Radioactivity: alpha decay
Purified thorium metal is pyrophoric and can burn or explode.
Natural exposures:
(1) inhalation
(2) ingestion
People at potential risk:
(1) worker at nuclear power plant
(2) person living near nuclear waste site or a natural thorium deposit
(3) miner
(4) industrial worker
(5) person living near weapon testing range
(6) waste disposal workers
Natural thorium is poorly soluble so absorption from the GI tract is poor. Some thorium compounds such as thorium citrate are more soluble.
Adverse effects tend to appear years after the exposure.
Thorium:
(1) accumulates in the skeleton
(2) can result in a dermatitis
(3) may be linked to birth defects
(4) are associated with development of cancer (lung, leukemia, other)
