Overview
- A peer-reviewed systematic review and meta-analysis published in Occupational & Environmental Medicine in early August 2026 found that people with workplace pesticide exposure had about a 60 to 70 percent higher chance of developing ALS compared with unexposed people.
- The pooled data showed larger effects at higher exposure levels with near tripling of risk in the small set of studies that measured heavy exposure and roughly doubling of risk at lower exposure levels.
- Herbicides produced the strongest association at about 70 percent higher risk while insecticides and fungicides were linked to roughly 60 percent higher risk in the pooled estimates.
- The association appeared in men but not women in the studies that reported sex-stratified results, though authors and outside experts warn this finding is based on limited data and could reflect study flaws.
- The evidence rests on 11 mainly retrospective studies with about 2,000 MND/ALS cases and indirect exposure measures such as job histories or self-report, so researchers call for workplace exposure reductions now and for higher-quality prospective studies to test causation.