SACRAMENTO, Calif. — California Gov. Gavin Newsom on Monday announced a voluntary smartphone tool to alert people of possible coronavirus exposure as cases soar higher, new restrictions are imposed and many people still say they won't heed the pleas to stay home.
The tool — which has been used on a pilot basis on some state university campuses — doesn't track people's identities or locations but uses Bluetooth wireless signals to detect when two phones are within 6 feet (1.8 meters) of each other for at least 15 minutes, officials said.
California's 40 million residents can opt in to the system starting Thursday. When someone who has activated the technology tests positive for the virus, that person will receive a verification code from state health officials that can be used to send an anonymous alert to other users who may have been exposed over the past 14 days.
"The more people that participate in it, the more that opt in, the more effective this program can be," Newsom told reporters. "We are hoping there will be enough to make this meaningful."
The technology comes as coronavirus cases are exploding in California and more than 80% of the state's residents are under orders not to leave their homes for at least the next three weeks except for essential purposes. Sixteen other states, plus Guam and Washington, D.C., have already made available the system co-created by Apple and Google, though most residents of those places aren't using it.
Andrew Noymer, a public health professor at University of California, Irvine, questioned how many residents would opt in due to privacy concerns and the value of the tool if they don't.
He said people may find themselves paralyzed by a flood of information and it isn't clear what they'll do with it — especially if they take a coronavirus test after getting an alert and wind up negative, only to receive another alert.
"In a purely epidemiological perspective, uptake is everything. If about 10% of people do it, it's useless," he said. "Even if it does get takers, it's still unproven. Because then, what do you do?"