"Since then there have been added at least 1,000 Bq/m^3 of man-made Potassium-40 which is not part of natural potassium"
has been quoted several times at ENE, with the implication that man has added 1000 Bq/M3 to the ocean.
PT had stated 11,000Bq/M3 from a 1971 source. And then later I calculated 11,800 or round to 12,000
So out of that became the "1000 bq/m3 of man-made Potassium-40" added
Let's trace the original information
Going to the source document (which is embedded in this post at the far bottom)
unusual convention dpm/minute. K40 decays 90% as a beta, 10% as a gamma. And Geiger counters are not of perfect efficiency, i.e. they don't catch every disintegration. Wait for the punchline, but review this first.
By knowing the "Specific Activity" of K-40 it is then simple to calculate the Bq/Liter, or Bq/M3
Which is used in my calculation, its one of the blue shaded values above.
So rather than using the scientific specific activity, they used a field measured dpm, and that is the error. So if their Geiger was 93% efficient, then the 670 dpm, you would add 7% to bring the low efficiency measurement up to the real Bq/min or 717 and then divide that by 60 seconds to arrive at 11.94 Bq/L, and then convert that to M3
11, 940 Bq/M3 Now that is More Like Reality
So all this misunderstanding and "creation of human generated K-40" was simply due to a non perfect Geiger Counter, and an author who choose to round down to 11,000 even.