 Scientific literature concurs that bismuth and most of its compounds are less toxic compared to other heavy metals ( lead , antimony , etc . ) and that it is not bioaccumulative . They have low solubilities in the blood , are easily removed with urine , and showed no carcinogenic , mutagenic or teratogenic effects in long @-@ term tests on animals ( up to 2 years ) . Its biological half @-@ life for whole @-@ body retention is 5 days but it can remain in the kidney for years in patients treated with bismuth compounds . 
