Search

To develop effective strategies for controlling both PM 2.5 and O3 levels, it is crucial to understand their synergistic mechanisms and key precursors and the atmospheric physiochemical processes involved. In this study, a wintertime co-occurring O3 and PM 2.5 pollution event in a coastal city in southeast China was investigated based on high-time-resolution measurements of criteria air pollutants and chemical compositions of PM 2.5 , and O3 precursors, such as NOx , HCHO, and volatile organic compounds (VOCs). The results of this study revealed the characteristics of positively correlated PM 2.5 and MDA8 O3 concentrations, and an increase in atmospheric oxidation capacity (AOC) during the cold seasons. Strong correlations (R2= 0.415–0.477) between HCHO, Fe, Mn, and sulfate concentrations were observed, suggesting the influence of catalyzed oxidation processes in the coastal city. Through an observation-based model (OBM) analysis coupled with the Regional Atmospheric Chemistry Mechanism, version 2 (RACM2) and the Chemical Aqueous-Phase Radical Mechanism, version 3.0 (CAPRAM 3.0), we found that high concentrations of precursors (SO2 and HCHO), high relative humidity, and moderately acidic pH conditions enhanced the heterogeneous formation of hydroxymethanesulfonate (HMS) in PM 2.5. Furthermore, by employing an OBM coupled to the Master Chemical Mechanism (OBM-MCM), we verified that disabling the HCHO mechanism could decrease daytime net O3 production rates by reducing the production rates of HO2 + NO. These results were consistent with the daily values of AOC, OH, HO2 , and RO2 concentrations. This study contributes to a better understanding of the significance of HCHO in photochemical reactions and the formation of HMS in a coastal city. [ABSTRACT FROM AUTHOR]

Surface ozone (O3) pollution under global climate change has become one of the top environmental issues. In this study, we focused on the coastal region in Southeast China with relatively low O3 precursor's emissions and complicated synoptic conditions, where the O3 trends and meteorological contributions remain unclear. An increasing trend of O3 concentrations in the cities (0.3–4.6 μg m−3 yr−1) from 2015 to 2020 was observed. Twenty‐three synoptic patterns were clustered based on weather typing method, in which cyclone‐related types and southwesterly type were generally associated with low O3 concentrations, and high O3 levels occurred with anticyclone‐related types. Considering both frequency and intensity of synoptic patterns, reconstructed O3 series captured 46.0%–58.3% of the observed variability. Using Kolmogorov‐Zurbenko filter, an increasing trend of long‐term O3 was found. By implementing the multiple linear regression model between O3 concentrations and meteorological factors, the meteorological contributions to O3 variabilities (44.7%–66.1%) were quantified. The results indicated the meteorological conditions were particularly important in O3 pollution with the reductions of O3 precursor's emissions, among which relative humidity, boundary layer height, solar radiation along with low cloud cover were proved to play important roles. The weakening southwest winds along with more anti‐cyclone systems under climate change could increase surface O3. This study elucidated the crucial meteorological drivers on the O3 variability in relatively clean areas and implied the challenges for local governments to mitigate O3 pollution under global climate change. Plain Language Summary: Ozone (O3) pollution has become one of the top environmental issues in recent years and can be affected not only by O3 precursors (volatile organic compounds and nitrogen oxides) but also meteorological condition. Under global climate change, there is a need to deeply understand the impact of meteorological factors on surface O3 concentrations with the decrease of O3 precursors. In this study, we focus on the coast area of Southeast China with relatively low O3 precursors emissions and influenced by the East Asia monsoon. Temporal and spatial variations of O3 concentrations along with the meteorological impacts on O3 variabilities from 2015 to 2020 were analyzed. The results show that the relative meteorological contributions on O3 trends were 44.7%–66.1%. The higher temperature, lower relative humidity, more solar radiation, weakening southwest winds along with more anti‐cyclone systems under climate change could increase surface O3. This study is beneficial to understand different mechanisms of meteorological impacts on O3 variations in the relatively clean areas, and find out the key drivers to cause O3 pollution with the decrease of O3 precursors emissions and climate change. Key Points: Temporal and spatial variations of O3 concentrations in the coastal of southeast China from 2015 to 2020 were analyzedWeather typing was applied to identify the dominant synoptic patterns and related meteorological factors lead on high O3 concentrationThe contributions of synoptic patterns and meteorological factors on long‐term O3 trends were quantified [ABSTRACT FROM AUTHOR]

To develop the effective strategies for controlling both PM2.5 and O3 levels, it is crucial to understand their synergistic mechanisms, key precursors, and atmospheric physiochemical processes involved. In this study, a wintertime co-occurring O3 and PM2.5 pollution event in a coastal city in southeast China was investigated based on high-time resolution measurements of criteria air pollutants, chemical compositions of PM2.5, and O3 precursors, such as NOx, HCHO, and VOCs. The results of this study revealed a positive correlation between PM2.5 and MDA8 O3 concentrations during the whole periods, suggesting an increase in atmospheric oxidation capacity (AOC) during the cold seasons. Strong correlations (R2 = 0.415–0.477) were observed between HCHO, Fe, Mn, and sulfate concentrations, suggesting the influence of catalyzed oxidation processes in the coastal city. Through an observation-based model (OBM) analysis coupled with the regional atmospheric chemistry mechanism version 2 (RACM2) and the chemical aqueous-phase radical mechanism version 3.0 (CAPRAM 3.0), we found that high concentrations of precursors (SO2 and HCHO), high relative humidity, and moderately acidic pH conditions enhanced the heterogeneous formation of hydroxymethanesulfonate (HMS) in PM2.5. Furthermore, by employing the Master Chemical Mechanism (OBM-MCM), we verified that disabling the HCHO mechanism could decrease daytime net O3 production rates by reducing the production rates of HO2+NO. These results were consistent with the daily values of AOC, OH, HO2, and RO2 concentrations. This study contributes to a better understanding of the significance of HCHO in photochemical reactions and the formation of secondary aerosols in a coastal city. [ABSTRACT FROM AUTHOR]

In this study, we investigated how people evaluate behavioral interventions (BIs) that are targeted at themselves, aiming to promote their own health and wellbeing. We compared the impact on people's assessments of the acceptability of using BIs to change their own behavior of: the transparency of the BI (transparent or opaque); the designer of the BI (researchers, government policy-makers, advertisers); and three types of arguments regarding their efficacy (positive, positive + negative, negative). Our target BIs were actual interventions that have been used in a range of policy domains (diet, exercise, alcohol consumption, smoking, personal finances). We found that transparent BIs were considered more acceptable than opaque BIs. On average, all BIs were considered acceptable for changing participants' own behavior, except for the opaque BI in the finance context; there was differential acceptability of BIs across contexts, with finance clearly least acceptable. However, the perceived effectiveness of the BIs was at least as influential a predictor of acceptability ratings as the ease of identification of the behavior change mechanism across the five contexts. Furthermore, effectiveness was partially mediated by desire to change, suggesting that people do think BIs make them better off, 'as judged by themselves'. [ABSTRACT FROM AUTHOR]

The aim of this article is to cover three things: (1) to introduce the context behind why a report prepared by the Organisation for Economic Co-operation and Development (OECD) in 2017 would be of such importance to researchers in various academic disciplines and public policy, (2) to present the details of a simple classification system that was applied to all 111 case studies of behavioural interventions (better known as nudges) referred to in the OECD (2017a) report, and (3) to discuss what needs to be done to help advance practitioners' pursuit of effective behavioural interventions. This article aims to highlight the importance of accurately cataloguing the types of behavioural interventions that have been trialled/implemented across the world. By adopting an agreed classification system, researchers and practitioners can benefit from knowing what can work, and where it can work, as well as what does not work, in order to be better armed when considering the use of behavioural interventions to solve social policy issues. [ABSTRACT FROM AUTHOR]