Winter in sprawling Lahore spells horror for thousands of residents. Not because of cold but due to the phenomenon of smog. Let your gaze roam over the cityscape while standing on top of the Yadgar-e-Pakistan and one finds how the skyline of the minarets and domes looks dark and sad against the clouds of thick smog.
The fog is triggered by temperature inversion — the formation of a static layer of cooler air close to the ground as the nighttime temperature drops. Normally, air closer to the ground is warmer than the air above it, and therefore rises. Inversions are frequent on winter nights after the ground has cooled down so much that it begins to chill the air closest to it often causing mist to form as water vapor precipitates on dust particles. Normally the morning sun swiftly breaks through the mist and heats the ground, which warms the air above it, breaking the inversion.
The term smog was first used in 1905 to describe the conditions of fog that had soot or smoke in it. In fact the word smog had been coined from a combination of two words fog and smoke. Smog is a mixture of various gases with water vapors and dust. It is also referred to hazy air that causes difficult breathing conditions. A large part of the gases that form smog is produced when fuels are burnt.
Lahore is one of the cities with large number of registered vehicles, and many more coming and going every day from out of the city. Due to the concentration of heavy traffic, emissions of smoke and sculpture dioxide and nitrogen oxides are much greater than they are in adjoining rural areas. Some industrial concerns in and around Lahore also emit heavy amount of haze causing pollutants (mostly fine particles) directly into the atmosphere. Thick clouds of smog form when heat and sunlight react with the gases and fine particles in the air. Metrological Science experts say that air pollution can span broad geographic areas and be transported great distances, sometimes hundreds or thousands of miles. Consequently, smog occurs regionally throughout the Punjab sometimes.
Environmentalists attribute the heavy smog in Lahore, increasing in intensity as well as length of the smoggy period every year, to the constantly growing number of polluting vehicles that jam the city’s roads. Many of the vehicles plying on the city roads are old vintage and have engines that guzzle petrol and diesel, and spew out poisonous fumes. Even heavy vehicle commute most city roads freely. But “the main threat is obviously cars. It is a case of can we improve air quality fast enough as in the absence of suitable city transport system more and more cars come onto the roads of Lahore,” says Metrological expert Khan Ghulam Abbas.
“What Lahore is witnessing every winter since 1987 is the kind of killer smog that used to envelope cities like Los Angeles, London and Mexico City a few decades ago. While awareness about the dangers of pollution has resulted in improved emission standards in advanced countries, in Pakistan, we do not have clean environment concerns,” Khan adds.
The calm puffs of air from plains does not help in blowing away much of the pollutants for winters and a large part of it remain hung a few hundred feet above the ground in the city. So, most mornings and evenings – especially in December and January – mist or fog turned smog defines the climate of the metropolitan.
Smoke particles trapped in the fog give it a yellow black color and this smog often settles over city for days causing poor visibility — one of the most obvious indicators of pollution in the air. It often occurs as a result of smog that obscures the clarity, color, texture, and form of what people see. Result: The Lahore Airport remains close during long hours of smog disturbing schedule of national and international flights to and from Lahore. Motorway (M 2) has to be closed. Even railway schedule is affected.
The most harmful components of smog are ground-level ozone and fine airborne particles. Ground-level ozone forms when pollutants released from gasoline and diesel-powered vehicles and oil-based solvents react with heat and sunlight. It is harmful to humans, animals, and plants. Not only that, the prime ingredient in smog, can come into the houses and combine with the other household pollutants that emanate from flooring, citrus scents or solvents in air fresheners, floor cleaners, deodorizers and furniture polishes and can enters the lungs. Hint for the health minded is to keep the windows and ventilate while vacuuming. Not to spray chemicals. Even putting on nail polish inside the house adds a bit to the indoor pollution. Avoid air fresheners or scented candles and aggravates.
In winters, this vibrant and living city gets enveloped in smog from early morning and those suffering from lung ailments like asthma and other diseases are the worst sufferers. On many mornings, it fails to dissipate till even 10 AM. Doctors advise people to remain indoors, instead of going out on jogging or exercising out in the open. The last few days have seen hospitals reporting a large inflow of patients, especially children, suffering from lung ailments.
Relatively little has been done to control any type of pollution or to promote environmental protections until now in Pakistan. Today, smoke and sulphur dioxide pollution in cities is much higher than in the past. May be some government puts up a legislation to control pollution emissions. Or we keep getting used to the worsening situation. It is one of the very valid fields of scientific activities and political priorities elsewhere.
What are the conditions where you live?