BREAST-MILK CONTAMINATION AND SILICONE IMPLANTS - PRELIMINARY-RESULTSUSING SILICON AS A PROXY MEASUREMENT FOR SILICONE

In response to concerns about contamination of human breast milk from silicone gel-filled breast implants, and because silicon levels are as sumed to be a proxy measurement for silicone, we compared silicon leve ls in milk from lactating women with and without implants. Two other s ources of infant nutrition, cow's milk and infant formulas, were also analyzed for silicon. The survey took place at the Breast-feeding Clin ic at Women's College Hospital in Toronto. A convenience sample of lac tating women, 15 with bilateral silicone gel-filled implants and 34 wi th no implants, was selected. Women with foam-covered or saline implan ts or with medically related silicone exposures were ineligible. Colle ction of samples was scrupulously controlled to avoid contamination. S amples were prepared in a class 100 ''ultraclean'' laboratory and anal yzed using graphite furnace atomic absorption spectrophotometry. Silic on levels were analyzed in breast milk, whole blood, cow's milk, and 2 6 brands of infant formulas. Comparing implanted women to controls, me an silicon levels were not significantly different in breast milk (55. 45 +/- 35 and 51.05 +/- 31 ng/ml, respectively) or in blood (79.29 +/- 87 and 103.76 +/- 112 ng/ml, respectively). Mean silicon level measur ed in store-bought cow's milk was 708.94 ng/ml, and that for 26 brands of commercially available infant formula was 4402.5 ng/ml (ng/ml part s per billion). We concluded that lactating women with silicone implan ts are similar to control women with respect to levels of silicon in t heir breast milk and blood. Silicon levels are 10 times higher in cow' s milk and even higher in infant formulas.