New Yorkers are getting a taste of what it's like to live in the pollution of Delhi, Doha, and Shanghai

• New York City's air is abysmal this week because of smoke from Canadian wildfires.
• Hazy skies are a shock to New York and other eastern locales but poor air is common in many cities.

As a former New York City resident, I'm always curious about what's going on there. This week I didn't expect my texts to be about air quality.

Coworkers, friends, and family members in various locales up and down the East Coast texted me about the terrible smoke blanketing their neighborhoods, with a cousin saying he'd had some trouble breathing. Another family member said Manhattan looked apocalyptic.

For the past few days, New York City's air has appeared dirtier than the bottom of a subway track. The foul air from massive Canadian wildfires is expected to linger through at least Saturday.

As shocked as New Yorkers — and people in other big cities from Detroit to Washington, DC — might be to barely be able to make out their skylines, this is nothing new for many people who live in other parts of the world.

Lahore, Pakistan; Hotan, China; and Bhiwadi, India, had the worst air quality in the world in 2022, according to data from IQ Air. My colleague Spriha Srivastava wrote that New York's suffocating smog reminds her of growing up in Delhi.

Indeed, New York City has found itself atop the rankings — and above all of the perennial offenders — for having the worst air quality and being hazardous to breathe. New York Mayor Eric Adams said that by Wednesday afternoon the air quality index hit 484, out of a scale of 500. As of midday Thursday, it's around 180 — still not great.

New Yorkers and others are getting a taste of what it can be like to live in Doha, Qatar, and Shanghai, where at least air pollution appears to be improving.

In many developed economies, expectations about clean air are baked in. But that wasn't always the case, even in the US. Landmark legislation like the Clean Air Act, signed into law by President Nixon in 1970 and beefed up in 1990, acted like a giant air filter for the nation.

Today, in many global cities where the air quality is poor, the focus is often on building economies to lift people out of poverty.

"They're in a period of rapid economic growth," Robert Kremens, a physicist who studies wildfires, told Insider. "They sacrifice air quality over human health."

He said those decisions are often understandable because the focus is on ensuring citizens aren't going hungry, for example.

Yet there are consequences from the pollution as well. A study published last year found 86% of people living in the world's urban spaces encounter air pollution that's more than seven times above guidelines put out by the World Health Organization back in 2005.

Cleaner air is something the US now takes for granted — even out west where smoke from wildfires is far more common. Kremens, who is with the Chester F. Carlson Center for Imaging Science at Rochester Institute of Technology, said the US made a decision decades ago to make cleaner air a priority. That meant a big drop in pollution from industrial smokestacks and tailpipes.

That was quite a change from the years before the federal government had the authority to regulate what America was sending into the sky. In 1948, for example, over the course of five days in Donora, Pennsylvania, 20 people died and thousands more were made sick by air pollution that spewed from a factory. It was incidents like this and seminal works like Rachel Carson's 1962 book "Silent Spring" on the effects of insecticides that propelled a nascent environmental movement.

When the first Earth Day took place in April 1970, air pollution was a major problem in most US cities. In 1969, a river in Cleveland topped with industrial runoff caught fire, something that had happened at least a dozen times before. Almost one in 10 Americans took part in demonstrations or activities on the first Earth Day, and those participants sought something in particular: government action.

Those actions have since made such a difference that many of us are now shocked by what poor air quality looks like.

"I'm going out to LA tomorrow. It's not red anymore. It used to be red when we went there," Kremens said this week from his office in Rochester, New York. "This is a societal decision, where we're going to clean up the air and the water." Kremens pointed to the Clean Air Act and the Clean Water Act as examples for what can be done when enough attention is paid to an environmental challenge.

These advance are likely why the recent haze choking so many eastern cities has been so jarring, even for Kremens, who has gone around the world studying — and fighting — fires for more than 20 years.

"I go outside and it smells like Montana," he said. "I have so many pictures on my wall that look like here now, but they're from Utah and Montana and places I've worked out west."

I'm looking forward to another batch of photos from friends and family in eastern cities — pictures showing clear skies.