Acute and Long-Term Effects of Polyvinylchloride (PVC) Smoke on the Respiratory System of the Baboon and a Comparison with the Effects of Hydrogen Chloride (HCl

Abstract

The acute and long-term effects of smoke produced by flaming and nonflaming combustion of PVC were investigated in the baboon and com pared with those produced by HCl. Four groups of three anesthetized adult male baboons (Papio cynocephalus) were exposed for 15 minutes to air (con trols), flaming or nonflaming PVC smoke containing a targeted 5000 ppm con centration of HCl, or to HCl at a targeted concentration of 5000 ppm. The ani mals responded to flaming or nonflaming PVC smoke with an increase in frequency and minute volume, accompanied by decreased arterial pH and PaO₂ and increased PaCO₂ values. Although pulmonary function tests, CO₂ chal lenge tests, or arterial blood gas measurements in PVC smoke-exposed animals showed sporadic differences from controls at 90, 180, or 360 days postexposure, the results did not indicate the development of impaired pulmonary function. These results were consistent with the absence of exposure-related respiratory tract pathology, although an inflammatory cell response was noted in the minor airways of one animal exposed to flaming PVC smoke. The effects of flam ing or nonflaming PVC smoke were generally similar to those of HCl, in dicating that HCl is retained in the upper respiratory tract, even in the pres ence of particulates in smoke.