Smog is a kind of air pollution, originally named for the mixture of smoke and fog in the air. Classic smog results from copious amounts of coal burning in an area and is caused by a mixture of smoke and sulfur dioxide. In the 1950s a new type of smog, known as Photochemical Smog, was first described. Smog is a problem in many cities and continues to harm human health. Ground-level ozone, sulfur dioxide, nitrogen dioxide carbon monoxide is especially harmful to senior citizens, children, and people with heart and lung conditions such as emphysema, bronchitis, and asthma. It can inflame breathing passages, decreasing the lungs' working capacity, and causing shortness of breath, pain when inhaling deeply, wheezing, and coughing. It can cause eye and nose irritation and it dries out the protective membranes of the nose and throat and interferes with the body's ability to fight infection, increasing susceptibility to illness. Hospital admissions and respiratory deaths often increase during periods when ozone levels are high. The U.S. EPA has developed an Air Quality index to help explain air pollution levels to the public. 8-hour average ozone concentrations of 85 to 104 ppb are described as "Unhealthy for Sensitive Groups", 105 ppb to 124 ppb as "unhealthy" and 125 ppb to 404 ppb as "very unhealthy." Smog can form in almost any climate where industries or cities release copious amounts of air pollution. However, it is worse during periods of warmer, sunnier weather when the upper air is warm enough to inhibit vertical circulation. It is especially prevalent in geologic basins encircled by hills or mountains. It often stays for an extended period over densely populated cities or urban areas, such as London, New York, Los Angeles, Mexico City, Houston, Toronto, Athens, Beijing, Hong Kong, the Randstad or Ruhr Area and can build up to dangerous levels.
In the Great Smog of 1952, the city of London was brought to a standstill by a dense blanket of toxic smog that reduced visibility to a few feet. For five cold December days, a heavy fog combined with sulfurous fumes from coal fires, vehicle exhaust, and power plants, blocking out the sun and creating a public health disaster. The "Big Smoke" was the worst air pollution crisis in European history, killing an estimated 8,000 to 12,000 people. Following a government investigation, however, Parliament passed the Clean Air Act of 1956, which restricted the burning of coal in urban areas and authorized local councils to set up smoke-free zones. Homeowners received grants to convert from coal to alternative heating systems. The transition away from coal as the city’s primary heating source toward gas, oil, and electricity took years, and during that time deadly fogs periodically occurred, such as one that killed about 750 people in 1962. None of them, however, approached the scale of the 1952 Great Smog.
For nearly two weeks, Lahore, Pakistan’s second-largest city, has been under a very thick smog. But when air-quality of the city was checked by the monitoring facility installed to track the city’s appalling pollution. It said that levels of the dangerous particulates known as PM2.5, small enough to penetrate deep into the lungs and enter the bloodstream, had reached 1,077 micrograms per cubic meter — more than 30 times what Pakistan’s government considers the safe limit. the Punjab government admitted it had “scant” air quality data, saying only that the official safety limit for PM2.5 particles, 35 micrograms per cubic meter, was “exceeded frequently. For years, Pakistani environmentalists have referred to November, when crop burning, higher emissions, and wintry weather combine to blanket Lahore and the rest of Punjab Province with acrid smog, as a “fifth season. A new policy on the lines of London is required to tackle the issue.
Monitoring and Evaluation of Smog Reasons
In London Generation of 1000 tons of particulate matter/day (including 140 tons of HCL, 14 tons of fluorine compounds, 370 tons of Sulfur dioxide), Rapid increase in population, Deforestation and de-vegetation, Industrialization and coal-based electricity generation plants, Burning of fossil fuels were the main reason with become the reason of accident in 1952. Atmospheric scientists at Texas A&M University investigating the haze of polluted air in Beijing realized their research led to a possible cause for the London event in 1952. "By examining conditions in China and experimenting in a lab, the scientists suggest that a combination of weather patterns and chemistry could have caused London fog to turn into a haze of concentrated sulfuric acid. Even though research findings point in this direction, the two events are not identical. In China, the combination of nitrogen dioxide and sulfur dioxide, both produced by burning coal, with a humid atmosphere, created sulfates while building up acidic conditions that, left unchanged, would have stalled the reaction. However, ammonia from agricultural activity neutralized the acid allowing sulfate production to continue. It is theorized that in 1952 in London, the nitrogen dioxide and sulfur dioxide combined with fog rather than humidity; larger droplets of water diluted the acid products, allowing more sulfate production as sulfuric acid. Sunrise burned off the fog, leaving concentrated acid droplets which killed citizens.
However, in the Lahore incident, the main reasons include Increase in the vegetation of rice crop in Haryana-India as Indian farmers burned 350 million tons of rice crop residues this year. Industrialization inside the city, and nearby cities of India, Installations of 12 fossil-fuel electricity generation plants around the city, Automobiles (around 2 million private cars are present in Lahore city), the Lower standard of gasoline fuels, Wire recovery industry by burning the tires, High rate of rising in population. All these reasons were working to worsen the situation which ultimately resulted in that major incident. Also, one of the reasons was deforestation which was revealed by a group of Belgian researchers. In the last ten years in Lahore, the total tree cover went down by 75%. The study under the project did the change analysis at irregular intervals from 2007 to 2015, the results were no less than a shock, in 2007 tree cover in Lahore was 12,359 hectares which reached to 7,965 hectares in 2012 and further decreased to 3,520 hectares in 2015.
Facts and figures
The Clean Air Act 1956 was an Act of the Parliament of the United Kingdom passed in response to London's Great Smog of 1952. It was in effect until 1964 and sponsored by the Ministry of Housing and Local Government in England and the Department of Health for Scotland. The main policies of the act are as follows
Ban on coal fires in the home
Facilitating people with modern heating systems
Cheap electricity in winter
Shifting of industries and Electricity generation plants out of the city
Subsidized loans and Tax immunity on industry-shifting
Deforestation and de-vegetation banned
Facilitation of public transport and discouragement of private cars
Standards of gasoline fuels were improved
After implementation, this act took London out of this situation in just 4 years. The following graphs show the 1952 and current situation and concentration of smoke and Sulphur dioxide from 1952 to 2000.
London is currently in very safe air quality limits and esthetically and health-wise having great living standards.
The Lahore air contains 200ug/m3 concentration of PM2.5 which is much higher than permissible limits of international standards. It contains a high concentration of Carbon monoxide, Sulphur and Nitrogen compounds. Oxygen concentration is very low up to 300 feet height in Lahore’s atmosphere, according to environmental experts, spending 1 day in Lahore’s environment is equal to smoking 50 cigarettes for lungs. Around 0.4 million people’s health is severely affected because of that smog. It is the need of time for Lahore to learn from London experience and develop and implement its water quality act.
It’s important to note that smog affects everyone differently, and some people are more susceptible to its negative effects. Unfortunately, in Pakistan, there is no any air quality monitoring facility so that we can timely aware the masses about the dangerous effects of air pollution, in this regard Government of Pakistan should take necessary steps. It is the fundamental right of every Pakistani to enjoy a clean and healthy environment. It is the right of every working man and woman to be able to get to work and home again without getting sick. It is the right of every child to play outdoors without acquiring the respiratory disease. According to the Economic Survey of Pakistan, oil consumption of the country has been increased by 263%. In Pakistan, we need to minimize the major source of air pollution: We should minimize the smoke emission of vehicles, and smoke from industries, burning of solid waste and dust, etc. There are farming equipment’s available that can clear the land without using fire or that can plant seeds without the need to clear the land, as the old dried drop is mixed in the soil for nutrients, but such equipment is costly and require training or education to operate, both of which the farmers cannot afford. Therefore, I think that if the city of Lahore wants to end the scourge of yearly smog, then they should ban crop burning during dry months, farmers should be provided with free seed planting facility through the government-owned and operated company of seeders. Similarly, the Government of Punjab can incentivize CNG use, as it is much low polluting alternative to gasoline and diesel. Similarly, industries should be shut down during evening which will also reduce the load on natural gas usage, while also reducing electricity load shedding, further reducing the need for diesel or petrol generators, which cause excessive pollution, especially in enclosed markets. A new policy action should be implemented which incorporate industry and power plants shifting, installation of air quality monitoring stations, ban at deforestation and de-vegetation and changing the status of agricultural land, tree plantation and increase in green zones in big cities and control the population rise in big cities.