Air pollution, got a lot of attention in Sri Lanka after the country’s cricketers had to face its effects during the 3rd test match against the Indian team at New Delhi recently. Cricketers and spectators inhaled the grey smoggy air and suffered the consequences.
Air is the most vital element of life. Though life can sustain without water and food for a few days, having no air brings immediate death.
The air we breathe contains the elements necessary for our existence. It is a cocktail of different gases and a variety of invisible minute particles known as particulates. Among them is Oxygen (O2) which fuels life and Carbon dioxide (CO2) the base of all sustenance. O2 fuels human and animal cells alike and transforms it into CO2 the waste product of human and animal respiration.
However, the design of nature has assured the replenishment of the lost O2 in the atmosphere, CO2 being the main ingredient facilitating food production in the trees and plants. While the green leaves produce numerous hydrocarbons (CH) for the survival of both animals and humans during day light hours utilizing atmospheric CO2 in a process called photosynthesis, they emit O2 as their waste product. This cycle has been going on for millennia balancing the earth’s radiation and keeping it a habitable planet.
However, the air that we breathe is being polluted and the consequences make it a global concern.
What is air pollution?
Environmentalists define air pollution as “the presence of toxic chemicals or compounds (including those of biological origin) in the air, at levels which lower the quality of the air or cause detrimental changes to the quality of life.”
According to the World Health Organisation (WHO), it is “contamination of the indoor or outdoor environment by any chemical, physical or biological agent that modifies the natural characteristics of the atmosphere.”
Simply stated, anything that changes the natural composition of the atmosphere is a pollutant. The air we breathe consists mainly of Nitrogen (N) an inactive gas – 78 percent and Oxygen (O2) a highly combustible and active gas – 21 percent. All the other gases including Carbon dioxide (0.036 percent), water vapor and visible and invisible particles/particulates fill up the one percent left over. This balance, especially of the cocktail of gases consisting one percent of the ambient air is essential for the existence of life on earth. The increase of any of these gases could make itself a pollutant as it would cause changes that could have a profound and damaging effect. So are the particulates.
Since the time man started burning fossil fuel, the natural composition of the atmosphere has been changing. Minutely in the beginning. The Industrial Revolution brought in the anthropogenic (man made) gases and other pollutants. The infrastructure and settlement requirements of the booming world population entailed increased deforestation decreasing the natural production of O2 while increasing the demand. Throughout the years pollution has been rising and now at a rate that brings in scientists , activists and governments together in a bid to find mitigatory and adaptive measures. Air pollution is a serious environmental problem confronting the world today.
How is air pollution caused?
Air pollutants could be chemical, physical or biological. If you had ever followed the smell of your favourite food to the kitchen, or changed the ambience of a room with an air freshener you have experienced a chemical change in the air. If you happened to light and smell a fire or walk, stand or ride beside a tractor unloading sand or bricks on the wayside you have experienced a physical change in the air. If you had had a sneezing fit walking beside a blooming flower-bed or caught influenza being in the same room with someone, you had experienced the effects of a biological change in the air. These are a few of the most common incidences which could ‘change’ the natural composition of air and pollute the surroundings. However, when such composition changes persist, it becomes a predicament. Moreover, it also acts as a catalyst to cause a chain reaction of a host of other problems.
Air pollution is the cause of the greenhouse effect and resultant global warming, climatic changes, ozone depletion, acid rains, adverse environmental health conditions and many more.
The exchange between incoming solar radiation and outgoing radiation emitted by the atmosphere, is often referred to as the greenhouse effect. It helps to keep the earth warm and habitable in the same way that a greenhouse functions. The main greenhouse gases in the earth’s atmosphere are Carbon dioxide (CO2) and Methane (CH4). Nitrous oxide and fluorinated gases such as, chlorofluorocarbons, hydrochlorofluorocarbons, hydrofluorocarbons, perfluorocarbons, sulfur hexafluoride, nitrogen trifluoride and the like play a major role in warming the earth, as some of these could also cause the depletion of the ozone (O3) layer which absorbs the sun’s ultraviolet (UV) radiation protecting the earth from its harmful rays.
Most of these gases are released anthropogenically, mainly by fossil fuel burning and other industrial processes. As the atmosphere is a continuum around the globe unlike the geosphere or the hydrosphere which separates different regions of the world, whatever pollutants released into the air in the smallest place could in time adversely affect the whole world.
Air Pollution in Sri Lanka
According to Breathe Life, a website which features data collected by WHO’s Global Platform on Air Quality and Health, measurements for the annual average exposure to particulate matter- PM 2.5, (the invisible particles measuring only 2.5 micrometers that can penetrate the body and are most closely linked with premature death and climate change) in Colombo is 3.6 times higher (36micro g/m3) than the recommended levels of exposure by the WHO (10micro g/m3). Throughout Sri Lanka it is 27mg/m3. The site claims that on an average in Sri Lanka, 7,792 people die from air pollution-related diseases each year, citing the 2012 census and statistics. While ischemic heart disease is presented as the top killer among air-pollution related diseases, the website claims that 33 children die of air-pollution related diseases each year.
Air pollution is a “burning environmental problem” in the country says H.D.S. Premasiri, Senior Scientist, National Building Research Organization (NBRO), who has been conducting research on air pollution since 1989. Urbanisation, industrialization, vehicular traffic, high population and domestic activities have been contributing to create and aggravate the air pollution problem in Sri Lanka.
Vehicular traffic is a major contributor to air pollution in the cities. The latest figures from a study conducted in 9 major cities, NBRO research revealed, in Colombo and Kandy, both Nitrogen dioxide (NO2 and Sulfur dioxide (SO2), two GHG contributing to the greenhouse effect and acid rains are above the levels of concentration recommended by the WHO.
SO2 and NO2 levels
Another study had found that the increase of SO2 and N2O levels in ambient air is correlated to the increase in vehicular traffic. As a mitigatory measure, Sri Lanka introduced cleaner vehicles such as, hybrid and electric vehicles which had reduced the NO2 and SO2 concentrations in the ambient air quality. Further, cleaner fuel had been introduced reducing the Sulfur levels to 500ppm (parts per million) in normal diesel and 10ppm in super diesel. Regulations had been introduced to limit the vehicular emissions.
However, since 2012 Sri Lanka’s operational vehicle fleet has doubled says Prof. D. S. Jayaweera, Consultant, Strategic Enterprise Management Agency. About 35 to 40 percent of this increase had happened during the last 2 years. The daily trips of vehicles in and out of the Colombo Metropolitan Region’s (CMR) core area had increased to 1.1 million. In a bid to reduce the operational fleet and thereby traffic congestion and air pollution, the CMR transport management project plans to introduce improved rail and bus transportation facilities from high populated zones around Colombo to key commercial and administrative hubs.