Research on the distribution and emission sources of metals in PM2.5 dust in urban areas in Hanoi
Hanoi is one of the most polluted places in the country (Photo: Internet)
PM2.5 dust is a particle with a kinetic size of less than 2.5 µm, easily entering the respiratory system, so it is also called respiratory dust. Recent studies have shown that PM2.5 exposure is associated with cognitive impairment, oxidative stress, and neurodegeneration. In recent years, air quality has been studied by many agencies and organizations, especially in urban areas and big cities such as Hanoi and Ho Chi Minh City. The National Environmental Report 2015, 2016 indicates that most of our cities are facing air pollution, especially dust pollution.
To determine the contribution of emissions to dust in Hanoi, the PCA/MLR method was used by the research team. This is Principal Components Analysis (PCA), which is a statistical algorithm that uses orthogonal transformations to transform a set of data from a high-dimensional space to a new, less-dimensional space. (2 or 3 dimensions), to optimize the representation of data variability. This method is widely used to evaluate the contribution of emissions to PM2.5 dust in the world due to its simplicity and ease of use.
Some sample images at Hoang Van Thai (left image) and Xuan La (right image)
Some sample images at Co Nhue (left image) and Dong Anh (right image)
The research team gave a picture of the level of dust and 19 elements in PM2.5 dust in Dong Anh, Hoang Van Thai, Co Nhue and Xuan La areas. At the same time, the contribution of the main types of waste sources (traffic activities and industrial activities) to PM2.5 dust was estimated in some areas in Hanoi.
The topic has provided a synchronous data set long enough for research and assessment of air quality in Hanoi, including: concentration of PM2.5 dust, concentration of 19 metals of PM2.5 dust. This study is feasible for practical application to determine the contribution rate of emissions to PM2.5 dust by PCA/MLR method. However, this method requires modern analytical and monitoring equipment; and needs funding to monitor dust samples at a wide range over a long period of time.
Translated by Phuong Huyen
Link to Vietnamese version