Occurrence of butyltin compounds in human blood

Residues of butyltin compounds, including mono-,(MBT), di- (DBT) and tributyltins (TBT), were measured in human blood collected from central Michigan,U.S.A. MET, DBT, and TBT were detected in 53, 81, and 70% of the 32 blood samples examined. Concentrations of butyltins were in the order of MBT > DBT greater than or equal to TBT, with total butyltin concentrations ranging from less than the limit of detection to 101 ng/mL. Exposure of humans to butyltin compounds used as stabilizers or as biocides in household articles has been regarded as a source in addition to the ingestion of contaminated foodstuffs, There was no significant difference in concentrations of butyltin compounds between Sexes. Concentrations of butyltin compounds did not exhibit pronounced ae-dependency, which is different from those observed for persistent pollutants such as polychlorinated biphenyls (PCBs). In general, concentrations of butyltins. measured in:blood were less than that affected human natural killer lymphocytes (a primary immune defense against tumor and,virally infected cells). The toxicological significance of the concentrations of butyltins observed in this study is:unknown. However, the potential for sporadic incidences of great exposure and possible synergistic effect on immune function when exposed in mixtures suggest a need for further investigations to evaluate sources and effects of butyltins in humans.