[Hair as a study object in case of poisoning with heavy metal salts].

The objective of the present work was to analyse the results of morphological studies of hair taken from the children with suspected thallium poisoning. The findings obtained by isoelectrofocusing, spectroscopy, and scanning electron microscopy were compared with the relevant literature data. Original investigations included a comparative microstructural study along the hair length and cross section. We failed to observe formation of black-purple structures in the hair bulb and root region of the shaft usually associated with thallium poisoning. It is concluded that thallium poisoning can not be diagnosed based on the presence of a black pigment, knob-like swellings, and spindle-shaped bulbs since they are normal elements of healthy hair. More sensitive methods for the determination of trace elements and their combination with morphological investigations are needed for the definitive diagnosis of thallium poisoning.