NYC air quality has significantly deteriorated, marking a historic low for the city. Unsurprisingly, it's not only streets where the air quality is suffering, but the NYC subway system is also not immune.

In fact, recent reports indicate that the underground transportation network may be worse off than street level environments, according to research from NYU.

 Smoke from Canadian Wildfires Diminishes NYC Air Quality

On Wednesday, the NYC air quality dropped dramatically, indicating that the air wasn't just substandard but alarmingly hazardous.

This is largely attributed to the smoke from major wildfires in Canada, primarily in Quebec, carried over by wind.

The Environmental Protection Agency (EPA) has been closely tracking this airborne threat, focusing on the tiny particles that pose significant health risks.

To understand the severity, sensors across the city detected levels of particles that were 2.5 microns in diameter or smaller.

According to the state's Department of Environmental Conservation, Wednesday's levels were the highest ever recorded in NYC since records began in 1999.

Even more startling is that these levels eclipsed those recorded in San Francisco on Nov. 16, 2018, during the peak of the Northern California wildfires.

Threat to Public Health - Invisible yet Deadly

These minuscule particles, nearly 30 times smaller than the width of a human hair, are potent enough to infiltrate the lungs and bloodstream.

The EPA considers an average of thirty-five micrograms of these particles per cubic meter of air as safe for a day. However, the NYC air quality on Wednesday averaged 377 at seven stations across the city - nearly 11 times that threshold.

Subway System Suffers from Elevated Pollution Levels

Contrary to common belief, the NYC subway system is not a refuge from this poor air quality.

NYU researchers Antonio Saporito and David Luglio conducted a spot-check in lower Manhattan, and found air quality within the subway system alarmingly worse than above ground. At the Broadway-Lafayette station, the air particle count was 660 - a staggering 5,400% increase from typical city levels.

These particles, laden with potentially harmful chemicals like iron and carbon, are associated with health problems like asthma and heart attacks.

Researchers noticed that the particle count dropped when a train arrived and left due to the "piston effect," only to rise again once the train was gone.

Uncertain Future of NYC Air Quality

The future of  air quality is hard to predict. It hinges on several variables, including the progression of wildfires in Canada, the weather, and wind patterns.

Meteorologists are finding it challenging to provide accurate forecasts beyond a 48-hour window due to the complexities involved in wildfire and wind behavior.

The current pattern suggests potential improvements by early next week, but this is not set in stone.