Metals in tobacco smoke 'mimic oestrogen' in lab tests
Findings from Georgetown University in the US have suggested that certain metals present in tobacco smoke can mimic the effects of oestrogen, the female sex hormone.
Oestrogen is thought to encourage the growth of some breast cancers.
Evidence for a link between breast cancer and smoking is controversial, however, with the majority of studies suggesting, at worst, only a weak link between the two.
The latest study, published in the scientific journal Endocrinology, has shown that ?tobacco smoke condensate? (TSC) - a liquid derived from tobacco smoke - can mimic the action of the female sex hormone, oestrogen, on cells grown in the lab.
The researchers were able to pin down the oestrogenic activity of the tobacco smoke to the portion that contained ?inorganic? (non-carbon-based) chemicals.
Further studies are being conducted to identify exactly which metals cause the effect.
If confirmed, the finding will add yet another carcinogen to the 69 cancer-causing chemicals already identified in tobacco smoke.