Chinese researchers have developed a mobile device that can trace volatile organic compounds (VOCs), a key source of air pollution, as the country with the world's largest carbon emissions continues its battle to bring back blue skies.
The equipment, comprising a vibration-resistant sensor, a positioning signal receiver and geographic information system, can be attached to vehicles to trace the distribution of VOCs in cities.
VOCs are important precursors of ozone (O3) and PM2.5 matter – the most harmful small particles and a key indicator of air pollution.
It is difficult to trace them with conventional laboratory testing equipment, at a fixed site or with portable sensors, because their distribution and emission times are complicated, according to a statement from the Chinese Academy of Sciences’ Hefei Institutes of Physical Science, whose researchers conducted the study.
The data obtained by the device will be used to image the aerial distribution of VOCs in real time while the vehicle platform is moving.
It is currently being used in several places, including Shanghai, Jiangsu province and Macau, the statement said.
Following the Trump Administration’s withdrawal from the Paris Agreement in 2017, China was expected to take the lead on the environment given its role as the world's top carbon emitter and second-largest economy.
In a meeting with French President Emmanuel Macron in Beijing late last year, Chinese President Xi Jinping said China would push forward on international cooperation with more nations in the fight against climate change.
But this year has proved challenging when it comes to environmental protection after the economy was hit hard by the Covid-19 pandemic and escalating US-China tensions. Beijing’s top agenda has been to ensure employment and stabilise trade.
At the Two Sessions parliamentary meetings in May, Chinese environment minister Huang Runqiu called the year “special” but promised to keep going with the green agenda.
There was an environmental upside to the pandemic and associated lockdowns – air quality did improve.
From January to June, Beijing recorded 29 days with a PM2.5 level at 50 or below – rated as “good” – compared to 21 days in the same period last year.
However, the duration of healthy O3 levels, which accumulated for 127 days, were the same as last year.
Huang said that in the short-to-mid term China would reduce its energy consumption by applying more clean heating systems in winter and reducing emissions from diesel-fuelled lorries.
A paper on the VOC research was published online in May by the Environmental Pollution journal online in May.
This article was first published in South China Morning Post.