Air Quality Modelling and Source Apportionment Studies for Aerosols in Switzerland

Size-Resolved Endotoxin and Oxidative Potential of Ambient Particles in Beijing and Zürich

“…It is noted that DTT can react with several kinds of compounds, such as metals and quinones, etc. , In the typical PM 2.5 samples, Charrier et al found that approximately 80% of DTT loss was due to transition metals, especially Cu and Mn, and approximately 20% of DTT loss was due to quinones . Chemical composition analysis showed that the predominant components of the PM 2.5 in Beijing were inorganic ions (NH 4 + , NO 3 – , and SO 4 2– ) and black carbon, which have very small contribution to the DTT test. , Whereas, organic aerosols dominate the aerosol composition in the Swiss summer and they are mainly secondary aerosols with high oxidant generation activity. ,,, The sampling site of PKU (CN-urban campus) was on the campus of Peking University, which is away from traffic, while the sampling site of Zhongguancun North Street (CN-urban main street) is a main street with heavy traffic in Beijing (see Figure S1). Accordingly, the CN-urban main street samples had higher PM concentration than the CN-urban campus samples in the size range of 1–10 μm (see Figure and Figure S2).…”

“…Both endotoxin and heavy metals were important components of PM 1 fraction, which can deposit in alveoli, thus causing a potential health effect. In the present work, we focused more on deposition of endotoxin in alveoli as the deposition of heavy metals was already studied previously. − …”

“…39,57 Whereas, organic aerosols dominate the aerosol composition in the Swiss summer and they are mainly secondary aerosols with high oxidant generation activity. 39,44,57,58 The sampling site of PKU (CNurban campus) was on the campus of Peking University, which is away from traffic, while the sampling site of Zhongguancun North Street (CN-urban main street) is a main street with heavy traffic in Beijing (see Figure S1). Accordingly, the CNurban main street samples had higher PM concentration than the CN-urban campus samples in the size range of 1−10 μm (see Figure 1 and Figure S2).…”