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Sri Lanka is officially known as the Democratic Socialist Republic of Sri Lanka and was formerly known as Ceylon when it was under British rule. It is an island country in the Indian Ocean of the south-eastern coast of India. Colombo is its largest city and commercial centre. In 2019 the population was estimated as being almost 22 million people.
According to the reputable Swiss company, IQAir.com Sri Lanka recorded a “Moderate” figure for air cleanliness in 2019 with a US AQI figure of 78. The average annual concentration of the pollutant PM2.5 was 25.2 µg/m³. This is according to suggestions from the World Health Organisation (WHO). For the month of August, the quality was recorded as being “Good” with a number between 10 and 12 µg/m³. For January, February and March. The figure was “Unhealthy for sensitive groups” with figures between 35.5 and 55.4 µg/m³. For the remaining months, the figures were “Moderate” with measurements between 12.1 and 35.4 µg/m³.
The average figure for 2019 of 25.2 µg/m³ was an improvement on the previous year of 32 µg/m³. On a global scale, Sri Lanka was ranked as the 25th dirtiest country out of a total of 98.
According to the recently released data, air pollution has increased in most parts of the country except in the south, including Colombo, Kandy, Puttalam, Vavuniya and Jaffna. As the impact of COVID 19 increased in Sri Lanka, various restrictions were imposed there. As a result, environmentalists say the current rise in air pollution is a cause for concern, although the rate of air pollution should have been reduced as traffic has decreased. The report said that air pollution within the country may have increased due to the prevailing windy weather in the areas surrounding Sri Lanka. It is also said that due to high levels of air pollution in India, there is a possibility of air pollution in the border areas of Sri Lanka.
Air quality in Sri Lanka is affected by vehicle emissions, organic waste burning, by-products from the agricultural industry, and petroleum refining. Available data indicates that Colombo often experiences high levels of air pollution.
As with many Asian countries, vehicle emissions are problematic because most of the vehicles are old and do not pass current regulations on emission control. Even though there is a public transport system, most people like the independence of using their own vehicle for the daily commute. There is also a 1500 kilometre rail system and three deep-water ports on the island. A fourth one has been built at Hambantota.
Air pollution from both indoor and outdoor sources is a major environmental health problem which affects millions of people worldwide, in both developed and developing countries. Although there are many chemicals and other substances suspended in the air, it is the microscopic particulate matter known as PM2.5 which is the most dangerous. Other substances used as a point of reference are: ground-level ozone (O3), carbon monoxide (CO), sulphur oxides (SOx), nitrogen oxides (NOx) and lead (Pb). These are the ambient pollutants which are found outside. Indoor pollutants can be slightly different and include: environmental tobacco smoke (ETS), formaldehyde and polycyclic organic matter.
According to figures released from 2019, the cleanest city in Sri Lanka was Kandy which is located in the central highlands. It lies amongst the hills of the Kandy plateau which are mainly covered by tea bushes as Kandy is the main tea growing area in Sri Lanka. The average 2019 reading was 69 US AQI as opposed to Colombo which had the worst figures of 78 US AQI, so you can see, there is not a big difference between the two cities.
There is a public transport system here which relies mainly on buses. The main terminus is located next to the railway, thus making it very convenient for onward journeys. The Kandy Multimodal Transport Terminal handles around 2,000 bus departures per day and a further 3,000 as they pass through en route to other places. It is estimated that accounts for almost 320,000 on a daily basis.
Some key steps have been taken by the government. The National Policy on Urban Air Quality Management was inaugurated in 2000. Leaded gasoline was prohibited in June 2002, the introduction of low-sulphur diesel was introduced in January 2003 and 2008 saw the complete ban on the importation of two-stroke Three-Wheelers. A vehicle emission testing centre was also established in 2008.
The permissible ambient air quality levels for selected air pollutants were for the first time enacted under the National Environmental (Ambient Air Quality) Regulations of 1994. With the publication of World Health Organisations (WHO) air quality guidelines in 2005, air quality standards for Sri Lanka, including standards for PM10 and PM2.5, were amended and brought into force in August 2008.
Despite many requests, Colombo still only has 1 ground-level monitoring station, located at the fort. Based on data from this station, the average annual ambient PM10 levels in Colombo have remained relatively stable over the years ranging from 72 to 82 µg/m³. The WHO recommends that this figure should be less than 20 µg/m³. From 2003 to 2005 it was decided to compare levels of pollution in Sri Lanka to levels found elsewhere in other Asian countries in a similar situation to Colombo. The results showed that Colombo is unhealthier than cities such as Hong Kong, Singapore, Bangkok, Taipei and Tokyo.
Very high levels of pollutants were found during the northeast monsoon period which can last from November to January. Carbon monoxide and ozone were found to be relatively low when compared to other pollutants. Many criticisms have been voiced about the accuracy of the data because of the location of the fort. It is only 800 metres from the ocean and as such “loses” some of the airborne particles due to the prevailing winds. It is felt that a more accurate figure could be achieved by establishing a few more monitoring stations or even moving the current one to a more suitable position. Newly established factories have been built together with power plants but these are several kilometres away and therefore do not get measured.
Indoor exposure is a result of composite interactions between the structure of the building systems, indoor source strength, removal and deposition rate within the structure, indoor mixing and chemical reactions between the chemicals, furnishings, the outdoor environment, and the practices and the behaviours of the inhabitants. If windows and doors are closed, they will remain trapped inside with no way of escaping. Sri Lanka is classed as a tropical country and, as such, would have been thought to have a good ventilation system. However, looking at what figures are available, it is seen that indoor air quality can often be worse than the outdoor air.
Cooking fuel is the main source of indoor pollution because the fuel is cheap and mostly is readily available. Tobacco smoke and smoke from other sources all come together to form a toxic environment. According to research figures, firewood is used by up to 79 per cent of households and it is thought unlikely to change in the foreseeable future. Most traditional stoves use firewood as their main source of energy which does not combust completely resulting in very high levels of pollutants issuing into the atmosphere. Measurements are taken at random found figures exceeding 1200 µg/m³ in many households. Possibly the worst group of people affected by this is women and children who tend to “stick” with mum whilst she is cooking. A cross-sectional study conducted to measure sulphur dioxide (SO2) and nitrogen dioxide (NO2) levels indoors and outdoors of 30 households at five different locations in Colombo reported that indoor pollutant levels in these low income houses were higher than those outdoors in all cases.
In this study, parents kept a daily activity diary for their 5 to 8 year-old children which showed that these children spent an average of 41 hours (out of 48 hours) inside their homes during weekends.
The regular use of mosquito coils which are used by over 10 per cent of all households adds to the toxic mixture of indoor air.
Even though it is banned in public places, smoking still takes place in private homes. Although there has been a reduction in the amount of adults who regularly smoke, it is estimated that there are still over a third of adults who smoke at home.
Air pollution in Colombo was at a moderate level of 26 towards the end of 2020. This moderate level ranges from 12.1 to 35.4 µg/m³. This is predicted to be an almost acceptable level. However, it can cause some health problems for those who are internally sensitive to air pollution. At the same time, active children and the elderly, as well as those with respiratory illnesses, especially those with asthma, need to take extra precautions. Wearing a good quality face mask is beneficial and avoiding heavily polluted areas.
The current moderate level of air pollution is expected to continue until the end of the year.
The most dangerous type of pollutant found in the air is PM2.5. So-called because of its microscopic size of less than 2.5 microns. Particles of this size can easily bypass the body’s natural defence mechanism and easily enter the lungs where they have the ability to travel to the base of the bronchial tubes where they eventually lodge in the alveoli. The average adult human has approximately 480 million of these tiny sacs. When the body breathes in, they expand to take in the oxygen and when shrink to expel the carbon dioxide. These tiny structures when looked at as one, make up a considerably large surface area. It is estimated that they would occupy a space of 100 square metres. This large surface area is necessary to process the huge volumes of air taken in by the body every minute. The average pair of adult lungs take in between 5 to 8 litres of air per minute.
These tiny sacs are very efficient but can soon become damaged by foreign bodies such as PM2.5. They also deteriorate due to cigarette smoking, the natural ageing process and air pollution.
Air pollution has a major impact on the process of plant evolution by preventing photosynthesis through the dusty deposits on their leaves, in many cases, with serious consequences for the purification of the air we breathe. It also contributes to the formation of acid rain, atmospheric precipitations in the form of rain, frost, snow or fog, which are released during the combustion of fossil fuels and transformed by contact with water and other chemicals in the atmosphere. Air pollution is also a major contributor to global warming and climate change. The huge amount of carbon dioxide in the air is one of the main causes of greenhouse gases.
The answer to its reduction is the move away from the reliance on fossil fuel and change over to more eco-friendly ways of producing energy. Think of solar power, wind power and hydropower. Energy conservation and efficiency also play a key role.
Changing to electric or hydrogen-powered vehicles helps, as does sharing cars with others. Because of modern GPS technology, it is easier than ever to make contact with others who are travelling to the place where you need to be.
From the planning stage to the demolition, green buildings can help the air quality in our cities in many ways. There is even a type of paint available now which reduces pollution in the air surrounding it. There is also a type of concrete that does a similar thing.