We've witnessed an explosion in the use of wireless devices, from about 100,000 in Canada in 1986 to over 17 million today. If you look at some European countries, the market penetration is over 100%, which means that some people own more than one cellular phone, and on average everybody has at least one. So your observation of people making more use of this technology is quite accurate.
You could express some concerns about the larger number of people using the technology, the longer amount of time they're on the phone increasing their exposure to RF fields. If there is a risk, we are looking at larger numbers of people exposed.
Having looked at just about every piece of scientific data that's ever been accrued on this topic, at this point—and there have been over 40 epidemiologic studies of radio frequency fields on health—we have no clear evidence of an association between radio frequency fields and adverse health outcomes.
As I mentioned in my opening remarks, there are some subtle biological changes, things like alterations to the rate at which certain ions get transported across cellular membranes, which have no known clinical significance, but probably warrant a little bit of investigation. That's the reason we have embarked on additional research studies, to my mind the most important of which is the World Health Organization's 13-country study, which will be looking at long-term heavy users of cellular telephones as one of the population subgroups. When our results become available later this year, I think we'll be able to give you some direct scientific, factual information on your question.