Measurement of Background Radiation in Lakes

Abstract

Measurements of background radiation were made in five lakes–two Wisconsin, two New Hampshire, and one antarctic. These lakes were characterized by a small amount of ionizing radiation in mid—water and increasing quantities near the air and sediment boundaries. Moreover, the radioactivity of the sediments in the Wisconsin and New Hampshire lakes usually increased toward the shore line. Count—rate values for the sediments near the shore line were up to ten times higher than the values recorded near the bottom in deep water. A similar pattern of radioactivity distribution in the sediments was not apparent in Lake Vanda, a perennially ice—covered antarctic lake. Various hypotheses were suggested to explain the origin of the anomalous distribution of ionizing radiation in these lakes and its possible role as an environmental factor.

Effects of a variable sun at the beginning of the Cenozoic era

“…That such an environment can be deadly is particularly true of shallow-marine areas, as organisms in or near sublittoral sediments would receive more radiation, would undergo more frequent genetic changes than organisms in deeper parts of the water body (Likens, 1965). In this century, the episodic spread of equatorial warm surface waters along the Pacific coast of Latin America precipitates each time a sizeable decrease in phyto-and zooplankton; temperature-sensitive fish then migrate to deeper, cooler waters (Caviedes, 1975).…”