More affordable sensors making it easier to detect air pollution

​​​​​​Rampant air pollution has been plaguing Dhaka for some time now. 

While more expensive sensors used by government regular can cost between $20,000 and $30,000 US for each monitoring station, Glory Dolphin Hammes, North American CEO of IQAir is selling air quality monitoring products and managing a platform using regulatory and low-cost sensors around the world.

The data gets verified and feeds into real-time online reports as well as those yearly pollution rankings, reports CBC.

Cheaper sensors, she says, provide broader coverage and give people actionable information.

"They are given the power of choice to mask up or to do other means to mitigate the air quality that they're breathing," Hammes told CBC News from Los Angeles.

In Dhaka, Bangladesh, the air quality on some days can get downright dangerous. Levels of PM2.5, fine particulate matter linked to heart, lung and cognitive issues, often exceed safe health standards.

"In Bangladesh, we have a national standard, it's about 65 micrograms per cubic [µg/m3] for 24 hours," said Riaz Hossain Khan, assistant scientist at BRAC University in Dhaka. But during the dry season, it's much worse.

"If you measure something during December or January, these months, you'll find close to 250 or 300."

Experts say that's resulting in kids struggling to breathe on smoggy days, and more middle-aged people developing cough-variant asthma, which can be persistent and chronic.

While the daily concentrations are bad, the picture for the whole year is no better. Bangladesh topped recent global rankings by IQAir, an air quality technology company, for the highest annual average concentrations of PM2.5, at 79.9 µg/m3. The World Health Organization's guidelines recommends five µg/m3.

Up to gold standards

Progress is also being made on bringing sensors up to a higher standard, according to Olorunfemi Adetona, who researches pollutant exposure and health effects at Ohio State University.

"The Environmental Protection Agency has tried to calibrate this instrumentation against the more gold standard measurements," Adetona explained. The EPA has developed methods to integrate the data from the low-cost sensors with that from the more expensive ones.

But Dhaka is complex, reminds Zahidul Quayyum, a colleague of Khan's and a health economics expert at BRAC University.

"You cannot clearly distinguish between some of these purely residential areas and [others]," Quayyum told CBC News from Dhaka, explaining that the city's urban planning is outpaced by its growth. A weave of informal industry, traffic and residential environments make regulating air pollution complicated.

But change has happened, at least in one of the most publicized sources of air pollution: brick kilns. Many of them operate informally and illegally.

"They made some changes in the policy, which took the brick kilns out of the city," Quayyum noted. But politics and business don't always get along, he says, and when asked whether data is leading to better public health policy, Quayyum is practical.

"Yes, to some extent. But more needs to be done."