Air pollution in Hong Kong has been a serious problem since the 2000s. Cases of asthma and bronchial infections have soared due to reduced air quality.
Background In the 1980s, the labour-intensive industries of Hong Kong faced the problem of increasing land rents and labour costs封, p.34 while the reform and opening up in mainland China provided a favourable condition for building factories there.封, p.35Keung Mainland China had labour and land and looser pollution control than Hong Kong.Ip, Lam and Wong, p.20 Therefore, Hong Kong industrialists took advantage of mainland China's pull factors by relocating their factories there.Ip, Lam and Wong, p.15
Most factories relocated to the Pearl River Delta.封, p.36 The first factories were relocated to mainland China in the late 1970s. The relocation trend reached its peak in the mid-1980s. By the 1990s, over 80% of the factories had been relocated to mainland China. The environment of Hong Kong has improved while that of mainland China is heavily polluted.Ip, Lam and Wong, p.30 Consequently, local governments of South China passed laws to restrict industrial pollution.Ip, Lam and Wong, p.31
The relocated factories needed support services including shipping, insurance, and above all, finance. As more people working in the tertiary sector, Hong Kong's economy grew increasingly reliant on service industries.何, p.88
Major emission sources
The Environmental Protection Department (EPD) published the Hong Kong Air Pollutant Emission Inventory on their website every year since 2000. , there are "seven source categories for six major air pollutants, namely: sulphur dioxide (), nitrogen oxides (NOx), respirable suspended particulates (RSP or PM), fine suspended particulates (FSP or PM), volatile organic compounds (VOC) and carbon monoxide (CO)".
"The emission sources include non-combustion sources, public electricity generation, road transport, navigation, civil aviation, other combustion sources, and hill fires" according to the inventory. Hill fires are considered random in nature by the EPD and are not included in the chart below. In 2022, other combustion sources (e.g., non-road mobile machineries operating in construction sites and container terminals) and non-combustion sources (e.g., for VOC, paints and associated solvents, consumer products and printing; for respirable suspended particulate, i.e., PM10, and fine suspended particulate, i.e., PM2.5, paved road dust, cooking fumes, construction dust and quarry production) are major emission sources for PM2.5, PM10 and VOC (as compared with combustion sources such as public electricity generation, road transport, navigation and civil aviation).
2022 Emission Inventory
Other major air pollutants in Hong Kong include ozone and lead. Ozone can be called a secondary pollutant. Volatile organic compounds (VOCs) react with nitrogen oxides (NOx) to form ozone under sunlight, "which in turn helps the formation of fine particulates. The accumulation of ozone, fine particulates and other gaseous pollutants results in smog that reduces visibility." The production and concentration of ozone depends on the presence of primary pollutants and UV light. "In the presence of volatile organic compounds, high concentrations of ozone are formed. This type of pollution … is termed 'photochemical smog'."
Effects
Declining regional air quality means visibility has also decreased dramatically. In 2004, low visibility occurred 18 per cent of the time, the highest on record, according to the Hong Kong Observatory.
Health implications The mortality rate from vehicular pollution can be twice as high near heavily travelled roads, based on a study conducted in the Netherlands at residences 50 metres from a main road and 100 metres from a freeway. Since millions of people in Hong Kong live and work in close proximity to busy roads, this presents a major health risk to city residents. The Hong Kong Medical Association estimates that air pollution can exacerbate asthma, impair lung function and raise the risk of cardio-respiratory death by 2 to 3 per cent for every increase of 10 micrograms per cubic metre of pollutants. Studies by local public health experts have found that these roadside pollution levels are responsible for 90,000 hospital admissions and 2,800 premature deaths every year. In 2009 the Australian government highlighted that air pollution in Hong Kong could exacerbate some medical conditions.
Former Chief Executive Donald Tsang declared that the high life-expectancy of Hong Kong demonstrates that concerns over air quality were not justified.
Professor Anthony Hedley, chair of community medicine at Hong Kong University, said: "Tsang is badly advised on current public health issues." Hedley added that air pollution levels in Hong Kong were extremely high, and could affect the lungs, blood vessels and heart. James Tien, former Chairman of the Liberal Party of Hong Kong, retorted, "Can [Tsang] really be confident that, if pollution continues to worsen, will he be able to promise the same life expectancy for our children and for our grandchildren?"
Economic impact Even as early as 2000, the total negative impact to the Hong Kong Economy, including cardiorespiratory disease was in excess of HK$11.1 billion. About 1,600 deaths a year might be avoided if air quality improves.
Made aware of fresh statistical and anecdotal evidence that pollution is driving away business and hurting Hong Kong's global competitiveness, James Tien called air pollution "a health issue, a lifestyle issue, a tourism issue, a business issue, and increasingly a political issue".Jonathan Cheng, Lot of hot air on pollution, claims Tien , The Standard, 4 December 2006
In 2006, Merrill Lynch downgraded several Hong Kong property companies because of air quality concerns, and there have been warnings from the head of the Stock Exchange that pollution was scaring investors away. It said that the air quality in Hong Kong is now regularly so poor that its "long-term competitiveness is in some doubt".Our future up in the air , William Pesek, The Standard, 8 December 2006
Pollution is dramatically harming not only the health of citizens of Hong Kong but also its economy, particularly relating to the ability to attract skilled foreign labour.Hong Kong Wheezes as China's Industrial Economy Belches Smog, Bloomberg, 13 October 2005
The chairman of the Danish Chamber of Commerce in Hong Kong said there are people declining offers to work in the Hong Kong offices due to pollution: "It's going to cost us in the future if we don't clean up here."
"Five years ago, air quality wasn't a concern when people considered whether to relocate to Hong Kong", the Chief Executive of Jardine Engineering Corp. said in 2006. "In the past, one of the advantages was clean air. We can no longer say that." A London-based human resources consultant said.
Causes
Construction dust and quarry production Construction dust and quarry production are major causes of air pollution in Hong Kong. As of March 2024, there are 1668 construction sites in Hong Kong, around half of them are from private sector and the remaining are from public sector.
Concrete plant Concrete batching plants contribute to air pollution in Hong Kong.
Materials or wastes not properly covered
Dusty materials that are not cleaned up or properly covered (e.g. in construction sites and dump trucks) are causes of air pollution in Hong Kong, "Everyday, hundreds of dump trucks carry all kinds of dusty material from construction sites to public filling barging points. Improper covering of dusty material would result in substantial fugitive dust emissions during road transportation. Consequently, the air quality of Hong Kong, in particular, the total suspended particulate, would be greatly affected."
Renovation and refurbishment
Renovation and refurbishment can emit particulates and other pollutants. A large amount of waste can be generated and result in air pollution. Common pollutants include volatile organic compounds (VOCs) (from solvent-based paints, solvents and adhesives) and dust from cutting, grinding, polishing and sanding materials. There were reports that lead paint was used for renovation in Hong Kong and caused significant ... effects on human.
There are more than two hundred thousand home improvement projects every year in Hong Kong, affecting more than a million residents (population of HK is around 7.5 million in 2023).
Unregulated Power Tool Usage The amount of power tool usage in dense urban areas generates a significant amount of air pollution. Angle grinders, wall chasers and grit blasters produce particulates that are finer than PM2.5 pollutants.
Some power tools are equipped with dust collection systems (i.e., HEPA vacuum cleaner) or integrated water delivery system which extract the dust after emission.
The usage of power tools can cause adverse effects on people. Power tools can produce large amounts of particulates including ultrafine particles. Use of hand tools can also produce nanoparticle, although the total particle number concentration (PNC) results may be lower than that of using power tools. Plastics are extensively used in the construction and renovation industry. Airborne microplastic dust (a type of particulates) is produced during renovation, building, bridge and road reconstruction projects and the use of power tools. Microplastics is also generated by deterioration of building materials
Particulates are the most harmful form (other than ultra-fines) of air pollution There is no safe level of particulates. Many tasks create dust. High dust levels are created by:
Equipment – using high energy tools, such as cut-off saws, grinders, wall chasers and grit blasters produce a lot of dust in a very short time Work method – dry sweeping can make a lot of dust when compared to vacuuming or wet brushing Work area – the more enclosed a space, the more the dust will build up Time – the longer you work the more dust there will be Examples of high dust level tasks include: using power tools to cut, grind, drill or prepare a surface sanding taped plaster board joints dry sweeping
Some power tools are equipped with dust collection system (e.g. HEPA vacuum cleaner) or integrated water delivery system which extract the dust after emission.
The use of certain types of power tool such as angle grinder can produce much more harmful sparks and fumes (and particulates) when compared with using reciprocating saw or band saw.
Hill fire Hill fire (or wildfire) is a main source of air pollution. According to the Agriculture, Fisheries and Conservation Department (AFCD), major causes of hill fires include joss paper and sticks not extinguished after grace sweepers' worship activities, outdoor barbecuing or cooking, and burning of vegetation and rubbish. "The countryside is therefore prone to high fire risk. Although fires occur in natural environments, almost all are caused by human negligence." To prevent hill fire, the AFCD suggested that weeds around the grave should be cleared by hand-tools, joss paper and sticks should only be burnt in containers, and "never burn rubbish, weeds or grasses".
Wildfires release large amounts of carbon dioxide, black and brown carbon particles, and ozone precursors such as volatile organic compounds and nitrogen oxides (NOx) into the atmosphere. ... Wildfires also emit substantial amounts of semi-volatile organic species that can partition from the gas phase to form secondary organic aerosol (SOA) over hours to days after emission. In addition, the formation of the other pollutants as the air is transported can lead to harmful exposures for populations in regions far away from the wildfires. While direct emissions of harmful pollutants can affect first responders and residents, wildfire smoke can also be transported over long distances and impact air quality across local, regional, and global scales.