Radium 226 in Food and Man in Bombay and Kerala State (India)

Data are presented on the 226Ra content of various food samples collected from Bombay city and high background areas of Kerala State in India. The experimental technique consisted in measuring the activity of the gaseous daughter product 222Rn in a ZnS-coated α-scintillation counter. Comparison of data for the samples of these two areas, having wide differences in their background radiation level, shows that the Kerala samples have a 226Ra/g ash content which is, on an average, a factor of five to ten times higher. An exception is the coconut sample which is grown profusely in Kerala State; this does not show a higher concentration of 226Ra in spite of the higher availability of 226Ra in the Kerala State soil.From a tentative model formed for the food habits of the people of these two regions, their 226Ra burden has been estimated. The determination of 226Ra in bones and other organs of the human body indicates that a man from high background areas of Kerala State contains about ten times more of this radioisotope than a Bombay citizen. A value of 0·85 × 10−14g Ra/g ash of bone was found from direct measurements of a single subject from Bombay.