December 12th, 2017
ABSTRACT Background: Polyvinyl chloride (PVC) materials have been linked to asthma in several epidemiological studies but the possible causal factors remain unknown. Participants: We challenged ten subjects experimentally to degraded PVC products under controlled conditions.All subjects had previously experienced respiratory symptoms suspected to be due to this kind of exposure in their work place. Five subjects had doctor-diagnosed asthma. Methods: The subjects were exposed to degraded PVC material in an exposure chamber with ceramic tile challenge being used as the control test. Exhaled nitric oxide (NO), nasal NO, lung functions, cytokines (TNF-?, IL-4, IL-6 and IL-12) and NO in nasal lavage fluid (NAL) were followed during and after the exposures. We also measured 2-ethylhexanol in exhaled breath samples and NAL. Results: On the morning after the PVC exposure, the subjects reported significantly more often respiratory tract symptoms compared to symptoms reported after the control test (50% vs. 0%, respectively, p=0.029, n=10). We did not detect any changes in lung functions or levels of exhaled NO, nasal NO or NO in NAL after PVC challenge compared to the control test. Cytokine levels increased after both exposures with no statistically significant difference between situations.All of the exhaled breath samples collected during the PVC exposure contained 2-ethylhexanol. Conclusions: PVC flooring challenge can evoke respiratory tract symptoms in exposed subjects. Our results do not support the proposal that PVC materials themselves evoke immediate asthmatic reactions. The chamber test developed is well suited to this kinds of exposure studies.