Rotenone, paraquat, and Parkinson's disease.
Level 4 - case-series / case-control
Nested case-control study
PubMed 21269927 · doi:10.1289/ehp.1002839
What was done
In a case-control study nested within the Agricultural Health Study, investigators evaluated lifetime pesticide use classified by biological mechanism (mitochondrial complex I inhibition and oxidative stress induction). Parkinson's disease (PD) was diagnosed by movement disorders specialists. Controls were randomly selected from the cohort and frequency-matched by age, sex, and state at an approximate 3:1 ratio (110 cases, 358 controls).
What was found
Parkinson's disease was associated with exposure to mitochondrial complex I inhibitors overall (odds ratio [OR] = 1.7; 95% CI, 1.0–2.8), including rotenone specifically (OR = 2.5; 95% CI, 1.3–4.7). PD was also associated with pesticides that induce oxidative stress overall (OR = 2.0; 95% CI, 1.2–3.6), including paraquat specifically (OR = 2.5; 95% CI, 1.4–4.7).
Why it matters
This study links mechanistic laboratory models of Parkinson's pathophysiology—specifically mitochondrial dysfunction and oxidative stress—directly to specific pesticide exposures (rotenone and paraquat) in human agricultural workers.
Limits
The sample size is relatively small (110 cases). Lifetime pesticide exposure relies on retrospective self-reporting, introducing risk of recall bias. The findings derive from an agricultural cohort and may not generalize to non-occupational exposures.
Cited by
- supports Farmers who work directly with Paraquat have a 150% increased risk of Parkinson's disease, and people living or working near where Paraquat is sprayed have a 100% increased risk.