

Study Finds Pesticides Linked to Depression in Farmers - Mz
http://modernfarmer.com/2014/11/landmark-20-year-study-finds-pesticides-cause-depression-farmers/

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jph
To read the actual paper:
[http://ehp.niehs.nih.gov/1307450/](http://ehp.niehs.nih.gov/1307450/)

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."

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keenerd
Did they control for crop loss and farmer knowledge?

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.

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dingdingdang
This question should really be answered (props for bringing it up), without
that being the case the value of the research is severely compromised!

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keenerd
It looks like one of the factors was "cumulative days use of any pesticide".
However this did not take plot size into account - a farmer with a large plot
and an appropriate use of pesticides is in the same category as a farmer with
a small plot and an overuse of pesticides.

"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)

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Yeroc
Having grown up on a farm it is usually the cost of pesticides that trigger
depression!

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mschuster91
The much more interesting question: what do all those biozides do to the non-
targetted wildlife, e.g. cats, dogs, bees, frogs, fish in the downstream of
rivers where the rain accumulates...

At least in bees there are already concerns that massive amounts of biozides
contribute to hive deaths.

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rmason
One statement that I disagree with is the one that farmers apply the majority
of pesticides. In actuality commercial applicators, most likely employees of
commercial fertilizer companies or Coops are applying a very large amount of
total pesticides.

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.

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Houshalter
It seems to be mainly insecticides which are dangerous. This is because
insecticides are by design meant to harm animals, which have much more
biologically in common with us than plants or fungi.

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skittles
Just read about Roundup being commonly used by wheat farmers to "desiccate"
the crop before harvest (allowing for earlier harvest). Maybe this whole
gluten intolerance thing is actually a Roundup intolerance.

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pranjalv123
Given that this study is about pesticides, not herbicides, and glyphosate
(RoundUp) wasn't one of the chemicals tested, I don't think there's any
evidence for that here.

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skittles
I should have put "off topic" in my comment, but I thought it was obvious
since I didn't mention a pesticide or depression. I just thought my comment
might be of interest to anyone that would be reading the post.

