Top 6 Causes of Air Pollution in Hong Kong

There has been in recent years, a change in the causes of air pollution in Hong Kong. Before the century began, major of the pollution in Hong Kong came from the industrial areas outside Hong Kong but, in recent years, the causes of air pollution in Hong Kong has been from within Hong Kong specifically from transportation.

It’s a part of life for Hong Kong 7 million residents. Breathing polluted air that for at least a third of the year ranks below International Safety Standards on Air Quality. Many blame industrial development inside China’s booming Guangdong province for darkening their city of lights.

Hong Kong is filled with cars and people. On daily basis, citizens inhale poisonous gas. According to the Hedley Environmental Index developed by the School of Public Health of the University of Hong Kong, people were only able to breathe in clean air less than half the year in 2019.

The Roadside Air Quality Health Index in Hong Kong is more than twice as high as what the WHO considers safe. Hong Kong is more polluted than some international cities, including London, Paris and New York.

Hong Kong is ranked in the middle when Asia is concerned. Worse than Taipei but better than Chinese cities.

Hong Kong has 2 types of air pollution problems and they include local street-level pollution and smog problem. Both of these are very important and are huge problems. Local street-level pollution is mostly caused by vehicular movement especially buses using a diesel engine.

However, smog is caused by a combination of pollutants from motor vehicles, industry and power plants both in Hong Kong and in the Pearl River Delta region.

Among the various types of air pollutants, particulate matter that is thinner than our hair is the one we are very much interested in. These are particles drifting in the air that are so tiny that they may be invisible to the eye. When we talk of particulates, we refer mainly to PM 2.5 and PM 10.

Apart from suspended particulates, another common pollutant is ozone. High altitude ozone protects us. It prevents UV rays from harming our skin. At the same time, however, ground-level ozone affects our lungs and other organs.

Another pollutant is called nitrogen dioxide. They are generated by cars and power plants. Cities with a large number of automobiles or those that use large quantities of coal suffer the most from bad air pollution.

How is the Air in Hong Kong?

It’s often hard to see blue skies in Hong Kong these days. According to the Hedley Environmental Index, only 150 days in 2017 were considered to be free from pollution, or clear.

This happened when five key pollutants present in Hong Kong’s air met the World Health Organisation air quality guidelines. These include tiny particles of PM 2.5 and PM 10, sulphur dioxide, nitrogen oxides and ozone.

At the roadside area, more vehicles could be the major contributor to nitrogen oxides and PM 2.5. the particulate matter from the mainland China area, they could be from the industry, they could be from the power plant, they could be from vehicles, etc.

That is the combination of different sources to the different problems that we are looking at now.

But for those from mainland China, the air quality might not seem so bad. According to them, it’s a little worse than in Guizhou. But actually, it’s not that bad.

The air quality in Hong Kong, though bad is still preferred to mainland China since the smog is fine and the visibility is fine.

But it is not necessary comparing the air quality in Hong Kong to places like Beijing or Shanghai, more attention should be given to the health perspective. Pollutants like PM 2.5 can lead to lung diseases like asthma.

Nevertheless, the concentration of pollutants is not the only factor contributing to poor air quality. We are looking at not just the emission control policy, we also look at how the weather and climate impact air quality. Both together would drive us to have more blue skies in the future.

However, the public might not be fully aware of the health implications of air pollution. When the government talk about the air quality issue, they will mainly focus on the concentration levels. But the actual health cost is not highlighted.

The general public may not recognise the health costs could be huge. They will have a cough, they have other issues that they can feel. They can experience these symptoms but don’t recognise that is purely from air pollution.

The Hong Kong government has promised to deal with local air pollution and regional smog problems. Authorities have also introduced measures to monitor and lower vehicle emissions.

While 150 clear days may sound bad, that’s an improvement in 2016 when there were just 109 days that were considered to be clear.

Hong Kong Air Pollution Health Effects.

Air pollution has led to an additional 130,000 days of hospital beds being occupied and 2.3 million attendance in hospitals. Experts predict that air pollution increases the risk of stroke, heart diseases, lung cancer, and chronic respiratory disorders, resulting in mass deaths.

There is also low visibility, asthma and bronchial infections resulting from lack of fresh air. Coming in after high blood pressure, poor diet and smoking, air pollution already become the fourth leading cause of death in the world.

In Hong Kong, four people die every day making up an equivalent of about 1,700 deaths every year. The roads are fixed and the residential buildings are at least 40 storeys high poor ventilation has led to the increase in pollution such as dust.

The WHO released its list of top ten threats to global health in 2019, air pollution is included and considered as one of the greatest environmental risks to health by the organisation.

Top 6 Causes of Air Pollution in Hong Kong

  • Indoor Pollution
  • Smoking
  • Typhoon
  • Overcrowding
  • Transportation
  • Factories, Power Plants and Industrial Emissions

1. Indoor Pollution

Indoor pollution is one of the top 6 causes of air pollution in Hong Kong. Studies show air pollution levels inside some Hong Kong homes are worse than those found outdoors, close to the city’s busiest roads. Globally, an estimated 1.6 million people died prematurely as a result of indoor air pollution in 2017.

Some startups like Bravolinear Tech has developed an air purifying solution, it’s EnvoAir ‘Greenwall’. EnvoAir Greenwall can filter out the PM 2.5, VOC (volatile organic compounds) and some formaldehyde.

These pollutants are bad for the health. They also have an IAQ (indoor air quality) senses excessive amounts of those pollutants. The motors will turn on at a higher speed to help clean up these pollutants.

Everything is done automatically. It is a self-sustained Greenwall that you don’t have to spend time and effort on. PM 2.5 is a particulate matter consisting of fine particles of pollution and is linked to an increased risk of developing respiratory diseases.

A Hong Kong study found that 52% of the harmful PM 2.5 pollution comes from inside the home. For outdoor environments, we can hardly control them because there are many environmental factors beyond our control. But when we go indoors, we can use the filter to make air quality better.

Eco Link’s ‘NanoFIL’ air filter uses nanotechnology to achieve a high level of air filtration efficiency. The filter can kill 99% of bacteria. This filter is placed in the air conditioner to help filter the air given out by the air conditioner.

2. Smoking

Smoking is one of the top 6 causes of air pollution. Many Asian citizens are known to smoke and this impacts their health, the health of a nearby person and the health of the environment. One could imagine the emission coming from a den of smokers.

3. Typhoon

Typhoon is one of the top 6 causes of air pollution.

In addition to pollution by local contaminants, sometimes, at the eve of the typhoon, the subsidence at a storm’s outer circulation can affect convective activity in the atmosphere making it easier for suspended particulates to accumulate at ground level, thereby causing a severe case of haze.

On July 9th, 2016, under the influence of Typhoon Nepartak, the EPD recorded an AQHI of 10+, the highest reading, at all 16 monitoring stations simultaneously for the first time resulting in health risk in the “Serious” category.

Meanwhile, due to the geographical location, pollutants are also often blown to Hong Kong from the Pearl River Delta or even beyond.

Air contributes 30% of the overall influence on its air quality. Other cities in the same region have about a 20% impact. However, influences from beyond the region can be responsible for 50% or more of the overall impact.

Therefore, air quality isn’t affected by local or neighbouring sources, it can even be influenced by faraway forces.

4. Overcrowding

Overcrowding is one of the top 6 causes of air pollution in Hong Kong. Hong Kong is one of the most populated cities in the world and the more people, the more air pollution as different people have different tastes which impacts the way live their life. Overcrowding would mean more vehicles on the road causing increased emissions. It would also mean more indoor air pollution.

5. Transportation

Transportation is one of the top 6 causes of air pollution in Hong Kong. Road transport makes up about 70-80% of the air pollution occurring in China. When it comes to transportation, we all know that the bus is the source of one of the main pollutants, Nitrogen dioxide.

Although the government of the HKSAR once subsidised various bus companies to test the use of electric buses.

Due to issues such as the humid local climate, the large number of steep roads and battery efficiency, the results were unideal. Electric vehicles are not 100% clean. We are just transferring the source of pollutant emissions from the roadside to the power plants. They are not 100% clean.

But they have the advantage of alleviating roadside pollution or even eliminating it, for the time being.

In the past, we have seen unideal results, it doesn’t mean that they can’t be used. We could try testing electric vehicles on short routes that don’t cover a lot of steep terrains. The result could be drastically different. It’s not possible to replace all buses with electric buses in one go.

Some housing estates already operate their shuttle bus services using electric buses. It’s a viable option, but it hinges on careful design and application.

Some people think that it’s unsuitable to cycle in Hong Kong due to the severe air pollution along its roads. Nonetheless, a group of people have chosen to ride to work.

The amount of exhaust that you breathe in on the street or in a vehicle, when there’s a traffic jam, or even when you’re on the roadside waiting for a bus is higher than when you are cycling. If nobody promotes the use of eco-friendly forms of transportation, roadside pollution will get worse.

Vehicles cause 80-90% of roadside pollution. Urban planning in Hong Kong is predicted on motor vehicle use. Walking has been overlooked by many. However, in other parts of the world, quite a several people believe that pedestrian-friendliness is a prerequisite for a great city.

If a city is designed such that it’s easier to get from one place to another, it will be conducive to the reduction of pollutant emissions.

If shade and adequate ventilation are incorporated in architectural design, walking along the streets won’t be as gruelling as we imagine. It will encourage more citizens to walk to nearby places. Even the distance between two train stations can be covered on foot with ease.

6. Factories, Power Plants and Industrial Emissions

Factories, Power Plants and Industrial Emissions is among the top 6 causes of air pollution in Hong Kong. In the late 20th century, the pollution in Hong Kong was coming from factories, power plants and industrial emissions in mainland China, the Pearl River Delta, the so-called “factory to the world”.

Most factories around the mighty Pearl River are producing harmful pollutants often by burning fuel to generate power. A significant amount of Hong Kong’s pollution comes from the there-Guangdong province. Much of these factories are fully or partly owned by Hong Kong businesses.

These factories help ensure Shenzhen the city across from Hong Kong is covered in a nearly permanent haze of pollution. This is not so now because of the increase in cars and human beings in the city. But, a significant number of pollution still come from the factories, power plants and industrial emissions in mainland China.

In the new year, the majority of the factories in China close, the air quality in Hong Kong significantly increases by over 40 %.

Hong Kong is now responsible for more than half of its pollution with power generation among the causes of air pollution in Hong Kong. Two-thirds of Hong Kong’s electricity is generated by burning coal or oil and plans to cut emissions will ultimately make electricity more expensive.


  • How does air pollution affect Hong Kong?

Many big cities around Asia face growing problems with air pollution and this is an increasing problem for Hong Kong. A recent study put the economic cost of rising air pollution in the territory at almost 240 million dollars each year.



Editor at EnvironmentGo! | | + posts

A passion-driven environmentalist by heart. Lead content writer at EnvironmentGo.
I strive to educate the public about the environment and its problems.
It has always been about nature, we ought to protect not destroy.

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