Excessive x-rays in pre-1968 TVs

The master makes the comment that “Prior to 1968 or so some [TV] sets emitted excessive X-rays, but that problem has now been eliminated.” (http://www.straightdope.com/classics/a920724.html, repeated as http://www.straightdope.com/classics/a5_105.html).

What does “some” mean? What does “excessive” mean? How would an hour’s TV watching compare in exposure to, say, a dental x-ray?

Bolding is mine.

From http://www.fda.gov/cdrh/consumer/TVRad.html

So I doubt that it was significant, but this will get things started.

Bolding is mine.

From http://www.fda.gov/cdrh/consumer/TVRad.html

So I doubt that it was significant, but this will get things started.

The source provided by samclem (http://www.fda.gov/cdrh/consumer/TVRad.html) states that the current standard (mandatory in the US from June 1, 1971) was 0.5 milliRoentgen/hour; but it doesn’t state how far away from the set this is measured (important due to inverse-square law) or what the situation was prior to 1968.

But we’re on the right track.