ISIS Report 25/04/07
Mobile Phones and Vanishing Bees
The recent boom in third generation mobile phones may be the main culprit
for colony collapse disorder in honeybees. Dr.
Mae-Wan Ho
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Colony collapse a new phenomenon
Bees worldwide have been involved in a disappearing act called “colony collapse
disorder” over the past two years [1] (Mystery
of Disappearing Honeybees, this series), with little sign of the disease
or infestations that have resulted in massive loss of colonies in the past.
The bees simply leave the hives and fail to return. Beekeepers and scientists
alike are stymied as to the cause of this strange phenomenon.
One likely culprit is a new class of systemic pesticides, which are not only
sprayed on crops, but also used universally to dress seeds in conventional agriculture,
and can confuse and disorientate bees at very low concentrations [2] (Requiem
for the Honeybee, this series). Another candidate is radiation from mobile
phone base stations that has become nearly ubiquitous in Europe and North America
where the bees are vanishing; this possibility is considerably strengthened
by preliminary findings that bees fail to return to the hives if cordless phone
base stations are placed in them.
Simple experiment with dramatic results
Researchers at Landau University in Germany designed a simple
experiment for students on the Environmental Science course [3]. Eight mini-hives,
each with approximately 8 000 bees were set up for the experiment. Four of
them were equipped with a DECT (Digital Enhanced Cordless Telecommunication)-station
at the bottom of the hive, and the other four without the DECT-station served
as controls.
At the entrance of each
hive, a transparent plastic tube enabled the experimenters to watch the marked
bees entering and leaving the hive, so they can be counted and their time
of return after release recorded for a period of 45 minutes.
The experimenters also studied
building behaviour by measuring the area of the honeycomb and its weight.
In the course of the experiment,
three colonies exposed to mobile phone radiation and one non-exposed control
colony broke down. The total weights of the honeycombs in all colonies, including
those at the time of breakdown were compared. The controls weighed 1 326g,
while those exposed to the DECT-stations weighed only 1 045g, a difference
of 21 percent. The total area of the honeycomb in the controls was 2 500,
compared to just 2050 in the exposed hives.
But it was the number of
returning bees and their returning times that were vastly different. For two
control hives, 16 out of 25 bees returned in 45 minutes. For the two microwave-exposed
hives, however, no bees at all returned to one hive, and only six returned
to the other.
Cordless phone base station widely used in homes and offices
These dramatic results are of a preliminary nature, but one should bear
in mind that the DECT-station is a simple cordless phone base, widely used
in homes and offices.
It emits microwave radiation of about 1 900 MHz continuously, which is
frequency modulated at 100 Hz. The average power is 10 mW, with a peak of
250 mW. It represents the exposure levels of perhaps tens of millions worldwide
living near mobile phone base stations, or have cordless phones in their homes
or offices.
The same scientists had carried out an earlier experiment with the cordless
phone base on a standby mode, in which the average power is 2.5 mW, and that
appeared to have had no effect on the bees [4, 5].
Clearly the present findings need to be taken much further, but their significance
should not be downplayed for a number of reasons. The findings are compatible
with evidence accumulating from investigations on many other species including
humans, showing that mobile phone radiation is associated with a range of health
hazards including cancers [6] (Drowning
in a Sea of Microwaves, SiS 34). Furthermore, bees are known to be
extremely sensitive to magnetic and electromagnetic fields, and there have been
many suggestions that they could be used as an indicator species for electromagnetic
pollution.
Bees as indicator species for electromagnetic pollution
Experiments dating well back to the last century have documented the phenomenal
sensitivity of honeybees to electromagnetic fields. Bees use the earth’s magnetic
field to navigate. Free-flying honeybees are able to detect static intensity
fluctuations as weak as 26 nT against the background earth-strength magnetic
field (average 500 mT) [7]. This has been demonstrated in
experiments where individual honeybees have been trained to discriminate between
the presence and the absence of a small static magnetic anomaly in the lab.
Honeybees can also learn to distinguish between two 360o panoramic
patterns that are identical except for the compass orientation. In this case,
the difference was a 90o rotation about the vertical axis [8].
The most powerful cue to direction for the honeybee comes from the sky, but
discrimination between patterns is possible in the absence of celestial information,
as when the sky is overcast. Under those conditions, bees can use a magnetic
direction to discriminate between patterns.
The bees’ waggle dance on
the honeycomb, which tells hive mates where to find food, can also be misdirected
by anomalies in the earth’s magnetic field or very weak pulsed magnetic fields
at about 250 MHz applied in the correct direction [9]. Bees can even learn
to detect very low levels of extremely low frequency alternating electromagnetic
fields [10].
But mobile phones have been around for close to 20 years, so why now? There
has been a recent change in cell phone technology that coincides with the current
crisis. At the beginning of the present century, 3G (third generation) mobile
phone systems became publicly available, leading to a surge in popularity of
mobile phones, and many more phone towers [11]. Bees are disappearing in North
America, Europe and also Australia, wherever mobile phones are greatly in use.
Stay tuned.
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