A review concerning organosilicon compds. in the environment is given. Topics discussed include: polydimethylsiloxanes (PDMS); volatile methylsiloxanes (VMS); silanols; anal. procedures and methods (PDMS, VMS, and silanols analyses in environmental samples by gas chromatog., environmental sample anal. by HPLC, biol. sample anal.); environmental concns. and processes (PDMS in soil, sediment, and waste; VMS in air, soil, sediment, and waste; silicone persistence in the environment: PDMS, VMS, silanols; transfer of alkyl groups to other species); interactions with organisms (colonization, degrdn., and transport of silicones in organisms, toxicol. and immunol. of silicones, silicone breast implants, Si and silicones in body fluids and tissues); and summary and outlook.