The dose response of arsenic in induced hair of the rat and its relation to the content in various organs following acute exposure.

Induced hair of the rat was used in well-controlled standardized experiments to examine the reliability of hair analysis as an indicator of arsenic ingestion and internal exposure. A clear dose response was established for single doses between 50 micrograms and 5 mg corresponding to doses per kg body weight of 130 micrograms to 13 mg. In the range of high doses this dose response in the rat was about ten times lower than that found in man. The transfer of endogenous arsenic was only observed in growing, not in resting hair. Endogenous arsenic in hair was not removed by mild preanalytical washing. The amount found in hair growing within 10 or 12 days after the single dose or the start of treatments was the same regardless of whether the dose had been administered in one intubation or it had been split into ten treatments. After the very efficient transfer observed for a relatively short time following ingestion of the element, a sharp decrease in As content of the hair was observed despite a persisting load within the major organs.