“Efforts to suppress open and free air pollution data, rather than address the emission sources… have created the problem,” it added.
“Great app! Thank you for your contribution to the world community for awareness of air pollution issues,” said Tam Dam on AirVisual’s Vietnam Facebook page.
Like much of Southeast Asia, Vietnam’s major cities have been plagued with smog in recent years linked to the rapid rise of coal-heavy industries, agricultural burning and vehicle emissions.
Last week the capital city’s air quality index reached above 150 — the threshold for “unhealthy” for several days in a row, prompting the government to warn vulnerable groups to stay inside.
AirVisual is one of the most widely relied on pollution monitors in the country, and also sells purifiers, monitors and face masks.
Vietnamese social media had gone into overdrive over the weekend after an influential teacher took to Facebook questioning AirVisual’s data in a post that quickly went viral.
He accused the company of publishing pollution data in order to sell its equipment, sparking thousands of negative reviews and comments on AirVisual’s Vietnam pages.
The teacher, Vu Khac Ngoc, later apologised on his Facebook page and said he hoped the app would soon return.