sean: at his lab at wollongong university, rodney croft runs tests on the effects of radio frequency simulating the radiation emitted by mobile phones. rodney: what we're really doing is setting people up, putting electrodes on their head, looking at the brain activity, the electrical activity caused by the brain, and whether it's being influenced by the mobile phones. when we started, we were looking for large changes in the brain, thinking it could be a real problem, but we just don't find those. we don't see any changes in brain cancer, which is something that we often hear activists complain about. and, well, there's probably thousands of claims out there, and none of them have actually bore any fruit in terms of being able to demonstrate that there is an adverse heal effect due to mobile phone usage. sean: some people also say that, particularly with 5g millimeter wave technology, there is concern because it will mean more antennas all over the place, and therefore more radiation out in the atmosphere that we will be exposed to. what do you think about that claim? rodney: so far,