Posted By Chris Shaw Good morning, We have recently been appointed to carry out some roofing recovering / repair work to a high level roof. Mounted on the roof are an array of transmitters, masts and dishes. We will be contacting the client for the details of the owners of the equipment to ask their advice and guidance together with any restrictions which may be imposed. But from an independent source, can anyone advise if they have had experience of this type of work and highlight any possible health implications and safe guards which may be required when carrying work out in such close proximity to this type of equipment. Thanks Chris

Posted By Dave Dowan Hi I would suggest you should of course carry out a risk assessment, this will include asking the landlord for information about transmission equipment, exclusions zones etc. In addition your guys should be trained about RF hazards and controls and be able to use a RF monitors. Hope this helps Dave

Posted By Seamus O Sullivan Hi Cris A total shut down of antenna may be required. Often when the mobile phone engineers go up on the roof to carry out repairs they require a shut down of some antenna.They do not like to pass antenna!!! The moblile phone companies will require advance notice as usually the cells overlap, and antenna can be switched off remotely. If they have advanced notice they can still offer a phone service without the existing antenna. There is suppose to be an exclusion zone around the antenna. Usually three antenna per mobile phone operator is the norm with some link dishes. A phone engineer once told me that he was physically sick up on a roof while doing sone service work which lasted a few hours, it appears he did this type of work on several occasions but was sick once, he went back a few days later only to discover an antenna( belong to another operator) was just at his head level hidden behind some plastic type panel. Also ensure no one has a heart pacemaker while up on the roof, (just in case of problems) Also with the work you are planning to do, you need to see if you need to get the cables , or cables trays lifted. Some of the roofs i have seen had lots of cable trays, the operators sometimes do not share the cable trays, so i would go for a total shut down of all the antenna while you are doing the work. Seamus

Posted By Garry Homer Hi Chris A little late with my response, holidays etc. You or your client need to identify the operators involved and contact them. They will usually send one of their engineers out to assess what you are doing and where your people will need to access. If you need to work close to the transmitting antennas, then a shutdown will be arranged and you should receive documentation to that effect. Personal monitors cost £1,000 upwards and when worn are only effective for antennas that are in front of you, 180 degree coverage, so care needs to be taken if reliance is placed on one of these units. Could fit one on stand facing the antennas. In my 8 year experience of measuring emissions on rooftops I have found only a few instances where an exclusion zone on the main roof of the building was justified. This was where antenna panels are mounted on short poles near the edge of the roof at head/chest height without a barrier to stop you stepping in front of the antenna. Any mobile phone equipment mounted on the higher lift motor room roof is highly unlikely to powerful enough to be of any concern if you are only on the lower main roof of the building due to their directional properties both horizontally and vertically. Some of the small microwave link antennas, the small drum shaped antennas, are so low powered as to be safe to touch. A claim by Orange that I have not found to be wrong for their equipment. Extremely few buildings have anything as exotic as a radar antenna but they do exist. A problem in some cities is the pirate radio. One such installation used a handrail as its antenna! All the necessary warning notices the hse would expect to see are not always present, so take care, get the mobile phone engineer on site and use his knowledge to highlight anything else. As for people feeling sick near mobile phone antennas, a recent report shows this to be in their heads, that is, more about imagination and than anything else. Garry

Posted By Garry Homer The output from mobile phone antennas are not as powerful as microwave ovens. The ICNIRP guidelines for these frequencies are such that whole body heating is limited to approximately 0.1 degree C at the maximum permitted occupational exposure level. Also as any heat gain is time dependant, the guidelines also have a time element and the values can be averaged up to 6 minutes. This means it is possible to walk up to a mobile phone antenna panel, touch its weather cover and walk away again without exceeding the guidelines. The exclusion zone values stated earlier in this thread are necessary for constant occupation within the zone areas to ensure the ICNIRP guidelines are complied with. Actual operational power levels are always found to be less than the theoretical maximum transmission powers used in defining the exclusion zones. Material produced by IOSH on this subject supports the application of the ICNIRP guidelines that will have a legal status from 30 April next year. Garry