CCMIN090297 - Laserfiche WebLink

Mayor Tarver asked if this was acceptable in his opinion. Mr. Bushberg said in general the biological effects can be generalized through study of other telecommunications bands. While some frequency effects have been identified, none of them have been at such a magnitude to require more research. Mayor Tarver asked his opinion about the cumulative effect of microwaves, mobile radios, and cellular phones. Mr. Bushberg said the cumulative effects could be evaluated by assessing what impact they would have on the energy deposition of the body. In order to determine this, each site would have to be studied as to what effect it has on the surrounding residents. Mayor Tarvet wanted to know if there had been a study done on this. Mr. Bushberg said no, but a study could be done to determine a safe level of exposure. Ms. Michelotti asked how close residents could be before the levels would be unsafe. Mr. Bushberg said both engineering reports spoke to the cumulative effect of all of the carriers operating at their maximum capacity. The levels are still below the safe level. Ms. Dennis asked Mr. Bushberg to clarify the hazard between a pulse from a handset or a steady pulse from the transmission tower and also non-linear effects where the emissions are more hazardous at a lower level. Mr. Bushberg said there is more exposure from headsets than the maximum exposure from towers around residents. The difference is in the way in which the signal is sent from the towers. There are studies done on whether the periodic pulse is more or less significant than a continuous pulse. There are many biological effects from a wide variety of different physical and chemical agents. In regards to the non-linear effect, studies have failed to see any significant effect. Most studies show when the dose was raised the effect was higher. There is some controversy over the studies. Mr. Pico asked what would be the effect of exposure if someone were to climb up on the tower for an extended length of time and how far away would someone have to be before the exposure would be safe. He asked if the radio frequency from the tower was a beam of energy. Mr. Bushberg said if someone were direc~y in front of it with all the channels working the exposure would be much greater than someone who was six to eight feet away. The radio frequency is an emission pattern with the majority of the energy radiated out parallel to the ground at the height of the tower, with a fraction of the energy being emitted off in other directions. Pleasanton City Council 9/2/97 Minutes 15