Oxidative stress and inflammation before and after acrolein exposure in individuals with building related symptoms

Air pollution contributes to both acute and chronic health effects, and since people spend most of their time indoors, exposure to pollutants largely occurs in indoor environments. Acrolein, a reactive aldehyde commonly present indoors, may induce oxidative stress and inflammation and is implicated in asthma and cardiovascular disease. This study examined the impact of controlled acrolein exposure on oxidative stress and inflammatory markers in individuals with and without Building-related symptoms (BRS). Thirty-five participants (21 with BRS, 14 controls) completed two randomized, single blind, crossover sessions in an exposure chamber: (1) acrolein (0.05 mg/m3) mixed with heptane and (2) control exposure with heptane only. Each session lasted 80 min. Plasma and nasal mucosa samples were collected before and after each exposure to assess oxidative stress (glutathione levels, GSH/GSSG ratio) and inflammation (oxylipins, endocannabinoids). No significant overall group effects were observed after acrolein exposure. However, BRS participants showed a significantly lower normalized acrolein-induced change in GSH/GSSG ratio (relative to sham) compared to controls, indicating increased oxidative stress. They also had lower baseline plasma levels of COX- and LOX derived oxylipins, suggesting altered inflammatory profiles. No exposure-related changes in oxylipins or endocannabinoids were detected in either group. These findings suggest that individuals with BRS may have a reduced ability to maintain redox balance when exposed to acrolein, despite having similar baseline GSH/GSSG levels as controls, potentially increasing susceptibility to oxidative stress even at low-levels. Oxidative stress markers could serve as objective indicators of BRS, warranting further research on individual susceptibility and combined effects of indoor pollutants.