Hanoi’s 2016 air quality was five times over the safe limit set by the World Health Organization (WHO), experts said at a seminar on pollution and public health in Hanoi on Tuesday.
The data was presented along with a report compiled by the Green Innovation and Development Centre (Green ID), a Hanoi-based sustainability advocate organization.
Based on the report, Hanoi's average air quality index was 212 - a pollution level that would require old people and those with heart and respiratory problems to stay at home. Meanwhile, the particulate matter 2.5 (PM2.5) was 50.5 micrograms per cubic meter of air, double the national standard and five times higher than WHO standards.
PM, or particulate matter, is the term for a mixture of solid particles and liquid droplets found in the air. PM2.5 particulates are as thin as 1/30 of the width of a human hair. They can easily pass through lung tissue and be absorbed into the bloodstream, causing adverse health effects.
Hanoi suffered 123 days of excessive PM2.5 levels in 2016, according to Vietnamese standards, and 282 days, according to the WHO’s air quality guidelines..
Heavy industrial zones located to the east of Hanoi and thermal power plants outside the city contributed greatly to air pollution in the capital, based on satellite data collected by the Green ID.
Calculations showed that air quality was at its worst in the first and fourth quarters of the year when Hanoi was hit by periodical winds from the northeast. According to experts, the wind carried a large amount of air pollution from the industrial areas to the capital.
Compared to Hanoi, the pollution problem in HCMC was less severe with an air quality index of 86. Last year, the southern metropolis only experienced 14 polluted days by national standards and 175 days by WHO standards.
According to Green ID, both Hanoi and HCM City were swamped in exhaust fumes emitted by a huge number of vehicles, industrial zones, construction sites, thermal power plants, waste incineration, household cooking and trans-boundary pollution.
A late 2016 survey of over 1,400 Hanoi residents, more than 86 percent of whom were under 40, found that over 70 percent of respondents claimed to have noticed respiratory problems among themselves and family members.