Hi again,
 
The nature of your second question may have relevance to the list, so I
will respond to the group.  Further discussion may warrant going off the
list.
 
Fluoride is a  hotly debated issue.  Not all of my research colleagues
agree with me on this one, but I stubbornly maintain that we do know what
is happening.
 
Fluoride is not good for bees.  It accumulates and even concentrates in
bees.  There are many reports of fluoride toxicity to bees from the older
U.S. and European literature.  We have investigated several cases of
severe bee poisoning and agree with these reports - fluoride is harmful
to bees, at least when it accumulates to high levels.
 
Now for the caveat.  Fluoride poisoning does not occur in the same manner
as poisoning from an organic insecticide.  There is at least one paper
published in the U.S. in the last few years that contends that we are all
wrong and that fluoride is not a problem.  I disagree and believe that
the study was not conducted in a manner that could or would reveal
fluoride poisoning.
 
Here is a summary of what we have learned about fluoride and honey bees
over the last 20 years.  Beekeepers near aluminum smelters, oil
refineries, phosphate plants, or in areas where the water is high in
fluoride (either naturally, such as occurs in deep artesian wells in MT
or fluoridated, as in city water supplies) will have elevated F in their
bees.
 
What is elevated?  Well, on a dry weight basis, we find that bees can
vary from <0.5 ppm of F to as high as 220 ppm of F.  Levels of 5-15 ppm
are fairly common over much of the northwest and in bees from Florida.
Levels above 20 ppm suggest a source, and we classify any sample with
concentrations of more than 40 ppm as elevated.  Bees from urban areas
often have F in the 20-40 ppm range.  Rural bees generally are less than
20 ppm, unless the water contains F.
 
Bees near refineries tend to range from 40-80 ppm.  Phosphate plants
often up the levels to more than 120 ppm.  Aluminum smelters also
contribute lots of F to bees.  On an island between Canada and New York,
with aluminum smelters on both sides, the F levels went over 200 ppm.
 
Bees appear to get F from most of these industrial sources via emissions
into the atmosphere (air borne, probably in a gaseous form).  In these
situations, the F levels will be about 2xs higher in forager bees than in
nurse bees.  You may not be able to detect elevated levels of F in the
larvae or pupae.
 
Mark Dewart, UM, did his thesis on F.  He found that F levels in bees
near an aluminum smelter in western MT were highest in forager bees,
orders of magnitude higher than levels in forage plants, and much higher
than F levels in water from that region.  Most importantly, using
regresson techniques, he found that bees reflected F levels in the air
much better than F levels in water or plants.  Other studies have not
been able to show this, but those studies used 3 apiaries and one air
monitoring station.  Mark used 11 apiaries and lines of format plates to
quantify air levels throughout the bees forage range.  This gave us a
much better picture of regional gradients of exposure to F and much more
powerful statistics.
 
Also, the smelter put on additional abatement equipment and curtailed
(down-sized) their operations over a 10 yr period.  The amount of F
released to the air decreased as did the residue levels in bees.
 
We have a paper under review at this time that reports on F from multiple
sources in Idaho.  Both this paper, and one that we published in the Feb.
5, 1985 issue of SCIENCE provide isopol maps of F dispersion over
landscape size areas.  The bottom line is that we can often follow F
dispersion for 60 to 90 miles from a large industrial source.
 
Years ago (in the 70s), we published a series of reports on F in bees in
eastern MT before and after a group of coal-burning power plants went on
line.  These power plants used sophisticated scrubbers and low sulfur
coal.  The levels in F prior to the power plants going on line averaged
about 8 ppm.  Within a year of the power plant startup, the F levels in
bees within 20-30 miles in the downwind directions from the power plants
average 20-30 ppm.  Now, I don't think this was enought to cause any
problems to the bees, but three points need to be made:
 
1) The beeyards displaying elevated F were along the same transects as
the plume path (from the 500+ ft smokestacks) as followed by helicopter
sampling of the plume and by a form of radar tracking,
 
2) The beeyards showed elevated F at 3 times farther from the power
plants than did could any instrument,
 
3) The smokestacks were reported to only emit 7 pounds of F per day.
That is not much, considering that we once studies a copper smelter
emitting 1/2 - 1 ton of arsenic per day.  These power plants consume coal
at such a fast rate that the unit train bringing the coal to the plant
never stops moving, it just continuously dumps coal from the cars into
the hoppers of the furnaces.
 
The paper that says F doesn't harm bees used a few colonies of bees at 3
locations and monitored them for a few months.  They saw F at levels
exceeding 180 ppm and didn't get piles of dead bees.
 
Our observations of kills from F indicate that it is about like looking
at mite damage.  Sometimes you have high mite levels and little impact,
other times even low infestations seem to destroy the colonies or at
least severely set them back.
 
Our observations of F toxicity come from two sources:
 
1) Commercial beekeepers running several thousand colonies over more than
100-200 yards for more than 10 years
 
2) Migratory beekeepers moving bees in and out of smelter regions.
 
 
Ok, as far as the commercial people go, they have records indicating that:
 
1) Bee kills occur every few years.  These kills generally occur in the
spring during spring buildup or during periods of nectar dearth.
 
2) The bees always die at the same yards, usually downwind from the
industrial source.  There is almost always a gradient, with bees at yards
closest to the source getting hit the hardest.
 
3) Residue levels in these dead bees normally exceed 120 ppm.
 
With respect to the migratory people, they report losses when moving into
an industrial area after coming out of stressful conditions such as
orchard pollination.  The bees looked ok or good before being moved, then
dropped rapidly after been set down in the industrial region.  Again, F
levels in forager bees exceeded 120 ppm.
 
Finally, in the early 70s, while study the power plants, we found that
bees at one yard had 80-150 ppm of F, yet were far from the power plants,
in the upwind direction, in a rural setting.  We found that the source
was water from an artesian spring.  The spring fed a cattle watering tank
and overflowed onto the ground.  Water in the well ranged from 1-3 ppm of
F, that in the water tank somewhat higher, that in the muddy puddles
where the bees were gathering water on hot days exceeded 11 ppm (in the
water).
 
This pattern was consistent over several years.  Finally, we asked the
commercial beekeepers, who had several hundred beeyards, how that
particular yard performed.  The yard was near a river, the land was
irrigated, and the floral resouces excellent.  George paused, then
launched into a history of that yard, which he thought suffered from
being too close to his house.  In other words, some years he left it
until last (always thinking he could drop off a few supers on the way
home).  Other years, he grafted queens at that yard, because it was
convenient.  Bottom line, every year the yard did poorly in terms of
colony vigor and productivity, but George figured he was the cause.
 
I suggested he move the bees to the other side of the river (since the bees
wouldn't cross a large river to get to the artesian well).  George moved
the bees, but only about 1/10 mile and on the same side of the river.  He
figured that the bees would use river water rather than fly the extra
distance to the well.  Apparently some of these colonies had a long
memory.  The next summer, some of his colonies in that yard had high F,
some intermediate, and some low.  We observed marked bees at the well
coming from his beeyard on the river.  That year, colony performance was
spotty, but the yard did better overall.  The next year, George put the
bees on the opposite side of the river.  His colony vigor increased and
he doubled his yard average in terms of honey produced.  Oh yes, no more
elevated F in the bees.
 
So, I leave it to you to draw your own conclusions.  Can you have bees
with 180-200 ppm F and no obvious toxicity - I say yes, if the bees are
in otherwise good condition and are not being too heavily stressed by
other factors such as overwintering, poor nutrition, mites, etc.
 
Can one adequately test for F toxicity over short periods of times using
only a few colonies, I say no, the chronic effects may take a long time
to be evidenced or may only appear when the colonies are heavily stressed
by other factors.
 
Would I put bees where either the water or air had elevated F?  NO!
 
Do I think beekeepers suffer losses from F?  YES!  And most importantly,
the losses may be hidden (i.e., poor vigor, reduced disease resistance,
lowered productivity).
 
 
If you want to gamble, expose your bees to F, you might get away with it.
 
 
If every so often, your bees die or just don't do well, I won't be surprised.
 
Jerry J. Bromenshenk
The University of Montana
Missoula, MT  59812-1002
 
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