The effect of this has been to almost double the amount of C14 activity in terrestrial carbon bearing materials (Taylor, 1987).
De Vries (1958) was the first person to identify this 'Atom Bomb' effect.
Thus, it dilutes the activity of the lake meaning that the radioactivity is depleted in comparison to 14C activity elsewhere.
The lake, in this case, has a different radiocarbon reservoir than that of the majority of the radiocarbon in the biosphere and therefore an accurate radiocarbon age requires that a correction be made to account for it.
In the northern hemisphere the amount of artificial carbon in the atmosphere reached a peak in 1963 (in the southern hemisphere around 1965) at about 100% above normal levels.
Since that time the amount has declined owing to exchange and dispersal of C14 into the Earth's carbon cycle system.
Hans Suess (1955) discovered the industrial effect (also called after him) in the 1950's.
A number of researchers found that the activity they expected from material growing since 1890 AD was lower.
Since about 1890, the use of industrial and fossil fuels has resulted in large amounts of CO2 being emitted into the atmosphere.
Since about 1955, thermonuclear tests have added considerably to the C14 atmospheric reservoir.
This C14 is 'artificial' or 'bomb' C14, produced because nuclear bombs produce a huge thermal neutron flux.
In such a case, it is very difficult to ascertain the precise reservoir difference and hence apply a correction to the measured radiocarbon age.
Spurious radiocarbon dates caused by volcanic emanations of radiocarbon-depleted CO2 probably also come under the category of reservoir corrections.