Volatile chemical products emerging as largest petrochemical source of urban organic emissions

Science, Год журнала: 2018, Номер 359(6377), С. 760 - 764

Опубликована: Фев. 16, 2018

Air pollution evolution Transport-derived emissions of volatile organic compounds (VOCs) have decreased owing to stricter controls on air pollution. This means that the relative importance chemicals in pesticides, coatings, printing inks, adhesives, cleaning agents, and personal care products has increased. McDonald et al. show these chemical now contribute fully one-half emitted VOCs 33 industrialized cities (see Perspective by Lewis). Thus, focus efforts mitigate ozone formation toxic burdens need be adjusted. Science , this issue p. 760 ; see also 744

Язык: Английский

---

Recent advances in understanding secondary organic aerosol: Implications for global climate forcing

Reviews of Geophysics, Год журнала: 2017, Номер 55(2), С. 509 - 559

Опубликована: Май 18, 2017

Abstract Anthropogenic emissions and land use changes have modified atmospheric aerosol concentrations size distributions over time. Understanding preindustrial conditions in organic due to anthropogenic activities is important because these features (1) influence estimates of radiative forcing (2) can confound the historical response climate increases greenhouse gases. Secondary (SOA), formed atmosphere by oxidation gases, represents a major fraction global submicron‐sized aerosol. Over past decade, significant advances understanding SOA properties formation mechanisms occurred through measurements, yet current models typically do not comprehensively include all processes. This review summarizes some developments during decade formation. We highlight importance processes that growth particles sizes relevant for clouds forcing, including extremely low volatility organics gas phase, acid‐catalyzed multiphase chemistry isoprene epoxydiols, particle‐phase oligomerization, physical such as viscosity. Several highlighted this are complex interdependent nonlinear effects on properties, formation, evolution SOA. Current neglect complexity nonlinearity thus less likely accurately predict project future sensitivity Efforts also needed rank most influential process‐related interactions, so be represented chemistry‐climate models.

Язык: Английский

---

Particulate matter, air quality and climate: lessons learned and future needs

Atmospheric chemistry and physics, Год журнала: 2015, Номер 15(14), С. 8217 - 8299

Опубликована: Июль 24, 2015

Abstract. The literature on atmospheric particulate matter (PM), or aerosol, has increased enormously over the last 2 decades and amounts now to some 1500–2000 papers per year in refereed literature. This is part due enormous advances measurement technologies, which have allowed for an increasingly accurate understanding of chemical composition physical properties particles their processes atmosphere. growing scientific interest aerosol high importance environmental policy. In fact, constitutes one most challenging problems both air quality climate change policies. this context, paper reviews recent results within sciences policy needs, driven much increase monitoring mechanistic research decades. synthesis reveals many new developments science underpinning climate–aerosol interactions effects PM human health environment. However, while airborne responsible globally important influences premature mortality, we still do not know relative different components these effects. Likewise, magnitude overall remains highly uncertain. Despite uncertainty there are things that could be done mitigate local global PM. Recent analyses shown reducing black carbon (BC) emissions, using known control measures, would reduce warming delay time when anthropogenic temperature exceed °C. cost-effective measures ammonia, agricultural precursor gas secondary inorganic aerosols (SIA), regional eutrophication concentrations large areas Europe, China USA. Thus, environment population. A prioritized list actions full range currently undeliverable shortcomings knowledge science; among shortcomings, roles sources response land use remaining century prominent. any case, evidence from strongly advocates integrated approach

Язык: Английский

---

Nitrate radicals and biogenic volatile organic compounds: oxidation, mechanisms, and organic aerosol

Atmospheric chemistry and physics, Год журнала: 2017, Номер 17(3), С. 2103 - 2162

Опубликована: Фев. 13, 2017

Oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO3) represents one important interactions between anthropogenic emissions related to combustion and natural from biosphere. This interaction has been recognized for more than 3 decades, during which time a large body research emerged laboratory, field, modeling studies. NO3-BVOC reactions influence air quality, climate visibility through regional global budgets reactive nitrogen (particularly nitrates), ozone, aerosol. Despite its long history significance this topic in atmospheric chemistry, number uncertainties remain. These include an incomplete understanding rates, mechanisms, aerosol yields reactions, lack constraints on role heterogeneous oxidative processes associated with NO3 radical, difficulty characterizing spatial distributions BVOC within poorly mixed nocturnal atmosphere, challenge constructing appropriate boundary layer schemes non-photochemical mechanisms use state-of-the-art chemical transport chemistry-climate models. review is result workshop same title held at Georgia Institute Technology June 2015. The first half summarizes current literature particular focus recent advances instrumentation models, secondary (SOA) formation chemistry. Building understanding, second outlines impacts chemistry quality climate, suggests critical needs better constrain improve predictive capabilities

Язык: Английский

---

Review of Urban Secondary Organic Aerosol Formation from Gasoline and Diesel Motor Vehicle Emissions

Environmental Science & Technology, Год журнала: 2016, Номер 51(3), С. 1074 - 1093

Опубликована: Дек. 21, 2016

Secondary organic aerosol (SOA) is formed from the atmospheric oxidation of gas-phase compounds leading to formation particle mass. Gasoline- and diesel-powered motor vehicles, both on/off-road, are important sources SOA precursors. They emit complex mixtures that vary in volatility molecular structure—factors influence their contributions urban SOA. However, relative importance each vehicle type with respect remains unclear due conflicting evidence recent laboratory, field, modeling studies. Both likely important, evolving location over short time scales. This review summarizes evidence, research needs, discrepancies between top-down bottom-up approaches used estimate focusing on inconsistencies molecular-level understanding regional observations. The effect emission controls (e.g., exhaust aftertreatment technologies, fuel formulation) precursor emissions needs comprehensive evaluation, especially international perspective given heterogeneity regulations technology penetration. Novel studies needed identify quantify "missing" appear contribute substantially production, gasoline vehicles most advanced aftertreatment. Initial suggests catalyzed diesel particulate filters greatly reduce precursors along primary aerosol.

Язык: Английский

---

The AeroCom evaluation and intercomparison of organic aerosol in global models

Atmospheric chemistry and physics, Год журнала: 2014, Номер 14(19), С. 10845 - 10895

Опубликована: Окт. 15, 2014

Abstract. This paper evaluates the current status of global modeling organic aerosol (OA) in troposphere and analyzes differences between models as well observations. Thirty-one chemistry transport (CTMs) general circulation (GCMs) have participated this intercomparison, framework AeroCom phase II. The simulation OA varies greatly terms magnitude primary emissions, secondary (SOA) formation, number species used (2 to 62), complexity parameterizations (gas-particle partitioning, chemical aging, multiphase chemistry, microphysics), physical, optical properties. diversity results has increased since earlier experiments, mainly due increasing SOA parameterization models, implementation new, highly uncertain, sources. Diversity over one order exists modeled vertical distribution concentrations that deserves a dedicated future study. Furthermore, although / OC ratio depends on sources atmospheric processing, is important for model evaluation against observations, it resolved only by few models.

median (POA) source strength 56 Tg a⁻¹ (range 34–144 a⁻¹) (natural anthropogenic) 19 13–121 a⁻¹). Among take into account semi-volatile nature, calculated be 51 16–121 a⁻¹), much larger than value calculate more simplistic way (19 a⁻¹; range 13–20 a⁻¹, with at 37 burden 1.4 (24 0.6–2.0 4 2.0 3.8 Tg), lifetime 5.4 days 3.8–9.6 days). In reported both sulfate burdens, OA/sulfate 0.77; 13 lower 1, 9 higher 1. For 26 deposition fluxes, wet removal 70 28–209 which average 85% total deposition. Fine carbon (OC) observations from continuous monitoring networks individual field campaigns been evaluation. At urban locations, model–observation comparison indicates missing knowledge anthropogenic sources, seasonality. combined model–measurements analysis suggests existence levels during summer biogenic formation large areas USA can same POA, even contribute measured seasonal pattern. Global are able simulate high character observed atmosphere result POA amount present remains largely underestimated, mean normalized bias (MNB) equal −0.62 (−0.51) based data all surface, −0.15 (+0.51) when compared remote measurements, −0.30 marine locations data. temporal correlations across stations low measurements: 0.47 (0.52) stations, 0.39 (0.37) 0.25 combination (negative) MNB correlation sites about processes govern removal, top their stations. There no clear change skill regard or mass concentration. However, needed distinguish natural climate mitigation, impact accurately.

Язык: Английский

---

Secondary organic aerosol reduced by mixture of atmospheric vapours

Nature, Год журнала: 2019, Номер 565(7741), С. 587 - 593

Опубликована: Янв. 30, 2019

Язык: Английский

---

One-year simulation of ozone and particulate matter in China using WRF/CMAQ modeling system

Atmospheric chemistry and physics, Год журнала: 2016, Номер 16(16), С. 10333 - 10350

Опубликована: Авг. 16, 2016

Abstract. China has been experiencing severe air pollution in recent decades. Although an ambient quality monitoring network for criteria pollutants constructed over 100 cities since 2013 China, the temporal and spatial characteristics of some important pollutants, such as particulate matter (PM) components, remain unknown, limiting further studies investigating potential control strategies to improve associating human health outcomes with exposure. In this study, a yearlong (2013) simulation using Weather Research Forecasting (WRF) model Community Multi-scale Air Quality (CMAQ) was conducted provide detailed information ozone (O3), total PM2.5, chemical components. Multi-resolution Emission Inventory (MEIC) used anthropogenic emissions observation data obtained from national were collected validate performance. The successfully reproduces O3 PM2.5 concentrations at most months, performance statistics meeting criteria. However, overprediction generally occurs low concentration range while underprediction happens summer. Spatially, better southern than northern central Sichuan Basin. Strong seasonal variations exist wind speed direction play roles high events. Secondary components have more boarder distribution primary Sulfate (SO42−), nitrate (NO3−), ammonium (NH4+), organic aerosol (POA) are All highest winter except secondary (SOA). This study proves ability CMAQ reproduce identifies directions where improvements needed, provides exposure multiple assessing effects.

Язык: Английский

---

New Particle Formation in the Atmosphere: From Molecular Clusters to Global Climate

Journal of Geophysical Research Atmospheres, Год журнала: 2019, Номер 124(13), С. 7098 - 7146

Опубликована: Июнь 25, 2019

Abstract New particle formation (NPF) represents the first step in complex processes leading to of cloud condensation nuclei. Newly formed nanoparticles affect human health, air quality, weather, and climate. This review provides a brief history, synthesizes recent significant progresses, outlines challenges future directions for research relevant NPF. developments include emergence state‐of‐the‐art instruments that measure prenucleation clusters newly nucleated down about 1 nm; systematic laboratory studies multicomponent nucleation systems, including collaborative experiments conducted Cosmics Leaving Outdoor Droplets chamber at CERN; observations NPF different types forests, extremely polluted urban locations, coastal sites, polar regions, high‐elevation sites; improved theories parameterizations account atmospheric models. The lack understanding fundamental chemical mechanisms responsible aerosol growth under diverse environments, effects SO 2 NO x on NPF, contribution anthropogenic organic compounds It is also critical develop can detect composition particles from 3 20 nm improve represent over wide range conditions precursor, temperature, humidity.

Язык: Английский

---

Differential toxicities of fine particulate matters from various sources

Scientific Reports, Год журнала: 2018, Номер 8(1)

Опубликована: Ноя. 13, 2018

Abstract Fine particulate matters less than 2.5 µm (PM ) in the ambient atmosphere are strongly associated with adverse health effects. However, it is unlikely that all fine particles equally toxic view of their different sizes and chemical components. Toxicity produced from various combustion sources (diesel engine, gasoline biomass burning (rice straw pine stem burning), coal combustion) non-combustion (road dust including sea spray aerosols, ammonium sulfate, nitrate, secondary organic aerosols (SOA)), which known major PM , was determined. Multiple biological endpoints were integrated for source-specific to derive toxicity scores originating sources. The highest score obtained diesel engine exhaust particles, followed by road dust, suggesting traffic plays most critical role enhancing effects particles. ranking can be used better understand caused particle types atmosphere, provide practical management beyond what achieved only using mass current regulation standard.

Язык: Английский

---