Quantitative Attribution of Secondary Organic Aerosol in Beijing to its Precursors

Breathing particles in polluted air leads to the worsening of many health conditions and ultimately to premature death. The atmosphere of Beijing is well known for its very high concentrations of airborne particles and there is an urgent need for further control measures. A large proportion of those particles (referred to as "haze") are not emitted directly into the atmosphere but form within the atmosphere from chemical reactions of gases and vapours. This project is concerned with finding out which gases and vapours emitted into the atmosphere from road traffic, fuel burning, refuse incineration and many other sources are responsible for the formation of particles within the atmosphere of Beijing and the amount which they contribute to the concentration of particles. The scientific approach is to fill a reaction chamber with the vapours of a single chemical compound and let them undergo chemical reactions which lead to particle formation. The particles formed are then subject to very detailed chemical analysis and constituent molecules are identified which are characteristic of the compounds originally put into the chamber. Then, by making measurements of the same compound in the atmosphere, it is possible to estimate how much of the particles arise from the reaction of a particular gas. Control policies can then be formulated to reduce the emissions of those gases most responsible for particle formation.

This project will add substantially to the outputs of the APHH-Beijing group of projects and specifically to the AIRPOLL-Beijing project. AIRPOLL-Beijing is quantifying the contribution of different industrial, commercial and societal activities to air pollution in Beijing and aims to greatly enhance the nested air quality prediction and modelling system (NAQPMS) Multi-Scale 3D Chemical Transport Model for operational prediction of air quality in Beijing.

Those who will benefit are as follows:
(1) Policymakers: The Chinese Department of Environmental Protection and the Municipal/Provisional Bureau of Environment Protection who are responsible for policymaking and air quality of the development emergency control measures 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 huge interest in China in air pollution, particularly the haze pollution that afflicts Beijing. This is because haze, caused mainly by particulate matter pollution, is visible, and serious haze events cause significant health problems to vulnerable groups.

How they will 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.