In a message dated 6/26/2006 3:16:06 P.M. Eastern Standard Time, [EMAIL PROTECTED] writes:
Actually, it's a first order approximation....not a straw man. First, we know that the rate of cancer caused by the E&M fields within the brain is, at most, the total rate of brain cancer. I think Zimmy's point is that the exposure of the brain to E&M from cell phones is a fraction of the exposure from within the brain itself. Part of this is the absorption in the skull, part of it is the good old fashion inverse square law. Local fields from synapse firing can be seen as strong fields over a very small volume. We know that we can pick up signals from inside the brain through our thick skulls ....with EEGs. Thus, Yes that is it > Is there an increased risk? Maybe. Has it been shown or ruled out? > Not yet. Not ruled out, but a fairly low upper limit has been set. It has to be small enough to not be seen against a relatively low rate of primary brain tumors...7 to 10 per 100k. Further, if you look at penetrating power, these tumors should be relatively shallow....which results in a further lowering of the background....since only a subset of tumors are shallow...Zimmy can give some numbers on this, I'd bet. Primary brain tumors typically arise from the white matter that is not the superficial part of the brain. Some tumors are superficial; benign tumors - meningiomas arise from the linings of the brain. There is an increased incidence of meningiomas in individuals who have been previously irradiated. For instance in the mid 20th century in Europe lice infestations were treated with radiation (really). So we used to see an unusually high number of meningiomas in old polish immigrants. Otherwise I know of no predilection for brain tumor that is not based on the histologic tumor type. (Certain types of cells are more common in different parts of the brain so it is not surprising that the tumors that arise from these cells are common where the cells reside. >Is there a plausible mechanism? Scientists are divided. That's a true statement, but a tad misleading. Proponents of a mechanism need to demonstrate how low levels of RF signals cause cancer, while there is a significant upper limit on higher levels. I remember a similar argument with power lines. My friend, who had worked in RF modeling for over a decade at the time, pointed out that the fields that supposedly cause cancer are significantly smaller than fields that exist at the cellular levels in the body. And, since the energy is non-ionizing, comparison of fields strengths should be valid. Finally, if RF fields cause cancer, shouldn't we see a large increase in cancers caused by the use of NMR machines? _______________________________________________ http://www.mccmedia.com/mailman/listinfo/brin-l
