Trends of PM2.5 and Chemical Composition in Beijing, 2000-2015

The concentrations of PM 2.5 and trace elements with hourly resolution were measured during May 2014 in urban residential area of Wuhan, the biggest city in central China. During the period of measurement, the average temperature was approximate 25°C without domestic heating and cooling. The average concentration of PM 2.5 was 95.53 µg m -3 , which was higher than the limit of Ambient Air Quality Standard of China GB3095-2012 (75 µg m -3 , Level 2). A sand storm original from Northwestern China was also recorded. Concentrations of major trace elements (K, Ca, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Pd, Ag, Cd, Au, Hg, Pb, Co, Sn, Sb, Tl) were comparable to previous studies, except for Ba and Ca with more than doubled concentrations (103 ng m -3 , 1,792.49 ng m -3 ) due to the storm. Enrichment Factor (EF) and Positive Matrix Factorization (PMF) were employed to characterize the emission sources. The computation of EF showed that Zincs was highly enriched. Four sources, biomass burning (63.2%) might mainly related to power plants using biowaste burning and bio-related cooking activities, metallurgical and steel industries (14%), dust crustal (12.5%) and dust associated with vehicular traffic (10.4%), were identified in decreasing order of average percentage contribution to the PM 2.5 mass with the aid of trace elements. The orientations of emission sources were also addressed.

Section: Introductionmentioning

confidence: 99%

Characteristics and Source Analysis of Trace Elements in PM2.5 in the Urban Atmosphere of Wuhan in Spring

Acciai

Zhang

Wang

et al. 2017

“…Beijing, an international megacity, has been suffering from serious PM 2.5 (aerosol particles with an aerodynamic diameter of ≤ 2.5 µm) pollution (Xu et al, 2005;Zhou et al, 2015;Lang et al, 2017). Although previous studies have shown that the annual average concentration of PM 2.5 in some cities in China was more than 90 µg m -3 (He et al, 2001;Zheng et al, 2005;Meng et al, 2007;Feng et al, 2009), public awareness regarding PM 2.5 was low until 2011.…”

Section: Introductionmentioning

confidence: 97%

Variation of Bacterial and Fungal Community Structures in PM2.5 Collected during the 2014 APEC Summit Periods

Lù

et al. 2018

The biological fraction of PM 2.5 is considered to be a major cause of various allergies and respiratory diseases. Nonetheless, differences in bacterial and fungal communities in PM 2.5 under different air quality conditions are not well known. In the present study, we collected PM 2.5 samples from October 15, 2014 to November 12, 2014 when several successive "AsiaPacific Economic Cooperation (APEC) blue" days were recorded, following the implementation of strict emission control measures to ensure the APEC summit held during November 5-11, 2014 in Beijing. This study analyzed bacteria and fungi in PM 2.5 samples through rRNA gene high-throughput sequencing. In total, 690 genera of bacteria and 229 genera of fungi were detected. The variations of species richness and community diversity of bacteria and fungi in PM 2.5 were not affected significantly by the emission control measures adopted during the summit and different air quality levels. The bacterial and fungal community structures in PM 2.5 collected during the summit exhibited over 83.7% and 79.6% similarities respectively, with PM 2.5 collected from air graded as "good" quality (AQI ≤ 100) before the APEC summit. Bacteria and fungi in PM 2.5 samples collected at AQI levels between 101-200 and 201-300 before the APEC summit had more than 73.4% and 76.3% community structure similarity, respectively, with PM 2.5 samples collected at AQI ≤ 100. The difference between day and night PM 2.5 samples was very small for bacterial and fungal community structures. Furthermore, most of the inhalable bacteria and fungi were nonpathogenic and no a clear relationship between air quality levels and pathogens was observed. Our results showed that bacteria and fungi in PM 2.5 were less affected by emission control measures and different air quality levels. However, due to the limited number of samples, the relationship between air pollution levels and airborne bacteria and fungi still needs further study.

“…Coal combustion is increasing in China and is one of the largest sources of PM 2.5 in Beijing (Huang et al, 2014;Lang et al, 2017). In Kumamoto, no coal combustion source was observed near the sampling site.…”

Section: Seasonal Variation Of Pah and Element Tracer Concentrations mentioning

confidence: 99%

Measurement of Ambient PAHs in Kumamoto: Differentiating Local and Transboundary Air Pollution

Sugiyama

Shimada

Miura

et al. 2017

We developed an index to investigate the effect of transboundary air pollution (TAP) on the air quality of Kumamoto City, Japan. We estimated the effect of TAP by using the index and positive matrix factorization (PMF). Polycyclic aromatic hydrocarbons (PAHs) and trace metals were analyzed from the daily samples of the Total Suspended Particles (TSPs) collected seasonally from Oct. 2014 to Aug. 2015. These chemical components exhibited high concentrations in spring and winter, which is consistent with the data in the literature. Pb was identified as the TAP tracer owing to its high concentrations in winter and spring. Indeno(1, 2, 3-cd)pyrene (IcdP) was used as the local emission tracer in Kumamoto on the basis of previous studies. We applied the IcdP/Pb ratio as the index. The index enables the detection of TAP in daily data sets. PMF identified six factors: soil and road dust, biomass and waste burning, heavy oil combustion, fishing boats, vehicle emission, and coal combustion. The average contribution of TAP on the days when transboundary pollution was high was evaluated as being 46%.