The magnitudes of toxicities and effects of the ambient concentration of total mass (weight) of particulate matter with aerodynamic diameter less than 2.5 μm (PM2.5) on adverse health outcomes manifest regional- and temporal-specific heterogeneity due to the variability of embedded chemical components. To explore acute hazards of 39 chemical components of PM2.5 on cause-specific emergency department

In the present study, a multicolor conversion strategy based on gold nanorods (AuNRs) assisted silver mirror reaction is developed for visual quantification of formaldehyde (HCHO). The method involves the silver deposition on the surface of AuNRs via the reduction reaction of Tollens' reagent in the presence of HCHO. The peak shifts of the longitudinal localized surface plasmon resonance (LSPR) and

Aerosol optical properties have been analyzed to investigate seasonal and regional variability of aerosols and to classify their key types over the Middle East region during the period 2001–2019. The collection 6.1 MODIS aerosol products are used, including daily values of aerosol optical depth (AOD) and the Ångström exponent (AE) data. The MODIS aerosol retrieval has been verified using measurements

A dust plume rising to a maximum altitude of about 1 km above the springtime high-Arctic terrain of Lake Hazen, Nunavut, Canada was detected using a diverse array of passive and active, satellite-based remote sensing techniques. We were able to broadly characterize the 532 nm optical depth and particle size of the upper plume (0.5 ± 0.2 and 15–25 μm radius limits respectively). To our knowledge this

The Data Assimilation Research Testbed (DART) has been extended to be able to assimilate the column-average dry-air mole fraction of CO2 (XCO2) retrievals from the Orbiting Carbon Observatory 2 (OCO-2) satellite. Atmospheric CO2 concentrations over the Midwestern United States were estimated by the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), with and without assimilating

Dust inputs to the oligotrophic waters of the subtropical North Atlantic are of significant importance to the biogeochemistry of the region. In this work, we present fluxes of particles, soluble elements (H+, major ions, Fe and organic ions) in dry deposition (DD) and wet deposition (WD) samples collected between September 2012 and April 2016. Positive Matrix Factorization Model (PMF) indicated four

The use of air sensor technology is increasing worldwide for a variety of applications, however, with significant variability in data quality. The United States Environmental Protection Agency held a workshop in July 2019 to deliberate possible performance targets for air sensors measuring particles with aerodynamic diameters of 10 μm or less (PM10), nitrogen dioxide (NO2), carbon monoxide (CO), and

Background Exposure to ambient fine particulate matter (PM2.5) increases the mortality burden. Exposure windows and exposure-response functions (ERFs) are two critical components of accurate mortality burden estimation. Objective We explored the potential heterogeneity of exposure windows and reassessed the PM2.5-attributable mortality burden in China with novel ERFs. Method Based on 1 km × 1 km satellite-retrieved

Air quality policies based on scientific and technical information are effective for controlling air pollution and protecting public health. Analysis of observations from periodic intensive field studies combined with updated emission inventories, air quality monitoring and numerical modeling can be used to address the causes that trigger air pollution and catalyze the design of cost-effective emissions

A real-time numerical source apportionment system was established based on the operational regional atmospheric environmental modelling system (RAEMS) for eastern China in order to calculate the contribution of emissions from different provincial regions over the Yangtze River Delta (YRD) region to the PM2.5 concentration. The 2019 modelling results showed good and reliable performance of the RAEMS

Large uncertainties exist in the current treatment of atmospheric dry deposition and air-surface exchange of atmospheric mercury in chemical transport models and monitoring networks. To quantitatively assess these uncertainties, two existing bidirectional air-surface flux exchange models for gaseous elemental mercury (Hg0), originally developed by Wang et al. (2014, Atmos. Chem. Phys., doi:10.5194/acp-14-6273-2014)

Ozone (O3) photochemistry in remote areas can be altered by the injection of long-range transported air masses which contain volatile organic compounds (VOCs) and nitrogen oxides (NOx). In this study, VOCs and trace gases (i.e., SO2, NO, NO2, CO, and O3) were measured in summer (August) and autumn (October) in 2018 at Jinsha (JSH), a regional background station in central China. A unique pattern that

Background In response to the COVID-19 pandemic, the Bavarian State government announced several COVID-19 mitigation measures beginning on March 16, 2020, which likely led to a reduction in traffic and a subsequent improvement in air quality. In this study, we evaluated the short-term effect of COVID-19 mitigation measures on NO2 concentrations in Munich, Germany. Methods We applied two quasi-experimental

Atmospheric tracers are effective tools for characterizing dispersion and for testing computational models of atmospheric transport. Atmospheric trace gas measurements are now used widely to infer geographical surface flux distributions. However, robust flux estimates critically rely on well-validated knowledge of atmospheric chemistry, loss processes and transport, without which we are not fully realizing

Background Nine COVID-19 (Corona Virus Disease, 2019) cases were observed in one community in Guangzhou. All the cases lived in three vertically aligned units of one building sharing the same piping system, which provided one unique opportunity to examine the transmission mode of SARS-CoV-2. Methods We interviewed the cases on the history of travelling and close contact with the index patients. Respiratory

The ozone reaction of γ-terpinene (1-isopropyl-4-methyl-1,4-cyclohexadiene), a monoterperne emitted by Elm, Cypress, Waterhickory and Maple trees, has been investigated at 294 ± 2 K, atmospheric pressure and under dry conditions (relative humidity, RH < 2%) in two simulation chambers of the LPCA laboratory in Dunkerque (France): CHARME (CHamber for the Atmospheric Reactivity and the Metrology of the

Ozone is a serious health concern and the only major pollutant in Ontario that is increasing, despite major efforts to control atmospheric pollutants in North America. Ambient ozone levels are affected by local atmospheric conditions (temperature, humidity, radiation, precipitation) and the concentration of its main precursors, nitrogen oxides (NOx) and volatile organic compounds (VOCs). In the present

The evolution of aerosol absorption and the contribution of absorbing species under different severities of particulate pollution are poorly understood, though absorption is key in aerosol radiative forcing. To resolve the problems, aerosol absorbing properties from low to high particulate pollution were investigated by using intensive observations of aerosol optical properties in the winter of 2019–2020

Better understanding of fine particulate matter (PM2.5) composition and sources associated with brown carbon (BrC) and reactive oxygen species (ROS) are essential for developing effective air quality control strategies to mitigate climate warming and protect human health. To identify the common chemical composition and sources associated with BrC and ROS, BrC light absorption and hydroxyl radical (·OH)

We selected a typical developed city in east China, Nanjing, to evaluate the effect of recent national and local policies of air pollution control on emissions and air quality at city scale. Using a bottom-up methodology, the annual emissions of SO2, NOX, CO, NH3, primary fine particle matters (PM2.5), black carbon, and organic carbon were estimated to decline 70%, 22%, 49%, 72%, 64%, 65%, and 86%

Secondary organic aerosols (SOA) are an important component of fine particulate matter (PM2.5). However, photochemical models often have difficulty capturing the observed magnitudes of SOA due to uncertainties in precursor emissions and modeling approach. In this study, we conducted a modeling study of SOA in the Yangtze River Delta (YRD) region of China to investigate the impact of emissions of i

Biogenic volatile organic compounds (BVOCs) have an important impact on atmospheric chemistry. Mixing ratio of BVOCs in different ecosystems have been measured and discussed in detail in recent decades. However, field measurements from tropical Africa remain scarce. In this study, we present the mixing ratio of BVOCs, including isoprene, monoterpenoids, sesquiterpenes, bornylacetate, and 2–methyl–3–buten–2–ol

In this study, an effective method with a multi-channel Raman-Mie lidar has been proposed to detect the hygroscopic growth of atmospheric aerosol in the boundary layer, and the effect of aerosol hygroscopic growth on the optical and microphysical properties of aerosol particles is studied. The vertical relative humidity profile is obtained by combining calibrated water vapor mixing ratio and temperature

Recent research has used mobile methane (CH4) measurements to identify and quantify emissions, but the effect of instrument response time on concentration measurements is rarely considered. Furthermore, stable isotope ratios are increasingly used in mobile measurements to attribute sources, but the precision of mobile isotopic measurements depend on a combination of instrument and measurement conditions

The nitrogen isotopic composition (δ15N) of atmospheric nitrate aerosols is determined by both the δ15N of its precursor, NOx emissions, and the isotopic fractionations during the atmospheric oxidation of NOx. However, the latter has not been well-understood nor quantified by field observations. In addition, the seasonal variations of this isotopic fractionation have not been determined. To better

Wintertime Arctic frontal positions can be particularly important in determining the inclusion of mercury emissions from anthropogenic sources in the Arctic. Using the streamline confluence method, we constructed a climatology of wintertime (November–March) Arctic frontal positions during 1988–2017, examined their long-term variations, and assessed the impact of such variations on Arctic anthropogenic

Continuous monitoring of precipitation chemistry began at the Hubbard Brook Experimental Forest, NH in June 1963, and it was there that acid rain was discovered in North America. Some independent monitoring of precipitation chemistry in central New York was done in 1970–1971. The MAP3S network (Charlottesville, VA, Ithaca, NY, Penn State, PA, Whiteface Mt., NY) began in 1976 and became part of the

Public transport is commonly associated with benefits such as reducing road traffic congestion and improving air quality. This paper focuses on evaluating the causal impact of a new public transport provision in London, the Jubilee Line Extension (JLE) in 1999, on air quality. Using meteorological normalisation and a regression discontinuity design with time as the forcing variable, we show that the

The 1990 Clean Air Act Amendments (CAAA) launched a new era in environmental protection. New provisions created the innovative Acid Rain Program to curtail acid-rain-causing emissions from the electric power sector through an allowance trading program. Success implementing this new type of program led to its expanded use to achieve additional power plant emission reductions in support of the CAAA "Good

To investigate tropospheric ozone, O3, and secondary organic aerosols, SOAs, reactivities of biogenic volatile organic compounds, BVOCs, with atmospheric oxidants have been focused on. In this study, as an ensemble monitor covering all ozone-reactive BVOCs, the analyzer of total ozone reactivity, RO3, was modified and applied to the ambient observation of RO3 in a forest. The analyzer was improved

A 16-year (2003–2018) evaluation of CO, NO2, SO2, O3, and PM10 from three reanalysis products (CAMS, TCR-2, and MERRA-2) against independent observations and intercomparison among reanalyses are performed over South Korea. All three reanalyses show significant and persistent biases in the five pollutants, but the reanalyses partly capture decreasing trends in CO, NO2, SO2, and PM10 and increasing trends

The changes in aerosol optical and microphysical properties, and sub-band shortwave direct radiative forcing (DARF) in Beijing and Wuhan were compared at different haze levels in winters. The occurrence of haze is found to be governed by the wind circulation and boundary layer in Beijing where the ground wind speed and the height of boundary layer decreased significantly with the development of haze

The National Institute of Environmental Research, the Ministry of Environment, has been forecasting the concentrations of particulate matter (PM) with a diameter ≤ 2.5 μm (PM2.5) over Seoul, Republic of Korea, in terms of four PM2.5 concentration categories (low, moderate, high, and very high) since August 31, 2013. The current model, the Community Multiscale Air Quality (CMAQ) model, is run four times

In this study, we examined the effects of vertical turbulent diffusion on the absolute and relative strengths of foreign and domestic source contributions. We chose the Northeast Asia region because of the important transboundary air pollution issues requiring a sound understanding of source-receptor relationships in the region. We performed photochemical grid modeling by setting two different minimum