Sorry for the OT post but would really appreciate the advice,and I know
people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just been
sent 50m up a mast with live microwaves (for mobile phones), with VHF
radio transmission for TV and radio on the same mast 50m above that;
having been assured it was perfectly safe to do so but has subsequently
found out that this was pure supposition. Ha bloody ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably it's
going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful advice I
can relay back to him urgently I'd be really grateful. Anything else I
need to ask him?

Thanks
David

Lobster wrote:
Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably it's
going to be pretty powerful.

If anybody could point me at some guidelines

Googling about, the NRPB (National Radiological Protection Board - now
part of the health protection agency) has this document on the effects
and their recommendation.

http://www.hpa.org.uk/web/HPAwebFile.../1194947415497

More links at
http://www.hpa.org.uk/web/HPAweb&HPA.../1195733817602

--
Adrian C

In message , Lobster
writes
Sorry for the OT post but would really appreciate the advice,and I know
people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just been
sent 50m up a mast with live microwaves (for mobile phones), with VHF
radio transmission for TV and radio on the same mast 50m above that;
having been assured it was perfectly safe to do so but has subsequently
found out that this was pure supposition. Ha bloody ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably it's
going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful advice
I can relay back to him urgently I'd be really grateful. Anything else
I need to ask him?

Thanks
David



You might try asking on uk.tech.broadcast some very knowledgeable
people on there.


--
Bill

Lobster wrote:
Sorry for the OT post but would really appreciate the advice,and I know
people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just been
sent 50m up a mast with live microwaves (for mobile phones), with VHF
radio transmission for TV and radio on the same mast 50m above that;
having been assured it was perfectly safe to do so but has subsequently
found out that this was pure supposition. Ha bloody ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably it's
going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful advice I
can relay back to him urgently I'd be really grateful. Anything else I
need to ask him?

Thanks
David

No-one here can say if that was safe or not.

If he was 50m below the main VHF aerials, then there is no need to
worry. Field strengths directly behind these would certainly be higher
than that which is considered to be safe, although some are adequately
screened so that one is able to climb through safely but not linger there.
Cellphone panels have little radiation back towards the mast. The powers
are also much lower than broadcast. As long as he was not in front of
these panels, then there is little risk. Same goes for dishes.
Cellphone antennas using "co-linears" (an omni-directional vertical) are
renowned for high field strengths but that doesn't extend far above and
below.

Physical exposure to high levels of non-ionising radiation causes the
body to heat-up so hopefully, he didn't notice anything like this whilst
on the structure.

HSE publishes exposure limits but unless a hazard meter is available,
this cannot be checked.

In the UK, each mast has a safety survey which shows the field strengths
and lists the measures to be taken when work is to be carried out at
each height.

If your friend is a trained rigger, he should know all this anyway. If
he is not, then what is he doing working on transmitter masts?

A

[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Lobster wrote:
Sorry for the OT post but would really appreciate the advice,and I
know people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just
been sent 50m up a mast with live microwaves (for mobile phones), with
VHF radio transmission for TV and radio on the same mast 50m above
that; having been assured it was perfectly safe to do so but has
subsequently found out that this was pure supposition. Ha bloody ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably
it's going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful advice
I can relay back to him urgently I'd be really grateful. Anything else
I need to ask him?

No-one here can say if that was safe or not.

If he was 50m below the main VHF aerials, then there is no need to
worry. Field strengths directly behind these would certainly be higher
than that which is considered to be safe, although some are adequately
screened so that one is able to climb through safely but not linger there.
Cellphone panels have little radiation back towards the mast. The powers
are also much lower than broadcast. As long as he was not in front of
these panels, then there is little risk. Same goes for dishes.
Cellphone antennas using "co-linears" (an omni-directional vertical) are
renowned for high field strengths but that doesn't extend far above and
below.

Physical exposure to high levels of non-ionising radiation causes the
body to heat-up so hopefully, he didn't notice anything like this whilst
on the structure.

HSE publishes exposure limits but unless a hazard meter is available,
this cannot be checked.

In the UK, each mast has a safety survey which shows the field strengths
and lists the measures to be taken when work is to be carried out at
each height.

If your friend is a trained rigger, he should know all this anyway. If
he is not, then what is he doing working on transmitter masts?

Many thanks for that advice Andy, much appreciated: sounds reasonably
encouraging.

He's a trained rope-worker for sure, whether that normally covers
transmitter masts I have no idea - but pretty sure this is the first
time he's been asked to work on one, anyway. But God knows what rules
and regs apply in the country he's working in :-( Wouldn't be my first
choice of employer/employment, that's for sure...

Any further comments from anyone much appreciated.

David

Lobster wrote:
[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Lobster wrote:
Sorry for the OT post but would really appreciate the advice,and I
know people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just
been sent 50m up a mast with live microwaves (for mobile phones),
with VHF radio transmission for TV and radio on the same mast 50m
above that; having been assured it was perfectly safe to do so but
has subsequently found out that this was pure supposition. Ha bloody
ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what
he's likely to have done to himself and if there's anything he can do
now?
Apparently this is a main mast for the whole country so presumably
it's going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful
advice I can relay back to him urgently I'd be really grateful.
Anything else I need to ask him?

No-one here can say if that was safe or not.

If he was 50m below the main VHF aerials, then there is no need to
worry. Field strengths directly behind these would certainly be higher
than that which is considered to be safe, although some are adequately
screened so that one is able to climb through safely but not linger
there.
Cellphone panels have little radiation back towards the mast. The
powers are also much lower than broadcast. As long as he was not in
front of these panels, then there is little risk. Same goes for dishes.
Cellphone antennas using "co-linears" (an omni-directional vertical)
are renowned for high field strengths but that doesn't extend far
above and below.

Physical exposure to high levels of non-ionising radiation causes the
body to heat-up so hopefully, he didn't notice anything like this
whilst on the structure.

HSE publishes exposure limits but unless a hazard meter is available,
this cannot be checked.

In the UK, each mast has a safety survey which shows the field
strengths and lists the measures to be taken when work is to be
carried out at each height.

If your friend is a trained rigger, he should know all this anyway. If
he is not, then what is he doing working on transmitter masts?

Many thanks for that advice Andy, much appreciated: sounds reasonably
encouraging.

He's a trained rope-worker for sure, whether that normally covers
transmitter masts I have no idea - but pretty sure this is the first
time he's been asked to work on one, anyway. But God knows what rules
and regs apply in the country he's working in :-( Wouldn't be my first
choice of employer/employment, that's for sure...

Any further comments from anyone much appreciated.

David


For future reference, the first signs that you are being irradiated is
usually tingling in the ears, and as others have said if he was behind
the antennae he was probably safe, in front of them NOT. most are highly
directional to ensure they get max range.

Vernon wrote:

For future reference, the first signs that you are being irradiated is
usually tingling in the ears, and as others have said if he was behind
the antennae he was probably safe, in front of them NOT. most are highly
directional to ensure they get max range.

As a licensed radio ham, I have to ask the question of 'why the tingling
in the ears?'


Dave

On Thu, 15 Oct 2009 19:29:50 +0100, Lobster
wrote:

Sorry for the OT post but would really appreciate the advice,and I know
people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just been
sent 50m up a mast with live microwaves (for mobile phones), with VHF
radio transmission for TV and radio on the same mast 50m above that;
having been assured it was perfectly safe to do so but has subsequently
found out that this was pure supposition. Ha bloody ha.

Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?
Apparently this is a main mast for the whole country so presumably it's
going to be pretty powerful.

If anybody could point me at some guidelines or has any helpful advice I
can relay back to him urgently I'd be really grateful. Anything else I
need to ask him?


Ask on uk.tech.broadcast

My info is 35+ years out of date although the physics doesn't change.

Personally I'd say that if he kept out of the useful beam (the
antenna's didn't point towards him like a searchlight) and he was 50m
away then he'd be alright.

The principal risk is of R.F. heating affecting the eyes in
particular causing cataracts and some other organs to a lesser extent.

There is no risk of hidden long term damage. If he'd cooked himself I
think he'd know about it, but if they'll take risks like that the
question is what else are they taking chances with.

Accidents have occurred with radio towers over the years, If the
transmitter was suddenly energised whilst he is up there he could end
up panicking and fall off scrabbling to get out of the beam.
Proceadures have been evolved to avoid that possibility.

Derek

"Lobster" wrote in message
...
Sorry for the OT post but would really appreciate the advice,and I know
people here will have the answer...

I've just received a text message from a friend who's working in the
Middle East today doing repair work on big radio masts. He's just been
sent 50m up a mast with live microwaves (for mobile phones), with VHF
radio transmission for TV and radio on the same mast 50m above that;
having been assured it was perfectly safe to do so but has subsequently
found out that this was pure supposition. Ha bloody ha.

If he only got as far as the mobile phone bit and didn't hang about in front
of a microwave link i don't see there is a problem.
In general the power is radiated away from the mast so being inside or below
it means low power levels.

"Lobster" wrote in message
...
[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?

So far I don't think we've had a response covering the future symptoms that
might develop. If he endured the exposure without being aware of any ill
effects, does that mean there will be no future problems?

Bill

In message , Bill Wright
writes

"Lobster" wrote in message
...
[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?

So far I don't think we've had a response covering the future symptoms that
might develop. If he endured the exposure without being aware of any ill
effects, does that mean there will be no future problems?

I hope not - I spent a lot of time up telecom towers when I worked in
Indonesia

Nothing wrong with me

No sireee
e
e
e

AArgh

--

geoff

In article ,
"Bill Wright" writes:

"Lobster" wrote in message
...
[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?

So far I don't think we've had a response covering the future symptoms that
might develop. If he endured the exposure without being aware of any ill
effects, does that mean there will be no future problems?

Certain body organs are particularly susceptable to damage from
even a small amount of radiation induced heating and/or their
composition makes them more susceptable to absorb the energy.
Lenses in the eye form cataracts, but I believe that's pretty
instant (same effect as cooking egg white).
Kidneys are another, but it can take you a few days to realise
kidneys have stopped working (or even longer if they haven't
completely stopped). Also depends on the wavelength, at what
depth below the skin the heating effect takes place.

--
Andrew Gabriel
[email address is not usable -- followup in the newsgroup]

"Andrew Gabriel" wrote in message
...
In article ,
"Bill Wright" writes:

"Lobster" wrote in message
...
[added x-post to uk.tech.broadcast - thanks for the suggestion Bill]

Andy Dee wrote:
Understandably he's now very worried and upset. He's asked me to find
out anything I can about UK guidelines, radiation risks etc; what he's
likely to have done to himself and if there's anything he can do now?

So far I don't think we've had a response covering the future symptoms
that
might develop. If he endured the exposure without being aware of any ill
effects, does that mean there will be no future problems?

Certain body organs are particularly susceptable to damage from
even a small amount of radiation induced heating and/or their
composition makes them more susceptable to absorb the energy.
Lenses in the eye form cataracts, but I believe that's pretty
instant (same effect as cooking egg white).
Kidneys are another, but it can take you a few days to realise
kidneys have stopped working (or even longer if they haven't
completely stopped). Also depends on the wavelength, at what
depth below the skin the heating effect takes place.


All those effects are from direct RF heating tissue. Fortunately for the
OP's friend the levels required to do damage are actually quite high. Most
wavelengths are either reflected by flesh (water), and of the transmitted
power into the body, it's quickly absorbed. I wasn't aware that cataracts
formed so quickly. One would have thought more cataracts would be formed by
standing close to fires.

My instinct does suggest that working behind mobile radio aerials would pose
little danger, the maximum power emitted would be in the region of 30W
forward. As long as he stayed within the confines of the mast, I doubt
there would be much power in the VHF band, especially 50m away from those
aerial.

I would say that he ought to take more care though, and only climb a mast
which has been surveyed for field strength. It seems this one hadn't?