Cambodia is also known as Kampuchea but officially it’s the Kingdom of Cambodia. It is located in the southern portion of the Indochina peninsula in Southeast Asia. It shares land borders with Vietnam, Thailand and Laos. It also has a coastline on the Gulf of Thailand. It is a sovereign state with a population of around 15.5 million in 2019.
At the beginning of 2021, Cambodia was experiencing a period of “Moderate" quality air, according to recommended levels by the World Health Organisation (WHO). The concentration of the PM2.5 pollutant was 20.9 µg/m³. With figures such as these, it is advisable to close doors and windows to prevent the ingress of dirty air into the home and those with a sensitive disposition should avoid outdoor activity until the air quality improves. If venturing outdoors is unavoidable, then a good quality mask should be worn.
According to figures from 2019, Phnom Penh, the capital city, experienced “Moderate” quality air for 11 months of the year with figures between 12.1 and 35.4 µg/m³. Only during August was the quality any better with a “Good” reading of 10.2 µg/m³. Looking back over the years, the air quality is getting slightly worse. In 2017 it was 20.8 µg/m³, 2018 - 20.1 µg/m³ and in 2019 it was 21.1 µg/m³.
The World Health Organisation sets the air quality guidelines for an average annual PM2.5 level of 10 µg/m³. Air pollution in Cambodia was higher at 26 µg/m³ in 2016. Cambodia's figures are better than the global average, however, at 51 µg/m³.
Air pollution comes from the burning of fuels such as kerosene, diesel and coal for transportation, domestic use and industrial and energy use. The burning of these fuels emits toxic fumes into the atmosphere that have a significant impact on air quality and human health.
Although Cambodia is not a highly industrialised country, it ranks 164th out of 180 countries in the Environmental Performance Index (EPI) for air quality in 2018.
The Ministry of Environment is the authority in charge of monitoring air quality and solving pollution problems in Cambodia. Established in 2000, the Sub-Decree on the Control of Air Pollution and Noise has set specific standards for air quality in the atmosphere. According to the law, the sources of air pollution are divided into mobile sources ( such as motor vehicles) and fixed sources ( such as factories).
The transport sector has a significant impact on air quality due to the growth of vehicles and fuel consumption. In 2016, more than 3.2 million vehicles were registered, including 2.7 million motorcycles, an increase of 14 per cent over the previous year and this figure is growing annually due to the richer middle-classes now being able to afford to buy a car due to higher levels of salaries.
In Cambodia, population growth and rapid economic growth are causing environmental pollution. Economic development activities have created significant environmental consequences, including air pollution, water pollution, noise pollution and solid waste. Industry is one of the most important sectors for the Cambodian economy. However, environmentalists have identified four major industrial activities that cause pollution: the garment industry, the brick kiln, the rice mill and the rubber processing industry.
The third ring road around Phnom Penh is almost 50 per cent complete. If all goes according to plan, it will be completed at the end of 2021. Currently, this is creating a lot of disturbance to the atmosphere due to the movement of soil and other loose materials.
Because of the climate and the cycle of the seasons, the quantity of dust in the air is significantly higher in the dry season. Most of Cambodia is agricultural land covered with sparse vegetation. As most of it is relatively flat, the winds pick up the dry dust from the land and carry it towards the cities. As the wind meets a building or other object it loses its ability to carry as much, consequently, it drops its contents, i.e. the dust. The dry season can last between 5 to 6 months.
There is currently a huge increase in construction in the bigger cities in Cambodia. Many older buildings need to be demolished to make way for the new build. This creates a huge amount of dust which is emitted into the atmosphere. Add to this the transportation of the rubble away from the site in open trucks. The trucks are required to cover their loads but often it is only with a loose-fitting tarpaulin. Consequently, the wind blows underneath it and carries the dust with it. This dust is deposited on the road which is then picked up by passing traffic as it is swirled up into the air. This dust is mainly made up of PM10 particles which are one of the worst type of pollutant as regards to human health.
In January 2020, the Royal Government instructed the relevant ministries, institutions and sub-national administrations to take measures to prevent and reduce public air pollution. This guideline is to better manage the location of air pollution sources to ensure the safety and well-being of the people as well as improve the beauty of the town.
The circular confirmed that enforcement of laws related to the management of air pollution sources is still limited and has not yet responded to the rapid growth of the national economy.
The letter said that the concentration of particles more than 2.5 micrometres, which is the pollution in the air, can pose a risk to public health and the environment.
The source added that the increase in particle concentration was due to emissions from industrial plants, diesel vehicles and other fuels such as forest fires, grassland fires and the burning of garbage and so on.
The head of government instructed his subordinates to monitor the construction site, the quality of fuel containing high sulphur, the release of air pollution from vehicles, the release of air pollution from production sites, the establishment of monitoring systems and forecast air pollution.
Environmental activists have argued that climate change and current pollution are partly due to the current massive deforestation. Forests contribute to reducing toxins in the atmosphere and releasing oxygen back into the atmosphere.
Hundreds of tuk-tuks and passenger cars continue to operate around the Angkor Wat site, posing a threat to air quality there. In 2014, it was reported that the air quality of Angkor Wat, a UNESCO World Heritage Site, had become a concern. Temples can be damaged by acid rain. A decade ago, air pollution in Siem Reap was worse than in Bangkok, a capital of more than 8 million people.
In 2014, it was reported that the transport network in Siem Reap would be better able to respond to environmental issues by launching 50 solar-powered passenger cars. These new cars cost $ 23,000 each. This new initiative was expected to address air pollution and acid rain. However, as of mid-2015, these cars have not been put to test use yet.
Air pollution can be concentrated in Phnom Penh and cannot be avoided as most of the vehicles and motorcycles are imported from the USA where they are deemed to be old and surplus to requirements. At present, there is a concern with the rapidly increasing number of vehicles and motorcycles in the city and the frequent congestion causing traffic jams. In this concentration, second-hand vehicles and motorcycles generally produce more pollutants than newer ones with the latest technology and catalytic converters. In addition, some illicit traffickers continue to import low quality gasoline which contains high levels of sulphur, lead and other hydrocarbons which are banned by the government and restricted by national standards.
There are so many vehicles in Phnom Penh which visibly pollute the environment. Many are old motorbikes and goods vehicles that visibly produce smoke as they travel through the city.
Modern motorbikes cut power to the engine once the cessation of forward movement is detected. This prevents the engine from idly running whilst waiting in a queue for the traffic lights to change. Thus preventing air pollution.
Towards the end of 2020, the first mobile air quality monitor was inaugurated, the first vehicle to monitor air quality anywhere in Cambodia. Ministry officials have confirmed that the mobile vehicle will be used to monitor air quality at the border to monitor cross-border air pollution.
The Royal Government of Cambodia has provided a mobile air quality monitoring vehicle and the first vehicle in Cambodia to the Ministry of Environment to monitor air quality and better manage the location of air pollution sources.
This portable air quality monitor has the ability to monitor 16 parameters and can detect positive inert particles only 1 micrometre, called PM1, which allows the Ministry to have sufficient capacity to monitor air quality everywhere in Cambodia, to collect air quality data anddisseminate to the public more accurately and timely.
It was reported that automatic air quality monitoring equipment had been installed in the capital. A number of them have been installed in Phnom Penh, whilst the rest are to be deployed throughout the provinces.
In Cambodia, as in other countries, economic development is certainly leading to an increase in the level of air pollution. The concentration of sulphur oxides, nitric oxides carbon monoxide and lead, and other substances are emitted from various sources such as vehicles, motorbikes, factories, generators, etc.
Cambodia is not a heavily industrialised country. Most of its factories produce garments and related products. The others are light industry such as food and beverages, textile, non-metallic mineral products, wood products, rubber manufacturing, etc. In general, most of the factories are located in the capital city of Phnom Penh. In 1999, about 170 factories were operating in and around Phnom Penh.
As most of the factories still use old technology and do not pay attention to environmental pollution as well as air pollution and never conduct an environmental impact assessment. Therefore, air pollution from the industrial sector is considered to be one of the major problems in Phnom Penh.
Electric supply in Cambodia is not yet adequate as the result of the long civil war from 1970 to 1993. In general, the electric power supply in Cambodia is inadequate for supporting services, so all service sectors use their own generator for supporting their businesses. They often site the generator outside near the road or next to their property. Therefore, the generators create many problems for the residents and people who are travelling on the roads by introducing exhaust gases into the air.
Biomass fuel, particularly firewood and charcoal are the main source of energy for cooking for 96.7 per cent of the households in 1999 in Cambodia; they are the cheapest and most easily accessible sources of energy used for cooking. Besides, households use charcoal, kerosene and fuel gas. Firewood burning products a large quantity of carbon dioxide and carbon monoxide in addition to other PM2.5 pollutants.
Toxic fumes that cause non-communicable diseases such as heart attack, lung cancer, stroke or chronic bronchitis killed 6.5 million people in 2015 worldwide.
Atmospheric fumes such as ozone (O3) or carbon dioxide (NO2) are rich in particles that are up to 10 times smaller than a human hair or it is about the size of a bacterium that cannot be seen with the naked eye. The particulate matter is found in toxic gases such as car exhaust fumes and from industrial plants that burn coal. Even the smoke from a fireplace or stove for heating in a country with very cold weather contains particulate matter that can damage the lungs and cause people to die of heart attacks.
Low-income people suffer the most from air pollution as they do not have the means to pay for cleaner fuels, so they resort to using cheaper ones which emit more pollutants.