Monitoring China’s Traffic Pollution

ECO PHYSICS’ nCLD66 NOx-detectors implemented to monitor emissions



China’s vastly growing economy has come with the side effect of rapidly growing NOx emissions by industrial emissions, combustions and fossil fuel consumption. Anthropogenic nitrogen oxides vastly influence the tropospheric chemistry, leading to photochemical smog (Rubio et al.,2002) and the increased concentration levels of urban ozone (Melkonyan and Wagner, 2013).

The rural exodus and migration into China’s economic centres, leads to an addon of NOX-concentration into highly densely populated areas. For example, China’s capital Beijing grew from 11.8 million citizens in 2007 to 21.5 million in 2016 and 22 million in 2017 (Xinghua, 2017). In parallel, the total number of cars on the road was estimated at 5.62 million by the end of 2015. Currently the capital administration is trying to limit the vehicle number to six million (Meng Xue, 2017). Cars in the city of Beijing run at an average speed of 7.5 miles per hour (12.1 km/h).

In consequence, China’s authorities have decided to reduce the annual registration from the current 150,000 cars to 100,000 cars a year in 2018 (Xinghua, 2016). The tax will rise to 7.5% in 2017 and up to 10% in 2018 (, 2017-01-12). On the other side, development and distribution of electric and alternatively powered cars are pushed.

Researchers estimate that 2.8 million citizens endured cancer deaths and 4.3 million new cancer cases emerged during 2015 (Chen et al., 2015). In December 2016 the National People’s congress implemented China’s first tax regulation focusing on environmental protection, the EPT Law, replacing its predecessor the pollutant discharge fee (PDF), to strengthen law enforcement, effective from January 2018 (Weining Hu, 2017). China’s latest action on vehicle emission regulation is the “China 6/VI emission standard for light- and heavy-duty vehicles” (Fig.1), which the government intends to implement nationwide by 2020 (Hui He, 2016).

In order to measure the current situation and the potential progress of the newly instated counter measures, new monitoring applications are approached to give a realistic insight. Prof. Zhi Ning from the City University of Hong Kong focuses on the “on-road traffic pollution and vehicle plume measurements in Hong Kong and Beijing”. PM2.5 and ECO PHYSICS NOx-detectors (nCLD66, Fig.2) are installed in monitoring vehicles that follow a daily routine pattern, including exemplary sampling sites, to display the real atmospheric situation inside Chinas’ metropolises (Fig.3). Along with on-road and road-side measurement, the traffic volume is quantified in parallel by numerous traffic counting points.

The outcome of the daily monitoring (Fig.4) has the goal of leading to a sustainable transport policy initiative with NGOs, giving new perspectives on alternative city planning.

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