| Perry MJ. 2008 · Human reproduction update | observational | mixed | moderate | Landmark Human Reproduction Update systematic review (environmentally AND occupationally exposed men, not separated, prior 15 years) found 13/20 semen-quality studies, 3/6 DNA-damage studies, and 4/6 aneuploidy studies positive; authors the |
| da Costa IR et al 2026 · study_type: animal | animal | mixed | moderate | EXPERIMENTAL ANIMAL study (30 Wistar rats, chlorpyrifos 5 or 15 mg/kg gavage x40 days, peripubertal): sperm MOTILITY was unchanged, but epididymal sperm transit time increased (5mg/kg) and mitochondrial activity decreased (15mg/kg), with re |
| Tang W et al 2025 · study_type: observational | observational | mixed | moderate | Cross-sectional study (796 Chinese sperm-bank donors, general population - NOT occupational), urinary biomarkers including OP-pesticide metabolites DMTP/DEP: highest tertile of DMTP and DEP showed small motility reductions (-3.81%, 95% CI - |
| Martenies SE et al 2013 · Toxicology | observational | mixed | moderate | Systematic review of 17 studies (2007-2012, environmental OR occupational, not separated) found 15/17 reported significant semen associations across DDT/HCH/abamectin/pyrethroid/organophosphate exposures; decreased concentration was the mos |
Disagree, or know a study we missed?
We grade by evidence, not opinions. The way to weigh in is to point us to a study we haven't cited (check the evidence table above first), or to flag a problem with one we have. Every submission is reviewed; if it holds up, the grade updates and shows in Science Changes Its Mind.
Opens a short form. You'll sign in with Google so submissions are tied to a real account — we don't display your identity, and we only accept a link we can verify (PubMed, DOI, ClinicalTrials.gov).
Educational only, not medical advice. Grades and scores reflect published evidence weighted by study design and quality; see the methodology.