Jacques Moussafir of ARIA Technologies, a French company specializing in computation of pollutant dispersion, meteorological analysis, wind, emission, and air quality modeling, said the content of dust in the air in Hanoi exceeded the allowed level many times.

He was speaking at a conference on air quality and urban traffic organized by the French Embassy and the Ministry of Natural Resources and Environment.

Traffic is the main contributor to air pollution in the city, with the content of PM10 (particles less than 10 micrometers in diameter) being four times higher than the alarm level set by the World Health Organization, Moussafir said.

PM10 are a major health concern because they can be inhaled into and accumulate in the respiratory system through normal facial masks.

According to statistics from ARIA Technologies, the annual growth of traffic vehicles in Hanoi is 12-15 percent, which contributes to the emissions of toxic substances such as sulfur dioxide and nitrogen oxide.

“Hanoi’s pollution rate is similar to that of New Delhi and Karachi – two of 10 most polluted cities in the world,” Moussafir said.

“If nothing is done, the content of dust in Hanoi will go up to 200 mg/m3, 10 times the level warned by the WHO.”

Other experts said the conference that Hanoi should work to reduce the use of personal vehicles and increase the use of public transportation.

“We need an advanced transport network, which creates less pollution than the personal vehicles we are using,” said Bernard Favre of ARIA Technologies.

Hoang Duong Tung, deputy chief of Vietnam Environment Administration, said Vietnam should follow Thailand’s Bangkok city and develop a subway and skytrain system.

Some experts said Hanoi authorities should encourage city dwellers to reduce charcoal burning cooking methods and increase the use of solar energy.

Vietnam is among the top 10 countries with the worst air pollution, according to a study released during this year’s World Economic Forum in Davos.

Vietnam's Air (Effects on Human Health) ranking was 123rd among the 132 countries surveyed.

India has the world's worst air pollution, beating China, Pakistan, Nepal and Bangladesh, according to the study.