Air quality in Hong Kong

How bad is the air quality in Hong Kong?

The quality of air in Hong Kong is considered a serious matter. For over 30 per cent of the year, visibility is less than 8 kilometres. Haze is often seen hanging over the city which can last for several days, depending on the direction of the prevailing winds. Because of this reduction in air quality, cases of bronchial infections and asthma has risen sharply. The average air quality index for 2019 was 96 US AQI with a PM2.5 of 33.5 µg/m³ together with significant amounts of PM10, O₃, NO₂, SO₂ and CO, according to data published on the IQAir website. The World Health Organisation (WHO) recommend PM2.5 levels to be no higher than 10 µg/m3. The quality of air is monitored by 11 stations and 3 roadside ones. Readings are taken on an hourly basis to measure the suspended fine particulate matter which is proven to be most hazardous to health.

Ground-level ozone (O₃) is formed when VOCs (Volatile Organic Compounds) and oxides of nitrogen (NO_x) react with ultraviolet light. The main source of these pollutants comes from vehicle emissions of which there is plenty throughout the city. Ground-level ozone is at its height during the afternoon when the sun’s rays are the strongest and even more so during the summer months. It is reported that the ozone level has increased by 21 per cent when compared to figures from 2019. Annual figures released by the monitoring network show ozone concentrations of 58 µg/m³ which is the same as it was in 2017 but the worst recorded since 2011. Data is collected from 23 monitors situated in Hong Kong, Macau and Guangdong as part of a joint initiative to significantly improve the quality of air within the region.

On 3rd September 2020, air pollution was recorded as being at the “serious” level in parts of Hong Kong. This is partly due to the hottest summer ever recorded since records began in 1884

Why is Hong Kong air quality so bad?

Over 50 per cent of the polluted air in Hong Kong comes from local sources. Vehicles on the city’s streets with their idling engines and the fumes emitted by marine vessels. There are an estimated 275 vehicles per kilometre congesting the roads in Hong Kong which are known as having the highest density of vehicles anywhere in the world. Another contributing factor is the emissions from the coal-fired power stations. External factors also come into play with the substantial amount of polluted air which drifts down from neighbouring China. Emissions from the heart of China’s manufacturing industries in the Pearl River Delta caused by thousands of factories are carried by the prevailing winds in the direction of Hong Kong. Two other major contributors are the two largest producers of electricity, namely H K Electric holdings and China Light and Power, between them they emit more than 75,000 tonnes of Carbon Dioxide (CO₂) into the atmosphere.

PM2.5 particulate matter is a complex mixture of many dangerous pollutants such as black carbon (BC), smoke, nitrates, dust, sulphates and even rubber. These microscopic particles bypass the body’s defence mechanism and become deeply lodged in the alveoli at the base of the bronchial tubes. Because of their size, they can easily pass through body tissue and eventually enter the heart. Once inside the heart they can lead to irregular heartbeats, nonfatal heart attacks and premature death of those suffering from pre-existing conditions.

Most of the sulphur dioxide (SO₂) comes from vehicle emissions and the burning of fossil fuels. As well as aggravating health problems it also mixes with air and rain to produce sulphuric acid or acid rain. This can be damaging to all buildings and statues that it falls on as well as having a bad effect on any plants or trees. Crops suffer due to the effects of acid rain.

Even young healthy adults can be affected by poor quality air. The eyes, nose and throat can become irritated which then leads to coughing, tightness of the chest and often shortness of breath.

Figures have been taken from 3 roadside monitoring station and a pattern has been found that reveals very high concentrations of traffic-derived pollutants, namely nitrogen dioxide (NO₂). The patterns follow both daily and weekly cycles. Seasonal changes are also noted duethe direction of the prevailing winds.

Container ships are the largest source of air pollution in and around Hong Kong. They produce most of the sulphur dioxide (SO₂) nitrous oxides and PM2.5 particulates that are released daily into the environment.

How can Hong Kong improve the quality of its air?

The Environmental Protection Department (EDP) was established to help find a solution to the poor air quality and to assist in the provision of long-term acceptable levels of clean air.

A charitable organisation known as “Clean the Air “has been established with a goal of improving the air quality in Hong Kong. Voluntary phasing out of older diesel-fuelled vehicles has not been successful and further steps are needed to make this happen through new rules and regulations. Out of the 80,000 government operated diesel vehicles, 76,000 have already been taken out of service and the remaining 4,000 are expected to be retired within the next year. The emissions of PM2.5 particulates from power stations need to be reduced. Within the coming year, it is hoped that the coal-fired power stations will convert to the use of natural gas. The use of energy in both public and private buildings needs to be addressed with energy saving and efficient use of power. When cars are stopped at junctions, it is now required that the engines are turned off and not left idling. An idling engine produces large amounts of pollutant which discharge into the immediate area. This mandate was introduced in late 2007 which gave the patrols the power to impose a fixed penalty of HK$320 for the violation of the idling rule. It is now illegal for any driver to get out of their vehicle whilst the engines is still running. The law now prohibits the loitering of taxis and minibuses and they are not encouraged to loiter whilst waiting for clients. Mobile monitoring stations near busy junctions record this huge increase in pollution. Engine Idling Patrols have been established to remind motorists to switch their engines off whilst waiting. Marine vehicles are not exempt from scrutiny either, but more still needs to be done to establish a Clean Port Policy scheme. However, all vessels must use compliant fuel whilst docked. The local government has been asked to license all tobacco retailers and to increase the tax by way of discouraging people to smoke. Their aim is to educate the public in the fact that smoking costs the Hong Kong economy in excess of $70 billion per annum.

The promotion and use of electric vehicles would greatly increase the quality of air in Hong Kong. Already, the electrification of public transport is being encouraged and charging stations available for public use are being installed in strategic places around the city.

There is an app downloadable to mobile phones (PRAISE-HK) which aims to inform the user as to the quality of air in their immediate vicinity. This information will allow then to make a choice as to whether to venture outdoors or not. This app also predicts the quality of air for the next 48 hours by using data modelling and weather forecasts. It only uses data that has been verified by government officials and not merely extracted from sensors.

What are the effects on health due to poor air quality in Hong Kong?

As a result of comprehensive studies in The Netherlands, it has been noted that mortality rates are notably higher near heavily used roads. The comparison was made between residential properties 50 metres and 100 metres away from the main road. This is of great significance to residents of Hong Kong as the majority live within close proximity of major highways. It has been stated that air pollution exacerbates asthma, raises the risks of cardio-respiratory deaths and greatly impairs the function of the lungs. These risks are increased by2 to 3 per cent for every rise of 10 µg/m³ of pollutants. These roadside levels of pollution in Hong Kong are blamed for the 90,000 admissions to hospitals and the premature deaths of almost 3,000 people.

Even healthy people experience health impacts due to breathing in polluted air. Simple activities such as outdoor activities and exercise are greatly affected. It is recommended that good quality masks are worn when outside, and if living in close proximity to a road, it may be worth considering the installation of an air purifier in the home. High levels of air pollution can cause such problems as aggravated cardiovascular and respiratory illnesses. The heart and lungs become increasingly stressed as they need to work so much harder to keep an adequate supply of oxygen to the blood. Cells in the respiratory system easily become permanently damaged through breathing in these micro fine pollutants.

Over a longer period of time of exposure, the lungs prematurely age and thus lose capacity and suffer from a decrease in function. Diseases such as emphysema, asthma, bronchitis and even lung cancer are capable of developing under such circumstances. This, in turn, can lead to a shorter life-span.

Those most susceptible to severe health problems are those with existing problems which could include congestive heart failure or coronary artery disease. Pregnant women, the elderly and outdoor workers are particularly vulnerable as are children under 14 years and those who engage in vigorous outdoor exercise.

It has been estimated that 8,500 people have already lost their lives in 2020 due to air pollution. It has also been responsible for an estimated 6.8 million home visits from the doctor and 64,000 hospital-days.

On days when the air quality is classed as moderate (51-100 US AQI) residents are encouraged to make use of indoor facilities, where possible. Even taking a walk through a large shopping mall as part of your exercise regime is encouraged.

Does Hong Kong’s poor air quality affect its economy?

As early as 2000 the recorded negative impact to the economy was in excess of HK$11.1 billion. It is estimated that 1,600 deaths can be avoided if the quality of the air in Hong Kong is improved. Having been made aware of these statistics it is said that pollution is driving away business and is detrimental to Hong Kong’s global competitiveness. Amongst other things, it is being called a business issue and a political issue.

One large American investment and wealth management company have downgraded Hong Kong property companies because they are concerned about the quality of the air. The head of the Hong Kong Stock Exchange has been warned by several large foreign investment companies that local air pollution is scaring investors away. Because of the long periods of poor air quality and the threat that poses to health, many investors are looking at alternatives, such as Singapore.

It has been proven that the air pollution is not only harmful to the health of its citizens but it is a major factor when foreign workers think about relocating to Hong Kong. The Danish Chamber of Commerce in Hong Kong stated that several of its potential new employees have declined an offer of work in the city because of the health risks associated with working in such a polluted environment. Several years ago, new recruits did not consider Hong Kong to be an unhealthy city, on the contrary, it was thought of as a modern metropolis with clean air. However, it has been recommended by a London-based HR company that in order to attract new employees from abroad, local companies should offer a further 10 per cent salary increase by way of a “hardship” allowance because of the poor air quality. It has also been noted that almost one fifth of the population has at some time considered leaving the city, citing poor air quality as the main reason.