formula: Tl; CAS Registry Number: 7440-28-0

Rare element which occurs naturally as trace element in many minerals

It is of limited commercial importance. Thallium is used e.g. in metal working industry, in the production of special-purpose glass and in measuring technology. Thallium sulfate is highly toxic and used as rodenticide and insecticide. It is banned, however, in many countries, e.g. Germany, Switzerland and the USA.

Thallium is released into the environment during weathering of rocks and anthropogenic activities. Water contaminations are mostly caused by industrial waste waters and atmospheric deposition. In aquatic ecosystems, thallium is bioavailable and quickly accumulated by organisms.
Through plants and animals thallium may enter the human food chain.

Environmentally relevant characteristics of thallium and its compounds include:



  • Bioindicator in rivers and lakes
  • Fine insoluble mineral or organic particles in the water phase
  • Common brown alga of the coastal areas of the North and Baltic Sea
  • A major primary producer in semi-natural and anthropogenic affected ecosystems.
  • A major primary producer in semi-natural and anthropogenic affected ecosystems.
  • A deciduous tree typical of ecosystems close to dense conurbations and an indicator for the characterisation of the immission situation during the vegetation period.
  • As the most dominant deciduous tree species in Central Europe, it plays a significant role in most nearly natural and also anthropogenically influenced forest ecosystems up to an altitude of 1100 m.
  • Student groups with an even number of female and male students at the age of 20 to 29.

Sampling area

Sampling period

1985 - 2022

Extended information

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