Source sector and fuel contributions to ambient PM2.5 and attributable mortality across multiple spatial scales

Nature Communications, Год журнала: 2021, Номер 12(1)

Опубликована: Июнь 14, 2021

Ambient fine particulate matter (PM2.5) is the world's leading environmental health risk factor. Reducing PM2.5 disease burden requires specific strategies that target dominant sources across multiple spatial scales. We provide a contemporary and comprehensive evaluation of sector- fuel-specific contributions to this 21 regions, 204 countries, 200 sub-national areas by integrating 24 global atmospheric chemistry-transport model sensitivity simulations, high-resolution satellite-derived exposure estimates, disease-specific concentration response relationships. Globally, 1.05 (95% Confidence Interval: 0.74–1.36) million deaths were avoidable in 2017 eliminating fossil-fuel combustion (27.3% total burden), with coal contributing over half. Other included residential (0.74 [0.52–0.95] deaths; 19.2%), industrial (0.45 [0.32–0.58] 11.7%), energy (0.39 [0.28–0.51] 10.2%) sectors. Our results show regions large anthropogenic generally had highest attributable deaths, suggesting substantial benefits from replacing traditional sources. one most important factors many regions. Here, authors present an assessment emission related impacts scales find 1 mass associated fossil fuel emissions.

Язык: Английский

---

Persistent Heavy Winter Nitrate Pollution Driven by Increased Photochemical Oxidants in Northern China

Environmental Science & Technology, Год журнала: 2020, Номер 54(7), С. 3881 - 3889

Опубликована: Март 3, 2020

Nitrate is an increasingly important component of fine particulate matter (PM2.5) during winter in northern China. Past emission control has been ineffective reducing nitrate. Here, we use extensive observations and a model with state-of-the-art nitrogen chemistry to identify the key factors that nitrate formation heavily polluted North China Plain (NCP). In contrast previous view weak photochemistry, show O3 OH productions are sufficiently high facilitate fast gas-phase heterogeneous conversion NOX over NCP. Increasing from higher precursor levels ROX cycling accelerate generation heavy pollution. We find 31.8% reduction emissions 2010 2017 NCP lowers surface by only 0.2% even increases some areas. This mainly due increase (by ∼30%), which subsequently increased efficiency HNO3 38.7%). Future strategies for haze should also aim lower photochemical oxidants, via larger synchronized VOCs reduction, overcome effects nonlinear photochemistry aerosol chemical feedback.

Язык: Английский

---

Control of particulate nitrate air pollution in China

Nature Geoscience, Год журнала: 2021, Номер 14(6), С. 389 - 395

Опубликована: Апрель 26, 2021

Язык: Английский

---

Fast Photochemistry in Wintertime Haze: Consequences for Pollution Mitigation Strategies

Environmental Science & Technology, Год журнала: 2019, Номер 53(18), С. 10676 - 10684

Опубликована: Авг. 16, 2019

In contrast to summer smog, the contribution of photochemistry formation winter haze in northern mid-to-high latitude is generally assumed be minor due reduced solar UV and water vapor concentrations. Our comprehensive observations atmospheric radicals relevant parameters during several events 2016 Beijing, however, reveal surprisingly high hydroxyl radical oxidation rates up 15 ppbv/h, which comparable values reported photochemical smog two three times larger than those determined previous Birmingham (Heard et al. Geophys. Res. Lett. 2004, 31, (18)), Tokyo (Kanaya J. Res.: Atmos. 2007, 112, (D21)), New York (Ren Environ. 2006, 40, 252-263). The active facilitates production secondary pollutants. It mainly initiated by photolysis nitrous acid ozonolysis olefins maintained an extremely efficiently cycling process driven nitric oxide. This boosted recycling generates fast ozone that are again smog. ozone, currently masked its efficient chemical removal nitrogen oxides contributing level wintertime particles. future emission regulations, such as reduction oxide emissions, therefore facing challenge reducing avoiding increase pollution at same time. Efficient control strategies mitigate Beijing may require measures similar implemented avoid summer.

Язык: Английский

---

The global impacts of COVID-19 lockdowns on urban air pollution

Elementa Science of the Anthropocene, Год журнала: 2021, Номер 9(1)

Опубликована: Янв. 1, 2021

The coronavirus-19 (COVID-19) pandemic led to government interventions limit the spread of disease which are unprecedented in recent history; for example, stay at home orders sudden decreases atmospheric emissions from transportation sector. In this review article, current understanding influence emission reductions on pollutant concentrations and air quality is summarized nitrogen dioxide (NO2), particulate matter (PM2.5), ozone (O3), ammonia, sulfur dioxide, black carbon, volatile organic compounds, carbon monoxide (CO). first 7 months following onset pandemic, more than 200 papers were accepted by peer-reviewed journals utilizing observations ground-based satellite instruments. Only about one-third literature incorporates a specific method meteorological correction or normalization comparing data lockdown period with prior reference despite importance doing so interpretation results. We use stringency index (SI) as an indicator severity measures show how key pollutants change SI increases. observed decrease NO2 increasing general agreement inventories that account lockdown. Other compounds such O3, PM2.5, CO also broadly covered. Due chemistry O3 PM2.5 concentrations, their responses may not be linear respect primary pollutants. At most sites, we found increased, whereas decreased slightly, SI. Changes other understudied. highlight future research needs emerging sets preview state atmosphere world targeted permanent emissions. Finally, emphasize need effects meteorology, trends, when determining concentrations.

Язык: Английский

---

Field Determination of Nitrate Formation Pathway in Winter Beijing

Environmental Science & Technology, Год журнала: 2020, Номер 54(15), С. 9243 - 9253

Опубликована: Июнь 26, 2020

Particulate nitrate (pNO3–) has often been found to be the major component of fine particles in urban air-sheds China, United States, and Europe during winter haze episodes recent years. However, there is a lack knowledge regarding experimentally determined contribution different chemical pathways formation pNO3–. Here, for first time, we combine ground tall-tower observations quantify pNO3– using observationally constrained model approach based on direct OH N2O5 air-shed. We find that gas-phase oxidation pathway (OH+NO2) daytime dominant channel over nocturnal uptake pollution episodes, with percentages 74% areas 76% suburban areas. This quite from previous studies some regions US, which was concluded account larger winter. These results indicate driving factor Beijing US different, as are mitigation strategies particulate nitrate.

Язык: Английский

---

Ozone chemistry in western U.S. wildfire plumes

Science Advances, Год журнала: 2021, Номер 7(50)

Опубликована: Дек. 8, 2021

Wildfires are a substantial but poorly quantified source of tropospheric ozone (O3). Here, to investigate the highly variable O3 chemistry in wildfire plumes, we exploit situ chemical characterization western wildfires during FIREX-AQ flight campaign and show that production can be predicted as function experimentally constrained OH exposure, volatile organic compound (VOC) reactivity, fate peroxy radicals. The exhibits rapid transition regimes. Within few daylight hours, formation substantially slows is largely limited by abundance nitrogen oxides (NOx). This finding supports previous observations enhanced when VOC-rich smoke mixes into NOx-rich urban thereby deteriorating air quality. Last, relate underlying fire characteristics, enabling more accurate representation atmospheric models used study quality predict climate.

Язык: Английский

---

Increased night-time oxidation over China despite widespread decrease across the globe

Nature Geoscience, Год журнала: 2023, Номер 16(3), С. 217 - 223

Опубликована: Янв. 26, 2023

Nitrogen oxides (NOx = NO + NO2) emitted from combustion and natural sources are reactive gases that regulate the composition of Earth's atmosphere. Nocturnal oxidation driven by nitrate radicals is an important but poorly understood process in atmospheric chemistry, affecting lifetimes NOx ozone particulate pollution levels. Understanding trends to formulating effective mitigation strategies understanding influence on climate. Here we analyse publicly available monitoring data assess production rates surface 2014 2021 across globe. We show have undergone strong increases China during 2014–2019 exhibited modest decreases United States European Union. Accelerated night-time has shortened lifetime summer 30% 2014–2019. This change will strongly affect formation policy implications for joint control fine pollution. Measurements increased decreased Union 2019. suggests increasing contribution air

Язык: Английский

---

The formation and mitigation of nitrate pollution: comparison between urban and suburban environments

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(7), С. 4539 - 4556

Опубликована: Апрель 8, 2022

Abstract. Ambient nitrate has been of increasing concern in PM2.5, while there are still large uncertainties quantifying the formation aerosol. The pathways aerosol at an urban site and a suburban Pearl River Delta (PRD) investigated using observation-constrained box model. Throughout campaigns, pollution episodes were constantly accompanied with increase concentrations fractions both sites. simulations demonstrate that chemical reactions daytime night contributed significantly to boundary layer two However, nighttime predominantly occurred aloft residual site, downward transport from morning is important source (53 %) for surface whereas similar amounts produced nocturnal which results little ground site. We show was volatile-organic-compound-limited (VOC-limited) regime transition identical response ozone reduction VOC emissions can be efficient approach mitigate areas through influencing hydroxyl radical (OH) N2O5 production, will also beneficial synergistic control regional pollution. highlight relative importance site-specific, quantitative understanding various provide insights developing mitigation strategies.

Язык: Английский

---

Overview of the Alaskan Layered Pollution and Chemical Analysis (ALPACA) Field Experiment

ACS ES&T Air, Год журнала: 2024, Номер 1(3), С. 200 - 222

Опубликована: Фев. 21, 2024

The Alaskan Layered Pollution And Chemical Analysis (ALPACA) field experiment was a collaborative study designed to improve understanding of pollution sources and chemical processes during winter (cold climate low-photochemical activity), investigate indoor pollution, dispersion as affected by frequent temperature inversions. A number the research goals were motivated questions raised residents Fairbanks, Alaska, where held. This paper describes measurement strategies conditions encountered January February 2022 experiment, reports early examples how measurements addressed goals, particularly those interest residents. Outdoor air showed high concentrations particulate matter pollutant gases including volatile organic carbon species. During events, low winds extremely stable atmospheric trapped below 73 m, an shallow vertical scale. Tethered-balloon-based intercepted plumes aloft, which associated with power plant point through transport modeling. Because cold spend much their time indoors, included quality component, made inside outside house infiltration sources. In absence activities such cooking and/or heating pellet stove, lower than outdoors; however, stove burns often caused higher outdoors. mass-normalized oxidative potential, health-relevant property measured here reactivity dithiothreiol, particles varied source, having less potential per mass particles.

Язык: Английский

---