High summer background O levels in the desert of northwest China.

Generally speaking, the precursors of ozone (O), nitrogen oxides and volatile organic compounds are very low in desert areas due to the lack of anthropogenic emissions and natural emissions, and thus O concentrations are relatively low. However, high summer background concentrations of about 100 µg/m or 60 ppb were found in the Alxa Desert in the highland of northwest China based on continuous summer observations from 2019 to 2021, which was higher than the most of natural background areas or clean areas in world for summer O background concentrations. The high O background concentrations were related to surface features and altitude.

The interactions of aerosol and planetary boundary layer over a large city in the Mongolian Plateau.

The interactions of aerosol and planetary boundary layer (PBL) play a crucial role in deteriorating the air quality in vast urban agglomeration areas in eastern China. However, there remains a lacking of report regarding their performance in the hazy events in Mongolian Plateau cities in northern China. In this study, half-month (01-16 January 2020) physical and material datasets of the PBL measured by multi instrumentations mounted in downtown Hohhot, a largest Mongolian Plateau city, are statistically analyzed.

Analysis of severe ozone-related human health and weather influence over China in 2019 based on a high-resolution dataset.

Ozone pollution in 2019 in China is particularly severe posing a tremendous threat to the health of Chinese inhabitants. In this study, we constructed a more reliable and accurate 1-km gridded dataset for 2019 with as many sites as possible using the inverse distance weight interpolation method to analyze spatiotemporal ozone pollution characteristics and health burden attributed to ozone exposure from the perspective of different diseases and weather influence. The accuracy of this new dataset is higher than other public datasets, with the coefficient of determination of 0.

Geochemical characteristics and socioeconomic associations of carbonaceous aerosols in coal-fueled cities with significant seasonal pollution pattern.

Carbonaceous aerosols, comprising organic carbon (OC) and elemental carbon (EC), are critical component of fine particulate matter (PM), with diverse impacts on air quality and human health. This study investigated the concentrations and seasonal patterns of carbonaceous species in PM during both the heating season (January 2021) and non-heating season (July 2021) in three coal-fueled cities in northern China, as well as the differences in carbonaceous aerosols and their associations with socioeconomic parameters in cities situated on either side of the "Hu Line" in China. The results showed that, owing to intensified coal combustion and unfavorable meteorological conditions, levels of OC, EC, and OC/EC ratios were higher in winter compared to summer.

Short-term joint effects of ambient PM and O on mortality in Beijing, China.

Introduction: In recent years, air pollution caused by co-occurring PM and O, named combined air pollution (CAP), has been observed in Beijing, China, although the health effects of CAP on population mortality are unclear.

Methods: We employed Poisson generalized additive models (GAMs) to evaluate the individual and joint effects of PM and O on mortality (nonaccidental, respiratory, and cardiovascular mortality) in Beijing, China, during the whole period (2014-2016) and the CAP period. Adverse health effects were assessed for percentage increases (%) in the three mortality categories with each 10-μg/m increase in PM and O.

Refractory black carbon aerosols in rainwater in the summer of 2019 in Beijing: Mass concentration, size distribution and wet scavenging ratio.

Black carbon (BC) aerosols in the atmosphere play a significant role in climate systems due to their strong ability to absorb solar radiation. The lifetime of BC depends on atmospheric transport, aging and consequently on wet scavenging processes (in-cloud and below-cloud scavenging). In this study, sequential rainwater samples in eight rainfall events collected in 2 mm interval were measured by a tandem system including a single particle soot photometer (SP2) and a nebulizer.

The feedback effects of aerosols from different sources on the urban boundary layer in Beijing China.

The interaction of aerosols and the planetary boundary layer (PBL) plays an important role in deteriorating urban air quality. Aerosols from different sources may have different effects on regulating PBL structures owing to their distinctive dominant compositions and vertical distributions. To characterize the complex feedback of aerosols on PBL over the Beijing megacity, multiple approaches, including in situ observations in the autumn and winter of 2016-2019, backward trajectory clusters, and large-eddy simulations, were adopted.

The urgent need to control volatile organic compound pollution over the Qinghai-Tibet Plateau.

Owing to the impact of the western development of China, there have been signs of air pollution over the Qinghai-Tibet Plateau in recent years. However, monitoring data on atmospheric volatile organic compounds (VOCs) are lacking in plateau areas. Here, VOCs concentrations in urban and background areas in North China and the Qinghai-Tibet Plateau were observed from 2012 to 2014 and 2020 to 2022, respectively.

Causal effect of PM on morbidity of cause-specific respiratory diseases based on a negative control exposure.

Background: Extensive studies have linked PM and PM with respiratory diseases (RD). However, few is known about causal association between PM and morbidity of RD. We aimed to assess the causal effects of PM on cause-specific RD.

Modification effects of ambient temperature on ozone-mortality relationships in Chengdu, China.

A multitude of epidemiological studies have demonstrated that both ambient temperatures and air pollution are closely related to health outcomes. However, whether temperature has modification effects on the association between ozone and health outcomes is still debated. In this study, three parallel time-series Poisson generalized additive models (GAMs) were used to examine the effects of modifying ambient temperatures on the association between ozone and mortality (including non-accidental, respiratory, and cardiovascular mortality) in Chengdu, China, from 2014 to 2016.

Transport Patterns and Potential Sources of Atmospheric Pollution during the XXIV Olympic Winter Games Period.

The attainment of suitable ambient air quality standards is a matter of great concern for successfully hosting the XXIV Olympic Winter Games (OWG). Transport patterns and potential sources of pollutants in Zhangjiakou (ZJK) were investigated using pollutant monitoring datasets and a dispersion model. The PM concentration during February in ZJK has increased slightly (28%) from 2018 to 2021, mostly owing to the shift of main potential source regions of west-central Inner Mongolia and Mongolian areas (2015-18) to the North China Plain and northern Shanxi Province (NCPS) after 2018.

The environmental benefit of Beijing-Tianjin-Hebei coal banning area for North China.

In order to achieve the targets specified in the Action Plan for Air Pollution Prevention and Control (APAPPC), a limited coal banning area (10,000 km) was designated in the heavily polluted Beijing-Tianjin-Hebei region (BTH) for the first time in 2017. PM and elements were sampled by the network of BTH to evaluate the effectiveness of this policy. This study found that the fine days with PM < 75 μg m accounted for 74.

Observational Insights into Isoprene Secondary Organic Aerosol Formation through the Epoxide Pathway at Three Urban Sites from Northern to Southern China.

Isoprene is the most abundant precursor of global secondary organic aerosol (SOA). The epoxide pathway plays a critical role in isoprene SOA (iSOA) formation, in which isoprene epoxydiols (IEPOX) and/or hydroxymethyl-methyl-α-lactone (HMML) can react with nucleophilic sulfate and water producing isoprene-derived organosulfates (iOSs) and oxygen-containing tracers (iOTs), respectively. This process is complicated and highly influenced by anthropogenic emissions, especially in the polluted urban atmospheres.

Mass and number concentration distribution of marine aerosol in the Western Pacific and the influence of continental transport.

We quantify for the first time marine aerosol properties and their differences in the offshore and remote ocean in the mid-latitude South Asian waters, low-latitude South Asian waters, and equatorial waters of the Western Pacific Ocean, based on shipboard cruise observations conducted by the Western Pacific Ocean Scientific Observation Network in winter 2018, and further investigate the effects of long-range transport of continental aerosols on the marine environment. During the overall observation period, the average number concentration of particle matter which aerodynamic diameters<2.5 μm (PM) was 35.

Air stagnation in China: Spatiotemporal variability and differing impact on PM and O during 2013-2018.

In recent years, winter PM and summer O pollution which often occurred with air stagnation condition has become a major concern in China. Thus, it is imperative to understand the air stagnation distribution in China and elucidate its impact on air pollution. In this study, three air stagnation indices were calculated according to atmospheric thermal and dynamics parameters using ERA5 data.

How do aerosols above the residual layer affect the planetary boundary layer height?

We revealed that the absorption aerosol lying below or above the morning residual layer (MRL) promotes (stove effect, heating the MRL layer) or strongly inhibits (dome effect, heating the temperature inversion layer) the development of planetary boundary layer (PBL) after sunrise, while scattering aerosol exhibits similar suppression (surface or aloft umbrella effect) on the PBL regardless of its vertical location. However, the role of different type of aerosols (i.e.

Vertical evolution of black and brown carbon during pollution events over North China Plain.

The vertical distribution of carbonaceous aerosol impacts climate change, air quality and human health, but there is a lack of in-situ vertical observations of black (BC) and brown carbon (BrC). Thus, the characteristic of vertical profiles of BC concentration, particle number concentration (PNC), O concentration and optical absorption of BC and BrC were observed in a suburban site over North China Plain, where heavy pollution of PM and O always occurred in winter and summer, respectively. In winter, during a heavy pollution episode, the BC and PNC was near uniformly distributed within mixing layer (ML) (15.

The dynamic multi-box algorithm of atmospheric environmental capacity.

It is very important for air pollution prevention and control to accurately quantify atmospheric environment capacity (AEC) in the planetary boundary layer (PBL). This study developed a high temporal-resolution dynamic multi-box algorithm to estimate PM AEC with a PBL ceilometer and Doppler wind profile lidar in Beijing City. Compared with the traditional A-value method, two primary improvements are introducing the time coefficient and vertical multi-box assumption into the original box model.

Effects of the sea-land breeze on coastal ozone pollution in the Yangtze River Delta, China.

Aim at the effects of the coastal characteristic on ozone pollution in the Yangtze River Delta (YRD), a campaign was launched at the Ningbo, China in the summer of 2020, which mainly covered the monitoring of the vertical profiles of ozone (O) concentration, three-dimensional wind field, temperature and humidity profiles and parameters of boundary layer dynamic-thermodynamic structure. At the coastal research station, a sea-land breeze (SLB) circulation accompanied by a concurrent coastal low-level jets (CLLJ) structure was observed and identified during 11-12 May 2020. The sea breeze first formed at 10:00 LT on 11 May, turned to land breeze at night, and returned to sea breeze again at 10:00 LT the next morning, prevailing at altitudes of 0-0.

Exploring the variation of black and brown carbon during COVID-19 lockdown in megacity Wuhan and its surrounding cities, China.

Absorbing carbonaceous aerosols, i.e. black and brown carbon (BC and BrC), affected heavily on climate change, regional air quality and human health.

Polycyclic aromatic hydrocarbons induce endothelial injury through miR-155 to promote atherosclerosis.

Polycyclic aromatic hydrocarbons (PAHs) are considered as an external factor that induces atherosclerotic cardiovascular disease. Although miR-155 is known to be involved in cardiovascular disease, whether it is involved in PAH-induced arteriosclerosis remains unclear. We evaluated the effects of PAHs on vascularization, permeability, and miR-155 expression in HUVECs.

A comprehensive evaluation of aerosol extinction apportionment in Beijing using a high-resolution time-of-flight aerosol mass spectrometer.

An aerosol mass spectrometer (AMS) was used to measure the chemical composition of non-refractory submicron particles (NR-PM) in Beijing from 2012 to 2013. The average concentration of NR-PM was 56 μg·m, with higher value of 106 μg·m when Beijing was influenced by air masses from south in winter. Organics was the primary chemical component with a concentration of 26 μg·m, accounting for 46% of the total NR-PM.

Characteristics of chemical profile, sources and PAH toxicity of PM in beijing in autumn-winter transit season with regard to domestic heating, pollution control measures and meteorology.

Several air pollution episodes occurred in Beijing before and after the 2014 Asia-Pacific Economic Cooperation (APEC) summit, during which air-pollution control measures were implemented. Within this autumn-winter transit season, domestic heating started. Such interesting period merits comprehensive chemical characterization, particularly the organic species, to look into the influence of additional heating sources and the control measures on air pollution.