Previous studies observed associations between airborne particles and cardio-vascular disease. Questions, however, remain as to which size of the inhalable particles (coarse, fine, or ultrafine) ...exerts the most significant impact on health.
For this retrospective study, data of the total number of 23,741 emergency service calls, registered between February 2002 and January 2003 in the City of Leipzig, were analysed, identifying 5326 as being related to cardiovascular incidences. Simultaneous particle exposure was determined for the particle sizes classes <
100
nm (UFP), <
2.5
μm (PM2.5) and <
10
μm (PM10). We used a time resolution of 1
day for both parameters, emergency calls and exposure.
Within the group of cardiovascular diseases, the diagnostic category of hypertensive crisis showed a significant association with particle exposure. The significant effect on hypertensive crisis was found for particles with a size of <
100
nm in diameter and starting with a lag of 2
days after exposure. No consistent influence could be observed for PM2.5 and PM10. The Odds Ratios on hypertensive crisis were significant for the particle size <
100
nm in diameter from day 2 post exposure OR
=
1.06 (95%CI: 1.02–1.10, p
=
0.002) up to day 7 OR
=
1.05 (95%CI 1.02–1.09, p
=
0.005).
Ultrafine particles affect cardiovascular disease adversely, particularly hypertensive crises. Their effect is significant compared with PM2.5 and PM10. It appears necessary, from a public health point of view, to consider regulating this type of particles using appropriate measurands as particle number.
► Considering for the first time a detailed size distribution of fine and ultrafine particles and their influence on health. ► The number of ultrafine particles is of higher importance for cardiovascular disease than the particle mass of PM2.5 or PM10. ► Health effects start 2
days after exposure.
Two-year measurements of particle number size distribution (3
nm–10
μm) were conducted in Beijing, China since March 2004. Their seasonal, weekly and diurnal variations and dependencies on ...meteorological parameters were investigated. The annual average particle number concentrations of the nucleation mode (3–20
nm), Aitken mode (20–100
nm), and accumulation mode (0.1–1
μm) are 9000
cm
−3, 15,900
cm
−3, and 7800
cm
−3, respectively. Particle number concentrations in Beijing are generally higher than that in cities of developed countries, especially for the accumulation mode particles. Both the highest total particle number concentration and the lowest volume concentration occurred in spring due to the frequent nucleation events. However, the minimum particle number concentration was observed in summer, and the maximum volume concentration in fall. The diurnal variation of the nucleation mode particles was mainly influenced by nucleation events, primarily in spring and winter. The diurnal variation of number concentration of the Aitken mode particles closely correlates with the traffic densities in all the four seasons. At the same time, obvious contribution of the growth of the nucleation mode to the number concentration of the Aitken mode particle has been also found in spring, summer, and fall. Significant differences in diurnal patterns of particle number concentrations between workdays and weekends are not observed in Beijing. Local wind speed plays an important role in shaping the particle number size distributions in the urban area of Beijing. With increasing wind speed, the nucleation and coarse mode particle number concentrations increase, while the number concentrations of the Aitken mode and accumulation mode particles decrease. A “U-shape relationship” between the total particle volume concentration and wind speed is observed. Frequently low wind speed (lower than 3
m s
−1) in Beijing is one of key factors leading to the poor air quality and low visibility.
Properties of atmospheric black carbon (BC) particles were
characterized during a field experiment at a rural background site (Melpitz,
Germany) in February 2017. BC absorption at a wavelength of 870 ...nm was
measured by a photoacoustic extinctiometer, and BC physical properties (BC
mass concentration, core size distribution and coating thickness) were
measured by a single-particle soot photometer (SP2). Additionally, a
catalytic stripper was used to intermittently remove BC coatings by
alternating between ambient and thermo-denuded conditions. From these data
the mass absorption cross section of BC (MACBC) and its enhancement factor
(EMAC) were inferred for essentially water-free aerosol as present after
drying to low relative humidity (RH). Two methods were applied independently to investigate the
coating effect on EMAC: a correlation method (MACBC, ambient vs. BC coating
thickness) and a denuding method (MACBC, ambient vs. MACBC, denuded). Observed
EMAC values varied from 1.0 to 1.6 (lower limit from denuding method) or
∼1.2 to 1.9 (higher limit from correlation method), with the
mean coating volume fraction ranging from 54 % to 78 % in the dominating
mass equivalent BC core diameter range of 200–220 nm. MACBC and EMAC were
strongly correlated with coating thickness of BC. By contrast, other
potential drivers of EMAC variability, such as different BC sources (air mass
origin and absorption Ångström exponent), coating composition (ratio
of inorganics to organics) and BC core size distribution, had only minor effects. These results for ambient BC measured at Melpitz during winter show
that the lensing effect caused by coatings on BC is the main driver of the
variations in MACBC and EMAC, while changes in other BC particle properties
such as source, BC core size or coating composition play only minor roles at
this rural background site with a large fraction of aged particles. Indirect
evidence suggests that potential dampening of the lensing effect due to
unfavorable morphology was most likely small or even negligible.
Particle number size distributions between 3 nm and 10 μm were measured in Beijing, China. New particle formation events were observed on around 40% of the measurement days from March 2004 to ...February 2005 and were generally observed under low relative humidity and sunny conditions. Though occurring during all seasons, new particle formation events had highest frequency in spring and lowest frequency in summer. Events were classified as “clean” or “polluted” groups mainly according to the condensational sink and the local wind. The formation rate range was from 3.3 to 81.4 cm−3 s−1. The growth rate varied from 0.1 to 11.2 nm h−1. The seasonal variation of condensable vapor concentration showed the highest values during summer months due to enhanced photochemical and biological activities as well as stagnant air masses preventing exchange with cleaner air.
Exposure to black carbon (BC) in the residential environment was found to be positively associated with elevated blood pressure and cardiovascular disease. However, BC has been under-measured and ...under-studied compared to other common indoor gaseous and particulate pollutants. Representative indoor mass concentrations of equivalent black carbon (eBC) and the sources' contribution from indoors and outdoors in real-life residential environments in 40 German households were evaluated and presented in this work. During the 500 measurement days, the mean indoor eBC mass concentration was 0.6 µg m^(-3), which is less than half of the outdoor concentration in the urban background in Germany. However, common indoor sources contributed differently to indoor eBC, which also resulted in higher mass concentrations in the cold season than in the warm season. Indoor pollutant measurements are often performed with only a limited number of instruments and pollutant data. To fill in the missing knowledge of indoor BC, a proxy model was developed. This proxy model can predict indoor eBC concentrations based on existing indoor databases or in cases where direct measurements of indoor eBC concentrations are not available. Due to the complex influence of climate and indoor activities, the model separated six scenariosfor weather (including warm and cold seasons) and indoor activities (burning, non-burning, and other activities) for typical urban residential environments in Germany. In this study, indoor eBC mass concentrations were found to be best estimated by indoor and outdoor PM_1. For different scenarios, the model achieved a satisfactory to good coefficient of determination (0.49 ＜ R^2 ＜ 0.77). With the aid of this model, a more accurate prediction of indoor eBC mass concentration and the resulting exposure and health risk assessment can be achieved for households under similar climatic conditions and activity habits of the occupants, e.g., in Central Europe.
Few studies investigated residential particle concentration levels with a full picture of aerosol particles from 10 nm to 10 μm size range with size-resolved information, and none was performed in ...central Europe in the long-term in multiple homes. To capture representative diurnal and seasonal patterns of exposure to particles, and investigate the driving factors to their variations, measurements were performed in 40 homes for around two weeks each in Leipzig and Berlin, Germany. These over 500 days' measurements combined PM_(10) and PM_(2.5) mass concentrations, particle number concentration and size distribution (PNC and PNSD, 10-800 nm), CO_2 concentration, and residential activities diary into a unique dataset. Natural ventilation was dominated, the mean ventilation rate calculated from CO_2 measurements was 0.2 h^(-1) and 3.7 h^(-1) with closed and opened windows, respectively. The main findings of this study showed that, the residents in German homes were exposed to a significantly higher mass concentration of coarse particles than outdoors, thus indoor exposure to coarse particles cannot be described by outdoors. The median indoor PNC diurnal cycles were generally lower than outdoors (median I/O ratio 0.69). However, indoor exposure to particles was different in the cold and warm season. In the warm season, due to longer opening window periods, indoor sources' contribution was weakened, which also resulted in the indoor PNC and PNSD being very similar to the outdoors. In the cold season, indoor sources caused strong peaks of indoor PNC that exceeded outdoors, along with the relatively low penetration factor - 0.5 for all size ranges, and indoor particle losses, which was particularly effective in reducing the ultrafine PNC, resulting in a different particle exposure load than outdoors. This study provides a detailed understanding of residential particle exposure in multiple homes, facilitating future studies to assess health effects in residential environments.
The Campaigns of Air Quality Research in Beijing and Surrounding Region 2006 (CAREBeijing‐2006) were mainly focused on the influence of the regional aerosol on the air pollution in Beijing. The urban ...aerosol was characterized in detail. The particle size distributions were also compared to those measured at a regional site (Yufa) approximately 50 km south of the urban site at Peking University (PKU). At PKU, total particle number and volume concentrations were (1.8 ± 0.8) × 104 cm−3 and 83.5 ± 57.9 μm3 cm−3, respectively. Days in three consecutive summers of 2004, 2005, and 2006 were classified as polluted days with PM10 over 150 μg m−3 and nonpolluted days with lower PM10. On nonpolluted days, particle number size distributions showed a maximum at about 60 nm with Aitken mode particles dominating number concentration. On polluted days, the contribution of accumulation mode particles increased, shifting the maximum of the number size distribution to over 80 nm. On polluted days with stagnant meteorological conditions, secondary aerosol dominated, with SO42−, NO3−, and NH4+ accounting for over 60% of accumulation mode particle mass. Particle number size distributions at both sites were similar. Number and volume concentrations of total particles at Yufa were 6% and 12% lower, respectively; those of accumulation mode particles were 2% and 15% lower. This means that air pollution in Beijing is mainly a regional problem. The regional accumulation mode particles are a metric for assessing the air quality since they influence most the visibility and total mass concentration. Their number and volume concentrations on polluted days were 5 × 103 cm−3 and 30 μm3 cm−3, respectively. Five new particle formation (NPF) events with continuous smooth growth were observed at both PKU and Yufa during CAREBeijing‐2006. These NPF events are regional or semiregional. Growth rates at PKU ranged from 1.2 to 5.6 nm h−1, and formation rates ranged from 1.1 to 22.4 cm−3 s−1. SO42−, NH4+, and oxalate might be important contributors to NPF events.
Continuous measurements of aerosol number size distribution in the range of 3
nm–10
μm were performed in Pearl River Delta (PRD), China. These measurements were made during the period of 3 October to ...5 November in 2004 at rural/coastal site, Xinken (22°37′N, 113°35′E, 6
m above sea level), in the south suburb of Guangzhou City (22°37′N, 113°35′E, 6
m above sea level), using a Twin Differential Mobility Particle Sizer (TDMPS) combined with an Aerodynamic Particle Sizer (APS). The aerosol particles at Xinken were divided into four groups according to the observation results: nucleation mode particles (3–30
nm), Aitken mode particles (30–130
nm), accumulation mode particles (130–1000
nm) and coarse mode particles (1–10
μm). Concentrations of nucleation mode, Aitken mode and accumulation mode particles were observed in the same order of magnitude (about 10,000
cm
−3), among which the concentration of Aitken mode particle was the highest. The Aitken mode particles usually had two peaks: the morning peak may be caused by the land–sea circulation, which is proven to be important for transporting aged aerosols back to the sampling site, while the noon peak was ascribed to the condensational growth of new particles. New particle formation events were found on 7 days of 27 days, the new particle growth rates ranged from 2.2 to 19.8
nm
h
−1 and the formation rates ranged from 0.5 to 5.2
cm
−3
s
−1, both of them were in the range of typical observed formation rates (0.01–10
cm
−3
s
−1) and typical particle growth rates (1–20
nm
h
−1). The sustained growth of the new particles for several hours under steady northeast wind indicated that the new particle formation events may occur in a large homogeneous air mass.
The mass concentration of black carbon (BC) particles in the
atmosphere has traditionally been quantified with two methods: as elemental
carbon (EC) concentrations measured by thermal–optical ...analysis and as
equivalent black carbon (eBC) concentrations when BC mass is derived from
particle light absorption coefficient measurements. Over the last decade,
ambient measurements of refractory black carbon (rBC) mass concentrations
based on laser-induced incandescence (LII) have become more common, mostly
due to the development of the Single Particle Soot Photometer (SP2)
instrument. In this work, EC and rBC mass concentration measurements from
field campaigns across several background European sites (Palaiseau,
Bologna, Cabauw and Melpitz) have been collated and examined to identify the
similarities and differences between BC mass concentrations measured by the
two techniques. All EC concentration measurements in PM2.5 were
performed with the EUSAAR-2 thermal–optical protocol. All rBC
concentration measurements were performed with SP2 instruments calibrated with the same
calibration material as recommended in the literature. The observed values
of median rBC-to-EC mass concentration ratios on the single-campaign level were
0.53, 0.65, 0.97, 1.20 and 1.29, respectively, and the geometric standard
deviation (GSD) was 1.5 when considering all data points from all five
campaigns. This shows that substantial systematic bias between these two
quantities occurred during some campaigns, which also contributes to the
large overall GSD. Despite considerable variability in BC properties and
sources across the whole dataset, it was not possible to clearly assign
reasons for discrepancies to one or the other method, both known to have
their own specific limitations and uncertainties. However, differences in
the particle size range covered by these two methods were identified as one
likely reason for discrepancies. Overall, the observed correlation between rBC and EC mass reveals a linear
relationship with a constant ratio, thus providing clear evidence that both
methods essentially quantify the same property of atmospheric aerosols,
whereas systematic differences in measured absolute values by up to a factor
of 2 can occur. This finding for the level of agreement between two current
state-of-the-art techniques has important implications for studies based
on BC mass concentration measurements, for example for the interpretation of
uncertainties in inferred BC mass absorption coefficient values, which are
required for modeling the radiative forcing of BC. Homogeneity between BC
mass determination techniques is also very important for moving towards a routine BC
mass measurement for air quality regulations.
During the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition, the Balloon-bornE moduLar Utility for profilinG the lower Atmosphere (BELUGA) was deployed from ...an ice floe drifting in the Fram Strait from 29 June to 27 July 2020. The BELUGA observations aimed to characterize the cloudy Arctic atmospheric boundary layer above the sea ice using a modular setup of five instrument packages. The in situ measurements included atmospheric thermodynamic and dynamic state parameters (air temperature, humidity, pressure, and three-dimensional wind), broadband solar and terrestrial irradiance, aerosol particle microphysical properties, and cloud particle images. In total, 66 profile observations were collected during 33 balloon flights from the surface to maximum altitudes of 0.3 to 1.5 km. The profiles feature a high vertical resolution of 0.01 m to 1 m, including measurements below, inside, and above frequently occurring low-level clouds. This publication describes the balloon operations, instruments, and the obtained data set. We invite the scientific community for joint analysis and model application of the freely available data on PANGAEA.
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