A semi-continuous study on the toxicity of atmospheric particles using a versatile aerosol concentration enrichment system (VACES): development and field characterization

Abstract. The toxicity of atmospheric particles directly associates to health effects, but its online monitoring has not yet been implemented due to low-concentration toxic components and high measurement detection limit. To solve the detection problem, we extended a versatile aerosol concentration enrichment system (VACES) for toxicity aerosol measurement and firstly used VACES to provide a comparison of toxicity between non-concentrated and concentrated aerosols in ambient air. Through optimizing the technical parameters, the total concentration (number or mass), the concentration of chemical components, and the toxicity were all increased by approximately 7 to 10 times in VACES. In particular, ambient aerosols with toxicity below the detection limit, were detected significantly after concentration. Moreover, comparable enrichment factors and similar trends before and after enrichment in toxicity were observed over time, suggesting that the toxic properties of ambient aerosols do not change in VACES. Whereas, changes in PM2.5 concentrations and their toxicity do not always correlate well, which was probably driven by the combined toxicity effect of chemical components. Thereby, it hints a necessity to further study on the toxicity effects of chemical compositions. All above also imply that VACES could provide technical support for the future measurement of online atmospheric particulate toxicity, which is currently performed at high-concentration environment, long sampling duration, and offline.