Transportation, construction and cooking at home are among factors causing pollution both indoors and outdoors in Hanoi.
The findings were revealed by environmental experts at an air pollution workshop hosted by the Green Innovation and Development Centre (GreenID) and Ha Noi Union of Science and Technology Associations (HUSTA) on Tuesday in Hanoi.
Associate Professor Nghiem Trung Dung from Hanoi University of Science and Technology said about 40 per cent of fine particle (PM2.5 particles) emissions are from vehicles (motorcycles, cars and buses), according to research on the characterisation and source of fine particles in Hanoi.
“Hanoi has a large number of motorbikes which emit a huge amount of emissions. But who controls the quality of motorbikes?” he said, adding that a lot of out-dated vehicles are used in the city, emitting polluted air.
A good sign is that Hanoi has switched to compressed natural gas (CNG) buses on a number of routes, he said, highlighting the importance of fuel switching for the city’s bus system.
According to research by the Construction University, fine particles and superfine particles are not only present with high concentrations outdoors but also indoors.
High concentration of superfine particles indoors, according to a survey at some residential areas in Hanoi, comes from using gas stoves, microwaves and other cooking activities.
Hoang Duong Tung, chairman of Viet Nam Clean Air Network, said there are a lot of nano fine particle emission sources at home like painting houses, sweeping floors and cooking. A study at schools in Spain shows a surprising amount of emissions.
“It is necessary to invest in studies on indoors pollution. Some studies have been conducted in Vietnam but they are only small ones. We need a general large-scale study on that,” he said.
There have not been any detailed reports on the level of emission factors affecting Hanoi’s air. Emission inventories are not an easy task and are costly, Tung told Việt Nam News.
“It is time to conduct emission factor inventories in order to have proper policies. That is the responsibility of Hanoi’s authorities,” he said.
Associate Professor Nguyen Duc Luong from the Construction University said that to have a general assessment on Hanoi’s air quality, air monitoring must be conducted at different locations. Experts need to assess impacts of various emission factors on air quality such as transport, industrial activities, domestic activities, construction and meteorological conditions.
From the angle of a transport expert, Tran Danh Loi, chairman of Bridge and Road Association, HUSTA vice chairman, said trucks carrying construction materials must not be allowed to enter the inner city. Instead, construction materials should be carried in containers and these containers must leave the city at night.