Hazards and analysis of thallium—A review

The most important sources of thallium pollution are gaseous emission from cement factories, coal burning power plants and metal smelters. Inhalation and consumption of home‐grown vegetables and fruits are the major routes of thallium intake. Absorption occurs in gastro‐intestinal tract followed by ingestion in respiratory tract caused by intratracheal infection. Highest concentration is attained in renal medulls of kidney. The normal dietary intake of adults has been estimated at ∼2 μg/day whereas average excretion of T1 is ∼ 1 μg/day. Thallium is excreted both in animal and men through kidney, intestine and in small parts via hair and milk. The concentration of thallium in urine and hair is taken as an indicator of internal exposure; permissible exposure limit is O.1 mgTl/m3. Once distribution is complete, thallium is slowly mobilized from its intracellular compartment with a total body half life of approximately 30 days. The determination of sub micro and micro‐gram quantities of thallium is described with special reference to the analysis of natural (including biological) materials. Key words: Intoxicationsymptomsacute/chronic poisoninggestationteratogenic Notes For correspondence.