It is noon on a Monday, November 22 to be exact. As the motorcycles, trishaws, cars, buses pause or move whenever the red light changes at the busy Eye Hospital Junction, their drivers hardly spare a glance at a small black box kept atop a stool with a tube pointing in their direction.
A similar activity has taken place at three other locations across the country, in Maharagama, Kurunegala and Kandy.
A vital check is being carried out by these black boxes - the quality of the air that men, women and children breathe is being tested.
This has been done in October, that day it was done in Nove-mber, and it will be carried out once more in December and January to ascertain what Sri Lankans take into their lungs every time they inhale air to keep themselves alive.
The ambient air quality is being tested under a pilot project launched by Clean Co - Drive Green and Laugfs Eco Shri, the Sunday Times learns. These two companies which carry out emission tests on vehicles have undertaken the pilot project to make people aware of the importance of air quality.
Samples of air from the four locations are taken for one hour not by the two companies but by an independent surveying company SGS Lanka (Pvt) Ltd., well-equipped with both the necessary tools and the technology.
What happens when we inhale
The vehicle emissions which result in fuel combustion can not only cause chronic asthma but also chronic obstructive pulmonary disease, said Consultant Chest Physician, Dr. Bandu Gunasena who is attached to the Welisara Hospital when contacted by the Sunday Times.
Urban children are more prone to asthma than rural children and foreign studies have indicated that people living close to major highways have a higher chance of developing such diseases, he said.
If the gases generated by fuel combustion are inhaled over a long period of time, they can destroy the airways of the respiratory system and lead to chronic bronchitis, pointed out Dr. Gunasena, as what happens in smokers.
Explaining why the two companies thought it necessary to carry out the pilot project, a spokesperson for Clean Co - Drive Green said that many people don't understand the importance of air quality. "We hope to make people aware of the unseen quality of air to encourage them to keep improving it because it is not only beneficial to each and every individual but also to the country," he said.
Almost all vehicles use internal combustion engines for power generation, where fuel is burnt in an enclosed cylinder and the resulting explosion is used to drive a piston in a certain manner. However, as a result of imperfect fuel combustion, some part of the fuel remains unburnt or burnt incompletely.
Such imperfect combustion, as well as poor fuel quality, results in major pollutants being emitted through vehicle exhausts. The pollutants include particulate matter, oxides of nitrogen (NOx), carbon monoxide (CO), sulphur dioxide (SO2) and unburnt hydrocarbons (HC), the spokesman said.
With a boom in the number of vehicles on the roads, many countries including Sri Lanka have introduced strict measures to ensure that emissions cause a minimum of pollution. In some of these countries, testing vehicles for emissions takes place as many as four times a year, it is understood, as it is crucial to maintain the vehicle in that condition. If the vehicle is not maintained, even around six months after an emission test, it may spout out pollutants.
Air consists of around 78% nitrogen and 21% oxygen. A naturally aspirated engine takes in both nitrogen and oxygen in these proportions. High temperatures developed in an internal combustion engine during its combustion cycle favour a chemical reaction between nitrogen and oxygen resulting in the formation of nitrogen oxides. These nitrogen oxides also combine with unburnt hydrocarbons in the air resulting in the formation of smog, he said.
Carbon monoxide and carbon dioxide are collectively known as green house gases as their accumulation in the atmosphere is considered a major cause of climatic changes such as global warming and the green house effect. While carbon dioxide is not considered to be very dangerous, carbon monoxide, the colourless, odourless, poisonous gas is called the silent killer. Usually it is created during incomplete combustion of fuel such as during a cold start-up, says the spokesman, adding, “Particulate matter refers to fine particulates of dust, carbon or other liquid or gaseous materials suspended in air. Categorized on the basis of size, particulate matter.”
Meanwhile, a majority of diesel and gasoline fuels contain sulphur and burning of these fuels in the engine creates sulphur dioxide. Sulphur dioxide and nitrogen oxide combine with airborne water vapour causing acid rain.
How do vehicles fare?
A vehicle, except a brand new one, cannot run on the road without a revenue licence and to obtain that the emission testing certificate is mandatory each year, stressed the Commissioner-General of Motor Traffic, B.D.L. Dharmapriya, explaining that brand new vehicles are exempted for three years.
The number of vehicles registered up to November 2010 is 321,984 and includes 184,709 motorcycles; 78,365 trishaws; 18,489 motor cars; 11,585 hand tractors; 9,969 lorries; 7,717 single cabs; 3,786 tractors; 2,212 dual-purpose vehicles; 2,185 motor coaches; 319 special purpose vehicles; 254 lorry trailers; 252 lorry tractors; 51 ambulances; 12 hearses; 11 other types (fork-lifts) and 2068 others.
Asked if the department conducts checks on the condition of vehicles throughout the year, Mr. Dharmapriya said spot checks or random checks are not being carried out at present. To do this, the department will have to be strengthened both in terms of manpower and equipment.
The Sunday Times understands that there are about 200 centres of both Laugfs and Green Drive around the country for vehicle emission testing which was first begun in the Western Province in November 2008, expanded to cover the Southern, Central and North Central Provinces by June-July 2009 and Sabaragamuwa, Uva and Wayamba by December 2009.
Vehicle emission testing has not been launched in the north-east yet.
If a vehicle fails the emission test, the answer is simple, it is understood. The vehicle needs to be taken to any garage where the problem will be sorted out.
Meanwhile, a survey carried out by the Drive Green Project on the level of petrol consumption of trishaws before and after emissions were brought to the required low levels also showed that with emissions down, 25% of the fuel consumption could also be reduced.