Use of hair testing in thallium poisoning:
(1) initial diagnosis
(2) determination of severity of the exposure
(3) determination of temporal features of the exposure
The presence of certain findings during microscopic examination of the hair root under polarized light can suggest the diagnosis of thallium poisoning:
(1) dystrophic anagen hairs
(2) anagen hairs with dark bands (caused by empty spaces in the disorganized cortex)
Chemical analysis of the hair can be performed:
(1) on the hair as a whole
(2) upon segments, covering different time periods of growth
The amount of thallium in the entire hair can give an indication of the total exposure within the time period represented by the hair growth.
Variation in thallium levels in different segments of hair can delineate variation in exposures.
