The air quality report in Hanoi and HCM City announced by the Vietnam Sustainable Energy Alliance (VSEA) showed Hanoi recorded 282 polluted days last year.

The report was announced at the Air Pollution: A Threat to Public Health Workshop in Hanoi on January 17.

Hanoi and HCM City polluted by exhaust gas from a huge number of vehicles

Hanoi's average air quality index was 121. When the indexes are from 101 to 200, old people and who with heart and respiratory problems should not go out too often. The particulate matter 2.5 (PM2.5) was double the national standard and five times higher than World Health Organisation standards.

Hanoi had 123 polluted days by the national standards, and 282 polluted days by WHO's standards. In the report, VSEA also pointed out that Hanoi had eight serious pollution phases from big industrial zones.

The pollution problem in HCM City is less serious with the air quality index of 86. Last year, HCM City only had 14 polluted days by national standards and 175 days by WHO's standards.

According to the research, both Hanoi and HCM City were polluted by exhaust gas from a huge number of vehicles, industrial zones, construction sites, thermal power plants, waste incineration, household cooking and trans-boundary pollution. For example, a forest fire in Indonesia in 2015 caused smog in HCM City.

People's health, especially workers and children, have been badly affected. A pollution report in 2013 also showed that urban areas with low air quality have higher rates of respiratory diseases. People with acute or chronic respiratory diseases can be found living near industrial zones.