VietNamNet Bridge – The Director of the Research Centre for Environmental Monitoring and Modeling under the Ha Noi University of Science, Hoang Xuan Co, told Lao Dong (Labour) Newspaper about Ha Noi’s air quality following recent reports of mercury pollution in the air in the capital city.

People are worried after receiving information relating to mercury pollution in the air in Ha Noi. As a researcher in the field of air quality, what do you think?

It is normal for mercury to exist in the air. It has existed for a long time and people still get exposed to it. The main concern is whether there is any new source of mercury pollution, and according to my assessment, there is no new source of mercury pollution. So people should not panic.

It requires specific research and measurements to conclude exactly whether mercury entered the air in the city. If the level of mercury in the air exceeds the standard amount, it will be considered harmful. However, it is not easy to measure the level of mercury in the air, particularly when it is at a low rate.     

According to your research, is it possible to conclude that the air in Ha Noi is contaminated?

We used to calculate measurements on a trial basis contamination index in Ha Noi, based on figures from 2004 to 2008 following the calculation methods of China. Accordingly, we calculated the pollution index every day and then classified the index into different categories, including very good air, good air, slightly contaminated air, etc. Results showed that the air quality deteriorated gradually each year from very good to good with the appearance of slightly contaminated air. There were times when the air was polluted, but it was not significant.

Regarding the question of whether the air in Ha Noi is polluted or not, there is no basis to conclude that because Viet Nam is still unable to issue specific regulations on air pollution like other countries. For example, in Japan, a city will be declared as slightly or seriously contaminated if the air pollution rate in that city is close to or exceeds 2 per cent, respectively. Meanwhile, in Viet Nam, there are different figures and data, so it is difficult to confirm whether the air is polluted.  

We cannot say that the air in Ha Noi is polluted without scientific basis (including full data and figures) and a legal basis (air quality standards set by the State).

Do you have any suggestions relating to the installment of air monitoring stations in Ha Noi?

In my opinion, having many air monitoring stations is not necessarily good. The main point is that the installment of air monitoring stations should meet our real demand and purpose. We should have a clear plan and purpose before installing any air monitoring stations. We should choose locations where the air quality can represent the air quality of the whole city. For example, air monitoring stations can be installed near My Dinh stadium in Cau Giay District, in Gia Lam District and in Ba Vi District. According to my calculation, air monitoring stations in these three areas can measure air quality that is specific to Ha Noi.

We can also add two more stations in Ha Dong and Soc Son districts.

VNS