Canada wildfires renew advocacy for indoor air quality and building codes

Indoor air quality is once again a topic of discussion as Canada's wildfires blanketed New York City and the Northeast in an apocalyptic thick yellow haze this week.

Wildfires are not a new phenomenon and have disproportionately impacted the West Coast for years. But record heat, dry vegetation, and drought globally — all part of growing climate concerns — have sparked renewed interest in creating standards that ensure safer air indoors by experts.

It's something the US Environmental Protection Agency (EPA) tackled during the pandemic as indoor air quality became a concern because of the new airborne virus. The agency sets outdoor air standards that determine safe limits to exposure. In 2014, the levels were reduced to their current 12 micrograms of particles per cubic meter on average annually and no more than 35 micrograms in a 24-hour period.

But new data are showing that exposure to as little as 8 micrograms is also unsafe, according to Joseph Allen, a professor of public health and director of the healthy buildings program at Harvard University.

The World Health Organization recently upgraded its guidance to 5 micrograms on average annually. Meanwhile, the EPA has begun the process of proposing a new limit of 9 micrograms, but advocates like Allen and his colleagues say it should be 8.

What New York City experienced Wednesday was 100 times that.

"Yesterday, we saw a peak over 800 micrograms per cubic meter, which I'm still just absolutely stunned by," Allen told Yahoo Finance.

He wasn't the only one.

"Honestly, I would have never thought in my life to see something like this in New York City," said Andrea Baccarelli, chair of the Department of Environmental Health Sciences at Columbia.

Baccarelli has been studying air quality for more than two decades, and said that the impact of one day of smoke covering the city could be conveyed as it caused more heart attacks than cocaine in a day.

"This is not normal. This is...the first time, honestly, I've seen climate change with my eyes. It's a big issue, it's not minor," he added.

It's why Allen and other air quality experts harkened back to the same advice they shared during the COVID pandemic: Ensure indoor air is being filtered well to defend against harmful particles in the air.

The problem is there has never been a standard to regulate indoor air, creating inequality across buildings, Baccarelli said.

That, according to Dr. Purvi Parikh, is why individuals could smell the smoke inside buildings.

"We may want to include Hepa filtration in HVAC systems, especially in very old buildings, and have doors and windows that do not allow the smoke in. For example, many buildings in Manhattan and [the] tristate area could smell the smoke indoors...at ground level," said Parikh, an allergist and immunologist at the Allergy and Asthma Network.

The sun rises over a hazy New York City skyline as seen from Jersey City, N.J., Wednesday, June 7, 2023. Intense Canadian wildfires are blanketing the northeastern U.S. in a dystopian haze, turning the air acrid, the sky yellowish gray and prompting warnings for vulnerable populations to stay inside. (AP Photo/Seth Wenig)
The sun rises over a hazy New York City skyline as seen from Jersey City, N.J., Wednesday, June 7, 2023. (AP Photo/Seth Wenig)

Building codes and standards

The metrics used for outdoor air quality can be used as a guide for indoor air quality, too, Allen said, since no building codes and standards exist.

"We have air quality monitors in buildings across the Northeast. And in buildings with upgraded filtration... the particle levels indoors are below the health-based benchmarks [for outdoors]. In other words, the building is defending people inside from the outdoor air pollution," Allen said.

Outdoor particulates infiltrate homes and other buildings all the time. And a standard filter might be able to fight off 50% of the particles.

So during the peak in New York of 800 micrograms per cubic meter, 400 micrograms could have made it indoors.

The problem of indoor air quality isn't new. It has been relegated for years to conversations around crowded urban neighborhoods and affordable housing structures.

But the pandemic changed all that.

Or as Virginia Tech engineer Linsey Marr recently put it: "If the pandemic was whispering to us about air quality, the wildfires are screaming to us about it. Add to that concerns about gas stoves and longer allergy seasons, and it’s clear we should be on the precipice of a new public health movement to improve the air we breathe."

Allen agreed, saying, "Very few people were thinking about the filtration of their buildings prior to COVID."

The EPA has studied the issue over the years and discussed how building codes address energy efficiency rather than indoor air quality — though in some cases the two are linked. In 2017, the agency said, "Buildings in the past had high air change rates that ensured that the pollutants generated indoors were constantly diluted with outdoor air," but when the air outside is humid or extreme, it requires extra energy to condition the air indoors.

That's where upgrading filters comes in. The ideal for commercial buildings is to add HEPA filters, and MERV 13, a type of rating, filters for homes. The latter can cost as little as $25 at home improvement stores or online.

"This doesn't require a multi-million dollar overhaul of your HFAC system and the building," Allen said.

"Buildings have been overlooked for a long time as a key public health tool," he said.

Follow Anjalee on Twitter @AnjKhem

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