Sure you can't compare the technology nor the numbers of users. The power of radio-waves is lower today than in the seventies but everyone uses the technology so it'd be interesting to see some maths of constant environment radiation. If you live in an urban environment it's not as simple as putting your phone down as you're swimming in a sea of radiation from everyone else.

Also Cisco are in the business of selling telecoms devices. It's like the tobacco industry assuring us that smoking cigarettes in moderation is not harmful. At some point even doctors recommend smoking! The truth of health impact of tech always lags well behind the greed to profit from it as much as possible at any cost.