Clean Air

Air pollution is a cause of disease for millions around the world and now more than ever urgent action is required to tackle the burden of its impacts. Doing so will not only improve both life expectancy and quality of life, but will also lead to a more just and sustainable world.

Air pollution is an environmental and health concern affecting millions globally every day. Professor Denise Mauzerall, an expert in air pollution and climate change at Princeton University, shares with Nature Communications their thoughts on the impacts of air pollution and the policies needed to tackle emissions.

Air pollution is an environmental and health concern affecting millions globally every day. Dr Audrey de Nazelle, an expert in air pollution risk assessment and exposure science at Imperial College London, shares with Nature Communications their thoughts on the impacts of air pollution and the policies needed to tackle emissions.

Air pollution and the associated health impacts affect millions of people around the world. In this Q&A, Professor Haikun Wang, an expert on the health risks of air pollution and climate change at Nanjing University, shares with Nature Communications their thoughts on the impacts of air pollution and the policies needed to tackle emissions.

Outdoor air pollution contributes to millions of deaths worldwide yet air pollution has differential exposures across racial/ethnic groups and socioeconomic status. While green infrastructure has the potential to decrease air pollution and provide other benefits to human health, vegetation alone cannot resolve health disparities related to air pollution injustice. We discuss how unequal access to green infrastructure can limit air quality improvements for marginalized communities and provide strategies to move forward.

Photocatalytic air purification is a promising technology that mimics nature’s photochemical process, but its practical applications are still limited despite considerable research efforts in recent decades. Here, we briefly discuss the progress and challenges associated with this technology.

How can scientists and policymakers work together to reduce the health impacts of air pollution? In this review paper, the authors discuss the interplay between advances in environmental exposure assessment and policy advances to tackle pollution in a focused way.

How sulfur dioxide emitted through coal combustion is oxidized to sulfate particles during winter haze pollution events has been the subject of debate. Here, the authors show that rapid oxidation takes place by nitrogen dioxide and nitrous acid, producing nitrous oxide together with sulfate.

Sulfate aerosols are an important component of wintertime haze events in China, but their production mechanisms are not well known. Here, the authors show that transition metal-catalyzed oxidation of SO₂ on aerosol surfaces could be the dominant sulfate formation pathway in Northern China.

It remains unclear how urban emissions influence the formation of secondary organic aerosols (SOA), including in the Amazon forest. Here, the authors simulate the formation of SOAs in the Amazon using a high-resolution regional chemical transport model. They find that urban emissions of NOx from Manaus enhance the production of biogenic SOA by 60–200%.

Size-resolved Black Carbon (BC) particle number emission inventory is not available for global civil aviation. Here the authors converted BC mass emission inventory into number emission inventory and found that aviation BC number emission contributes to 1.3% of total ground anthropogenic emissions and 3.6% on global average.

Nitrogen pollution is influenced by many stressors, and their combined effects are poorly constrained. Here the authors used a global land biosphere model to analyse the past two and a half centuries of land N pollution budgets and fluxes to the ocean and atmosphere and found that land sequesters 11% of global annual reactive N inputs.

Fires cause large perturbations to terrestrial carbon cycle through direct carbon emissions. Here the authors combine several models and measurement datasets and show that fires can indirectly worsen the carbon loss through the net negative impacts on ecosystem productivity from fire ozone and aerosols.

Aerosol effects on convection have been debated for decades when all types of aerosols are lumped together in the analyses. Using NASA satellite measurements, the authors find strong evidence that smoke inhibits convection but polluted continental aerosols invigorate convection.

Black carbon has a large but uncertain warming contribution to Earth’s climate. Here Matsui et al. show that black carbon mixing state and its interaction with aerosol size distribution are required for accurately estimating the radiative effect of black carbon.

The radiative forcing due to aerosol-cloud interactions constitutes one of the largest uncertainties of anthropogenic radiative forcing. Direct satellite measurements of the relevant aerosol properties reveal that the resulting cooling from anthropogenic aerosols is much stronger than previously thought.

Sunlight can change the composition of atmospheric aerosol particles, but the mechanisms through which this happens are not well known. Here, the authors show that fast radical reaction and slow diffusion near viscous organic particle surfaces can cause oxygen depletion, radical trapping and humidity dependent oxidation.

Satellite-based estimates of radiative forcing by aerosol–cloud interactions are consistently smaller than those from global models, hampering accurate projections of future climate change. Here, the authors show that the discrepancy can be substantially reduced by correcting sampling biases induced by inherent limitations of satellite measurements.

“How iodine-bearing molecules contribute to atmospheric aerosol formation is not well understood. Here, the authors provide a new gas-to-particle conversion mechanism and show that clustering of iodine oxides is an essential component of this process while previously proposed iodic acid does not play a large role.”

Summertime ozone air pollution in North China remains severe. Here the authors find large biogenic emissions of nitrogen oxides in North China, mainly driven by fertilizer application, challenge the mitigation of ozone pollution by only reducing combustion induced ozone precursors’ emissions.

There lacks a method to measure the rapid changes of vehicle emissions. Here the authors proposed a big data approach ‘TrackATruck’, and their estimates using the new approach show that the heavy-duty trucks (HDT) emissions of primary cargo routes/terminals were underestimated by 2–10 times in proxy-based emission inventories.

Household air pollution derived from cooking fuels is a major source of health and environmental problems. Here, the authors provide detailed global, regional and country estimates of cooking fuel usage from 1990 to 2030 and project that 31% of people will still be mainly using polluting fuels in 2030.

Ammonia emissions from agricultural sources can cause severe health impacts. Here, the authors show that about 25% of global agricultural ammonia emissions in 2012 were related to international exported goods and caused 61 thousand PM2.5 related premature deaths, which points out large ammonia mitigation potential in international trade.

Exposure to ambient particulate matter is one of the leading global health risks. Here, the authors reveal, by means of chemical multi-fingerprinting, the presence of exogenous ultrafine particles with diverse species and morphology in non-occupational human serum and pleural effusion.

The reason for a re-emergence of scarlet fever in China remains unclear. Here the authors show that the number of scarlet fever cases surged in 2011 peaking in 2018, this correlates with an increase in NO₂ and O₃ but does not necessarily imply causation.

Recent toxicological studies suggest that wildfire particulate matter may be more toxic than equal doses of ambient PM_2.5. Here, the authors show that even for similar exposure levels, PM_2.5 from wildfires is considerably more dangerous for respiratory health at the population level.

Mercury is a neurotoxin and pollutant with enhanced emissions from anthropogenic activities. Here, the authors develop a global emissions, transport, and human risk model and find substantial future losses in revenue and public health if emission reductions proposed by the Minamata Convention are delayed.

Open fires can increase heavy exposure to hazardous particulate matters, and thus harm human health, particularly among the vulnerable individuals, such as pregnant women. Here, the authors show an association between maternal exposure to fire smoke and increased risk of pregnancy loss in South Asia.

Ambient fine particulate matter (PM_2.5) is one of the most important environmental health risk factors in many regions. Here, the authors present an assessment of PM_2.5 emission sources and the related health impacts across global to sub-national scales and find that over 1 million deaths were avoidable in 2017 by eliminating PM_2.5 mass associated with fossil fuel combustion emissions.

Air pollution can affect people’s emotional status and well-being. Here, the authors simulate fixed-scene images to show that under the atmospheric conditions in Beijing, negative emotions occur when air quality index of PM_2.5 increases to approximately 150.

Air pollution has become a major health risk in China. Here Zhang et al. report that maternal and neonatal exposure to particulate matter increases the risk of neonatal jaundice based on the study of 25,782 newborns born in China between 2014 and 2017.

Exposure to air pollution during pregnancy has been associated with impaired birth outcomes. Here, Bové et al. report evidence of black carbon particle deposition on the fetal side of human placentae, including at early stages of pregnancy, suggesting air pollution could affect birth outcome through direct effects on the fetus.

Individuals with different genotypes may respond differently to environmental variation. Here, Favé et al. find substantial impacts of different environment exposures on the transcriptome and clinical endophenotypes when controlling for genetic ancestry by analyzing data from ∼1000 individuals from a founder population in Quebec.

Modulation of ambient PM_2.5 exposure and premature mortality burden in India under climate change scenarios is unclear. Here the authors show that the premature mortality burden is projected to decrease in 2100 relative to present day under all possible combined climate change and socioeconomic pathways scenarios.

Considering air pollution-induced health risks from a consumption perspective is important. Here the authors evaluated the premature deaths resulting from household consumption across 30 Chinese provinces and find that rural households can cause a similar number of pollution-induced deaths as urban households despite a larger and wealthier urban population, due to the combustion of solid fuel.

Residential solid fuel use constitutes a large amount of air pollution but has been gradually replaced by other cleaner energy during the past three decades. Here the authors investigated the contribution of rural residential sector to ambient PM_2.5 pollution and the resulting climate forcing and health impacts, and find that the remaining large quantities of solid fuels used in rural households are still a major contributor to ambient air pollution despite of decrease in its pollutant emissions and relative contribution to PM_2.5 due to the clean energy transition.

Recent efforts to link mental health to environmental factors have focused on single predictors such as pollution or temperature anomalies. Here, the authors show that declines in self-assessed mental health scores were linked to increases in air pollution and temperature variability.

Exposure to ambient particulate matter is a key contributor to disease in India and source attribution is vital for pollution control. Here the authors use a high-resolution regional model to show residential emissions dominate particulate matter concentrations and associated premature mortality.

Decoupling emission reduction target determination, air pollution modelling, and health benefit estimation complicates control strategy design. Here an integrated approach identifies strategies to reduce health damages of air pollution, showing that benefits can be achieved cost-effectively by electrifying sources with high primary PM_2.5 emission intensities.

Chinese government has implemented the air pollution control measure-the Air Pollution Prevention and Control Action Plan in 2013, whose effects have not been fully studied. Here the authors show that from 2013 to 2017, the plan has achieved substantial public health benefits.

Global largest agricultural ammonia (NH₃) emissions in China have caused severe damage to both ecosystem and human health, yet no policy is formulated to reduce NH₃ emissions. Here, the authors show that halving agricultural NH₃ emissions with feasible technical mitigation options in China generates far more societal benefits than abatement costs.

The environmental and socio-economic implications of the growth in welfare and trade in Asia-Pacific (APAC) remain unclear. Here the authors show that over the past two decades (1995–2015), owing to intraregional trade, the APAC economies have grown increasingly interdependent in natural resource use, air emissions, and labor and economic productivity.

The global supply chain and demand for export goods can lead to relocated emissions. Goods produced in China for foreign markets have lead to an increase of domestic non-methane volatile organic compounds emissions by 3.5 million tons in 2013 resulting in potentially an estimated 16,889 premature deaths annually.

Local air quality co-benefits can provide convincing support for climate action. Here the authors revisited air quality co-benefits of climate action in the context of NDCs and found that 71–99 thousand premature deaths can be avoided each year by 2030, offsetting the climate mitigation costs on a global level.

Carbon dioxide emissions and air pollution are often assessed on a national or regional level, but little is known about the role of trade structures. Here, a combination of models shows that trade restrictions can lead to massive reduction of gross domestic product in most countries, but also to a reduction of emissions and pollution.

Chinese government has implemented regulations to reduce mining-related methane emission since 2010. Here the authors estimated methane emissions in China using GOSAT satellite observation and results reveal a business-as-usual increase in methane emissions since 2010 despite those ambitious targets.

Aerosol impacts have not been comprehensively considered in the cost-benefit integrated assessment models that are widely used to analyze climate policy. Here the authors account for these impacts and find that the health co-benefits from improved air quality outweigh the co-harms from increased near-term warming, and that optimal climate policy results in immediate net benefits globally.

Aerosol pollution from shipping contributes to cooling but also leads to premature mortality and morbidity. Here the authors combine emission inventories, atmospheric models and health risk functions to show how cleaner marine fuels will reduce premature deaths and childhood asthma but results in larger warming.

Particulate matter pollution is a public health concern in industrialized and urban areas. Here, the authors control the surface chemistry and microstructure of filtration materials to fabricate effective and transparent air filters for the capture of PM_2.5pollutants.

Particulate matter (PM) pollutants have been considered serious threats to public health but effective removal of nanoscale particles (NPs) by filter materials is challenging. Here, the authors fabricate an ionic liquid based self-powered air filter that can be used in high-efficiency removal of PM, including NPs.

Supported metal single-atom catalysts face challenges on both durability and practicality. Here, the authors demonstrate that a sustained 90% diesel oxidation conversion at ~160 ^oC is achieved by single-atom Pt on TiO₂ nanowire-array integrated catalytic converter.

Personal protective air filtration masks are becoming increasingly desirable, but most commercial air purifiers have poor biocidal capabilities. Here the authors fabricate metal–organic framework-based air filters with both high particulate matter removal efficiencies and photocatalytic bactericidal properties.

Nanofibrous networks are applied in environmental protection and electrical or bioengineering and experience a great demand, but the design of these functional materials is challenging. Here the authors demonstrate an electronetting technology for fabricating self-assembled nanonets from various materials.

State‐of‐the‐art aerosol nanoparticle techniques are limited by the shortcomings of removing the nanoparticles from their original environment. Here, the authors apply small angle X‐ray scattering as an in‐situ measurement technique, enabling the measurement of the primary particles and the aggregates.

Cationic metal-organic frameworks provide promising opportunities to capture anionic pollutants, but stable frameworks with sufficiently large pores are lacking. Here the authors present a thorium-based mesoporous, cationic and hydrolytically-stable MOF that can rapidly trap inorganic and organic anionic pollutants.