|中等|| 53 美国 AQI||PM2.5|
|PM2.5|| 12.9 µg/m³|
|星期五, 4月 9|
中等 58 美国 AQI
|星期六, 4月 10|
优秀 43 美国 AQI
|星期日, 4月 11|
优秀 45 美国 AQI
|星期一, 4月 12|
优秀 43 美国 AQI
中等 68 美国 AQI
|星期三, 4月 14|
中等 61 美国 AQI
|星期四, 4月 15|
中等 58 美国 AQI
|星期五, 4月 16|
中等 65 美国 AQI
|星期六, 4月 17|
中等 61 美国 AQI
|星期日, 4月 18|
中等 60 美国 AQI
In comparison to other Vietnamese cities, the air quality in Da Nang is moderate with levels of PM2.5 at an approximate level of 19.9 µg/m³.The main cause of these pollutants is vehicle use, primarily motorbikes, construction work and the burning of plastic and other waste material. The burning of household waste is illegal but very difficult to actually enforce. But without a public transportation network, the residents have no other option than to use their car or motor bike to travel to work in the city.
During the last ten years, the consumption of coal has tripled and the consumption of oil has increased to 70 per cent. This situation will continue because Vietnam depends on energy produced by the coal-fired power stations. Some solar power plants have recently come online but not in any significant numbers.
The government is currently working on the introduction of a tax levied on greenhouse gases emitted by factories. The vision is to reduce the levels of nitrogen oxide and sulphur oxide by up to 20 per cent by 2025. Local governments are also looking into making operators responsible for the level of pollutants emitted by their facilities. These would include the steel, cement, chemical and electricity sectors. All machinery and equipment which is over 10 years old is now banned from being imported into the country. If these proposals come to fruition, the air quality in Da Nang will certainly improve.
As in other cities around the world, Electric Vehicles (EVs) should be encouraged as a mode of transport for the future. Subsidies could be introduced to encourage their use. A Vietnamese company recently stated to sell electric powered motorbikes but very few are seen on the city streets. Residents claim they are more expensive to operate than gasoline powered bikes and they also complain about a lack of recharging facilities offered within the city limits.
As with all forms of air pollution the fine particles, PM2.5 are particularly harmful to health. These fine particles find their way deep into the lungs where they block the flow of oxygen. Strokes, heart disease, lung cancer, chronic obstructive pulmonary diseases and respiratory infections are some of the diseases which a body becomes susceptible to. Because of its small size it is absorbed by the cells in the lungs and therefore can travel to the heart where it can cause such problems as arrhythmic heartbeats and myocardial infarctions. Air quality that is below the World Health Organisation’s recommended levels, which is currently 10 μg/m3. It is highly recommended that masks are used whist outdoors and sensitive groups should avoid prolonged exposure. Closing the windows whilst indoors will also help.
Air particles eventually fall back down to earth and can contaminate the surface of standing water. Dust-like pollution covers the leaves on the trees and can even kill young, unestablished trees by starving the leaves of sunlight.
Nitrogen Oxide and Sulphur Dioxide are the products of internal combustion engines and the burning of coal in power plants. When these chemicals mix with rain they make what is called “acid rain” which damages buildings and statues and other monuments. It also has a detrimental effect on growing crops and wildlife. Polluted air can lower the birth-rate in animals as well as producing birth defects and a lower reproductive rate.
Possibly the worst type is the PM2.5 which is a measurement of Particulate Matter suspended in the air and having a diameter of 2.5 micrometres.
Ozone or O3 is usually thought of as blocking out the harmful ultraviolet light from the sun. However Ozone can be created from Nitrogen oxides (NO) and volatile compounds found in the air. Short term exposure to Ozone reduces the function of the lungs which in turn cause chest pain. Nausea, coughing and congestion. If subject to long term exposure to Ozone permanent damage to the lungs will occur.
Nitrogen Dioxide (NO2) is most commonly produced by the internal combustion engine of which there are many in Da Nang. Lung irritation can be a sign of exposure which can lead to respiratory diseases such as influenza.
Carbon monoxide (CO) is again formed through the combustion of fossil fuels. Combustion in vehicles, the production of energy from coal-powered power stations and biomass burning are the main causes of this gas. This pollutant is dangerous because it prevents the uptake of oxygen in the blood and thus deprives the heart of it. Short term effects may produce headaches, fatigue, dizziness, nausea and vomiting.
Air quality diminishes in the dry season which occurs between January and August. The lack of rain as an air cleaner is the main reason for the increase.
As a coastal city, Da Nang experiences better air quality than other comparable cities in Vietnam. The prevailing winds from the ocean help dissipate the poor quality air. Also helped by the fact that it sits at the mouth of the Han River.
Da Nang is the largest city in central Vietnam and is one of the country’s most important ports. It is surrounded to the west by mountains and by the South China Sea to the east. These mountains sometimes prevent the spread of the dirty air causing it to appear as cloud, making the air look murky. The words “smoke” and “fog” are often combined to form the word smog. Haze is another word often associated with air pollution.
As a diversified industrial centre, Da Nang’s industries include shipbuilding, machinery, electrics, textiles and chemicals which are amongst the products made here. Most of these are produced in factories that pollute the environment with their exhausts. Many use electricity produced by coal-fired power stations. An industrial park focusing on the aviation industry is in the planning stages too.