Letter re: "Cyclosiloxanes produce fatal liver and lung damage in mice".

with 'H nuclear magnetic resonance (NMR) technique using an internal control (5). Blood samples from animals given feed without siloxanes showed no signals originating from the silicones tested. In all blood samples from animals given feed with siloxanes, they were detected. In samples from animals given feed with PDMS, the mean concentration (± standard deviation) of siloxanes of 26 ± 14 pg/cm3 was noted; in samples from animals given feed with cPDMS, the mean concentration of siloxanes of 70 ± 97 pg/cm3 was noted. The difference was not significant. These results conform well to those obtained previously in Rhesus monkeys by Calandra et al. (6). In our opinion, the absorption and toxicity of siloxane-based drugs should be more intensively studied. Our study was supported by the Polish State Committee for Scientific Research (KBN) (grant 4P05D06612).