Canned air and water-spraying drones: Smog remedies


HONG KONG • As billions of people in Asia choke under polluted skies, authorities have turned to water-dispersing drones and outdoor air purifiers to improve air quality, while companies have tried to cash in by selling everything from canned air to lung-purifying teas.

Around 92% of the population in the Asia-Pacific region are exposed to levels of air pollution that pose a significant risk to their health, according to United Nations Environment Programme.

Here is a look at some of the ways those living under the haze try to limit its effects.

Spraying Water
As public anger rises over toxic air, authorities have turned to spraying water, which is thought to stick to pollutants and carry them to the ground.

But tools such as water cannons have been criticised as having little effect and being a “band-aid” solution that distracts from root causes.

New Delhi — the world’s most polluted major city — tried in 2017 to use helicopters to sprinkle water over the city, but the choppers were not able to fly due to low visibility caused by smog.

In Bangkok, the government tried a raft of measures to combat a murky haze that blanketed the city for weeks in January, including spraying overpasses with water, cloud seeding and even deploying a fleet of water dispersing drones.

An attempt by South Korea to create artificial rain to tackle air pollution in January failed, after an aircraft sent to seed clouds with silver iodide only produced several minutes of misty rain.

Outdoor Air Purifiers
The northern Chinese city of Xi’an is experimenting with a giant air purifier the size of an industrial smokestack which can reduce PM2.5 concentration by 15% within 10 sq km, according to researchers.

Hong Kong this year opened a 3.7km tunnel equipped with an air purification system touted as the largest of its kind in the world in terms of volume of air handled — 5.4 million cu m of vehicle exhaust every hour. The government said it will be able to remove at least 80% of harmful particulates and nitrogen dioxide using large fans which suck exhaust into air purification plants in three ventilation buildings along the tunnel.

New Delhi last year announced a plan to instal huge air purifiers at traffic intersections and mount air filters on the roofs of buses that trap pollutants as they move, according to Hindustan Times.

Commercial Remedies
Although experts said residents in smoggy cities are unlikely to see health effects from breathing bottled air, that hasn’t stopped entrepreneurs from selling them canisters of the stuff from New Zealand, Canada, Australia and Switzerland.

For about US$22 (RM89.76), consumers can order an eight-litre can of Banff Air from the popular tourist spot in Canada, or pay US$125 for a jar of air from the British countryside.

In China, “anti-smog” teas are promoted by vendors as a way to clean the lungs, while Mongolian residents drink “oxygen cocktails” — made by spraying oxygen into glasses of juice using machines or cans of air. Advertisements boast that “drinking just one oxygen cocktail is equal to a three-hour walk in a lush forest”, despite no scientific evidence they protect from pollution. — AFP