A new study showed that in utero exposure to tributyltin (TBT) causes obesity in three subsequent generations of mice (Chamorro-Garcia et al. 2013). Researchers from the University of California investigated the effects of in utero exposure to low doses of TBT.
TBT is not intentionally added to food packaging. In the US mono- and dibutyltins are used in food contact materials, as well as certain other diorganotins. In the EU only dioctyltins are authorized for use in plastics, but dibutyltins may be used in silicones or other food contact materials. TBT may be an impurity of mono- and dibutyltins, and therefore present in food contact materials as so called non-intentionally added substance (NIAS) (Annex 1, ESCO working group report)
The mice exposed to TBT in the study showed increased fat accumulation. Not only the generation of female mice exposed in utero, but also the two subsequent generations showed to have increased white adipose tissue, reprogrammed mesenchymal stem cells, the precursor cells of adipocytes, and increased hepatic fat accumulation. The researchers expressed particular concern regarding the persistence of these effects across generations.
corrigendum March 18, 2013: TBT is currently authorized as indirect food additive (tributyltin chloride, CAS 1461-22-9; tributyl tin oxide, CAS 56-36-0) by the US Food and Drug Administration (FDA) and is used for example as preservative in food packaging adhesive (21 CFR 175.105).
Chamorro-Garcia et al. “Transgenerational inheritance of increased fat depot size, stem cell reprogramming, and hepatic steatosis elicited by prenatal obsogen”. Env Health Perspect (published online January 15, 2013). doi:10.1289/ehp.1205701