New data in a report from the UN's global health body "is enough to make all of us extremely concerned," Maria Neira, the head of the WHO's department of public health and environment, told reporters.
The problem is most acute in cities, but air in rural areas is worse than many think, WHO experts said.
Poorer countries have much dirtier air than the developed world, according to the report, but pollution "affects practically all countries in the world and all parts of society", Neira said in a statement.
"Fast action to tackle air pollution can't come soon enough," she added, urging governments to cut the number of vehicles on the road, improve waste management and promote clean cooking fuel.
Today's report was based on data collected from more than 3,000 sites across the globe.
It found that "92 percent of the world's population lives in places where air quality levels exceed WHO limits".
The data focuses on dangerous particulate matter with a diameter of less than 2.5 micrometres, or PM2.5.
PM2.5 includes toxins like sulfate and black carbon, which can penetrate deep into the lungs or cardiovascular system.
In some regions satellite data has been complemented by ground-level PM2.5 measurements, but in much of the developing world ground readings remain unavailable, forcing the WHO to rely on cruder estimates.
Despite these data gaps, Neira said the UN agency now had more information than ever about pollutants in the planet's air.
Using both satellite and ground measurements "is a big step forward towards even more confident estimates of the huge global burden", of dirty air, she added.
The WHO has estimated that more than six million deaths per year are linked to exposure to outdoor and indoor air pollution.
But indoor pollution can be equally as harmful, especially in poorer developing world homes where cooking often involves burning charcoal.
Nearly 90-percent of air pollution-related deaths occur in low and middle-income countries, the WHO said.
Southeast Asia and the Western Pacific region -- including China, Malaysia and Vietnam -- are the hardest hit, the data showed.
Using a different data set, the WHO reported in May that 80 per cent of the world's city dwellers breathe poor quality air, a figure that rose to 98 per cent in poorer countries.
Disclaimer: No Business Standard Journalist was involved in creation of this content
You’ve reached your limit of {{free_limit}} free articles this month.
Subscribe now for unlimited access.
Already subscribed? Log in
Subscribe to read the full story →
Smart Quarterly
₹900
3 Months
₹300/Month
Smart Essential
₹2,700
1 Year
₹225/Month
Super Saver
₹3,900
2 Years
₹162/Month
Renews automatically, cancel anytime
Here’s what’s included in our digital subscription plans
Exclusive premium stories online
Over 30 premium stories daily, handpicked by our editors


Complimentary Access to The New York Times
News, Games, Cooking, Audio, Wirecutter & The Athletic
Business Standard Epaper
Digital replica of our daily newspaper — with options to read, save, and share


Curated Newsletters
Insights on markets, finance, politics, tech, and more delivered to your inbox
Market Analysis & Investment Insights
In-depth market analysis & insights with access to The Smart Investor


Archives
Repository of articles and publications dating back to 1997
Ad-free Reading
Uninterrupted reading experience with no advertisements


Seamless Access Across All Devices
Access Business Standard across devices — mobile, tablet, or PC, via web or app
