When IV solutions are used, particulate matter may be introduced into the patient. Using X-ray studies we could demonstrate particulate matter consisting mainly of glass from ampules, rubber from rubber stoppers of infusion bottles, and plastic material from IV sets. With a recently introduced method of back-scatter pictures in scanning electron microscopy combined with X-ray studies--Jeol 35 CF/EEDS II Ortec (REM EDX)--we analyzed this phenomenon using an animal model (rabbit). It appears that particulate matter is deposited in the interstitial lung tissue and especially the pulmonary microcirculation. Pathogenetic effects could also be demonstrated (formation of thrombi, etc.).