Fig. 3From: Airway and systemic biomarkers of health effects after short-term exposure to indoor ultrafine particles from cooking and candles – A randomized controlled double-blind crossover study among mild asthmatic subjectsScanning Electron Microscope (SEM) images of filters from exposures sessions. Legend: a) a cooking exposure, b) a candle exposure and c) an unused reference filter. From b) candle particles and agglomerates down to 20 nm can be observedBack to article page