PM2.5 detectors or hot cakes?

Sales of PM2.5 detectors are booming in China following frequent rounds of smog in northern parts of the country.

Seeking better protection from the lung-choking smog that plagues Beijing, Wang Hongtao, a technician in his 40s, recently made an online purchase of a PM2.5 detector for more than 900 yuan ($130).

Wang said: "As smog gathers again and again in Beijing, I'm really concerned about health problems. With the PM2.5 detector, I can find out the condition of indoor air quality. Once the PM2.5 levels exceed 50 or 60, I will immediately open the air purifiers.

Chinese e-commerce giant JD.com Inc's big data show that, from Dec 16 to Dec 20, 2016, during which Beijing issued an air pollution red alert, sales of the PM2.5 detectors increased by more than 105 percent compared with 2015.

Most detectors are purchased by people in Beijing, followed by Sichuan province and Hebei province.

Beijing's Hanvon Blue Sky Technology Co Ltd, which produces one of the best-selling PM2.5 detectors in China, said its sales are on the rise.

Wu Hongjiang, co-founder of the company, said: "Booming sales of detectors show that people are more concerned about air quality and their health problems than ever before. In December 2016, we sold more than 50,000 detectors. That's the equivalent to the total number for the first three months of 2015."

Most detectors are purchased during the first quarter and fourth quarter in any particular year, during which China suffers from frequent smog.

Wu said the company provides various PM2.5 detectors, priced at hundreds of yuan on average, to monitor the air quality indoors and in vehicles.

He said: "In the future, people will be more concerned about the environment indoors and I believe the sales of the PM2.5 detectors will continue to grow in the next 10 years."

Analysts said it will take years to reduce the smog problem in China.

Chai Fahe, a researcher at the China Research Academy of Environmental Sciences, said: "As people spend more time indoors than outdoors, it is useful for them to own PM2.5 detectors to monitor the indoor air quality. But the functions of the PM2.5 detector for civil use should not be exaggerated, as it is not the same as the professional devices used by the government or institutions."