Only 13 of the world’s countries and territories had “healthy” air quality last year, according to a new report, as air pollution surged to alarming levels in 2022.

The report by IQAir, a company that tracks air quality worldwide, found that average annual air pollution in roughly 90% of the countries and territories analyzed exceeded the World Health Organization’s air quality guidelines, which are designed to help governments craft regulations to protect public health.

IQAir analyzed average air quality from 131 countries and territories, and found that just six countries — Australia, Estonia, Finland, Grenada, Iceland and New Zealand — and seven territories in the Pacific and Caribbean, including Guam and Puerto Rico, met the WHO air quality guidelines, which call for an average air pollution level of 5 micrograms per cubic meter or less.

Seven countries – Chad, Iraq, Pakistan, Bahrain, Bangladesh, Burkina Faso, Kuwait and India – had poor air quality that far exceeded the WHO guidelines with average air pollution over 50 micrograms per cubic meter.

The study looked specifically at fine particulate matter, or PM2.5, which is the tiniest pollutant but also the most dangerous. When inhaled, the PM2.5 travels deep into lung tissue where it can enter the bloodstream. It comes from sources like the combustion of fossil fuels, dust storms and wildfires, and has been linked to a number of health problems including asthma, heart disease and other respiratory illnesses.

WHO tightened its annual air pollution guidelines in September 2021, cutting the acceptable amount of fine particulate matter from 10 to 5 micrograms per cubic meter.

Millions of people die each year from air pollution-related health issues. In 2016, around 4.2 million premature deaths were associated with fine particulate matter, according to the UN agency. If the latest guidelines had been applied back then, WHO found there could have been nearly 3.3 million fewer pollution-related deaths.

The report also continues to highlight a worrying inequality: the lack of monitoring stations in developing countries in Africa, South America and the Middle East, which results in a dearth of air quality data in those regions.

Although Africa saw improvement in the number of countries included in this year’s report compared with 2021, the continent still largely remains the most underrepresented. According to IQAir, only 19 out of 54 African countries had sufficient data available from their monitoring stations.

Glory Dolphin Hammes, CEO of IQAir North America, said that each time it adds a new country that once lacked air quality data – as it did with Chad in 2021 – those countries inevitably wind up at the top of the most-polluted list.

“If you look at what’s called satellite or modeled data, Africa is supposed to be probably the most polluted continent on the planet, but we don’t have enough data,” Hammes told CNN. “What that means is there’s a whole lot more data that’s needed in order for us to truly determine what are the most polluted countries and cities in the world.”

But one of the biggest barriers right now, she said, is “the way that governments currently monitor air quality.” Hammes said most governments tend to invest in instruments that fail to accurately measure fine particulate matter in the air.

In the United States, the report found air pollution improved significantly last year compared with 2021 due to a relatively mild wildfire season.

Coffeyville, Kansas, had the worst air quality in the US last year, which IQAir attributed to a nearby oil refinery. Columbus, Ohio; Atlanta and Chicago topped the list of major US cities with the worst air quality, though the researchers also noted that California was home to 10 of the 15 worst major cities for air pollution, including Los Angeles and Sacramento.

Around the world, researchers said, the main sources of air pollution last year were wildfires and the burning of fossil fuels for transportation and energy production, which wreaks havoc on the most vulnerable and marginalized communities.

“This is literally about how we as a planet are continuing this unhealthy relationship with fossil fuels,” Hammes said. “We are still dependent on fossil fuels and fossil fuels are responsible for the majority of air pollution that we encounter on this planet.”

China, which had for decades been near the top of the list for the worst air pollution, continued to show improved air quality in 2022. Nearly 64% of the 524 cities analyzed in mainland China saw reductions in annual PM2.5.

Still, IQAir notes that the country’s coal usage continues to be a major climate and environmental concern, and that despite the improvement, none of the Chinese cities actually met the annual WHO guidelines.

Climate change-fueled wildfires, Hammes said, also play a significant role in worsening air quality, especially in the US. The report notes that wildfires in recent years have been rapidly erasing air quality improvements that the US has made over the past decade.

“Wildfires are very much so a global warming issue, and it is creating essentially unsafe conditions,” Hammes said.

Hammes said countries must learn from each other, noting that the countries with best air quality, for example, are the ones taking on specific actions to transition away from polluting industries and into greener forms of energy, such as solar and wind.

She adds it is also important to expand air quality monitoring networks, especially in predominantly disadvantaged regions. For instance, despite Russia’s ongoing war in Ukraine, the IQAir report shows that Ukraine expanded air monitoring networks, collecting data from nearly triple the number of cities in 2022 than in 2021.

“What we’ve learned is that what gets measured gets done,” Hammes said. “We need to collect more data. We need to inform folks of this information, and it does need to be free and available, so that they can make more informed choices.”