Airborne particles have a major impact on our planet’s atmosphere and the megacities of China – vast swathes of humanity living, working and breathing together in cities of up to 26 million inhabitants. Although air quality in Chinese cities has been steadily improving, the levels remain above WHO guidelines. Thus air pollution and its ensuing health issues are of paramount importance to the leaders of China’s biggest cities.
“High levels of air pollution pose a serious health risk to inhabitants of many Chinese cities. We confirmed that Beijing’s air quality has improved significantly in recent years, but air pollution levels are still well above the WHO guidelines, leading to poor health and wellbeing for over 20 million people.
“Our measurement work in Beijing has given us a much greater understanding of air pollutants in Beijing – where the pollution is coming from and how much there is. This, in turn, allows us to make recommendations to policy makers and help them make the decisions that will reduce air pollution levels in Beijing and other cities across China.”
The scientists used the Institute of Atmospheric Physics’ (IAP) 325-meter meteorological tower to measure how pollution composition and levels change at different heights above the city – using multiple atmospheric measurement and analysis strategies to determine where the pollution is coming from and how much there is.
The APHH team developed a range of state-of-the-art scientific approaches to record emissions - integrating these to produce new modelling tools for use in policy development.
Receptor modelling allowed the scientists to record detailed composition measurements and infer pollutant sources from their chemical signatures - combining world-leading British and Chinese capability. Flux measurements recorded the total release of pollutants from all sources, providing a key metric to refine emission inventories that combines near-ground measurements, ground-based observations and fluxes derived from satellite observations.
A novel sensor network deployed around central Beijing measured pollutant fields to create a 3D spatial analysis of air pollution, whilst novel emissions inventories allowed prediction air pollutant emissions from all sources, enhancing existing capability. New online modelling tools enabled integration of emissions, atmospheric processing and meteorology to predict primary and secondary pollutant concentration fields.
Professor Zongbo Shi, from the University of Birmingham, is the science co-ordinator of APHH-Beijing.
“Our research programme generated a huge dataset on particulate and gaseous pollutants, health outcomes, social, economic and behavioural information, collected simultaneously in an area close to the city centre and in a rural location during two intensive campaigns.
“Analysing this rich dataset allows us to better understand how emissions, chemistry and meteorology interact to determine pollution levels during winter haze events and summer smogs and gauge their impact on physical and mental health.
“The programme has enhanced UK-China collaboration, trained the next generation of scientists, and created a legacy of enhanced scientific understanding for the future that will help citizens to take individual actions to improve their day-to-day lives.”
The Shanghai skyline covered in a thick smog. Image credit: Unsplash.
Whilst Birmingham environmental scientists played a pivotal role in the programme, the project’s greatest strength came from the close partnership between Chinese and British scientists. More than 150 experts from 11 Chinese and 18 British research institutions worked together as equal partners on challenges of global significance.
The UK-China team of scientists developed a range of eight policy suggestions, based on the research, which could be taken up by policymakers. These ranged from reducing emissions of particulate matter, VOCs and black carbon from outside Beijing city centre to combating the impact of air pollution on mental health by advocating the use of face-masks and air purifiers during pollution events for people with pre-existing conditions, the elderly and the young.
“APHH-Beijing has significantly advanced our understanding of air pollution in Beijing, supporting policy development to provide widespread human health improvements across a sizable number of people living and working in Beijing,” commented Professor Roy Harrison.
“We’ve engaged with policymakers from the beginning of the programme and some of our research outcomes, such as the updated high resolution emission inventories and air pollutant emissions from residential sources, have already contributed changes in environmental policy.”
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