Study Finds Pesticides Linked to Depression in Farmers
modernfarmer.com
modernfarmer.com
Results: After weighting for potential confounders, missing covariate data, and dropout, ever-use of two pesticide classes, fumigants and organochlorine insecticides, and seven individual pesticides—the fumigants aluminum phosphide and ethylene dibromide; the phenoxy herbicide (2,4,5-trichlorophenoxy)acetic acid (2,4,5-T); the organochlorine insecticide dieldrin; and the organophosphate insecticides diazinon, malathion, and parathion—were all positively associated with depression in each case group, with ORs between 1.1 and 1.9."
There is a chance that the causal links go like this:
* lack of knowledge -> spray at wrong time
* spray at wrong time -> no pests killed
* no pests killed -> crop loss
* crop loss -> income lost -> depression
* crop loss + lack of knowlege -> spray even more at the wrong times
Thus creating a destructive feedback loop with depression as an accidental side effect of the process. I can say with a high degree of certainty that each single link appears to be true. We'll say 90% confidence factor for each of the five steps, 60% total confidence factor across the whole causal loop.
Knowledge is a huge factor for farming. I can say that from watching my family farm over the past 20 years, that as my family has figured out what to spray and (more importantly) when to spray our pesticide use has dropped and our yields have gone up.
"Farm size" was mentioned in the previously identified confounding factors, but not one that was corrected for in the study after seeing it made no difference? Education was a confounding factor that was accounted for.
"Cumulative days use per acre" would be an interesting factor to test, but varies greatly between various crops and climates. "Crop loss despite pesticide application" would be the real one to measure but that requires a certain degree of god-like knowledge. Days-use-per-acre over time and yields-per-acre over time is probably the best that could be managed, where "time" is at least 5-10 years.
One term in the paper went over my head and I can't find a definition or sufficient context. Does "ever-use" mean a small amount or a large amount? (once-ever or for-ever)
At least in bees there are already concerns that massive amounts of biozides contribute to hive deaths.
I spent twenty years in the fertilizer business as an agronomist. Interestingly a government study back in the nineties found a link between commercial pesticide applicators and depression. In that study it was only insecticides that caused problems. Note a large percentage of those insecticides are no longer applied as extensively because of genetically modified seeds.