Studies on Intake and Body Fluid Concentrations of Thorium for Subjects Working and Living in Thorium Rich Environment

The blood serum is the fluid medium through which most of the minerals are absorbed into the human body and get metabolized. The concentrations of Th in blood serum is in equilibrium with the content of Th in human body and therefore could reflect its content in the body. The daily intake (ingestion and inhalation) and the corresponding concentration of Th in blood serum of a group of subjects living in the high-background (monazite) area of Kerala State were measured and compared with the daily intake and corresponding blood serum concentrations of Th in three other groups of subjects namely: (1) those living in normal background area, (2) administrative staff working in Thorium Plant but not directly exposed to Th and its compounds, and (3) the occupational workers from Thorium Plant working for a time period in the range15–30 years. The Th concentration in the blood serum of subjects from high background area were found to be only marginally higher in comparison to the similar data from normalbackground area, which indicated that internal exposure due to Th to the subjects living in high background is quite low.