As of 1940 the US safe standard is 0.05 mg/L or about 50 parts per billion. It was updated in 2006 to 0.01 mg/L or 10 ppb. Their article is off by a little.
The great thing about Art it is Subjective. Hell, I don't care for it either, but someone does. It's their nickel. We not paying, we are not the audience. Most Art is way over my head.
Think about navigating on a bike. It would be cool to have this built into a pair of sunglasses. Maybe even a Heads Up Display with a map,speed, etc. I usually stop and look at the map every so often.
Its not technically a monopoly. Its vertical integration, where they own from the top to the bottom. I'll keep my $15 sunglasses I bought at Walmart in Canada 9 years ago.