Canada had North America's worst air quality in 2023 because of wildfires, report says

Last year marked the first time Canada was the most polluted country in North America since IQAir started producing its annual report in 2017. The fires played a role in U.S. air quality, as well.

Only seven counties met the World Health Organization standards for air quality last year, and during a record wildfire year, Canada had the worst air quality in North America, according to global air quality tracker IQAir.

The Swiss technology company released its annual World Air Quality Report on Tuesday with an air quality analysis from 2023. Scientists analyzed data from more than 30,000 air quality monitoring stations across 134 countries and territories to produce this year’s report, according to the international organization. 

IQAir used annual PM 2.5 particulate matter guidelines adopted by the World Health Organization as the standard for its results. PM 2.5 pollutants are fine particulate aerosol particles linked to engine exhaust, industrial processes, power generation, coal and wood burning. Natural sources of PM2.5 can include dust, wildfires and sandstorms.


According to IQAir, just seven countries met the WHO’s annual PM2.5 guidelines: Australia, Estonia, Finland, Grenada, Iceland, Mauritius and New Zealand. Only 9% of reporting cities achieved the WHO's PM2.5 guideline. 

However, not all countries and territories have publicly accessible air pollution data, the report noted. Africa remains the most underrepresented continent, with a third of the population still lacking access to air quality data. North America is the most extensively monitored region, with more than 3,200 cities reporting air quality, according to IQAir.

The organization said better reporting and monitoring is needed worldwide.

"A clean, healthy, and sustainable environment is a universal human right," IQAir CEO Frank Hammes said. "In many parts of the world, the lack of air quality data delays decisive action and perpetuates unnecessary human suffering. Air quality data saves lives. Where air quality is reported, action is taken, and air quality improves."

IQAir’s report found that much of the air quality data in Latin America and the Caribbean comes from low-cost sensors.

"Low-cost air quality monitors, sponsored and hosted by citizen scientists, researchers, community advocates, and local organizations, have proven to be valuable tools to reduce gaps in air monitoring networks across the world," the report states. 

Countries and cities with most polluted air

Central and South Asia are home to the top 10 most polluted cities in the world. 

The No. 1 country with the poorest air quality in 2023 was Bangladesh with particulate matter 15 times higher than the WHO's PM2.5 annual guideline. Pakistan, India, Tajikistan and Burkina Faso were also included in the top five most polluted countries.

Last year marked the first time Canada was the most polluted country in North America since IQAir started producing its annual report in 2017. The top 13 most polluted cities in North America were in Canada last year, according to IQAir.

Wildfires burned across Canada throughout last year, driven by warm temperatures and dry conditions that sent unhealthy air across the country, into the U.S. and around the world. In June, the smoke turned the sky in New York bright red when the city's air quality ranked the worst in the world.

By fall 2023, 6,400 wildfires in Canada burned through more than 43 million acres, according to Natural Resources Canada. The 10-year average of acres burned by wildfires in Canada is about 6.7 million acres.

How does the U.S. air quality rank?

In 2023, the air quality in the U.S. was influenced by the Canadian wildfires. The U.S. ranked 102nd out of 134 countries and territories, according to the report. The U.S. exceeded the WHO's PM2.5 guidelines by one to two times. 

According to the report, Las Vegas was the cleanest major U.S. city, and Kihei, Hawaii, was the least polluted regional city in the country. 


The most polluted major city was Columbus, Ohio. Only Beloit, Wisconsin, made it into the top 15 most polluted cities in North America. The rest of the locations were in Canada.