Modeling assessment of air pollution control measures and COVID-19 pandemic on air quality improvements over Greater Bay Area of China.

A remarkable progress has been made toward the air quality improvements over the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) of China from 2017 to 2020. In this study, for the first time, the emission reductions of regional control measures together with the COVID-19 pandemic were considered simultaneously into the development of the GBA's emission inventories for the years of 2017 and 2020. Based on these collective emission inventories, the impacts of control measures, meteorological variations together with temporary COVID-19 lockdowns on the five major air quality index pollutants (SO, NO, PM, PM, and O, excluding CO) were evaluated using the WRF-CMAQ and SMAT-CE model attainment assessment tool over the GBA region.

Ambient volatile organic compounds at a receptor site in the Pearl River Delta region: Variations, source apportionment and effects on ozone formation.

We present the continuously measurements of volatile organic compounds (VOCs) at a receptor site (Wan Qing Sha, WQS) in the Pearl River Delta (PRD) region from September to November of 2017. The average mixing ratios of total VOCs (TVOCs) was 36.3 ± 27.

Trends of outdoor air pollution and the impact on premature mortality in the Pearl River Delta region of southern China during 2006-2015.

Severe air pollution in the Pearl River Delta (PRD) region of southern China has increased attention of both the scientific community and policy makers. Air quality data collected at the PRD Regional Air Quality Monitoring Network during 2006-2015 were analyzed for assessing the effectiveness of pollution control measures and for estimating the trends of premature mortality attributable to ambient PM and O. Statistically significant decreasing trends were detected for PM (-1.

Health benefit of air quality improvement in Guangzhou, China: Results from a long time-series analysis (2006-2016).

Numerous epidemiologic studies on adverse health effects of air pollution have been well documented; however, assessment on health benefits of air quality improvement from air pollution control measures has been limited in developing countries. We assessed the mortality benefits associated with air pollution improvement over 11 years in Guangzhou, China (2006-2016). A time series analysis with Generalized additive Poisson models was used to estimate mortality effects of ozone (O) and nitrogen dioxide (NO), adjusting for time trend, day of week, public holiday, temperature and relative humidity.

Are current Chinese national ambient air quality standards on 24-hour averages for particulate matter sufficient to protect public health?

With rapid economic development and urbanization in recent decades, China has experienced the worsening of ambient air quality. For better air quality management to protect human health, Chinese government revised national ambient air quality standards (NAAQS) for particulate matter (PM) in 2012 (GB3095-2012). To assess the effectiveness of current NAAQS for PM on public health in Chinese population, we conducted a meta-analysis on published studies examining the mortality risk of short-term exposure to PM with aerodynamic diameters less than 10 and 2.

Temporal variations in ambient particulate matter reduction associated short-term mortality risks in Guangzhou, China: A time-series analysis (2006-2016).

Numerous studies have reported associations between ambient particulate matter (PM) and daily mortality; however, little is known about temporal variations in ambient air pollution associated mortality risks, particularly in developing countries with limited long time-series air monitoring data. In present study, we assessed the associations and temporal relationships between ambient PM and daily mortality in Guangzhou, China, during 2006-2016. With this unique 11-year dataset, we related daily concentrations of PM with aerodynamic diameter < 2.

Seasonal cycles of secondary organic aerosol tracers in rural Guangzhou, Southern China: The importance of atmospheric oxidants.

Thirteen secondary organic aerosol (SOA) tracers of isoprene (SOA), monoterpenes (SOA), sesquiterpenes (SOA) and aromatics (SOA) in fine particulate matter (PM) were measured at a Pearl River Delta (PRD) regional site for one year. The characteristics including their seasonal cycles and the factors influencing their formation in this region were studied. The seasonal patterns of SOA, SOA and SOA tracers were characterized over three enhancement periods in summer (I), autumn (II) and winter (III), while the elevations of SOA tracer (i.

Species-specified VOC emissions derived from a gridded study in the Pearl River Delta, China.

This study provides a top-down approach to establish an emission inventory of volatile organic compounds (VOC) based on ambient measurements, by combining the box model and positive matrix factorization (PMF) model. Species-specified VOC emissions, source contributions, and spatial distributions are determined based on regional-scale gridded measurements between September 2008 to December 2009 in the Pearl River Delta (PRD), China. The most prevalent anthropogenic species in the PRD was toluene estimated by the box model to be annual emissions of 167.

Proteins and Amino Acids in Fine Particulate Matter in Rural Guangzhou, Southern China: Seasonal Cycles, Sources, and Atmospheric Processes.

Water-soluble proteinaceous matter including proteins and free amino acids (FAAs) as well as some other chemical components was analyzed in fine particulate matter (PM) samples collected over a period of one year in rural Guangzhou. Annual averaged protein and total FAAs concentrations were 0.79 ± 0.

Source apportionment of PM at urban and suburban areas of the Pearl River Delta region, south China - With emphasis on ship emissions.

Daily PM samples were collected at an urban site in Guangzhou in 2014 and at a suburban site in Zhuhai in 2014-2015. Samples were subject to chemical analysis for various chemical components including organic carbon (OC), element carbon (EC), major water-soluble inorganic ions, and trace elements. The annual average PM mass concentration was 48±22μgmand 45±25μgm in Guangzhou and Zhuhai, respectively, with the highest seasonal average concentration in winter and the lowest in summer at both sites.

Speciated OVOC and VOC emission inventories and their implications for reactivity-based ozone control strategy in the Pearl River Delta region, China.

The increasing ground-ozone (O3) levels, accompanied by decreasing SO2, NO2, PM10 and PM2.5 concentrations benefited from air pollution control measures implemented in recent years, initiated a serious challenge to control Volatile Organic Compound (VOC) emissions in the Pearl River Delta (PRD) region, China. Speciated VOC emission inventory is fundamental for estimating Ozone Formation Potentials (OFPs) to identify key reactive VOC species and sources in order to formulate efficient O3 control strategies.

A refined 2010-based VOC emission inventory and its improvement on modeling regional ozone in the Pearl River Delta Region, China.

Accurate and gridded VOC emission inventories are important for improving regional air quality model performance. In this study, a four-level VOC emission source categorization system was proposed. A 2010-based gridded Pearl River Delta (PRD) regional VOC emission inventory was developed with more comprehensive source coverage, latest emission factors, and updated activity data.

Organosulfates from pinene and isoprene over the Pearl River Delta, South China: seasonal variation and implication in formation mechanisms.

Biogenic organosulfates (OSs) are important markers of secondary organic aerosol (SOA) formation involving cross reactions of biogenic precursors (terpenoids) with anthropogenic pollutants. Until now, there has been rare information about biogenic OSs in the air of highly polluted areas. In this study, fine particle (PM2.

Fast increasing of surface ozone concentrations in Pearl River Delta characterized by a regional air quality monitoring network during 2006-2011.

Based on the observation by a Regional Air Quality Monitoring Network including 16 monitoring stations, temporal and spatial variations of ozone (O3), NO2 and total oxidant (O(x)) were analyzed by both linear regression and cluster analysis. A fast increase of regional O3 concentrations of 0.86 ppbV/yr was found for the annual averaged values from 2006 to 2011 in Guangdong, China.

Systematic review of Chinese studies of short-term exposure to air pollution and daily mortality.

Health effects attributable to air pollution exposure in Chinese population have been least understood. The authors conducted a meta-analysis on 33 time-series and case-crossover studies conducted in China to assess mortality effects of short-term exposure to particulate matter with aerodynamic diameters less than 10 and 2.5 μm (PM10 and PM2.

Estimated acute effects of ambient ozone and nitrogen dioxide on mortality in the Pearl River Delta of southern China.

Background And Objectives: Epidemiologic studies have attributed adverse health effects to air pollution; however, controversy remains regarding the relationship between ambient oxidants [ozone (O₃) and nitrogen dioxide (NO₂)] and mortality, especially in Asia. We conducted a four-city time-series study to investigate acute effects of O₃ and NO₂ in the Pearl River Delta (PRD) of southern China, using data from 2006 through 2008.

Methods: We used generalized linear models with Poisson regression incorporating natural spline functions to analyze acute mortality in association with O₃ and NO₂, with PM₁₀ (particulate matter ≤ 10 μm in diameter) included as a major confounder.

Site location optimization of regional air quality monitoring network in China: methodology and case study.

Regional air quality monitoring networks (RAQMN) are urgently needed in China due to increasing regional air pollution in city clusters, arising from rapid economic development in recent decades. This paper proposes a methodological framework for site location optimization in designing a RAQMN adapting to air quality management practice in China. The framework utilizes synthetic assessment concentrations developed from simulated data from a regional air quality model in order to simplify the optimal process and to reduce costs.

Acute mortality effects of carbon monoxide in the Pearl River Delta of China.

Objectives: Several studies reported acute mortality and morbidity effects of exposure to carbon monoxide (CO); which, however, has been least studied in Chinese population at regional scale.

Methods: We conducted a time-series analysis assessing mortality effects of CO in four cities located in the Pearl River Delta (PRD) of China, a labor and resource intensive city cluster, using daily mortality and air pollution data (2006-2008). Generalized linear model with Poisson regression incorporating natural spline functions was used to analyze the effects of exposure to ambient CO on total (nonaccidental), cardiovascular and respiratory mortality.

Characteristics of particulate matter pollution in the Pearl River Delta region, China: an observational-based analysis of two monitoring sites.

Two-year monitoring data (2006 and 2009), collected at the sub-urban site (WQS) and the background site (TH), were used to study the characteristics of Particulate Matter (PM) pollution in the Pearl River Delta region, China. Similar levels of PM(2.5) concentration measured at both sites seem to confirm that the fine particles have emerged as a major regional pollution issue.

[Characterizing spatial patterns of NO(x), SO2 and O3 in Pearl River Delta by passive sampling].

Concentrations of NO(x), SO2 and O3 were measured by passive sampling within 200km x 200km grid in Pearl River Delta (PRD). Sampling period was two weeks in November, 2009. Spatial distributions of NO(x), SO2 and O3 were obtained by Kriging interpolation method.

[Anthropogenic ammonia emission inventory and characteristics in the Pearl River Delta Region].

Based on the collected activity data and emission factors of anthropogenic ammonia sources, a 2006-based anthropogenic ammonia emission inventory was developed for the Pearl River Delta (PRD) region by source categories and cities with the use of appropriate estimation methods. The results show: (1) the total NH3 emission from anthropogenic sources in the PRD region was 194. 8 kt; (2) the agriculture sources were major contributors of anthropogenic ammonia sources, in which livestock sources shared 62.

[Development of non-road mobile source emission inventory for the Pearl River Delta region].

Based on the collected activity data and emission factors, the Pearl River Delta (PRD) regional non-road mobile source emission inventory was developed by categories with the use of appropriate estimation methods for different non-road mobile sources. The results show that the total emissions of SO2, NOx,VOC, CO and PM10 from non-road mobile sources in the PRD region were about 6.52 x 10(4) t, 1.

Road-network-Based spatial allocation of on-road mobile source emissions in the Pearl River Delta region, China, and comparisons with population-based approach.

Gridded air pollutant emission inventories are prerequisites for using air quality models to assess air pollution control strategies and predict air quality. A precise gridded emission inventory will help improve the accuracy of air quality simulation. Mobile source emissions are one of the major contributors to volatile organic compound (VOC) and nitrogen oxide (NOx) pollutants, the precursors of ozone formation.

Speciated VOC emission inventory and spatial patterns of ozone formation potential in the Pearl River Delta, China.

The Pearl River Delta region (PRD) of China has long suffered from severe ground-level ozone pollution. Knowledge of the sources of volatile organic compounds (VOCs) is essential for ozone chemistry. In this work, a speciated VOC emission inventory was established on the basis of updated emissions and local VOC source profiles.

Ground-level ozone in the Pearl River Delta and the roles of VOC and NO(x) in its production.

In many regions of China, very rapid economic growth has been accompanied by air pollution caused by vehicle emissions. In one of these regions, the Pearl River Delta, the variations of ground-level ozone and its precursors were investigated. Overall, the ambient concentrations of NO(2) increased quickly between 1995 and 1996, but then slightly decreased due to stringent nitrogen oxide (NO(x)) emission controls.