BANGKOK — The monsoons are no longer lashing Bangkok, in that soggy season when my sons sometimes have to wade through waist-high floods to get to soccer practice.

So why did I get soaked last week, as I walked along a major avenue in the Thai capital?

The liquid, which soon flooded one of Bangkok’s busiest intersections, came from water cannons aimed at alleviating the smog that has shrouded Bangkok for weeks.

Pedestrians squealed as the plumes of water shot into the air. A vendor of coconut ice cream failed to stop his pushcart from careening into a sewer. A rat scurried, then swam.

Some of the giant hoses were connected to trucks that only contributed to the bad air afflicting Bangkok. Smoke spewed from the trucks’ exhaust pipes. Officials from Thailand’s Pollution Department estimate that vehicle emissions account for roughly 60 percent of the city’s chemical haze.

A decade ago, the Thai capital was a rarity in Asia, a place where the air had gotten cleaner largely because of a ban on the most polluting vehicles. Those days are gone.

Earlier this month, Bangkok cracked the list of the top 10 cities with the foulest air on the planet.

My sons’ school, like more than 400 across the Thai capital, will be closed on Thursday and Friday because of the smog.

Like many Asian megalopolises, which crowd the catalog of the world’s most polluted cities, Bangkok suffers from a toxic amalgam: unchecked industrialization and urbanization, a car-crazy populace and lax regulation. The burning of fallow fields and a dry season with little wind exacerbate the crisis.

Even as pollution control monitors say they are eliminating the dirtiest diesel engines, a walk on a Bangkok road can be a choking experience. City buses belch murky smoke. There are too many cars for too few roads, and too little interest in public transportation.

“In our society, a car is not just a car,” said Tara Buakamsri, the Thailand country director for Greenpeace Southeast Asia. “It’s a representation of affluence and a symbol of ownership. It will be very hard to get people to give up their cars.”

Having lived for many years in China, my family is well acquainted with dirty air.

I used to joke that we left Beijing in 2014 as pollution refugees. I had tired of strapping little face masks on our boys just so they could commute to school. On many days they couldn’t play outside at all.

The smiling panda patterns on their masks couldn’t disguise the fact that fine particulate matter is particularly corrosive for children’s lungs.

The World Health Organization says outdoor air pollution caused 4.2 million premature deaths in 2016, claiming far more lives annually than AIDS, tuberculosis and malaria combined.

We moved from Beijing to Shanghai just as the air there got worse. A couple of years ago, I didn’t realize that our dishwasher had caught fire and was sending smoke throughout the house because everything was already so murky from the pollution.

Then we moved to Bangkok. Like China, Thailand seems to be going through the same cycle: denial of a chronic problem, ineffectual solutions and then a sudden realization that the chemical miasma isn’t going to magically disappear without coordinated policies.

For years, Beijing residents spoke of fog rather than smog. When the reality finally hit, the government considered some outlandish ideas, like using giant fans to blow the pollution out of town.

Scientists agree that spraying jets of water, especially from polluting trucks, will do little to disperse Bangkok’s smog.

“There are some government agencies that want to help decrease the pollution, but maybe this is not the best thing,” said Pralong Dumrongthai, the director general of the Pollution Control Department of Thailand, in a delicate assessment of the water cannon treatment.

Nor will other unorthodox methods — like water-spraying drones that have been deployed in recent days in Bangkok — fix the chronic air problem.

Even as Prime Minister Prayuth Chan-ocha of Thailand, the head of the military junta that seized control of the country in 2014, played down Bangkok’s pollution, shopkeepers were told they could be liable to up to seven years in prison for hoarding masks.

The persistent smog has become a rallying cry for some people in Bangkok, where the aftermath of years of coups, street protests and army crackdowns has made the city seem, at least outwardly, an apolitical place.

The current junta has repeatedly postponed national elections — the latest date is set for March 24 — yet there has been little mass outrage expressed about the slow return to a nominal democracy.

Years of restrictions on free speech and assembly by the National Council for Peace and Order, as the junta is known, have had their effect, even if young people are eager to cast their first-ever ballots.