Sources and Emissions of Air Pollutants in Beijing (Manchester)

Lead Research Organisation: University of Manchester
Department Name: Earth Atmospheric and Env Sciences


Beijing suffers from very high concentrations of airborne pollutants, leading to adverse health and wellbeing for over twenty million people. The pollutants likely to have the greatest effects upon human health are particulate matter, nitrogen dioxide and ozone. Both particulate matter and nitrogen dioxide are emitted directly from individual sources (primary contributions, many of which are not well quantified); and are formed in the atmosphere (secondary contributions, which are highly complex). Ozone is entirely secondary in nature, formed from reactions of precursor gases, whose sources and abundance are also challenging to constrain. These uncertainties hinder understanding of the causes of air pollution in Beijing, which is needed to deliver effective and efficient strategies for pollution reduction and health improvement.

AIRPOLL-Beijing project will address this challenge, through identification and quantification of the sources and emissions of air pollutants in Beijing. The project sits within the NERC/MRC-NSFC China megacity programme, which includes projects addressing the atmospheric processes affecting air pollutants, human exposure and health effects, and solutions / mitigation strategies to reduce air pollution and health impacts.

The project exploits the combined experience and expertise of leading UK and Chinese scientists, applying multiple complementary approaches. The project deploys multiple atmospheric measurement and analysis strategies to characterise pollutant abundance and sources, develop novel emissions inventories, and integrate these to produce new modelling tools for use in policy development. We adopt a range of state-of-the-science approaches:

-Receptor Modelling, where detailed composition measurements are used to infer pollutant sources from their chemical signatures, combining world-leading UK and Chinese capability.

-Flux Measurements, where the total release of pollutants from all sources is measured, providing a key metric to refine emission inventories. We will combine near-ground measurements (using the unique Institute of Atmospheric Physics 325m tower in central Beijing), ground-based observations and fluxes derived from satellite observations.

-3D spatial analysis, in which a novel sensor network will be deployed around central Beijing to measure pollutant fields.

-Development of novel emissions inventories, which will predict the temporally- and spatially- resolved emissions of air pollutants from all sources, enhancing existing capability.

-Development of new online modelling tools, within which to integrate emissions, atmospheric processing and meteorology to predict primary and secondary pollutant concentration fields.

AIRPOLL-Beijing will integrate these approaches to provide thorough understanding of the sources and emissions of air pollutants in Beijing, at unprecedented detail and accuracy. While the project is a self-contained activity, key deliverables feed into Processes, Health and Solutions themes of the programme.

This proposal seeks Newton fund support, part of the UK's Official Development Assistance (ODA) commitment. The project will directly address ODA objectives, in the categories of (i) people (through the joint development of novel scientific approaches to the understanding of megacity air pollution), (ii) programmes (as all aspects of the project are joint UK-Chinese research endeavours) and (iii) translation (through provision of detailed air pollution source assessments, in support of assessment of health impacts and development of mitigation strategies). More generally, the project will leave a legacy of improved air pollution understanding and research capacity of the Chinese teams, and, through integration with other themes of the Megacities programme, underpin improvements in the health and welfare of the population of Beijing, and across China more widely - ultimately benefitting more than a billion people.

Planned Impact

AIRPOLL-Beijing will quantify the contribution of different industrial, commercial and societal activities to air pollution in Beijing and greatly enhance the Nested Air Quality Model Prediction and Modelling System (NAQPMS) multi-scale 3-D chemical transport model for operational prediction of air quality in Beijing.

Who will benefit:

1. Policymakers: The Chinese Department of Environmental Protection and the municipal/provincial Bureau of Environment Protection who are responsible for policy-making in air quality and for developing emergency control measure in Beijing and the surrounding region will particularly benefit from this project.
2. Business: Businesses will benefit, particularly those that are directly or indirectly affected by air pollution control measures in the Beijing region.
3. General public: There is a growing interest in China in air pollution, particularly particulate matter pollution. This is because haze, mainly caused by particulate pollution, is visible, and serious haze events cause significant health problems to vulnerable groups.

How will they benefit:

1. Policymakers: AIRPOLL-Beijing will provide an improved source apportionment of air pollutants in Beijing and an operational air quality model with online air pollutant source apportionment capacity. The former will be essential for refining the existing air quality policies at the municipal level, while the latter will benefit all levels of environmental protection bodies by predicting air quality and allowing development of emergency control measures to prevent serious haze events. AIRPOLL-Beijing will also provide a definitive example for future integrated work on air pollutant source apportionment in China, and thus improve accuracy of emission inventories and performance of air quality models, which will eventually benefit policy-making in central as well as local governments.
2. Business: The Chinese government has started a national programme to close industrial plants considered to be the highest polluters. A more accurate source-oriented apportionment of air pollutants will ensure that the high polluters are more accurately identified, which will avoid unnecessary shut-down. In addition, under unfavourable meteorological conditions, emergency control measures may be put in place; AIRPOLL-Beijing will provide scientific results and the NAQPMS air quality model to support the development of such measures. Better and more targeted emergency control measures will benefit business by reducing their impact on transportation and by protecting health of staff (so increasing productivity) and by minimizing direct cost due to unnecessary business shut-downs.
3. General public: New knowledge on haze pollution as a result of this project and the existing knowledge and experience of air pollution control from the UK will provide valuable educational information for the general public in China. The general public will also benefit directly from the improved prediction of air quality in Beijing to inform social and economic activities, such as whether or not to partake in outdoor activities.

Addressing ODA objectives:

By providing cost-effective solutions to air quality problems within China, the project will address directly poverty and development issues, and through the application of economic valuations in the Solutions Theme of this programme, will contribute to development of both effective and efficient methods of addressing air pollution. Accurate knowledge of emissions is a key factor underpinning the development of mitigation strategies which will deliver improved public health. Both the UK and Chinese research teams will benefit from their interaction and exploitation of complementary expertise. This will leave a legacy beyond the project lifetime thus increasing the research capacity of the Chinese teams and contributing to the continuous improvement of life and welfare of more than a billion people.
Description The black carbon (BC) present in Beijing has been categorised into a number of different classes according to core size and coating thickness. While this was done in a manner analogous to earlier studies (e.g. in London), a number of new habits were discovered. These different black carbon types have been linked to sources according to their composition as measured using a soot particle aerosol mass spectrometer.
Black carbon fluxes were quantified using the SP2. These indicated that the main source of BC local to the site was traffic and the ratio of this to NOx emissions was comparable to emissions ratios in the literature relevant to gasoline emissions in China. These particles were small and lightly coated, indicating that the thickly coated particles present during heavy haze events originate from outside the inner city, likely industrial or rural sources further upwind. A comparison with the emissions inventory showed that while the inventory's diurnal activity profile was correct, the emissions were an order of magnitude too high.
A new inversion method (developed by collaborators in Canada) was applied to the combination of the CMPA and SP2 instruments to probe the mixing state of black carbon particles in addition to their general habit and new quantitative measures for this were developed, based on fundamental modelling approaches. This work showed that during the winter, the mixing state of black carbon correlated with the mass ratio within the particles, which is an intuitive result for mode-based models but this relationship did not hold during the summer. This has implications for models studying the impact of BC on weather and climate.
Exploitation Route These results can be utilised by the following:
1. Those wishing to improve emission inventories for Beijing and beyond for black carbon.
2. Those seeking to apportion black carbon and particulate matter in Chinese urban environments and formulate policy
3. Those wishing to develop and test models of black carbon dynamics in polluted environments and their effects on clouds, hazes, meteorology and climate.
Sectors Environment,Transport

Title AIRPOLL IOP BC and CIMS datasets 
Description Data from the two IOPs (summer and winter) at the IAP tower site: BC flux data and FIGAERO-CIMS data. Shared with project partners and will be archived at BADC. 
Type Of Material Database/Collection of data 
Year Produced 2017 
Provided To Others? Yes  
Impact Impacts pending 
Description APHH Partnership 
Organisation Chinese Academy of Sciences
Department Institute of Atmospheric Physics (IAP)
Country China 
Sector Academic/University 
PI Contribution We worked closely with IAP during the IOPs and data analysis phases of AIRPOLL. In particular, this included sharing data and advice regarding the operation of the FIGAERO-CIMS.
Collaborator Contribution IAP provided us with access to the measurement site during the IOPs and assistance with logistics. They also provided us with data, including routine site measurements and model outputs.
Impact The IOP datasets would not have been obtained without their involvement. Publications and other outcomes are pending
Start Year 2016
Description Science on tap 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Local
Primary Audience Public/other audiences
Results and Impact Public outreach event in Beijing in coordination with RCUK. My contribution was supplying material for the presentation, assisting with questions and meeting the attendees.
Year(s) Of Engagement Activity 2017