Air Pollution in Vietnam: Analysis of the Factors of Pollution in Hanoi

Introduction

When discussing the issue of air pollution, experts, scientists, and analysts often refer to various air pollutants such as particulate matter (PM10 and PM2.5), carbon monoxide (CO), oxides of nitrogen (NOx), and others. These air pollutants have a significant negative impact on human health and the environment. Therefore, before suggesting recommendations to reduce air pollution and protect people, it is important to analyze the factors causing air pollution in Vietnam. In this essay, we will categorize these factors into two groups: natural factors and human socio-economic activities. While human socio-economic activities directly produce air pollutants, natural factors contribute to the severity of the issue indirectly.

Human Socio-economic Activities

In the context of Hanoi, human socio-economic activities refer to the social and economic development activities of the population, including population growth, construction, transportation, and production.

A. Population

Hanoi, as the capital and one of the largest cities in Vietnam, has experienced significant population growth. According to CEOWORLD Magazine (2018), Hanoi ranks 82nd among the world's top 300 most populous cities. The General Office for Population and Family Planning has predicted an average annual population growth rate of over 200,000 people, equivalent to the population of a large district. This population growth has several indirect effects on air pollution. Firstly, it leads to increased food consumption, which requires more land for production, resulting in deforestation and reduced CO absorption (Schneider et al., 2011). Secondly, population growth leads to an increased use of private vehicles, contributing to air pollution emissions (Downs, 2004). The growing population also requires more housing, which in turn requires more land and materials (Mittal, 2013). Although population growth does not directly cause air pollution, it serves as the foundation for other sources of pollution.

B. Transportation

Transportation, which involves the movement of people and goods using various vehicles such as cars, motorcycles, trains, and buses, plays a significant role in air pollution. In the case of Hanoi, we will focus on motorbikes, cars, and buses as the primary sources.

The exhaust gases emitted by internal combustion engines, especially in densely populated cities like Hanoi, contribute significantly to air pollution. These emissions include pollutants such as CO, CO2, SO2, NOx, Pb, and HC (Hoang et al., 2017). With the economic and social development, the number and density of transportation vehicles have increased rapidly. The Vietnam Environment Administration Magazine reported an increasing trend in the use of automobiles and motorbikes, with Hanoi residents relying less on walking. Hanoi currently has approximately five million motorbikes and 500,000 cars, with an additional 1,000 new cars and motorcycles registered daily. Furthermore, many old vehicles with higher emissions are still in use due to inadequate maintenance and longevity (Tài nguyên và môi trường Express). Motorcycles account for about 95% of the total vehicles in Hanoi, consuming 56% of gasoline and releasing the majority of carbon emissions, carbon monoxide, and nitrogen oxides from vehicles (Hoang, 2017). Buses also contribute to air pollution, as they often do not utilize clean fuels or environmentally friendly alternatives such as compressed natural gas (CNG) and liquefied petroleum gas (LPG), which are used in other countries. While there have been initial efforts to introduce metro and sky-train systems in certain areas of Hanoi, they are not yet widespread (Vietnam Environment Administration Magazine). In summary, emissions from transportation put a significant burden on the environment, particularly the atmosphere, resulting in severe air pollution that negatively impacts human health and the natural environment. Addressing these emissions poses a challenge for authorities and the public.

C. Processing and Production Activities

Hanoi has three large industrial parks, including Bac Thang Long, Quang Minh, and Noi Bai, which house numerous factories, in addition to smaller plants. Tài nguyên và môi trường Express and VN Green Environment Joint Stock Company have stated that emissions from these factories contribute to air pollution. The Department for Environment, Food, and Rural Affairs identified sulfur dioxide (SO2) emissions from power stations and refineries burning coal and heavy oils, as well as benzene emissions from industrial combustion and 1-3 butadiene emissions from synthetic rubber production, as major sources of pollution. According to the National Environment Report of the Ministry of Natural Resources and Environment in 2014, the electricity generation structure in Hanoi includes 52 coal-fired thermal power plants, two nuclear power plants, and several hydroelectric plants, which contribute to air pollution. Outdated technology in some factories leads to inadequate treatment of toxic emissions and waste. Additionally, the country's 50 cement factories and 40 steel processing factories are significant sources of air pollution. The steel industry alone accounts for 6% of energy consumption in the industrial sector and releases CO emissions (VN Green Environment Joint Stock Company). Iron and steel combustion also contributes to lead (Pb) emissions (Defra, What are the causes of air pollution?). Therefore, addressing air pollution requires considering the activities of these plants and proposing appropriate solutions.

D. Construction

As the population increases, infrastructure development is necessary. The government invests in roads, schools, hospitals, and citizens invest in houses and companies. The demand for land leads to deforestation, as trees play a vital role in urban heat reduction, air pollutant absorption (e.g., CO, NOx), and oxygen production (Bowling Green, Kentucky). Additionally, during construction, the use of materials such as sand, bricks, and cement, as well as the demolition of buildings, releases large amounts of dust into the air. Construction sites in cities can also contribute to dust pollution if vehicle movements are not properly managed. In conclusion, although construction activities do not directly cause severe air pollution, they are still a concern due to their potential impact.

E. Vegetation Fires

Vegetation fires significantly affect air quality in Hanoi. According to Vietnam Environment Magazine, these fires are caused by various factors, including burning agricultural land for straw and grass residue (20%), local people using fire for hunting and trapping wild animals (55%), forest product exploitation (15%), and conflicts related to forest resource exploitation (10%). After these fires, dust and smoke are carried by the wind, leading to air pollution. The incidents of post-harvest haze are becoming more frequent.

To summarize, in terms of human socio-economic activities, the main direct sources of air pollution in Hanoi are transportation, processing and manufacturing activities, construction, and vegetation fires. These activities release a significant amount of pollutants into the air, presenting a pressing societal problem. However, there are also natural factors that contribute to air pollution in Hanoi, albeit to a lesser extent.

Natural Factors

When referring to natural factors, we consider natural phenomena such as fires, volcanic eruptions, typhoons, earthquakes, etc. These events release a substantial amount of dust into the air, contributing to air pollution. However, in the case of Hanoi, we will focus on indirect sources: monsoons and fog.

A. Monsoons

Hanoi, located in northern Vietnam, is influenced by monsoons. During the monsoon season, strong winds and foggy periods occur. The wind carries dust, pollen, and dirt, spreading them throughout the area. Mr. Mai Trong Thai, Director General of the Hanoi Environmental Protection Agency, stated that the effect of the Northeast Monsoon still covers Hanoi in the first three months of the year. Monsoons can bring dust from distant locations and combine it with the dry, cold climate and high atmospheric pressure, resulting in high levels of PM2.5 in the air. Furthermore, during the Tet holiday, smoke and dust from burning votive papers contribute to the worsening air pollution through wind dispersal.

B. Fog

According to National Geographic, fog forms when water vapor condenses around microscopic solid particles in the air. Fog reduces visibility, solar irradiance, and can contribute to the dissolution of air pollution (Bendix et al., 2011). When fog occurs, there is a higher concentration of dust in the air. Dust from burning waste, exhaust emissions from factories and transportation, etc., becomes trapped in the fog, leading to dense fog and elevated levels of PM2.5. Consequently, on foggy days, the Air Quality Index (AQI) in Hanoi reaches unhealthy and very unhealthy levels. The US Environmental Protection Agency (EPA) has defined six levels of AQI based on the PM2.5 index: good, moderate, unhealthy for sensitive groups, unhealthy, very unhealthy, and hazardous. The Hanoi Environmental Protection Agency (EPA) reported that from March 10th to March 16th, the AQI at various monitoring sites in the city, such as Trung Yen 3, Kim Lien, My Dinh, Tan Mai, and Tay Mo, remained at an unhealthy level. At Trung Yen, AQI was unhealthy for three days, accounting for 42% of the period, very unhealthy for 28.6%, and moderate for 28.6%. At Kim Lien, My Dinh, and Tan Mai, the AQI ranged from good to moderate, accounting for 14.2%-28.6% (Hanoi Environmental Protection Agency).

To sum up, natural sources, including fog and monsoons, contribute to air pollution in Hanoi, but their impact is relatively small compared to human socio-economic activities (Department for Environment, Food, and Rural Affairs). Nevertheless, when assessing and addressing the problem, it is necessary to consider the complete picture and tackle the root causes.

Conclusion

In conclusion, air pollution in Hanoi is a critical issue that affects both human health and the environment. Various factors contribute to this problem, with human socio-economic activities being the primary drivers. These activities include population growth, transportation, processing and production activities, construction, and vegetation fires. The emissions from these activities release a significant amount of pollutants into the air, leading to detrimental effects. Additionally, natural factors, such as monsoons and fog, indirectly contribute to air pollution in Hanoi, although to a lesser extent. To mitigate air pollution effectively, comprehensive measures addressing both human activities and natural factors need to be implemented. This will require the collective efforts of authorities, industries, and the public to adopt sustainable practices, improve transportation systems, enhance industrial processes, and preserve the natural environment. By taking decisive action, Hanoi can improve air quality and safeguard the health and well-being of its residents.

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