Assessment of air pollution toxicity in urban environments in Barcelona, Spain, using a mobile air-liquid interface system

Toxicity of airborne particles and gases was analyzed using a mobile air-liquid interface (ALI) exposure system at a busy harbor and an urban background site in Barcelona, Spain. Toxic effects were assessed in human A549 cells exposed directly to urban air by measuring lactate dehydrogenase release. Simultaneously, air quality measurements were conducted to monitor particle and gas concentrations. At both sites, air pollution was highly influenced by transport emissions from marine or terrestrial sources. Partial least squares (PLS) analysis predicted up to 80% of ALI toxicity variance based on air quality parameters. The analysis revealed correlations between air toxicity and both gases and particles representing both primary and secondary air pollutants. Notably, gas phase pollutants, particularly ozone, were the main contributors to the observed toxicity. In addition to demonstrating the effectiveness of the ALI system for in situ assessment of the toxicity of ambient air pollutants, our study emphasizes the importance of combining ALI exposures with air quality measurements to identify the specific components responsible for harmful effects.