The report was made following data from dozens of air quality monitoring stations across the world.
The report showed that up to 99% of South Asian cities; 95% of Southeast Asian cities and 89% of those in East Asia surpassed the allowed PM2.5 level
PM2.5, also described as superfine particles, is a fraction of the width of a human hair, which is released from vehicles, industry and natural sources like dust.
The World Health Organization (WHO) Air Quality Guideline recommends an annual mean exposure threshold of 10 μg/m3 to minimise health risks.
Up to 64% among more than 3,000 surveyed cities in the report exceeded the level.
In Southeast Asia, Jakarta was the most polluted city which had a PM2.5 level of 45.3 μg/m3. It was followed by Hanoi with 40.8mg/m3.
Meanwhile, HCM City was also named among the most 20 polluted cities in the region with 26.9 μg /m3.
Hanoi is now home to up to 5.8 million motorbikes and 0.7 million cars, which is among major reasons for the city’s bad air quality. Meanwhile, a range of construction projects are underway in the city have also been blamed.