Studies revealed airports as a prominent source of ultrafine particles (UFP), which can disperse downwind to residential areas, raising health concerns. To expand our understanding of how air traffic-related emissions influence total particle number concentration (PNC) in the airport’s surrounding areas, we conduct long-term assessment of airborne particulate exposure before and after relocation of air traffic from “Otto Lilienthal” Airport (TXL) to Berlin Brandenburg Airport “Willy Brandt” (BER) in Berlin, Germany. Here, we provide insights into the spatial–temporal variability of PNC measured in 16 schools recruited for Berlin-Brandenburg Air Study (BEAR).
The results show that the average PNC in Berlin was 7900 ± 7000 cm−3, consistent with other European cities. The highest median PNC was recorded in spring (6700 cm−3) and the lowest in winter (5100 cm−3). PNC showed a bi-modal increase during morning and evening hours at most measurement sites due to road-traffic emissions. A comparison between measurements at the schools and fixed monitoring sites revealed good agreement at distances up to 5 km. A noticeable decline in this agreement occurred as the distance between measurement sites increased. After TXL was closed, PNC in surrounding areas decreased by 30 %. The opposite trend was not seen after BER was re-opened after the COVID-lock-down, as the air traffic has not reached the full capacity yet. The analysis of particle number size distribution data showed that UFP number fraction exhibit seasonal variations, with higher values in spring and autumn. This can be explained by nucleation events, which notably affected PNC.
The presented findings will play a pivotal role in forthcoming source attribution and epidemiological investigations, offering a holistic understanding of airports’ impact on airborne pollutant levels and their health implications. The study calls for further investigations of air-traffic-related physical–chemical pollutant properties in areas found further away (> 10 km) from airports.
The German Ultrafine Aerosol Network (GUAN) is a cooperative effort to scientifically explore the health and climate-related properties of the atmospheric aerosol in Germany. This work presents results on the basis of long-term observations of particle number size distributions and equivalent black carbon (eBC) between 2009 and 2014. At 17 observation sites, we found variations in mean total par ticle number concentration (diameter range 20 to 800 nm) between 850 and 10,500 p. cm-³, and in eBC mass concentration between 0.17 and 2.8 mg m-³. Time series trend analyses yielded a significant relative decrease in eBC mass concentration (median: -5%/year) and in total particle number concentration (median: -4%/year), which is rather consistent at almost all sites over Germany. The consistent downward trends suggest that air quality-related societal efforts, which have been targeted mainly at reductions of total particle mass emissions, have a beneficial effect on ambient total particle number, ultrafine particle number, and eBC mass concentrations as well.
Size-fractioned particulate air pollution and cardiovascular emergency room visits in Beijing, China
(2013)
Background
Although short-term exposure to ambient particulate matter has increasingly been linked with cardiovascular diseases, it is not quite clear how physical characteristics of particles, such as particle size may be responsible for the association. This study aimed at investigating whether daily changes in number or mass concentrations of accurately size-segregated particles in the range of 3 nm–10 μm are associated with daily cardiovascular emergency room visits in Beijing, China.
Methods
Cardiovascular emergency room visit counts, particle size distribution data, and meteorological data were collected from Mar. 2004 to Dec. 2006. Particle size distribution data was used to calculate particle number concentration in different size fractions, which were then converted to particle mass concentration assuming spherical particles. We applied a time-series analysis approach. We evaluated lagged associations between cardiovascular emergency room visits and particulate number and mass concentration using distributed lag non-linear models up to lag 10. We calculated percentage changes of cardiovascular emergency room visits, together with 95% confidence intervals (CI), in association with an interquartile range (IQR, difference between the third and first quartile) increase of 11-day or 2-day moving average number or mass concentration of particulate matter within each size fraction, assuming linear effects. We put interaction terms between season and 11-day or 2-day average particulate concentration in the models to estimate the modification of the particle effects by season.
Results
We observed delayed associations between number concentration of ultrafine particles and cardiovascular emergency room visits, mainly from lag 4 to lag 10, mostly contributed by 10–30 nm and 30–50 nm particles. An IQR (9040 cm−3) increase in 11-day average number concentration of ultrafine particles was associated with a 7.2% (1.1–13.7%) increase in total, and a 7.9% (0.5–15.9%) increase in severe cardiovascular emergency room visits. The delayed effects of particulate mass concentration were small. Regarding immediate effects, 2-day average number concentration of Aitken mode (30–100 nm) particles had strongest effects. An IQR (2269 cm−3) increase in 2-day average number concentration of 30–50 nm particles led to a 2.4% (−1.5–6.5%) increase in total, and a 1.7% (−2.9–6.5%) increase in severe cardiovascular emergency room visits. The immediate effects of mass concentration came mainly from 1000–2500 nm particles. An IQR (11.7 μg m−3) increase in 2-day average mass concentration of 1000–2500 nm particles led to an around 2.4% (0.4–4.4%) increase in total, and a 1.7% (−0.8–4.2%) increase in severe cardiovascular emergency room visits. The lagged effect curves of number and mass concentrations of 100–300 nm particles or 300–1000 nm particles were quite similar, indicating that using particulate number or mass concentrations seemed not to affect the cardiovascular effect (of particles within one size fraction). The effects of number concentration of ultrafine particles, sub-micrometer particles (3–1000 nm) and 10–30 nm particles were substantially higher in winter comparing with in summer.
Conclusions
Elevated concentration levels of sub-micrometer particles were associated with increased cardiovascular morbidity. Ultrafine particles showed delayed effects, while accumulation mode (100–1000 nm) particles showed immediate effects. Using number or mass concentrations did not affect the particle effects.
In this paper, we investigate physico-chemical properties of particulate matter (PM) at an urban mixed site (UB) and two roadside (RS) sites during the 2015 Metro Manila Aerosol Characterization Experiment (MACE). Aerosol particle number size distributions (0.01–10 μm diameter) were measured using a combination of a mobility particle size spectrometer and aerodynamic particle size spectrometers. PM2.5 filter samples were analyzed for total mass, organic carbon (OC), elemental carbon (EC), water-soluble inorganic ions, and elemental species. Mass closure between the gravimetric mass, chemical composition, and mass concentration derived from the number size distribution was performed. We found that the bulk PM2.5 mass was dominated by carbonaceous materials, followed by secondary inorganic aerosols and crustal matter at all sites. The average OC/EC ratios at the RS sites (0.16–1.15) suggest that a major fraction of the aerosol mass at these sites derives from traffic sources, while the OC/EC ratio at the UB site (2.92) is indicative of a more aged aerosol, consistent with greater contribution from secondary organic carbon (SOC) formation. The ultrafine particles (UFPs, diameter < 100 nm) dominated (89–95%) the total particle number concentration at the three sites, highlighting the importance of such measurements in this region. However, UFPs have low mass contribution to PM2.5 (7–18%), while particles in the accumulation mode (diameter 100–1000 nm) accounted for most of the number-derived PM2.5 mass concentration (61–67%). On average, strong agreement between the chemically-derived mass and the gravimetric mass was found (slope = 1.02; r2 = 0.94). The number-derived mass concentration correlated well with the gravimetric PM2.5 mass (slope = 1.06; r2 = 0.81). These results highlight the need for more comprehensive PM characterization, particularly focusing on size-resolved chemical composition and particle number size distributions. The mass closure approach presented in this work provides a framework for a conversion between number size distributions and PM2.5 mass concentration in real time in an environment with similar characteristics.
