“Brave New World” by Huxley had the same concept back in the 20’s.
Hubby and I used to watch a t.v. show called "Fringe". The "Fringe" is a reference to "fringe" science. Anyway, they had an episode where a former Nazi was using an aerosol to kill certain ethnic groups. He performed a test where he killed everyone in a cafe who had brown eyes.
That this sort of thing is something the ChiComs are actually working on is very scary.