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Siarov23909  
#1 Posted : 18 January 2011 20:54:56(UTC)
Rank: New forum user
Siarov23909

Hi there,

My question concerns “Non Ionizing Radiation”.

As a part of roof maintenance, the company I work for will employ subcontractor to undertake repairs for the duration of 12 weeks, on the top of high building, which contains a few mobile phone transmission masts, situated in a very close proximity (less then a meter from the working areas).
Naturally, the usual risks associated with the work activities related to the specific tasks at hand have been evaluated and controlled.
So here comes the “grey area” question: Can anyone shed light regarding the occupational exposure to ”non ionizing radiation” in particular the one generated from mobile phone transmission masts.
I have already consulted with the HSE, IHS, HPA web sites, yet I have to admit the information found was limited and not up to the point. Studies related to the subject are outdated and often filled with technical jargon, which does not simplify the issue.
Unsupported studies show increase likelihood of developing a range of debilitating symptoms, which in some cases may lead to cancer etc.
I have already established that the exposure values in UK differ with regards to “members of the public” and “workers”.
Furthermore, researching the subject added more insight concerning planning permission regulation. Apparently, Mobile Phone masts should not be installed close to schools with a minimum of 250 m being the quoted figure as approved distance.
Maintenance personnel working for mobile phone companies, among many other industries are certainly exposed to “non ionizing radiation” occupationally, but why does it prove difficult to come with simplified way of stating what the occupational exposure limits are and subsequently a weighted average figures produced and approved by one of the many regulatory bodies here in UK in order to assist Safety Practitioners. Would you suggest that relying on the companies’ own database, should they decide to share it, is considered to be credible, or would you rather take your own measurements and act accordingly.
In an ideal world following the hierarchy of control, the elimination approach (switching the masts off) should serve the purpose, yet I am dreading this will prove impractical, so your suggestions to limiting the exposure in addition to any advise or sample RA/MS would be greatly appreciated.
Regards.
Seamusosullivan  
#2 Posted : 18 January 2011 23:41:59(UTC)
Rank: Forum user
Seamusosullivan

Hi,

I was once told by a mobile phone operator that the operators of these antenna and link dishes, can switch these off, but they do require plently notice. Their contact numbers will be atached to the door leading onto the roof (if that is how access is achievied). The phone service may remain unaffected as the operators will turn up the power in the adjacent cells ( there is an overlap of these cells).

There is a good chance that there will be more than one operator on this site, so you may need to contact a few firms. The antenna may be numbered, but you might not be sure of whoses antenna is owned b who.

While they can switch off one or indeed more of the antenna remotely, I would insist on their engineer going out to the site and confirming that they are switched off.

People with electronic implants may be affected, eg pacemakers


As far as I remember there is some standard that the antenna and link disk is supposed to be kept 1.5 meters away from humans, I stand corrected on that figure. I also remember something that if you walk in front of the link dish (looks like a mini satelite dish), you trip out some signal???

I am sure someone will answer this in more detail tomorrow.

chris.packham  
#3 Posted : 19 January 2011 09:03:21(UTC)
Rank: Super forum user
chris.packham

This is a point that has always intrigued me. What is the difference between the radiation emitted by a mobile phone and that of the transmitter? After all, the power from the mobile phone must be sufficient to interface with the transmitter and a mobile phone is held directly against the head, i.e. in close proximity to the brain.

Chris
Chrisrsp  
#4 Posted : 19 January 2011 09:19:18(UTC)
Rank: Forum user
Chrisrsp

'''Awaits Jane Blunts' input on this...'''
johnmurray  
#5 Posted : 19 January 2011 12:10:18(UTC)
Rank: Super forum user
johnmurray

The handset interfaces with base station. This then commands
different levels of power for the handset transmitter, and a change
of frequency. The base output power does not vary from h/set
to h/set. Since the base antennas exhibit considerable
gain a person within a very short distance from the transmitter
antenna on the base could be exposed to several hundred
watts of rf. That exposure is reduced by distance, double the
distance quarters the power. The handset power is about one watt.
Same power reduction with distance.
barnaby  
#6 Posted : 19 January 2011 12:18:08(UTC)
Rank: Guest
Guest

I haven’t looked at this for some years but when I last did the HPA was a good source of rational* advice. These are basic summaries from their website but a search should reveal a lot more detailed information.

Phones
http://www.hpa.org.uk/To...hones/info_MobilePhones/

Masts
http://www.hpa.org.uk/To...hones/info_BaseStations/


This SIM may be of some assistance to the OP. See Appendix 1, though it is broader than just mobile phone masts.
http://www.hse.gov.uk/fo...ctors/cactus/5_01_50.pdf

I’m sure a search of HSE and HPA sites will elicit the information required.



*Well rational to me. Not everyone agreed at public meetings etc. The way some people spoke at the time we should be seeing phone related epidemics by now.
sgd20000  
#7 Posted : 19 January 2011 12:23:25(UTC)
Rank: Forum user
sgd20000

The antennas are the issue here if you will be working 1 metre away, you need to contact the mobile operator to arrange an outage. Remember plenty of notice, as previously mentioned you don't want a 'soft' shut down done remotely - request a engineer attendance to site 'hard' shut down.

You can work right up to the transmission dishes, as they operate at extremely low power - the Orange ones do anyway, not sure about the rest.

Operators use the guideline set out by ICNIRP, occupational safety distances.
johnmurray  
#8 Posted : 19 January 2011 13:51:23(UTC)
Rank: Super forum user
johnmurray

The engineers would like to be told, even if only
Prevent damage to the transmitters !
Funnily enough the parabolic (dish) antennas
Are the ones to avoid, their output frequency
is much higher than the mobile phone base-to-handset
Transmitters and their gain higher, typically 30db.
So an output of one watt into a 30db gain dish
would result in an erp of 1000 watts. At 10 (ish) Ghz
the eyes are under threat.
Siarov23909  
#9 Posted : 19 January 2011 17:54:59(UTC)
Rank: New forum user
Siarov23909

Thanks for the responses guys.
We are meeting with the client and representatives from the mobile phone company to establish what the particular emission values of the antennas and transmission units are, before we finalize our approach with regards to implementing suitable and sufficient control measures.
It is an interesting topic, which has been bugging me for some time and it just happened that I had to research it as apart of my occupational day-to-day safety duties.
Regards,
Jane Blunt  
#10 Posted : 19 January 2011 20:51:12(UTC)
Rank: Super forum user
Jane Blunt

Chrisrsp wrote:
'''Awaits Jane Blunts' input on this...'''


I'm flattered - but it isn't one of my areas of expertise!
johnld  
#11 Posted : 20 January 2011 17:05:57(UTC)
Rank: Forum user
johnld

I had this situation a number of years ago.

Within the immediate proximity of the transmitters it is possible to exceed the exposure levels in the codes of practice.

As Johnmurrey says the power fall of as it is distance dependent, it is the inverse square rule if I remember correctly

Unfortunately we discovered that the transmission company were not very helpful and restricted the times when they were prepared to close the transmitters down

The contracts they have with your site will be very restrictive.

We finally agreed block times when they would shut down during the day.


I suspect you will have big problems if you need a full 3 month shut down. Unless there is another transmitter site close

Its worth remembering that some high buildings have TV boosters on them to cover blind spots

And in some cases also have to be shut down while roof maintenance is carried
out

The natives do get restless if they can not get Corrie or Eastenders.
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