"There is absolutely not one shred of evidence that 5G or for that matter, 4G, has any harmful effect on humans," Mullen said on Tuesday.
"And I realise for those that believe -- like anti-vaccination or even the Flat Earth Society -- it is very hard to change people's opinion."
Mullen pointed to the entire telecommunications industry, as well as governments, conducting research into the area, and said there were no health impacts from the technology.
"If ever there is any indication whatsoever that we and the industry are wrong, you can be 100% sure that we will not only accept the liability, but we will be all over it," he said.
"But as of today, there is absolutely no evidence."
In response to Mullen, the shareholder claimed they were "electrically sensitive", therefore "don't care what your studies may or may not approve, because I feel it".
"I can see you're a very sensitive person and so am I to this issue," Mullen said.
"We will do the right thing I can assure you."
In July, Telstra conducted a test that found the electromagnetic energy levels used in 5G are similar to 3G, 4G, and Wi-Fi.
"In the testing we completed inside apartments and cafes near our 5G Innovation Centre at Southport on the Gold Coast, we measured 5G EME levels consistently under 0.02% of the ARPANSA standard limit -- that is more than 5,000 times below the safety limit put in place by the Australian government body responsible for EME," Telstra principal EME strategy, governance and risk management Mike Wood said at the time.
"In fact, in our apartment testing, we had a room full of network engineers maxing out their devices simultaneously, while still delivering those EME results of more than 1,000 times below safety limits.
"It is also important to note that existing safety standards for EME cover 5G, including children, are conservative and will also include the higher mmWave frequencies to be used in the future."
Speaking earlier in the day, Mullen said Australia would have received 100Mbps broadband for a majority of the population without NBN, and that Telstra is partly to the blame for how it acted prior to the creation of NBN.
At the height of tension between the government and the then Trujillo-led Telstra, the company submitted a non-compliant bid as it was worried about structural separation. The bid resulted in Telstra being booted out of the issued NBN tender at the time.
"It is my view that over the last 10 years private sector competition between strong players such as Telstra, Optus, TPG and others was always going to build 100MB broadband access and speed to the majority of the population of Australia, in an ongoing competitive landscape and at no cost whatsoever to the taxpayer," Mullen said at the AGM on Tuesday.
"Governments could then have decided how much subsidy they were willing to provide the industry to extend this coverage to regional and rural areas where private sector economics were unattractive."
Mullen claimed the cost would have been "a fraction of the cost" of the NBN, but instead, the country has been lumped with a state-owned monopoly that is set to cost AU$50 billion.
"However we got here and Telstra too must bear part of the blame for this due to its recalcitrance in helping government at the time, whether we like it or not the NBN is here to stay," he said.