A contact-tracing "beacon" app that's been in development since the spring is now rolling out for all Californians, but what does it really do and will it really help anyone find out if they've been exposed to the coronavirus?
We learned back in May that Apple and Google were co-developing software that was capable of detecting, through Bluetooth radio waves, when a cellphone user has been within six feet of someone who testing COVID-positive for 15 minutes or more. The app then provides "exposure alerts" to anyone potentially exposed, so that they can act accordingly.
The California-specific app, called CA Notify, is now available for download. But as experts said when it was first announced, it's only going to be effective if there is widespread adoption — and only if everyone is carrying an Apple or Android phone. And only if they tell the app when they test positive.
That's a lot of ifs, and at this stage in the pandemic when it seems like everyone is tired of following even the simplest rules like keeping a mask over their nose, do we really expect a critical mass of California's 39.5 million residents to download this thing and use it properly if and when they test positive? The app functions anonymously, so you won't be told who infected you, but skepticism about privacy is bound to be an issue as well — and even San Mateo County Health Officer Dr. Scott Morrow expressed some doubts on Monday about how absolutely anonymous cellphone mobility data has been.
There's also the issue that the app isn't likely to distinguish between when you've been six feet from someone on a bus, and when you've been separated by a hotel room wall, for instance.
As Governor Gavin Newsom said on Monday in conjunction with the announcement of the app, he didn't want to "overstate" the potential effectiveness of the app. "This holds a lot of promise,” he said. "The more people that participate in it, the more that opt in, the more effective this program can be."
University of California campuses are using the technology on a pilot basis to try to track cases, but otherwise it does not seem to getting adopted widely. As the Associated Press reports, besides California, 16 other states as well as Guam and the District of Columbia have offered these notification apps based on the same software, but "most residents of those places aren't using it."
If, say, you must go to an essential workplace and you can get everyone else in that workplace to use the app, and get everyone in their families to do it too, then maybe it could be of some use.
Otherwise, just hunker down and assume everyone is contagious.